test(evals): measure Java code intelligence as the user sees it

`pnpm eval` drives the production workbench in Chromium against a release
`openidea-server` and jdtls, and judges each scenario on what the user sees: time to
feedback, to the first result and to the final one, and the results against
`evals/java/golden/`. Scenarios cover navigation, usages, implementations, gutter
markers, code lenses, diagnostics, completion, quick documentation and rename, in
`fixtures/java-app` and a pinned spring-petclinic, warm and cold. The report
(`target/eval/report.json` / `.md`) names each failure's kind, a repro command and the
server commands in the slowest run's window; `--save-baseline` compares later runs.

- The frontend gets `data-*` hooks the scenarios read: usage / chooser rows carry their
  location, the usages popup its loading state and scope, a hint whether it is progress
  and what it answers.
- `smoke/tauriShim.ts`: the in-page Tauri runtime shared by the jsdom smoke tests and
  the evals; `perf/lib/bundle.ts` builds the perf bundle for both.
- `.github/tool-versions.env` pins the language-server versions for Language smoke and
  the evals.
- `.agents/skills/eval`: the measure → fix → prove loop for agents.

.agents/skills/eval/SKILL.md

@@ -0,0 +1,83 @@
+---
+name: eval
+description: Run the code-intelligence evals (`pnpm eval`), pick the worst failing scenario, diagnose it from the attached timeline, fix it, prove the fix with before / after numbers measured on this machine without regressing other scenarios, and open one PR. Use for "跑 eval", "优化 Java 代码智能", "eval 失败了", an issue labelled `eval`, or any change to Java navigation / usages / gutter markers that needs numbers.
+---
+
+# Eval loop: measure → fix → prove
+
+`pnpm eval` drives the production workbench in Chromium against a release `openidea-server`
+with real language servers (Java / jdtls for now) and judges every scenario on what the user
+sees: time to feedback, to the first result, to the final one, and the results themselves vs
+`evals/<language>/golden/`. One machine, before and after: numbers from different machines or
+from the nightly host don't judge a fix.
+
+## 0. Preconditions
+
+- `jdtls` on PATH and `JAVA_HOME` pointing at a JDK of the pinned `JAVA` version (projects
+  compile against it, and the JDK scenarios' results are in its sources; jdtls itself runs on
+  a newer installed JDK when it needs one). Pinned versions: `.github/tool-versions.env`. A
+  mismatch prints a warning and the report records both: say so in the PR when it applies.
+- First run builds `cargo build --release -p ide-host --bin openidea-server` and the perf
+  bundle; later iterations of a frontend-only change can use `--no-build` after a
+  `pnpm exec vite build --mode perf --outDir target/eval/dist`, a backend-only one after the
+  cargo build alone.
+- Run evals one at a time on this machine, with nothing heavy (builds, other evals) beside them.
+
+## 1. Baseline on the base commit
+
+```sh
+git switch --detach origin/main     # or the fix branch's merge base
+pnpm eval --save-baseline           # target/eval/baseline.json, this machine only
+```
+
+Read `target/eval/report.json`. Each verdict has `status`, `failures` (`kind`: `error`,
+`timeout`, `degraded`, `correctness`, `budget`, `golden`), `regressions`, `repro` (the command
+that reruns it) and, for failures, `diagnostics`: every command sent to the server in the
+slowest run's window (`cmd`, `start`, `ms`, `ok`, `bytes`, `items`), background tasks, server
+status changes and the server's log tail.
+
+## 2. Pick one problem
+
+Worst first: wrong or missing results and silent degradation, then timeouts, then the
+feedback budget (100 ms), then the slowest `completeMs`. One problem per PR. Say which
+scenario and metric, with its value vs budget.
+
+## 3. Diagnose from the timeline
+
+- Commands in the window ordered by `start`: what ran, what waited on what, what's serial
+  that could overlap, which request returned many `items`/`bytes`, which failed.
+- `feedbackMs` far above 16 ms with a fast `firstResultMs`: the UI shows nothing while it
+  waits (a hint or popup that only appears after a delay).
+- A task still running across the window: background work competing with the request.
+- For the frontend side rerun with `--trace` and open `target/eval/traces/<id>@<cond>.json`
+  in Chrome's Performance panel.
+- Name the cause at class level (as in `issue-fix`): it usually affects sibling scenarios.
+
+## 4. Fix, then rerun that scenario until it passes
+
+```sh
+pnpm eval --only <scenario> --condition <warm|cold>   # the verdict's `repro`
+```
+
+Correctness is enforced, so a faster answer that drops, truncates or serves stale results
+fails. Don't trade a budget miss for a degraded answer.
+
+## 5. Full suite, then PR
+
+```sh
+pnpm eval                           # vs the baseline from step 1: no new failures or regressions
+```
+
+PR per `issue-fix` §6, plus in **How it was verified** the before / after table from
+`target/eval/report.md` (both on this machine, commits named) and the tool versions line.
+
+## Guard rails
+
+- Goldens (`evals/*/golden/`) and budgets (`evals/budgets.json`) are human-owned. Don't edit
+  them, and don't run `--update-golden`, to make a scenario pass. When a golden looks wrong
+  (a tool bump, a deliberate behaviour change), stop and say so: a PR that touches them gets
+  `needs-decision`.
+- Don't weaken a scenario's checks or timeouts in `evals/<language>/scenarios.ts` to pass.
+  Adding a scenario (for a case the sweep or a user found) is fine; record its golden with
+  `--update-golden --only <id>` and ask a person to review the file.
+- A flaky timing (passes on rerun) is not a regression: rerun once before acting on one.

.claude/skills/eval

@@ -0,0 +1 @@
+../../.agents/skills/eval

.github/FUNDING.yml

@@ -0,0 +1,2 @@
+custom:
+  - https://github.com/l0ng-ai/openidea#sponsor

.github/ISSUE_TEMPLATE/config.yml

@@ -3,3 +3,6 @@ contact_links:
   - name: Download the latest release
     url: https://github.com/l0ng-ai/openidea/releases/latest
     about: Many problems are already fixed. Please check the latest version before reporting.
+  - name: Report a security vulnerability
+    url: https://github.com/l0ng-ai/openidea/security/advisories/new
+    about: Please report security problems privately, not in a public issue.

.github/tool-versions.env

@@ -0,0 +1,14 @@
+# Language server and tool versions for Language smoke (.github/workflows/language-smoke.yml)
+# and the code-intelligence evals (pnpm eval). Pinned so a release can't fail an unrelated
+# PR or move a golden result; bump them deliberately (and re-record goldens: pnpm eval --update-golden).
+VTSLS=0.3.0
+TYPESCRIPT=6.0.3
+BASEDPYRIGHT=1.40.2
+RUFF=0.17.3
+GOPLS=v0.24.0
+JDTLS=1.63.0-202610191322
+KOTLIN_LSP=263.7084.0
+GRADLE=8.14.3
+INTELEPHENSE=1.18.5
+# The JDK projects compile against (JAVA_HOME): library navigation opens its sources.
+JAVA=21

.github/workflows/ci.yml

@@ -103,7 +103,7 @@ jobs:
         if: runner.os == 'Linux'
         run: git diff --exit-code src/bindings.ts
 
-  # The remote development server ships as a static Linux binary (release.yml):
+  # The remote development server ships as a static Linux binary (release-build.yml):
   # keep that build working.
   server:
     name: Remote server (linux musl)

.github/workflows/language-smoke.yml

@@ -24,6 +24,7 @@ on:
       - "package.json"
       - "pnpm-lock.yaml"
       - ".github/workflows/language-smoke.yml"
+      - ".github/tool-versions.env"
   pull_request:
     branches: [main]
     types: [opened, synchronize, reopened]
@@ -38,15 +39,6 @@ concurrency:
 env:
   CARGO_TERM_COLOR: always
   CARGO_INCREMENTAL: 0
-  # Pinned so a server release can't fail an unrelated PR; bump them deliberately.
-  VTSLS: 0.3.0
-  TYPESCRIPT: 6.0.3
-  BASEDPYRIGHT: 1.40.2
-  RUFF: 0.17.3
-  GOPLS: v0.24.0
-  JDTLS: 1.63.0-202610191322
-  KOTLIN_LSP: 263.7084.0
-  GRADLE: 8.14.3
 
 jobs:
   smoke:
@@ -54,11 +46,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        language: [typescript, python, rust, go, java, kotlin]
-    runs-on: ubuntu-22.04
+        language: [typescript, python, rust, go, java, kotlin, php, c, cpp]
+    # C/C++ debug with GDB, whose DAP interpreter needs 14+: 22.04 ships 12.1, 24.04 ships 15.
+    runs-on: ${{ (matrix.language == 'c' || matrix.language == 'cpp') && 'ubuntu-24.04' || 'ubuntu-22.04' }}
     timeout-minutes: 40
     steps:
       - uses: actions/checkout@v4
+      # Tool versions, shared with the evals (pnpm eval).
+      - run: grep -E '^[A-Z0-9_]+=' .github/tool-versions.env >> "$GITHUB_ENV"
       - uses: dtolnay/rust-toolchain@stable
         with: { components: "rust-analyzer, rustfmt" }
       # One build cache for every language; main saves it.
@@ -74,6 +69,12 @@ jobs:
       - if: matrix.language == 'typescript'
         run: npm install --global "@vtsls/language-server@$VTSLS" "typescript@$TYPESCRIPT"
 
+      # The smoke builds the c-app fixture and debugs it with GDB's own DAP interpreter.
+      - if: matrix.language == 'c' || matrix.language == 'cpp'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y gdb
+
       - if: matrix.language == 'python'
         uses: actions/setup-python@v5
         with: { python-version: "3.12" }
@@ -88,7 +89,7 @@ jobs:
 
       - if: matrix.language == 'java' || matrix.language == 'kotlin'
         uses: actions/setup-java@v4
-        with: { distribution: temurin, java-version: "21" }
+        with: { distribution: temurin, java-version: "${{ env.JAVA }}" }
       - if: matrix.language == 'java'
         run: |
           mkdir -p "$RUNNER_TEMP/jdtls"
@@ -108,6 +109,13 @@ jobs:
           ln -s "$RUNNER_TEMP/kotlin-lsp/kotlin-lsp.sh" "$RUNNER_TEMP/bin/kotlin-lsp"
           echo "$RUNNER_TEMP/bin" >> "$GITHUB_PATH"
 
+      # Xdebug for the debug smoke; Composer installs the fixture's Pest for the run smoke.
+      - if: matrix.language == 'php'
+        uses: shivammathur/setup-php@v2
+        with: { php-version: "8.5", coverage: xdebug, tools: composer }
+      - if: matrix.language == 'php'
+        run: npm install --global "intelephense@$INTELEPHENSE"
+
       - run: cargo test --locked -p ide-host --test language_smoke --no-run
       - run: cargo test --locked -p ide-host --test language_smoke -- --ignored --exact ${{ matrix.language }}
       - if: matrix.language == 'java'

.github/workflows/nightly.yml

@@ -0,0 +1,119 @@
+name: Nightly
+
+# Twice a day, builds the newest main commit that passed CI as a prerelease tagged with its own
+# version, so remote development finds the server of that version. The `nightly` release holds
+# the manifest the nightly app updates from; its tag marks the commit last built, and a run with
+# nothing newer stops there. Only the latest builds are kept.
+on:
+  schedule:
+    - cron: "17 2,14 * * *"
+  workflow_dispatch:
+    inputs:
+      force:
+        description: "Build even if nothing is newer than the last nightly"
+        type: boolean
+        default: false
+
+permissions:
+  contents: read
+
+concurrency:
+  group: nightly
+
+env:
+  GH_TOKEN: ${{ github.token }}
+  GH_REPO: ${{ github.repository }}
+
+jobs:
+  prepare:
+    permissions:
+      actions: read
+      contents: write
+    if: github.repository == 'l0ng-ai/openidea'
+    runs-on: ubuntu-latest
+    outputs:
+      sha: ${{ steps.commit.outputs.sha }}
+      tag: ${{ steps.release.outputs.tag }}
+      release_id: ${{ steps.release.outputs.id }}
+    steps:
+      - id: commit
+        env:
+          FORCE: ${{ inputs.force }}
+        run: |
+          sha="$(gh run list --workflow ci.yml --branch main --event push --status success --limit 1 \
+            --json headSha --jq '.[0].headSha // ""')"
+          if [ -z "$sha" ]; then
+            echo "::notice::no main commit has passed CI"
+            exit 0
+          fi
+          # No `nightly` tag yet (the first run): compare fails and the build goes on.
+          status="$(gh api "repos/$GH_REPO/compare/nightly...$sha" --jq .status 2>/dev/null || echo ahead)"
+          if [ "$status" != ahead ] && [ "$FORCE" != true ]; then
+            echo "::notice::$sha is not newer than the last nightly"
+            exit 0
+          fi
+          echo "sha=$sha" >> "$GITHUB_OUTPUT"
+      - uses: actions/checkout@v5
+        if: steps.commit.outputs.sha != ''
+        with: { ref: "${{ steps.commit.outputs.sha }}" }
+      - uses: actions/setup-node@v5
+        if: steps.commit.outputs.sha != ''
+        with: { node-version: 22 }
+      - uses: dtolnay/rust-toolchain@stable
+        if: steps.commit.outputs.sha != ''
+      - id: release
+        if: steps.commit.outputs.sha != ''
+        env:
+          SHA: ${{ steps.commit.outputs.sha }}
+        run: |
+          version="$(node scripts/nightly-prepare.ts "$(date -u +%Y%m%d%H%M)")"
+          tag="v$version"
+          git config user.name "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git commit -am "chore: $tag"
+          git tag "$tag"
+          git push origin "$tag"
+          id="$(gh api -X POST "repos/$GH_REPO/releases" -f tag_name="$tag" -f name="OpenIDEA Nightly $version" \
+            -F draft=true -F prerelease=true -f body="Built from $SHA." --jq .id)"
+          echo "tag=$tag" >> "$GITHUB_OUTPUT"
+          echo "id=$id" >> "$GITHUB_OUTPUT"
+
+  binaries:
+    permissions:
+      contents: write
+    needs: prepare
+    if: needs.prepare.outputs.tag != ''
+    uses: ./.github/workflows/release-build.yml
+    with:
+      tag: ${{ needs.prepare.outputs.tag }}
+      release_id: ${{ needs.prepare.outputs.release_id }}
+    secrets: inherit
+
+  publish:
+    permissions:
+      contents: write
+    needs: [prepare, binaries]
+    runs-on: ubuntu-latest
+    env:
+      TAG: ${{ needs.prepare.outputs.tag }}
+      SHA: ${{ needs.prepare.outputs.sha }}
+      KEEP: 14
+    steps:
+      - name: Publish the build
+        run: gh release edit "$TAG" --tag "$TAG" --draft=false
+      - name: Point the updater at it
+        run: |
+          gh release download "$TAG" -p latest.json -D "$RUNNER_TEMP"
+          gh release view nightly >/dev/null 2>&1 ||
+            gh release create nightly --prerelease --latest=false --target "$SHA" --title "OpenIDEA Nightly" \
+              --notes "The update manifest of the nightly builds, and the commit last built."
+          gh release upload nightly "$RUNNER_TEMP/latest.json" --clobber
+          gh api -X PATCH "repos/$GH_REPO/git/refs/tags/nightly" -f sha="$SHA" -F force=true --silent
+      # Failed builds' drafts go too, once they are this old.
+      - name: Delete old builds
+        run: |
+          gh release list --limit 200 --json tagName,createdAt --jq \
+            '[.[] | select(.tagName | contains("-nightly."))] | sort_by(.createdAt) | reverse | .[env.KEEP | tonumber:][].tagName' |
+            while read -r tag; do
+              gh release delete "$tag" --cleanup-tag --yes
+            done

.github/workflows/release-build.yml

@@ -0,0 +1,283 @@
+name: Release build
+
+# Builds a tag's desktop apps, remote servers and updater manifest into its draft release.
+# Stable releases (release.yml) and nightly builds (nightly.yml) both run it.
+on:
+  workflow_call:
+    inputs:
+      tag: { type: string, required: true }
+      release_id: { type: string, required: true }
+
+permissions:
+  contents: read
+
+env:
+  CARGO_TERM_COLOR: always
+  CARGO_INCREMENTAL: 0
+  TAG: ${{ inputs.tag }}
+
+jobs:
+  plugin-keys:
+    permissions: {}
+    runs-on: ubuntu-latest
+    outputs:
+      keys: ${{ steps.keys.outputs.keys }}
+    steps:
+      # The official plugins' public key (from PLUGIN_SIGNING_KEY, the seed
+      # `openidea-plugin keygen` writes), built into the app: their packages
+      # must carry its signature whatever the marketplace index lists. Without
+      # the secret the app takes the index's word, as development builds do.
+      - id: keys
+        env:
+          SIGNING_KEY: ${{ secrets.PLUGIN_SIGNING_KEY }}
+        run: |
+          if [ -n "$SIGNING_KEY" ]; then
+            seed="$(printf %s "$SIGNING_KEY" | base64 -d | od -An -tx1 | tr -d ' \n')"
+            key="$(printf '302e020100300506032b657004220420%s' "$seed" | xxd -r -p |
+              openssl pkey -inform DER -pubout -outform DER | tail -c 32 | base64)"
+            echo "keys=$key" >> "$GITHUB_OUTPUT"
+          fi
+
+  build:
+    permissions:
+      contents: write
+    needs: plugin-keys
+    name: Build (${{ matrix.name }})
+    env:
+      OPENIDEA_OFFICIAL_PLUGIN_KEYS: ${{ needs.plugin-keys.outputs.keys }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: macOS arm64
+            os: macos-latest
+            target: aarch64-apple-darwin
+          - name: macOS x64
+            os: macos-latest
+            target: x86_64-apple-darwin
+          - name: Linux x64
+            os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
+          - name: Linux arm64
+            os: ubuntu-22.04-arm
+            target: aarch64-unknown-linux-gnu
+          - name: Windows arm64
+            os: windows-11-arm
+            target: aarch64-pc-windows-msvc
+          - name: Windows x64
+            os: windows-latest
+            target: x86_64-pc-windows-msvc
+    runs-on: ${{ matrix.os }}
+    steps:
+      - uses: actions/checkout@v5
+        with: { ref: "${{ env.TAG }}" }
+      - uses: pnpm/action-setup@v5
+        with: { version: 11 }
+      - uses: actions/setup-node@v5
+        with: { node-version: 22, cache: pnpm }
+      - uses: dtolnay/rust-toolchain@stable
+        with: { targets: "${{ matrix.target }}" }
+      - uses: Swatinem/rust-cache@v2
+        with: { key: "${{ matrix.target }}" }
+      - name: Linux deps
+        if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y libwebkit2gtk-4.1-dev libayatana-appindicator3-dev librsvg2-dev libxdo-dev libssl-dev patchelf
+      - run: pnpm install --frozen-lockfile
+      # Signing is optional: only secrets that are set get exported, so forks and
+      # unconfigured repos produce unsigned builds instead of failing.
+      - name: Signing env
+        shell: bash
+        env:
+          APPLE_CERTIFICATE: ${{ runner.os == 'macOS' && secrets.APPLE_CERTIFICATE || '' }}
+          APPLE_CERTIFICATE_PASSWORD: ${{ runner.os == 'macOS' && secrets.APPLE_CERTIFICATE_PASSWORD || '' }}
+          APPLE_SIGNING_IDENTITY: ${{ runner.os == 'macOS' && secrets.APPLE_SIGNING_IDENTITY || '' }}
+          APPLE_ID: ${{ runner.os == 'macOS' && secrets.APPLE_ID || '' }}
+          APPLE_PASSWORD: ${{ runner.os == 'macOS' && secrets.APPLE_PASSWORD || '' }}
+          APPLE_TEAM_ID: ${{ runner.os == 'macOS' && secrets.APPLE_TEAM_ID || '' }}
+          TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
+          TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY_PASSWORD }}
+        run: |
+          for v in APPLE_CERTIFICATE APPLE_CERTIFICATE_PASSWORD APPLE_SIGNING_IDENTITY APPLE_ID \
+                   APPLE_PASSWORD APPLE_TEAM_ID TAURI_SIGNING_PRIVATE_KEY TAURI_SIGNING_PRIVATE_KEY_PASSWORD; do
+            [ -n "${!v}" ] && { echo "$v<<__EOF__"; echo "${!v}"; echo "__EOF__"; } >> "$GITHUB_ENV"
+          done
+          true
+      - uses: tauri-apps/tauri-action@v0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          releaseId: ${{ inputs.release_id }}
+          tagName: ${{ env.TAG }}
+          args: --target ${{ matrix.target }}
+          # The parallel builds would race on one latest.json; `updater-manifest` writes it once.
+          uploadUpdaterJson: false
+      # tauri-action notarizes the .app but not the DMG around it; notarize and
+      # staple the DMG too, then replace the uploaded asset.
+      - name: Notarize DMG
+        if: runner.os == 'macOS' && env.APPLE_ID != ''
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          for dmg in target/${{ matrix.target }}/release/bundle/dmg/*.dmg; do
+            xcrun notarytool submit "$dmg" --apple-id "$APPLE_ID" --password "$APPLE_PASSWORD" \
+              --team-id "$APPLE_TEAM_ID" --wait
+            xcrun stapler staple "$dmg"
+            # Release assets have no spaces: GitHub stored the first upload with dots.
+            asset="$RUNNER_TEMP/$(basename "$dmg" | tr ' ' .)"
+            cp "$dmg" "$asset"
+            gh release upload "$TAG" "$asset" --clobber
+          done
+      # Portable Windows builds (#1857): on Windows Tauri embeds the
+      # frontend in the exe and WebView2 is a system component, so zipping
+      # the raw exe gives an unpack-and-run alternative to the installers.
+      - name: Portable zip
+        if: runner.os == 'Windows'
+        shell: pwsh
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          $target = "${{ matrix.target }}"
+          $arch = if ($target -like "x86_64*") { "x64" } else { "arm64" }
+          $version = $env:TAG -replace '^v', ''
+          $asset = "OpenIDEA_${version}_windows_${arch}_portable.zip"
+          $dir = "target/$target/release"
+          $files = @("$dir/openidea.exe")
+          if (Test-Path "$dir/WebView2Loader.dll") {
+            $files += "$dir/WebView2Loader.dll"
+          }
+          Compress-Archive -Path $files -DestinationPath $asset -Force
+          $hash = (Get-FileHash $asset -Algorithm SHA256).Hash.ToLower()
+          "$hash  $asset" | Out-File -Encoding ascii "$asset.sha256"
+          gh release upload $env:TAG $asset "$asset.sha256" --clobber
+
+  # The remote development server, per host platform it can run on. The desktop
+  # app downloads the one for the host (ide-tools `server`) and installs it over SSH.
+  # Linux builds are static (musl), so they run whatever the host's glibc.
+  server:
+    permissions:
+      contents: write
+    name: Server (${{ matrix.os }}-${{ matrix.arch }})
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { runner: ubuntu-22.04, target: x86_64-unknown-linux-musl, os: linux, arch: x86_64 }
+          - { runner: ubuntu-24.04-arm, target: aarch64-unknown-linux-musl, os: linux, arch: aarch64 }
+          - { runner: macos-latest, target: aarch64-apple-darwin, os: macos, arch: aarch64 }
+          - { runner: macos-latest, target: x86_64-apple-darwin, os: macos, arch: x86_64 }
+    runs-on: ${{ matrix.runner }}
+    steps:
+      - uses: actions/checkout@v5
+        with: { ref: "${{ env.TAG }}" }
+      - uses: dtolnay/rust-toolchain@stable
+        with: { targets: "${{ matrix.target }}" }
+      - uses: Swatinem/rust-cache@v2
+        with: { key: "server-${{ matrix.target }}" }
+      - name: musl toolchain
+        if: runner.os == 'Linux'
+        run: sudo apt-get update && sudo apt-get install -y musl-tools
+      - name: Build
+        run: |
+          # musl-tools only ships `musl-gcc`; cc-rs would look for `<arch>-linux-musl-gcc`.
+          if [ "$RUNNER_OS" = Linux ]; then export CC_${TARGET//-/_}=musl-gcc; fi
+          cargo build --release --locked -p ide-host --bin openidea-server --target "$TARGET"
+        env:
+          TARGET: ${{ matrix.target }}
+      - name: Upload
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ASSET: openidea-server-${{ matrix.os }}-${{ matrix.arch }}.gz
+        run: |
+          gzip -9 -c target/${{ matrix.target }}/release/openidea-server > "$ASSET"
+          if command -v sha256sum >/dev/null; then sha256sum "$ASSET"; else shasum -a 256 "$ASSET"; fi > "$ASSET.sha256"
+          gh release upload "$TAG" "$ASSET" "$ASSET.sha256" --clobber
+
+  # The updater manifest (latest.json), built once from the signed bundles every build uploaded.
+  # Fails when a platform is missing, so a release never ships a manifest without it.
+  updater-manifest:
+    permissions:
+      contents: write
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/github-script@v8
+        env:
+          RELEASE_ID: ${{ inputs.release_id }}
+        with:
+          script: |
+            const { owner, repo } = context.repo;
+            const release_id = Number(process.env.RELEASE_ID);
+            const tag = process.env.TAG;
+            const assets = await github.paginate(github.rest.repos.listReleaseAssets, { owner, repo, release_id });
+            const sigs = assets.filter((a) => a.name.endsWith(".sig"));
+            if (sigs.length === 0) {
+              core.notice("no signed bundles (TAURI_SIGNING_PRIVATE_KEY unset): skipping latest.json");
+              return;
+            }
+            // Bundle suffix → updater platform keys, as tauri-action names them.
+            // Nightly versions don't fit MSI or RPM, so those builds offer NSIS on Windows.
+            const nightly = tag.includes("-nightly.");
+            const windows = (arch, msi, nsis) => nightly
+              ? [[nsis, [`windows-${arch}`, `windows-${arch}-nsis`]]]
+              : [[msi, [`windows-${arch}`, `windows-${arch}-msi`]], [nsis, [`windows-${arch}-nsis`]]];
+            const kinds = [
+              [/_aarch64\.AppImage$/, ["linux-aarch64", "linux-aarch64-appimage"]],
+              [/_arm64\.deb$/, ["linux-aarch64-deb"]],
+              ...(nightly ? [] : [[/\.aarch64\.rpm$/, ["linux-aarch64-rpm"]]]),
+              [/_amd64\.AppImage$/, ["linux-x86_64", "linux-x86_64-appimage"]],
+              [/_amd64\.deb$/, ["linux-x86_64-deb"]],
+              ...(nightly ? [] : [[/\.x86_64\.rpm$/, ["linux-x86_64-rpm"]]]),
+              [/_aarch64\.app\.tar\.gz$/, ["darwin-aarch64", "darwin-aarch64-app"]],
+              [/_x64\.app\.tar\.gz$/, ["darwin-x86_64", "darwin-x86_64-app"]],
+              ...windows("aarch64", /_arm64_en-US\.msi$/, /_arm64-setup\.exe$/),
+              ...windows("x86_64", /_x64_en-US\.msi$/, /_x64-setup\.exe$/),
+            ];
+            const platforms = {};
+            for (const sig of sigs) {
+              const bundle = sig.name.slice(0, -".sig".length);
+              const kind = kinds.find(([re]) => re.test(bundle));
+              if (!kind) continue;
+              const { data } = await github.rest.repos.getReleaseAsset({
+                owner, repo, asset_id: sig.id, headers: { accept: "application/octet-stream" },
+              });
+              const signature = Buffer.from(data).toString("utf8").trim();
+              const url = `https://github.com/${owner}/${repo}/releases/download/${tag}/${encodeURIComponent(bundle)}`;
+              for (const key of kind[1]) platforms[key] = { signature, url };
+            }
+            const missing = kinds.flatMap(([, keys]) => keys).filter((k) => !platforms[k]);
+            if (missing.length) {
+              core.setFailed(`latest.json would miss ${missing.join(", ")}`);
+              return;
+            }
+            // The update's notes: the release body without its Download section. That
+            // section only matters on the release page, and What's new follows it.
+            const { data: release } = await github.rest.repos.getRelease({ owner, repo, release_id });
+            const withoutDownloadSection = (body) => {
+              const kept = [];
+              let skip = 0;
+              for (const line of body.split(/\r?\n/)) {
+                const heading = /^(#{1,6})\s+(.*)$/.exec(line);
+                if (heading) {
+                  const level = heading[1].length;
+                  if (!skip && level <= 3 && /^download$/i.test(heading[2].trim())) {
+                    skip = level;
+                    continue;
+                  }
+                  if (skip && level <= skip) skip = 0;
+                }
+                if (!skip) kept.push(line);
+              }
+              return kept.join("\n").trim();
+            };
+            const notes = withoutDownloadSection(String(release.body ?? ""));
+            const manifest = { version: tag.replace(/^v/, ""), notes, pub_date: new Date().toISOString(), platforms };
+            const old = assets.find((a) => a.name === "latest.json");
+            if (old) await github.rest.repos.deleteReleaseAsset({ owner, repo, asset_id: old.id });
+            await github.rest.repos.uploadReleaseAsset({
+              owner, repo, release_id, name: "latest.json",
+              data: JSON.stringify(manifest, null, 2),
+              headers: { "content-type": "application/json" },
+            });
+            core.info(`latest.json: ${Object.keys(platforms).sort().join(", ")}`);

.github/workflows/release.yml

@@ -1,7 +1,7 @@
 name: Release
 on:
   push:
-    tags: ["v*"]
+    tags: ["v*", "!v*-nightly.*"]
   workflow_dispatch:
     inputs:
       tag:
@@ -9,7 +9,7 @@ on:
         required: true
 
 permissions:
-  contents: write
+  contents: read
 
 concurrency:
   group: release-${{ github.event.inputs.tag || github.ref_name }}
@@ -23,10 +23,12 @@ env:
 jobs:
   # Creates (or reuses) one draft release that every platform build uploads into.
   create-release:
+    if: ${{ !contains(github.event.inputs.tag || github.ref_name, '-nightly.') }}
+    permissions:
+      contents: write
     runs-on: ubuntu-latest
     outputs:
       release_id: ${{ steps.release.outputs.id }}
-      official_plugin_keys: ${{ steps.plugin-keys.outputs.keys }}
     steps:
       - uses: actions/checkout@v5
         with: { ref: "${{ env.TAG }}" }
@@ -47,20 +49,6 @@ jobs:
             echo "::error::plugin API $(api wit) ships without a snapshot ($snapshot is $(api "$snapshot")): copy wit/*.wit to $snapshot/"
             exit 1
           fi
-      # The official plugins' public key (from PLUGIN_SIGNING_KEY, the seed
-      # `openidea-plugin keygen` writes), built into the app: their packages
-      # must carry its signature whatever the marketplace index lists. Without
-      # the secret the app takes the index's word, as development builds do.
-      - id: plugin-keys
-        env:
-          SIGNING_KEY: ${{ secrets.PLUGIN_SIGNING_KEY }}
-        run: |
-          if [ -n "$SIGNING_KEY" ]; then
-            seed="$(printf %s "$SIGNING_KEY" | base64 -d | od -An -tx1 | tr -d ' \n')"
-            key="$(printf '302e020100300506032b657004220420%s' "$seed" | xxd -r -p |
-              openssl pkey -inform DER -pubout -outform DER | tail -c 32 | base64)"
-            echo "keys=$key" >> "$GITHUB_OUTPUT"
-          fi
       - id: release
         uses: actions/github-script@v8
         with:
@@ -74,161 +62,26 @@ jobs:
               core.setOutput("id", existing.id);
               return;
             }
+            // Nightly builds are prereleases: the notes span stable release to stable release.
+            const previous = releases.find((r) => !r.draft && !r.prerelease);
+            const { data: notes } = await github.rest.repos.generateReleaseNotes({
+              owner, repo, tag_name: tag, previous_tag_name: previous?.tag_name,
+            });
             const { data } = await github.rest.repos.createRelease({
               owner, repo, tag_name: tag, name: `OpenIDEA ${tag}`,
-              draft: true, prerelease: tag.includes("-"), generate_release_notes: true,
+              draft: true, prerelease: tag.includes("-"), body: notes.body,
             });
             core.setOutput("id", data.id);
 
-  build:
+  binaries:
+    permissions:
+      contents: write
     needs: create-release
-    name: Build (${{ matrix.name }})
-    env:
-      OPENIDEA_OFFICIAL_PLUGIN_KEYS: ${{ needs.create-release.outputs.official_plugin_keys }}
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - name: macOS arm64
-            os: macos-latest
-            target: aarch64-apple-darwin
-          - name: macOS x64
-            os: macos-latest
-            target: x86_64-apple-darwin
-          - name: Linux x64
-            os: ubuntu-22.04
-            target: x86_64-unknown-linux-gnu
-          - name: Linux arm64
-            os: ubuntu-22.04-arm
-            target: aarch64-unknown-linux-gnu
-          - name: Windows arm64
-            os: windows-11-arm
-            target: aarch64-pc-windows-msvc
-          - name: Windows x64
-            os: windows-latest
-            target: x86_64-pc-windows-msvc
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v5
-        with: { ref: "${{ env.TAG }}" }
-      - uses: pnpm/action-setup@v5
-        with: { version: 11 }
-      - uses: actions/setup-node@v5
-        with: { node-version: 22, cache: pnpm }
-      - uses: dtolnay/rust-toolchain@stable
-        with: { targets: "${{ matrix.target }}" }
-      - uses: Swatinem/rust-cache@v2
-        with: { key: "${{ matrix.target }}" }
-      - name: Linux deps
-        if: runner.os == 'Linux'
-        run: |
-          sudo apt-get update
-          sudo apt-get install -y libwebkit2gtk-4.1-dev libayatana-appindicator3-dev librsvg2-dev libxdo-dev libssl-dev patchelf
-      - run: pnpm install --frozen-lockfile
-      # Signing is optional: only secrets that are set get exported, so forks and
-      # unconfigured repos produce unsigned builds instead of failing.
-      - name: Signing env
-        shell: bash
-        env:
-          APPLE_CERTIFICATE: ${{ secrets.APPLE_CERTIFICATE }}
-          APPLE_CERTIFICATE_PASSWORD: ${{ secrets.APPLE_CERTIFICATE_PASSWORD }}
-          APPLE_SIGNING_IDENTITY: ${{ secrets.APPLE_SIGNING_IDENTITY }}
-          APPLE_ID: ${{ secrets.APPLE_ID }}
-          APPLE_PASSWORD: ${{ secrets.APPLE_PASSWORD }}
-          APPLE_TEAM_ID: ${{ secrets.APPLE_TEAM_ID }}
-          TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
-          TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY_PASSWORD }}
-        run: |
-          for v in APPLE_CERTIFICATE APPLE_CERTIFICATE_PASSWORD APPLE_SIGNING_IDENTITY APPLE_ID \
-                   APPLE_PASSWORD APPLE_TEAM_ID TAURI_SIGNING_PRIVATE_KEY TAURI_SIGNING_PRIVATE_KEY_PASSWORD; do
-            [ -n "${!v}" ] && { echo "$v<<__EOF__"; echo "${!v}"; echo "__EOF__"; } >> "$GITHUB_ENV"
-          done
-          true
-      - uses: tauri-apps/tauri-action@v0
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        with:
-          releaseId: ${{ needs.create-release.outputs.release_id }}
-          tagName: ${{ env.TAG }}
-          args: --target ${{ matrix.target }}
-          # The parallel builds would race on one latest.json; `updater-manifest` writes it once.
-          uploadUpdaterJson: false
-      # tauri-action notarizes the .app but not the DMG around it; notarize and
-      # staple the DMG too, then replace the uploaded asset.
-      - name: Notarize DMG
-        if: runner.os == 'macOS' && env.APPLE_ID != ''
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          for dmg in target/${{ matrix.target }}/release/bundle/dmg/*.dmg; do
-            xcrun notarytool submit "$dmg" --apple-id "$APPLE_ID" --password "$APPLE_PASSWORD" \
-              --team-id "$APPLE_TEAM_ID" --wait
-            xcrun stapler staple "$dmg"
-            gh release upload "$TAG" "$dmg" --clobber
-          done
-      # Portable Windows builds (#1857): on Windows Tauri embeds the
-      # frontend in the exe and WebView2 is a system component, so zipping
-      # the raw exe gives an unpack-and-run alternative to the installers.
-      - name: Portable zip
-        if: runner.os == 'Windows'
-        shell: pwsh
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: |
-          $target = "${{ matrix.target }}"
-          $arch = if ($target -like "x86_64*") { "x64" } else { "arm64" }
-          $version = $env:TAG -replace '^v', ''
-          $asset = "OpenIDEA_${version}_windows_${arch}_portable.zip"
-          $dir = "target/$target/release"
-          $files = @("$dir/openidea.exe")
-          if (Test-Path "$dir/WebView2Loader.dll") {
-            $files += "$dir/WebView2Loader.dll"
-          }
-          Compress-Archive -Path $files -DestinationPath $asset -Force
-          $hash = (Get-FileHash $asset -Algorithm SHA256).Hash.ToLower()
-          "$hash  $asset" | Out-File -Encoding ascii "$asset.sha256"
-          gh release upload $env:TAG $asset "$asset.sha256" --clobber
-
-  # The remote development server, per host platform it can run on. The desktop
-  # app downloads the one for the host (ide-tools `server`) and installs it over SSH.
-  # Linux builds are static (musl), so they run whatever the host's glibc.
-  server:
-    needs: create-release
-    name: Server (${{ matrix.os }}-${{ matrix.arch }})
-    strategy:
-      fail-fast: false
-      matrix:
-        include:
-          - { runner: ubuntu-22.04, target: x86_64-unknown-linux-musl, os: linux, arch: x86_64 }
-          - { runner: ubuntu-24.04-arm, target: aarch64-unknown-linux-musl, os: linux, arch: aarch64 }
-          - { runner: macos-latest, target: aarch64-apple-darwin, os: macos, arch: aarch64 }
-          - { runner: macos-latest, target: x86_64-apple-darwin, os: macos, arch: x86_64 }
-    runs-on: ${{ matrix.runner }}
-    steps:
-      - uses: actions/checkout@v5
-        with: { ref: "${{ env.TAG }}" }
-      - uses: dtolnay/rust-toolchain@stable
-        with: { targets: "${{ matrix.target }}" }
-      - uses: Swatinem/rust-cache@v2
-        with: { key: "server-${{ matrix.target }}" }
-      - name: musl toolchain
-        if: runner.os == 'Linux'
-        run: sudo apt-get update && sudo apt-get install -y musl-tools
-      - name: Build
-        run: |
-          # musl-tools only ships `musl-gcc`; cc-rs would look for `<arch>-linux-musl-gcc`.
-          if [ "$RUNNER_OS" = Linux ]; then export CC_${TARGET//-/_}=musl-gcc; fi
-          cargo build --release --locked -p ide-host --bin openidea-server --target "$TARGET"
-        env:
-          TARGET: ${{ matrix.target }}
-      - name: Upload
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          ASSET: openidea-server-${{ matrix.os }}-${{ matrix.arch }}.gz
-        run: |
-          gzip -9 -c target/${{ matrix.target }}/release/openidea-server > "$ASSET"
-          if command -v sha256sum >/dev/null; then sha256sum "$ASSET"; else shasum -a 256 "$ASSET"; fi > "$ASSET.sha256"
-          gh release upload "$TAG" "$ASSET" "$ASSET.sha256" --clobber
+    uses: ./.github/workflows/release-build.yml
+    with:
+      tag: ${{ github.event.inputs.tag || github.ref_name }}
+      release_id: ${{ needs.create-release.outputs.release_id }}
+    secrets: inherit
 
   # The official plugins, signed, and the marketplace index released apps read
   # (releases/latest/download/plugins-index.json). They are not in the
@@ -240,6 +93,8 @@ jobs:
   # openidea-plugin tool for Linux x64, which that workflow and the registry's
   # checks run.
   plugins:
+    permissions:
+      contents: write
     needs: create-release
     name: Official plugins
     runs-on: ubuntu-22.04
@@ -303,70 +158,10 @@ jobs:
           gh release upload "$TAG" "$out"/*.oiplugin "$out/plugins-index.json" \
             "$out/openidea-plugin-linux-x86_64.gz" --clobber
 
-  # The updater manifest (latest.json), built once from the signed bundles every build uploaded.
-  # Fails when a platform is missing, so a release never ships a manifest without it.
-  updater-manifest:
-    needs: [create-release, build]
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/github-script@v8
-        env:
-          RELEASE_ID: ${{ needs.create-release.outputs.release_id }}
-        with:
-          script: |
-            const { owner, repo } = context.repo;
-            const release_id = Number(process.env.RELEASE_ID);
-            const tag = process.env.TAG;
-            const assets = await github.paginate(github.rest.repos.listReleaseAssets, { owner, repo, release_id });
-            const sigs = assets.filter((a) => a.name.endsWith(".sig"));
-            if (sigs.length === 0) {
-              core.notice("no signed bundles (TAURI_SIGNING_PRIVATE_KEY unset): skipping latest.json");
-              return;
-            }
-            // Bundle suffix → updater platform keys, as tauri-action names them.
-            const kinds = [
-              [/_aarch64\.AppImage$/, ["linux-aarch64", "linux-aarch64-appimage"]],
-              [/_arm64\.deb$/, ["linux-aarch64-deb"]],
-              [/\.aarch64\.rpm$/, ["linux-aarch64-rpm"]],
-              [/_amd64\.AppImage$/, ["linux-x86_64", "linux-x86_64-appimage"]],
-              [/_amd64\.deb$/, ["linux-x86_64-deb"]],
-              [/\.x86_64\.rpm$/, ["linux-x86_64-rpm"]],
-              [/_aarch64\.app\.tar\.gz$/, ["darwin-aarch64", "darwin-aarch64-app"]],
-              [/_x64\.app\.tar\.gz$/, ["darwin-x86_64", "darwin-x86_64-app"]],
-              [/_arm64_en-US\.msi$/, ["windows-aarch64", "windows-aarch64-msi"]],
-              [/_arm64-setup\.exe$/, ["windows-aarch64-nsis"]],
-              [/_x64_en-US\.msi$/, ["windows-x86_64", "windows-x86_64-msi"]],
-              [/_x64-setup\.exe$/, ["windows-x86_64-nsis"]],
-            ];
-            const platforms = {};
-            for (const sig of sigs) {
-              const bundle = sig.name.slice(0, -".sig".length);
-              const kind = kinds.find(([re]) => re.test(bundle));
-              if (!kind) continue;
-              const { data } = await github.rest.repos.getReleaseAsset({
-                owner, repo, asset_id: sig.id, headers: { accept: "application/octet-stream" },
-              });
-              const signature = Buffer.from(data).toString("utf8").trim();
-              const url = `https://github.com/${owner}/${repo}/releases/download/${tag}/${encodeURIComponent(bundle)}`;
-              for (const key of kind[1]) platforms[key] = { signature, url };
-            }
-            const missing = kinds.flatMap(([, keys]) => keys).filter((k) => !platforms[k]);
-            if (missing.length) {
-              core.setFailed(`latest.json would miss ${missing.join(", ")}`);
-              return;
-            }
-            const manifest = { version: tag.replace(/^v/, ""), notes: "", pub_date: new Date().toISOString(), platforms };
-            const old = assets.find((a) => a.name === "latest.json");
-            if (old) await github.rest.repos.deleteReleaseAsset({ owner, repo, asset_id: old.id });
-            await github.rest.repos.uploadReleaseAsset({
-              owner, repo, release_id, name: "latest.json",
-              data: JSON.stringify(manifest, null, 2),
-              headers: { "content-type": "application/json" },
-            });
-            core.info(`latest.json: ${Object.keys(platforms).sort().join(", ")}`);
-
   publish:
-    needs: [create-release, build, server, plugins, updater-manifest]
+    permissions:
+      contents: write
+    needs: [create-release, binaries, plugins]
     runs-on: ubuntu-latest
     steps:
       - uses: actions/github-script@v8

.gitignore

@@ -40,6 +40,7 @@ CLAUDE.local.md
 .claude/skills/*
 !.claude/skills/verify
 !.claude/skills/issue-fix
+!.claude/skills/eval
 
 # Local reference screenshots
 pycharm-screenshots/

.oxfmtrc.json

@@ -9,10 +9,11 @@
     "dist",
     "target",
     "src/bindings.ts",
+    "evals/*/golden",
     "src/editor/core/cm/angular/parser*.ts",
     "src/editor/core/cm/jsp/parser*.ts",
     "src/editor/core/cm/astro/parser*.ts",
-    "docs/plugins/themes.md",
+    "plugins/themes.md",
     "pnpm-lock.yaml",
     "**/*.toml",
     "fixtures",

AGENTS.md

@@ -21,11 +21,13 @@ Visual style: dark, low-contrast greys, one cool accent
 - `crates/ide-host` — the `openidea-server` binary for remote development and the
   `openidea-plugin` CLI (plugin starter templates live in its `templates.rs`).
 - `wit/` — plugin interface definitions; `plugins/` — sample and bundled plugins.
-  Plugin docs: `plugins/README.md`, `docs/plugins/themes.md`.
+  Plugin docs: `plugins/README.md`, `plugins/themes.md`.
 - `java/` — JDT LS extension bundles (`java-usages`, `kotlin-bridge`) and the patched
   Lombok agent, embedded into the app by `ide-sdk` / `ide-tools`.
-- `e2e/` — Playwright UI tests (`pnpm e2e`). `fixtures/` — sample projects per language
-  for manual and automated testing.
+- `e2e/` — Playwright UI tests (`pnpm e2e`). `evals/` — code-intelligence evals (`pnpm eval`).
+  `fixtures/` — sample projects per language for manual and automated testing.
+- `docs/` — the Mintlify documentation site (`docs.json` navigation, `en/` and `zh/` pages);
+  preview with `npx mint dev` in `docs/`.
 
 ## Rules
 
@@ -57,9 +59,12 @@ Unclear product decisions → `needs-decision` and stop.
 
 ## Skills
 
+Do not use Impeccable or its related skills in this repository, including globally installed copies.
+
 Shared agent skills live in `.agents/skills/` (`.claude/skills/` links to them):
 `verify` drives the running app through Tauri MCP and captures screenshot evidence;
-`issue-fix` takes an issue from reproduction to one PR.
+`issue-fix` takes an issue from reproduction to one PR;
+`eval` takes a failing code-intelligence eval to a fix with before / after numbers.
 
 ## Commands
 
@@ -79,6 +84,11 @@ Shared agent skills live in `.agents/skills/` (`.claude/skills/` links to them):
   `pnpm gen:bindings`.
 - `pnpm perf` (UI interaction latency / frames / leaks), `pnpm perf:rust` (criterion
   benches vs budgets). Budgets: `perf/budgets.json`.
+- `pnpm eval [--only <id>] [--runs n] [--save-baseline]` — Java code intelligence (navigation,
+  usages, gutter markers) in the production workbench against a release `openidea-server` and
+  jdtls: time to feedback / first result / complete, results vs `evals/<language>/golden/`.
+  Report: `target/eval/report.json`. Goldens and `evals/budgets.json` are changed by people only.
+  Tool versions: `.github/tool-versions.env` (shared with Language smoke).
 - `pnpm release:prepare <version>` — the release commit's changes: app version everywhere,
   `Cargo.lock`, and the plugin API snapshot when `wit/` moved to a new version.
 

Cargo.lock

@@ -1522,7 +1522,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d045de693cb712d0b22c6a64be5b953f67b3ce00ab5ad3dd5d8b441886ab8e1a"
 dependencies = [
  "quote",
- "syn 2.0.119",
+ "syn 3.0.9",
 ]
 
 [[package]]
@@ -1578,16 +1578,6 @@ dependencies = [
  "syn 2.0.119",
 ]
 
-[[package]]
-name = "darling"
-version = "0.13.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a01d95850c592940db9b8194bc39f4bc0e89dee5c4265e4b1807c34a9aba453c"
-dependencies = [
- "darling_core 0.13.4",
- "darling_macro 0.13.4",
-]
-
 [[package]]
 name = "darling"
 version = "0.23.0"
@@ -1608,20 +1598,6 @@ dependencies = [
  "darling_macro 0.24.1",
 ]
 
-[[package]]
-name = "darling_core"
-version = "0.13.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "859d65a907b6852c9361e3185c862aae7fafd2887876799fa55f5f99dc40d610"
-dependencies = [
- "fnv",
- "ident_case",
- "proc-macro2",
- "quote",
- "strsim 0.10.0",
- "syn 1.0.109",
-]
-
 [[package]]
 name = "darling_core"
 version = "0.23.0"
@@ -1631,7 +1607,7 @@ dependencies = [
  "ident_case",
  "proc-macro2",
  "quote",
- "strsim 0.11.1",
+ "strsim",
  "syn 2.0.119",
 ]
 
@@ -1644,21 +1620,10 @@ dependencies = [
  "ident_case",
  "proc-macro2",
  "quote",
- "strsim 0.11.1",
+ "strsim",
  "syn 3.0.9",
 ]
 
-[[package]]
-name = "darling_macro"
-version = "0.13.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c972679f83bdf9c42bd905396b6c3588a843a17f0f16dfcfa3e2c5d57441835"
-dependencies = [
- "darling_core 0.13.4",
- "quote",
- "syn 1.0.109",
-]
-
 [[package]]
 name = "darling_macro"
 version = "0.23.0"
@@ -2685,7 +2650,7 @@ checksum = "ff2abc00be7fca6ebc474524697ae276ad847ad0a6b3faa4bcb027e9a4614ad0"
 dependencies = [
  "cfg-if",
  "libc",
- "wasi",
+ "wasi 0.11.1+wasi-snapshot-preview1",
 ]
 
 [[package]]
@@ -4180,7 +4145,7 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"
 
 [[package]]
 name = "ide-agent"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4204,7 +4169,7 @@ dependencies = [
 
 [[package]]
 name = "ide-analysis"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ast-grep-core",
  "ide-core",
@@ -4218,7 +4183,7 @@ dependencies = [
 
 [[package]]
 name = "ide-android"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "serde",
@@ -4229,11 +4194,13 @@ dependencies = [
 
 [[package]]
 name = "ide-build"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
+ "chardetng",
  "dirs 6.0.0",
  "dunce",
+ "encoding_rs",
  "ide-core",
  "serde",
  "serde_json",
@@ -4245,7 +4212,7 @@ dependencies = [
 
 [[package]]
 name = "ide-cli"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dirs 6.0.0",
  "serde",
@@ -4259,7 +4226,7 @@ dependencies = [
 
 [[package]]
 name = "ide-clipboard"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "gtk",
  "objc2 0.6.5",
@@ -4269,12 +4236,11 @@ dependencies = [
 
 [[package]]
 name = "ide-core"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "encoding_rs",
  "libc",
- "percent-encoding",
  "serde",
  "serde_json",
  "specta",
@@ -4287,7 +4253,7 @@ dependencies = [
 
 [[package]]
 name = "ide-coverage"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "ide-run",
@@ -4301,17 +4267,20 @@ dependencies = [
 
 [[package]]
 name = "ide-dap"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "futures",
  "ide-core",
+ "ide-heap",
+ "ide-jdwp",
  "ide-jsonrpc",
+ "ide-jvm-attach",
+ "ide-jvm-inspect",
  "ide-language",
- "ide-remote",
- "ide-run",
  "libc",
  "memchr",
  "parking_lot",
+ "percent-encoding",
  "portable-pty",
  "serde",
  "serde_json",
@@ -4324,7 +4293,7 @@ dependencies = [
 
 [[package]]
 name = "ide-db"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "bb8",
  "blake3",
@@ -4334,7 +4303,7 @@ dependencies = [
  "ide-core",
  "ide-http",
  "ide-ssh",
- "oracle",
+ "oracledb",
  "parking_lot",
  "reqwest",
  "rustls",
@@ -4354,7 +4323,7 @@ dependencies = [
 
 [[package]]
 name = "ide-docker"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "serde",
@@ -4367,10 +4336,11 @@ dependencies = [
 
 [[package]]
 name = "ide-extension"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "base64 0.22.1",
  "blake3",
+ "dunce",
  "ed25519-dalek",
  "ide-core",
  "parking_lot",
@@ -4387,7 +4357,7 @@ dependencies = [
 
 [[package]]
 name = "ide-fonts"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "objc2-core-foundation",
  "objc2-core-text",
@@ -4399,7 +4369,7 @@ dependencies = [
 
 [[package]]
 name = "ide-github"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "ide-vcs",
@@ -4410,9 +4380,27 @@ dependencies = [
  "which",
 ]
 
+[[package]]
+name = "ide-heap"
+version = "0.1.42"
+dependencies = [
+ "criterion",
+ "ide-core",
+ "libc",
+ "memmap2",
+ "proptest",
+ "serde",
+ "serde_json",
+ "specta",
+ "tempfile",
+ "thiserror 2.0.21",
+ "tracing",
+ "uuid",
+]
+
 [[package]]
 name = "ide-host"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "base64 0.22.1",
  "blake3",
@@ -4432,9 +4420,11 @@ dependencies = [
  "ide-db",
  "ide-docker",
  "ide-extension",
+ "ide-heap",
  "ide-http",
  "ide-index",
  "ide-jsonrpc",
+ "ide-jvm-attach",
  "ide-language",
  "ide-lsp",
  "ide-mcp",
@@ -4442,6 +4432,7 @@ dependencies = [
  "ide-plugin",
  "ide-remote",
  "ide-run",
+ "ide-scaffold",
  "ide-sdk",
  "ide-search",
  "ide-spell",
@@ -4456,7 +4447,6 @@ dependencies = [
  "ignore",
  "jsonschema",
  "parking_lot",
- "percent-encoding",
  "quick-xml 0.42.0",
  "regex-lite",
  "regex-syntax",
@@ -4479,9 +4469,10 @@ dependencies = [
 
 [[package]]
 name = "ide-http"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
+ "ide-vfs",
  "parking_lot",
  "reqwest",
  "rustls",
@@ -4497,7 +4488,7 @@ dependencies = [
 
 [[package]]
 name = "ide-index"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
  "criterion",
@@ -4517,9 +4508,21 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "ide-jdwp"
+version = "0.1.42"
+dependencies = [
+ "ide-jvm-inspect",
+ "proptest",
+ "tempfile",
+ "thiserror 2.0.21",
+ "tokio",
+ "tracing",
+]
+
 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "encoding_rs",
  "futures",
@@ -4534,9 +4537,29 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "ide-jvm-attach"
+version = "0.1.42"
+dependencies = [
+ "libc",
+ "tempfile",
+ "thiserror 2.0.21",
+]
+
+[[package]]
+name = "ide-jvm-inspect"
+version = "0.1.42"
+dependencies = [
+ "futures",
+ "serde",
+ "serde_json",
+ "specta",
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "ide-language"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
  "criterion",
@@ -4592,13 +4615,14 @@ dependencies = [
 
 [[package]]
 name = "ide-lsp"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "futures",
  "globset",
  "ide-core",
  "ide-jsonrpc",
+ "ide-jvm-inspect",
  "ide-language",
  "ide-text",
  "ide-vfs",
@@ -4618,7 +4642,7 @@ dependencies = [
 
 [[package]]
 name = "ide-mcp"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "bytes",
  "dunce",
@@ -4637,7 +4661,7 @@ dependencies = [
 
 [[package]]
 name = "ide-notebook"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "futures",
  "ide-core",
@@ -4660,7 +4684,7 @@ dependencies = [
 
 [[package]]
 name = "ide-plugin"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
  "dunce",
@@ -4683,9 +4707,10 @@ dependencies = [
 
 [[package]]
 name = "ide-profiler"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
+ "ide-jvm-attach",
  "ide-run",
  "serde",
  "serde_json",
@@ -4696,7 +4721,7 @@ dependencies = [
 
 [[package]]
 name = "ide-remote"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "globset",
@@ -4715,7 +4740,7 @@ dependencies = [
 
 [[package]]
 name = "ide-run"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "encoding_rs",
@@ -4737,9 +4762,25 @@ dependencies = [
  "zip",
 ]
 
+[[package]]
+name = "ide-scaffold"
+version = "0.1.42"
+dependencies = [
+ "ide-core",
+ "ide-tools",
+ "ide-vcs",
+ "insta",
+ "serde",
+ "serde_json",
+ "specta",
+ "tempfile",
+ "toml 0.9.12+spec-1.1.0",
+ "tracing",
+]
+
 [[package]]
 name = "ide-sdk"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dunce",
  "ide-core",
@@ -4759,9 +4800,10 @@ dependencies = [
 
 [[package]]
 name = "ide-search"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "criterion",
+ "encoding_rs",
  "globset",
  "grep-matcher",
  "grep-regex",
@@ -4779,7 +4821,7 @@ dependencies = [
 
 [[package]]
 name = "ide-spell"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "parking_lot",
@@ -4792,7 +4834,7 @@ dependencies = [
 
 [[package]]
 name = "ide-ssh"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "dirs 6.0.0",
  "flate2",
@@ -4813,7 +4855,7 @@ dependencies = [
 
 [[package]]
 name = "ide-syntax"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "ide-language",
@@ -4828,7 +4870,7 @@ dependencies = [
 
 [[package]]
 name = "ide-terminal"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "ide-core",
  "libc",
@@ -4841,7 +4883,7 @@ dependencies = [
 
 [[package]]
 name = "ide-text"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "criterion",
  "ide-core",
@@ -4854,7 +4896,7 @@ dependencies = [
 
 [[package]]
 name = "ide-tools"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "flate2",
  "hex",
@@ -4875,7 +4917,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vcs"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
  "dunce",
@@ -4896,7 +4938,7 @@ dependencies = [
 
 [[package]]
 name = "ide-vfs"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "chardetng",
  "dunce",
@@ -4920,11 +4962,11 @@ dependencies = [
 
 [[package]]
 name = "ide-web"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
+ "dirs 6.0.0",
  "ide-core",
  "open",
- "parking_lot",
  "percent-encoding",
  "serde",
  "specta",
@@ -4936,7 +4978,7 @@ dependencies = [
 
 [[package]]
 name = "ide-workspace"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "blake3",
  "dunce",
@@ -5753,7 +5795,7 @@ checksum = "1788edb87fdc09c7e26304471e2f5be8cdefb1b6930d6e3985fc02ff53bf86ee"
 dependencies = [
  "libc",
  "log",
- "wasi",
+ "wasi 0.11.1+wasi-snapshot-preview1",
  "windows-sys 0.61.2",
 ]
 
@@ -6489,15 +6531,6 @@ dependencies = [
  "memchr",
 ]
 
-[[package]]
-name = "odpic-sys"
-version = "0.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "920b5474a5128a9f0232df5a0ffc50aaa5b077b29b8b06ab0131985ac82793ed"
-dependencies = [
- "cc",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.4"
@@ -6523,7 +6556,7 @@ dependencies = [
 
 [[package]]
 name = "openidea"
-version = "0.1.40"
+version = "0.1.42"
 dependencies = [
  "base64 0.22.1",
  "blake3",
@@ -6557,6 +6590,7 @@ dependencies = [
  "ide-profiler",
  "ide-remote",
  "ide-run",
+ "ide-scaffold",
  "ide-sdk",
  "ide-search",
  "ide-spell",
@@ -6611,29 +6645,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
 
 [[package]]
-name = "oracle"
-version = "0.6.3"
+name = "oracledb"
+version = "26.0.0-beta.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3db40fe6e4df881b683691ade5ef1f7b1afd52aefa115581f7b92855524d7ec0"
+checksum = "27b98c7346f2bb5169ec4b2d4f066fb616529ac766b395440c5019fe88d1ef45"
 dependencies = [
- "cc",
- "odpic-sys",
- "once_cell",
- "oracle_procmacro",
- "paste",
- "rustversion",
-]
-
-[[package]]
-name = "oracle_procmacro"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ad247f3421d57de56a0d0408d3249d4b1048a522be2013656d92f022c3d8af27"
-dependencies = [
- "darling 0.13.4",
- "proc-macro2",
- "quote",
- "syn 1.0.109",
+ "aes",
+ "base16ct",
+ "base64ct",
+ "cbc",
+ "chrono",
+ "pbkdf2",
+ "pkcs8",
+ "rand 0.10.3",
+ "rustls",
+ "sha2 0.11.1",
+ "uuid",
+ "webpki-roots",
+ "whoami",
 ]
 
 [[package]]
@@ -7768,9 +7797,9 @@ dependencies = [
 
 [[package]]
 name = "rustix"
-version = "1.1.5"
+version = "1.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "891efababe418670775f199f0d233d84843c227a0949a883ce15b37c78d6629d"
+checksum = "e5e76742e5294153d4dde1207dbec5bdd81eef6fabdc0d2118babadabfd858aa"
 dependencies = [
  "bitflags 2.13.2",
  "errno",
@@ -8920,12 +8949,6 @@ dependencies = [
  "unicode-properties",
 ]
 
-[[package]]
-name = "strsim"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
-
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -8962,7 +8985,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
 dependencies = [
  "proc-macro2",
- "quote",
  "unicode-ident",
 ]
 
@@ -9185,7 +9207,7 @@ dependencies = [
  "serde",
  "serde_json",
  "static_vcruntime",
- "strsim 0.11.1",
+ "strsim",
  "tauri-utils",
  "tauri-winres",
  "walkdir",
@@ -10725,6 +10747,15 @@ version = "0.11.1+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
+[[package]]
+name = "wasi"
+version = "0.14.7+wasi-0.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "883478de20367e224c0090af9cf5f9fa85bed63a95c1abf3afc5c083ebc06e8c"
+dependencies = [
+ "wasip2",
+]
+
 [[package]]
 name = "wasip2"
 version = "1.0.4+wasi-0.2.12"
@@ -10734,6 +10765,15 @@ dependencies = [
  "wit-bindgen",
 ]
 
+[[package]]
+name = "wasite"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "66fe902b4a6b8028a753d5424909b764ccf79b7a209eac9bf97e59cda9f71a42"
+dependencies = [
+ "wasi 0.14.7+wasi-0.2.4",
+]
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.129"
@@ -11317,6 +11357,7 @@ dependencies = [
  "libc",
  "libredox",
  "objc2-system-configuration",
+ "wasite",
  "web-sys",
 ]
 
@@ -12154,14 +12195,15 @@ dependencies = [
 
 [[package]]
 name = "zip"
-version = "9.1.3"
+version = "9.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1156b39d142a34b999c2310a50455e0cb3760bf7efad0122f796d813bee26ccb"
+checksum = "00fb4744e923442ecadfd3f85f51a5d24e03bf43d53813b81ebb4c91d02baa62"
 dependencies = [
  "crc32fast",
  "flate2",
  "getrandom 0.4.3",
  "indexmap 2.14.2",
+ "libc",
  "memchr",
  "nix 0.31.3",
  "typed-path",

Cargo.toml

@@ -5,7 +5,7 @@ members = ["crates/*", "src-tauri"]
 exclude = ["sdk", "plugins"]
 
 [workspace.package]
-version = "0.1.40"
+version = "0.1.42"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"
@@ -43,10 +43,15 @@ ide-ssh = { path = "crates/ide-ssh" }
 ide-remote = { path = "crates/ide-remote" }
 ide-host = { path = "crates/ide-host" }
 ide-mcp = { path = "crates/ide-mcp" }
+ide-scaffold = { path = "crates/ide-scaffold" }
 ide-notebook = { path = "crates/ide-notebook" }
 ide-extension = { path = "crates/ide-extension" }
 ide-plugin = { path = "crates/ide-plugin" }
 ide-cli = { path = "crates/ide-cli" }
+ide-jvm-attach = { path = "crates/ide-jvm-attach" }
+ide-jvm-inspect = { path = "crates/ide-jvm-inspect" }
+ide-jdwp = { path = "crates/ide-jdwp" }
+ide-heap = { path = "crates/ide-heap" }
 
 # serialization & IPC typing
 serde = { version = "1", features = ["derive"] }
@@ -82,7 +87,8 @@ trash = "5"
 blake3 = "1"
 dunce = "1"
 dirs = "6"
-zip = { version = "9", default-features = false, features = ["deflate"] }
+memmap2 = "0.9"
+zip = { version = "9.2.3", default-features = false, features = ["deflate"] }
 
 # search, index, language
 grep-searcher = "0.1"
@@ -106,7 +112,8 @@ rustls-platform-verifier = "0.7"
 # Until SQLx releases its libsqlite3-sys 0.39 update (RUSTSEC-2026-0459).
 sqlx = { version = "0.9", git = "https://github.com/transact-rs/sqlx", rev = "10462fa4414c6c7f1ed1d39bb31678e3b726878c", default-features = false, features = ["runtime-tokio", "tls-rustls-ring-webpki", "sqlite", "postgres", "mysql"] }
 tiberius = { version = "0.13", default-features = false, features = ["tds73", "rustls", "sql-browser-tokio"] }
-oracle = { version = "0.6", default-features = false }
+# Pure-Rust thin Oracle driver; pinned to the beta until it stabilizes.
+oracledb = "=26.0.0-beta.5"
 bb8 = "0.9"
 uuid = { version = "1", features = ["v4"] }
 # OS credential stores

README.md

@@ -12,11 +12,15 @@
 <p align="center">
   <a href="https://github.com/l0ng-ai/openidea/releases/latest"><b>Download</b></a>
   &nbsp;·&nbsp;
+  <a href="https://openidea.sh">Docs</a>
+  &nbsp;·&nbsp;
   <a href="#benchmark">Benchmark</a>
   &nbsp;·&nbsp;
   <a href="#plugins">Plugins</a>
   &nbsp;·&nbsp;
   <a href="#community">Community</a>
+  &nbsp;·&nbsp;
+  <a href="#sponsor">Sponsor</a>
 </p>
 
 https://github.com/user-attachments/assets/234dd54c-1255-4b3a-b35c-533d78d737c0
@@ -25,9 +29,7 @@ OpenIDEA brings the IntelliJ IDEA way of working — its keymap, its tool window
 its search-everything habits — to a native app with a Rust core.
 
 Editor, code insight, debugger, Git, terminal, database and HTTP clients,
-for 60+ languages. Builds for macOS, Windows and Linux. On Windows, if you'd
-rather skip the installer, each release also ships a portable zip — unpack it
-and run `openidea.exe`.
+for 60+ languages. Builds for macOS, Windows and Linux.
 
 ## Benchmark
 
@@ -56,7 +58,7 @@ themes, file icons and languages. They run as sandboxed WebAssembly components;
 themes, icon themes and languages need no code at all.
 
 Install them from Settings › Plugins, or start your own with
-`openidea-plugin new` — see [Writing OpenIDEA plugins](plugins/README.md) and
+`openidea-plugin new` — see [Writing OpenIDEA plugins](https://openidea.sh/en/plugins) and
 the [official plugins](plugins/official). The plugin API is still a preview.
 
 ## Community
@@ -64,18 +66,23 @@ the [official plugins](plugins/official). The plugin API is still a preview.
 - [Discord](https://discord.gg/2Zy4yn7gP) — questions, feedback and release news.
 - WeChat group — scan to join:
 
-  <img src="docs/assets/wechat-group.png" alt="WeChat group QR code" width="200">
+  <img src=".github/assets/wechat-group.png" alt="WeChat group QR code" width="200">
 
-### Contributors
+- Contributing: see [CONTRIBUTING.md](CONTRIBUTING.md) and the [contributor docs](https://openidea.sh/en/contribute/setup).
 
-<a href="https://github.com/l0ng-ai/openidea/graphs/contributors">
-  <img src="https://contrib.rocks/image?repo=l0ng-ai/openidea&max=500" alt="OpenIDEA contributors">
-</a>
+## Sponsor
+
+If OpenIDEA saves you time, you can support its development with Alipay or WeChat Pay.
+
+<table>
+  <tr>
+    <td align="center"><img src=".github/assets/sponsor-alipay.png" alt="Alipay QR code" width="200"><br>Alipay</td>
+    <td align="center"><img src=".github/assets/sponsor-wechat.png" alt="WeChat Pay QR code" width="200"><br>WeChat Pay</td>
+  </tr>
+</table>
 
 ## License
 
 [Apache 2.0](LICENSE). Bundled third-party assets are listed in [`THIRD_PARTY_LICENSES.md`](THIRD_PARTY_LICENSES.md).
 
-
-
 <sub>Not affiliated with JetBrains. IntelliJ IDEA is a trademark of JetBrains s.r.o.</sub>

SECURITY.md

@@ -0,0 +1,26 @@
+# Security policy
+
+## Reporting a vulnerability
+
+Please do not report security problems in public issues, pull requests or discussions.
+
+Report them privately through GitHub:
+[Report a vulnerability](https://github.com/l0ng-ai/openidea/security/advisories/new)
+(repository **Security** tab → **Report a vulnerability**). Only the maintainers can see
+the report.
+
+Include what you can of:
+
+- the affected version, platform, and whether remote development (`openidea-server`)
+  or plugins are involved;
+- steps to reproduce, or a proof of concept;
+- the impact you expect, and any fix you suggest.
+
+We will acknowledge the report, keep you updated in the advisory, and agree on a
+disclosure date with you. Fixes are released as a new version, and the advisory is
+published once users can update.
+
+## Supported versions
+
+Security fixes go into the latest release. Please check that the problem still occurs
+there before reporting.

THIRD_PARTY_LICENSES.md

@@ -1,5 +1,11 @@
 # Third-party licenses
 
+## Project type icons
+
+`src/ui/brands/*.svg` use the unmodified logo paths from
+[Simple Icons](https://github.com/simple-icons/simple-icons), retrieved through
+Iconify (`simple-icons:angular`, `simple-icons:astro`, `simple-icons:cplusplus`, `simple-icons:dart`, `simple-icons:django`, `simple-icons:dotnet`, `simple-icons:elixir`, `simple-icons:express`, `simple-icons:fastapi`, `simple-icons:flask`, `simple-icons:flutter`, `simple-icons:go`, `simple-icons:haskell`, `simple-icons:html5`, `simple-icons:kotlin`, `simple-icons:ktor`, `simple-icons:laravel`, `simple-icons:nestjs`, `simple-icons:nextdotjs`, `simple-icons:nodedotjs`, `simple-icons:nuxt`, `simple-icons:openjdk`, `simple-icons:phoenixframework`, `simple-icons:php`, `simple-icons:python`, `simple-icons:quarkus`, `simple-icons:ruby`, `simple-icons:rubyonrails`, `simple-icons:rust`, `simple-icons:scala`, `simple-icons:springboot`, `simple-icons:svelte`, `simple-icons:swift`, `simple-icons:symfony`, `simple-icons:vite`, `simple-icons:zig`) and filled with the brand colors (the standard icon grey for black logos). Licensed under [CC0 1.0 Universal](https://github.com/simple-icons/simple-icons/blob/develop/LICENSE.md).
+
 ## Project Lombok
 
 `java/lombok/lombok-1.18.48-openidea.3.jar` contains Project Lombok v1.18.48 with the Equinox
@@ -262,7 +268,7 @@ END OF TERMS AND CONDITIONS
 
 The Solarized palettes in `src/styles/tokens.css` are adapted from
 [Ethan Schoonover’s Solarized](https://github.com/altercation/solarized/tree/62f656a02f93c5190a8753159e34b385588d5ff3).
-See [theme sources and mapping](docs/themes.md). MIT license:
+MIT license:
 
 ```text
 Copyright (c) 2011 Ethan Schoonover
@@ -290,7 +296,11 @@ THE SOFTWARE.
 
 The One palettes and semantic syntax mapping in `src/styles/tokens.css` are
 adapted from GitHub’s Atom One syntax and UI themes.
-Source revisions are listed in [theme sources and mapping](docs/themes.md).
+Source revisions:
+[one-light-syntax d845790](https://github.com/atom/one-light-syntax/tree/d84579027410c576086dfca14d934c4bd74b0438),
+[one-dark-syntax 9c96f44](https://github.com/atom/one-dark-syntax/tree/9c96f4454362267ac45322063e193ccf9d2debb1),
+[one-light-ui a27bce3](https://github.com/atom/one-light-ui/tree/a27bce35088ecd323e44f5c2510bcf2d4e9efcf8),
+[one-dark-ui 18c2143](https://github.com/atom/one-dark-ui/tree/18c2143d41e17b337fff6dc7024562c4d999be17).
 Both syntax themes use the following MIT notice:
 
 ```text

crates/ide-agent/src/acp/mod.rs

@@ -164,6 +164,11 @@ impl Negotiated {
         self.capabilities.pointer(&format!("/promptCapabilities/{name}")).and_then(Value::as_bool) == Some(true)
     }
 
+    /// `mcpCapabilities.<name>` (`http`, `sse`).
+    pub fn mcp(&self, name: &str) -> bool {
+        self.capabilities.pointer(&format!("/mcpCapabilities/{name}")).and_then(Value::as_bool) == Some(true)
+    }
+
     /// `sessionCapabilities.<name>` (`fork`, `resume`, `close`, `list`, `delete`).
     pub fn session(&self, name: &str) -> bool {
         self.capabilities.pointer(&format!("/sessionCapabilities/{name}")).is_some_and(|v| !v.is_null())
@@ -173,6 +178,17 @@ impl Negotiated {
     pub fn meta(&self, pointer: &str) -> Option<&Value> {
         self.capabilities.get("_meta")?.pointer(pointer)
     }
+
+    /// First authentication method the agent can run over ACP (`type` absent or `"agent"`).
+    pub fn agent_auth_method(&self) -> Option<&str> {
+        self.auth_methods.iter().find_map(|m| {
+            let kind = m.get("type").and_then(Value::as_str).unwrap_or("agent");
+            (kind == "agent" && m.pointer("/_meta/terminal-auth").is_none())
+                .then(|| m.get("id").and_then(Value::as_str))
+                .flatten()
+                .filter(|id| !id.is_empty())
+        })
+    }
 }
 
 /// The client side of one agent connection: wraps the task's [`Handler`] and, once

crates/ide-agent/src/acp/tests.rs

@@ -135,6 +135,36 @@ fn the_shape_decides_the_version_not_the_number() {
     assert_eq!((n.generation, n.load_session(), n.session("fork")), (2, false, false));
 }
 
+#[test]
+fn picks_non_terminal_agent_auth_method() {
+    let v1 = Negotiated::from_initialize(&json!({
+        "protocolVersion": 1,
+        "authMethods": [
+            { "id": "cli_login", "_meta": { "terminal-auth": { "command": "copilot", "args": ["login"] } } },
+            { "id": "terminal_login", "type": "terminal", "args": ["login"] },
+            { "id": "api_key", "type": "env_var" },
+            { "id": "github_oauth", "name": "GitHub OAuth" }
+        ]
+    }));
+    assert_eq!(v1.agent_auth_method(), Some("github_oauth"));
+
+    let v2 = Negotiated::from_initialize(&json!({
+        "protocolVersion": 2,
+        "info": { "name": "x", "version": "1" },
+        "authMethods": [
+            { "type": "terminal", "methodId": "cli", "name": "CLI", "args": ["login"] },
+            { "type": "agent", "methodId": "oauth", "name": "OAuth" }
+        ]
+    }));
+    assert_eq!(v2.agent_auth_method(), Some("oauth"));
+
+    let terminal_only = Negotiated::from_initialize(&json!({
+        "protocolVersion": 1,
+        "authMethods": [{ "id": "cli", "type": "terminal", "args": ["login"] }]
+    }));
+    assert_eq!(terminal_only.agent_auth_method(), None);
+}
+
 #[test]
 fn meta_and_auth_methods_pass_through() {
     // The native shims advertise their extensions in `agentCapabilities._meta`.

crates/ide-agent/src/external.rs

@@ -0,0 +1,325 @@
+//! Sessions the user started outside OpenIDEA (a terminal, another editor, the CLI):
+//! scanned so they can be listed and imported as tasks instead of re-explained (#312).
+//!
+//! Only the native providers keep transcripts on disk in a readable form: Claude Code
+//! (`<config>/projects/*/<id>.jsonl`, see `native::claude::history`) and Codex
+//! (`<home>/.codex/sessions/**`, rollout files with a `session_meta` line).
+
+use super::native::claude::history;
+use serde::Serialize;
+use specta::Type;
+use std::io::BufRead;
+use std::path::{Path, PathBuf};
+
+/// A session on this machine that no task holds yet.
+#[derive(Clone, Debug, Serialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct ExternalSession {
+    /// The [`crate::AgentProvider`] id that owns it (`claude`, `codex`).
+    pub provider: String,
+    /// The id resuming it names (`--resume`, `thread/resume`).
+    pub session_id: String,
+    pub title: String,
+    /// Where it ran, when the transcript names one.
+    pub cwd: Option<String>,
+    /// File modification time, ms since the epoch.
+    pub updated_ms: f64,
+}
+
+/// Modification time of `path` in ms, else 0.
+fn mtime(path: &Path) -> f64 {
+    path.metadata()
+        .and_then(|m| m.modified())
+        .ok()
+        .and_then(|t| t.duration_since(std::time::UNIX_EPOCH).ok())
+        .map(|d| d.as_millis() as f64)
+        .unwrap_or(0.0)
+}
+
+/// Short display text: collapsed whitespace, truncated to `MAX_TITLE` chars.
+fn short(text: &str) -> String {
+    const MAX_TITLE: usize = 80;
+    let flat: String = text.split_whitespace().collect::<Vec<_>>().join(" ");
+    if flat.chars().count() <= MAX_TITLE {
+        flat
+    } else {
+        format!("{}…", flat.chars().take(MAX_TITLE - 1).collect::<String>())
+    }
+}
+
+/// The text of a Claude Code transcript entry's message, when it carries prose.
+fn message_text(e: &serde_json::Value) -> Option<String> {
+    match e.pointer("/message/content") {
+        Some(serde_json::Value::String(s)) => Some(s.clone()),
+        Some(serde_json::Value::Array(blocks)) => {
+            let text: Vec<&str> = blocks
+                .iter()
+                .filter(|b| b.get("type").and_then(serde_json::Value::as_str) == Some("text"))
+                .filter_map(|b| b.get("text").and_then(serde_json::Value::as_str))
+                .collect();
+            (!text.is_empty()).then(|| text.join("\n"))
+        }
+        _ => None,
+    }
+}
+
+/// Whether a session that ran in `cwd` belongs to the project at `root` (in it or below it).
+fn in_project(cwd: Option<&str>, root: &Path) -> bool {
+    cwd.is_some_and(|cwd| Path::new(cwd).starts_with(root))
+}
+
+/// Claude Code transcripts of the project at `root`: `<config>/projects/<escaped cwd>/<id>.jsonl`.
+/// Only the folders named after `root` or a folder below it are read, so other projects'
+/// transcripts (often gigabytes) are never opened.
+pub fn claude_sessions(config_dir: &Path, root: &Path) -> Vec<ExternalSession> {
+    let mut out = Vec::new();
+    let projects = config_dir.join("projects");
+    let escaped = history::escape(root);
+    let dirs: Vec<PathBuf> = std::fs::read_dir(&projects)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .filter(|d| {
+            let name = d.file_name().to_string_lossy().into_owned();
+            name == escaped || name.starts_with(&format!("{escaped}-"))
+        })
+        .map(|d| d.path())
+        .collect();
+    for dir in dirs {
+        let files: Vec<PathBuf> = std::fs::read_dir(&dir)
+            .into_iter()
+            .flatten()
+            .flatten()
+            .map(|d| d.path())
+            .filter(|p| p.extension().is_some_and(|e| e == "jsonl"))
+            .collect();
+        for path in files {
+            let id = path.file_stem().and_then(|s| s.to_str()).unwrap_or_default().to_owned();
+            if id.is_empty() {
+                continue;
+            }
+            let entries = history::read(&path).unwrap_or_default();
+            if entries.is_empty() {
+                continue;
+            }
+            let title = history::title(&entries)
+                .or_else(|| entries.iter().filter(|e| history::is_turn_start(e)).filter_map(message_text).next())
+                .map(|t| short(&t))
+                .unwrap_or_else(|| format!("Claude Code session {}", &id[..id.len().min(8)]));
+            let cwd = entries
+                .iter()
+                .filter_map(|e| e.get("cwd").and_then(serde_json::Value::as_str))
+                .next()
+                .map(str::to_owned);
+            // Escaping is lossy (`a/b-c` and `a/b/c` share a folder): the transcript decides.
+            if !in_project(cwd.as_deref(), root) {
+                continue;
+            }
+            out.push(ExternalSession {
+                provider: "claude".to_owned(),
+                session_id: id,
+                title,
+                cwd,
+                updated_ms: mtime(&path),
+            });
+        }
+    }
+    out
+}
+
+/// The `session_meta` line of a Codex rollout file: `(id, cwd)`, across shapes.
+fn codex_meta(line: &serde_json::Value) -> Option<(String, Option<String>)> {
+    let payload =
+        line.get("payload").filter(|p| p.get("type").and_then(serde_json::Value::as_str) == Some("session_meta"));
+    let inner = payload.and_then(|p| p.get("payload")).or_else(|| {
+        line.get("type").and_then(serde_json::Value::as_str).filter(|t| *t == "session_meta").and(Some(line))
+    })?;
+    let id = inner.get("id").and_then(serde_json::Value::as_str)?.to_owned();
+    let cwd = inner.get("cwd").and_then(serde_json::Value::as_str).map(str::to_owned);
+    Some((id, cwd))
+}
+
+/// A prose line of a Codex rollout file (a user message), across shapes.
+fn codex_user_text(line: &serde_json::Value) -> Option<String> {
+    let payload = line.get("payload")?;
+    let ty = payload.get("type").and_then(serde_json::Value::as_str)?;
+    if !(ty == "user_message" || ty == "userMessage" || ty == "event_msg") {
+        return None;
+    }
+    let inner = payload.get("payload").unwrap_or(&serde_json::Value::Null);
+    for v in [payload, inner] {
+        if let Some(s) = v.get("message").and_then(serde_json::Value::as_str) {
+            return Some(s.to_owned());
+        }
+        if let Some(s) = v.get("text").and_then(serde_json::Value::as_str) {
+            return Some(s.to_owned());
+        }
+    }
+    None
+}
+
+/// One rollout file's session, or `None` when it names no `session_meta`.
+fn codex_file(path: &Path) -> Option<ExternalSession> {
+    let file = std::fs::File::open(path).ok()?;
+    let mut id: Option<(String, Option<String>)> = None;
+    let mut title: Option<String> = None;
+    // `session_meta` is first, but cap the scan: giant rollouts must not stall listing.
+    for line in std::io::BufReader::new(file).lines().take(400) {
+        let Ok(line) = line else { break };
+        let Ok(v) = serde_json::from_str::<serde_json::Value>(&line) else { continue };
+        if id.is_none()
+            && let Some(meta) = codex_meta(&v)
+        {
+            id = Some(meta);
+        }
+        if title.is_none()
+            && let Some(t) = codex_user_text(&v)
+        {
+            title = Some(short(&t));
+        }
+        if id.is_some() && title.is_some() {
+            break;
+        }
+    }
+    let (session_id, cwd) = id?;
+    Some(ExternalSession {
+        provider: "codex".to_owned(),
+        title: title.unwrap_or_else(|| format!("Codex session {}", &session_id[..session_id.len().min(8)])),
+        session_id,
+        cwd,
+        updated_ms: mtime(path),
+    })
+}
+
+/// Collects `*.jsonl` below `dir`, up to 4 levels (`sessions/YYYY/MM/DD/<rollout>`).
+fn rollout_files(dir: &Path, depth: usize, out: &mut Vec<PathBuf>) {
+    if depth == 0 {
+        return;
+    }
+    for entry in std::fs::read_dir(dir).into_iter().flatten().flatten() {
+        let path = entry.path();
+        if path.is_dir() {
+            rollout_files(&path, depth - 1, out);
+        } else if path.extension().is_some_and(|e| e == "jsonl") {
+            out.push(path);
+        }
+    }
+}
+
+/// Codex sessions of the project at `root`: `<home>/.codex/sessions/**`.
+pub fn codex_sessions(codex_home: &Path, root: &Path) -> Vec<ExternalSession> {
+    let mut files = Vec::new();
+    rollout_files(&codex_home.join("sessions"), 4, &mut files);
+    files.iter().filter_map(|p| codex_file(p)).filter(|s| in_project(s.cwd.as_deref(), root)).collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+    use std::io::Write;
+
+    fn write(path: &Path, lines: &[serde_json::Value]) {
+        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+        let mut f = std::fs::File::create(path).unwrap();
+        for line in lines {
+            writeln!(f, "{line}").unwrap();
+        }
+    }
+
+    fn claude_user(uuid: &str, text: &str) -> serde_json::Value {
+        json!({"type": "user", "uuid": uuid, "parentUuid": null,
+            "message": {"role": "user", "content": text}, "cwd": "/work/app"})
+    }
+
+    #[test]
+    fn lists_claude_transcripts_with_titles() {
+        let tmp = tempfile::tempdir().unwrap();
+        write(
+            &tmp.path().join("projects/-work-app/abc123.jsonl"),
+            &[
+                claude_user("u1", "fix the login bug"),
+                json!({"type": "assistant", "uuid": "a1", "parentUuid": "u1",
+                    "message": {"role": "assistant", "content": []}}),
+                json!({"type": "ai-title", "aiTitle": "Login fix"}),
+            ],
+        );
+        write(&tmp.path().join("projects/-work-app/empty.jsonl"), &[]);
+        let sessions = claude_sessions(tmp.path(), Path::new("/work/app"));
+        assert_eq!(sessions.len(), 1);
+        let s = &sessions[0];
+        assert_eq!((s.provider.as_str(), s.session_id.as_str()), ("claude", "abc123"));
+        assert_eq!(s.title, "Login fix");
+        assert_eq!(s.cwd.as_deref(), Some("/work/app"));
+        assert!(s.updated_ms > 0.0);
+    }
+
+    #[test]
+    fn claude_title_falls_back_to_the_first_prompt() {
+        let tmp = tempfile::tempdir().unwrap();
+        write(&tmp.path().join("projects/-work-app/def456.jsonl"), &[claude_user("u1", "hello there")]);
+        let sessions = claude_sessions(tmp.path(), Path::new("/work/app"));
+        assert_eq!(sessions.len(), 1);
+        assert_eq!(sessions[0].title, "hello there");
+    }
+
+    #[test]
+    fn lists_codex_rollouts_with_meta() {
+        let tmp = tempfile::tempdir().unwrap();
+        write(
+            &tmp.path().join("sessions/2026/01/02/rollout-01.jsonl"),
+            &[
+                json!({"timestamp": "t", "payload": {"type": "session_meta",
+                    "payload": {"id": "thread-1", "cwd": "/work/app"}}}),
+                json!({"timestamp": "t", "payload": {"type": "user_message",
+                    "payload": {"message": "add tests"}}}),
+            ],
+        );
+        write(&tmp.path().join("sessions/notes.jsonl"), &[json!({"nope": true})]);
+        let sessions = codex_sessions(tmp.path(), Path::new("/work"));
+        assert_eq!(sessions.len(), 1);
+        let s = &sessions[0];
+        assert_eq!((s.provider.as_str(), s.session_id.as_str()), ("codex", "thread-1"));
+        assert_eq!(s.title, "add tests");
+        assert_eq!(s.cwd.as_deref(), Some("/work/app"));
+    }
+
+    #[test]
+    fn missing_directories_list_nothing() {
+        let tmp = tempfile::tempdir().unwrap();
+        assert!(claude_sessions(&tmp.path().join("nope"), Path::new("/work")).is_empty());
+        assert!(codex_sessions(&tmp.path().join("nope"), Path::new("/work")).is_empty());
+    }
+
+    #[test]
+    fn only_sessions_of_the_project_are_listed() {
+        let tmp = tempfile::tempdir().unwrap();
+        let user = |cwd: &str| {
+            json!({"type": "user", "uuid": "u1", "parentUuid": null,
+                "message": {"role": "user", "content": "hi"}, "cwd": cwd})
+        };
+        write(&tmp.path().join("projects/-work-app/in-root.jsonl"), &[user("/work/app")]);
+        write(&tmp.path().join("projects/-work-app-web/below.jsonl"), &[user("/work/app/web")]);
+        // `/work/app-old` escapes like a folder below `/work/app`; its transcript says otherwise.
+        write(&tmp.path().join("projects/-work-app-old/sibling.jsonl"), &[user("/work/app-old")]);
+        write(&tmp.path().join("projects/-other/elsewhere.jsonl"), &[user("/other")]);
+        let mut ids: Vec<String> =
+            claude_sessions(tmp.path(), Path::new("/work/app")).into_iter().map(|s| s.session_id).collect();
+        ids.sort();
+        assert_eq!(ids, ["below", "in-root"]);
+
+        let rollout = |name: &str, cwd: &str| {
+            write(
+                &tmp.path().join(format!("codex/sessions/2026/01/02/{name}.jsonl")),
+                &[json!({"payload": {"type": "session_meta", "payload": {"id": name, "cwd": cwd}}})],
+            )
+        };
+        rollout("mine", "/work/app/api");
+        rollout("theirs", "/other");
+        let codex: Vec<String> = codex_sessions(&tmp.path().join("codex"), Path::new("/work/app"))
+            .into_iter()
+            .map(|s| s.session_id)
+            .collect();
+        assert_eq!(codex, ["mine"]);
+    }
+}

crates/ide-agent/src/lib.rs

@@ -10,6 +10,8 @@
 mod acp;
 mod config;
 mod conversation;
+mod external;
+pub mod mcp;
 mod model;
 mod native;
 mod provider;
@@ -18,6 +20,7 @@ mod skills;
 mod timeline;
 mod worktree;
 
+pub use external::ExternalSession;
 pub use model::*;
 
 use conversation::{Conversation, SavedSubagent, Session};
@@ -91,6 +94,9 @@ type Connector = Arc<
         + Sync,
 >;
 
+/// Returns the configured MCP servers (User and Workspace) for this project.
+pub type McpServersFn = dyn Fn() -> Vec<McpServer> + Send + Sync;
+
 struct Shared {
     paths: AgentPaths,
     runtime: tokio::runtime::Handle,
@@ -104,6 +110,7 @@ struct Shared {
     command_fetches: Mutex<HashMap<String, tokio::sync::watch::Receiver<bool>>>,
     /// [`IDLE_RELEASE`], in milliseconds (shorter in tests).
     idle_release_ms: AtomicU64,
+    mcp_servers_hook: RwLock<Option<Arc<McpServersFn>>>,
 }
 
 /// What an agent offered in its last session, for the New Task page.
@@ -131,6 +138,13 @@ impl Shared {
         }
     }
 
+    fn mcp_servers_for_session(&self, provider: &str, init: &acp::Negotiated) -> Vec<Value> {
+        let mut servers = mcp_servers_for(init.mcp_stdio(), &self.paths.project_root);
+        let configured = self.mcp_servers_hook.read().as_ref().map(|hook| hook()).unwrap_or_default();
+        servers.extend(mcp::acp_mcp_servers(&configured, provider, init));
+        servers
+    }
+
     fn known_config(&self, provider: &str) -> Vec<AgentConfigOption> {
         let mut config = self.known.lock().get(provider).map(|k| k.config.clone()).unwrap_or_default();
         // Model-specific options are offered separately, never as provider-wide defaults.
@@ -163,16 +177,25 @@ impl Shared {
                     let shared = self.clone();
                     // Keep the lookup alive if a composer unmounts while it is waiting.
                     self.runtime.spawn(async move {
-                        if let Ok((commands, options)) =
+                        if let Ok(found) =
                             native::claude::discover(spec.clone(), shared.paths.project_root.clone()).await
                         {
-                            let commands = config::commands_of(&json!({ "availableCommands": commands }), &spec.id);
-                            let options = config::options_of(&json!({ "configOptions": options }));
+                            let commands =
+                                config::commands_of(&json!({ "availableCommands": found.commands }), &spec.id);
+                            let options = config::options_of(&json!({ "configOptions": found.options }));
+                            let levels: Vec<_> = found
+                                .efforts
+                                .into_iter()
+                                .map(|(model, o)| {
+                                    let options = o.map(|o| config::options_of(&json!({ "configOptions": [o] })));
+                                    (model, options.unwrap_or_default())
+                                })
+                                .collect();
                             let _ = tokio::task::spawn_blocking(move || {
                                 // Notifies subscribers itself when the discovery
                                 // changed the cached config; unchanged results
                                 // stay silent.
-                                shared.remember_discovered(&spec.id, &options, &commands);
+                                shared.remember_discovered(&spec.id, &options, &commands, &levels);
                             })
                             .await;
                         }
@@ -193,6 +216,18 @@ impl Shared {
         self.known.lock().get(provider).is_some_and(|k| !k.config.is_empty())
     }
 
+    /// Whether the thinking levels of every model the agent offers are known (#1686).
+    fn knows_all_levels(&self, provider: &str) -> bool {
+        let cache = self.known.lock();
+        let Some(known) = cache.get(provider) else { return false };
+        known
+            .config
+            .iter()
+            .filter(|o| o.category.as_deref() == Some("model"))
+            .flat_map(|o| &o.values)
+            .all(|v| known.thought_levels.contains_key(&v.value))
+    }
+
     fn root_key(&self) -> String {
         self.paths.project_root.to_string_lossy().into_owned()
     }
@@ -205,11 +240,19 @@ impl Shared {
         commands: Option<&[AgentCommand]>,
         model: Option<&str>,
     ) {
-        self.remember_inner(provider, config, commands, model, false);
+        self.remember_inner(provider, config, commands, model, &[], false);
     }
 
-    fn remember_discovered(&self, provider: &str, config: &[AgentConfigOption], commands: &[AgentCommand]) {
-        self.remember_inner(provider, Some(config), Some(commands), model_of(config).as_deref(), true);
+    /// `levels`: each model's thinking-level options, so a new task offers them for any model
+    /// it picks (#1686). A session's report for a model wins over these.
+    fn remember_discovered(
+        &self,
+        provider: &str,
+        config: &[AgentConfigOption],
+        commands: &[AgentCommand],
+        levels: &[(String, Vec<AgentConfigOption>)],
+    ) {
+        self.remember_inner(provider, Some(config), Some(commands), model_of(config).as_deref(), levels, true);
     }
 
     fn remember_inner(
@@ -218,12 +261,19 @@ impl Shared {
         config: Option<&[AgentConfigOption]>,
         commands: Option<&[AgentCommand]>,
         model: Option<&str>,
+        discovered_levels: &[(String, Vec<AgentConfigOption>)],
         discovered: bool,
     ) {
         // Keep the update and its disk write ordered; a session report wins over discovery.
         let mut cache = self.known.lock();
         let known = cache.entry(provider.to_owned()).or_default();
         let mut changed = false;
+        for (model, levels) in discovered_levels {
+            if !known.thought_levels.contains_key(model) {
+                known.thought_levels.insert(model.clone(), levels.clone());
+                changed = true;
+            }
+        }
         if let Some(c) = config.filter(|_| !discovered || known.config.is_empty()) {
             if let Some(model) = model {
                 let levels: Vec<_> =
@@ -277,6 +327,9 @@ struct TaskFile {
     /// In the project's own checkout: files already changed when the task started.
     #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
     before: BTreeMap<String, worktree::Stamp>,
+    /// The folder (in the task store) with copies of the `before` files, for rolling back.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    saved: Option<String>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     subagents: Vec<SavedSubagent>,
     /// Turns to drop from the session once it is loaded (a fork of an earlier point).
@@ -293,6 +346,7 @@ struct TaskState {
     conversation: Conversation,
     wanted: Vec<AgentConfigChoice>,
     before: Arc<BTreeMap<String, worktree::Stamp>>,
+    saved: Option<String>,
     pending_rollback: u32,
     /// The user named the task; see `TaskFile::title_renamed`.
     title_renamed: bool,
@@ -315,7 +369,7 @@ struct Live {
     embedded: bool,
     /// `session/load`: the process can be stopped between turns and the session reloaded.
     resumable: bool,
-    mcp_stdio: bool,
+    init: acp::Negotiated,
 }
 
 struct Task {
@@ -345,6 +399,8 @@ struct Task {
     /// Settings already sent this session (`(option, value)`), so a refusal is not retried.
     config_sent: Mutex<HashSet<(String, String)>>,
     dirty: Mutex<BTreeSet<(Session, usize)>>,
+    /// How much of each session's streaming message was last sent, so the next flush sends the rest.
+    streamed: Mutex<HashMap<Session, Sent>>,
     flush_scheduled: AtomicBool,
     stderr: Mutex<VecDeque<String>>,
     /// Set by `delete`; held while saving.
@@ -383,6 +439,7 @@ impl AgentManager {
             probes: Mutex::new(HashMap::new()),
             command_fetches: Mutex::new(HashMap::new()),
             idle_release_ms: AtomicU64::new(IDLE_RELEASE.as_millis() as u64),
+            mcp_servers_hook: RwLock::new(None),
         });
         let mut tasks = HashMap::new();
         for file in std::fs::read_dir(&shared.paths.store_dir).into_iter().flatten().flatten() {
@@ -423,8 +480,11 @@ impl AgentManager {
     /// The agents (custom ones re-read), whether each is installed, and what they offered last time.
     pub fn providers(&self) -> Vec<AgentProvider> {
         let specs = provider::load(self.shared.paths.custom_agents_dir.as_deref());
+        let in_use: std::collections::HashSet<String> =
+            self.tasks.read().values().map(|t| t.state.lock().task.provider.clone()).collect();
         let list = specs
             .iter()
+            .filter(|p| !provider::is_unlisted(p) || in_use.contains(&p.id))
             .map(|p| {
                 let mut info = provider::describe(p);
                 info.config = self.shared.known_config(&p.id);
@@ -470,6 +530,11 @@ impl AgentManager {
         self.shared.emit(AgentEvent::Providers);
     }
 
+    /// Provides the user and workspace MCP servers configured in settings.
+    pub fn set_mcp_servers_hook(&self, hook: Box<McpServersFn>) {
+        *self.shared.mcp_servers_hook.write() = Some(Arc::from(hook));
+    }
+
     /// The slash commands to complete for `provider`, in `task`'s directory or (without one)
     /// in the project: what the agent offered last time there, unadvertised builtins,
     /// and, for Claude Code, skills and custom commands on disk it has not listed.
@@ -486,7 +551,7 @@ impl AgentManager {
         // merged without duplicating what `availableCommands` or the disk offer.
         let mut offered = offered;
         if task.is_none()
-            && (offered.is_empty() || !self.shared.has_config(&provider))
+            && (offered.is_empty() || !self.shared.has_config(&provider) || !self.shared.knows_all_levels(&provider))
             && let Some(spec) = self.shared.spec(&provider).filter(|s| s.driver == provider::Driver::Claude)
         {
             self.shared.fetch_settings(spec).await;
@@ -522,6 +587,93 @@ impl AgentManager {
         Ok(timeline.entries.clone())
     }
 
+    /// Session ids the tasks already hold (native drivers reuse the CLI's own id).
+    fn imported_session_ids(&self) -> HashSet<String> {
+        self.tasks.read().values().filter_map(|t| t.state.lock().session_id.clone()).collect()
+    }
+
+    /// Sessions of this project on this machine that no task holds yet, newest first. Reads
+    /// transcripts from disk: call it off the UI and command threads.
+    pub fn external_sessions(&self) -> Vec<ExternalSession> {
+        let mut out = Vec::new();
+        let root = self.shared.paths.project_root.clone();
+        if let Some(spec) = self.shared.spec("claude")
+            && let Some(dir) = native::claude::cli::config_dir(&spec.env)
+        {
+            out.extend(external::claude_sessions(&dir, &root));
+        }
+        let home = self.shared.paths.home_dir.clone().or_else(home_dir);
+        if let Some(home) = home {
+            out.extend(external::codex_sessions(&home.join(".codex"), &root));
+        }
+        let known = self.imported_session_ids();
+        out.retain(|s| !known.contains(&s.session_id));
+        out.sort_by(|a, b| b.updated_ms.total_cmp(&a.updated_ms));
+        out.truncate(50);
+        out
+    }
+
+    /// Imports an external session as a task: its first turn loads and replays it (#312).
+    pub fn import_session(&self, provider: &str, session_id: &str) -> IdeResult<AgentTask> {
+        if !matches!(provider, "claude" | "codex") {
+            return Err(IdeError::invalid(format!("cannot import {provider} sessions")));
+        }
+        let spec = self.shared.spec(provider).ok_or_else(|| IdeError::invalid(format!("unknown agent {provider}")))?;
+        if self.imported_session_ids().contains(session_id) {
+            return Err(IdeError::invalid("that session is already a task"));
+        }
+        let found = self
+            .external_sessions()
+            .into_iter()
+            .find(|s| s.provider == provider && s.session_id == session_id)
+            .ok_or_else(|| IdeError::not_found(format!("unknown {provider} session {session_id}")))?;
+        let root = self.shared.paths.project_root.clone();
+        let cwd = found.cwd.map(PathBuf::from).filter(|p| p.is_absolute()).unwrap_or_else(|| root.clone());
+        let config = self.shared.known_config(&spec.id);
+        let now = now_ms();
+        let id = uuid::Uuid::new_v4().simple().to_string();
+        let task = AgentTask {
+            project_root: Some(IpcPath(root)),
+            id,
+            title: found.title,
+            provider: spec.id.clone(),
+            model: model_of(&config),
+            status: AgentStatus::Ready,
+            isolation: Isolation::Local,
+            cwd: IpcPath(cwd),
+            branch: None,
+            base: None,
+            base_commit: None,
+            error: None,
+            created_ms: now,
+            updated_ms: now,
+            config,
+            commands: self.shared.known_commands(&spec.id),
+            usage: None,
+            queue: Vec::new(),
+            capabilities: self.shared.probes.lock().get(&spec.id).map(|p| p.capabilities).unwrap_or_default(),
+            resets_ms: None,
+            retry: None,
+            background: Box::default(),
+        };
+        let file = TaskFile {
+            task: task.clone(),
+            session_id: Some(session_id.to_owned()),
+            entries: Vec::new(),
+            wanted: Vec::new(),
+            before: BTreeMap::new(),
+            saved: None,
+            subagents: Vec::new(),
+            pending_rollback: 0,
+            title_renamed: true,
+        };
+        let handle = Task::restore(file, self.shared.clone());
+        self.tasks.write().insert(task.id.clone(), handle.clone());
+        handle.emit_task();
+        handle.persist();
+        Ok(task)
+    }
+
     /// Creates the task (and its worktree) and sends `req.prompt` as its first message.
     pub async fn create(&self, req: NewAgentTask) -> IdeResult<AgentTask> {
         let spec = self
@@ -574,9 +726,24 @@ impl AgentManager {
             }));
         }
         let now = now_ms();
+        let id = uuid::Uuid::new_v4().simple().to_string();
+        // Copies of the files the user had changed already, for rolling back the task's changes to them.
+        let saved = if before.is_empty() {
+            None
+        } else {
+            let name = format!("{id}.before");
+            let (dir, at, files) = (self.shared.paths.store_dir.join(&name), cwd.clone(), before.clone());
+            match blocking(move || worktree::save_before(&at, &files, &dir)).await {
+                Ok(saved) => saved.then_some(name),
+                Err(e) => {
+                    tracing::warn!("saving the changed files of agent task {id}: {e}");
+                    None
+                }
+            }
+        };
         let task = AgentTask {
             project_root,
-            id: uuid::Uuid::new_v4().simple().to_string(),
+            id,
             title,
             provider: spec.id.clone(),
             model: model_of(&config),
@@ -604,6 +771,7 @@ impl AgentManager {
             entries: Vec::new(),
             wanted: req.config,
             before,
+            saved,
             subagents: Vec::new(),
             pending_rollback: 0,
             title_renamed: false,
@@ -771,10 +939,16 @@ impl AgentManager {
             return Err(IdeError::invalid("this agent can't copy a conversation from there"));
         }
         let cwd = source.state.lock().task.cwd.0.clone();
+        let provider_id = source.state.lock().task.provider.clone();
+        let mcp_servers = source.shared.mcp_servers_for_session(&provider_id, &live.init);
         let cwd_s = dunce::canonicalize(&cwd).unwrap_or(cwd).to_string_lossy().into_owned();
         let reply: Value = live
             .peer
-            .request("session/fork", json!({ "sessionId": live.session, "cwd": cwd_s, "mcpServers": mcp_servers_for(live.mcp_stdio, &source.shared.paths.project_root) }), None)
+            .request(
+                "session/fork",
+                json!({ "sessionId": live.session, "cwd": cwd_s, "mcpServers": mcp_servers }),
+                None,
+            )
             .await
             .map_err(|e| IdeError::internal(source.describe(e)))?;
         let session = reply
@@ -808,6 +982,7 @@ impl AgentManager {
                 entries,
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
+                saved: s.saved.clone(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: total - keep,
                 title_renamed: s.title_renamed,
@@ -852,6 +1027,7 @@ impl AgentManager {
                 s.task.updated_ms = now_ms();
                 first
             };
+            task.streamed.lock().clear();
             task.persist();
             self.shared.emit(AgentEvent::Truncated { task: id.to_owned(), length: 0 });
             task.emit_task();
@@ -877,6 +1053,7 @@ impl AgentManager {
             s.task.updated_ms = now_ms();
             first
         };
+        task.streamed.lock().clear();
         task.persist();
         self.shared.emit(AgentEvent::Truncated { task: id.to_owned(), length: cut as u32 });
         task.emit_task();
@@ -1057,6 +1234,17 @@ impl AgentManager {
         };
         // A copy of the task (a fork) may work in the same worktree.
         let shared = self.tasks.read().values().any(|t| t.id != id && t.state.lock().task.cwd.0 == cwd);
+        self.tasks.write().remove(id);
+        *task.deleted.lock() = true;
+        let _ = std::fs::remove_file(self.shared.paths.store_dir.join(format!("{id}.json")));
+        let saved = task.state.lock().saved.clone();
+        if let Some(saved) = saved
+            && !self.tasks.read().values().any(|t| t.state.lock().saved.as_ref() == Some(&saved))
+        {
+            let _ = std::fs::remove_dir_all(self.shared.paths.store_dir.join(saved));
+        }
+        // The list drops the task now; removing a large worktree's folder can take a while.
+        self.shared.emit(AgentEvent::Removed { id: id.to_owned() });
         if remove_worktree && !shared && isolation == Isolation::Worktree && cwd.exists() {
             // On Windows the agent's processes lock the folder (their working directory,
             // open files) until they have exited.
@@ -1066,10 +1254,6 @@ impl AgentManager {
             let worktrees = self.shared.paths.worktrees_dir.clone();
             blocking(move || worktree::remove(&root, &worktrees, &cwd)).await?;
         }
-        self.tasks.write().remove(id);
-        *task.deleted.lock() = true;
-        let _ = std::fs::remove_file(self.shared.paths.store_dir.join(format!("{id}.json")));
-        self.shared.emit(AgentEvent::Removed { id: id.to_owned() });
         Ok(())
     }
 
@@ -1087,6 +1271,41 @@ impl AgentManager {
         blocking(move || worktree::file_at(&cwd, &path, &base)).await
     }
 
+    /// Rollback: puts the task's changed files among `rel_paths` (all with `None`) back as they
+    /// were when it started (files the user had changed then, as the user left them).
+    pub async fn rollback_changes(&self, id: &str, rel_paths: Option<Vec<String>>) -> IdeResult<()> {
+        let task = self.task(id)?;
+        if task.state.lock().busy {
+            return Err(IdeError::invalid("the agent is working: stop it before rolling back its changes"));
+        }
+        let (cwd, base) = task.cwd_and_base();
+        let (before, saved) = {
+            let s = task.state.lock();
+            (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)))
+        };
+        let restamped = blocking(move || {
+            let changes = worktree::without_untouched(worktree::changes(&cwd, &base)?, &before);
+            let mut restamped = Vec::new();
+            for change in changes.iter().filter(|c| rel_paths.as_ref().is_none_or(|p| p.contains(&c.rel_path))) {
+                worktree::restore(&cwd, &base, change, &before, saved.as_deref())?;
+                // Back to the user's own edits: not a change of the task any more.
+                if before.contains_key(&change.rel_path) {
+                    restamped.push((change.rel_path.clone(), worktree::stamp(&change.path.0)));
+                }
+            }
+            Ok(restamped)
+        })
+        .await?;
+        if !restamped.is_empty() {
+            let mut s = task.state.lock();
+            let mut before = (*s.before).clone();
+            before.extend(restamped);
+            s.before = Arc::new(before);
+        }
+        task.persist();
+        Ok(())
+    }
+
     /// Stops every agent (project closed).
     pub fn shutdown(&self) {
         for task in self.tasks.read().values() {
@@ -1112,6 +1331,7 @@ impl Task {
                 conversation,
                 wanted: file.wanted,
                 before: Arc::new(file.before),
+                saved: file.saved,
                 pending_rollback: file.pending_rollback,
                 title_renamed: file.title_renamed,
                 busy: false,
@@ -1129,6 +1349,7 @@ impl Task {
             idle_epoch: AtomicU64::new(0),
             config_sent: Mutex::new(HashSet::new()),
             dirty: Mutex::new(BTreeSet::new()),
+            streamed: Mutex::new(HashMap::new()),
             flush_scheduled: AtomicBool::new(false),
             stderr: Mutex::new(VecDeque::new()),
             deleted: Mutex::new(false),
@@ -1223,6 +1444,7 @@ impl Task {
                 entries: s.conversation.main.entries.clone(),
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
+                saved: s.saved.clone(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: s.pending_rollback,
                 title_renamed: s.title_renamed,
@@ -1250,11 +1472,12 @@ impl Task {
         let indices = std::mem::take(&mut *self.dirty.lock());
         let events: Vec<AgentEvent> = {
             let s = self.state.lock();
+            let mut streamed = self.streamed.lock();
             indices
                 .into_iter()
                 .filter_map(|(subagent, i)| {
-                    let entry = s.conversation.timeline(&subagent)?.entries.get(i)?.clone();
-                    Some(AgentEvent::Entry { task: self.id.clone(), subagent, index: i as u32, entry })
+                    let entry = s.conversation.timeline(&subagent)?.entries.get(i)?;
+                    Some(entry_event(&self.id, &mut streamed, subagent, i, entry))
                 })
                 .collect()
         };
@@ -1490,6 +1713,30 @@ impl Task {
         })
     }
 
+    /// Runs `method` and, on an auth error, tries the agent's own ACP `authenticate` once before retrying.
+    async fn request_with_auth(
+        &self,
+        peer: &acp::Conn,
+        init: &acp::Negotiated,
+        tried_auth: &mut bool,
+        method: &str,
+        params: Value,
+    ) -> Result<Value, RpcError> {
+        let first = peer.request(method, params.clone(), None).await;
+        if !*tried_auth
+            && let Err(RpcError::Server { code, ref message, .. }) = first
+            && acp::auth_required(code, message)
+            && let Some(method_id) = init.agent_auth_method()
+        {
+            *tried_auth = true;
+            match peer.request::<_, Value>("authenticate", json!({ "methodId": method_id }), None).await {
+                Ok(_) => return peer.request(method, params, None).await,
+                Err(e) => tracing::debug!(task = %self.id, method_id, error = %e, "agent authenticate failed"),
+            }
+        }
+        first
+    }
+
     async fn ensure_session(self: &Arc<Self>) -> Result<Live, String> {
         let _guard = self.connecting.lock().await;
         if let Some(live) = self.live.lock().clone()
@@ -1527,16 +1774,17 @@ impl Task {
         let init = peer.initialize(&client_info()).await.map_err(|e| self.describe(e))?;
         let sign_in_message = spec.sign_in_message(&init.auth_methods);
         let can_load = init.load_session();
-        let mcp_stdio = init.mcp_stdio();
         let (capabilities, embedded) = capabilities_of(&init);
+        let mcp_servers = self.shared.mcp_servers_for_session(&provider_id, &init);
         // Agents that compare canonical paths fail in a symlinked directory (macOS `/tmp`).
         let cwd_s = dunce::canonicalize(&cwd).unwrap_or(cwd).to_string_lossy().into_owned();
 
+        let mut tried_auth = false;
         let mut session = None;
         if let (Some(id), true) = (saved, can_load) {
             self.replaying.store(true, Ordering::Release);
-            let loaded: Result<Value, RpcError> =
-                peer.request("session/load", json!({ "sessionId": id, "cwd": cwd_s, "mcpServers": mcp_servers_for(mcp_stdio, &self.shared.paths.project_root) }), None).await;
+            let params = json!({ "sessionId": &id, "cwd": &cwd_s, "mcpServers": &mcp_servers });
+            let loaded = self.request_with_auth(&peer, &init, &mut tried_auth, "session/load", params).await;
             tokio::time::sleep(REPLAY_GRACE).await;
             self.replaying.store(false, Ordering::Release);
             match loaded {
@@ -1548,12 +1796,9 @@ impl Task {
         let (session_id, result) = match session {
             Some(s) => s,
             None => {
-                let v: Value = peer
-                    .request(
-                        "session/new",
-                        json!({ "cwd": cwd_s, "mcpServers": mcp_servers_for(mcp_stdio, &self.shared.paths.project_root) }),
-                        None,
-                    )
+                let params = json!({ "cwd": &cwd_s, "mcpServers": &mcp_servers });
+                let v = self
+                    .request_with_auth(&peer, &init, &mut tried_auth, "session/new", params)
                     .await
                     .map_err(|e| self.sign_in_error(&e, Some(&sign_in_message)).unwrap_or_else(|| self.describe(e)))?;
                 let id = v.get("sessionId").and_then(Value::as_str).ok_or("the agent returned no session")?.to_owned();
@@ -1645,7 +1890,7 @@ impl Task {
         self.persist();
         self.emit_task();
         let live =
-            Live { sign_in_message, peer, session: session_id, capabilities, embedded, resumable: can_load, mcp_stdio };
+            Live { sign_in_message, peer, session: session_id, capabilities, embedded, resumable: can_load, init };
         *self.live.lock() = Some(live.clone());
         Ok(live)
     }
@@ -1716,7 +1961,7 @@ impl Task {
                     format!("The agent process exited:\n{}", tail.join("\n"))
                 }
             }
-            RpcError::Server { message, .. } => message,
+            RpcError::Server { message, data, .. } => with_details(message, data.as_ref()),
             e => e.to_string(),
         }
     }
@@ -2174,6 +2419,24 @@ fn usage_limit(e: &RpcError) -> Option<Option<f64>> {
         .then_some(None)
 }
 
+/// An error's message with the detail ACP agents put in `data` (`{"details": …}` or a string):
+/// generic codes such as "Internal error" say nothing without it.
+fn with_details(message: String, data: Option<&Value>) -> String {
+    let details = match data {
+        Some(Value::String(text)) => text.as_str(),
+        Some(data) => data.get("details").and_then(Value::as_str).unwrap_or_default(),
+        None => "",
+    }
+    .trim();
+    if details.is_empty() || message.contains(details) {
+        message
+    } else if message.trim().is_empty() {
+        details.to_owned()
+    } else {
+        format!("{message}: {details}")
+    }
+}
+
 fn client_info() -> Value {
     json!({ "name": "OpenIDEA", "version": env!("CARGO_PKG_VERSION") })
 }
@@ -2281,6 +2544,11 @@ fn now_ms() -> f64 {
     std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map_or(0.0, |d| d.as_millis() as f64)
 }
 
+/// The user's home, for tools that keep state there (Codex sessions).
+fn home_dir() -> Option<PathBuf> {
+    std::env::var_os("HOME").or_else(|| std::env::var_os("USERPROFILE")).map(PathBuf::from)
+}
+
 fn write_file(path: &Path, bytes: &[u8]) -> Result<(), String> {
     if let Some(dir) = path.parent() {
         std::fs::create_dir_all(dir).map_err(|e| e.to_string())?;
@@ -2316,3 +2584,77 @@ fn stdio_mcp_servers(executable: Option<&std::path::Path>, supported: bool, root
     let command = ide_mcp::stdio_command(executable, root);
     vec![json!({ "name": "OpenIDEA", "command": command[0], "args": command[1..], "env": [] })]
 }
+
+/// What was sent of a streaming message: its first `bytes` (`utf16` UTF-16 units), which
+/// ended with `tail`. A message only grows while it streams, so its tail tells a message
+/// that went on from one that was replaced without comparing (or keeping) all of it.
+struct Sent {
+    index: usize,
+    bytes: usize,
+    utf16: usize,
+    tail: String,
+}
+
+const SENT_TAIL: usize = 64;
+
+impl Sent {
+    fn new(index: usize, text: &str) -> Self {
+        Self::after(index, text, 0, 0)
+    }
+
+    /// `text` as sent, of which the first `bytes` (`utf16` units) were sent before.
+    fn after(index: usize, text: &str, bytes: usize, utf16: usize) -> Self {
+        let mut start = text.len().saturating_sub(SENT_TAIL);
+        while !text.is_char_boundary(start) {
+            start -= 1;
+        }
+        let utf16 = utf16 + text[bytes..].encode_utf16().count();
+        Self { index, bytes: text.len(), utf16, tail: text[start..].to_owned() }
+    }
+
+    /// Whether `text` at `index` is this message, gone on.
+    fn extended_by(&self, index: usize, text: &str) -> bool {
+        self.index == index
+            && text.len() > self.bytes
+            && text.is_char_boundary(self.bytes)
+            && text[..self.bytes].ends_with(&self.tail)
+    }
+}
+
+/// The event that brings the UI's copy of entry `i` up to date: only the new text when
+/// it extends the message last sent for the session, else the whole entry.
+fn entry_event(
+    task: &str,
+    streamed: &mut HashMap<Session, Sent>,
+    subagent: Session,
+    i: usize,
+    entry: &AgentEntry,
+) -> AgentEvent {
+    let text = match entry {
+        AgentEntry::Agent { text } | AgentEntry::Thought { text } => Some(text),
+        _ => None,
+    };
+    let Some(text) = text else {
+        if streamed.get(&subagent).is_some_and(|sent| sent.index == i) {
+            streamed.remove(&subagent);
+        }
+        return AgentEvent::Entry { task: task.to_owned(), subagent, index: i as u32, entry: entry.clone() };
+    };
+    match streamed.get(&subagent).filter(|sent| sent.extended_by(i, text)) {
+        Some(sent) => {
+            let (bytes, from) = (sent.bytes, sent.utf16);
+            streamed.insert(subagent.clone(), Sent::after(i, text, bytes, from));
+            AgentEvent::Append {
+                task: task.to_owned(),
+                subagent,
+                index: i as u32,
+                from: from as u32,
+                text: text[bytes..].to_owned(),
+            }
+        }
+        None => {
+            streamed.insert(subagent.clone(), Sent::new(i, text));
+            AgentEvent::Entry { task: task.to_owned(), subagent, index: i as u32, entry: entry.clone() }
+        }
+    }
+}

crates/ide-agent/src/mcp.rs

@@ -0,0 +1,507 @@
+//! Model Context Protocol (MCP) server configurations stored in OpenIDEA's own settings
+//! (global `settings.toml` and project `.openidea/settings.toml`), passed to ACP agents in
+//! `session/new`, `session/load`, and `session/fork`, plus one-way import from `.mcp.json` /
+//! `.vscode/mcp.json`.
+
+use crate::acp::Negotiated;
+use crate::{AgentMcpServer, McpKeyValue, McpScope, McpServer, McpServerInput, McpTransport};
+use serde_json::{Value, json};
+use std::collections::{BTreeMap, HashSet};
+use std::path::Path;
+
+/// Stable ID for a server in a given scope (`"user::<name>"` or `"workspace::<name>"`).
+pub fn server_id(scope: McpScope, name: &str) -> String {
+    let prefix = match scope {
+        McpScope::User => "user",
+        McpScope::Workspace => "workspace",
+    };
+    format!("{prefix}::{name}")
+}
+
+/// Parses a server ID (`"user::<name>"` or `"workspace::<name>"`).
+pub fn parse_server_id(id: &str) -> Option<(McpScope, &str)> {
+    let (prefix, name) = id.split_once("::")?;
+    if name.is_empty() {
+        return None;
+    }
+    match prefix {
+        "user" => Some((McpScope::User, name)),
+        "workspace" => Some((McpScope::Workspace, name)),
+        _ => None,
+    }
+}
+
+/// Converts the User (`settings.toml`) and Workspace (`.openidea/settings.toml`) MCP server maps
+/// into the ordered list displayed in Settings › Agents › MCP Servers.
+pub fn servers_from_settings(
+    user: &BTreeMap<String, AgentMcpServer>,
+    workspace: &BTreeMap<String, AgentMcpServer>,
+) -> Vec<McpServer> {
+    user.iter()
+        .map(|(name, cfg)| to_mcp_server(McpScope::User, name, cfg))
+        .chain(workspace.iter().map(|(name, cfg)| to_mcp_server(McpScope::Workspace, name, cfg)))
+        .collect()
+}
+
+fn to_mcp_server(scope: McpScope, name: &str, cfg: &AgentMcpServer) -> McpServer {
+    McpServer {
+        id: server_id(scope, name),
+        name: name.to_owned(),
+        scope,
+        transport: cfg.transport,
+        enabled: cfg.enabled,
+        command: cfg.command.clone(),
+        args: cfg.args.clone(),
+        env: cfg.env.iter().map(|(k, v)| McpKeyValue { name: k.clone(), value: v.clone() }).collect(),
+        url: cfg.url.clone(),
+        headers: cfg.headers.iter().map(|(k, v)| McpKeyValue { name: k.clone(), value: v.clone() }).collect(),
+        agents: cfg.agents.clone(),
+    }
+}
+
+fn normalize_provider(id: &str) -> &str {
+    id.strip_suffix("-acp").unwrap_or(id)
+}
+
+fn matches_agent(agents: &[String], provider: &str) -> bool {
+    if agents.is_empty() {
+        return true;
+    }
+    let target = normalize_provider(provider);
+    agents.iter().any(|a| {
+        let trimmed = a.trim();
+        trimmed == provider || normalize_provider(trimmed) == target
+    })
+}
+
+/// Builds the ACP `mcpServers` array for `session/new`, `session/load`, and `session/fork`.
+/// Workspace entries take precedence over User entries with the same name.
+pub(crate) fn acp_mcp_servers(all: &[McpServer], provider: &str, init: &Negotiated) -> Vec<Value> {
+    let supports_stdio = init.mcp_stdio();
+    let supports_http = init.mcp("http");
+    let supports_sse = init.mcp("sse");
+    let mut seen = HashSet::new();
+    let mut servers = Vec::new();
+
+    let ordered =
+        all.iter().filter(|s| s.scope == McpScope::Workspace).chain(all.iter().filter(|s| s.scope == McpScope::User));
+
+    for srv in ordered {
+        if !srv.enabled || !matches_agent(&srv.agents, provider) || !seen.insert(srv.name.clone()) {
+            continue;
+        }
+        match srv.transport {
+            McpTransport::Stdio if supports_stdio => {
+                let Some(cmd) = srv.command.as_deref().filter(|c| !c.trim().is_empty()) else {
+                    continue;
+                };
+                let env: Vec<Value> = srv.env.iter().map(|kv| json!({ "name": kv.name, "value": kv.value })).collect();
+                servers.push(json!({
+                    "name": srv.name,
+                    "command": cmd,
+                    "args": srv.args,
+                    "env": env,
+                }));
+            }
+            McpTransport::Http if supports_http => {
+                let Some(url) = srv.url.as_deref().filter(|u| !u.trim().is_empty()) else {
+                    continue;
+                };
+                let headers: Vec<Value> =
+                    srv.headers.iter().map(|kv| json!({ "name": kv.name, "value": kv.value })).collect();
+                servers.push(json!({
+                    "type": "http",
+                    "name": srv.name,
+                    "url": url,
+                    "headers": headers,
+                }));
+            }
+            McpTransport::Sse if supports_sse => {
+                let Some(url) = srv.url.as_deref().filter(|u| !u.trim().is_empty()) else {
+                    continue;
+                };
+                let headers: Vec<Value> =
+                    srv.headers.iter().map(|kv| json!({ "name": kv.name, "value": kv.value })).collect();
+                servers.push(json!({
+                    "type": "sse",
+                    "name": srv.name,
+                    "url": url,
+                    "headers": headers,
+                }));
+            }
+            _ => {}
+        }
+    }
+
+    servers
+}
+
+/// Applies a create or update operation to the User / Workspace MCP server maps.
+pub fn apply_save(
+    user: &mut BTreeMap<String, AgentMcpServer>,
+    workspace: &mut BTreeMap<String, AgentMcpServer>,
+    has_workspace: bool,
+    input: McpServerInput,
+) -> Result<(), String> {
+    let name = input.name.trim();
+    if name.is_empty() {
+        return Err("Server name is required".into());
+    }
+    if input.scope == McpScope::Workspace && !has_workspace {
+        return Err("Open a project to configure workspace MCP servers".into());
+    }
+    let cfg = match input.transport {
+        McpTransport::Stdio => {
+            let cmd = input.command.as_deref().map(str::trim).unwrap_or_default();
+            if cmd.is_empty() {
+                return Err("Command is required for stdio MCP servers".into());
+            }
+            let env = input
+                .env
+                .into_iter()
+                .filter_map(|kv| {
+                    let k = kv.name.trim();
+                    (!k.is_empty()).then(|| (k.to_owned(), kv.value))
+                })
+                .collect();
+            AgentMcpServer {
+                transport: McpTransport::Stdio,
+                enabled: input.enabled,
+                command: Some(cmd.to_owned()),
+                args: input.args,
+                env,
+                url: None,
+                headers: BTreeMap::new(),
+                agents: normalize_agents_list(input.agents),
+            }
+        }
+        McpTransport::Http | McpTransport::Sse => {
+            let url = input.url.as_deref().map(str::trim).unwrap_or_default();
+            if url.is_empty() {
+                return Err("URL is required for HTTP/SSE MCP servers".into());
+            }
+            let headers = input
+                .headers
+                .into_iter()
+                .filter_map(|kv| {
+                    let k = kv.name.trim();
+                    (!k.is_empty()).then(|| (k.to_owned(), kv.value))
+                })
+                .collect();
+            AgentMcpServer {
+                transport: input.transport,
+                enabled: input.enabled,
+                command: None,
+                args: Vec::new(),
+                env: BTreeMap::new(),
+                url: Some(url.to_owned()),
+                headers,
+                agents: normalize_agents_list(input.agents),
+            }
+        }
+    };
+
+    if let Some(prev_id) = input.id.as_deref()
+        && let Some((prev_scope, prev_name)) = parse_server_id(prev_id)
+        && (prev_scope != input.scope || prev_name != name)
+    {
+        match prev_scope {
+            McpScope::User => {
+                user.remove(prev_name);
+            }
+            McpScope::Workspace => {
+                workspace.remove(prev_name);
+            }
+        }
+    }
+
+    match input.scope {
+        McpScope::User => {
+            user.insert(name.to_owned(), cfg);
+        }
+        McpScope::Workspace => {
+            workspace.insert(name.to_owned(), cfg);
+        }
+    }
+    Ok(())
+}
+
+/// Enables or disables a User or Workspace MCP server by ID.
+pub fn apply_set_enabled(
+    user: &mut BTreeMap<String, AgentMcpServer>,
+    workspace: &mut BTreeMap<String, AgentMcpServer>,
+    id: &str,
+    enabled: bool,
+) -> Result<McpScope, String> {
+    let (scope, name) = parse_server_id(id).ok_or_else(|| format!("MCP server `{id}` not found"))?;
+    let map = match scope {
+        McpScope::User => user,
+        McpScope::Workspace => workspace,
+    };
+    let srv = map.get_mut(name).ok_or_else(|| format!("MCP server `{name}` not found"))?;
+    srv.enabled = enabled;
+    Ok(scope)
+}
+
+/// Removes a User or Workspace MCP server by ID.
+pub fn apply_remove(
+    user: &mut BTreeMap<String, AgentMcpServer>,
+    workspace: &mut BTreeMap<String, AgentMcpServer>,
+    id: &str,
+) -> Result<McpScope, String> {
+    let (scope, name) = parse_server_id(id).ok_or_else(|| format!("MCP server `{id}` not found"))?;
+    let map = match scope {
+        McpScope::User => user,
+        McpScope::Workspace => workspace,
+    };
+    if map.remove(name).is_none() {
+        return Err(format!("MCP server `{name}` not found"));
+    }
+    Ok(scope)
+}
+
+/// Imports MCP servers from `<workspace_root>/.mcp.json` and `<workspace_root>/.vscode/mcp.json`
+/// into `workspace` without modifying the external files. Returns the number of newly added servers.
+pub fn apply_import(workspace: &mut BTreeMap<String, AgentMcpServer>, workspace_root: &Path) -> usize {
+    let mut added = 0;
+    for rel in [".mcp.json", ".vscode/mcp.json"] {
+        let path = workspace_root.join(rel);
+        for (name, srv) in read_external_file(&path) {
+            if let std::collections::btree_map::Entry::Vacant(e) = workspace.entry(name) {
+                e.insert(srv);
+                added += 1;
+            }
+        }
+    }
+    added
+}
+
+fn normalize_agents_list(agents: Vec<String>) -> Vec<String> {
+    let mut out = Vec::new();
+    for a in agents {
+        let trimmed = a.trim();
+        if !trimmed.is_empty() && !out.iter().any(|existing: &String| existing == trimmed) {
+            out.push(trimmed.to_owned());
+        }
+    }
+    out
+}
+
+fn read_external_file(path: &Path) -> BTreeMap<String, AgentMcpServer> {
+    let Ok(bytes) = std::fs::read(path) else {
+        return BTreeMap::new();
+    };
+    let Ok(root) = serde_json::from_slice::<Value>(&bytes) else {
+        return BTreeMap::new();
+    };
+    let Some(servers_obj) = root.get("mcpServers").or_else(|| root.get("servers")).and_then(Value::as_object) else {
+        return BTreeMap::new();
+    };
+
+    let mut out = BTreeMap::new();
+    for (name, def) in servers_obj {
+        let name = name.trim();
+        let Some(obj) = def.as_object().filter(|_| !name.is_empty()) else {
+            continue;
+        };
+        let disabled = obj.get("disabled").and_then(Value::as_bool).unwrap_or(false)
+            || obj.get("enabled").and_then(Value::as_bool) == Some(false);
+        let type_str = obj.get("type").and_then(Value::as_str).unwrap_or_default().to_ascii_lowercase();
+        let url = obj
+            .get("url")
+            .or_else(|| obj.get("serverUrl"))
+            .and_then(Value::as_str)
+            .map(str::trim)
+            .filter(|s| !s.is_empty())
+            .map(str::to_owned);
+        let command =
+            obj.get("command").and_then(Value::as_str).map(str::trim).filter(|s| !s.is_empty()).map(str::to_owned);
+
+        let transport = match type_str.as_str() {
+            "sse" => McpTransport::Sse,
+            "http" | "streamable-http" | "streamable_http" => McpTransport::Http,
+            "stdio" | "local" => McpTransport::Stdio,
+            _ if url.is_some() && command.is_none() => McpTransport::Http,
+            _ => McpTransport::Stdio,
+        };
+
+        match transport {
+            McpTransport::Stdio if command.is_none() => continue,
+            McpTransport::Http | McpTransport::Sse if url.is_none() => continue,
+            _ => {}
+        }
+
+        let args = obj
+            .get("args")
+            .and_then(Value::as_array)
+            .map(|arr| arr.iter().filter_map(|v| v.as_str().map(str::to_owned)).collect())
+            .unwrap_or_default();
+
+        out.insert(
+            name.to_owned(),
+            AgentMcpServer {
+                transport,
+                enabled: !disabled,
+                command,
+                args,
+                env: parse_key_values_map(obj.get("env")),
+                url,
+                headers: parse_key_values_map(obj.get("headers")),
+                agents: Vec::new(),
+            },
+        );
+    }
+    out
+}
+
+fn parse_key_values_map(val: Option<&Value>) -> BTreeMap<String, String> {
+    match val {
+        Some(Value::Object(map)) => map
+            .iter()
+            .filter_map(|(k, v)| {
+                let s = match v {
+                    Value::String(s) => s.clone(),
+                    Value::Number(n) => n.to_string(),
+                    Value::Bool(b) => b.to_string(),
+                    _ => return None,
+                };
+                Some((k.clone(), s))
+            })
+            .collect(),
+        Some(Value::Array(arr)) => arr
+            .iter()
+            .filter_map(|item| {
+                let obj = item.as_object()?;
+                let name = obj.get("name")?.as_str()?.to_owned();
+                let value = obj.get("value")?.as_str()?.to_owned();
+                Some((name, value))
+            })
+            .collect(),
+        _ => BTreeMap::new(),
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn crud_and_acp_filtering_by_scope_agent_and_transport() {
+        let mut user = BTreeMap::new();
+        let mut workspace = BTreeMap::new();
+
+        apply_save(
+            &mut user,
+            &mut workspace,
+            true,
+            McpServerInput {
+                id: None,
+                name: "shared".into(),
+                scope: McpScope::User,
+                transport: McpTransport::Stdio,
+                enabled: true,
+                command: Some("npx".into()),
+                args: vec!["-y".into(), "user-pkg".into()],
+                env: vec![McpKeyValue { name: "TOKEN".into(), value: "u1".into() }],
+                url: None,
+                headers: Vec::new(),
+                agents: Vec::new(),
+            },
+        )
+        .unwrap();
+
+        apply_save(
+            &mut user,
+            &mut workspace,
+            true,
+            McpServerInput {
+                id: None,
+                name: "shared".into(),
+                scope: McpScope::Workspace,
+                transport: McpTransport::Stdio,
+                enabled: true,
+                command: Some("npx".into()),
+                args: vec!["-y".into(), "workspace-pkg".into()],
+                env: Vec::new(),
+                url: None,
+                headers: Vec::new(),
+                agents: Vec::new(),
+            },
+        )
+        .unwrap();
+
+        apply_save(
+            &mut user,
+            &mut workspace,
+            true,
+            McpServerInput {
+                id: None,
+                name: "claude-http".into(),
+                scope: McpScope::User,
+                transport: McpTransport::Http,
+                enabled: true,
+                command: None,
+                args: Vec::new(),
+                env: Vec::new(),
+                url: Some("https://example.com/mcp".into()),
+                headers: vec![McpKeyValue { name: "Authorization".into(), value: "Bearer secret".into() }],
+                agents: vec!["claude".into()],
+            },
+        )
+        .unwrap();
+
+        let list = servers_from_settings(&user, &workspace);
+        assert_eq!(list.len(), 3);
+
+        // Negotiated with HTTP support: `claude` gets workspace `shared` + `claude-http`; `codex` only gets `shared`.
+        let init_http = Negotiated::from_initialize(&json!({
+            "agentCapabilities": { "mcpCapabilities": { "http": true, "sse": false } }
+        }));
+        let claude_servers = acp_mcp_servers(&list, "claude-acp", &init_http);
+        assert_eq!(claude_servers.len(), 2);
+        assert_eq!(claude_servers[0]["name"], "shared");
+        assert_eq!(claude_servers[0]["args"], json!(["-y", "workspace-pkg"]));
+        assert_eq!(claude_servers[1]["name"], "claude-http");
+        assert_eq!(claude_servers[1]["type"], "http");
+
+        let codex_servers = acp_mcp_servers(&list, "codex", &init_http);
+        assert_eq!(codex_servers.len(), 1);
+        assert_eq!(codex_servers[0]["name"], "shared");
+
+        // Disable workspace `shared` and remove user `claude-http`.
+        apply_set_enabled(&mut user, &mut workspace, "workspace::shared", false).unwrap();
+        apply_remove(&mut user, &mut workspace, "user::claude-http").unwrap();
+        let list = servers_from_settings(&user, &workspace);
+        let after = acp_mcp_servers(&list, "claude", &init_http);
+        assert_eq!(after.len(), 1);
+        assert_eq!(after[0]["args"], json!(["-y", "user-pkg"]));
+    }
+
+    #[test]
+    fn imports_from_mcp_json_and_vscode_mcp_json_without_modifying_them() {
+        let tmp = tempfile::tempdir().unwrap();
+        let mcp_json = tmp.path().join(".mcp.json");
+        let vscode_dir = tmp.path().join(".vscode");
+        std::fs::create_dir_all(&vscode_dir).unwrap();
+        let vscode_mcp = vscode_dir.join("mcp.json");
+
+        let raw_mcp = r#"{"mcpServers":{"sqlite":{"command":"uvx","args":["mcp-server-sqlite"]}}}"#;
+        let raw_vscode = r#"{"servers":{"remote":{"type":"http","url":"https://mcp.example.com"}}}"#;
+        std::fs::write(&mcp_json, raw_mcp).unwrap();
+        std::fs::write(&vscode_mcp, raw_vscode).unwrap();
+
+        let mut workspace = BTreeMap::new();
+        let added = apply_import(&mut workspace, tmp.path());
+        assert_eq!(added, 2);
+        assert_eq!(workspace["sqlite"].command.as_deref(), Some("uvx"));
+        assert_eq!(workspace["remote"].transport, McpTransport::Http);
+        assert_eq!(workspace["remote"].url.as_deref(), Some("https://mcp.example.com"));
+
+        // Re-importing does not duplicate or overwrite existing entries, and leaves files untouched.
+        workspace.get_mut("sqlite").unwrap().enabled = false;
+        assert_eq!(apply_import(&mut workspace, tmp.path()), 0);
+        assert!(!workspace["sqlite"].enabled);
+        assert_eq!(std::fs::read_to_string(&mcp_json).unwrap(), raw_mcp);
+        assert_eq!(std::fs::read_to_string(&vscode_mcp).unwrap(), raw_vscode);
+    }
+}

crates/ide-agent/src/model.rs

@@ -518,6 +518,15 @@ pub enum AgentEvent {
         index: u32,
         entry: AgentEntry,
     },
+    /// Text was appended to entry `index` (an agent message or a thought): it read the first
+    /// `from` UTF-16 units of its text when the previous event for it was sent.
+    Append {
+        task: String,
+        subagent: Option<String>,
+        index: u32,
+        from: u32,
+        text: String,
+    },
     /// An agent reported the usage limits of its account (shared by every task of `provider`).
     Limits {
         provider: String,
@@ -526,3 +535,70 @@ pub enum AgentEvent {
     /// The installed or configured agent providers changed.
     Providers,
 }
+
+pub use ide_core::settings::{AgentMcpServer, McpTransport};
+
+/// Where an MCP server configuration is stored (`settings.toml` vs `.openidea/settings.toml`).
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum McpScope {
+    User,
+    Workspace,
+}
+
+/// A named environment variable or HTTP header for an MCP server.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct McpKeyValue {
+    pub name: String,
+    pub value: String,
+}
+
+/// One configured Model Context Protocol (MCP) server.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct McpServer {
+    pub id: String,
+    pub name: String,
+    pub scope: McpScope,
+    pub transport: McpTransport,
+    pub enabled: bool,
+    pub command: Option<String>,
+    pub args: Vec<String>,
+    pub env: Vec<McpKeyValue>,
+    pub url: Option<String>,
+    pub headers: Vec<McpKeyValue>,
+    /// Agent provider ids this server is enabled for; empty means enabled for all agents.
+    #[serde(default)]
+    pub agents: Vec<String>,
+}
+
+/// Payload for creating or updating a user or workspace MCP server.
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct McpServerInput {
+    #[serde(default)]
+    pub id: Option<String>,
+    pub name: String,
+    pub scope: McpScope,
+    pub transport: McpTransport,
+    #[serde(default = "default_true")]
+    pub enabled: bool,
+    #[serde(default)]
+    pub command: Option<String>,
+    #[serde(default)]
+    pub args: Vec<String>,
+    #[serde(default)]
+    pub env: Vec<McpKeyValue>,
+    #[serde(default)]
+    pub url: Option<String>,
+    #[serde(default)]
+    pub headers: Vec<McpKeyValue>,
+    /// Agent provider ids this server is enabled for; empty means enabled for all agents.
+    #[serde(default)]
+    pub agents: Vec<String>,
+}
+
+fn default_true() -> bool {
+    true
+}

crates/ide-agent/src/native/claude/cli.rs

@@ -135,7 +135,7 @@ impl Cli for Process {
 }
 
 /// Claude Code's configuration directory (`CLAUDE_CONFIG_DIR`, else `~/.claude`).
-pub(super) fn config_dir(env: &[(String, String)]) -> Option<PathBuf> {
+pub(crate) fn config_dir(env: &[(String, String)]) -> Option<PathBuf> {
     let set = env
         .iter()
         .find(|(k, _)| k == "CLAUDE_CONFIG_DIR")

crates/ide-agent/src/native/claude/history.rs

@@ -31,11 +31,11 @@ pub(super) fn transcript(config_dir: &Path, cwd: &Path, id: &str) -> PathBuf {
 }
 
 /// The project directory name Claude Code uses for `cwd`.
-pub(super) fn escape(cwd: &Path) -> String {
+pub(crate) fn escape(cwd: &Path) -> String {
     cwd.to_string_lossy().chars().map(|c| if c.is_ascii_alphanumeric() { c } else { '-' }).collect()
 }
 
-pub(super) fn read(path: &Path) -> std::io::Result<Vec<Value>> {
+pub(crate) fn read(path: &Path) -> std::io::Result<Vec<Value>> {
     let text = std::fs::read_to_string(path)?;
     Ok(text.lines().filter_map(|l| serde_json::from_str(l).ok()).collect())
 }
@@ -111,7 +111,7 @@ fn block_ids<'a>(e: &'a Value, ty: &'a str, key: &'a str) -> impl Iterator<Item
 
 /// Whether `e` is a message that started a turn: the user's own, not a tool result, a
 /// steer, or text Claude Code added.
-pub(super) fn is_turn_start(e: &Value) -> bool {
+pub(crate) fn is_turn_start(e: &Value) -> bool {
     if kind(e) != "user" || e.get("isMeta").and_then(Value::as_bool) == Some(true) {
         return false;
     }
@@ -149,7 +149,7 @@ pub(super) fn cut(chain: &[&Value], turns: usize) -> Result<Option<String>, Stri
 }
 
 /// The newest title Claude Code gave the session.
-pub(super) fn title(entries: &[Value]) -> Option<String> {
+pub(crate) fn title(entries: &[Value]) -> Option<String> {
     entries
         .iter()
         .rev()

crates/ide-agent/src/native/claude/mod.rs

@@ -7,8 +7,8 @@
 //! <id>.json`): loading that session, from this connection or a fresh one, starts it that
 //! way.
 
-mod cli;
-mod history;
+pub(crate) mod cli;
+pub(crate) mod history;
 mod settings;
 mod tools;
 mod translate;
@@ -69,9 +69,17 @@ pub(crate) fn connect(
     Ok(super::serve(shim, client))
 }
 
+/// What discovery found: ACP `availableCommands`, `configOptions` for the configured model,
+/// and each model's effort option by model value (`None`: none).
+pub(crate) struct Discovered {
+    pub commands: Vec<Value>,
+    pub options: Value,
+    pub efforts: Vec<(String, Option<Value>)>,
+}
+
 /// Discover the slash commands and the model, mode and effort options without a prompt,
 /// ACP session, or pending session file.
-pub(crate) async fn discover(spec: ProviderSpec, cwd: PathBuf) -> Result<(Vec<Value>, Value), String> {
+pub(crate) async fn discover(spec: ProviderSpec, cwd: PathBuf) -> Result<Discovered, String> {
     tokio::time::timeout(Duration::from_secs(5), async move {
         let spec = tokio::task::spawn_blocking(move || (spec.resolve_for_launch(&cwd), cwd));
         let (spec, cwd) = spec.await.map_err(|e| e.to_string())?;
@@ -100,7 +108,11 @@ pub(crate) async fn discover(spec: ProviderSpec, cwd: PathBuf) -> Result<(Vec<Va
         .flatten()
         .unwrap_or_default();
         let settings = Settings::from_cli(&init, &applied);
-        Ok((settings.commands.clone(), settings.options()))
+        Ok(Discovered {
+            commands: settings.commands.clone(),
+            options: settings.options(),
+            efforts: settings.efforts_by_model(),
+        })
     })
     .await
     .map_err(|_| "Claude Code command discovery timed out".to_owned())?

crates/ide-agent/src/native/claude/settings.rs

@@ -132,19 +132,18 @@ impl Settings {
                 }).collect::<Vec<_>>(),
             }));
         }
-        let efforts = self.current_model().map(|m| m.efforts.as_slice()).unwrap_or_default();
-        if !efforts.is_empty() {
-            let mut values = vec![json!({ "value": "default", "name": "Default" })];
-            values.extend(efforts.iter().map(|e| json!({ "value": e, "name": capitalize(e) })));
-            let current = if efforts.contains(&self.effort) { self.effort.as_str() } else { "default" };
-            out.push(json!({
-                "id": EFFORT, "name": "Effort", "category": "thought_level", "type": "select",
-                "currentValue": current, "options": values,
-            }));
+        if let Some(effort) = self.current_model().and_then(|m| effort_option(m, &self.effort)) {
+            out.push(effort);
         }
         Value::Array(out)
     }
 
+    /// Each model's effort option by model value (`None`: it has no effort levels): what a new
+    /// task offers once that model is picked, before any session has run it.
+    pub fn efforts_by_model(&self) -> Vec<(String, Option<Value>)> {
+        self.models.iter().map(|m| (m.value.clone(), effort_option(m, &self.effort))).collect()
+    }
+
     pub fn valid(&self, option: &str, value: &str) -> bool {
         self.options()
             .as_array()
@@ -156,6 +155,20 @@ impl Settings {
     }
 }
 
+/// `model`'s effort option, with `effort` selected when the model offers it; `None` without efforts.
+fn effort_option(model: &Model, effort: &str) -> Option<Value> {
+    if model.efforts.is_empty() {
+        return None;
+    }
+    let mut values = vec![json!({ "value": "default", "name": "Default" })];
+    values.extend(model.efforts.iter().map(|e| json!({ "value": e, "name": capitalize(e) })));
+    let current = if model.efforts.iter().any(|e| e == effort) { effort } else { "default" };
+    Some(json!({
+        "id": EFFORT, "name": "Effort", "category": "thought_level", "type": "select",
+        "currentValue": current, "options": values,
+    }))
+}
+
 /// Slash commands as ACP `availableCommands`, without those that need Claude Code's terminal.
 pub(super) fn commands(list: Option<&Value>, terminal_only: &[String]) -> Vec<Value> {
     list.and_then(Value::as_array)
@@ -231,4 +244,20 @@ mod tests {
         let cmds = commands(init().get("commands"), &["doctor".into()]);
         assert_eq!(cmds, vec![json!({"name": "review", "description": "Review", "input": {"hint": "[pr]"}})]);
     }
+
+    #[test]
+    fn every_model_offers_its_own_efforts() {
+        let s = Settings::from_cli(&init(), &json!({"applied": {"model": "claude-sonnet-5-5", "effort": "high"}}));
+        let efforts = s.efforts_by_model();
+        let values = |model: &str| {
+            let (_, o) = efforts.iter().find(|(m, _)| m == model).unwrap();
+            let o = o.as_ref().unwrap();
+            let values: Vec<_> = o["options"].as_array().unwrap().iter().map(|v| v["value"].clone()).collect();
+            (values, o["currentValue"].clone())
+        };
+        assert_eq!(values("default"), (vec![json!("default"), json!("low"), json!("high")], json!("high")));
+        // The configured effort only where the model offers it.
+        assert_eq!(values("opus"), (vec![json!("default"), json!("low"), json!("max")], json!("default")));
+        assert!(efforts.contains(&("claude-haiku-4-5".into(), None)), "no effort option without levels");
+    }
 }

crates/ide-agent/src/provider.rs

@@ -59,11 +59,14 @@ const BUILTIN: &[(&str, &str, Driver, &[&str], &str)] = &[
     ("cursor", "Cursor", Driver::Acp, &["cursor-agent", "acp"], "Run `cursor-agent login` in a terminal."),
     ("opencode", "OpenCode", Driver::Acp, &["opencode", "acp"], "Run `opencode auth login` in a terminal."),
     ("qwen", "Qwen Code", Driver::Acp, &["qwen", "--experimental-acp"], "Run `qwen` in a terminal and sign in."),
+    ("qoder", "Qoder", Driver::Acp, &["qodercli", "--acp"], "Run `qodercli login` in a terminal."),
+    ("qodercn", "Qoder CN", Driver::Acp, &["qoderclicn", "--acp"], "Run `qoderclicn login` in a terminal."),
     ("kimi", "Kimi CLI", Driver::Acp, &["kimi", "acp"], "Run `kimi` in a terminal and sign in."),
     ("goose", "Goose", Driver::Acp, &["goose", "acp"], "Run `goose configure` in a terminal."),
     ("auggie", "Auggie", Driver::Acp, &["auggie", "--acp"], "Run `auggie login` in a terminal."),
     ("kiro", "Kiro", Driver::Acp, &["kiro-cli", "acp"], "Run `kiro-cli login` in a terminal."),
     ("vibe", "Mistral Vibe", Driver::Acp, &["vibe-acp"], "Run `vibe` in a terminal and sign in."),
+    ("omp", "OMP", Driver::Acp, &["omp", "acp"], "Run `omp` in a terminal and sign in."),
 ];
 
 fn builtins() -> Vec<ProviderSpec> {
@@ -184,6 +187,14 @@ pub(crate) fn builtin_spec(id: &str) -> Option<ProviderSpec> {
     builtins().into_iter().find(|s| s.id == id)
 }
 
+/// The ACP adapters of Claude Code and Codex, which the native drivers replace: they still
+/// launch, but are listed only once customized through an agent file or used by a task.
+const UNLISTED: &[&str] = &["claude-acp", "codex-acp"];
+
+pub(crate) fn is_unlisted(spec: &ProviderSpec) -> bool {
+    UNLISTED.contains(&spec.id.as_str()) && builtin_spec(&spec.id).as_ref() == Some(spec)
+}
+
 /// Public launch metadata, keeping the built-in defaults separate from agent-file overrides.
 pub(crate) fn describe(spec: &ProviderSpec) -> AgentProvider {
     let builtin = builtin_spec(&spec.id);
@@ -400,6 +411,45 @@ mod tests {
     use super::*;
     use serde_json::json;
 
+    #[test]
+    fn qoder_global_and_cn_editions_are_both_built_in() {
+        let info = |id: &str| describe(&load(None).into_iter().find(|s| s.id == id).unwrap());
+        let (global, cn) = (info("qoder"), info("qodercn"));
+        assert_eq!((global.name.as_str(), global.command.as_str()), ("Qoder", "qodercli --acp"));
+        assert_eq!((cn.name.as_str(), cn.command.as_str()), ("Qoder CN", "qoderclicn --acp"));
+        assert_eq!(global.login_hint.as_deref(), Some("Run `qodercli login` in a terminal."));
+    }
+
+    #[test]
+    fn qodercn_is_available_without_a_file_and_preserves_existing_customizations() {
+        let dir = tempfile::tempdir().unwrap();
+        let qodercn = load(None).into_iter().find(|s| s.id == "qodercn").unwrap();
+        assert_eq!(qodercn.driver, Driver::Acp);
+        assert!(!is_unlisted(&qodercn));
+        let info = describe(&qodercn);
+        assert_eq!(info.name, "Qoder CN");
+        assert_eq!(info.command, "qoderclicn --acp");
+        assert_eq!(info.source, AgentSource::Builtin);
+        assert!(info.command_editable);
+        assert_eq!(info.login_hint.as_deref(), Some("Run `qoderclicn login` in a terminal."));
+
+        std::fs::write(
+            dir.path().join("qodercn.toml"),
+            "command = \"/custom/qoderclicn\"\nargs = [\"--acp\"]\n[env]\nK = \"v\"\n",
+        )
+        .unwrap();
+        let specs = load(Some(dir.path()));
+        assert_eq!(specs.iter().filter(|s| s.id == "qodercn").count(), 1);
+        let custom = specs.iter().find(|s| s.id == "qodercn").unwrap();
+        assert_eq!(custom.command, "/custom/qoderclicn");
+        assert_eq!(custom.env, [("K".into(), "v".into())]);
+        set_builtin_command(dir.path(), "qodercn", None).unwrap();
+        let reset = load(Some(dir.path())).into_iter().find(|s| s.id == "qodercn").unwrap();
+        assert_eq!(reset.command, "qoderclicn");
+        assert_eq!(reset.args, ["--acp"]);
+        assert_eq!(reset.env, custom.env);
+    }
+
     #[test]
     fn login_hints_cover_all_builtin_commands_and_preserve_separate_login_tools() {
         for spec in builtins() {
@@ -590,6 +640,15 @@ mod tests {
         set_builtin_env(dir.path(), "not-a-builtin", env).unwrap_err();
     }
 
+    #[test]
+    fn acp_adapters_of_native_agents_are_unlisted_until_customized() {
+        let dir = tempfile::tempdir().unwrap();
+        let unlisted = |dir: &Path| load(Some(dir)).into_iter().filter(is_unlisted).map(|s| s.id).collect::<Vec<_>>();
+        assert_eq!(unlisted(dir.path()), ["claude-acp", "codex-acp"]);
+        set_builtin_env(dir.path(), "codex-acp", BTreeMap::from([("A".to_owned(), "1".to_owned())])).unwrap();
+        assert_eq!(unlisted(dir.path()), ["claude-acp"]);
+    }
+
     #[test]
     fn set_builtin_command_overrides_and_clears_a_builtin() {
         let dir = tempfile::tempdir().unwrap();

crates/ide-agent/src/tests.rs

@@ -35,6 +35,9 @@ struct FakeAgent {
     /// Without `loadSession` (a session lives only as long as its process).
     no_load: bool,
     auth_on_new: bool,
+    auth_on_load: bool,
+    authenticate_method: Option<String>,
+    authenticated: AtomicBool,
     request_error: Option<(i64, String)>,
     auth_methods: Vec<Value>,
     /// Hold the late mode reply until the prompt's permission request is already waiting.
@@ -127,9 +130,9 @@ impl Handler for FakeAgent {
 
     fn on_request(&self, method: &str, params: Value) -> Result<Value, (i64, String)> {
         self.calls.lock().push(method.to_owned());
-        if (method == "session/new" && self.auth_on_new)
-            || (method == "session/prompt" && params.pointer("/prompt/0/text") == Some(&json!("auth")))
-        {
+        let needs_auth = !self.authenticated.load(Ordering::Acquire)
+            && ((method == "session/new" && self.auth_on_new) || (method == "session/load" && self.auth_on_load));
+        if needs_auth || (method == "session/prompt" && params.pointer("/prompt/0/text") == Some(&json!("auth"))) {
             return Err(self
                 .request_error
                 .clone()
@@ -176,6 +179,16 @@ impl Handler for FakeAgent {
                 self.say(&session, "replayed history");
                 Ok(json!({}))
             }
+            "authenticate" if self.authenticate_method.is_some() => {
+                let id = params.get("methodId").and_then(Value::as_str).unwrap_or_default();
+                self.calls.lock().push(format!("authenticate {id}"));
+                if Some(id) == self.authenticate_method.as_deref() {
+                    self.authenticated.store(true, Ordering::Release);
+                    Ok(json!({}))
+                } else {
+                    Err((codes::INVALID_PARAMS, format!("unexpected methodId {id}")))
+                }
+            }
             "session/set_config_option" | "session/set_mode" => {
                 self.calls.lock().push(format!("{method} {}", params.get("value").or(params.get("modeId")).unwrap()));
                 if params["configId"] == "model" && !self.model_options.lock().is_empty() {
@@ -696,6 +709,91 @@ async fn registry_sign_in_errors_use_the_advertised_terminal_login() {
     }
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn authenticates_and_retries_session_setup_once_on_auth_error() {
+    let tmp = tempfile::tempdir().unwrap();
+    let methods = vec![
+        json!({"id": "cli_login", "_meta": {"terminal-auth": {"command": "copilot", "args": ["login"]}}}),
+        json!({"id": "github_oauth", "name": "GitHub OAuth"}),
+    ];
+    let agent = Arc::new(FakeAgent {
+        auth_on_new: true,
+        authenticate_method: Some("github_oauth".into()),
+        request_error: Some((-32000, "Authentication required".into())),
+        auth_methods: methods.clone(),
+        ..Default::default()
+    });
+    let mgr = manager(tmp.path(), agent.clone());
+    let task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("again"),
+            provider: "copilot".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    assert_eq!(
+        agent
+            .calls
+            .lock()
+            .iter()
+            .filter(|c| c.starts_with("session/") || c.starts_with("authenticate"))
+            .collect::<Vec<_>>(),
+        ["session/new", "authenticate", "authenticate github_oauth", "session/new", "session/prompt"],
+    );
+
+    // Resuming after an IDE restart also authenticates once and retries `session/load`.
+    mgr.shutdown();
+    let agent2 = Arc::new(FakeAgent {
+        auth_on_load: true,
+        auth_on_new: true,
+        authenticate_method: Some("github_oauth".into()),
+        request_error: Some((-32000, "Authentication required".into())),
+        auth_methods: methods.clone(),
+        ..Default::default()
+    });
+    let mgr2 = manager(tmp.path(), agent2.clone());
+    mgr2.prompt(&task.id, text("again"), false).await.unwrap();
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    wait_for(&mgr2, &task.id, AgentStatus::Ready).await;
+    assert_eq!(
+        agent2
+            .calls
+            .lock()
+            .iter()
+            .filter(|c| c.starts_with("session/") || c.starts_with("authenticate"))
+            .collect::<Vec<_>>(),
+        ["session/load", "authenticate", "authenticate github_oauth", "session/load", "session/prompt"],
+    );
+
+    // If `authenticate` fails during `session/load`, fallback to `session/new` does not try it again.
+    mgr2.shutdown();
+    let agent3 = Arc::new(FakeAgent {
+        auth_on_load: true,
+        auth_on_new: true,
+        request_error: Some((-32000, "Authentication required".into())),
+        auth_methods: methods,
+        ..Default::default()
+    });
+    let mgr3 = manager(tmp.path(), agent3.clone());
+    mgr3.prompt(&task.id, text("again"), false).await.unwrap();
+    wait_for(&mgr3, &task.id, AgentStatus::Failed).await;
+    assert_eq!(
+        agent3
+            .calls
+            .lock()
+            .iter()
+            .filter(|c| c.starts_with("session/") || c.starts_with("authenticate"))
+            .collect::<Vec<_>>(),
+        ["session/load", "authenticate", "session/new"],
+    );
+    mgr3.shutdown();
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn commands_are_remembered_per_project_and_merged_with_skills_on_disk() {
     let tmp = tempfile::tempdir().unwrap();
@@ -2521,10 +2619,10 @@ async fn session_settings_win_over_discovery_in_memory_and_on_disk() {
         let saved = options("saved", "low");
         let discovered = options("discovered", "high");
         if discovery_first {
-            mgr.shared.remember_discovered("claude", &discovered, &[]);
+            mgr.shared.remember_discovered("claude", &discovered, &[], &[]);
         }
         mgr.shared.remember("claude", Some(&saved), None, Some("saved"));
-        mgr.shared.remember_discovered("claude", &discovered, &[]);
+        mgr.shared.remember_discovered("claude", &discovered, &[], &[]);
         let restored = manager(tmp.path(), Arc::new(FakeAgent::default()));
         for mgr in [&mgr, &restored] {
             assert_eq!(model_of(&mgr.shared.known_config("claude")).as_deref(), Some("saved"));
@@ -2532,3 +2630,143 @@ async fn session_settings_win_over_discovery_in_memory_and_on_disk() {
         }
     }
 }
+
+#[tokio::test(flavor = "multi_thread")]
+async fn discovered_effort_levels_fill_models_no_session_has_reported() {
+    let tmp = tempfile::tempdir().unwrap();
+    let mgr = manager(tmp.path(), Arc::new(FakeAgent::default()));
+    let effort = |values: &[&str], current: &str| {
+        config::options_of(&json!({ "configOptions": [
+            { "id": "effort", "category": "thought_level", "type": "select", "currentValue": current,
+              "options": values.iter().map(|v| json!({ "value": v })).collect::<Vec<_>>() }
+        ] }))
+    };
+    let model = config::options_of(&json!({ "configOptions": [
+        { "id": "model", "category": "model", "type": "select", "currentValue": "sonnet",
+          "options": [{ "value": "sonnet" }, { "value": "opus" }] }
+    ] }));
+    // A session already reported sonnet's levels; discovery adds opus's.
+    let reported = [model.clone(), effort(&["low", "high"], "high")].concat();
+    mgr.shared.remember("claude", Some(&reported), None, Some("sonnet"));
+    let levels =
+        [("sonnet".to_owned(), effort(&["low"], "low")), ("opus".to_owned(), effort(&["low", "max"], "default"))];
+    mgr.shared.remember_discovered("claude", &model, &[], &levels);
+    let known = mgr.shared.known.lock();
+    assert_eq!(known["claude"].thought_levels["sonnet"], effort(&["low", "high"], "high"), "the session's report wins");
+    assert_eq!(known["claude"].thought_levels["opus"], effort(&["low", "max"], "default"));
+}
+
+#[test]
+fn streamed_text_is_sent_as_appends() {
+    let mut streamed = HashMap::new();
+    let agent = |t: &str| AgentEntry::Agent { text: t.into() };
+    let first = entry_event("t", &mut streamed, None, 3, &agent("Hé"));
+    assert!(matches!(first, AgentEvent::Entry { index: 3, .. }), "the first sight of a message is whole");
+    let next = entry_event("t", &mut streamed, None, 3, &agent("Hé 👋 there"));
+    assert!(
+        matches!(&next, AgentEvent::Append { subagent: None, index: 3, from: 2, text, .. } if text == " 👋 there"),
+        "{next:?}"
+    );
+    let sub = entry_event("t", &mut streamed, Some("s".into()), 3, &agent("Hé 👋 there!"));
+    assert!(matches!(sub, AgentEvent::Entry { .. }), "each session streams on its own");
+    let after = entry_event("t", &mut streamed, None, 3, &agent("Hé 👋 there."));
+    assert!(
+        matches!(&after, AgentEvent::Append { from: 11, text, .. } if text == "."),
+        "from counts UTF-16 units: {after:?}"
+    );
+    let replaced = entry_event("t", &mut streamed, None, 3, &agent("Other"));
+    assert!(matches!(replaced, AgentEvent::Entry { .. }), "text that doesn't extend the sent text is sent whole");
+    let thought = entry_event("t", &mut streamed, None, 4, &AgentEntry::Thought { text: "hmm…".into() });
+    assert!(matches!(thought, AgentEvent::Entry { index: 4, .. }), "a new message starts whole");
+    let tool = AgentEntry::Error { message: "x".into() };
+    entry_event("t", &mut streamed, None, 4, &tool);
+    let again = entry_event("t", &mut streamed, None, 4, &AgentEntry::Thought { text: "hmm… ok".into() });
+    assert!(matches!(again, AgentEvent::Entry { .. }), "an entry replaced by another kind forgets its text");
+
+    let long = "é".repeat(5000);
+    entry_event("t", &mut streamed, None, 5, &agent(&long));
+    assert!(streamed[&None].tail.len() <= 64, "only the end of what was sent is kept");
+    let on = entry_event("t", &mut streamed, None, 5, &agent(&format!("{long}!")));
+    assert!(matches!(&on, AgentEvent::Append { from: 5000, text, .. } if text == "!"), "{on:?}");
+    let rewritten = entry_event("t", &mut streamed, None, 5, &agent(&format!("{}x!??", "é".repeat(4999))));
+    assert!(matches!(rewritten, AgentEvent::Entry { .. }), "a rewritten end is sent whole");
+}
+
+#[test]
+fn error_messages_keep_the_agents_details() {
+    let details = json!({ "details": "spawn claude ENOENT" });
+    assert_eq!(with_details("Internal error".into(), Some(&details)), "Internal error: spawn claude ENOENT");
+    assert_eq!(
+        with_details("Internal error".into(), Some(&json!("model not found"))),
+        "Internal error: model not found"
+    );
+    assert_eq!(with_details(String::new(), Some(&details)), "spawn claude ENOENT");
+    assert_eq!(with_details("spawn claude ENOENT".into(), Some(&details)), "spawn claude ENOENT");
+    assert_eq!(with_details("Internal error".into(), Some(&json!({ "other": 1 }))), "Internal error");
+    assert_eq!(with_details("Internal error".into(), None), "Internal error");
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edits() {
+    let tmp = tempfile::tempdir().unwrap();
+    let dir = dunce::canonicalize(tmp.path()).unwrap();
+    let git = |args: &[&str]| {
+        let ok = std::process::Command::new("git")
+            .args(["-c", "user.name=t", "-c", "user.email=t@t", "-c", "commit.gpgsign=false"])
+            .args(args)
+            .current_dir(&dir)
+            .status()
+            .unwrap()
+            .success();
+        assert!(ok, "{args:?}");
+    };
+    let write = |rel: &str, text: &str| std::fs::write(dir.join(rel), text).unwrap();
+    let read = |rel: &str| std::fs::read_to_string(dir.join(rel)).unwrap();
+    git(&["init", "-q", "-b", "main"]);
+    write(".gitignore", "store/\nworktrees/\nagents/\nmodels.json\n");
+    write("mine.txt", "base\n");
+    write("other.txt", "base\n");
+    git(&["add", "."]);
+    git(&["commit", "-q", "-m", "init"]);
+    // The user's own uncommitted edit, before the task starts.
+    write("mine.txt", "my edit\n");
+
+    let mgr = manager(&dir, Arc::new(FakeAgent::default()));
+    let task = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("Hello"),
+            provider: "claude".into(),
+            config: Vec::new(),
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
+    mgr.cancel(&task.id, None).unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    // What the agent did.
+    write("mine.txt", "my edit\nand the agent's\n");
+    write("other.txt", "agent\n");
+    write("new.txt", "agent\n");
+    async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
+        mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
+    }
+    assert_eq!(changed(&mgr, &task.id).await, ["mine.txt", "new.txt", "other.txt"]);
+
+    mgr.rollback_changes(&task.id, Some(vec!["other.txt".into()])).await.unwrap();
+    assert_eq!(read("other.txt"), "base\n");
+    assert_eq!(changed(&mgr, &task.id).await, ["mine.txt", "new.txt"]);
+
+    // After a restart, from the saved copy.
+    mgr.shutdown();
+    let mgr = manager(&dir, Arc::new(FakeAgent::default()));
+    mgr.rollback_changes(&task.id, None).await.unwrap();
+    assert_eq!(read("mine.txt"), "my edit\n", "the user's edit stays");
+    assert!(!dir.join("new.txt").exists());
+    assert!(changed(&mgr, &task.id).await.is_empty());
+
+    mgr.delete(&task.id, false).await.unwrap();
+    assert!(!dir.join("store").join(format!("{}.before", task.id)).exists());
+}

crates/ide-agent/src/worktree.rs

@@ -14,8 +14,18 @@ pub(crate) struct Created {
     pub base_commit: String,
 }
 
+/// The repository of `path`, free to execute: the host runs every agent command that
+/// reaches a repository only in a trusted project.
+fn discover(path: &Path) -> IdeResult<Option<Repo>> {
+    let repo = Repo::discover(path)?;
+    if let Some(repo) = &repo {
+        repo.set_execution_allowed(true);
+    }
+    Ok(repo)
+}
+
 fn repo_at(path: &Path) -> IdeResult<Repo> {
-    Repo::discover(path)?.ok_or_else(|| IdeError::unavailable(format!("{} is not in a git repository", path.display())))
+    discover(path)?.ok_or_else(|| IdeError::unavailable(format!("{} is not in a git repository", path.display())))
 }
 
 /// The current branch (or commit when detached) and its commit.
@@ -91,10 +101,11 @@ fn retrying(attempts: u32, pause: Duration, mut op: impl FnMut() -> std::io::Res
 /// Files under `cwd` that differ from `base` (untracked files included), with line counts.
 /// Outside a repository there is nothing to compare against: no changes.
 pub(crate) fn changes(cwd: &Path, base: &str) -> IdeResult<Vec<AgentChange>> {
-    let Some(repo) = Repo::discover(cwd)? else { return Ok(Vec::new()) };
+    let Some(repo) = discover(cwd)? else { return Ok(Vec::new()) };
     let root = repo.root().to_path_buf();
-    let stats = repo.numstat_with_worktree(base)?;
-    let stat = |rel: &str| stats.iter().find(|(p, ..)| p == rel).map_or((0, 0), |&(_, a, r)| (a, r));
+    let stats: std::collections::HashMap<String, (u32, u32)> =
+        repo.numstat_with_worktree(base)?.into_iter().map(|(p, a, r)| (p, (a, r))).collect();
+    let stat = |rel: &str| stats.get(rel).copied().unwrap_or((0, 0));
     let mut out: Vec<AgentChange> = repo
         .diff_with_worktree(base)?
         .into_iter()
@@ -103,8 +114,9 @@ pub(crate) fn changes(cwd: &Path, base: &str) -> IdeResult<Vec<AgentChange>> {
             AgentChange { path: IpcPath(root.join(&f.path)), rel_path: f.path, kind: f.kind, added, removed }
         })
         .collect();
+    let tracked: std::collections::HashSet<String> = out.iter().map(|c| c.rel_path.clone()).collect();
     for s in repo.status()? {
-        if s.unstaged == Some(ChangeKind::Untracked) && !out.iter().any(|c| c.rel_path == s.rel_path) {
+        if s.unstaged == Some(ChangeKind::Untracked) && !tracked.contains(&s.rel_path) {
             let added = std::fs::read_to_string(&*s.path).map_or(0, |t| t.lines().count() as u32);
             out.push(AgentChange { path: s.path, rel_path: s.rel_path, kind: ChangeKind::Added, added, removed: 0 });
         }
@@ -116,7 +128,7 @@ pub(crate) fn changes(cwd: &Path, base: &str) -> IdeResult<Vec<AgentChange>> {
 /// Size and modification time of a file, `None` once it is gone.
 pub(crate) type Stamp = Option<(u64, u128)>;
 
-fn stamp(path: &Path) -> Stamp {
+pub(crate) fn stamp(path: &Path) -> Stamp {
     let meta = std::fs::metadata(path).ok()?;
     let modified = meta.modified().ok()?.duration_since(UNIX_EPOCH).ok()?.as_nanos();
     Some((meta.len(), modified))
@@ -124,7 +136,10 @@ fn stamp(path: &Path) -> Stamp {
 
 /// The files already changed in `cwd` against `HEAD`, stamped so later edits to them show.
 pub(crate) fn snapshot(cwd: &Path) -> IdeResult<BTreeMap<String, Stamp>> {
-    Ok(changes(cwd, "HEAD")?.into_iter().map(|c| (c.rel_path, stamp(&c.path))).collect())
+    // Paths and stamps only: no diff and no line counts, which read every untracked file
+    // and held up starting a task in a checkout with many of them.
+    let Some(repo) = Repo::discover(cwd)? else { return Ok(BTreeMap::new()) };
+    Ok(repo.status()?.into_iter().map(|s| (s.rel_path, stamp(&s.path))).collect())
 }
 
 /// Drops the changes that were there before the task and haven't been touched since.
@@ -132,8 +147,79 @@ pub(crate) fn without_untouched(changes: Vec<AgentChange>, before: &BTreeMap<Str
     changes.into_iter().filter(|c| before.get(&c.rel_path).is_none_or(|s| *s != stamp(&c.path))).collect()
 }
 
+/// Files larger than this that were changed before the task keep no copy: they can't be rolled back.
+const SAVED_MAX: u64 = 8 * 1024 * 1024;
+
+fn saved_name(rel: &str) -> String {
+    use std::hash::{DefaultHasher, Hash, Hasher};
+    let mut hash = DefaultHasher::new();
+    rel.hash(&mut hash);
+    format!("{:016x}", hash.finish())
+}
+
+/// Copies the files in `before` (already changed in the checkout at `cwd` when the task started)
+/// into `dir`, so rolling back the task's changes to them restores the user's own edits.
+/// Whether anything was saved.
+pub(crate) fn save_before(cwd: &Path, before: &BTreeMap<String, Stamp>, dir: &Path) -> IdeResult<bool> {
+    let Some(repo) = Repo::discover(cwd)? else { return Ok(false) };
+    let mut saved = false;
+    for (rel, stamp) in before {
+        let path = repo.root().join(rel);
+        if stamp.is_none() || !std::fs::metadata(&path).is_ok_and(|m| m.is_file() && m.len() <= SAVED_MAX) {
+            continue;
+        }
+        std::fs::create_dir_all(dir)?;
+        std::fs::copy(&path, dir.join(saved_name(rel)))?;
+        saved = true;
+    }
+    Ok(saved)
+}
+
+/// Rolls `change` back: to the copy saved when the task started when the file had changes
+/// then (`before`, `saved` holding the copies), otherwise to `base` (removed when `base`
+/// lacks it).
+pub(crate) fn restore(
+    cwd: &Path,
+    base: &str,
+    change: &AgentChange,
+    before: &BTreeMap<String, Stamp>,
+    saved: Option<&Path>,
+) -> IdeResult<()> {
+    let path = &change.path.0;
+    let content = match before.get(&change.rel_path) {
+        Some(None) => None,
+        Some(Some(_)) => {
+            let copy =
+                saved.map(|d| d.join(saved_name(&change.rel_path))).filter(|p| p.is_file()).ok_or_else(|| {
+                    IdeError::invalid(format!(
+                        "{} had changes of yours when the task started that weren't saved; roll it back in Git instead",
+                        change.rel_path
+                    ))
+                })?;
+            Some(std::fs::read(copy)?)
+        }
+        None => {
+            let repo = Repo::discover(cwd)?.ok_or_else(|| IdeError::invalid("not in a git repository"))?;
+            repo.file_bytes_at(path, Some(base))?
+        }
+    };
+    match content {
+        Some(bytes) => {
+            if let Some(parent) = path.parent() {
+                std::fs::create_dir_all(parent)?;
+            }
+            std::fs::write(path, bytes)?;
+        }
+        None => match std::fs::remove_file(path) {
+            Err(e) if e.kind() != std::io::ErrorKind::NotFound => return Err(e.into()),
+            _ => {}
+        },
+    }
+    Ok(())
+}
+
 pub(crate) fn file_at(cwd: &Path, path: &Path, rev: &str) -> IdeResult<Option<String>> {
-    let Some(repo) = Repo::discover(cwd)? else { return Ok(None) };
+    let Some(repo) = discover(cwd)? else { return Ok(None) };
     let encoding = match ide_vfs::load_text(path) {
         Ok(loaded) => encoding_rs::Encoding::for_label(loaded.encoding.as_bytes()).unwrap_or(encoding_rs::UTF_8),
         Err(_) => ide_vfs::detect_encoding(&repo.file_bytes_at(path, Some(rev))?.unwrap_or_default(), None),

crates/ide-build/Cargo.toml

@@ -7,7 +7,9 @@ license.workspace = true
 
 [dependencies]
 blake3.workspace = true
+chardetng.workspace = true
 dunce.workspace = true
+encoding_rs.workspace = true
 ide-core.workspace = true
 zip.workspace = true
 serde.workspace = true

crates/ide-build/src/compile/fingerprint.rs

@@ -79,23 +79,26 @@ fn scan(
     Ok(())
 }
 
-/// `None` means an input cannot be resolved safely: build normally without reuse.
-/// All filesystem work belongs on the caller's blocking thread.
-pub fn launch_fingerprint(
+/// One planned step as fingerprinted: resolved program, args, cwd and env.
+type StepFingerprint = (PathBuf, Vec<String>, PathBuf, BTreeMap<String, String>);
+
+/// Environment, planned steps and input paths shared by every Maven build
+/// fingerprint: the filtered process environment plus the wrapper, settings
+/// and JDK files the planned invocation reads.
+struct Collected {
+    inputs: Vec<PathBuf>,
+    environment: BTreeMap<String, String>,
+    steps: Vec<StepFingerprint>,
+    inherited_hash: u64,
+}
+
+fn collect(
     root: &Path,
-    model: &BuildModel,
-    module: &Path,
-    test: bool,
+    projects: &[&maven::MavenProject],
+    plan: &BuildPlan,
     local_repo: Option<PathBuf>,
-    cancel: &CancellationToken,
-) -> IdeResult<Option<LaunchFingerprint>> {
-    let Some(m) = &model.maven else { return Ok(None) };
-    let projects = maven_launch_projects(root, m, module, test);
-    if projects.is_empty() {
-        return Ok(None);
-    }
-    let Some(mut inputs) = maven::launch_inputs(root, &projects, local_repo) else { return Ok(None) };
-    let plan = launch_plan(root, model, module, test, BuildKind::Build)?;
+) -> IdeResult<Option<Collected>> {
+    let Some(mut inputs) = maven::launch_inputs(root, projects, local_repo) else { return Ok(None) };
     let mut environment: BTreeMap<String, String> = std::env::vars()
         .map(|(key, value)| (key.to_ascii_uppercase(), value))
         .filter(|(key, _)| {
@@ -165,23 +168,132 @@ pub fn launch_fingerprint(
             Path::new(home).join(if cfg!(windows) { "bin/java.exe" } else { "bin/java" }),
         ]);
     }
-    let steps: Vec<_> =
-        plan.steps.iter().map(|s| (process::program_path(&s.program, &s.env), &s.args, &s.cwd, &s.env)).collect();
+    let steps = plan
+        .steps
+        .iter()
+        .map(|s| (process::program_path(&s.program, &s.env), s.args.clone(), s.cwd.clone(), s.env.clone()))
+        .collect();
     // Profiles and plugins can read arbitrary environment variables. Keep a signature
     // of the inherited environment without persisting unrelated credentials.
     let inherited: BTreeMap<_, _> = std::env::vars_os().collect();
     let mut inherited_hash = std::hash::DefaultHasher::new();
     inherited.hash(&mut inherited_hash);
-    let parameters =
-        serde_json::to_string(&(root, module, test, steps, environment, inherited_hash.finish(), projects))
-            .map_err(|e| IdeError::internal(e.to_string()))?;
+    Ok(Some(Collected { inputs, environment, steps, inherited_hash: inherited_hash.finish() }))
+}
+
+/// Scans every input, storing project inputs relative to the project.
+fn scan_all(
+    root: &Path,
+    inputs: Vec<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<BTreeMap<PathBuf, Option<Stamp>>> {
     let mut files = BTreeMap::new();
     for path in inputs {
         scan(root, &path, &mut files, &mut HashSet::new(), cancel)?;
     }
     // Store project inputs relative to the project, including each file's relative path.
-    let files = files.into_iter().map(|(p, stamp)| (p.strip_prefix(root).unwrap_or(&p).to_path_buf(), stamp)).collect();
-    Ok(Some(LaunchFingerprint { version: 2, parameters, files }))
+    Ok(files.into_iter().map(|(p, stamp)| (p.strip_prefix(root).unwrap_or(&p).to_path_buf(), stamp)).collect())
+}
+
+/// `None` means an input cannot be resolved safely: build normally without reuse.
+/// All filesystem work belongs on the caller's blocking thread.
+pub fn launch_fingerprint(
+    root: &Path,
+    model: &BuildModel,
+    module: &Path,
+    test: bool,
+    local_repo: Option<PathBuf>,
+    cancel: &CancellationToken,
+) -> IdeResult<Option<LaunchFingerprint>> {
+    let Some(m) = &model.maven else { return Ok(None) };
+    let projects = maven_launch_projects(root, m, module, test);
+    if projects.is_empty() {
+        return Ok(None);
+    }
+    let plan = launch_plan(root, model, module, test, BuildKind::Build)?;
+    let Some(collected) = collect(root, &projects, &plan, local_repo)? else { return Ok(None) };
+    let Collected { inputs, environment, steps, inherited_hash } = collected;
+    let parameters = serde_json::to_string(&(root, module, test, steps, environment, inherited_hash, projects))
+        .map_err(|e| IdeError::internal(e.to_string()))?;
+    Ok(Some(LaunchFingerprint { version: 2, parameters, files: scan_all(root, inputs, cancel)? }))
+}
+
+/// Inputs fingerprint of a menu build (`Build Project` / `Build Module`): the
+/// built modules' sources, resources and POM chain plus the exact planned
+/// steps, so an unchanged project skips Maven entirely (#2476). Only `Build`
+/// callers reuse it, never `Rebuild` or `Artifacts`; `None` disables reuse.
+/// All filesystem work belongs on the caller's blocking thread.
+pub fn menu_fingerprint(
+    root: &Path,
+    model: &BuildModel,
+    file: Option<&Path>,
+    cancel: &CancellationToken,
+) -> IdeResult<Option<LaunchFingerprint>> {
+    let plan = plan(root, model, BuildKind::Build, file, None)?;
+    if plan.system != BuildSystem::Maven {
+        return Ok(None);
+    }
+    let Some(m) = &model.maven else { return Ok(None) };
+    let projects: Vec<&maven::MavenProject> = match file {
+        Some(file) => {
+            // The innermost linked project owning the file, as in single-file compilation.
+            let rel = rel_str(root, file);
+            let module = m
+                .projects
+                .iter()
+                .filter(|p| rel == p.dir || rel.starts_with(&format!("{}/", p.dir)) || p.dir.is_empty())
+                .max_by_key(|p| p.dir.len());
+            match module {
+                Some(project) if project.packaging != "pom" => {
+                    maven_launch_projects(root, m, &subdir(root, &project.dir), true)
+                }
+                _ => return Ok(None),
+            }
+        }
+        // A project build walks every linked project.
+        None => m.projects.iter().collect(),
+    };
+    if projects.is_empty() {
+        return Ok(None);
+    }
+    let Some(collected) = collect(root, &projects, &plan, None)? else { return Ok(None) };
+    let Collected { inputs, environment, steps, inherited_hash } = collected;
+    let scope = file.map(|f| rel_str(root, f));
+    let parameters = serde_json::to_string(&("menu-build", scope, steps, environment, inherited_hash))
+        .map_err(|e| IdeError::internal(e.to_string()))?;
+    Ok(Some(LaunchFingerprint { version: 2, parameters, files: scan_all(root, inputs, cancel)? }))
+}
+
+impl LaunchFingerprint {
+    /// Folders (relative to the project) of the Maven projects whose POM is an input.
+    pub(super) fn project_dirs(&self) -> impl Iterator<Item = &Path> {
+        self.files
+            .keys()
+            .filter(|p| p.is_relative() && p.file_name().is_some_and(|n| n == "pom.xml"))
+            .map(|pom| pom.parent().unwrap_or(Path::new("")))
+    }
+
+    /// Relative paths whose content changed while `(length, mtime)` stayed the same
+    /// compared to `previous` (timestamp-preserving external edits, coarse-granularity
+    /// filesystems). Timestamp-incremental builders (Maven, the Kotlin plugin) would
+    /// skip these sources as "unchanged", so the rebuild the fingerprint triggers
+    /// compiles nothing and the stale outputs get re-recorded as fresh. Callers
+    /// re-stamp the returned paths before building. Inputs without a content hash
+    /// (directories, files outside the project) are never reported.
+    pub fn mtime_preserved_edits(&self, current: &Self) -> Vec<PathBuf> {
+        let mut edits = Vec::new();
+        for (path, current_stamp) in &current.files {
+            let Some(current_stamp) = current_stamp else { continue };
+            let Some(previous_stamp) = self.files.get(path).and_then(|stamp| stamp.as_ref()) else { continue };
+            let (len, mtime, Some(current_hash)) = current_stamp else { continue };
+            let (prev_len, prev_mtime, Some(prev_hash)) = previous_stamp else { continue };
+            if current_hash != prev_hash && len == prev_len && mtime == prev_mtime {
+                edits.push(path.clone());
+            }
+        }
+        edits.sort();
+        edits
+    }
 }
 
 #[cfg(test)]
@@ -282,6 +394,60 @@ mod tests {
         assert_ne!(before, after, "a same-length, same-mtime content change must invalidate the fingerprint");
     }
 
+    #[test]
+    fn mtime_preserved_edits_only_reports_lying_timestamps() {
+        fn stamp(len: u64, hash: &str) -> Option<Stamp> {
+            Some((len, SystemTime::UNIX_EPOCH + std::time::Duration::from_secs(42), Some(hash.into())))
+        }
+        fn prints(
+            previous: BTreeMap<PathBuf, Option<Stamp>>,
+            current: BTreeMap<PathBuf, Option<Stamp>>,
+        ) -> Vec<PathBuf> {
+            let previous = LaunchFingerprint { version: 2, parameters: String::new(), files: previous };
+            let current = LaunchFingerprint { version: 2, parameters: String::new(), files: current };
+            previous.mtime_preserved_edits(&current)
+        }
+        // Same length and mtime, different content: the builder would skip it.
+        assert_eq!(
+            prints([("a.java".into(), stamp(5, "old"))].into(), [("a.java".into(), stamp(5, "new"))].into()),
+            vec![PathBuf::from("a.java")]
+        );
+        // A normal edit bumps the mtime: the builder already sees it.
+        let mut touched = stamp(5, "new").unwrap();
+        touched.1 += std::time::Duration::from_secs(1);
+        assert!(
+            prints([("a.java".into(), stamp(5, "old"))].into(), [("a.java".into(), Some(touched))].into()).is_empty()
+        );
+        // Added, deleted, and hash-less inputs (directories, files outside the
+        // project) carry no comparable content: never reported.
+        assert!(
+            prints(
+                [("gone.java".into(), stamp(5, "old")), ("dir".into(), None)].into(),
+                [("new.java".into(), stamp(5, "new")), ("dir".into(), None)].into()
+            )
+            .is_empty()
+        );
+    }
+
+    #[test]
+    fn lying_source_is_found_against_a_real_fingerprint() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let source = root.join("lib/src/main/kotlin/Channel.kt");
+        let before = fingerprint(root, &model).unwrap();
+        let mtime = fs::metadata(&source).unwrap().modified().unwrap();
+        // Same 5-byte length, different content, preserved mtime.
+        write(root, "lib/src/main/kotlin/Channel.kt", "valve");
+        fs::File::options().write(true).open(&source).unwrap().set_modified(mtime).unwrap();
+        let after = fingerprint(root, &model).unwrap();
+        assert_eq!(before.mtime_preserved_edits(&after), [PathBuf::from("lib/src/main/kotlin/Channel.kt")]);
+        // A normal edit (mtime advances) needs no repair.
+        write(root, "lib/src/main/kotlin/Channel.kt", "valve!");
+        let normal = fingerprint(root, &model).unwrap();
+        assert!(before.mtime_preserved_edits(&normal).is_empty());
+    }
+
     #[test]
     fn profile_options_jdk_goal_and_wrapper_invalidate_without_using_class_outputs() {
         let dir = tempfile::tempdir().unwrap();

crates/ide-build/src/compile/launch_resources.rs

@@ -0,0 +1,253 @@
+//! Resources a Gradle build changes while copying them (filters, `expand`, renames, extra
+//! sources). The Java language server copies them as they are into Buildship's
+//! `bin/<source set>` folders, which launches run from; IntelliJ IDEA runs Gradle's copy.
+//! Before a launch, Gradle processes them and its output replaces those plain copies, so
+//! each resource is on the classpath once, as the build produces it.
+use super::{BuildPlan, BuildStep, BuildSystem, Format, run, subdir};
+use crate::BuildModel;
+use crate::gradle::{self, GradleModel, ReportedProject};
+use ide_core::{CancellationToken, IdeError, IdeResult, Severity};
+use std::fs;
+use std::path::{Path, PathBuf};
+
+/// A source set whose resources Gradle processes, with the folder the launch reads them from.
+#[derive(Debug, PartialEq)]
+struct Target {
+    /// Task path from the root build (`:app:processResources`).
+    task: String,
+    /// Where the task writes the resources.
+    output: PathBuf,
+    /// The Java language server's output folder of the source set, on the launch classpath.
+    jdtls: PathBuf,
+}
+
+fn targets(reported: &[ReportedProject], class_paths: &[String]) -> Vec<Target> {
+    // buildSrc is built before the build, never addressable as `:buildSrc:<task>`.
+    let addressable = |p: &&ReportedProject| !p.build.as_deref().is_some_and(|b| b.ends_with(":buildSrc"));
+    let sets: Vec<_> = reported
+        .iter()
+        .filter(addressable)
+        .flat_map(|p| p.source_sets.iter().filter_map(move |s| Some((p, s, s.processed.as_ref()?))))
+        .collect();
+    if sets.is_empty() {
+        return Vec::new();
+    }
+    // Canonical, as Gradle reports its folders: jdtls may spell them differently.
+    let entries: Vec<PathBuf> = class_paths.iter().filter_map(|p| dunce::canonicalize(p).ok()).collect();
+    sets.into_iter()
+        .filter_map(|(p, set, resources)| {
+            // Buildship's output folder of the source set.
+            let jdtls = dunce::canonicalize(Path::new(&p.dir).join("bin").join(&set.name)).ok()?;
+            let project = if p.path == ":" { "" } else { p.path.as_str() };
+            entries.contains(&jdtls).then(|| Target {
+                task: format!("{project}:{}", resources.task),
+                output: PathBuf::from(&resources.dir),
+                jdtls,
+            })
+        })
+        .collect()
+}
+
+/// Before a JVM launch from the Java language server's output folders on `class_paths`:
+/// runs the Gradle tasks that process resources of those folders' source sets (see the
+/// module docs) and copies their output over the plain copies. `cache_dir` holds the
+/// linked builds' last syncs. Returns the tasks run, none for builds that copy their
+/// resources as they are.
+pub fn process_launch_resources(
+    root: &Path,
+    model: &BuildModel,
+    cache_dir: &Path,
+    class_paths: &[String],
+    cancel: &CancellationToken,
+) -> IdeResult<Vec<String>> {
+    // A composite also reports the builds it includes: the deepest build owning a folder runs its task.
+    let mut builds: Vec<&GradleModel> = model.gradle.iter().collect();
+    builds.sort_by_key(|g| std::cmp::Reverse(subdir(root, &g.dir).components().count()));
+    let mut done: Vec<PathBuf> = Vec::new();
+    let mut tasks = Vec::new();
+    for g in builds {
+        let reported = crate::sync::reported_gradle_projects(&gradle::cache_dir(cache_dir, &g.dir));
+        let targets: Vec<Target> =
+            targets(&reported, class_paths).into_iter().filter(|t| !done.contains(&t.jdtls)).collect();
+        if targets.is_empty() {
+            continue;
+        }
+        let mut step = BuildStep::new(&g.command, &["--console=plain"], &subdir(root, &g.dir), Format::Gradle);
+        step.args.extend(targets.iter().map(|t| t.task.clone()));
+        step.env = g.env.clone();
+        let plan = BuildPlan { system: BuildSystem::Gradle, title: "Process resources".into(), steps: vec![step] };
+        let result = run(root, &plan, cancel, &|_| {})?;
+        if !result.success {
+            let errors: Vec<&str> = result
+                .messages
+                .iter()
+                .filter(|m| m.severity == Severity::Error)
+                .take(5)
+                .map(|m| m.text.as_str())
+                .collect();
+            return Err(IdeError::internal(errors.join("\n")));
+        }
+        for t in targets {
+            if cancel.is_cancelled() {
+                return Err(IdeError::cancelled());
+            }
+            overlay(&t.output, &t.output, &t.jdtls)?;
+            done.push(t.jdtls);
+            tasks.push(t.task);
+        }
+    }
+    Ok(tasks)
+}
+
+/// Copies the files under `dir` to the same place under `to` (relative to `base`) where
+/// they differ, so unchanged resources are not rewritten on every launch.
+fn overlay(base: &Path, dir: &Path, to: &Path) -> IdeResult<()> {
+    let entries = match fs::read_dir(dir) {
+        // No resources: the task had nothing to copy.
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(()),
+        entries => entries?,
+    };
+    for entry in entries {
+        let entry = entry?;
+        let path = entry.path();
+        let kind = entry.file_type()?;
+        if kind.is_dir() {
+            overlay(base, &path, to)?;
+        } else if kind.is_file() {
+            let dest = to.join(path.strip_prefix(base).map_err(|e| IdeError::internal(e.to_string()))?);
+            if !same_content(&path, &dest) {
+                if let Some(parent) = dest.parent() {
+                    fs::create_dir_all(parent)?;
+                }
+                fs::copy(&path, &dest)?;
+            }
+        }
+    }
+    Ok(())
+}
+
+fn same_content(a: &Path, b: &Path) -> bool {
+    match (fs::metadata(a), fs::metadata(b)) {
+        (Ok(m), Ok(n)) if m.len() == n.len() => matches!((fs::read(a), fs::read(b)), (Ok(x), Ok(y)) if x == y),
+        _ => false,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::gradle::{ProcessedResources, ReportedSourceSet};
+
+    fn write(path: &Path, text: &str) {
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, text).unwrap();
+    }
+
+    fn set(name: &str, processed: Option<&Path>) -> ReportedSourceSet {
+        ReportedSourceSet {
+            name: name.into(),
+            test: name == "test",
+            processed: processed.map(|dir| ProcessedResources {
+                task: if name == "main" { "processResources".into() } else { "processTestResources".into() },
+                dir: dir.to_string_lossy().into_owned(),
+            }),
+            ..Default::default()
+        }
+    }
+
+    fn project(path: &str, dir: &Path, sets: Vec<ReportedSourceSet>) -> ReportedProject {
+        ReportedProject {
+            path: path.into(),
+            dir: dir.to_string_lossy().into_owned(),
+            source_sets: sets,
+            ..Default::default()
+        }
+    }
+
+    /// Only processed source sets whose jdtls output is on the classpath: the launched
+    /// module, upstream modules of the build, tests only for a test classpath; never buildSrc.
+    #[test]
+    fn targets_are_processed_sets_on_the_classpath() {
+        let tmp = tempfile::tempdir().unwrap();
+        let root = dunce::canonicalize(tmp.path()).unwrap();
+        let (app, lib, plain, src) = (root.join("app"), root.join("lib"), root.join("plain"), root.join("buildSrc"));
+        for dir in [&root, &app, &lib, &plain, &src] {
+            for set in ["main", "test"] {
+                fs::create_dir_all(dir.join("bin").join(set)).unwrap();
+            }
+        }
+        let out = |dir: &Path, set: &str| dir.join("build/resources").join(set);
+        let mut build_src = project(":buildSrc", &src, vec![set("main", Some(&out(&src, "main")))]);
+        build_src.build = Some(":buildSrc".into());
+        let reported = [
+            project(":", &root, vec![set("main", Some(&out(&root, "main")))]),
+            project(":app", &app, vec![set("main", Some(&out(&app, "main"))), set("test", Some(&out(&app, "test")))]),
+            project(":lib", &lib, vec![set("main", Some(&out(&lib, "main")))]),
+            project(":plain", &plain, vec![set("main", None)]),
+            build_src,
+        ];
+        let entry = |dir: &Path, set: &str| dir.join("bin").join(set).to_string_lossy().into_owned();
+        let runtime = [
+            entry(&app, "main"),
+            // Spelled differently from Gradle's canonical folders.
+            format!("{}/", entry(&lib, "main")),
+            entry(&plain, "main"),
+            entry(&src, "main"),
+            "/m2/spring-core.jar".into(),
+        ];
+        let tasks = |cp: &[String]| targets(&reported, cp).into_iter().map(|t| t.task).collect::<Vec<_>>();
+        assert_eq!(tasks(&runtime), [":app:processResources", ":lib:processResources"]);
+        let mut test = runtime.to_vec();
+        test.insert(0, entry(&app, "test"));
+        assert_eq!(tasks(&test), [":app:processResources", ":app:processTestResources", ":lib:processResources"]);
+        assert_eq!(tasks(&[entry(&root, "main")]), [":processResources"], "the root project");
+        let app_targets = targets(&reported, &runtime);
+        let t = &app_targets[0];
+        assert_eq!(
+            (t.output.as_path(), t.jdtls.as_path()),
+            (out(&app, "main").as_path(), app.join("bin/main").as_path())
+        );
+
+        let unprocessed = [project(":app", &app, vec![set("main", None)])];
+        assert!(targets(&unprocessed, &runtime).is_empty());
+    }
+
+    /// The processed copy replaces jdtls's plain one (the reported `@version@` case), new
+    /// files are added, identical ones are left alone and files Gradle doesn't produce stay.
+    #[test]
+    fn overlay_replaces_plain_copies_with_gradle_output() {
+        let tmp = tempfile::tempdir().unwrap();
+        let (output, jdtls) = (tmp.path().join("build/resources/main"), tmp.path().join("bin/main"));
+        write(&output.join("application.yaml"), "spring:\n  application:\n    version: 0.0.1\n");
+        write(&output.join("static/extra.txt"), "from an extra source");
+        write(&output.join("migrations/V1__init.sql"), "create table t (id int);");
+        write(&jdtls.join("application.yaml"), "spring:\n  application:\n    version: @version@\n");
+        write(&jdtls.join("migrations/V1__init.sql"), "create table t (id int);");
+        write(&jdtls.join("com/example/App.class"), "bytecode");
+        let unchanged = fs::metadata(jdtls.join("migrations/V1__init.sql")).unwrap().modified().unwrap();
+        std::thread::sleep(std::time::Duration::from_millis(20));
+
+        overlay(&output, &output, &jdtls).unwrap();
+        let read = |rel: &str| fs::read_to_string(jdtls.join(rel)).unwrap();
+        assert_eq!(read("application.yaml"), "spring:\n  application:\n    version: 0.0.1\n");
+        assert_eq!(read("static/extra.txt"), "from an extra source");
+        assert_eq!(read("com/example/App.class"), "bytecode");
+        let modified = fs::metadata(jdtls.join("migrations/V1__init.sql")).unwrap().modified().unwrap();
+        assert_eq!(modified, unchanged, "identical files are not rewritten");
+
+        overlay(&tmp.path().join("missing"), &tmp.path().join("missing"), &jdtls).unwrap();
+    }
+
+    #[test]
+    fn builds_without_processed_resources_run_nothing() {
+        let tmp = tempfile::tempdir().unwrap();
+        // Running this command would fail the call.
+        let missing = tmp.path().join("missing-gradle").to_string_lossy().into_owned();
+        let model =
+            BuildModel { gradle: vec![GradleModel { command: missing, ..Default::default() }], ..Default::default() };
+        let class_paths = [tmp.path().join("bin/main").to_string_lossy().into_owned()];
+        let tasks =
+            process_launch_resources(tmp.path(), &model, tmp.path(), &class_paths, &CancellationToken::new()).unwrap();
+        assert!(tasks.is_empty());
+    }
+}

crates/ide-build/src/compile/mod.rs

@@ -4,9 +4,17 @@
 //! for the Build tool window, the Problems view and the editor.
 
 mod fingerprint;
+mod launch_resources;
 mod parse;
+mod single;
+mod up_to_date;
 
-pub use fingerprint::{LaunchFingerprint, launch_fingerprint};
+pub use fingerprint::{LaunchFingerprint, launch_fingerprint, menu_fingerprint};
+pub use launch_resources::process_launch_resources;
+pub use single::{
+    SingleFileTarget, compile_file_plan, find_javac, javac_step, single_file_classpath, single_file_target,
+};
+pub use up_to_date::{menu_up_to_date, record_menu_build};
 
 use crate::process::{self, Stream};
 use crate::{BuildModel, maven};
@@ -263,7 +271,12 @@ pub(super) fn maven_steps(
         return Err(IdeError::not_found("no Maven project found"));
     }
     let step = |p: &maven::MavenProject, extra: &[String]| {
-        let mut s = BuildStep::new(&p.command, &["-B", "-Dstyle.color=never"], &subdir(root, &p.dir), Format::Maven);
+        let mut s = BuildStep::new(
+            &p.command,
+            &["-B", "-Dstyle.color=never", maven::LOCAL_REPO_TRACKING_ARG],
+            &subdir(root, &p.dir),
+            Format::Maven,
+        );
         s.args.extend(p.options.iter().cloned());
         s.args.extend(extra.iter().cloned());
         s.args.extend(goals.iter().map(|g| (*g).to_owned()));
@@ -1044,9 +1057,21 @@ mod tests {
         assert_eq!(p.system, BuildSystem::Maven);
         assert_eq!(p.title, "demo");
         assert_eq!(p.steps.len(), 1);
-        assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", "test-compile"]);
+        assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", maven::LOCAL_REPO_TRACKING_ARG, "test-compile"]);
         let p = plan(&root, &model, BuildKind::Rebuild, Some(&root.join("core/src/main/java/A.java")), None).unwrap();
-        assert_eq!(p.steps[0].args, ["-B", "-Dstyle.color=never", "-pl", "core", "-am", "clean", "test-compile"]);
+        assert_eq!(
+            p.steps[0].args,
+            [
+                "-B",
+                "-Dstyle.color=never",
+                maven::LOCAL_REPO_TRACKING_ARG,
+                "-pl",
+                "core",
+                "-am",
+                "clean",
+                "test-compile"
+            ]
+        );
         assert_eq!(p.steps[0].cwd, root);
         assert_eq!(p.title, "demo: build module 'core'");
 
@@ -1320,12 +1345,36 @@ mod tests {
             assert_eq!(step.cwd, root);
             assert_eq!(step.program, "mvnw");
             assert_eq!(step.env["JAVA_HOME"], "/jdk");
-            assert_eq!(step.args, ["-B", "-Dstyle.color=never", "-s", "settings.xml", "-pl", "app", "-am", goal]);
+            assert_eq!(
+                step.args,
+                [
+                    "-B",
+                    "-Dstyle.color=never",
+                    maven::LOCAL_REPO_TRACKING_ARG,
+                    "-s",
+                    "settings.xml",
+                    "-pl",
+                    "app",
+                    "-am",
+                    goal
+                ]
+            );
             // Rebuild cleans first, as IDEA's Rebuild does.
             let plan = launch_plan(root, &model, &root.join("app"), test, BuildKind::Rebuild).unwrap();
             assert_eq!(
                 plan.steps[0].args,
-                ["-B", "-Dstyle.color=never", "-s", "settings.xml", "-pl", "app", "-am", "clean", goal]
+                [
+                    "-B",
+                    "-Dstyle.color=never",
+                    maven::LOCAL_REPO_TRACKING_ARG,
+                    "-s",
+                    "settings.xml",
+                    "-pl",
+                    "app",
+                    "-am",
+                    "clean",
+                    goal
+                ]
             );
         }
     }

crates/ide-build/src/compile/parse.rs

@@ -7,6 +7,7 @@
 //! [`super::resolve`] turns them into IDE coordinates.
 
 use ide_core::Severity;
+pub(crate) use ide_core::output_encoding::strip_ansi;
 use serde_json::Value;
 
 /// Output dialect of a build step.
@@ -98,32 +99,6 @@ pub(crate) struct OutputParser {
     pending: Option<Pending>,
 }
 
-/// Removes ANSI escape sequences (colour, cursor movement).
-pub(crate) fn strip_ansi(s: &str) -> String {
-    if !s.contains('\u{1b}') {
-        return s.to_owned();
-    }
-    let mut out = String::with_capacity(s.len());
-    let mut chars = s.chars().peekable();
-    while let Some(c) = chars.next() {
-        if c != '\u{1b}' {
-            out.push(c);
-            continue;
-        }
-        if chars.peek() == Some(&'[') {
-            chars.next();
-            for c in chars.by_ref() {
-                if c.is_ascii_alphabetic() || c == '~' {
-                    break;
-                }
-            }
-        } else {
-            chars.next();
-        }
-    }
-    out
-}
-
 fn num(s: &str) -> Option<u32> {
     s.trim().parse().ok().filter(|n| *n > 0)
 }

crates/ide-build/src/compile/single.rs

@@ -0,0 +1,331 @@
+//! Single-file Java compilation with `javac` for the Compile File action (#2476).
+//!
+//! A module build (`-pl … -am`) still walks every upstream module, and packaging
+//! walks the whole reactor; compiling one file only needs that file's module
+//! outputs plus its dependency classpath, which is much faster to assemble.
+use super::*;
+use std::fs;
+use std::process::Command as ProcCommand;
+
+/// Output file of the `dependency:build-classpath` probe, relative to each module.
+const CP_FILE: &str = "target/ide-compile-cp.txt";
+
+/// A `.java` source and the module build that compiles it.
+pub struct SingleFileTarget {
+    /// Absolute module directory.
+    pub module: PathBuf,
+    /// The source is under `src/test`: compile to test classes with the test classpath.
+    pub test: bool,
+    /// Absolute `target/classes` (or `target/test-classes`).
+    pub out_dir: PathBuf,
+    /// Reactor root building the module (owns the Maven command and options).
+    pub top: maven::MavenProject,
+    /// `-pl` value of the module relative to the reactor root; empty when the
+    /// module is the root itself.
+    pub pl: String,
+    /// `maven.compiler.release` (or equivalent) of the module's project.
+    pub java_version: Option<u32>,
+}
+
+/// Locates the linked Maven module owning a `.java` source file.
+pub fn single_file_target(root: &Path, model: &BuildModel, file: &Path) -> IdeResult<SingleFileTarget> {
+    if file.extension().is_none_or(|ext| ext != "java") {
+        return Err(IdeError::invalid("only Java sources can be compiled as a single file"));
+    }
+    if !file.is_file() {
+        return Err(IdeError::not_found("no Java source found for single-file compilation"));
+    }
+    let Some(m) = &model.maven else {
+        return Err(IdeError::not_found("no linked Maven project found for module"));
+    };
+    // The innermost project whose directory contains the file owns it; the
+    // aggregator root (`""`) is a prefix of everything, so take the longest match.
+    let rel = rel_str(root, file);
+    let project = m
+        .projects
+        .iter()
+        .filter(|p| rel == p.dir || rel.starts_with(&format!("{}/", p.dir)) || p.dir.is_empty())
+        .max_by_key(|p| p.dir.len())
+        .ok_or_else(|| IdeError::not_found("no linked Maven project found for module"))?;
+    if project.packaging == "pom" {
+        // An aggregator owns no sources itself: a file that only matches it
+        // belongs to no linked module.
+        return Err(IdeError::not_found("no linked Maven project found for module"));
+    }
+    let module = subdir(root, &project.dir);
+    let top = maven_reactor(m, &project.dir)
+        .ok_or_else(|| IdeError::not_found("no linked Maven project found for module"))?;
+    let top_dir = subdir(root, &top.dir);
+    let pl = module.strip_prefix(&top_dir).map(|r| r.to_string_lossy().replace('\\', "/")).unwrap_or_default();
+    // Test sources see the test classpath and compile into test classes.
+    let parts: Vec<&str> = rel.split('/').collect();
+    let test = parts.windows(2).any(|w| w == ["src", "test"]);
+    let out_dir = module.join("target").join(if test { "test-classes" } else { "classes" });
+    Ok(SingleFileTarget { module, test, out_dir, top: top.clone(), pl, java_version: project.java_version })
+}
+
+/// `javac` for the module: its `JAVA_HOME`, else `PATH`.
+pub fn find_javac(env: &BTreeMap<String, String>) -> String {
+    let home = env.get("JAVA_HOME").map(Path::new);
+    let exe = if cfg!(windows) { "javac.exe" } else { "javac" };
+    if let Some(javac) = home.map(|h| h.join("bin").join(exe)).filter(|p| p.is_file()) {
+        return javac.to_string_lossy().into_owned();
+    }
+    exe.to_owned()
+}
+
+/// Dependency classpath of the module: existing reactor class directories plus
+/// `mvn dependency:build-classpath` (which resolves without compiling anything,
+/// so `-am` stays cheap). Entries are platform-separated (`;` on Windows).
+pub fn single_file_classpath(root: &Path, model: &BuildModel, target: &SingleFileTarget) -> IdeResult<String> {
+    let mut entries: Vec<String> = Vec::new();
+    // The module's own classes first: the file almost always uses classes next to it.
+    let own: &[&str] = if target.test { &["target/test-classes", "target/classes"] } else { &["target/classes"] };
+    for out in own {
+        let path = target.module.join(out);
+        if path.is_dir() {
+            entries.push(path.to_string_lossy().into_owned());
+        }
+    }
+    if let Some(m) = &model.maven {
+        // Upstream reactor modules first: their freshly built classes shadow
+        // installed snapshots of the same artifacts.
+        for project in maven_launch_projects(root, m, &target.module, target.test) {
+            let dir = subdir(root, &project.dir);
+            if dir == target.module {
+                continue;
+            }
+            for classes in ["target/classes", "target/test-classes"] {
+                let path = dir.join(classes);
+                if path.is_dir() {
+                    entries.push(path.to_string_lossy().into_owned());
+                }
+            }
+        }
+    }
+    let probe = CP_FILE;
+    let mut args = vec!["-B", "-Dstyle.color=never", maven::LOCAL_REPO_TRACKING_ARG];
+    args.extend(target.top.options.iter().map(String::as_str));
+    if !target.pl.is_empty() {
+        args.extend(["-pl", target.pl.as_str(), "-am"]);
+    }
+    let output_arg = format!("-Dmdep.outputFile={probe}");
+    args.extend(["dependency:build-classpath", output_arg.as_str(), "-Dmdep.includeScope=test", "-q"]);
+    let top_dir = subdir(root, &target.top.dir);
+    let status = ProcCommand::new(&target.top.command)
+        .args(&args)
+        .envs(&target.top.env)
+        .current_dir(&top_dir)
+        .output()
+        .map_err(|e| IdeError::internal(format!("cannot resolve the compile classpath: {e}")))?;
+    if !status.status.success() {
+        let stderr = String::from_utf8_lossy(&status.stderr);
+        let tail: Vec<&str> = stderr.lines().filter(|l| !l.trim().is_empty()).collect();
+        let tail = tail.iter().rev().take(5).rev().cloned().collect::<Vec<_>>().join("\n");
+        return Err(IdeError::internal(format!("cannot resolve the compile classpath:\n{tail}")));
+    }
+    // With `-am` every visited module writes its own file; only this module's counts.
+    let cp_file = target.module.join(probe);
+    let content = fs::read_to_string(&cp_file).map_err(|e| {
+        IdeError::internal(format!("cannot resolve the compile classpath: {} ({e})", cp_file.display()))
+    })?;
+    let separator = if cfg!(windows) { ';' } else { ':' };
+    entries.extend(content.split([separator, '\n', '\r']).map(str::trim).filter(|e| !e.is_empty()).map(str::to_owned));
+    entries.dedup();
+    Ok(entries.join(&separator.to_string()))
+}
+
+/// The `javac` step compiling `file` into `target`'s output directory.
+pub fn javac_step(target: &SingleFileTarget, file: &Path, classpath: &str, javac: &str) -> IdeResult<BuildStep> {
+    fs::create_dir_all(&target.out_dir)
+        .map_err(|e| IdeError::internal(format!("cannot create {} ({e})", target.out_dir.display())))?;
+    let mut step = BuildStep::new(javac, &[], &target.module, Format::Gradle);
+    // Raw `javac` prints `path:line: error: …`, the same form Gradle forwards.
+    step.args.push("-encoding".into());
+    step.args.push("UTF-8".into());
+    step.args.push("-d".into());
+    step.args.push(target.out_dir.to_string_lossy().into_owned());
+    step.args.push("-cp".into());
+    step.args.push(classpath.to_owned());
+    // Classes of the module that were never built (or are older than their source) are read
+    // from its sources; only `file` is written, so a test compile never puts main classes
+    // into test-classes.
+    let sources = source_roots(target);
+    if !sources.is_empty() {
+        let separator = if cfg!(windows) { ";" } else { ":" };
+        step.args.push("-sourcepath".into());
+        step.args.push(sources.iter().map(|p| p.to_string_lossy()).collect::<Vec<_>>().join(separator));
+        step.args.push("-implicit:none".into());
+    }
+    if let Some(version) = target.java_version {
+        step.args.push("--release".into());
+        step.args.push(version.to_string());
+    }
+    step.args.push(file.to_string_lossy().into_owned());
+    step.env = target.top.env.clone();
+    Ok(step)
+}
+
+/// The module's Java source folders that exist, generated ones included; test sources see
+/// the main ones too.
+fn source_roots(target: &SingleFileTarget) -> Vec<PathBuf> {
+    let scopes: &[(&str, &str)] = if target.test {
+        &[("src/test/java", "target/generated-test-sources"), ("src/main/java", "target/generated-sources")]
+    } else {
+        &[("src/main/java", "target/generated-sources")]
+    };
+    let mut roots = Vec::new();
+    for (src, generated) in scopes {
+        roots.push(target.module.join(src));
+        let generated = target.module.join(generated);
+        let mut dirs: Vec<PathBuf> =
+            fs::read_dir(&generated).into_iter().flatten().flatten().map(|d| d.path()).filter(|p| p.is_dir()).collect();
+        dirs.sort();
+        roots.extend(dirs);
+    }
+    roots.retain(|p| p.is_dir());
+    roots
+}
+
+/// Resolves the classpath and plans the `javac` invocation for one Java source.
+pub fn compile_file_plan(root: &Path, model: &BuildModel, file: &Path) -> IdeResult<BuildPlan> {
+    let target = single_file_target(root, model, file)?;
+    let classpath = single_file_classpath(root, model, &target)?;
+    let javac = find_javac(&target.top.env);
+    let name = file.file_name().map(|n| n.to_string_lossy().into_owned()).unwrap_or_default();
+    Ok(BuildPlan {
+        system: BuildSystem::Maven,
+        title: format!("Compile {name}"),
+        steps: vec![javac_step(&target, file, &classpath, &javac)?],
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn write(root: &Path, rel: &str, value: &str) {
+        let path = root.join(rel);
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, value).unwrap();
+    }
+
+    fn fixture(root: &Path) -> BuildModel {
+        write(
+            root,
+            "pom.xml",
+            r#"<project><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version>
+            <packaging>pom</packaging><modules><module>lib</module><module>app</module></modules></project>"#,
+        );
+        write(
+            root,
+            "lib/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>lib</artifactId></project>"#,
+        );
+        write(
+            root,
+            "app/pom.xml",
+            r#"<project><parent><groupId>demo</groupId><artifactId>parent</artifactId><version>1</version></parent>
+            <artifactId>app</artifactId><dependencies><dependency><groupId>demo</groupId><artifactId>lib</artifactId><version>1</version></dependency></dependencies></project>"#,
+        );
+        write(root, "app/src/main/java/demo/Main.java", "class Main {}");
+        write(root, "app/src/test/java/demo/MainTest.java", "class MainTest {}");
+        write(root, "lib/target/classes/Lib.class", "built");
+        crate::load(root, &root.join("cache"), None)
+    }
+
+    #[test]
+    fn target_finds_the_owning_module_and_the_test_scope() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let main = single_file_target(root, &model, &root.join("app/src/main/java/demo/Main.java")).unwrap();
+        assert_eq!(main.module, root.join("app"));
+        assert!(!main.test);
+        assert_eq!(main.out_dir, root.join("app/target/classes"));
+        let test = single_file_target(root, &model, &root.join("app/src/test/java/demo/MainTest.java")).unwrap();
+        assert!(test.test);
+        assert_eq!(test.out_dir, root.join("app/target/test-classes"));
+    }
+
+    #[test]
+    fn target_rejects_non_java_missing_and_unlinked_files() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        write(root, "app/pom.xml", "<project/>");
+        assert!(single_file_target(root, &model, &root.join("app/pom.xml")).is_err());
+        assert!(single_file_target(root, &model, &root.join("app/src/main/java/demo/Missing.java")).is_err());
+        write(root, "other/Main.java", "class Main {}");
+        assert!(single_file_target(root, &model, &root.join("other/Main.java")).is_err());
+    }
+
+    #[test]
+    fn javac_prefers_the_module_jdk_and_scopes_test_sources() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let file = root.join("app/src/test/java/demo/MainTest.java");
+        let target = single_file_target(root, &model, &file).unwrap();
+        let jdk = root.join("jdk");
+        fs::create_dir_all(jdk.join("bin")).unwrap();
+        let exe = if cfg!(windows) { "javac.exe" } else { "javac" };
+        fs::write(jdk.join("bin").join(exe), "fake").unwrap();
+        let mut target = target;
+        target.top.env.insert("JAVA_HOME".into(), jdk.to_string_lossy().into_owned());
+        let step = javac_step(&target, &file, "/repo/a.jar", &find_javac(&target.top.env)).unwrap();
+        assert!(step.program.ends_with(exe));
+        assert!(target.out_dir.is_dir());
+        let args = step.args.join(" ");
+        assert!(args.contains("-encoding UTF-8"), "{args}");
+        assert!(args.contains("-d ") && args.contains("test-classes"), "{args}");
+        assert!(args.contains("-cp /repo/a.jar"), "{args}");
+        assert!(args.contains("MainTest.java"), "{args}");
+        // Test sources resolve their own and the main sources, without writing them.
+        let sourcepath = step.args.iter().position(|a| a == "-sourcepath").map(|i| step.args[i + 1].clone());
+        let roots = sourcepath.expect("a -sourcepath");
+        assert!(roots.contains("src/test/java") && roots.contains("src/main/java"), "{roots}");
+        assert!(step.args.iter().any(|a| a == "-implicit:none"), "{args}");
+        // No `JAVA_HOME`: plain `javac` from `PATH`.
+        assert_eq!(find_javac(&BTreeMap::new()), exe);
+    }
+
+    /// The classpath probe runs the project's Maven command with `-pl … -am`
+    /// `dependency:build-classpath`; the fake `mvnw` below only records its
+    /// arguments and writes a canned classpath file for the `-pl` module.
+    #[cfg(unix)]
+    #[test]
+    fn classpath_probe_writes_one_file_per_module_and_reads_the_compiled_one() {
+        use std::os::unix::fs::PermissionsExt;
+
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        fixture(root);
+        let script = root.join("mvnw");
+        fs::write(
+            &script,
+            "#!/bin/sh\npl='.'\nwhile [ $# -gt 0 ]; do\nif [ \"$1\" = \"-pl\" ]; then pl=\"$2\"; shift 2; else shift; fi\ndone\nmkdir -p \"$pl/target\"\nprintf '/repo/a.jar:/repo/b.jar' > \"$pl/target/ide-compile-cp.txt\"\n",
+        )
+        .unwrap();
+        fs::set_permissions(&script, fs::Permissions::from_mode(0o755)).unwrap();
+        let model = crate::load(root, &root.join("cache"), None);
+        let file = root.join("app/src/main/java/demo/Main.java");
+        let target = single_file_target(root, &model, &file).unwrap();
+        assert!(target.top.command.ends_with("mvnw"));
+        assert_eq!(target.pl, "app");
+        let cp = single_file_classpath(root, &model, &target).unwrap();
+        let separator = ':';
+        // Reactor class directories first, so fresh outputs shadow installed snapshots.
+        let lib = root.join("lib/target/classes").to_string_lossy().into_owned();
+        assert!(cp.starts_with(&lib), "{cp}");
+        // The module's own classes come first once they exist.
+        fs::create_dir_all(root.join("app/target/classes")).unwrap();
+        let cp = single_file_classpath(root, &model, &target).unwrap();
+        let own = root.join("app/target/classes").to_string_lossy().into_owned();
+        assert!(cp.starts_with(&format!("{own}:{lib}")), "{cp}");
+        assert!(cp.contains("/repo/a.jar"), "{cp}");
+        assert!(cp.contains("/repo/b.jar"), "{cp}");
+        assert!(cp.split(separator).count() >= 3, "{cp}");
+    }
+}

crates/ide-build/src/compile/up_to_date.rs

@@ -0,0 +1,253 @@
+//! Up-to-date checks for menu builds (`Build Project` / `Build Module`, #2476).
+//!
+//! Menu builds have no fingerprint record on the launch path, so a second
+//! click always pays a full offline Maven run. This module stores one JSON
+//! record per scope (project, or one module file's build) after a successful
+//! build and compares it before the next build; on a match the build is
+//! skipped entirely. Like launch reuse, timestamp-preserving external edits
+//! are re-stamped first so Maven actually recompiles them on the next run.
+
+use super::*;
+use std::fs;
+
+/// Record of the last successful menu build of one scope.
+#[derive(serde::Serialize, serde::Deserialize)]
+struct Record {
+    fingerprint: LaunchFingerprint,
+    /// Output folders of the built projects that existed after the build, relative to the
+    /// project. Deleting one outside the IDE (`mvn clean` in a terminal) leaves every input
+    /// unchanged, so a build is skipped only while they are all still there.
+    #[serde(default)]
+    outputs: Vec<PathBuf>,
+}
+
+/// The build's output folders that exist now, relative to `root`.
+fn existing_outputs(root: &Path, fingerprint: &LaunchFingerprint) -> Vec<PathBuf> {
+    fingerprint
+        .project_dirs()
+        .flat_map(|dir| ["target/classes", "target/test-classes"].map(|out| dir.join(out)))
+        .filter(|rel| root.join(rel).is_dir())
+        .collect()
+}
+
+fn record_path(cache: &Path, root: &Path, file: Option<&Path>) -> PathBuf {
+    let base = cache.join("menu-build").join("records");
+    match file {
+        Some(f) => base.join(f.strip_prefix(root).unwrap_or(f)).with_extension("json"),
+        None => base.join("project.json"),
+    }
+}
+
+/// Re-stamps files whose content changed without advancing mtime (git
+/// checkout, external sync): timestamp-incremental Maven would otherwise skip
+/// them as "unchanged" and the rebuild would compile nothing.
+fn restamp(root: &Path, edits: &[PathBuf]) {
+    let now = std::time::SystemTime::now();
+    for rel in edits {
+        let path = root.join(rel);
+        let _ = fs::File::options().write(true).open(&path).and_then(|f| f.set_modified(now)).or_else(|_| {
+            fs::OpenOptions::new()
+                .create(true)
+                .truncate(false)
+                .write(true)
+                .open(&path)
+                .and_then(|f| f.set_modified(now))
+        });
+    }
+}
+
+/// Whether the last successful menu build of this scope is still fresh: its
+/// record exists and the fingerprint matches. On a mismatch caused by
+/// timestamp-preserving external edits the files are re-stamped first, so the
+/// rebuild Maven runs actually recompiles them.
+pub fn menu_up_to_date(
+    cache: &Path,
+    root: &Path,
+    model: &BuildModel,
+    file: Option<&Path>,
+    cancel: &CancellationToken,
+) -> bool {
+    let current = match menu_fingerprint(root, model, file, cancel) {
+        Ok(Some(current)) => current,
+        _ => return false,
+    };
+    let bytes = match fs::read(record_path(cache, root, file)) {
+        Ok(bytes) => bytes,
+        _ => return false,
+    };
+    let record: Record = match serde_json::from_slice(&bytes) {
+        Ok(record) => record,
+        _ => return false,
+    };
+    if record.fingerprint != current {
+        restamp(root, &record.fingerprint.mtime_preserved_edits(&current));
+        return false;
+    }
+    record.outputs.iter().all(|out| root.join(out).is_dir())
+}
+
+/// Records a successful menu build as the baseline for future up-to-date
+/// checks. Failures are swallowed: a missing record only costs one Maven run.
+pub fn record_menu_build(
+    cache: &Path,
+    root: &Path,
+    model: &BuildModel,
+    file: Option<&Path>,
+    cancel: &CancellationToken,
+) {
+    let current = match menu_fingerprint(root, model, file, cancel) {
+        Ok(Some(current)) => current,
+        _ => return,
+    };
+    // A torn write fails to parse later and is treated as "no record", so a
+    // plain write is enough.
+    let path = record_path(cache, root, file);
+    if path.parent().is_some_and(|p| fs::create_dir_all(p).is_err()) {
+        return;
+    }
+    let outputs = existing_outputs(root, &current);
+    let bytes = match serde_json::to_vec(&Record { fingerprint: current, outputs }) {
+        Ok(bytes) => bytes,
+        _ => return,
+    };
+    let _ = fs::write(&path, bytes);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn write(root: &Path, rel: &str, value: &str) {
+        let path = root.join(rel);
+        fs::create_dir_all(path.parent().unwrap()).unwrap();
+        fs::write(path, value).unwrap();
+    }
+
+    fn fixture(root: &Path) -> BuildModel {
+        maven_two_module(root, "int x;");
+        BuildModel { maven: Some(maven::load(root)), ..Default::default() }
+    }
+
+    fn maven_two_module(root: &Path, extra_app: &str) {
+        write(
+            root,
+            "pom.xml",
+            r#"<project><modelVersion>4.0.0</modelVersion><groupId>t</groupId><artifactId>root</artifactId><version>1</version><packaging>pom</packaging><modules><module>app</module><module>lib</module></modules></project>"#,
+        );
+        write(
+            root,
+            "app/pom.xml",
+            r#"<project><modelVersion>4.0.0</modelVersion><parent><groupId>t</groupId><artifactId>root</artifactId><version>1</version></parent><artifactId>app</artifactId><dependencies><dependency><groupId>t</groupId><artifactId>lib</artifactId><version>1</version></dependency></dependencies></project>"#,
+        );
+        write(
+            root,
+            "lib/pom.xml",
+            r#"<project><modelVersion>4.0.0</modelVersion><parent><groupId>t</groupId><artifactId>root</artifactId><version>1</version></parent><artifactId>lib</artifactId></project>"#,
+        );
+        write(root, "app/src/main/java/t/A.java", &format!("package t; public class A {{ {extra_app} }}"));
+        write(root, "lib/src/main/java/t/L.java", "package t; public class L {}");
+    }
+
+    #[test]
+    fn record_then_skip_without_changes() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let file = root.join("app/src/main/java/t/A.java");
+        let cancel = CancellationToken::new();
+
+        assert!(!menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+        record_menu_build(&cache, root, &model, Some(&file), &cancel);
+        assert!(menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+        // The project scope is independent of the module scope.
+        assert!(!menu_up_to_date(&cache, root, &model, None, &cancel));
+        record_menu_build(&cache, root, &model, None, &cancel);
+        assert!(menu_up_to_date(&cache, root, &model, None, &cancel));
+    }
+
+    #[test]
+    fn deleted_outputs_invalidate_the_record() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let cancel = CancellationToken::new();
+        for out in ["app/target/classes/t", "lib/target/classes/t", "app/target/test-classes"] {
+            fs::create_dir_all(root.join(out)).unwrap();
+        }
+        record_menu_build(&cache, root, &model, None, &cancel);
+        assert!(menu_up_to_date(&cache, root, &model, None, &cancel));
+        // `mvn clean` outside the IDE: no input changed, but the classes are gone.
+        fs::remove_dir_all(root.join("lib/target")).unwrap();
+        assert!(!menu_up_to_date(&cache, root, &model, None, &cancel));
+        fs::create_dir_all(root.join("lib/target/classes")).unwrap();
+        assert!(menu_up_to_date(&cache, root, &model, None, &cancel));
+    }
+
+    #[test]
+    fn edit_invalidates_and_rerecord_restores_skip() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let file = root.join("app/src/main/java/t/A.java");
+        let cancel = CancellationToken::new();
+
+        record_menu_build(&cache, root, &model, Some(&file), &cancel);
+        assert!(menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+        write(root, "app/src/main/java/t/A.java", "package t; public class A { int y; }");
+        assert!(!menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+        record_menu_build(&cache, root, &model, Some(&file), &cancel);
+        assert!(menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+    }
+
+    #[test]
+    fn mtime_preserved_edit_forces_rebuild_and_restamps() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let rel = "app/src/main/java/t/A.java";
+        let file = root.join(rel);
+        let cancel = CancellationToken::new();
+
+        record_menu_build(&cache, root, &model, Some(&file), &cancel);
+        let before = fs::metadata(&file).unwrap().modified().unwrap();
+        // Same length, same mtime, different content: an external edit that
+        // preserved the timestamp.
+        write(root, rel, "package t; public class A { int z; }");
+        fs::File::options().write(true).open(&file).and_then(|f| f.set_modified(before)).unwrap();
+        assert!(!menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+        assert!(fs::metadata(&file).unwrap().modified().unwrap() > before);
+    }
+
+    #[test]
+    fn corrupt_record_never_skips() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        let cache = root.join("cache");
+        let file = root.join("app/src/main/java/t/A.java");
+        let cancel = CancellationToken::new();
+
+        fs::create_dir_all(cache.join("menu-build").join("records").join("app/src/main/java/t")).unwrap();
+        fs::write(cache.join("menu-build").join("records").join("app/src/main/java/t/A.json"), b"{not json").unwrap();
+        assert!(!menu_up_to_date(&cache, root, &model, Some(&file), &cancel));
+    }
+
+    #[test]
+    fn unsupported_builds_never_skip() {
+        let dir = tempfile::tempdir().unwrap();
+        let root = dir.path();
+        let model = fixture(root);
+        write(root, "other/Main.java", "public class Main {}");
+        let cache = root.join("cache");
+        let cancel = CancellationToken::new();
+
+        // A file outside any non-aggregator module has no fingerprint.
+        let stray = root.join("other/Main.java");
+        record_menu_build(&cache, root, &model, Some(&stray), &cancel);
+        assert!(!menu_up_to_date(&cache, root, &model, Some(&stray), &cancel));
+    }
+}

crates/ide-build/src/gradle-model.gradle

@@ -8,6 +8,24 @@ def canon = { File f -> f.canonicalPath }
 // the identity path (`:lib:core`, `:buildSrc`) tells them apart and addresses their tasks
 // from the root build. Internal API, hence the fallback.
 def identity = { Project p -> try { p.identityPath.toString() } catch (ignored) { p.path } }
+// The task copying a source set's resources and its output folder, when it changes them on the
+// way (filters, `expand`, renames, includes / excludes, extra sources): jdtls copies resources as
+// they are, so launches take them from Gradle. Internal API, hence the fallback.
+def processedResources = { Project p, s ->
+    try {
+        def task = p.tasks.findByName(s.processResourcesTaskName)
+        if (task == null) return null
+        def specs = 0
+        def changes = task.mainSpec.sourcePaths.size() > 1
+        task.rootSpec.buildRootResolver().walk { r ->
+            specs++
+            changes |= !r.allCopyActions.isEmpty() || !r.allIncludes.isEmpty() || !r.allExcludes.isEmpty() ||
+                !r.allIncludeSpecs.isEmpty() || !r.allExcludeSpecs.isEmpty() || r.destPath.segments.length > 0
+        }
+        // The root and main specs exist for every task; more come from `from(…) { … }`.
+        (changes || specs > 2) ? [task: task.name, dir: canon(task.destinationDir)] : null
+    } catch (ignored) { null }
+}
 
 def describe = { Project p ->
     def m = [path: identity(p), dir: canon(p.projectDir), buildDir: canon(p.layout.buildDirectory.get().asFile)]
@@ -26,7 +44,10 @@ def describe = { Project p ->
             def test = s.name == 'test' || s.name == 'testFixtures' || suites.contains(s.name) ||
                 s.name.endsWith('Test') || s.name.endsWith('Tests') ||
                 (!src.isEmpty() && src.every { ideaTests.contains(it) })
-            [name: s.name, test: test, src: src, res: res]
+            def set = [name: s.name, test: test, src: src, res: res]
+            def processed = processedResources(p, s)
+            if (processed != null) set.processed = processed
+            set
         }
     }
     try {

crates/ide-build/src/gradle.rs

@@ -335,6 +335,19 @@ pub struct ReportedSourceSet {
     /// Absolute resource folders.
     #[serde(default)]
     pub res: Vec<String>,
+    /// Set when Gradle changes the resources while copying them (filters, `expand`, renames,
+    /// includes / excludes, extra sources), which the Java language server's copy does not.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub processed: Option<ProcessedResources>,
+}
+
+/// The task that copies a source set's resources, and where it writes them.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct ProcessedResources {
+    /// Task name in its project (`processResources`).
+    pub task: String,
+    /// Absolute output folder.
+    pub dir: String,
 }
 
 const MODEL_LINE: &str = "@openidea-model\t";

crates/ide-build/src/kotlin_bridge.rs

@@ -528,7 +528,17 @@ mod tests {
             for (step, name) in plan.steps.iter().zip(["java", "kotlin"]) {
                 assert_eq!(step.cwd, root.join(name));
                 assert_eq!(step.program, format!("{name}-mvnw"));
-                assert_eq!(step.args, ["-B", "-Dstyle.color=never", "-o", "-Peditor", "test-compile"]);
+                assert_eq!(
+                    step.args,
+                    [
+                        "-B",
+                        "-Dstyle.color=never",
+                        crate::maven::LOCAL_REPO_TRACKING_ARG,
+                        "-o",
+                        "-Peditor",
+                        "test-compile"
+                    ]
+                );
                 assert_eq!(step.env.get("JAVA_HOME").map(String::as_str), Some("/jdk"));
             }
         }

crates/ide-build/src/maven.rs

@@ -18,6 +18,14 @@ use std::sync::{Mutex, OnceLock};
 
 pub mod sources;
 
+/// Lets the IDE's own Maven runs (Reload, Build) use what the local repository already
+/// has. Maven 3.9 re-resolves an artifact whose recorded origin repository (`_remote.repositories`)
+/// isn't declared in the build, such as a vendor jar downloaded through another project or
+/// installed by hand, and fails when no declared repository has it. Tracking under another
+/// file name makes such artifacts count as locally installed. Maven goals the user runs keep
+/// plain Maven's behaviour.
+pub const LOCAL_REPO_TRACKING_ARG: &str = "-Daether.enhancedLocalRepository.trackingFilename=openidea.repositories";
+
 /// Phases shown under "Lifecycle" (IDEA's default list).
 pub const LIFECYCLE: &[&str] =
     &["clean", "validate", "compile", "test", "package", "verify", "install", "site", "deploy"];
@@ -499,7 +507,7 @@ pub fn user_settings_file(root: &Path, settings: &ide_core::settings::MavenSetti
 /// IDEA lists them): checked by default when `<activeProfiles>` names them or they are
 /// `activeByDefault`.
 pub fn settings_profiles(settings: &Path) -> Vec<MavenProfile> {
-    let Some(root) = std::fs::read_to_string(settings).ok().and_then(|text| xml::parse(&text)) else {
+    let Some(root) = xml::read_text(settings).as_deref().and_then(xml::parse) else {
         return Vec::new();
     };
     let active: Vec<String> =
@@ -519,7 +527,7 @@ pub fn settings_profiles(settings: &Path) -> Vec<MavenProfile> {
 /// `<localRepository>` of a settings file, when it names one: the repository a build
 /// with `-s <file>` resolves into, which is not necessarily the user's default.
 pub fn local_repository_of(settings: &Path) -> Option<PathBuf> {
-    let text = std::fs::read_to_string(settings).ok()?;
+    let text = xml::read_text(settings)?;
     let root = xml::parse(&text)?;
     let repo = root.text_of("localRepository")?.trim().to_owned();
     if repo.is_empty() {
@@ -545,7 +553,7 @@ impl Resolver {
     fn pom(&mut self, path: &Path) -> Option<RawPom> {
         self.poms
             .entry(path.to_path_buf())
-            .or_insert_with(|| std::fs::read_to_string(path).ok().and_then(|t| parse_pom(&t)))
+            .or_insert_with(|| xml::read_text(path).as_deref().and_then(parse_pom))
             .clone()
     }
 
@@ -736,7 +744,7 @@ pub(crate) fn launch_inputs(
                 return None;
             }
             out.push(path.clone());
-            let text = std::fs::read_to_string(&path).ok()?;
+            let text = xml::read_text(&path)?;
             roots(&xml::parse(&text)?, "", &dir, &mut out)?;
             let raw = resolver.pom(&path)?;
             let Some(parent) = raw.parent else { break };
@@ -1640,7 +1648,7 @@ fn parent_chain(path: &Path, text: &str, local_repo: Option<PathBuf>) -> Vec<(Pa
         let Some(parent) = pom.and_then(|p| p.parent) else { return chain };
         let Some(pp) = resolver.parent_path(&dir, &parent) else { return chain };
         let pp = dunce::canonicalize(&pp).unwrap_or(pp);
-        let Ok(next) = std::fs::read_to_string(&pp) else { return chain };
+        let Some(next) = xml::read_text(&pp) else { return chain };
         pom = resolver.pom(&pp);
         dir = pp.parent().unwrap_or(Path::new("")).to_path_buf();
         chain.push((pp, next));
@@ -2297,6 +2305,24 @@ mod tests {
         assert!(!is_maven_project(&root.join("c")));
     }
 
+    #[test]
+    fn non_utf8_pom_with_declared_encoding_is_a_build() {
+        // Issue #2439: a GBK `pom.xml` is not valid UTF-8; it must still load
+        // instead of vanishing as "No maven project".
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let (bytes, _, _) = encoding_rs::GBK.encode(
+            "<?xml version=\"1.0\" encoding=\"GBK\"?>\n<project><groupId>g</groupId>\
+             <artifactId>应用</artifactId><version>1</version><name>演示</name></project>",
+        );
+        std::fs::write(root.join("pom.xml"), bytes.as_ref()).unwrap();
+        let model = load_with_repo(root, None);
+        assert_eq!(model.projects.len(), 1);
+        assert_eq!(model.projects[0].artifact_id, "应用");
+        assert_eq!(model.projects[0].display_name, "演示");
+        assert!(is_maven_project(root));
+    }
+
     #[test]
     fn aggregate_pom_in_src_is_a_build() {
         // Issue #1001: `src/pom.xml` aggregating modules under `src/` is recognized,

crates/ide-build/src/sync.rs

@@ -73,6 +73,9 @@ struct GradleCache {
     /// The projects as Gradle evaluated them; empty in caches from before they were read.
     #[serde(default)]
     projects: Vec<ReportedProject>,
+    /// The projects report how their resources are processed; older caches are stale.
+    #[serde(default)]
+    resources: bool,
 }
 
 /// Init script printing every project, its source sets and Java version once configured.
@@ -244,11 +247,12 @@ pub fn apply_gradle_cache(root: &Path, cache_dir: &Path, model: &mut GradleModel
             }
         }
     }
-    // A successful sync from before projects were cached has not seen computed includes.
-    let without_projects = cache.error.is_none() && cache.projects.is_empty();
+    // A successful sync from before projects were cached has not seen computed includes,
+    // nor, before resources were read, which launches need Gradle to process them.
+    let outdated = cache.error.is_none() && (cache.projects.is_empty() || !cache.resources);
     model.synced_at = Some(cache.at_ms);
     model.sync_error = cache.error;
-    model.stale = without_projects || cache.hash != hash_gradle_files(&gradle::build_files(root, model));
+    model.stale = outdated || cache.hash != hash_gradle_files(&gradle::build_files(root, model));
 }
 
 // ---------------------------------------------------------------- processes
@@ -341,7 +345,13 @@ pub fn sync_maven(
         // `-T1` keeps mvnd serial: its default parallel build interleaves the
         // `dependency:tree` output of concurrent modules, which the sync parses
         // as one stream. mvn is serial anyway, so this only pins the daemon.
-        let mut args: Vec<String> = vec!["-B".into(), "-fae".into(), "-Dstyle.color=never".into(), "-T1".into()];
+        let mut args: Vec<String> = vec![
+            "-B".into(),
+            "-fae".into(),
+            "-Dstyle.color=never".into(),
+            "-T1".into(),
+            maven::LOCAL_REPO_TRACKING_ARG.into(),
+        ];
         args.extend(sync_maven_options(&options.maven_options));
         if options.offline {
             args.push("-o".into());
@@ -456,6 +466,7 @@ pub fn sync_gradle_model(
         error: (!out.success).then(|| error_summary(&out.text)),
         tasks: if out.success { gradle::parse_tasks(&out.text) } else { Vec::new() },
         projects,
+        resources: true,
     };
     write_cache(&cache_dir, GRADLE_CACHE, &cache)
 }
@@ -707,6 +718,7 @@ mod tests {
             test,
             src: src.iter().map(|p| core_src(p)).collect(),
             res: res.iter().map(|p| core_src(p)).collect(),
+            processed: None,
         };
         // A settings script's own println comes first; task listing lines follow.
         let out = format!(
@@ -731,6 +743,15 @@ mod tests {
         );
         let projects = parse_reported_projects(&out);
         assert_eq!(projects.len(), 3, "the malformed line is skipped");
+        // As the init script prints a set whose resources Gradle filters or renames.
+        let processed = parse_reported_projects(&format!(
+            "@openidea-model\t{}",
+            r#"{"path":":","dir":"/p","sourceSets":[{"name":"main","test":false,"src":[],"res":[],"processed":{"task":"processResources","dir":"/p/build/resources/main"}}]}"#
+        ));
+        assert_eq!(
+            processed[0].source_sets[0].processed,
+            Some(gradle::ProcessedResources { task: "processResources".into(), dir: "/p/build/resources/main".into() })
+        );
         let src = |p: &str| PathBuf::from(core_src(p));
         assert_eq!(
             gradle::reported_source_roots(&projects),
@@ -796,12 +817,18 @@ mod tests {
                     ..Default::default()
                 })
                 .collect(),
+            resources: true,
         };
         write_cache(&cache_dir, GRADLE_CACHE, &cache).unwrap();
         apply_gradle_cache(&root, &cache_dir, &mut model);
         assert_eq!(model.projects[1].tasks.len(), 1);
         assert!(model.projects[0].tasks.iter().any(|t| t.name == "wrapper"), "root keeps its defaults");
         assert!(!model.stale);
+        write_cache(&cache_dir, GRADLE_CACHE, &GradleCache { resources: false, ..cache.clone() }).unwrap();
+        let mut m = gradle::load(&root).unwrap();
+        apply_gradle_cache(&root, &cache_dir, &mut m);
+        assert!(m.stale, "synced before resource processing was read");
+        write_cache(&cache_dir, GRADLE_CACHE, &cache).unwrap();
 
         let stale_after = |script: &str| {
             std::fs::write(root.join("app/build.gradle"), script).unwrap();
@@ -835,6 +862,7 @@ mod tests {
                 dir: root.to_string_lossy().into_owned(),
                 ..Default::default()
             }],
+            resources: true,
             ..Default::default()
         };
         write_cache(&cache_dir, GRADLE_CACHE, &cache).unwrap();

crates/ide-build/src/xml.rs

@@ -3,6 +3,57 @@
 //! skipped. Namespace prefixes are dropped (`<x:project>` → `project`).
 //! Elements keep their byte offsets in the source, for edits ([`crate::pom_edit`]).
 
+use encoding_rs::Encoding;
+use std::path::Path;
+
+/// Reads an XML file, honoring its `encoding="…"` declaration: a GBK POM
+/// (issue #2439) is not valid UTF-8, and `read_to_string` would drop the
+/// whole project as "No maven project" while CLI Maven reads it fine.
+pub fn read_text(path: &Path) -> Option<String> {
+    std::fs::read(path).ok().map(|bytes| decode_bytes(&bytes))
+}
+
+/// Decodes XML bytes: BOM first, then the `encoding` declaration (ASCII in
+/// every single-byte encoding, so the head scans before decoding), then
+/// UTF-8, then a chardetng guess.
+pub fn decode_bytes(bytes: &[u8]) -> String {
+    if let Some((enc, len)) = Encoding::for_bom(bytes) {
+        let (text, _) = enc.decode_without_bom_handling(&bytes[len..]);
+        return text.into_owned();
+    }
+    if let Some(enc) = declared_encoding(bytes) {
+        let (text, _) = enc.decode_without_bom_handling(bytes);
+        return text.into_owned();
+    }
+    if let Ok(text) = std::str::from_utf8(bytes) {
+        return text.to_owned();
+    }
+    let mut detector = chardetng::EncodingDetector::new();
+    detector.feed(bytes, true);
+    let (text, _) = detector.guess(None, true).decode_without_bom_handling(bytes);
+    text.into_owned()
+}
+
+fn declared_encoding(bytes: &[u8]) -> Option<&'static Encoding> {
+    let head = std::str::from_utf8(bytes.get(..bytes.len().min(1024))?).ok()?;
+    let mut rest = head.split("?>").next().unwrap_or(head);
+    while let Some(i) = rest.find("encoding") {
+        rest = &rest[i + "encoding".len()..];
+        let Some(value) = rest.trim_start().strip_prefix('=') else { continue };
+        let value = value.trim_start();
+        let (&quote, after) = value.as_bytes().split_first()?;
+        if quote != b'"' && quote != b'\'' {
+            continue;
+        }
+        let after = std::str::from_utf8(after).ok()?;
+        let end = after.find(quote as char)?;
+        if let Some(enc) = Encoding::for_label(after[..end].trim().as_bytes()) {
+            return Some(enc);
+        }
+    }
+    None
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Eq)]
 pub struct Element {
     pub name: String,
@@ -210,4 +261,19 @@ mod tests {
         assert!(parse("").is_none());
         assert!(parse("just text").is_none());
     }
+
+    #[test]
+    fn decodes_the_declared_encoding() {
+        // Issue #2439: a GBK POM is not valid UTF-8; decoding must honor the declaration.
+        let (bytes, _, _) =
+            encoding_rs::GBK.encode("<?xml version=\"1.0\" encoding=\"GBK\"?>\n<project><name>中文</name></project>");
+        let text = decode_bytes(&bytes);
+        assert_eq!(parse(&text).unwrap().text_of("name").as_deref(), Some("中文"));
+        // An unknown label falls back to UTF-8 rather than mis-decoding.
+        let text = decode_bytes(b"<?xml version=\"1.0\" encoding=\"X-UNKNOWN\"?>\n<project><name>ok</name></project>");
+        assert_eq!(parse(&text).unwrap().text_of("name").as_deref(), Some("ok"));
+        // No declaration: plain UTF-8 passes through untouched.
+        let text = decode_bytes("<project><name>plain</name></project>".as_bytes());
+        assert_eq!(parse(&text).unwrap().text_of("name").as_deref(), Some("plain"));
+    }
 }

crates/ide-core/Cargo.toml

@@ -7,7 +7,6 @@ license.workspace = true
 
 [dependencies]
 dunce.workspace = true
-percent-encoding = "2"
 encoding_rs.workspace = true
 serde.workspace = true
 serde_json.workspace = true

crates/ide-core/src/editor_settings.rs

@@ -73,6 +73,8 @@ pub struct EditorAppearanceSettings {
     pub whitespace_inner: bool,
     pub whitespace_trailing: bool,
     pub indent_guides: bool,
+    /// Colour indent guides by depth (`--syn-rainbow-*`), while `indent_guides` is on.
+    pub rainbow_indent_guides: bool,
     /// Right margin and visual guides from Code Style.
     pub hard_wrap_guides: bool,
     pub intention_bulb: bool,
@@ -95,6 +97,7 @@ impl Default for EditorAppearanceSettings {
             whitespace_inner: true,
             whitespace_trailing: true,
             indent_guides: true,
+            rainbow_indent_guides: false,
             hard_wrap_guides: true,
             intention_bulb: true,
             distraction_free_width: 80,
@@ -330,6 +333,23 @@ pub struct InlayHintsSettings {
     pub code_vision_usages: bool,
     /// Code vision: last author of a declaration (VCS blame) beside its usages.
     pub code_vision_author: bool,
+    /// Code vision: "no usages" on declarations nothing uses (IDEA shows it; clicking searches everywhere).
+    pub code_vision_no_usages: bool,
+    /// Code vision: where the usages go, above the declaration or at the end of its line.
+    pub code_vision_usages_position: CodeVisionPosition,
+    /// Code vision: where the author goes, above the declaration or at the end of its line.
+    pub code_vision_author_position: CodeVisionPosition,
+}
+
+/// Editor › Inlay Hints › Code Vision position (IDEA's "Default position for metrics").
+#[derive(Clone, Copy, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum CodeVisionPosition {
+    /// A row of its own above the declaration.
+    #[default]
+    Top,
+    /// After the end of the declaration's first line.
+    Right,
 }
 
 impl Default for InlayHintsSettings {
@@ -341,6 +361,9 @@ impl Default for InlayHintsSettings {
             disabled_languages: Vec::new(),
             code_vision_usages: true,
             code_vision_author: true,
+            code_vision_no_usages: true,
+            code_vision_usages_position: CodeVisionPosition::Top,
+            code_vision_author_position: CodeVisionPosition::Top,
         }
     }
 }

crates/ide-core/src/event.rs

@@ -273,6 +273,27 @@ pub enum DebugEvent {
         change_type: String,
         message: String,
     },
+    /// The session's capabilities changed after it started: fetch them again.
+    Capabilities,
+    JvmBackend {
+        state: JvmBackendState,
+    },
+}
+
+/// The backend that reads a debugged JVM's objects (instances, fields, referrers).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "kind", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmBackendState {
+    Ready,
+    /// Turned off for the rest of the session: the debug adapter lacks what it needs.
+    Unsupported {
+        detail: String,
+    },
+    /// The Kotlin JDWP link only forwards now; inspecting stops.
+    Degraded {
+        detail: String,
+    },
+    Closed,
 }
 
 /// Where backend crates publish [`IdeEvent`]s. Cheap to clone via `Arc`.
@@ -294,3 +315,19 @@ pub struct NullSink;
 impl EventSink for NullSink {
     fn emit(&self, _: IdeEvent) {}
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde_json::json;
+
+    #[test]
+    fn jvm_backend_events_json_shape() {
+        let degraded = DebugEvent::JvmBackend { state: JvmBackendState::Degraded { detail: "x".into() } };
+        assert_eq!(
+            serde_json::to_value(&degraded).unwrap(),
+            json!({"kind": "jvmBackend", "state": {"kind": "degraded", "detail": "x"}})
+        );
+        assert_eq!(serde_json::to_value(DebugEvent::Capabilities).unwrap(), json!({"kind": "capabilities"}));
+    }
+}

crates/ide-core/src/lib.rs

@@ -16,7 +16,6 @@ pub mod ipc_path;
 pub mod java_runtime;
 pub mod jsonc;
 pub mod output_encoding;
-pub mod path_mapping;
 pub mod platform;
 pub mod process;
 pub mod project_dir;

crates/ide-core/src/output_encoding.rs

@@ -21,6 +21,32 @@
 
 use std::collections::BTreeMap;
 
+/// Removes ANSI escape sequences (colour, cursor movement).
+pub fn strip_ansi(s: &str) -> String {
+    if !s.contains('\u{1b}') {
+        return s.to_owned();
+    }
+    let mut out = String::with_capacity(s.len());
+    let mut chars = s.chars().peekable();
+    while let Some(c) = chars.next() {
+        if c != '\u{1b}' {
+            out.push(c);
+            continue;
+        }
+        if chars.peek() == Some(&'[') {
+            chars.next();
+            for c in chars.by_ref() {
+                if c.is_ascii_alphabetic() || c == '~' {
+                    break;
+                }
+            }
+        } else {
+            chars.next();
+        }
+    }
+    out
+}
+
 /// Decodes complete lines or collected output from IDE-managed tools, preferring UTF-8.
 /// Windows launcher/native diagnostics fall back to the system ANSI code page.
 /// Callers must buffer incomplete lines so multibyte characters are never split.

crates/ide-core/src/path_mapping.rs

@@ -1,193 +0,0 @@
-//! Lexical path translation at protocol boundaries, independent of LSP or DAP.
-use percent_encoding::{CONTROLS, percent_decode_str, utf8_percent_encode};
-use serde_json::Value;
-
-const ESCAPES: &percent_encoding::AsciiSet = &CONTROLS
-    .add(b' ')
-    .add(b'"')
-    .add(b'#')
-    .add(b'%')
-    .add(b'<')
-    .add(b'>')
-    .add(b'?')
-    .add(b'[')
-    .add(b']')
-    .add(b'\\')
-    .add(b'^')
-    .add(b'`')
-    .add(b'{')
-    .add(b'|')
-    .add(b'}');
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub struct PathMapping {
-    host: String,
-    target: String,
-    windows: bool,
-}
-
-#[derive(Clone, Copy)]
-pub enum Direction {
-    ToTarget,
-    ToHost,
-}
-
-fn normalized(path: &str) -> String {
-    let path = path
-        .strip_prefix(r"\\?\UNC\")
-        .map(|p| format!("//{p}"))
-        .unwrap_or_else(|| path.strip_prefix(r"\\?\").unwrap_or(path).to_owned());
-    let path = path.replace('\\', "/");
-    if path == "/" { path } else { path.trim_end_matches('/').to_owned() }
-}
-
-pub fn file_path(uri: &str) -> Option<String> {
-    if !uri.get(..7)?.eq_ignore_ascii_case("file://") {
-        return None;
-    }
-    let rest = &uri[7..];
-    let path = if rest.starts_with('/') {
-        rest.to_owned()
-    } else {
-        let (authority, path) = rest.split_once('/')?;
-        if authority.eq_ignore_ascii_case("localhost") { format!("/{path}") } else { format!("//{authority}/{path}") }
-    };
-    let decoded = percent_decode_str(path.split(['?', '#']).next()?).decode_utf8().ok()?;
-    let path = decoded.strip_prefix('/').filter(|p| p.as_bytes().get(1) == Some(&b':')).unwrap_or(&decoded);
-    Some(path.to_owned())
-}
-
-pub fn file_uri(path: &str) -> String {
-    let path = normalized(path);
-    format!("file://{}{}", if path.starts_with('/') { "" } else { "/" }, utf8_percent_encode(&path, ESCAPES))
-}
-
-impl PathMapping {
-    pub fn new(host: &str, target: &str) -> Self {
-        let host = normalized(host);
-        let windows = host.as_bytes().get(1) == Some(&b':') || host.starts_with("//");
-        Self { host, target: normalized(target), windows }
-    }
-
-    pub fn map(&self, value: &str, direction: Direction) -> Option<String> {
-        let uri_path = file_path(value);
-        let is_uri = uri_path.is_some();
-        let path = normalized(uri_path.as_deref().unwrap_or(value));
-        let (from, to) = match direction {
-            Direction::ToTarget => (&self.host, &self.target),
-            Direction::ToHost => (&self.target, &self.host),
-        };
-        let prefix = path.get(..from.len())?;
-        let same = if self.windows && matches!(direction, Direction::ToTarget) {
-            prefix.eq_ignore_ascii_case(from)
-        } else {
-            prefix == from
-        };
-        if !same {
-            return None;
-        }
-        let suffix = &path[from.len()..];
-        if !suffix.is_empty() && !suffix.starts_with('/') && from != "/" {
-            return None;
-        }
-        // Never let lexical parent segments escape either mapped root.
-        if suffix.split('/').any(|p| p == ".." || p == ".") {
-            return None;
-        }
-        let mapped = format!("{}/{}", to.trim_end_matches('/'), suffix.trim_start_matches('/'));
-        let mapped = if suffix.is_empty() { to.clone() } else { mapped };
-        Some(if is_uri {
-            let suffix = value.find(['?', '#']).map(|i| &value[i..]).unwrap_or("");
-            format!("{}{suffix}", file_uri(&mapped))
-        } else if self.windows && matches!(direction, Direction::ToHost) {
-            mapped.replace('/', "\\")
-        } else {
-            mapped
-        })
-    }
-
-    pub fn rewrite(&self, value: &mut Value, direction: Direction) {
-        rewrite_strings(value, &|s| self.map(s, direction));
-    }
-}
-
-/// Rewrites strings and object keys (WorkspaceEdit.changes uses URIs as keys).
-/// Resolve tokens and command arguments remain opaque; source text is never a path.
-pub fn rewrite_strings(value: &mut Value, map: &dyn Fn(&str) -> Option<String>) {
-    match value {
-        Value::String(s) => {
-            if let Some(mapped) = map(s) {
-                *s = mapped;
-            }
-        }
-        Value::Array(items) => items.iter_mut().for_each(|v| rewrite_strings(v, map)),
-        Value::Object(fields) => {
-            let old = std::mem::take(fields);
-            for (key, mut value) in old {
-                if !matches!(key.as_str(), "data" | "arguments" | "text" | "newText" | "insertText") {
-                    rewrite_strings(&mut value, map);
-                }
-                fields.insert(map(&key).unwrap_or(key), value);
-            }
-        }
-        _ => {}
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use serde_json::json;
-
-    #[test]
-    fn roots_encoding_boundaries_and_windows() {
-        for host in ["C:/Users/me/项目", r"C:\Users\me\项目", r"\\?\C:\Users\me\项目"] {
-            let m = PathMapping::new(host, "/app");
-            assert_eq!(m.map(r"\\?\c:\Users\me\项目\a b#%.php", Direction::ToTarget).unwrap(), "/app/a b#%.php");
-            assert_eq!(
-                m.map("file:///C:/Users/me/%E9%A1%B9%E7%9B%AE/a%20b%23%25.php", Direction::ToTarget).unwrap(),
-                "file:///app/a%20b%23%25.php"
-            );
-            assert_eq!(
-                m.map("file:///app/a%20b%23%25.php", Direction::ToHost).unwrap(),
-                "file:///C:/Users/me/%E9%A1%B9%E7%9B%AE/a%20b%23%25.php"
-            );
-            assert_eq!(m.map("/app/a.php", Direction::ToHost).unwrap(), r"C:\Users\me\项目\a.php");
-            for outside in ["/app2/a", "/vendor/a", "/app/../outside", "jdt://app/a"] {
-                assert!(m.map(outside, Direction::ToHost).is_none());
-            }
-        }
-        let unc = PathMapping::new(r"\\?\UNC\server\share\project", "/app");
-        assert_eq!(unc.map("file://server/share/project/a.php", Direction::ToTarget).unwrap(), "file:///app/a.php");
-        assert_eq!(unc.map("/app/a.php", Direction::ToHost).unwrap(), r"\\server\share\project\a.php");
-        let m = PathMapping::new("/home/me/project", "/app");
-        assert_eq!(m.map("/home/me/project", Direction::ToTarget).unwrap(), "/app");
-        assert_eq!(m.map("file://localhost/app/a", Direction::ToHost).unwrap(), "file:///home/me/project/a");
-        assert!(m.map("/home/me/project2/a", Direction::ToTarget).is_none());
-        assert_eq!(
-            m.map("file:///app/a%23b?query#fragment", Direction::ToHost).unwrap(),
-            "file:///home/me/project/a%23b?query#fragment"
-        );
-    }
-
-    #[test]
-    fn nested_messages_resource_operations_and_opaque_payloads() {
-        let m = PathMapping::new("/host/project", "/app");
-        let mut v = json!({"rootUri":"file:///host/project", "rootPath":"/host/project", "workspaceFolders":[{"uri":"file:///host/project"}],
-            "edit":{"changes":{"file:///host/project/a":[]}, "documentChanges":[{"oldUri":"file:///host/project/a", "newUri":"file:///host/project/b"}]},
-            "relatedInformation":[{"location":{"uri":"file:///host/project/a"}}], "target":"file:///host/project/b",
-            "configuration":[{"includePath":"/host/project/vendor"}], "text":"/host/project/a", "newText":"/host/project/b", "data":{"uri":"file:///host/project/a"}, "command":{"arguments":["/host/project/a"]}});
-        let original = v.clone();
-        m.rewrite(&mut v, Direction::ToTarget);
-        assert_eq!(v["rootUri"], "file:///app");
-        assert_eq!(v["rootPath"], "/app");
-        assert!(v["edit"]["changes"].get("file:///app/a").is_some());
-        assert_eq!(v["edit"]["documentChanges"][0]["newUri"], "file:///app/b");
-        assert_eq!(v["relatedInformation"][0]["location"]["uri"], "file:///app/a");
-        assert_eq!(v["configuration"][0]["includePath"], "/app/vendor");
-        assert_eq!(v["data"], original["data"]);
-        assert_eq!(v["command"], original["command"]);
-        m.rewrite(&mut v, Direction::ToHost);
-        assert_eq!(v, original);
-    }
-}

crates/ide-core/src/process.rs

@@ -72,6 +72,75 @@ pub fn kill_tree_of(pid: u32) {
     let _ = pid;
 }
 
+/// Whether a process with this id exists. PID reuse makes this conservative: a reused id keeps
+/// whatever was tied to the old process alive, a live process is never reported dead.
+pub fn process_alive(pid: u32) -> bool {
+    // `kill(0, 0)` would signal the caller's own process group.
+    if pid == 0 {
+        return false;
+    }
+    #[cfg(unix)]
+    {
+        // Above `i32::MAX` the id would wrap to a negative value, which `kill` reads as a group.
+        let Ok(pid) = libc::pid_t::try_from(pid) else { return false };
+        // SAFETY: signal 0 delivers nothing; it only checks that the process exists and is reachable.
+        unsafe { libc::kill(pid, 0) == 0 || std::io::Error::last_os_error().raw_os_error() == Some(libc::EPERM) }
+    }
+    #[cfg(windows)]
+    {
+        use std::os::windows::io::{AsRawHandle, FromRawHandle, OwnedHandle};
+        use windows_sys::Win32::Foundation::{ERROR_ACCESS_DENIED, GetLastError, STILL_ACTIVE};
+        use windows_sys::Win32::System::Threading::{
+            GetExitCodeProcess, OpenProcess, PROCESS_QUERY_LIMITED_INFORMATION,
+        };
+
+        // SAFETY: plain call; a non-null result is a process handle owned by this function.
+        let handle = unsafe { OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, 0, pid) };
+        if handle.is_null() {
+            // A process we may not open still exists.
+            // SAFETY: reads the thread's last error, set by the call above.
+            return unsafe { GetLastError() } == ERROR_ACCESS_DENIED;
+        }
+        // SAFETY: `handle` is valid and nobody else owns it.
+        let handle = unsafe { OwnedHandle::from_raw_handle(handle) };
+        let mut code = 0u32;
+        // SAFETY: a live process handle opened with query access; one out-parameter.
+        let ok = unsafe { GetExitCodeProcess(handle.as_raw_handle(), &mut code) };
+        // A handle that cannot be queried is not evidence that the process is gone.
+        ok == 0 || code == STILL_ACTIVE as u32
+    }
+    #[cfg(not(any(unix, windows)))]
+    {
+        true
+    }
+}
+
+/// The program and everything it started: an adapter may report the launcher shell, whose
+/// child is the debugged program, so stopping only the reported pid leaves the program alive.
+#[cfg(unix)]
+pub fn process_tree(pid: i32) -> Vec<i32> {
+    use std::collections::HashMap;
+    let Ok(out) = std::process::Command::new("ps").args(["-A", "-o", "pid=,ppid="]).output() else {
+        return vec![pid];
+    };
+    let mut children: HashMap<i32, Vec<i32>> = HashMap::new();
+    for line in String::from_utf8_lossy(&out.stdout).lines() {
+        let mut it = line.split_whitespace();
+        let (Some(p), Some(parent)) = (it.next(), it.next()) else { continue };
+        let (Ok(p), Ok(parent)) = (p.parse::<i32>(), parent.parse::<i32>()) else { continue };
+        children.entry(parent).or_default().push(p);
+    }
+    let mut tree = vec![pid];
+    let mut at = 0;
+    while at < tree.len() {
+        if let Some(kids) = children.get(&tree[at]) {
+            tree.extend(kids.iter().copied());
+        }
+        at += 1;
+    }
+    tree
+}
+
 /// [`kill_tree`] that first asks the group to exit: `SIGTERM`, then `grace`, then `SIGKILL`.
 /// Git removes its `index.lock` on `SIGTERM`, where `SIGKILL` leaves it behind and the next
 /// git command fails. Windows has no such signal to send from outside the child's console,
@@ -730,6 +799,30 @@ fn append_path_entries(path: &OsStr, extra: &OsStr) -> OsString {
 mod tests {
     use super::*;
 
+    #[test]
+    fn process_alive_tells_live_from_dead_pids() {
+        assert!(process_alive(std::process::id()));
+        assert!(!process_alive(0));
+        let mut cmd = if cfg!(windows) {
+            let mut cmd = Command::new("cmd");
+            cmd.args(["/C", "exit 0"]);
+            cmd
+        } else {
+            Command::new("true")
+        };
+        let mut child = cmd.spawn().unwrap();
+        let pid = child.id();
+        child.wait().unwrap();
+        drop(child);
+        assert!(!process_alive(pid));
+    }
+
+    #[cfg(unix)]
+    #[test]
+    fn process_alive_rejects_ids_that_are_not_a_single_process() {
+        assert!(!process_alive(u32::MAX));
+    }
+
     #[cfg(unix)]
     #[test]
     fn kill_tree_of_reaches_what_the_child_started() {
@@ -1050,6 +1143,25 @@ mod tests {
         }
         assert_eq!(find_executable("nope", &search), None);
     }
+
+    #[cfg(unix)]
+    #[test]
+    fn process_tree_lists_the_child_of_a_shell() {
+        let mut cmd = Command::new("sh");
+        own_group(&mut cmd).args(["-c", "sleep 5 & wait"]);
+        let mut child = cmd.spawn().unwrap();
+        let sh_pid = child.id() as i32;
+        // The shell forks `sleep` after it starts, so the tree grows a moment later.
+        let deadline = std::time::Instant::now() + Duration::from_secs(2);
+        let mut tree = process_tree(sh_pid);
+        while tree.len() < 2 && std::time::Instant::now() < deadline {
+            std::thread::sleep(Duration::from_millis(20));
+            tree = process_tree(sh_pid);
+        }
+        kill_tree(&mut child);
+        assert_eq!(tree[0], sh_pid, "the pid itself comes first");
+        assert!(tree.len() >= 2 && tree[1..].iter().all(|p| *p != sh_pid), "the shell's child follows: {tree:?}");
+    }
 }
 
 #[cfg(all(test, unix))]

crates/ide-core/src/settings.rs

@@ -48,8 +48,6 @@ pub struct Settings {
     /// Per language server, by name (`rust-analyzer`): launch and protocol
     /// options on top of the language definition, or a server defined here.
     pub language_servers: BTreeMap<String, LanguageServerSettings>,
-    /// Project language id → server and plugin target. Empty target uses the host.
-    pub language_server_targets: BTreeMap<String, LanguageServerTarget>,
     /// Editor › Inspections profiles.
     pub inspections: InspectionSettings,
     /// Editor › Natural Languages › Spelling.
@@ -61,16 +59,16 @@ pub struct Settings {
     /// Build, Execution, Deployment › Run Targets.
     pub run_targets: Vec<RunTarget>,
     pub cmake: CMakeSettings,
-    /// Tools › Agents › Chat.
+    /// Settings › Agents.
     pub agents: AgentSettings,
-    /// Tools › MCP Server (global only).
+    /// Agents › MCP Server (global only).
     pub mcp_server: McpServerSettings,
     /// Plugin settings (`[contributes.settings]`): plugin id → its values by key.
     #[specta(type = BTreeMap<String, BTreeMap<String, specta_typescript::Unknown>>)]
     pub plugins: BTreeMap<String, serde_json::Map<String, serde_json::Value>>,
 }
 
-/// What the meters in an agent task's header show.
+/// Settings › Agents: what the conversation shows and how messages are sent.
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct AgentSettings {
@@ -82,20 +80,190 @@ pub struct AgentSettings {
     pub show_usage_limits: bool,
     /// What the session has cost so far, as the agent reports it.
     pub show_cost: bool,
+    /// A finished turn's work folds into one line under its message, leaving the reply.
+    pub fold_turns: bool,
+    /// Streaming text is revealed at a steady pace rather than chunk by chunk.
+    pub smooth_text: bool,
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = ThinkingDisplay)]
+    pub thinking: ThinkingDisplay,
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = ToolCallDisplay)]
+    pub tool_calls: ToolCallDisplay,
+    /// A tool call's output (a command's, a diff) is shown without opening it.
+    pub expand_tool_output: bool,
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = SendKey)]
+    pub send_with: SendKey,
+    /// What sending does while the agent works: queue the message for after the turn, or
+    /// send it into the turn.
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = WhileRunning)]
+    pub while_running: WhileRunning,
+    /// Settings new tasks of an agent start with: agent id → option id → value.
+    #[serde(deserialize_with = "agent_defaults")]
+    #[specta(type = BTreeMap<String, BTreeMap<String, String>>)]
+    pub defaults: BTreeMap<String, BTreeMap<String, String>>,
+    /// MCP servers passed to coding agents in `session/new`, `session/load` and `session/fork`,
+    /// keyed by server name (`[agents.mcpServers.<name>]`).
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = BTreeMap<String, AgentMcpServer>)]
+    pub mcp_servers: BTreeMap<String, AgentMcpServer>,
 }
 
 impl Default for AgentSettings {
     fn default() -> Self {
-        Self { show_context_usage: true, show_work_time: true, show_usage_limits: true, show_cost: false }
+        Self {
+            show_context_usage: true,
+            show_work_time: true,
+            show_usage_limits: true,
+            show_cost: false,
+            fold_turns: true,
+            smooth_text: true,
+            thinking: ThinkingDisplay::Auto,
+            tool_calls: ToolCallDisplay::Grouped,
+            expand_tool_output: false,
+            send_with: SendKey::Enter,
+            while_running: WhileRunning::Queue,
+            defaults: BTreeMap::new(),
+            mcp_servers: BTreeMap::new(),
+        }
     }
 }
 
-/// Tools › MCP Server: agents use the IDE's built-in tools.
+/// Transport of an MCP server configured in Settings › Agents › MCP Servers.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum McpTransport {
+    #[default]
+    Stdio,
+    Http,
+    Sse,
+}
+
+/// An MCP server passed to coding agents in `session/new`, `session/load` and `session/fork`.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(default, rename_all = "camelCase")]
+pub struct AgentMcpServer {
+    #[serde(deserialize_with = "or_default")]
+    #[specta(type = McpTransport)]
+    pub transport: McpTransport,
+    pub enabled: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[specta(optional)]
+    pub command: Option<String>,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub args: Vec<String>,
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub env: BTreeMap<String, String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    #[specta(optional)]
+    pub url: Option<String>,
+    #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
+    pub headers: BTreeMap<String, String>,
+    /// Agent provider ids this server is enabled for (e.g. `["claude", "codex"]`);
+    /// empty means enabled for all agents.
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub agents: Vec<String>,
+}
+
+impl Default for AgentMcpServer {
+    fn default() -> Self {
+        Self {
+            transport: McpTransport::Stdio,
+            enabled: true,
+            command: None,
+            args: Vec::new(),
+            env: BTreeMap::new(),
+            url: None,
+            headers: BTreeMap::new(),
+            agents: Vec::new(),
+        }
+    }
+}
+
+/// A hand-edited value these settings don't know reads as the default, rather than
+/// failing the whole settings file.
+fn or_default<'de, D, T>(d: D) -> Result<T, D::Error>
+where
+    D: serde::Deserializer<'de>,
+    T: serde::de::DeserializeOwned + Default,
+{
+    Ok(serde_json::from_value(serde_json::Value::deserialize(d)?).unwrap_or_default())
+}
+
+/// [`AgentSettings::defaults`], keeping only the text values of each agent's table.
+fn agent_defaults<'de, D>(d: D) -> Result<BTreeMap<String, BTreeMap<String, String>>, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    let serde_json::Value::Object(agents) = serde_json::Value::deserialize(d)? else { return Ok(BTreeMap::new()) };
+    Ok(agents
+        .into_iter()
+        .filter_map(|(agent, options)| match options {
+            serde_json::Value::Object(options) => Some((
+                agent,
+                options
+                    .into_iter()
+                    .filter_map(|(k, v)| match v {
+                        serde_json::Value::String(v) => Some((k, v)),
+                        _ => None,
+                    })
+                    .collect(),
+            )),
+            _ => None,
+        })
+        .collect())
+}
+
+/// How the agent's reasoning shows.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ThinkingDisplay {
+    /// Open while it streams, folded once it ends.
+    #[default]
+    Auto,
+    Expanded,
+    Collapsed,
+}
+
+/// How tool calls between messages show.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum ToolCallDisplay {
+    /// A run of calls is one line saying what they did ("Read 4 files · Edited 2 files").
+    #[default]
+    Grouped,
+    /// Each call on its own line.
+    Each,
+}
+
+/// The key that sends a message; the other one starts a new line.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum SendKey {
+    #[default]
+    Enter,
+    ModEnter,
+}
+
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum WhileRunning {
+    #[default]
+    Queue,
+    Steer,
+}
+
+/// Agents › MCP Server: agents use the IDE's built-in tools.
 #[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct McpServerSettings {
     /// Serve the tools on 127.0.0.1 while the IDE runs.
     pub enabled: bool,
+    /// Run the tools that change the project or start processes without asking first
+    /// (IDEA's brave mode). Read from the IDE's own settings only, never a project's.
+    pub run_without_confirmation: bool,
 }
 
 /// Absent profiles retain automatic discovery for existing projects.
@@ -141,14 +309,6 @@ pub struct ToolSettings {
     pub path: String,
 }
 
-#[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
-#[serde(default, rename_all = "camelCase")]
-pub struct LanguageServerTarget {
-    pub target: String,
-    /// Empty selects the first configured server for the language.
-    pub server: String,
-}
-
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct LanguageServerSettings {
@@ -243,7 +403,6 @@ impl Default for Settings {
             external_tools: Vec::new(),
             tools: BTreeMap::new(),
             language_servers: BTreeMap::new(),
-            language_server_targets: BTreeMap::new(),
             inspections: InspectionSettings::default(),
             spelling: SpellingSettings::default(),
             ssh: SshSettings::default(),
@@ -297,6 +456,10 @@ pub struct GeneralSettings {
     /// Where updates come from: `auto` (the CNB mirror for the Chinese UI, else GitHub) | `github` | `cnb`.
     pub update_source: String,
     pub auto_check_updates: bool,
+    /// System Settings › Updates: open the What's New page after the app starts a new version.
+    pub show_whats_new_after_update: bool,
+    /// The version the app last started with, so the first start after an update is recognisable.
+    pub last_run_version: String,
 }
 
 impl Default for GeneralSettings {
@@ -315,6 +478,8 @@ impl Default for GeneralSettings {
             project_name: String::new(),
             update_source: "auto".into(),
             auto_check_updates: true,
+            show_whats_new_after_update: true,
+            last_run_version: String::new(),
         }
     }
 }
@@ -418,7 +583,7 @@ pub struct AppearanceSettings {
     pub project_colors_in_toolbar: bool,
     pub dnd_with_alt_only: bool,
     pub menu_icons: bool,
-    /// `hamburger` | `merged`: main menu presentation in the frameless title bar.
+    /// `hamburger` | `merged` | `toolbar` (a separate row): main menu presentation in the frameless title bar.
     pub main_menu_style: String,
     /// A lone Alt press focuses or opens the main menu (IDEA `ide.windows.main.menu.focus.on.alt`).
     pub main_menu_alt: bool,
@@ -1174,6 +1339,11 @@ pub struct ProjectStructureSettings {
     pub unmarked: Vec<String>,
     /// Content roots besides the project folder (absolute paths), shown and searched with it.
     pub content_roots: Vec<String>,
+    /// Other projects (absolute paths) this project depends on; indexed and navigable like content roots.
+    pub dependencies: Vec<String>,
+    /// Per-workspace-member dependencies: member root (IPC path) → the roots it depends on.
+    /// A member not listed here (or with an empty list) navigates only into itself.
+    pub member_dependencies: BTreeMap<String, Vec<String>>,
     /// "Exclude files": `;`-separated name patterns (`*.log;tmp*`) excluded at any depth.
     pub exclude_files: String,
     /// Project compiler output directory (relative to project root or absolute; empty = default).
@@ -1347,6 +1517,27 @@ mod tests {
         }
     }
 
+    #[test]
+    fn double_click_opens_diff_is_unset_by_default_and_round_trips() {
+        let old: Settings = serde_json::from_str(r#"{"vcs":{"commit":{"nonModal":true}}}"#).unwrap();
+        assert_eq!(old.vcs.commit.double_click_opens_diff, None);
+        // The unset value shows up as `null` in the defaults: `SettingsStore::set` only
+        // accepts a key path it finds there.
+        let json = serde_json::to_value(Settings::default()).unwrap();
+        assert_eq!(json["vcs"]["commit"]["doubleClickOpensDiff"], serde_json::Value::Null);
+        for on in [true, false] {
+            let mut settings = Settings::default();
+            settings.vcs.commit.double_click_opens_diff = Some(on);
+            let json = serde_json::to_value(&settings).unwrap();
+            assert_eq!(json["vcs"]["commit"]["doubleClickOpensDiff"], on);
+            let restored: Settings = serde_json::from_value(json).unwrap();
+            assert_eq!(restored.vcs.commit.double_click_opens_diff, Some(on));
+        }
+        // Explicit `null` reads back as unset.
+        let cleared: Settings = serde_json::from_str(r#"{"vcs":{"commit":{"doubleClickOpensDiff":null}}}"#).unwrap();
+        assert_eq!(cleared.vcs.commit.double_click_opens_diff, None);
+    }
+
     #[test]
     fn agent_meters_default_and_round_trip() {
         let old: Settings = serde_json::from_str(r#"{"agents":{"showCost":true}}"#).unwrap();
@@ -1361,6 +1552,22 @@ mod tests {
         assert_eq!(restored.agents, settings.agents);
     }
 
+    #[test]
+    fn hand_edited_agent_values_it_does_not_know_keep_the_rest() {
+        let settings: Settings = serde_json::from_str(
+            r#"{"editor":{"fontSize":17},"agents":{"thinking":"open","sendWith":"modEnter",
+                "defaults":{"claude":{"model":"opus","effort":3},"codex":"x"}}}"#,
+        )
+        .unwrap();
+        assert_eq!(settings.editor.font_size, 17.0);
+        assert_eq!(settings.agents.thinking, ThinkingDisplay::Auto);
+        assert_eq!(settings.agents.send_with, SendKey::ModEnter);
+        assert_eq!(
+            settings.agents.defaults,
+            BTreeMap::from([("claude".into(), BTreeMap::from([("model".into(), "opus".into())]))])
+        );
+    }
+
     #[test]
     fn main_menu_style_defaults_and_round_trips() {
         let old: Settings = serde_json::from_str(r#"{"appearance":{"compactMode":true}}"#).unwrap();

crates/ide-core/src/workflow_settings.rs

@@ -43,6 +43,7 @@ impl Default for VcsSettings {
 pub struct GitSettings {
     /// Show blame after the current editor line.
     pub inline_blame: bool,
+    pub show_branch_in_project_view: bool,
     /// Path to the git executable; empty = auto-detect.
     pub executable: String,
     /// Default of Update Project: `merge` | `rebase`.
@@ -74,6 +75,7 @@ impl Default for GitSettings {
     fn default() -> Self {
         Self {
             inline_blame: false,
+            show_branch_in_project_view: false,
             executable: String::new(),
             update_method: "merge".into(),
             auto_update_on_push_rejected: false,
@@ -115,6 +117,13 @@ pub struct CommitSettings {
     pub wrap_at_margin: bool,
     /// Plugin before-commit checks turned off (`<plugin id>/<check id>`); the rest run.
     pub disabled_plugin_checks: Vec<String>,
+    /// Double-click / Enter in the changes view: `None` follows the interface (the
+    /// Commit tool window opens the diff, Local Changes the source file).
+    ///
+    /// No `skip_serializing_if`: an unset value must still appear in
+    /// `Settings::default()`, or `SettingsStore::set` rejects the key as unknown.
+    #[specta(optional)]
+    pub double_click_opens_diff: Option<bool>,
 }
 
 impl Default for CommitSettings {
@@ -135,6 +144,7 @@ impl Default for CommitSettings {
             show_right_margin: true,
             wrap_at_margin: false,
             disabled_plugin_checks: Vec::new(),
+            double_click_opens_diff: None,
         }
     }
 }
@@ -312,6 +322,7 @@ pub struct TerminalSettings {
     pub override_ide_shortcuts: bool,
     pub shell_integration: bool,
     pub highlight_hyperlinks: bool,
+    pub highlight_selection: bool,
     pub option_as_meta: bool,
     /// Escape moves focus to the editor instead of reaching the shell.
     pub escape_to_editor: bool,
@@ -344,6 +355,7 @@ impl Default for TerminalSettings {
             override_ide_shortcuts: true,
             shell_integration: true,
             highlight_hyperlinks: true,
+            highlight_selection: true,
             option_as_meta: false,
             escape_to_editor: false,
             cursor_shape: "block".into(),

crates/ide-dap/Cargo.toml

@@ -11,12 +11,17 @@ tempfile.workspace = true
 ide-core.workspace = true
 ide-language.workspace = true
 ide-jsonrpc.workspace = true
+ide-jvm-attach.workspace = true
+ide-jvm-inspect.workspace = true
+ide-jdwp.workspace = true
+ide-heap.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 specta.workspace = true
 tokio = { workspace = true, features = ["net"] }
 parking_lot.workspace = true
 memchr = "2"
+percent-encoding = "2"
 portable-pty.workspace = true
 tracing.workspace = true
 
@@ -24,7 +29,5 @@ tracing.workspace = true
 libc = "0.2"
 
 [dev-dependencies]
-ide-remote.workspace = true
-ide-run.workspace = true
 tracing-subscriber.workspace = true
 tokio = { workspace = true, features = ["net", "rt-multi-thread", "macros", "test-util"] }

crates/ide-dap/src/adapter.rs

@@ -31,7 +31,6 @@ pub enum Transport {
 /// A fully resolved adapter command line.
 #[derive(Clone, Debug)]
 pub struct AdapterSpec {
-    pub target: Option<crate::target::TargetMapping>,
     pub adapter: String,
     pub command: String,
     pub args: Vec<String>,
@@ -52,7 +51,6 @@ pub struct AdapterSpec {
 /// Built-in adapters used when no language definition names `adapter`.
 fn builtin(adapter: &str) -> Option<DebuggerConfig> {
     let cfg = |command: &str, args: &[&str], transport: &str, hint: &str| DebuggerConfig {
-        target_placement: None,
         adapter: adapter.to_owned(),
         command: command.to_owned(),
         args: args.iter().map(|a| (*a).to_owned()).collect(),
@@ -103,6 +101,14 @@ fn builtin(adapter: &str) -> Option<DebuggerConfig> {
         "lldb-dap" => {
             cfg("lldb-dap", &[], "stdio", "Install LLVM's lldb-dap (brew install llvm; on macOS `xcrun -f lldb-dap`)")
         }
+        // GDB's own DAP interpreter, stdio transport. The DAP support it needs shipped in GDB 14
+        // (`prepare_gdb` refuses older ones with the required version in the message).
+        "gdb" => cfg(
+            "gdb",
+            &["-i", "dap"],
+            "stdio",
+            "Install GDB 14 or newer (apt install gdb, dnf install gdb, brew install gdb)",
+        ),
         "rdbg" => cfg("rdbg", &["-O", "--port", PORT_PLACEHOLDER, "-c"], "tcp", "gem install debug"),
         // A jdtls bundle: the session is started through jdtls and reached via `debugServer`.
         "java-debug" => cfg(
@@ -129,6 +135,7 @@ pub fn default_type(adapter: &str) -> Option<&'static str> {
         "delve" => "go",
         "netcoredbg" => "coreclr",
         "lldb-dap" => "lldb-dap",
+        "gdb" => "gdb",
         "java-debug" => "java",
         _ => return None,
     })
@@ -136,7 +143,6 @@ pub fn default_type(adapter: &str) -> Option<&'static str> {
 
 pub fn resolve(config: &DebuggerConfig, cwd: PathBuf) -> AdapterSpec {
     AdapterSpec {
-        target: None,
         adapter: config.adapter.clone(),
         command: config.command.clone(),
         args: config.args.clone(),
@@ -335,6 +341,89 @@ pub async fn prepare_debugpy(spec: &mut AdapterSpec) -> IdeResult<()> {
     )))
 }
 
+/// GDB's DAP interpreter (`-i dap`) shipped in GDB 14; older ones exit with
+/// "Interpreter `dap' unrecognized".
+const GDB_MIN_MAJOR: u32 = 14;
+
+/// `(major, minor)` of the first version number in the output of `gdb --version`
+/// (`GNU gdb (GDB) 14.2`, `GNU gdb (Ubuntu 12.1-0ubuntu1~22.04.2) 12.1`, `GNU gdb
+/// (GDB) 15.0.50.20240403-0ubuntu1`). `None` when no standalone version number is there.
+pub fn parse_gdb_version(output: &str) -> Option<(u32, u32)> {
+    let line = output.lines().next()?;
+    // Distribution names can contain versions, e.g. `(GDB; SUSE Linux Enterprise 15) 14.2`.
+    let line = line.rsplit_once(')').map_or(line, |(_, version)| version);
+    let b = line.as_bytes();
+    let mut i = 0;
+    while i < b.len() {
+        if !b[i].is_ascii_digit() {
+            i += 1;
+            continue;
+        }
+        let start = i;
+        while i < b.len() && b[i].is_ascii_digit() {
+            i += 1;
+        }
+        let major: u32 = line[start..i].parse().ok()?;
+        let mut minor = 0;
+        if i + 1 < b.len() && b[i] == b'.' && b[i + 1].is_ascii_digit() {
+            i += 1;
+            let ms = i;
+            while i < b.len() && b[i].is_ascii_digit() {
+                i += 1;
+            }
+            minor = line[ms..i].parse().unwrap_or(0);
+        }
+        // A version stands alone: `mingw32-gdb13.exe`'s embedded digits are part of a word.
+        if start > 0 && (b[start - 1].is_ascii_alphabetic() || b[start - 1] == b'_') {
+            continue;
+        }
+        return Some((major, minor));
+    }
+    None
+}
+
+/// Probe the already resolved and verified executable with its launch environment.
+async fn gdb_version(binary: &Path, spec: &AdapterSpec) -> IdeResult<Option<(u32, u32)>> {
+    let mut probe = Command::new(binary);
+    if let Some(path) = adapter_path(&spec.env) {
+        probe.env("PATH", path);
+    }
+    ide_core::process::prepare(probe.as_std_mut());
+    let probe = probe
+        .arg("--version")
+        .current_dir(&spec.cwd)
+        .envs(spec.env.iter().cloned())
+        .stdin(Stdio::null())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::null())
+        .kill_on_drop(true)
+        .output();
+    let Ok(Ok(out)) = tokio::time::timeout(Duration::from_secs(15), probe).await else {
+        return Ok(None);
+    };
+    Ok(parse_gdb_version(&String::from_utf8_lossy(&out.stdout)))
+}
+
+/// Refuse old GDB versions and report whether launch must follow configurationDone.
+/// GDB 15 starts the inferior in launch; 14 and 16+ start it at configurationDone.
+async fn prepare_gdb(spec: &AdapterSpec, binary: &Path) -> IdeResult<bool> {
+    let Some((major, minor)) = gdb_version(binary, spec).await? else {
+        return Ok(false);
+    };
+    if major >= GDB_MIN_MAJOR {
+        return Ok(major == 15);
+    }
+    let mut msg = format!(
+        "debugging with GDB needs GDB {GDB_MIN_MAJOR} or newer (found {major}.{minor}): \
+         this one has no DAP interpreter (`gdb -i dap`)"
+    );
+    if let Some(hint) = &spec.install_hint {
+        msg.push_str(". ");
+        msg.push_str(hint);
+    }
+    Err(IdeError::unavailable(msg))
+}
+
 /// An adapter that is a plugin of another program (java-debug, a jdtls bundle) rather
 /// than a program: it has no process of its own and is reached through `debugServer`.
 pub fn is_plugin_bundle(command: &str) -> bool {
@@ -368,6 +457,8 @@ pub type BoxWriter = Box<dyn AsyncWrite + Unpin + Send>;
 
 /// A connected adapter: byte streams plus the process (if we spawned one).
 pub struct AdapterIo {
+    /// GDB 15 starts running inside `launch`; configure breakpoints before sending it.
+    pub launch_after_configuration: bool,
     pub reader: BoxReader,
     pub writer: BoxWriter,
     pub child: Option<Child>,
@@ -419,6 +510,7 @@ impl AdapterLauncher for ProcessLauncher {
                 let stream = connect_with_retries(host, port, None, timeout).await?;
                 let (r, w) = stream.into_split();
                 return Ok(AdapterIo {
+                    launch_after_configuration: false,
                     reader: Box::new(r),
                     writer: Box::new(w),
                     child: None,
@@ -442,6 +534,7 @@ impl AdapterLauncher for ProcessLauncher {
                 let _ = stream.set_nodelay(true);
                 let (r, w) = stream.into_split();
                 return Ok(AdapterIo {
+                    launch_after_configuration: false,
                     reader: Box::new(r),
                     writer: Box::new(w),
                     child: None,
@@ -450,7 +543,7 @@ impl AdapterLauncher for ProcessLauncher {
                     program_output: None,
                 });
             }
-            if spec.adapter == DEBUGPY_TOOL && spec.target.is_none() {
+            if spec.adapter == DEBUGPY_TOOL {
                 prepare_debugpy(&mut spec).await?;
             }
             if is_plugin_bundle(&spec.command) {
@@ -470,9 +563,15 @@ impl AdapterLauncher for ProcessLauncher {
                         .ok_or_else(|| missing(&spec))?
                 }
             };
+            let launch_after_configuration =
+                if spec.adapter == "gdb" { prepare_gdb(&spec, &binary).await? } else { false };
             let base_args = substitute_root(&spec.args, &spec.cwd);
             match spec.transport {
-                Transport::Stdio => spawn_adapter(&spec, &binary, &base_args, None, CONNECT_TIMEOUT).await,
+                Transport::Stdio => {
+                    let mut io = spawn_adapter(&spec, &binary, &base_args, None, CONNECT_TIMEOUT).await?;
+                    io.launch_after_configuration = launch_after_configuration;
+                    Ok(io)
+                }
                 Transport::Tcp => {
                     // An embedded adapter started without `${port}` listens on its usual
                     // address; every other TCP adapter gets a port chosen here so it can be
@@ -489,7 +588,10 @@ impl AdapterLauncher for ProcessLauncher {
                         };
                         let args = substitute_port(&base_args, port);
                         match spawn_adapter(&spec, &binary, &args, Some(port), start_timeout).await {
-                            Ok(io) => return Ok(io),
+                            Ok(mut io) => {
+                                io.launch_after_configuration = launch_after_configuration;
+                                return Ok(io);
+                            }
                             Err(e) => {
                                 if fixed.is_none() && attempt < PORT_ATTEMPTS && is_port_race(&e) {
                                     tracing::warn!(
@@ -552,6 +654,7 @@ async fn spawn_adapter(
             let stdin = child.stdin.take().ok_or_else(|| IdeError::internal("adapter stdin unavailable"))?;
             let stdout = child.stdout.take().ok_or_else(|| IdeError::internal("adapter stdout unavailable"))?;
             Ok(AdapterIo {
+                launch_after_configuration: false,
                 reader: Box::new(stdout),
                 writer: Box::new(stdin),
                 child: Some(child),
@@ -583,6 +686,7 @@ async fn spawn_adapter(
             };
             let (r, w) = stream.into_split();
             Ok(AdapterIo {
+                launch_after_configuration: false,
                 reader: Box::new(r),
                 writer: Box::new(w),
                 child: Some(child),
@@ -740,15 +844,102 @@ mod tests {
 
     #[test]
     fn builtins_cover_common_adapters() {
-        for name in ["codelldb", "debugpy", "js-debug", "delve", "netcoredbg", "java-debug"] {
+        for name in ["codelldb", "debugpy", "js-debug", "delve", "netcoredbg", "java-debug", "gdb"] {
             let cfg = builtin(name).unwrap();
             assert!(cfg.install_hint.is_some());
         }
         let delve = resolve(&builtin("delve").unwrap(), PathBuf::from("/"));
         assert_eq!(delve.transport, Transport::Tcp);
+        // GDB's own DAP interpreter over stdio, with the required version in its hint.
+        let gdb = builtin("gdb").unwrap();
+        assert_eq!(gdb.command, "gdb");
+        assert_eq!(gdb.args, ["-i", "dap"]);
+        assert_eq!(gdb.transport, "stdio");
+        assert!(gdb.install_hint.as_deref().is_some_and(|h| h.contains("14")), "{gdb:?}");
+        assert_eq!(default_type("gdb"), Some("gdb"));
         assert!(builtin("nope").is_none());
     }
 
+    /// The first version number of `gdb --version`'s first line, however the distro decorates it.
+    #[test]
+    fn parses_gdb_versions() {
+        for (out, want) in [
+            ("GNU gdb (GDB) 14.2\nCopyright (C) 2023 Free Software Foundation", Some((14, 2))),
+            ("GNU gdb (GDB) 15.0.50.20240403-0ubuntu1\n", Some((15, 0))),
+            ("GNU gdb (Ubuntu 12.1-0ubuntu1~22.04.2) 12.1", Some((12, 1))),
+            ("GNU gdb (Debian 13.1-3) 13.1", Some((13, 1))),
+            ("GNU gdb (GDB) Fedora Linux 16.3-1.fc41", Some((16, 3))),
+            ("GNU gdb (GDB; SUSE Linux Enterprise 15) 14.2", Some((14, 2))),
+            ("GNU gdb (GDB; SUSE Linux Enterprise 15) 11.1", Some((11, 1))),
+            ("mingw32-gdb13.exe (GDB) 13.2", Some((13, 2))),
+            ("GNU gdb 14", Some((14, 0))),
+            ("no version here", None),
+            ("", None),
+        ] {
+            assert_eq!(parse_gdb_version(out), want, "{out}");
+        }
+    }
+
+    #[tokio::test]
+    async fn gdb_probe_never_executes_a_changed_pinned_program() {
+        let dir = tempfile::tempdir().unwrap();
+        let fake = dir.path().join(if cfg!(windows) { "gdb.cmd" } else { "gdb" });
+        std::fs::write(&fake, "approved").unwrap();
+        let pin = ProgramPin::approve(&fake).unwrap();
+        #[cfg(windows)]
+        std::fs::write(&fake, "@echo off\r\necho ran>probe-ran\r\necho GNU gdb (GDB) 15.1\r\n").unwrap();
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            std::fs::write(&fake, "#!/bin/sh\ntouch probe-ran\necho 'GNU gdb (GDB) 15.1'\n").unwrap();
+            std::fs::set_permissions(&fake, std::fs::Permissions::from_mode(0o755)).unwrap();
+        }
+        let mut spec = resolve(&builtin("gdb").unwrap(), dir.path().to_owned());
+        spec.command = fake.to_string_lossy().into_owned();
+        spec.pinned = Some(pin);
+        let error = ProcessLauncher.launch(spec, None).await.err().expect("changed program is refused");
+        assert_eq!(error.kind, ide_core::error::ErrorKind::PermissionDenied);
+        assert!(!dir.path().join("probe-ran").exists(), "the version probe executed an unapproved program");
+    }
+
+    #[tokio::test]
+    async fn gdb_probe_uses_the_verified_program_and_launch_environment_once() {
+        use tokio::io::AsyncReadExt;
+        let dir = tempfile::tempdir().unwrap();
+        let fake = dir.path().join(if cfg!(windows) { "gdb.cmd" } else { "gdb" });
+        #[cfg(windows)]
+        std::fs::write(&fake, "@echo off\r\nif \"%~1\"==\"--version\" (\r\n echo probe>>probes\r\n echo GNU gdb ^(GDB^) %GDB_TEST_VERSION%\r\n) else (\r\n echo adapter\r\n)\r\n").unwrap();
+        #[cfg(unix)]
+        {
+            use std::os::unix::fs::PermissionsExt;
+            std::fs::write(&fake, "#!/bin/sh\nif [ \"$1\" = --version ]; then\n echo probe >> probes\n echo \"GNU gdb (GDB) $GDB_TEST_VERSION\"\nelse\n echo adapter\nfi\n").unwrap();
+            std::fs::set_permissions(&fake, std::fs::Permissions::from_mode(0o755)).unwrap();
+        }
+        let pin = ProgramPin::approve(&fake).unwrap();
+        for (version, deferred) in [("12.1", false), ("14.2", false), ("15.1", true), ("16.3", false)] {
+            let mut spec = resolve(&builtin("gdb").unwrap(), dir.path().to_owned());
+            // Only the approved path is executable; the symbolic command must never be probed.
+            spec.command = "definitely-not-a-real-binary-openidea".into();
+            spec.pinned = Some(pin.clone());
+            spec.env.push(("GDB_TEST_VERSION".into(), version.into()));
+            let result = ProcessLauncher.launch(spec, None).await;
+            if version == "12.1" {
+                let error = result.err().expect("GDB 12 has no DAP interpreter");
+                assert_eq!(error.kind, ide_core::error::ErrorKind::Unavailable);
+                assert!(error.message.contains("GDB 14 or newer"), "{}", error.message);
+                assert!(error.message.contains("12.1"), "{}", error.message);
+            } else {
+                let mut io = result.unwrap();
+                assert_eq!(io.launch_after_configuration, deferred, "{version}");
+                let mut output = String::new();
+                io.reader.read_to_string(&mut output).await.unwrap();
+                assert_eq!(output.trim(), "adapter");
+                io.child.as_mut().unwrap().wait().await.unwrap();
+            }
+        }
+        assert_eq!(std::fs::read_to_string(dir.path().join("probes")).unwrap().lines().count(), 4);
+    }
+
     #[test]
     fn free_port_is_nonzero() {
         assert_ne!(free_port().unwrap(), 0);

crates/ide-dap/src/connection.rs

@@ -71,7 +71,6 @@ pub enum Incoming {
 type Pending = HashMap<i64, (String, oneshot::Sender<Result<Value, DapError>>)>;
 
 struct Inner {
-    mapping: Option<crate::target::TargetMapping>,
     out: mpsc::UnboundedSender<Vec<u8>>,
     pending: Mutex<Pending>,
     seq: AtomicI64,
@@ -107,22 +106,9 @@ impl Connection {
     /// [`start`](Self::start) that hands lines outside the protocol (an adapter's
     /// own output on stdout, decoded) to `on_output`.
     pub fn start_with_output<R, W>(
-        reader: R,
-        writer: W,
-        on_output: Box<dyn Fn(String) + Send + Sync>,
-    ) -> (Self, mpsc::UnboundedReceiver<Incoming>)
-    where
-        R: AsyncRead + Unpin + Send + 'static,
-        W: AsyncWrite + Unpin + Send + 'static,
-    {
-        Self::start_with_target(reader, writer, on_output, None)
-    }
-
-    pub fn start_with_target<R, W>(
         reader: R,
         mut writer: W,
         on_output: Box<dyn Fn(String) + Send + Sync>,
-        target: Option<crate::target::TargetMapping>,
     ) -> (Self, mpsc::UnboundedReceiver<Incoming>)
     where
         R: AsyncRead + Unpin + Send + 'static,
@@ -131,7 +117,6 @@ impl Connection {
         let (out_tx, mut out_rx) = mpsc::unbounded_channel::<Vec<u8>>();
         let (in_tx, in_rx) = mpsc::unbounded_channel();
         let inner = Arc::new(Inner {
-            mapping: target,
             out: out_tx,
             pending: Mutex::new(HashMap::new()),
             seq: AtomicI64::new(1),
@@ -202,11 +187,7 @@ impl Connection {
         if self.is_closed() {
             return Err(DapError::Closed);
         }
-        let mut value = value.clone();
-        if let Some(mapping) = self.inner.mapping.as_ref() {
-            mapping.rewrite(&mut value, ide_core::path_mapping::Direction::ToTarget);
-        }
-        let body = serde_json::to_vec(&value).map_err(|e| DapError::Protocol(e.to_string()))?;
+        let body = serde_json::to_vec(value).map_err(|e| DapError::Protocol(e.to_string()))?;
         tracing::trace!(target: "ide_dap::wire", "--> {}", String::from_utf8_lossy(&body));
         self.inner.out.send(body).map_err(|_| DapError::Closed)
     }
@@ -265,16 +246,7 @@ impl Connection {
 
 fn dispatch(inner: &Inner, incoming: &mpsc::UnboundedSender<Incoming>, body: &[u8]) {
     tracing::trace!(target: "ide_dap::wire", "<-- {}", String::from_utf8_lossy(body));
-    let mut msg: Value = match serde_json::from_slice(body) {
-        Ok(v) => v,
-        Err(e) => {
-            tracing::warn!("dap: unparsable message: {e}");
-            return;
-        }
-    };
-    if let Some(mapping) = inner.mapping.as_ref() {
-        mapping.rewrite(&mut msg, ide_core::path_mapping::Direction::ToHost);
-    }
+    let Some(msg) = parse_message(body) else { return };
     match msg.get("type").and_then(Value::as_str) {
         Some("response") => {
             let Some(request_seq) = msg.get("request_seq").and_then(Value::as_i64) else {
@@ -307,6 +279,25 @@ fn dispatch(inner: &Inner, incoming: &mpsc::UnboundedSender<Incoming>, body: &[u
     }
 }
 
+/// A message body as JSON. Some adapters pass the debuggee's output through as it was
+/// written: netcoredbg on Windows embeds console output in the ANSI code page (GBK on a
+/// Chinese system), which isn't valid UTF-8 and made the whole `output` event unparsable,
+/// so every line with non-ASCII text went missing. Such a body is decoded like other tool
+/// output (UTF-8, else the system code page) before parsing.
+fn parse_message(body: &[u8]) -> Option<Value> {
+    let error = match serde_json::from_slice(body) {
+        Ok(v) => return Some(v),
+        Err(e) => e,
+    };
+    if std::str::from_utf8(body).is_err()
+        && let Ok(v) = serde_json::from_str(&ide_core::output_encoding::decode_tool_output(body))
+    {
+        return Some(v);
+    }
+    tracing::warn!("dap: unparsable message: {error}");
+    None
+}
+
 /// `message`, or the formatted `body.error` (`{format, variables}`) when present.
 fn error_message(msg: &Value) -> String {
     if let Some(err) = msg.pointer("/body/error")
@@ -328,6 +319,22 @@ fn error_message(msg: &Value) -> String {
 mod tests {
     use super::*;
 
+    #[test]
+    fn parses_output_events_with_non_utf8_text() {
+        // "中文" in GBK inside an output event, as netcoredbg sends it on a Chinese Windows.
+        let mut body = br#"{"seq":5,"type":"event","event":"output","body":{"category":"stdout","output":""#.to_vec();
+        body.extend_from_slice(&[0xd6, 0xd0, 0xce, 0xc4]);
+        body.extend_from_slice(br#"\n"}}"#);
+        let msg = parse_message(&body).expect("parsed");
+        assert_eq!(msg["event"], "output");
+        let output = msg["body"]["output"].as_str().unwrap();
+        assert!(output.ends_with('\n'));
+        // Off Windows (UTF-8 code page) the bytes decode lossily; the line still arrives.
+        #[cfg(not(windows))]
+        assert!(output.starts_with(char::REPLACEMENT_CHARACTER));
+        assert!(parse_message(b"{not json").is_none());
+    }
+
     #[test]
     fn formats_structured_errors() {
         let msg =
@@ -335,4 +342,16 @@ mod tests {
         assert_eq!(error_message(&msg), "cannot find a.py");
         assert_eq!(error_message(&json!({"message": "nope"})), "nope");
     }
+
+    #[test]
+    fn a_failed_launch_response_keeps_delves_too_old_error_verbatim() {
+        // The UI's repair offer keys off this exact wording (`missingAdapter`), so the
+        // conversion to the IPC error must not fold it into a generic message.
+        let message = "Failed to launch /p/api: Version of Delve is too old for Go version go1.27.0 \
+                       (maximum supported version 1.26, suppress this error with --check-go-version=false)";
+        let e = ide_core::IdeError::from(DapError::Failed { command: "launch".into(), message: message.into() });
+        assert_eq!(e.kind, ide_core::error::ErrorKind::InvalidInput);
+        assert_eq!(e.message, format!("launch failed: {message}"));
+        assert!(e.message.contains("Version of Delve is too old for Go version go1.27.0"));
+    }
 }

crates/ide-dap/src/jdwp.rs

@@ -12,6 +12,35 @@ use tokio::net::{TcpListener, TcpStream};
 /// How long the relay waits for java-debug to attach once the JVM is connected.
 const ATTACH_TIMEOUT: Duration = Duration::from_secs(60);
 
+/// Loopback ports relaying a connected JVM, while their relay runs.
+static RELAY_PORTS: std::sync::Mutex<Vec<u16>> = std::sync::Mutex::new(Vec::new());
+
+fn relay_ports() -> std::sync::MutexGuard<'static, Vec<u16>> {
+    RELAY_PORTS.lock().unwrap_or_else(std::sync::PoisonError::into_inner)
+}
+
+/// Whether `port` is a relay of [`listen_for_jvm`]: a session attaching to it debugs a JVM that
+/// connected to the IDE, so the JVM has no JDWP listener the memory view could find it by.
+pub(crate) fn is_listen_relay(port: u16) -> bool {
+    relay_ports().contains(&port)
+}
+
+/// Registers a relay port for as long as it lives.
+struct RelayPort(u16);
+
+impl RelayPort {
+    fn new(port: u16) -> Self {
+        relay_ports().push(port);
+        Self(port)
+    }
+}
+
+impl Drop for RelayPort {
+    fn drop(&mut self) {
+        relay_ports().retain(|&p| p != self.0);
+    }
+}
+
 /// The address to listen on for `host`: the interface it names, or every interface when
 /// it is not one of this machine's (a DNS name or a NAT address the JVM connects to).
 async fn bind(host: &str, port: u16) -> IdeResult<TcpListener> {
@@ -40,11 +69,11 @@ pub async fn listen_for_jvm(host: &str, port: u16, cancel: CancellationToken) ->
     let _ = jvm.set_nodelay(true);
     let relay = TcpListener::bind(("127.0.0.1", 0)).await?;
     let local = relay.local_addr()?.port();
-    tokio::spawn(relay_one(relay, jvm));
+    tokio::spawn(relay_one(relay, jvm, RelayPort::new(local)));
     Ok(local)
 }
 
-async fn relay_one(relay: TcpListener, mut jvm: TcpStream) {
+async fn relay_one(relay: TcpListener, mut jvm: TcpStream, _registered: RelayPort) {
     let debugger = match tokio::time::timeout(ATTACH_TIMEOUT, relay.accept()).await {
         Ok(Ok((s, _))) => s,
         _ => return,
@@ -58,22 +87,64 @@ async fn relay_one(relay: TcpListener, mut jvm: TcpStream) {
 }
 
 #[cfg(test)]
-mod tests {
+pub(crate) mod tests {
     use super::*;
     use tokio::io::{AsyncReadExt, AsyncWriteExt};
 
-    #[tokio::test]
-    async fn relays_the_jdwp_handshake_both_ways() {
-        let port = TcpListener::bind(("127.0.0.1", 0)).await.unwrap().local_addr().unwrap().port();
-        let waiting = tokio::spawn(listen_for_jvm("127.0.0.1", port, CancellationToken::new()));
-        // The remote JVM (`server=n`) connects to the IDE.
-        let mut jvm = loop {
-            if let Ok(s) = TcpStream::connect(("127.0.0.1", port)).await {
-                break s;
+    /// A remote JVM (`server=n`) connected to [`listen_for_jvm`], and the relay port. A port
+    /// picked by binding to 0 can be taken by a parallel test before `listen_for_jvm` binds it,
+    /// so a failed listen is retried on a fresh one.
+    pub(crate) async fn connected_jvm() -> (TcpStream, u16) {
+        for _ in 0..20 {
+            let port = TcpListener::bind(("127.0.0.1", 0)).await.unwrap().local_addr().unwrap().port();
+            if let Some(connected) = jvm_on(port).await {
+                return connected;
+            }
+        }
+        panic!("listen_for_jvm never accepted a JVM");
+    }
+
+    /// One attempt of [`connected_jvm`]; `None` when the port turned out to be taken.
+    async fn jvm_on(port: u16) -> Option<(TcpStream, u16)> {
+        let mut waiting = tokio::spawn(listen_for_jvm("127.0.0.1", port, CancellationToken::new()));
+        let mut jvm = None;
+        for _ in 0..100 {
+            // A listen that failed to bind leaves nothing to connect to.
+            if waiting.is_finished() {
+                break;
+            }
+            // macOS does not refuse a connect to a port a socket holds without listening: the
+            // SYN goes unanswered until the connect times out.
+            let connect = TcpStream::connect(("127.0.0.1", port));
+            if let Ok(Ok(s)) = tokio::time::timeout(Duration::from_secs(1), connect).await {
+                jvm = Some(s);
+                break;
             }
             tokio::time::sleep(Duration::from_millis(20)).await;
-        };
-        let local = waiting.await.unwrap().unwrap();
+        }
+        // A connection to another test's listener never reaches `listen_for_jvm`.
+        let relay = tokio::time::timeout(Duration::from_secs(2), &mut waiting).await;
+        if let (Some(jvm), Ok(Ok(Ok(relay)))) = (jvm, relay) {
+            return Some((jvm, relay));
+        }
+        waiting.abort();
+        None
+    }
+
+    #[tokio::test]
+    async fn a_port_another_socket_holds_is_given_up() {
+        // Bound but not listening, as a parallel test's outgoing connection holds its local port.
+        let held = tokio::net::TcpSocket::new_v4().unwrap();
+        held.bind(([127, 0, 0, 1], 0).into()).unwrap();
+        let port = held.local_addr().unwrap().port();
+        let attempt = tokio::time::timeout(Duration::from_secs(5), jvm_on(port)).await;
+        assert!(matches!(attempt, Ok(None)), "an attempt on a taken port gives up instead of waiting forever");
+    }
+
+    #[tokio::test]
+    async fn relays_the_jdwp_handshake_both_ways() {
+        // The remote JVM (`server=n`) connects to the IDE.
+        let (mut jvm, local) = connected_jvm().await;
         // java-debug attaches to the relay and starts the handshake.
         let mut debugger = TcpStream::connect(("127.0.0.1", local)).await.unwrap();
         debugger.write_all(b"JDWP-Handshake").await.unwrap();
@@ -85,6 +156,22 @@ mod tests {
         assert_eq!(&buf, b"JDWP-Handshake");
     }
 
+    #[tokio::test]
+    async fn relay_port_is_known_while_the_relay_runs() {
+        let (jvm, local) = connected_jvm().await;
+        assert!(is_listen_relay(local));
+
+        let debugger = TcpStream::connect(("127.0.0.1", local)).await.unwrap();
+        drop((jvm, debugger));
+        for _ in 0..200 {
+            if !is_listen_relay(local) {
+                return;
+            }
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+        panic!("relay port {local} still registered after the relay ended");
+    }
+
     #[tokio::test]
     async fn waiting_is_cancellable() {
         let cancel = CancellationToken::new();

crates/ide-dap/src/jvm_memory/fallback.rs

@@ -0,0 +1,92 @@
+//! The class table counted by the debugger (JDWP `InstanceCounts`) where no histogram can be
+//! taken: JDK 8-16 while suspended, Windows, a remote JVM. Only while suspended, and slow on a
+//! large heap (seconds on JDK 17+).
+
+use super::inspect::Call;
+use super::snapshot::diff_rows;
+use super::{ClassCounts, JvmMemoryResult, JvmMemorySnapshot, JvmMemorySource, JvmMemoryState, JvmMemoryUnavailable};
+use crate::session::Session;
+use ide_core::IdeResult;
+use ide_jvm_attach::HistogramRow;
+use ide_jvm_inspect::ClassCount;
+
+/// Reasons the debugger may be able to work around; the others (the program exited, the JVM
+/// did not answer) would fail for it too.
+pub(super) fn falls_back(reason: &JvmMemoryUnavailable) -> bool {
+    use JvmMemoryUnavailable as U;
+    matches!(
+        reason,
+        U::UnsafeWhileSuspended { .. }
+            | U::UnsupportedPlatform
+            | U::AttachedJvmNotFound
+            | U::ListenerNotRunning
+            | U::ListenModeNotSupported
+            | U::NoJvmProcess
+    )
+}
+
+/// `histogram` unless it is unavailable for a reason `session`'s inspector can work around.
+pub(super) async fn or_debugger_counts(
+    state: &mut JvmMemoryState,
+    histogram: Result<JvmMemorySnapshot, JvmMemoryUnavailable>,
+    session: Option<&Session>,
+) -> IdeResult<JvmMemoryResult> {
+    let reason = match histogram {
+        Ok(snapshot) => return Ok(JvmMemoryResult::Ready { snapshot }),
+        Err(reason) => reason,
+    };
+    let unavailable = |can_count_when_paused| Ok(JvmMemoryResult::Unavailable { reason, can_count_when_paused });
+    let Some(session) = session.filter(|_| falls_back(&reason)) else {
+        return unavailable(false);
+    };
+    let call = match Call::begin(session, None).await {
+        Ok(call) => call,
+        Err(super::JvmInspectUnavailable::NotSuspended) => return unavailable(true),
+        Err(_) => return unavailable(false),
+    };
+    let started = std::time::Instant::now();
+    let result = call.run(call.inspector.class_counts(&call.target)).await;
+    match call.finish(result) {
+        Ok(counts) => {
+            let elapsed_ms = u32::try_from(started.elapsed().as_millis()).unwrap_or(u32::MAX);
+            let previous = state.baseline(JvmMemorySource::Debugger);
+            let (snapshot, counts) = debugger_snapshot(counts, previous.as_deref(), elapsed_ms);
+            state.remember(JvmMemorySource::Debugger, counts);
+            Ok(JvmMemoryResult::Ready { snapshot })
+        }
+        Err(e) => {
+            tracing::debug!("debugger class counts: {e}");
+            let running = !session.suspended.get();
+            unavailable(running && session.jvm_inspector.lock().is_some())
+        }
+    }
+}
+
+/// Classes without instances are left out; most instances first.
+pub(super) fn debugger_snapshot(
+    counts: Vec<ClassCount>,
+    previous: Option<&ClassCounts>,
+    elapsed_ms: u32,
+) -> (JvmMemorySnapshot, ClassCounts) {
+    let rows = counts
+        .into_iter()
+        .filter(|c| c.instances > 0)
+        .map(|c| HistogramRow { name: c.name, module: None, instances: c.instances, bytes: 0 })
+        .collect();
+    let (mut rows, counts) = diff_rows(rows, previous);
+    for row in &mut rows {
+        row.delta_bytes = None;
+    }
+    rows.sort_by(|a, b| b.instances.cmp(&a.instances).then_with(|| a.name.cmp(&b.name)));
+    let snapshot = JvmMemorySnapshot {
+        total_instances: rows.iter().map(|r| r.instances).sum(),
+        total_bytes: 0,
+        rows,
+        java_version: String::new(),
+        taken_while_suspended: true,
+        has_baseline: previous.is_some(),
+        elapsed_ms,
+        source: JvmMemorySource::Debugger,
+    };
+    (snapshot, counts)
+}

crates/ide-dap/src/jvm_memory/heap.rs

@@ -0,0 +1,293 @@
+//! A heap dump of a debugged JVM, written over its attach listener into a snapshot directory.
+
+use super::snapshot::{AttachProbe, JdkProbe, attach_failure, gone, pick_jvm_pid};
+use super::{
+    JvmMemoryState, JvmMemoryUnavailable, JvmTarget, histogram_pid, keep_found, lookup, resolve_jvm,
+    safe_while_suspended, session_target,
+};
+use crate::session::Session;
+use ide_core::{CancellationToken, IdeError, IdeResult};
+use ide_jvm_attach::{AttachError, HeapDumpReply};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::future::Future;
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+
+const DUMP_FILE: &str = "dump.hprof";
+/// For a refusal whose reply holds no reason: empty, or only the line announcing the dump.
+const NO_REASON: &str = "the JVM wrote no heap dump and gave no reason";
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(tag = "kind", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmHeapUnavailable {
+    /// The reason a class table could not be read applies to the dump too.
+    Memory {
+        reason: JvmMemoryUnavailable,
+    },
+    /// Bytes.
+    NotEnoughDiskSpace {
+        needed: u64,
+        available: u64,
+    },
+    DumpFailed {
+        message: String,
+    },
+    DumpTimedOut {
+        seconds: u32,
+    },
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub struct JvmHeapDump {
+    pub path: PathBuf,
+    /// The class histogram taken just before the dump.
+    pub histogram: Vec<ide_heap::HistogramEntry>,
+    /// Raw `VM.flags`; empty when the JVM did not answer.
+    pub vm_flags: String,
+    /// 0 when unknown.
+    pub java_major: u32,
+    /// Empty when unknown.
+    pub java_version: String,
+    pub pid: u32,
+    pub taken_while_suspended: bool,
+    pub dump_ms: u32,
+}
+
+#[derive(Clone, Debug, PartialEq)]
+pub enum JvmHeapOutcome {
+    Ready(JvmHeapDump),
+    /// The snapshot directory has been deleted.
+    Unavailable(JvmHeapUnavailable),
+    /// The snapshot directory has been deleted.
+    Cancelled,
+}
+
+pub(crate) async fn session_heap_dump(
+    session: Arc<Session>,
+    dir: PathBuf,
+    cancel: CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    let launched = histogram_pid(&session);
+    let capture = {
+        let (dir, cancel) = (dir.clone(), cancel.clone());
+        async move {
+            let target = session_target(&session, launched);
+            let probe = |suspended| -> Arc<dyn AttachProbe> { Arc::new(JdkProbe { suspended }) };
+            let stopped = session.clone();
+            let suspended = move || capture_suspended(&stopped);
+            heap_dump_with(&session.jvm_memory, suspended, probe, target, dir, cancel).await
+        }
+    };
+    detached(capture, dir, cancel).await
+}
+
+/// The JVM can be suspended before the adapter reports the stop, so a session with a JDWP link
+/// also counts the link's view.
+pub(super) fn capture_suspended(session: &Session) -> bool {
+    session.suspended.get()
+        || session
+            .jdwp_link
+            .lock()
+            .as_ref()
+            .is_some_and(|link| matches!(link.state(), ide_jdwp::LinkState::Suspended { .. }))
+}
+
+/// Runs `capture` in a task of its own, so a caller that stops waiting cannot release the
+/// session's lock while the JVM is still writing the dump and let a class-table request run
+/// next to it. On `cancel` returns at once and deletes `dir`.
+pub(super) async fn detached(
+    capture: impl Future<Output = IdeResult<JvmHeapOutcome>> + Send + 'static,
+    dir: PathBuf,
+    cancel: CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    let task = tokio::spawn(capture);
+    tokio::select! {
+        joined = task => joined.map_err(|e| IdeError::internal(format!("JVM heap dump failed: {e}")))?,
+        () = cancel.cancelled() => {
+            discard_later(dir).await;
+            Ok(JvmHeapOutcome::Cancelled)
+        }
+    }
+}
+
+/// Holds `state`'s lock throughout, as a class-table request does; `suspended` and then `probe`
+/// are read once it is held, and `suspended` again by [`take_heap_dump`]. Anything but `Ready`
+/// deletes `dir`.
+pub(super) async fn heap_dump_with(
+    state: &tokio::sync::Mutex<JvmMemoryState>,
+    suspended: impl Fn() -> bool + Send + Sync + 'static,
+    probe: impl FnOnce(bool) -> Arc<dyn AttachProbe>,
+    target: JvmTarget<'_>,
+    dir: PathBuf,
+    cancel: CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    // The capture's histogram never becomes the Memory view's baseline, so the state is unused.
+    let _turn = state.lock().await;
+    let outcome = capture(suspended, probe, target, dir.clone(), cancel).await;
+    if !matches!(outcome, Ok(JvmHeapOutcome::Ready(_))) {
+        discard_later(dir).await;
+    }
+    outcome
+}
+
+async fn capture(
+    suspended_now: impl Fn() -> bool + Send + Sync + 'static,
+    probe: impl FnOnce(bool) -> Arc<dyn AttachProbe>,
+    target: JvmTarget<'_>,
+    dir: PathBuf,
+    cancel: CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    if cancel.is_cancelled() {
+        return Ok(JvmHeapOutcome::Cancelled);
+    }
+    let suspended = suspended_now();
+    let lookup = match lookup(target) {
+        Ok(lookup) => lookup,
+        Err(reason) => return Ok(memory(reason)),
+    };
+    let probe = probe(suspended);
+    let (found, outcome) = tokio::task::spawn_blocking(move || match resolve_jvm(lookup, &*probe, suspended) {
+        Ok((tree, found)) => (found, take_heap_dump(&*probe, &tree, suspended, &suspended_now, &dir, &cancel)),
+        Err(reason) => (None, Ok(memory(reason))),
+    })
+    .await
+    .map_err(|e| IdeError::internal(format!("JVM heap dump failed: {e}")))?;
+    keep_found(target, found);
+    outcome
+}
+
+/// `tree` starts with the session's reported pid, followed by its descendants. `suspended` is
+/// the stop read when the capture began; `suspended_now` reads it again. Anything but `Ready`
+/// deletes `dir`.
+pub(crate) fn take_heap_dump(
+    probe: &dyn AttachProbe,
+    tree: &[i32],
+    suspended: bool,
+    suspended_now: &dyn Fn() -> bool,
+    dir: &Path,
+    cancel: &CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    let outcome = dump(probe, tree, suspended, suspended_now, dir, cancel);
+    if !matches!(outcome, Ok(JvmHeapOutcome::Ready(_))) {
+        discard(dir);
+    }
+    outcome
+}
+
+fn dump(
+    probe: &dyn AttachProbe,
+    tree: &[i32],
+    suspended: bool,
+    suspended_now: &dyn Fn() -> bool,
+    dir: &Path,
+    cancel: &CancellationToken,
+) -> IdeResult<JvmHeapOutcome> {
+    use JvmHeapUnavailable as H;
+    use JvmMemoryUnavailable as U;
+    let Some(root) = tree.first().and_then(|&p| u32::try_from(p).ok()) else {
+        return Ok(memory(U::NoJvmProcess));
+    };
+    let Some(jvm) = pick_jvm_pid(tree, |p| probe.has_listener(p)) else {
+        return Ok(memory(gone(probe, root)));
+    };
+
+    let version = probe.version(jvm);
+    let java_major = version.as_ref().map_or(0, |v| v.major);
+    let safe = safe_while_suspended(version.as_ref());
+    let unsafe_stop = || Ok(memory(U::UnsafeWhileSuspended { java_major }));
+    if suspended && !safe {
+        return unsafe_stop();
+    }
+    // The program may stop during the histogram, and a stopped JDK below 17 hangs on the next
+    // request until it resumes.
+    let stopped_since = || !safe && suspended_now();
+
+    let text = match probe.histogram(jvm) {
+        Ok(text) => text,
+        Err(e) => return attach_failure(probe, jvm, e, "class histogram").map(memory),
+    };
+    let histogram: Vec<ide_heap::HistogramEntry> = ide_jvm_attach::parse_class_histogram(&text)
+        .rows
+        .into_iter()
+        .map(|r| ide_heap::HistogramEntry { name: r.name, instances: r.instances, bytes: r.bytes })
+        .collect();
+    let (instances, bytes) =
+        histogram.iter().fold((0u64, 0u64), |(i, b), e| (i.saturating_add(e.instances), b.saturating_add(e.bytes)));
+    let needed = ide_heap::capture_need(bytes, instances);
+    if let Some(available) = probe.free_bytes(dir)
+        && available < needed
+    {
+        return Ok(JvmHeapOutcome::Unavailable(H::NotEnoughDiskSpace { needed, available }));
+    }
+
+    if stopped_since() {
+        return unsafe_stop();
+    }
+    // Without flags the index assumes the default object layout.
+    let vm_flags = probe.vm_flags(jvm).unwrap_or_else(|e| {
+        tracing::debug!("VM.flags of JVM {jvm}: {e}");
+        String::new()
+    });
+    if cancel.is_cancelled() {
+        return Ok(JvmHeapOutcome::Cancelled);
+    }
+    if stopped_since() {
+        return unsafe_stop();
+    }
+
+    let path = dir.join(DUMP_FILE);
+    let timeout = ide_jvm_attach::dump_timeout(bytes);
+    let started = std::time::Instant::now();
+    let reply = probe.heap_dump(jvm, &path, timeout);
+    let dump_ms = u32::try_from(started.elapsed().as_millis()).unwrap_or(u32::MAX);
+    if cancel.is_cancelled() {
+        return Ok(JvmHeapOutcome::Cancelled);
+    }
+    let failed = |message: String| Ok(JvmHeapOutcome::Unavailable(H::DumpFailed { message }));
+    match reply {
+        Ok(HeapDumpReply::Created { .. }) => {
+            if !std::fs::metadata(&path).is_ok_and(|m| m.is_file() && m.len() > 0) {
+                return failed(format!("the JVM reported a heap dump, but {} is missing or empty", path.display()));
+            }
+            Ok(JvmHeapOutcome::Ready(JvmHeapDump {
+                path,
+                histogram,
+                vm_flags,
+                java_major,
+                java_version: version.map(|v| v.text).unwrap_or_default(),
+                pid: jvm,
+                taken_while_suspended: suspended,
+                dump_ms,
+            }))
+        }
+        Ok(HeapDumpReply::Refused { message }) if message.is_empty() || message.starts_with("Dumping heap to") => {
+            failed(NO_REASON.into())
+        }
+        Ok(HeapDumpReply::Refused { message }) => failed(message),
+        Err(AttachError::Timeout) => {
+            let seconds = u32::try_from(timeout.as_secs()).unwrap_or(u32::MAX);
+            Ok(JvmHeapOutcome::Unavailable(H::DumpTimedOut { seconds }))
+        }
+        // A running JDK rejects an argument with a non-zero result code.
+        Err(AttachError::Command { message, .. }) => failed(message),
+        Err(e) => attach_failure(probe, jvm, e, "heap dump").map(memory),
+    }
+}
+
+fn memory(reason: JvmMemoryUnavailable) -> JvmHeapOutcome {
+    JvmHeapOutcome::Unavailable(JvmHeapUnavailable::Memory { reason })
+}
+
+fn discard(dir: &Path) {
+    if let Err(e) = std::fs::remove_dir_all(dir)
+        && e.kind() != std::io::ErrorKind::NotFound
+    {
+        tracing::warn!("could not delete heap snapshot directory {}: {e}", dir.display());
+    }
+}
+
+/// A dump may be large, so it is deleted off the async threads.
+async fn discard_later(dir: PathBuf) {
+    let _ = tokio::task::spawn_blocking(move || discard(&dir)).await;
+}

crates/ide-dap/src/jvm_memory/inspect.rs

@@ -0,0 +1,251 @@
+//! A suspended JVM's instances, fields and referrers, read through the session's
+//! [`JvmInspector`]. An object is only valid within the stop it was read in.
+
+use super::launch_pid;
+use crate::session::Session;
+use ide_core::event::{DebugEvent, JvmBackendState};
+use ide_core::{IdeError, IdeResult};
+use ide_jvm_inspect::{
+    DEFAULT_REFERRERS, InspectError, InspectFuture, JvmField, JvmInspector, JvmReferrer, JvmValue, MAX_INSTANCES,
+    MAX_REFERRERS, ObjectId, VmTarget,
+};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::sync::Arc;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JvmObjectRef {
+    /// The `generation` of the [`JvmInstancesResult`] the object came from.
+    pub generation: u64,
+    pub id: ObjectId,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "kind", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmInspectUnavailable {
+    /// The session has no inspector: not a JVM session, not ready yet, or turned off.
+    NoBackend,
+    /// The debug adapter lacks what the inspector needs; turned off for the session.
+    Unsupported {
+        detail: String,
+    },
+    NotSuspended,
+    /// The object is from an earlier stop, or the program stopped or resumed meanwhile.
+    Stale,
+    Collected,
+    ClassNotLoaded,
+    VmNotFound,
+    /// Transient: ask again.
+    TimedOut,
+    BackendClosed,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "status", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmInstancesResult {
+    Ready {
+        /// Goes into the [`JvmObjectRef`] of each instance.
+        generation: u64,
+        instances: Vec<JvmValue>,
+        /// The limit was reached; there may be more.
+        truncated: bool,
+    },
+    Unavailable {
+        reason: JvmInspectUnavailable,
+    },
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "status", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmFieldsResult {
+    Ready { fields: Vec<JvmField> },
+    Unavailable { reason: JvmInspectUnavailable },
+}
+
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(tag = "status", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmReferrersResult {
+    Ready { referrers: Vec<JvmReferrer>, truncated: bool },
+    Unavailable { reason: JvmInspectUnavailable },
+}
+
+/// The session's JVM for the inspector: java-debug's VM is found by the launched program's pid
+/// or by the port of an attach (the thread lists of two JVMs can be identical).
+pub(crate) fn vm_target(s: &Session) -> VmTarget {
+    let (pid, attach) = if s.request == "launch" {
+        (u32::try_from(launch_pid(s)).ok().filter(|&p| p > 0), None)
+    } else {
+        (None, s.attach_target.get())
+    };
+    VmTarget {
+        pid,
+        attach_host: attach.map(|(host, _)| host.clone()).filter(|h| !h.is_empty()),
+        attach_port: attach.map(|&(_, port)| port),
+        generation: s.suspended.ticket(),
+    }
+}
+
+pub(crate) fn set_inspector(s: &Session, inspector: Arc<dyn JvmInspector>) {
+    *s.jvm_inspector.lock() = Some(inspector);
+    s.emit(DebugEvent::Capabilities);
+}
+
+pub(crate) async fn instances(s: &Session, class_name: &str, limit: u32) -> IdeResult<JvmInstancesResult> {
+    let limit = limit.clamp(1, MAX_INSTANCES);
+    let call = match Call::begin(s, None).await {
+        Ok(call) => call,
+        Err(reason) => return Ok(JvmInstancesResult::Unavailable { reason }),
+    };
+    let generation = call.target.generation;
+    let result = call.run(call.inspector.instances(&call.target, class_name, limit)).await;
+    Ok(match settle(call.finish(result))? {
+        Ok(instances) => {
+            JvmInstancesResult::Ready { generation, truncated: instances.len() >= limit as usize, instances }
+        }
+        Err(reason) => JvmInstancesResult::Unavailable { reason },
+    })
+}
+
+pub(crate) async fn fields(s: &Session, object: JvmObjectRef) -> IdeResult<JvmFieldsResult> {
+    let call = match Call::begin(s, Some(object.generation)).await {
+        Ok(call) => call,
+        Err(reason) => return Ok(JvmFieldsResult::Unavailable { reason }),
+    };
+    let result = call.run(call.inspector.fields(&call.target, object.id)).await;
+    Ok(match settle(call.finish(result))? {
+        Ok(fields) => JvmFieldsResult::Ready { fields },
+        Err(reason) => JvmFieldsResult::Unavailable { reason },
+    })
+}
+
+pub(crate) async fn referrers(s: &Session, object: JvmObjectRef, limit: u32) -> IdeResult<JvmReferrersResult> {
+    let limit = if limit == 0 { DEFAULT_REFERRERS } else { limit.min(MAX_REFERRERS) };
+    let call = match Call::begin(s, Some(object.generation)).await {
+        Ok(call) => call,
+        Err(reason) => return Ok(JvmReferrersResult::Unavailable { reason }),
+    };
+    let result = call.run(call.inspector.referrers(&call.target, object.id, limit)).await;
+    Ok(match settle(call.finish(result))? {
+        Ok(referrers) => JvmReferrersResult::Ready { truncated: referrers.len() >= limit as usize, referrers },
+        Err(reason) => JvmReferrersResult::Unavailable { reason },
+    })
+}
+
+/// One inspector request. Holds the session's inspect lock and a clone of its inspector, which
+/// [`Call::run`] lets go of when the session ends.
+pub(super) struct Call<'s> {
+    session: &'s Session,
+    pub(super) inspector: Arc<dyn JvmInspector>,
+    pub(super) target: VmTarget,
+    _turn: tokio::sync::MutexGuard<'s, ()>,
+}
+
+impl<'s> Call<'s> {
+    /// `object_generation`: the stop the request's object was read in.
+    pub(super) async fn begin(
+        s: &'s Session,
+        object_generation: Option<u64>,
+    ) -> Result<Call<'s>, JvmInspectUnavailable> {
+        // Checked under the lock: a request queued behind another must see the state it runs in.
+        let turn = s.inspect_lock.lock().await;
+        let Some(inspector) = s.jvm_inspector.lock().clone() else {
+            return Err(JvmInspectUnavailable::NoBackend);
+        };
+        if !s.suspended.get() {
+            return Err(JvmInspectUnavailable::NotSuspended);
+        }
+        let target = vm_target(s);
+        if object_generation.is_some_and(|g| g != target.generation) {
+            return Err(JvmInspectUnavailable::Stale);
+        }
+        Ok(Call { session: s, inspector, target, _turn: turn })
+    }
+
+    pub(super) async fn run<T>(&self, request: InspectFuture<'_, T>) -> Result<T, InspectError> {
+        tokio::select! {
+            result = request => result,
+            () = self.session.ended.cancelled() => Err(InspectError::Closed),
+        }
+    }
+
+    /// The result unless the program stopped or resumed while it was read: a request of several
+    /// commands can straddle a stop. `Unsupported` turns the backend off.
+    pub(super) fn finish<T>(self, result: Result<T, InspectError>) -> Result<T, InspectError> {
+        let s = self.session;
+        match result {
+            Err(InspectError::Unsupported(detail)) => {
+                turn_off(s, &self.inspector, &detail);
+                Err(InspectError::Unsupported(detail))
+            }
+            _ if !s.suspended.get() || s.suspended.ticket() != self.target.generation => Err(InspectError::Stale),
+            result => result,
+        }
+    }
+}
+
+/// An adapter that lacks what the inspector needs will not gain it during the session.
+fn turn_off(s: &Session, inspector: &Arc<dyn JvmInspector>, detail: &str) {
+    let removed = {
+        let mut slot = s.jvm_inspector.lock();
+        // Not one installed since this request began.
+        let current = slot.as_ref().is_some_and(|i| std::ptr::addr_eq(Arc::as_ptr(i), Arc::as_ptr(inspector)));
+        current && slot.take().is_some()
+    };
+    if removed {
+        s.emit(DebugEvent::JvmBackend { state: JvmBackendState::Unsupported { detail: detail.to_owned() } });
+        s.emit(DebugEvent::Capabilities);
+    }
+}
+
+/// A failure the inspector could not classify is an error, not a reason shown to the user.
+fn settle<T>(result: Result<T, InspectError>) -> IdeResult<Result<T, JvmInspectUnavailable>> {
+    use JvmInspectUnavailable as U;
+    let error = match result {
+        Ok(value) => return Ok(Ok(value)),
+        Err(error) => error,
+    };
+    Ok(Err(match error {
+        InspectError::NotSuspended => U::NotSuspended,
+        InspectError::Stale => U::Stale,
+        InspectError::Collected => U::Collected,
+        InspectError::ClassNotLoaded => U::ClassNotLoaded,
+        InspectError::VmNotFound => U::VmNotFound,
+        InspectError::Unsupported(detail) => U::Unsupported { detail },
+        // Also the Kotlin link's `Busy`: the backend stays.
+        InspectError::TimedOut => U::TimedOut,
+        InspectError::Closed => U::BackendClosed,
+        InspectError::Failed(message) => return Err(IdeError::internal(format!("JVM inspector: {message}"))),
+    }))
+}
+
+/// Reports a Kotlin link that stops inspecting or closes. Holds neither the link nor the
+/// session: it ends once the session drops the link, and never drops it itself (after
+/// `VirtualMachine.Dispose` the link is closed but still forwarding the reply).
+pub(crate) fn watch_link(s: &Arc<Session>, link: &ide_jdwp::JdwpLink) {
+    let mut states = link.subscribe();
+    let session = Arc::downgrade(s);
+    tokio::spawn(async move {
+        let mut reported = None;
+        loop {
+            let state = match &*states.borrow_and_update() {
+                ide_jdwp::LinkState::Degraded(detail) => Some(JvmBackendState::Degraded { detail: detail.clone() }),
+                ide_jdwp::LinkState::Closed => Some(JvmBackendState::Closed),
+                _ => None,
+            };
+            if let Some(state) = state
+                && reported.as_ref() != Some(&state)
+            {
+                let Some(s) = session.upgrade() else { return };
+                if s.ended.is_cancelled() || s.terminated.load(std::sync::atomic::Ordering::Acquire) {
+                    return;
+                }
+                s.emit(DebugEvent::JvmBackend { state: state.clone() });
+                reported = Some(state);
+            }
+            if states.changed().await.is_err() {
+                return;
+            }
+        }
+    });
+}

crates/ide-dap/src/jvm_memory/mod.rs

@@ -0,0 +1,338 @@
+//! Class-table snapshots of a debugged JVM, read over the HotSpot attach listener or, where
+//! that is unavailable, counted by the debugger; and the JVM's objects through the debugger.
+
+mod fallback;
+mod heap;
+mod inspect;
+mod scan;
+mod snapshot;
+#[cfg(test)]
+pub(crate) mod test_support;
+#[cfg(test)]
+mod tests;
+
+use crate::session::Session;
+use crate::session::Suspension;
+use ide_core::IdeResult;
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::HashMap;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicI64, Ordering};
+use std::time::Duration;
+
+pub use heap::*;
+pub use inspect::{JvmFieldsResult, JvmInspectUnavailable, JvmInstancesResult, JvmObjectRef, JvmReferrersResult};
+pub(crate) use inspect::{fields, instances, referrers, set_inspector, watch_link};
+#[cfg(all(test, unix))]
+pub(crate) use scan::watch_for_attached_jvm;
+pub(crate) use scan::{JvmFinder, attach_target, find_attached_jvm, find_local_jvm, local_jdwp_port};
+use snapshot::{AttachProbe, JdkProbe, take_snapshot};
+
+pub const JVM_MEMORY_ADAPTERS: &[&str] = &["java-debug", crate::kotlin::ADAPTER];
+pub const HISTOGRAM_TIMEOUT: Duration = Duration::from_secs(10);
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JvmClassRow {
+    pub name: String,
+    pub module: Option<String>,
+    pub instances: u64,
+    pub bytes: u64,
+    /// Change since the previous snapshot; `None` on the first one and for ambiguous rows.
+    pub delta_instances: Option<i64>,
+    pub delta_bytes: Option<i64>,
+    /// Several classes share this name (different class loaders), so it has no delta.
+    pub ambiguous: bool,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JvmMemorySnapshot {
+    /// Largest `bytes` first.
+    pub rows: Vec<JvmClassRow>,
+    pub total_instances: u64,
+    pub total_bytes: u64,
+    /// Empty when unknown.
+    pub java_version: String,
+    pub taken_while_suspended: bool,
+    /// A previous snapshot from the same source exists; deltas are against it.
+    pub has_baseline: bool,
+    /// Wall time of the histogram or count request.
+    pub elapsed_ms: u32,
+    pub source: JvmMemorySource,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum JvmMemorySource {
+    /// `GC.class_histogram -all`: sizes, and objects not yet collected.
+    Histogram,
+    /// JDWP `InstanceCounts`: reachable objects only, no sizes (`bytes` is 0).
+    Debugger,
+}
+
+#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(tag = "kind", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmMemoryUnavailable {
+    /// An attach session whose JVM is remote, or local but not found by its JDWP port.
+    AttachedJvmNotFound,
+    /// An attach through the IDE's listen-mode relay: the JVM connected to the IDE, so it has
+    /// no JDWP listener to be found by.
+    ListenModeNotSupported,
+    UnsupportedPlatform,
+    NoJvmProcess,
+    ListenerNotRunning,
+    /// `java_major` is 0 when the version is unknown.
+    UnsafeWhileSuspended {
+        java_major: u32,
+    },
+    ProgramExited,
+    TimedOut,
+}
+
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(tag = "status", rename_all = "camelCase", rename_all_fields = "camelCase")]
+pub enum JvmMemoryResult {
+    Ready {
+        snapshot: JvmMemorySnapshot,
+    },
+    Unavailable {
+        reason: JvmMemoryUnavailable,
+        /// The debugger could count the classes if the program were paused.
+        can_count_when_paused: bool,
+    },
+}
+
+/// Instances and bytes per class name, for the next snapshot's deltas; `None` for a name
+/// several classes shared, so it gets no delta next time either.
+type ClassCounts = HashMap<String, Option<(u64, u64)>>;
+
+/// Per-session baseline; its mutex also keeps one class-table request per session at a time.
+#[derive(Default)]
+pub struct JvmMemoryState {
+    /// Shared with the blocking task, so a task that panics leaves it in place.
+    previous: Option<(JvmMemorySource, Arc<ClassCounts>)>,
+}
+
+impl JvmMemoryState {
+    /// The previous snapshot's counts if it came from `source`: counts from the other source
+    /// are not comparable (only reachable objects versus all of them).
+    pub(crate) fn baseline(&self, source: JvmMemorySource) -> Option<Arc<ClassCounts>> {
+        self.previous.as_ref().filter(|(s, _)| *s == source).map(|(_, counts)| counts.clone())
+    }
+
+    pub(crate) fn remember(&mut self, source: JvmMemorySource, counts: ClassCounts) {
+        self.previous = Some((source, Arc::new(counts)));
+    }
+}
+
+pub(crate) async fn session_classes(session: Arc<Session>) -> IdeResult<JvmMemoryResult> {
+    until_located(&session).await;
+    let launched = histogram_pid(&session);
+    // Detached, so a caller that gives up cannot release the lock while the JVM is still
+    // answering and let a second histogram request run next to it.
+    tokio::spawn(async move {
+        let target = session_target(&session, launched);
+        let probe = |suspended| -> Arc<dyn AttachProbe> { Arc::new(JdkProbe { suspended }) };
+        snapshot(&session.jvm_memory, &session.suspended, probe, target, Some(&session)).await
+    })
+    .await
+    .map_err(|e| ide_core::IdeError::internal(format!("JVM memory snapshot failed: {e}")))?
+}
+
+/// Bounds the wait of [`until_located`]; `configure` has its own timeouts, this only guards them.
+const LOCATE_WAIT: Duration = Duration::from_secs(30);
+
+/// Until `configure` has recorded where `session`'s JVM is. The Memory view asks as soon as the
+/// session appears; looked up earlier, an attached JVM is reported as missing.
+async fn until_located(session: &Session) {
+    let mut located = session.jvm_located.subscribe();
+    tokio::select! {
+        _ = located.wait_for(|v| *v) => {}
+        () = session.ended.cancelled() => {}
+        () = tokio::time::sleep(LOCATE_WAIT) => {}
+    }
+}
+
+/// `launched`: [`histogram_pid`] of `session`.
+fn session_target(session: &Session, launched: Result<Option<i32>, JvmMemoryUnavailable>) -> JvmTarget<'_> {
+    match launched {
+        Ok(Some(pid)) => JvmTarget::Launched(pid),
+        Ok(None) => JvmTarget::Attached { pid: &session.jvm_pid, jdwp_port: session.jdwp_port.get().copied() },
+        Err(reason) => JvmTarget::Unavailable(reason),
+    }
+}
+
+/// The pid of a launch session's program (`None` for an attach session), or why no histogram
+/// can be taken.
+fn histogram_pid(session: &Session) -> Result<Option<i32>, JvmMemoryUnavailable> {
+    if !JVM_MEMORY_ADAPTERS.contains(&session.adapter.as_str()) {
+        return Err(JvmMemoryUnavailable::NoJvmProcess);
+    }
+    if !cfg!(unix) {
+        return Err(JvmMemoryUnavailable::UnsupportedPlatform);
+    }
+    if session.request == "launch" {
+        return match i32::try_from(launch_pid(session)).ok().filter(|&p| p > 0) {
+            Some(pid) => Ok(Some(pid)),
+            None => Err(JvmMemoryUnavailable::NoJvmProcess),
+        };
+    }
+    if session.jvm_pid.load(Ordering::Acquire) <= 0 {
+        if session.terminated.load(Ordering::Acquire) {
+            return Err(JvmMemoryUnavailable::ProgramExited);
+        }
+        if session.listen_relay.load(Ordering::Acquire) {
+            return Err(JvmMemoryUnavailable::ListenModeNotSupported);
+        }
+    }
+    Ok(None)
+}
+
+/// The JVM a launch session started: the one the IDE started for an app-launched (Kotlin)
+/// session, else the program the adapter reported; 0 when neither is known.
+pub(crate) fn launch_pid(session: &Session) -> i64 {
+    match session.jvm_pid.load(Ordering::Acquire) {
+        p if p > 0 => p,
+        _ => session.debuggee_pid.load(Ordering::Acquire),
+    }
+}
+
+#[derive(Clone, Copy)]
+pub(crate) enum JvmTarget<'a> {
+    /// The program a launch session started: its pid and everything it started.
+    Launched(i32),
+    /// The JVM of an attach session. While `pid` is 0 it is looked up by `jdwp_port`, which is
+    /// `None` for a remote JVM.
+    Attached { pid: &'a AtomicI64, jdwp_port: Option<u16> },
+    /// Known without asking any JVM: no histogram can be taken, for this reason.
+    Unavailable(JvmMemoryUnavailable),
+}
+
+enum Lookup {
+    Tree(i32),
+    Known(i32),
+    Scan(u16),
+}
+
+/// `probe` is built from the suspension read once the lock is held: a request queued behind
+/// another must not decide on a state from before the program hit a breakpoint. Where no
+/// histogram can be taken, `debugger` (the session) may count the classes instead.
+pub(crate) async fn snapshot(
+    state: &tokio::sync::Mutex<JvmMemoryState>,
+    suspended: &Suspension,
+    probe: impl FnOnce(bool) -> Arc<dyn AttachProbe>,
+    target: JvmTarget<'_>,
+    debugger: Option<&Session>,
+) -> IdeResult<JvmMemoryResult> {
+    let mut state = state.lock().await;
+    let outcome = histogram(&mut state, suspended, probe, target).await?;
+    fallback::or_debugger_counts(&mut state, outcome, debugger).await
+}
+
+async fn histogram(
+    state: &mut JvmMemoryState,
+    suspended: &Suspension,
+    probe: impl FnOnce(bool) -> Arc<dyn AttachProbe>,
+    target: JvmTarget<'_>,
+) -> IdeResult<Result<JvmMemorySnapshot, JvmMemoryUnavailable>> {
+    let suspended = suspended.get();
+    let lookup = match lookup(target) {
+        Ok(lookup) => lookup,
+        Err(reason) => return Ok(Err(reason)),
+    };
+    let probe = probe(suspended);
+    let previous = state.baseline(JvmMemorySource::Histogram);
+    let (found, outcome) = tokio::task::spawn_blocking(move || match resolve_jvm(lookup, &*probe, suspended) {
+        Ok((tree, found)) => (found, take_snapshot(&*probe, &tree, suspended, previous.as_deref())),
+        Err(reason) => (None, Ok(Err(reason))),
+    })
+    .await
+    .map_err(|e| ide_core::IdeError::internal(format!("JVM memory snapshot failed: {e}")))?;
+    keep_found(target, found);
+    Ok(outcome?.map(|(snapshot, counts)| {
+        state.remember(JvmMemorySource::Histogram, counts);
+        snapshot
+    }))
+}
+
+/// Where to look for `target`'s JVM, or why there is none to ask.
+fn lookup(target: JvmTarget<'_>) -> Result<Lookup, JvmMemoryUnavailable> {
+    match target {
+        JvmTarget::Launched(pid) => Ok(Lookup::Tree(pid)),
+        JvmTarget::Attached { pid, jdwp_port } => match i32::try_from(pid.load(Ordering::Acquire)) {
+            Ok(p) if p > 0 => Ok(Lookup::Known(p)),
+            _ => jdwp_port.map(Lookup::Scan).ok_or(JvmMemoryUnavailable::AttachedJvmNotFound),
+        },
+        JvmTarget::Unavailable(reason) => Err(reason),
+    }
+}
+
+/// Blocking. The pids to pick the JVM from, and the pid a scan found (for [`keep_found`]).
+fn resolve_jvm(
+    lookup: Lookup,
+    probe: &dyn AttachProbe,
+    suspended: bool,
+) -> Result<(Vec<i32>, Option<i32>), JvmMemoryUnavailable> {
+    match lookup {
+        Lookup::Tree(pid) => Ok((pid_tree(pid), None)),
+        Lookup::Known(pid) => Ok((vec![pid], None)),
+        Lookup::Scan(port) => scan_for_jvm(probe, port, suspended).map(|pid| (vec![pid], Some(pid))),
+    }
+}
+
+fn keep_found(target: JvmTarget<'_>, found: Option<i32>) {
+    if let (Some(found), JvmTarget::Attached { pid, .. }) = (found, target) {
+        // The attach-time scan may have found it meanwhile; either answer is the same JVM.
+        let _ = pid.compare_exchange(0, i64::from(found), Ordering::AcqRel, Ordering::Acquire);
+    }
+}
+
+/// A suspended JDK below 17 hangs on an attach request, so while suspended only a JVM known to
+/// be 17 or later is asked anything. Pass a version read without attaching (the `release` file).
+fn safe_while_suspended(version: Option<&ide_jvm_attach::JavaVersion>) -> bool {
+    version.is_some_and(|v| ide_jvm_attach::histogram_safe_while_suspended(v.major))
+}
+
+/// The JVM listening on JDWP `port`. While suspended the scan reaches the session's own JVM
+/// too, so JVMs unsafe to ask are skipped, and when one of them may be the session's the
+/// answer is a refusal rather than "not found".
+fn scan_for_jvm(probe: &dyn AttachProbe, port: u16, suspended: bool) -> Result<i32, JvmMemoryUnavailable> {
+    // Majors of the JVMs left out; 0 for an unknown version.
+    let skipped = std::cell::RefCell::new(std::collections::BTreeSet::new());
+    let may_query = |pid: u32| {
+        if !suspended {
+            return true;
+        }
+        let version = probe.version(pid);
+        let safe = safe_while_suspended(version.as_ref());
+        if !safe {
+            skipped.borrow_mut().insert(version.map_or(0, |v| v.major));
+        }
+        safe
+    };
+    match probe.find_by_jdwp_port(port, &may_query).and_then(|p| i32::try_from(p).ok()) {
+        Some(pid) if pid > 0 => Ok(pid),
+        _ => {
+            let skipped = skipped.into_inner();
+            Err(match skipped.first() {
+                None => JvmMemoryUnavailable::AttachedJvmNotFound,
+                Some(&major) => JvmMemoryUnavailable::UnsafeWhileSuspended {
+                    java_major: if skipped.len() == 1 { major } else { 0 },
+                },
+            })
+        }
+    }
+}
+
+fn pid_tree(pid: i32) -> Vec<i32> {
+    #[cfg(unix)]
+    {
+        ide_core::process::process_tree(pid)
+    }
+    #[cfg(not(unix))]
+    {
+        vec![pid]
+    }
+}

crates/ide-dap/src/jvm_memory/scan.rs

@@ -0,0 +1,146 @@
+//! Finding the JVM behind an attach session by its JDWP port.
+
+use super::safe_while_suspended;
+use crate::session::Session;
+use serde_json::Value;
+use std::net::IpAddr;
+use std::sync::Arc;
+use std::sync::atomic::Ordering;
+use std::time::Duration;
+
+/// One try of the scan at attach time, and the limit per socket within it: a silent socket's
+/// query thread lives that long, so a longer per-socket limit piles threads up across tries.
+const ATTACH_SCAN_TRY: Duration = Duration::from_millis(500);
+const ATTACH_SCAN_INTERVAL: Duration = Duration::from_millis(150);
+/// The JVM's attach socket can appear a little after the JDWP "Listening" banner, which is
+/// when the IDE attaches.
+const ATTACH_SCAN_WINDOW: Duration = Duration::from_secs(3);
+/// The single scan a refresh makes while the attach-time one found nothing.
+pub(super) const RESCAN_PER_SOCKET: Duration = Duration::from_secs(1);
+pub(super) const RESCAN_BUDGET: Duration = Duration::from_secs(2);
+
+/// JDWP port of an attach to this machine (`hostName` loopback or absent): only such a JVM has
+/// an attach socket the IDE can find.
+pub(crate) fn local_jdwp_port(arguments: &Value) -> Option<u16> {
+    let local = match arguments.get("hostName") {
+        None | Some(Value::Null) => true,
+        Some(Value::String(host)) => {
+            let host = host.trim();
+            let ip = host.strip_prefix('[').and_then(|h| h.strip_suffix(']')).unwrap_or(host);
+            host.eq_ignore_ascii_case("localhost") || ip.parse::<IpAddr>().is_ok_and(|ip| ip.is_loopback())
+        }
+        Some(_) => false,
+    };
+    jdwp_port(arguments).filter(|_| local)
+}
+
+/// `port` of an attach request: a number or a numeric string, never 0.
+fn jdwp_port(arguments: &Value) -> Option<u16> {
+    let port = match arguments.get("port")? {
+        Value::Number(n) => n.as_u64().and_then(|p| u16::try_from(p).ok()),
+        Value::String(s) => s.trim().parse().ok(),
+        _ => None,
+    };
+    port.filter(|&p| p != 0)
+}
+
+/// `hostName` (empty when absent) and `port` of an attach request, local or not.
+pub(crate) fn attach_target(arguments: &Value) -> Option<(String, u16)> {
+    let host = arguments.get("hostName").and_then(Value::as_str).unwrap_or_default();
+    Some((host.to_owned(), jdwp_port(arguments)?))
+}
+
+/// Pid of the local JVM listening on a JDWP port (first argument), given whether the session is
+/// suspended (second). Replaceable so tests never send attach requests to real JVMs.
+pub(crate) type JvmFinder = Arc<dyn Fn(u16, bool) -> Option<u32> + Send + Sync>;
+
+/// The [`JvmFinder`] of the attach-time scan.
+pub(crate) fn find_local_jvm(port: u16, suspended: bool) -> Option<u32> {
+    let may_query = |pid| !suspended || safe_while_suspended(ide_jvm_attach::java_version_of(pid).as_ref());
+    ide_jvm_attach::find_jvm_by_jdwp_port(port, ATTACH_SCAN_TRY, ATTACH_SCAN_TRY, may_query)
+}
+
+/// Looks for the JVM behind a local attach: one try now, the rest in the background, so a JVM
+/// that never opens an attach socket holds the attach up by one try at most. Call it before the
+/// debugger connects: the JVM clears its JDWP listener address then, and a scan can no longer
+/// tell it by its port.
+pub(crate) async fn find_attached_jvm(session: &Arc<Session>, port: u16, finder: JvmFinder) {
+    let _ = session.jdwp_port.set(port);
+    let find = move |suspended: bool| finder(port, suspended);
+    let first = find.clone();
+    if let Ok(Some(pid)) = tokio::task::spawn_blocking(move || first(false)).await {
+        let _ = session.jvm_pid.compare_exchange(0, i64::from(pid), Ordering::AcqRel, Ordering::Acquire);
+        return;
+    }
+    drop(watch_for_attached_jvm(session, port, find, ATTACH_SCAN_INTERVAL, ATTACH_SCAN_WINDOW));
+}
+
+/// Retries `find` for the session's `jvm_pid`, holding the session weakly so an ended session
+/// is not kept alive. `find` is told whether the session is suspended.
+pub(crate) fn watch_for_attached_jvm<F>(
+    session: &Arc<Session>,
+    port: u16,
+    find: F,
+    interval: Duration,
+    window: Duration,
+) -> tokio::task::JoinHandle<()>
+where
+    F: Fn(bool) -> Option<u32> + Clone + Send + 'static,
+{
+    let weak = Arc::downgrade(session);
+    tokio::spawn(async move {
+        let gate = || match weak.upgrade() {
+            Some(s) if !s.terminated.load(Ordering::Acquire) && !s.conn.is_closed() => {
+                if s.jvm_pid.load(Ordering::Acquire) > 0 {
+                    ScanGate::Ended
+                } else {
+                    ScanGate::Scan { suspended: s.suspended.get() }
+                }
+            }
+            _ => ScanGate::Ended,
+        };
+        let Some(pid) = retry_find(find, gate, interval, window).await else {
+            tracing::debug!("no local JVM found for JDWP port {port} yet");
+            return;
+        };
+        if let Some(s) = weak.upgrade() {
+            let _ = s.jvm_pid.compare_exchange(0, i64::from(pid), Ordering::AcqRel, Ordering::Acquire);
+        }
+    })
+}
+
+#[derive(Clone, Copy, Debug, PartialEq)]
+pub(crate) enum ScanGate {
+    Scan { suspended: bool },
+    Ended,
+}
+
+/// Calls `find` on a blocking thread, on each try `gate` allows, until it returns a pid, `gate`
+/// reports the end or `window` has passed.
+pub(crate) async fn retry_find<F>(
+    find: F,
+    gate: impl Fn() -> ScanGate,
+    interval: Duration,
+    window: Duration,
+) -> Option<u32>
+where
+    F: Fn(bool) -> Option<u32> + Clone + Send + 'static,
+{
+    let deadline = tokio::time::Instant::now() + window;
+    loop {
+        match gate() {
+            ScanGate::Ended => break,
+            ScanGate::Scan { suspended } => {
+                let find = find.clone();
+                if let Ok(Some(pid)) = tokio::task::spawn_blocking(move || find(suspended)).await {
+                    return Some(pid);
+                }
+            }
+        }
+        if tokio::time::Instant::now() + interval >= deadline {
+            break;
+        }
+        tokio::time::sleep(interval).await;
+    }
+    None
+}

crates/ide-dap/src/jvm_memory/snapshot.rs

@@ -0,0 +1,214 @@
+//! One class histogram of a JVM and its deltas against the previous one.
+
+use super::scan::{RESCAN_BUDGET, RESCAN_PER_SOCKET};
+use super::{
+    ClassCounts, HISTOGRAM_TIMEOUT, JvmClassRow, JvmMemorySnapshot, JvmMemorySource, JvmMemoryUnavailable,
+    safe_while_suspended,
+};
+use ide_core::IdeResult;
+use ide_jvm_attach::{AttachError, HeapDumpReply, HistogramRow, JavaVersion};
+use std::collections::HashMap;
+use std::path::Path;
+use std::time::Duration;
+
+/// Version probe for a JVM whose `release` file could not be read.
+const VERSION_TIMEOUT: Duration = Duration::from_secs(2);
+const FLAGS_TIMEOUT: Duration = Duration::from_secs(2);
+
+/// The attach calls a snapshot or a heap dump makes, so tests can stand in for a JVM.
+pub(crate) trait AttachProbe: Send + Sync {
+    fn has_listener(&self, pid: u32) -> bool;
+    /// Asks only the JVMs whose pid `may_query` accepts.
+    fn find_by_jdwp_port(&self, port: u16, may_query: &dyn Fn(u32) -> bool) -> Option<u32>;
+    fn version(&self, pid: u32) -> Option<JavaVersion>;
+    fn histogram(&self, pid: u32) -> Result<String, AttachError>;
+    fn alive(&self, pid: u32) -> bool;
+    fn vm_flags(&self, pid: u32) -> Result<String, AttachError>;
+    fn heap_dump(&self, pid: u32, path: &Path, timeout: Duration) -> Result<HeapDumpReply, AttachError>;
+    /// `None` where the free space is not known.
+    fn free_bytes(&self, dir: &Path) -> Option<u64>;
+}
+
+pub(super) struct JdkProbe {
+    pub(super) suspended: bool,
+}
+
+impl AttachProbe for JdkProbe {
+    fn has_listener(&self, pid: u32) -> bool {
+        ide_jvm_attach::has_listener(pid)
+    }
+
+    fn find_by_jdwp_port(&self, port: u16, may_query: &dyn Fn(u32) -> bool) -> Option<u32> {
+        ide_jvm_attach::find_jvm_by_jdwp_port(port, RESCAN_PER_SOCKET, RESCAN_BUDGET, may_query)
+    }
+
+    fn version(&self, pid: u32) -> Option<JavaVersion> {
+        ide_jvm_attach::java_version_of(pid).or_else(|| {
+            // The version decides whether attaching to a suspended VM hangs it, so never
+            // attach to learn it while suspended.
+            if self.suspended {
+                return None;
+            }
+            let out = ide_jvm_attach::jcmd(pid, "VM.version", VERSION_TIMEOUT).ok()?;
+            ide_jvm_attach::parse_vm_version(&out)
+        })
+    }
+
+    fn histogram(&self, pid: u32) -> Result<String, AttachError> {
+        ide_jvm_attach::jcmd(pid, "GC.class_histogram -all", HISTOGRAM_TIMEOUT)
+    }
+
+    fn alive(&self, pid: u32) -> bool {
+        alive(pid)
+    }
+
+    fn vm_flags(&self, pid: u32) -> Result<String, AttachError> {
+        ide_jvm_attach::vm_flags(pid, FLAGS_TIMEOUT)
+    }
+
+    fn heap_dump(&self, pid: u32, path: &Path, timeout: Duration) -> Result<HeapDumpReply, AttachError> {
+        ide_jvm_attach::heap_dump(pid, path, timeout)
+    }
+
+    fn free_bytes(&self, dir: &Path) -> Option<u64> {
+        ide_heap::free_bytes(dir)
+    }
+}
+
+fn alive(pid: u32) -> bool {
+    #[cfg(unix)]
+    {
+        // 0 and negative pids address process groups.
+        let Ok(pid) = i32::try_from(pid) else { return false };
+        // SAFETY: signal 0 only checks that the process exists and may be signalled.
+        pid > 0
+            && (unsafe { libc::kill(pid, 0) } == 0
+                || std::io::Error::last_os_error().raw_os_error() == Some(libc::EPERM))
+    }
+    #[cfg(not(unix))]
+    {
+        let _ = pid;
+        false
+    }
+}
+
+/// Why `pid`'s attach listener cannot answer: it stopped listening or the program ended.
+pub(super) fn gone(probe: &dyn AttachProbe, pid: u32) -> JvmMemoryUnavailable {
+    if probe.alive(pid) { JvmMemoryUnavailable::ListenerNotRunning } else { JvmMemoryUnavailable::ProgramExited }
+}
+
+/// The reason for an attach request (`what`) to `jvm` that failed, or an error where no reason
+/// fits.
+pub(super) fn attach_failure(
+    probe: &dyn AttachProbe,
+    jvm: u32,
+    error: AttachError,
+    what: &str,
+) -> IdeResult<JvmMemoryUnavailable> {
+    use JvmMemoryUnavailable as U;
+    match error {
+        AttachError::Timeout => Ok(U::TimedOut),
+        AttachError::Refused | AttachError::NoListener => Ok(gone(probe, jvm)),
+        AttachError::ForeignListener => {
+            tracing::warn!("attach socket of JVM {jvm} is no longer private to this user; not using it");
+            Ok(U::ListenerNotRunning)
+        }
+        AttachError::Unsupported => Ok(U::UnsupportedPlatform),
+        e => Err(ide_core::IdeError::internal(format!("{what} of JVM {jvm}: {e}"))),
+    }
+}
+
+pub(crate) fn pick_jvm_pid(tree: &[i32], has_listener: impl Fn(u32) -> bool) -> Option<u32> {
+    tree.iter().filter_map(|&p| u32::try_from(p).ok()).filter(|&p| p > 0).find(|&p| has_listener(p))
+}
+
+pub(crate) fn diff_rows(rows: Vec<HistogramRow>, previous: Option<&ClassCounts>) -> (Vec<JvmClassRow>, ClassCounts) {
+    let mut seen: HashMap<&str, u32> = HashMap::with_capacity(rows.len());
+    for r in &rows {
+        *seen.entry(r.name.as_str()).or_default() += 1;
+    }
+    let ambiguous: Vec<bool> = rows.iter().map(|r| seen[r.name.as_str()] > 1).collect();
+    drop(seen);
+
+    let mut counts = ClassCounts::with_capacity(rows.len());
+    let mut out: Vec<JvmClassRow> = rows
+        .into_iter()
+        .zip(ambiguous)
+        .map(|(r, ambiguous)| {
+            counts.insert(r.name.clone(), (!ambiguous).then_some((r.instances, r.bytes)));
+            let delta = match previous {
+                _ if ambiguous => None,
+                None => None,
+                Some(p) => match p.get(&r.name) {
+                    Some(None) => None,
+                    // Absent: new since the previous snapshot, so it grew from nothing.
+                    before => {
+                        let (instances, bytes) = before.copied().flatten().unwrap_or_default();
+                        Some((delta(r.instances, instances), delta(r.bytes, bytes)))
+                    }
+                },
+            };
+            JvmClassRow {
+                name: r.name,
+                module: r.module,
+                instances: r.instances,
+                bytes: r.bytes,
+                delta_instances: delta.map(|d| d.0),
+                delta_bytes: delta.map(|d| d.1),
+                ambiguous,
+            }
+        })
+        .collect();
+    out.sort_by(|a, b| b.bytes.cmp(&a.bytes).then_with(|| a.name.cmp(&b.name)));
+    (out, counts)
+}
+
+/// Exact while the difference fits in an i64 (two's complement).
+fn delta(now: u64, before: u64) -> i64 {
+    now.wrapping_sub(before) as i64
+}
+
+/// `pid_tree` starts with the session's reported pid, followed by its descendants.
+pub(crate) fn take_snapshot(
+    probe: &dyn AttachProbe,
+    pid_tree: &[i32],
+    suspended: bool,
+    previous: Option<&ClassCounts>,
+) -> IdeResult<Result<(JvmMemorySnapshot, ClassCounts), JvmMemoryUnavailable>> {
+    use JvmMemoryUnavailable as U;
+    let Some(root) = pid_tree.first().and_then(|&p| u32::try_from(p).ok()) else {
+        return Ok(Err(U::NoJvmProcess));
+    };
+    let Some(jvm) = pick_jvm_pid(pid_tree, |p| probe.has_listener(p)) else {
+        return Ok(Err(gone(probe, root)));
+    };
+
+    let version = probe.version(jvm);
+    if suspended && !safe_while_suspended(version.as_ref()) {
+        return Ok(Err(U::UnsafeWhileSuspended { java_major: version.map_or(0, |v| v.major) }));
+    }
+
+    let started = std::time::Instant::now();
+    let text = match probe.histogram(jvm) {
+        Ok(text) => text,
+        Err(e) => return attach_failure(probe, jvm, e, "class histogram").map(Err),
+    };
+    let elapsed_ms = u32::try_from(started.elapsed().as_millis()).unwrap_or(u32::MAX);
+
+    let histogram = ide_jvm_attach::parse_class_histogram(&text);
+    if histogram.skipped_lines > 0 {
+        tracing::debug!("class histogram of JVM {jvm}: {} unreadable lines", histogram.skipped_lines);
+    }
+    let (rows, counts) = diff_rows(histogram.rows, previous);
+    let snapshot = JvmMemorySnapshot {
+        total_instances: rows.iter().map(|r| r.instances).sum(),
+        total_bytes: rows.iter().map(|r| r.bytes).sum(),
+        rows,
+        java_version: version.map(|v| v.text).unwrap_or_default(),
+        taken_while_suspended: suspended,
+        has_baseline: previous.is_some(),
+        elapsed_ms,
+        source: JvmMemorySource::Histogram,
+    };
+    Ok(Ok((snapshot, counts)))
+}

crates/ide-dap/src/jvm_memory/test_support.rs

@@ -0,0 +1,119 @@
+//! A scripted [`JvmInspector`] and a session without an adapter behind it.
+
+use crate::SessionOwner;
+use crate::adapter::{AdapterSpec, Transport};
+use crate::connection::Connection;
+use crate::session::Session;
+use ide_core::{DebugSessionId, IdeEvent, SharedSink};
+use ide_jvm_inspect::{
+    ClassCount, InspectError, InspectFuture, JvmField, JvmInspector, JvmReferrer, JvmValue, ObjectId, VmTarget,
+};
+use parking_lot::Mutex;
+use std::sync::Arc;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use tokio::sync::Notify;
+
+#[derive(Default)]
+pub(crate) struct FakeInspector {
+    pub targets: Mutex<Vec<VmTarget>>,
+    /// The `limit` of each `instances` / `referrers` call.
+    pub limits: Mutex<Vec<u32>>,
+    pub calls: AtomicUsize,
+    /// Returned by every call when set.
+    pub error: Mutex<Option<InspectError>>,
+    pub counts: Mutex<Vec<ClassCount>>,
+    pub instances: Mutex<Vec<JvmValue>>,
+    /// Every call signals `entered`, then waits for `release`.
+    pub hold: bool,
+    pub entered: Notify,
+    pub release: Notify,
+}
+
+impl FakeInspector {
+    pub fn failing(error: InspectError) -> Self {
+        Self { error: Mutex::new(Some(error)), ..Self::default() }
+    }
+
+    pub fn calls(&self) -> usize {
+        self.calls.load(Ordering::SeqCst)
+    }
+
+    async fn answer<T: Send>(&self, target: &VmTarget, limit: Option<u32>, ok: T) -> Result<T, InspectError> {
+        self.calls.fetch_add(1, Ordering::SeqCst);
+        self.targets.lock().push(target.clone());
+        self.limits.lock().extend(limit);
+        if self.hold {
+            self.entered.notify_one();
+            self.release.notified().await;
+        }
+        match self.error.lock().clone() {
+            Some(e) => Err(e),
+            None => Ok(ok),
+        }
+    }
+}
+
+impl JvmInspector for FakeInspector {
+    fn class_counts<'a>(&'a self, target: &'a VmTarget) -> InspectFuture<'a, Vec<ClassCount>> {
+        Box::pin(self.answer(target, None, self.counts.lock().clone()))
+    }
+
+    fn instances<'a>(&'a self, target: &'a VmTarget, _: &'a str, limit: u32) -> InspectFuture<'a, Vec<JvmValue>> {
+        Box::pin(self.answer(target, Some(limit), self.instances.lock().clone()))
+    }
+
+    fn fields<'a>(&'a self, target: &'a VmTarget, _: ObjectId) -> InspectFuture<'a, Vec<JvmField>> {
+        Box::pin(self.answer(target, None, Vec::new()))
+    }
+
+    fn referrers<'a>(&'a self, target: &'a VmTarget, _: ObjectId, limit: u32) -> InspectFuture<'a, Vec<JvmReferrer>> {
+        Box::pin(self.answer(target, Some(limit), Vec::new()))
+    }
+}
+
+pub(crate) struct BareSession {
+    pub session: Arc<Session>,
+    pub events: Arc<Mutex<Vec<IdeEvent>>>,
+    /// The adapter's end of the connection, kept open.
+    _adapter: tokio::io::DuplexStream,
+}
+
+/// A java-debug session that no adapter answers; must be called inside a Tokio runtime.
+pub(crate) fn bare_session(request: &str) -> BareSession {
+    bare_session_of("java-debug", request)
+}
+
+/// A session of adapter `name` that no adapter answers; must be called inside a Tokio runtime.
+pub(crate) fn bare_session_of(name: &str, request: &str) -> BareSession {
+    let events: Arc<Mutex<Vec<IdeEvent>>> = Arc::default();
+    let sink_events = events.clone();
+    let sink: SharedSink = Arc::new(move |e: IdeEvent| sink_events.lock().push(e));
+    let (client, adapter) = tokio::io::duplex(1 << 10);
+    let (reader, writer) = tokio::io::split(client);
+    let (conn, _) = Connection::start(reader, writer);
+    let spec = AdapterSpec {
+        adapter: name.into(),
+        command: String::new(),
+        args: Vec::new(),
+        transport: Transport::Stdio,
+        install_hint: None,
+        cwd: std::env::temp_dir(),
+        env: Vec::new(),
+        server_host: None,
+        connect: None,
+        pinned: None,
+    };
+    let session = Session::new(
+        DebugSessionId(1),
+        SessionOwner::new("test", sink),
+        "test".into(),
+        name.into(),
+        None,
+        request.into(),
+        conn,
+        spec,
+        None,
+        None,
+    );
+    BareSession { session: Arc::new(session), events, _adapter: adapter }
+}

crates/ide-dap/src/kotlin.rs

@@ -9,6 +9,13 @@ use std::{
 
 pub const ADAPTER: &str = "kotlin-debug-adapter";
 
+/// The adapter attaches to a JVM the IDE starts, through the JDWP link. It resumes the VM while
+/// constructing its debuggee, before its breakpoint hooks exist, so the link holds resumes back
+/// until the attach is done.
+pub(crate) fn link_options() -> ide_jdwp::LinkOptions {
+    ide_jdwp::LinkOptions { hold_resumes: true }
+}
+
 pub struct SourceMirror {
     dir: tempfile::TempDir,
     paths: HashMap<PathBuf, PathBuf>,

crates/ide-dap/src/kotlin_jdwp.rs

@@ -1,166 +0,0 @@
-//! Keep a suspended JVM stopped until Kotlin's adapter has installed its listeners.
-//! The official 0.4.4 adapter resumes VMStart while constructing its debuggee, before
-//! installing breakpoint hooks. DAP attach completes only after those hooks exist.
-use ide_core::IdeResult;
-use std::{io, time::Duration};
-use tokio::{
-    io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt},
-    net::{TcpListener, TcpStream},
-    sync::oneshot,
-    task::JoinHandle,
-};
-
-pub(crate) struct StartupRelay {
-    release: Option<oneshot::Sender<()>>,
-    task: JoinHandle<()>,
-}
-
-impl StartupRelay {
-    pub async fn start(host: String, port: u16) -> IdeResult<(Self, u16)> {
-        let listener = TcpListener::bind(("127.0.0.1", 0)).await?;
-        let local = listener.local_addr()?.port();
-        let (release, ready) = oneshot::channel();
-        let task = tokio::spawn(async move {
-            let connect = async {
-                let (adapter, _) = listener.accept().await?;
-                let jvm = TcpStream::connect((host.as_str(), port)).await?;
-                adapter.set_nodelay(true)?;
-                jvm.set_nodelay(true)?;
-                Ok::<_, io::Error>((adapter, jvm))
-            };
-            if let Ok(Ok((adapter, jvm))) = tokio::time::timeout(Duration::from_secs(60), connect).await {
-                let (mut ar, mut aw) = adapter.into_split();
-                let (mut jr, mut jw) = jvm.into_split();
-                let upstream = forward(&mut ar, &mut jw, ready);
-                let downstream = tokio::io::copy(&mut jr, &mut aw);
-                // Close both sockets as soon as either side disconnects.
-                tokio::select! {
-                    r = upstream => if let Err(e) = r { tracing::debug!("Kotlin JDWP relay: {e}"); },
-                    _ = downstream => {},
-                }
-            }
-        });
-        Ok((Self { release: Some(release), task }, local))
-    }
-
-    pub fn release(&mut self) {
-        if let Some(ready) = self.release.take() {
-            let _ = ready.send(());
-        }
-    }
-}
-
-impl Drop for StartupRelay {
-    fn drop(&mut self) {
-        self.task.abort();
-    }
-}
-
-async fn packet(reader: &mut (impl AsyncRead + Unpin)) -> io::Result<Vec<u8>> {
-    let mut header = [0; 11];
-    reader.read_exact(&mut header).await?;
-    let len = u32::from_be_bytes(header[..4].try_into().unwrap()) as usize;
-    if !(11..=16 * 1024 * 1024).contains(&len) {
-        return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid JDWP packet length"));
-    }
-    let mut packet = vec![0; len];
-    packet[..11].copy_from_slice(&header);
-    reader.read_exact(&mut packet[11..]).await?;
-    Ok(packet)
-}
-
-async fn forward(
-    reader: &mut (impl AsyncRead + Unpin),
-    writer: &mut (impl AsyncWrite + Unpin),
-    mut ready: oneshot::Receiver<()>,
-) -> io::Result<()> {
-    let mut handshake = [0; 14];
-    reader.read_exact(&mut handshake).await?;
-    if &handshake != b"JDWP-Handshake" {
-        return Err(io::Error::new(io::ErrorKind::InvalidData, "Invalid JDWP handshake"));
-    }
-    writer.write_all(&handshake).await?;
-    let mut released = false;
-    let mut held: Vec<Vec<u8>> = Vec::new();
-    loop {
-        // Retain the in-flight read when attach completes, including partial packets.
-        let read = packet(reader);
-        tokio::pin!(read);
-        let packet = tokio::select! {
-            result = &mut read => result?,
-            result = &mut ready, if !released => {
-                result.map_err(|_| io::Error::new(io::ErrorKind::ConnectionAborted, "Kotlin attach cancelled"))?;
-                released = true;
-                for packet in held.drain(..) {
-                    writer.write_all(&packet).await?;
-                }
-                read.await?
-            }
-        };
-        // JDWP VirtualMachine.Resume (1/9), ThreadReference.Resume (11/3).
-        // Other commands must proceed: attach itself queries threads and installs requests.
-        if !released && packet[8] == 0 && matches!((packet[9], packet[10]), (1, 9) | (11, 3)) {
-            if held.len() >= 1024 {
-                return Err(io::Error::new(io::ErrorKind::InvalidData, "Too many pending JDWP resumes"));
-            }
-            held.push(packet);
-        } else {
-            writer.write_all(&packet).await?;
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    fn command(id: u8, set: u8, cmd: u8) -> Vec<u8> {
-        vec![0, 0, 0, 11, 0, 0, 0, id, 0, set, cmd]
-    }
-
-    #[tokio::test]
-    async fn holds_resumes_but_allows_setup_and_preserves_partial_reads() {
-        let (mut adapter, mut reader) = tokio::io::duplex(4096);
-        let (mut writer, mut jvm) = tokio::io::duplex(4096);
-        let (release, ready) = oneshot::channel();
-        let task = tokio::spawn(async move { forward(&mut reader, &mut writer, ready).await });
-        adapter.write_all(b"JDWP-Handshake").await.unwrap();
-        let mut handshake = [0; 14];
-        jvm.read_exact(&mut handshake).await.unwrap();
-        assert_eq!(&handshake, b"JDWP-Handshake");
-        let resume = command(1, 1, 9);
-        let thread_resume = command(2, 11, 3);
-        let setup = command(3, 1, 4);
-        adapter.write_all(&resume).await.unwrap();
-        adapter.write_all(&thread_resume).await.unwrap();
-        adapter.write_all(&setup).await.unwrap();
-        assert_eq!(packet(&mut jvm).await.unwrap(), setup);
-        let next = command(4, 1, 9);
-        adapter.write_all(&next[..6]).await.unwrap();
-        release.send(()).unwrap();
-        assert_eq!(packet(&mut jvm).await.unwrap(), resume);
-        assert_eq!(packet(&mut jvm).await.unwrap(), thread_resume);
-        adapter.write_all(&next[6..]).await.unwrap();
-        assert_eq!(packet(&mut jvm).await.unwrap(), next);
-        drop(adapter);
-        assert!(task.await.unwrap().is_err());
-    }
-
-    #[tokio::test]
-    async fn dropping_session_closes_relay() {
-        let (relay, port) = StartupRelay::start("127.0.0.1".into(), 1).await.unwrap();
-        let mut adapter = TcpStream::connect(("127.0.0.1", port)).await.unwrap();
-        drop(relay);
-        let result = tokio::time::timeout(Duration::from_secs(1), adapter.read_u8()).await.unwrap();
-        assert!(result.is_err());
-    }
-
-    #[tokio::test]
-    async fn rejects_invalid_packet_lengths() {
-        for len in [0_u32, 10, 16 * 1024 * 1024 + 1] {
-            let mut bytes = command(1, 1, 9);
-            bytes[..4].copy_from_slice(&len.to_be_bytes());
-            assert_eq!(packet(&mut bytes.as_slice()).await.unwrap_err().kind(), io::ErrorKind::InvalidData);
-        }
-    }
-}

crates/ide-dap/src/lib.rs

@@ -13,16 +13,16 @@ pub mod attach;
 mod cargo;
 pub mod connection;
 pub mod jdwp;
+mod jvm_memory;
 pub mod kotlin;
-mod kotlin_jdwp;
 mod session;
-pub mod target;
 
 use adapter::{AdapterLauncher, AdapterSpec, ProcessLauncher};
 use connection::{Connection, DapError};
 use futures::future::join_all;
 use ide_core::{DebugSessionId, IdeError, IdeResult, SharedSink};
 use ide_language::LanguageRegistry;
+pub use jvm_memory::*;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
 use serde_json::{Value, json};
@@ -127,6 +127,14 @@ pub struct DebugCapabilities {
     pub log_points: bool,
     /// HotSwap ("Reload Changed Classes"): java-debug's `redefineClasses` request.
     pub hot_code_replace: bool,
+    /// The session debugs a JVM, so it has a Memory view; [`DebugManager::jvm_memory_classes`]
+    /// says why when it has no data (platform, remote JVM, ...).
+    pub jvm_memory: bool,
+    /// The session has a JVM inspector: instances, fields and referrers while suspended. Can
+    /// change during the session ([`ide_core::event::DebugEvent::Capabilities`]).
+    pub jvm_instances: bool,
+    /// The session can be asked for a heap dump ([`DebugManager::jvm_heap_dump`]).
+    pub jvm_heap: bool,
 }
 
 /// Result of [`DebugManager::redefine_classes`].
@@ -303,6 +311,7 @@ pub struct DebugManager {
     data_breakpoints: Mutex<Vec<DataBreakpoint>>,
     /// In-flight stops, by session: a second Stop sets `stop_force`, the waiting one kills.
     stopping: Mutex<HashMap<DebugSessionId, Arc<Session>>>,
+    jvm_finder: Mutex<jvm_memory::JvmFinder>,
 }
 
 /// rdbg (Ruby's debug gem) starts the debuggee itself and ignores `launch`'s program,
@@ -567,9 +576,21 @@ pub(crate) fn capabilities_from(caps: &Value) -> DebugCapabilities {
         hit_conditional_breakpoints: has("supportsHitConditionalBreakpoints"),
         log_points: has("supportsLogPoints"),
         hot_code_replace: false,
+        jvm_memory: false,
+        jvm_instances: false,
+        jvm_heap: false,
     }
 }
 
+pub(crate) fn session_capabilities(session: &Session) -> DebugCapabilities {
+    let mut caps = capabilities_from(&session.caps.lock());
+    caps.hot_code_replace = HOT_CODE_REPLACE_ADAPTERS.contains(&session.adapter.as_str());
+    caps.jvm_memory = JVM_MEMORY_ADAPTERS.contains(&session.adapter.as_str());
+    caps.jvm_instances = session.jvm_inspector.lock().is_some();
+    caps.jvm_heap = JVM_MEMORY_ADAPTERS.contains(&session.adapter.as_str());
+    caps
+}
+
 /// States of a file's line breakpoints that no session has been sent.
 fn unsent(breakpoints: &[Breakpoint]) -> Vec<BreakpointState> {
     breakpoints
@@ -658,9 +679,15 @@ impl DebugManager {
             function_breakpoints: Mutex::default(),
             data_breakpoints: Mutex::default(),
             stopping: Mutex::default(),
+            jvm_finder: Mutex::new(Arc::new(jvm_memory::find_local_jvm)),
         })
     }
 
+    #[cfg(test)]
+    pub(crate) fn set_jvm_finder(&self, finder: jvm_memory::JvmFinder) {
+        *self.jvm_finder.lock() = finder;
+    }
+
     fn session(&self, s: DebugSessionId) -> IdeResult<Arc<Session>> {
         self.sessions.lock().get(&s).cloned().ok_or_else(|| no_session(s))
     }
@@ -697,17 +724,6 @@ impl DebugManager {
         config: LaunchConfig,
         owner: SessionOwner,
         custom_command: impl FnOnce(&str) -> Option<String>,
-    ) -> IdeResult<DebugSessionId> {
-        self.start_prepared(config, owner, custom_command, |_, _| Ok(())).await
-    }
-
-    /// Configure a target adapter before any host tool resolution or launch.
-    pub async fn start_prepared(
-        &self,
-        config: LaunchConfig,
-        owner: SessionOwner,
-        custom_command: impl FnOnce(&str) -> Option<String>,
-        prepare: impl FnOnce(&mut AdapterSpec, &mut Value) -> IdeResult<()>,
     ) -> IdeResult<DebugSessionId> {
         let mut arguments = launch_arguments(&config)?;
         // An IDE-side marker (never sent to the adapter): the session is a Flutter
@@ -722,22 +738,6 @@ impl DebugManager {
         let dbg = adapter::find_config(&self.languages, &config.adapter)
             .ok_or_else(|| IdeError::unavailable(format!("unknown debug adapter `{}`", config.adapter)))?;
         let mut spec = adapter::resolve(&dbg, cwd.clone());
-        prepare(&mut spec, &mut arguments)?;
-        if spec.target.is_some() {
-            return self
-                .start_session(
-                    DebugSessionId::next(),
-                    owner,
-                    config.name,
-                    config.adapter,
-                    None,
-                    config.request,
-                    arguments,
-                    spec,
-                    None,
-                )
-                .await;
-        }
         if config.adapter == kotlin::ADAPTER
             && let Some(home) = arguments
                 .as_object_mut()
@@ -746,6 +746,10 @@ impl DebugManager {
         {
             spec.env.push(("JAVA_HOME".into(), home));
         }
+        // Delve looks up Go before applying the debuggee's launch environment.
+        if config.adapter == "delve" {
+            spec.env.extend(config.env.iter().map(|(key, value)| (key.clone(), value.clone())));
+        }
         if config.adapter == "rdbg" {
             rdbg_command_line(&mut spec, &config, &cwd)?;
         }
@@ -778,6 +782,18 @@ impl DebugManager {
         if let Some(server) = &debug_server {
             spec.server_host = server.host.clone();
         }
+        if config.adapter == "gdb" && config.request == "launch" && debug_server.is_none() {
+            // GDB's DAP env replaces the entire inferior environment. Ordinary run overrides
+            // instead belong on the adapter process, which the inferior inherits. Explicit
+            // launch JSON keeps GDB's replacement semantics.
+            let explicit_env = config.extra_json.as_deref().is_some_and(|extra| {
+                serde_json::from_str::<Value>(extra).is_ok_and(|extra| extra.get("env").is_some())
+            });
+            if !explicit_env {
+                spec.env.extend(config.env.iter().map(|(k, v)| (k.clone(), v.clone())));
+                arguments.as_object_mut().unwrap().remove("env");
+            }
+        }
         if let Some(cargo) = arguments.as_object_mut().and_then(|o| o.remove("cargo")) {
             let cargo_args: Vec<String> = cargo
                 .get("args")
@@ -886,22 +902,12 @@ impl DebugManager {
         if request != "launch" && request != "attach" {
             return Err(IdeError::invalid(format!("request must be `launch` or `attach`, got `{request}`")));
         }
-        let io = self.launcher.launch(spec.clone(), reuse_port).await.map_err(|e| {
-            if spec.target.is_some() {
-                IdeError::new(e.kind, format!("{}\nargv: {:?} {:?}", e.message, spec.command, spec.args))
-            } else {
-                e
-            }
-        })?;
+        let io = self.launcher.launch(spec.clone(), reuse_port).await?;
+        let launch_after_configuration = io.launch_after_configuration && request == "launch";
         let stderr = io.stderr.clone();
         let (conn, incoming) = {
             let stderr = stderr.clone();
-            Connection::start_with_target(
-                io.reader,
-                io.writer,
-                Box::new(move |line| adapter::push_line(&stderr, line)),
-                spec.target.clone(),
-            )
+            Connection::start_with_output(io.reader, io.writer, Box::new(move |line| adapter::push_line(&stderr, line)))
         };
         let rdbg_pid = (adapter_name == "rdbg" && request == "launch")
             .then(|| io.child.as_ref().and_then(tokio::process::Child::id))
@@ -935,16 +941,13 @@ impl DebugManager {
         let configured = tokio::select! {
             biased;
             _ = session.startup_cancel.cancelled() => return Err(IdeError::cancelled()),
-            result = self.configure(&session, arguments) => result,
+            result = self.configure(&session, arguments, launch_after_configuration) => result,
         };
         match configured {
             Ok(()) => Ok(id),
             Err(e) => {
                 let e = if session.conn.is_closed() {
                     let mut msg = format!("debug adapter `{}` exited during startup", session.adapter);
-                    if session.spec.target.is_some() {
-                        msg.push_str(&format!("\nargv: {:?} {:?}", session.spec.command, session.spec.args));
-                    }
                     let tail = stderr.lock().join("\n");
                     if !tail.is_empty() {
                         msg.push_str(":\n");
@@ -955,17 +958,6 @@ impl DebugManager {
                         msg.push_str(hint);
                     }
                     IdeError::unavailable(msg)
-                } else if session.spec.target.is_some() {
-                    IdeError::new(
-                        e.kind,
-                        format!(
-                            "{}\nargv: {:?} {:?}\n{}",
-                            e.message,
-                            session.spec.command,
-                            session.spec.args,
-                            stderr.lock().join("\n")
-                        ),
-                    )
                 } else {
                     e
                 };
@@ -976,7 +968,7 @@ impl DebugManager {
         }
     }
 
-    async fn configure(&self, s: &Arc<Session>, mut arguments: Value) -> IdeResult<()> {
+    async fn configure(&self, s: &Arc<Session>, mut arguments: Value, launch_in_config: bool) -> IdeResult<()> {
         if s.adapter == kotlin::ADAPTER {
             let project = arguments
                 .get("projectRoot")
@@ -1003,8 +995,8 @@ impl DebugManager {
                     "pathFormat": "path",
                     "supportsVariableType": true,
                     "supportsVariablePaging": false,
-                    "supportsRunInTerminalRequest": s.spec.target.is_none(),
-                    "supportsStartDebuggingRequest": s.spec.target.is_none(),
+                    "supportsRunInTerminalRequest": true,
+                    "supportsStartDebuggingRequest": true,
                     "supportsProgressReporting": true,
                     "supportsInvalidatedEvent": false,
                     "supportsMemoryReferences": false,
@@ -1015,13 +1007,31 @@ impl DebugManager {
             .await?;
         *s.caps.lock() = if caps.is_object() { caps } else { json!({}) };
 
-        // The Kotlin adapter ignores the resolved classpath and project runtime on launch.
+        // The Kotlin adapters ignore the resolved classpath and project runtime on launch.
         let request = if s.adapter == kotlin::ADAPTER && s.request == "launch" {
             session::start_kotlin_debuggee(s, &mut arguments).await?;
             "attach"
         } else {
             &s.request
         };
+        // Both blocks below run before the Kotlin link replaces the JVM's address with its own.
+        if request == "attach"
+            && let Some(target) = jvm_memory::attach_target(&arguments)
+        {
+            let _ = s.attach_target.set(target);
+        }
+        if cfg!(unix)
+            && s.request == "attach"
+            && JVM_MEMORY_ADAPTERS.contains(&s.adapter.as_str())
+            && let Some(port) = jvm_memory::local_jdwp_port(&arguments)
+        {
+            if jdwp::is_listen_relay(port) {
+                s.listen_relay.store(true, Ordering::Release);
+            } else {
+                let finder = self.jvm_finder.lock().clone();
+                jvm_memory::find_attached_jvm(s, port, finder).await;
+            }
+        }
         if s.adapter == kotlin::ADAPTER {
             let host = arguments
                 .get("hostName")
@@ -1034,24 +1044,39 @@ impl DebugManager {
                 .and_then(|p| u16::try_from(p).ok())
                 .filter(|p| *p != 0)
                 .ok_or_else(|| IdeError::invalid("Invalid Kotlin JDWP port"))?;
-            let (relay, port) = kotlin_jdwp::StartupRelay::start(host, port).await?;
-            *s.kotlin_relay.lock() = Some(relay);
+            let (link, port) = ide_jdwp::JdwpLink::start(host, port, kotlin::link_options()).await?;
+            *s.jvm_inspector.lock() = Some(Arc::new(ide_jdwp::LinkInspector::new(link.clone())));
+            jvm_memory::watch_link(s, &link);
+            *s.jdwp_link.lock() = Some(link);
             arguments["hostName"] = json!("127.0.0.1");
             arguments["port"] = json!(port);
         }
+        s.jvm_located.send_replace(true);
         // Launch/attach may wait for a slow runtime or a remote target. Let the adapter report
         // failure; Stop cancels configuration and a closed connection fails the pending reply.
         // Many adapters answer only after `configurationDone`, so don't wait for the reply yet.
-        let launch = s.conn.send_request(request, arguments)?;
-        let mut launch = Box::pin(async move { launch.await.unwrap_or(Err(DapError::Closed)) });
+        // GDB 15 is the exception: its `launch` starts the program itself (14 runs at
+        // `configurationDone`, 16+ defers the launch there), so its launch waits below.
+        let mut launch = if launch_in_config {
+            None
+        } else {
+            let reply = s.conn.send_request(request, arguments.clone())?;
+            Some(Box::pin(async move { reply.await.unwrap_or(Err(DapError::Closed)) }))
+        };
         let mut initialized = s.initialized.subscribe();
         let mut launch_result = None;
-        let got_initialized = tokio::select! {
-            r = initialized.wait_for(|v| *v) => { r.map_err(|_| DapError::Closed)?; true }
-            r = &mut launch => {
-                r?;
-                launch_result = Some(());
-                false
+        let got_initialized = match launch.as_mut() {
+            Some(launch) => tokio::select! {
+                r = initialized.wait_for(|v| *v) => { r.map_err(|_| DapError::Closed)?; true }
+                r = launch => {
+                    r?;
+                    launch_result = Some(());
+                    false
+                }
+            },
+            None => {
+                initialized.wait_for(|v| *v).await.map_err(|_| DapError::Closed)?;
+                true
             }
         };
         if !got_initialized {
@@ -1109,11 +1134,20 @@ impl DebugManager {
             }
         }
         s.configured.store(true, Ordering::Release);
-        if launch_result.is_none() {
-            launch.await?;
+        match launch.as_mut() {
+            Some(launch) => {
+                if launch_result.is_none() {
+                    launch.await?;
+                }
+            }
+            None => {
+                // GDB 15: the breakpoints are in, so its `run` cannot miss them.
+                let reply = s.conn.send_request(request, arguments)?;
+                reply.await.unwrap_or(Err(DapError::Closed))?;
+            }
         }
-        if let Some(relay) = s.kotlin_relay.lock().as_mut() {
-            relay.release();
+        if let Some(link) = s.jdwp_link.lock().as_ref() {
+            link.release();
         }
         Ok(())
     }
@@ -1346,8 +1380,9 @@ impl DebugManager {
     }
 
     pub async fn threads(&self, s: DebugSessionId) -> IdeResult<Vec<ThreadInfo>> {
-        let body = self.session(s)?.conn.request_timeout("threads", Value::Null, REQUEST_TIMEOUT).await?;
-        Ok(body
+        let session = self.session(s)?;
+        let body = session.conn.request_timeout("threads", Value::Null, REQUEST_TIMEOUT).await?;
+        let threads: Vec<ThreadInfo> = body
             .get("threads")
             .and_then(Value::as_array)
             .map(|t| {
@@ -1358,7 +1393,8 @@ impl DebugManager {
                     })
                     .collect()
             })
-            .unwrap_or_default())
+            .unwrap_or_default();
+        Ok(threads)
     }
 
     pub async fn stack_trace(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<Vec<StackFrame>> {
@@ -1487,8 +1523,11 @@ impl DebugManager {
 
     pub async fn resume(&self, s: DebugSessionId, thread_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
+        let ticket = session.suspended.ticket();
         let body = session.conn.request_timeout("continue", json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await?;
+        // DAP: a response without the flag continued every thread.
         let all = body.get("allThreadsContinued").and_then(Value::as_bool).unwrap_or(true);
+        session.suspended.resumed(ticket, thread_id, all);
         session.emit(ide_core::event::DebugEvent::Continued { thread_id, all_threads_continued: all });
         Ok(())
     }
@@ -1528,7 +1567,10 @@ impl DebugManager {
             StepKind::Out => "stepOut",
         };
         let session = self.session(s)?;
+        let ticket = session.suspended.ticket();
         session.conn.request_timeout(command, json!({ "threadId": thread_id }), REQUEST_TIMEOUT).await?;
+        // A step runs its thread; other threads stopped by their own events stay stopped.
+        session.suspended.resumed(ticket, thread_id, false);
         session.emit(ide_core::event::DebugEvent::Continued { thread_id, all_threads_continued: true });
         Ok(())
     }
@@ -1626,10 +1668,12 @@ impl DebugManager {
     /// Step into a specific call of the current line (Smart Step Into).
     pub async fn step_in_target(&self, s: DebugSessionId, thread_id: i64, target_id: i64) -> IdeResult<()> {
         let session = self.session(s)?;
+        let ticket = session.suspended.ticket();
         session
             .conn
             .request_timeout("stepIn", json!({ "threadId": thread_id, "targetId": target_id }), REQUEST_TIMEOUT)
             .await?;
+        session.suspended.resumed(ticket, thread_id, false);
         session.emit(ide_core::event::DebugEvent::Continued { thread_id, all_threads_continued: true });
         Ok(())
     }
@@ -1663,10 +1707,68 @@ impl DebugManager {
     }
 
     pub fn capabilities(&self, s: DebugSessionId) -> IdeResult<DebugCapabilities> {
+        Ok(session_capabilities(&*self.session(s)?))
+    }
+
+    /// Class table of the session's JVM (`GC.class_histogram -all`, or counted by the debugger
+    /// while suspended where no histogram can be taken), with deltas against the session's
+    /// previous snapshot from the same source.
+    pub async fn jvm_memory_classes(&self, s: DebugSessionId) -> IdeResult<JvmMemoryResult> {
         let session = self.session(s)?;
-        let mut caps = capabilities_from(&session.caps.lock());
-        caps.hot_code_replace = HOT_CODE_REPLACE_ADAPTERS.contains(&session.adapter.as_str());
-        Ok(caps)
+        jvm_memory::session_classes(session).await
+    }
+
+    /// Writes a heap dump of the session's JVM to `dir/dump.hprof`, one class-table or dump
+    /// request per session at a time. Anything but `Ready` deletes `dir`, unless `s` is not a
+    /// session. On `cancel` the result is `Cancelled` at once, while a dump the JVM is writing
+    /// still holds the session's turn until the JVM answers.
+    pub async fn jvm_heap_dump(
+        &self,
+        s: DebugSessionId,
+        dir: PathBuf,
+        cancel: ide_core::CancellationToken,
+    ) -> IdeResult<JvmHeapOutcome> {
+        let session = self.session(s)?;
+        jvm_memory::session_heap_dump(session, dir, cancel).await
+    }
+
+    /// Gives the session the backend for [`Self::jvm_memory_instances`] and the debugger's class
+    /// counts; the UI is told to reload the session's capabilities.
+    pub fn set_jvm_inspector(
+        &self,
+        s: DebugSessionId,
+        inspector: Arc<dyn ide_jvm_inspect::JvmInspector>,
+    ) -> IdeResult<()> {
+        let session = self.session(s)?;
+        if session.ended.is_cancelled() {
+            return Err(no_session(s));
+        }
+        jvm_memory::set_inspector(&session, inspector);
+        Ok(())
+    }
+
+    /// Up to `limit` (clamped to `1..=MAX_INSTANCES`) instances of `class_name` while suspended.
+    pub async fn jvm_memory_instances(
+        &self,
+        s: DebugSessionId,
+        class_name: String,
+        limit: u32,
+    ) -> IdeResult<JvmInstancesResult> {
+        jvm_memory::instances(&*self.session(s)?, &class_name, limit).await
+    }
+
+    pub async fn jvm_memory_fields(&self, s: DebugSessionId, object: JvmObjectRef) -> IdeResult<JvmFieldsResult> {
+        jvm_memory::fields(&*self.session(s)?, object).await
+    }
+
+    /// Objects that point at `object`; `limit` 0 means `DEFAULT_REFERRERS`, at most `MAX_REFERRERS`.
+    pub async fn jvm_memory_referrers(
+        &self,
+        s: DebugSessionId,
+        object: JvmObjectRef,
+        limit: u32,
+    ) -> IdeResult<JvmReferrersResult> {
+        jvm_memory::referrers(&*self.session(s)?, object, limit).await
     }
 
     /// HotSwap: reloads the classes compiled since the session started (or since the

crates/ide-dap/src/session.rs

@@ -5,6 +5,8 @@ use crate::adapter::AdapterSpec;
 use crate::connection::{Connection, DapError, Incoming};
 use crate::{Breakpoint, BreakpointState, DataBreakpoint, DebugManager, FunctionBreakpoint, SessionOwner};
 use ide_core::event::DebugEvent;
+#[cfg(unix)]
+use ide_core::process::process_tree;
 use ide_core::{DebugSessionId, IdeEvent, TaskId};
 use parking_lot::Mutex;
 use serde_json::{Value, json};
@@ -62,6 +64,15 @@ pub(crate) struct Session {
     pub stop_force: AtomicBool,
     /// `systemProcessId` from the adapter's `process` event: the program being debugged.
     pub debuggee_pid: AtomicI64,
+    /// The JVM an app-launched (Kotlin) session started, or the local JVM an attach session
+    /// found by its JDWP port. Separate from `debuggee_pid`, which decides how Stop signals the
+    /// program and is 0 for Kotlin.
+    pub jvm_pid: AtomicI64,
+    /// JDWP port of an attach to a local JVM, to look the JVM up again; unset for a remote one.
+    pub jdwp_port: std::sync::OnceLock<u16>,
+    /// The attach goes through the listen-mode relay of [`crate::jdwp::listen_for_jvm`].
+    pub listen_relay: AtomicBool,
+    pub suspended: Suspension,
     /// Pids signalled for the current stop: the reported pid and everything it started (an
     /// adapter may report the launcher shell, whose child is the program).
     #[cfg_attr(not(unix), allow(dead_code))]
@@ -75,8 +86,105 @@ pub(crate) struct Session {
     /// Resolved path → the path as the IDE knows it, for adapters given resolved paths.
     resolved_paths: Mutex<HashMap<PathBuf, PathBuf>>,
     progress: Mutex<HashMap<String, TaskId>>,
-    pub kotlin_relay: Mutex<Option<crate::kotlin_jdwp::StartupRelay>>,
+    /// Relay between a Kotlin adapter and its JVM. Dropping it closes both sockets.
+    pub jdwp_link: parking_lot::Mutex<Option<ide_jdwp::JdwpLink>>,
+    pub jvm_inspector: parking_lot::Mutex<Option<Arc<dyn ide_jvm_inspect::JvmInspector>>>,
+    /// One inspector request per session at a time.
+    pub inspect_lock: tokio::sync::Mutex<()>,
+    /// Cancelled when the session ends, so a request still waiting on the inspector lets go of
+    /// it (and of the JDWP link it holds).
+    pub ended: ide_core::CancellationToken,
+    /// `hostName` (empty when absent) and `port` of the session's `attach` request, as the IDE
+    /// was given them: Kotlin then replaces them with the link's. Unlike `jdwp_port`, also set
+    /// for a remote JVM.
+    pub attach_target: std::sync::OnceLock<(String, u16)>,
+    /// Set once `configure` has recorded where the program's JVM is (the fields above, the
+    /// Kotlin link), just before the `launch`/`attach` request goes out.
+    pub jvm_located: watch::Sender<bool>,
     pub kotlin_mirror: Mutex<Option<crate::kotlin::SourceMirror>>,
+    pub jvm_memory: tokio::sync::Mutex<crate::JvmMemoryState>,
+}
+
+/// Which threads of the program are suspended: each from its `stopped` event until a
+/// `continued` event or a successful resume/step request for it. Never cleared elsewhere, since
+/// a stale "suspended" only makes a later check refuse. fwcd and java-debug stop a breakpoint's
+/// thread alone, so a thread can run while another stays stopped.
+///
+/// A resume reply ends only the stops taken before the request was sent: a thread's next
+/// `stopped` event can overtake the reply. The check and the removal happen under one lock, so
+/// no stop can land between them and be lost.
+#[derive(Default)]
+pub(crate) struct Suspension(Mutex<Stops>);
+
+#[derive(Default)]
+struct Stops {
+    /// Counts stops, and moves back to an earlier stopped thread: an object read under one
+    /// ticket is stale under another.
+    ticket: u64,
+    /// Threads stopped alone by their event, oldest first, with the ticket of that stop.
+    threads: Vec<(i64, u64)>,
+    /// The ticket of a stop of every thread (`allThreadsStopped`, or no thread id): any resume
+    /// ends it.
+    all: Option<u64>,
+}
+
+impl Stops {
+    fn latest(&self) -> Option<u64> {
+        self.threads.last().map(|&(_, ticket)| ticket).max(self.all)
+    }
+
+    /// Ends the stops taken by ticket `upto` of `thread`, or of every thread.
+    fn release(&mut self, thread: Option<i64>, every: bool, upto: u64) {
+        let latest = self.latest();
+        if every || thread.is_none() || self.all.is_some_and(|t| t <= upto) {
+            self.all = self.all.filter(|&t| t > upto);
+            self.threads.retain(|&(_, t)| t > upto);
+        } else {
+            self.threads.retain(|&(id, t)| Some(id) != thread || t > upto);
+        }
+        // Back on an earlier thread's stop, as the JDWP link moves to it with a new generation.
+        let now = self.latest();
+        if now.is_some() && now != latest {
+            self.ticket += 1;
+        }
+    }
+}
+
+impl Suspension {
+    /// Whether some thread is stopped.
+    pub fn get(&self) -> bool {
+        let stops = self.0.lock();
+        stops.all.is_some() || !stops.threads.is_empty()
+    }
+
+    /// A `stopped` event; `all`: its `allThreadsStopped`.
+    pub fn stopped(&self, thread: Option<i64>, all: bool) {
+        let mut stops = self.0.lock();
+        stops.ticket += 1;
+        let ticket = stops.ticket;
+        match thread.filter(|_| !all) {
+            Some(thread) => {
+                stops.threads.retain(|&(id, _)| id != thread);
+                stops.threads.push((thread, ticket));
+            }
+            None => stops.all = Some(ticket),
+        }
+    }
+
+    /// A `continued` event; `all`: its `allThreadsContinued`.
+    pub fn continued(&self, thread: Option<i64>, all: bool) {
+        self.0.lock().release(thread, all, u64::MAX);
+    }
+
+    /// Take before sending a resume-like request and pass to [`Self::resumed`].
+    pub fn ticket(&self) -> u64 {
+        self.0.lock().ticket
+    }
+
+    /// After a successful resume-like request for `thread`; `all`: every thread ran.
+    pub fn resumed(&self, ticket: u64, thread: i64, all: bool) {
+        self.0.lock().release(Some(thread), all, ticket);
+    }
 }
 
 /// Adapters that only match files by their resolved path: Godot maps a script to
@@ -125,6 +233,10 @@ impl Session {
             terminated: AtomicBool::new(false),
             stop_force: AtomicBool::new(false),
             debuggee_pid: AtomicI64::new(0),
+            jvm_pid: AtomicI64::new(0),
+            jdwp_port: std::sync::OnceLock::new(),
+            listen_relay: AtomicBool::new(false),
+            suspended: Suspension::default(),
             stop_pids: parking_lot::Mutex::new(Vec::new()),
             #[cfg(windows)]
             stop_tree: Mutex::new(None),
@@ -132,8 +244,14 @@ impl Session {
             breakpoint_ids: Mutex::new(HashMap::new()),
             resolved_paths: Mutex::new(HashMap::new()),
             progress: Mutex::new(HashMap::new()),
-            kotlin_relay: Mutex::new(None),
+            jdwp_link: parking_lot::Mutex::new(None),
+            jvm_inspector: parking_lot::Mutex::new(None),
+            inspect_lock: tokio::sync::Mutex::default(),
+            ended: ide_core::CancellationToken::new(),
+            attach_target: std::sync::OnceLock::new(),
+            jvm_located: watch::channel(false).0,
             kotlin_mirror: Mutex::new(None),
+            jvm_memory: tokio::sync::Mutex::default(),
         }
     }
 
@@ -294,7 +412,10 @@ impl Session {
 
     /// Kills the adapter and every debuggee we started.
     pub fn kill_processes(&self) {
-        self.kotlin_relay.lock().take();
+        self.ended.cancel();
+        // The inspector holds a clone of the link, so both go.
+        self.jvm_inspector.lock().take();
+        self.jdwp_link.lock().take();
         #[cfg(unix)]
         if self.request == "launch" {
             for group in launch_groups(self) {
@@ -351,32 +472,6 @@ pub(crate) async fn remember_debuggee(s: &Arc<Session>) {
     let _ = s;
 }
 
-/// The program and everything it started: an adapter may report the launcher shell, whose
-/// child is the debugged program, so stopping only the reported pid leaves the program alive.
-#[cfg(unix)]
-fn process_tree(pid: i32) -> Vec<i32> {
-    use std::collections::HashMap;
-    let Ok(out) = std::process::Command::new("ps").args(["-A", "-o", "pid=,ppid="]).output() else {
-        return vec![pid];
-    };
-    let mut children: HashMap<i32, Vec<i32>> = HashMap::new();
-    for line in String::from_utf8_lossy(&out.stdout).lines() {
-        let mut it = line.split_whitespace();
-        let (Some(p), Some(parent)) = (it.next(), it.next()) else { continue };
-        let (Ok(p), Ok(parent)) = (p.parse::<i32>(), parent.parse::<i32>()) else { continue };
-        children.entry(parent).or_default().push(p);
-    }
-    let mut tree = vec![pid];
-    let mut at = 0;
-    while at < tree.len() {
-        if let Some(kids) = children.get(&tree[at]) {
-            tree.extend(kids.iter().copied());
-        }
-        at += 1;
-    }
-    tree
-}
-
 /// Asks the program itself to exit (`force` = SIGKILL) without ending the adapter session:
 /// its output keeps flowing over DAP while it shuts down. The first call remembers the pid
 /// tree, because the reported pid may die before its program does.
@@ -600,18 +695,27 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
             s.emit(DebugEvent::Initialized);
         }
         "stopped" => {
+            let all = body.get("allThreadsStopped").and_then(Value::as_bool).unwrap_or(false);
+            s.suspended.stopped(int("threadId"), all);
+            let reason = str_("reason").unwrap_or_else(|| "pause".into());
             mgr.restore_breakpoints(s).await;
             s.emit(DebugEvent::Stopped {
                 thread_id: int("threadId").unwrap_or(0),
-                reason: str_("reason").unwrap_or_else(|| "pause".into()),
+                reason,
                 description: str_("description").or_else(|| str_("text")),
-                all_threads_stopped: body.get("allThreadsStopped").and_then(Value::as_bool).unwrap_or(false),
+                all_threads_stopped: all,
+            });
+        }
+        "continued" => {
+            let all = body.get("allThreadsContinued").and_then(Value::as_bool);
+            // DAP: an event without the flag continues its thread alone. The UI keeps treating
+            // it as all threads; the suspension, which holds only threads that stopped, need not.
+            s.suspended.continued(int("threadId"), all.unwrap_or(false));
+            s.emit(DebugEvent::Continued {
+                thread_id: int("threadId").unwrap_or(0),
+                all_threads_continued: all.unwrap_or(true),
             });
         }
-        "continued" => s.emit(DebugEvent::Continued {
-            thread_id: int("threadId").unwrap_or(0),
-            all_threads_continued: body.get("allThreadsContinued").and_then(Value::as_bool).unwrap_or(true),
-        }),
         "output" => {
             let category = str_("category").unwrap_or_else(|| "console".into());
             if category == "telemetry" {
@@ -700,10 +804,6 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
 }
 
 fn on_reverse_request(mgr: &Arc<DebugManager>, s: &Arc<Session>, seq: i64, command: &str, args: Value) {
-    if s.spec.target.is_some() {
-        let _ = s.conn.respond(seq, command, Err("This debugger does not support plugin run targets".into()));
-        return;
-    }
     match command {
         "runInTerminal" => {
             let result = run_in_terminal(s, &args);
@@ -921,6 +1021,19 @@ fn forward_output<R: AsyncRead + Unpin + Send + 'static>(s: &Session, mut stream
     });
 }
 
+/// The attach listener must be on the command line before the user's arguments, which may
+/// override it; the memory view needs it because the JVM is started by the IDE, not attached to.
+/// Not on Windows (`windows`), which the memory view does not support.
+fn kotlin_jvm_args(user: Vec<String>, windows: bool) -> Vec<String> {
+    if windows || !ide_jvm_attach::wants_listener_flag(&user.join(" ")) {
+        return user;
+    }
+    let mut args = Vec::with_capacity(user.len() + 1);
+    args.push(ide_jvm_attach::START_LISTENER_FLAG.to_owned());
+    args.extend(user);
+    args
+}
+
 /// Launch with the IDE's resolved runtime and classpath; the adapter only attaches.
 pub(crate) async fn start_kotlin_debuggee(s: &Arc<Session>, args: &mut Value) -> ide_core::IdeResult<()> {
     use tokio::io::{AsyncBufReadExt, BufReader};
@@ -935,7 +1048,7 @@ pub(crate) async fn start_kotlin_debuggee(s: &Arc<Session>, args: &mut Value) ->
         std::env::join_paths(strings("classPaths")).map_err(|e| ide_core::IdeError::invalid(e.to_string()))?;
     let mut cmd = tokio::process::Command::new(java);
     ide_core::process::prepare(cmd.as_std_mut());
-    cmd.args(strings("vmArguments"))
+    cmd.args(kotlin_jvm_args(strings("vmArguments"), cfg!(windows)))
         // Let the JVM pick its own port (`:0`) and report it below: pre-picking a free
         // port here races with other processes that may take it before the JVM binds.
         .arg("-agentlib:jdwp=transport=dt_socket,server=y,suspend=y,address=127.0.0.1:0")
@@ -969,11 +1082,12 @@ pub(crate) async fn start_kotlin_debuggee(s: &Arc<Session>, args: &mut Value) ->
     // forced stop), the session's job on Windows, so a stop reaches what it forks.
     ide_core::process::own_group(cmd.as_std_mut());
     let mut child = cmd.spawn()?;
-    #[cfg(windows)]
-    if let Some(pid) = child.id()
-        && let Some(job) = s.job.lock().as_ref()
-    {
-        job.assign_pid(pid);
+    if let Some(pid) = child.id() {
+        s.jvm_pid.store(i64::from(pid), Ordering::Release);
+        #[cfg(windows)]
+        if let Some(job) = s.job.lock().as_ref() {
+            job.assign_pid(pid);
+        }
     }
     if let Some(err) = child.stderr.take() {
         forward_output(s, err, "stderr");
@@ -1014,7 +1128,162 @@ fn parse_jdwp_port(line: &str) -> Option<u16> {
 
 #[cfg(test)]
 mod tests {
-    use super::parse_jdwp_port;
+    use super::{Suspension, kotlin_jvm_args, parse_jdwp_port};
+
+    #[test]
+    fn a_resume_reply_clears_the_stop_it_was_sent_for() {
+        let s = Suspension::default();
+        assert!(!s.get());
+        s.stopped(Some(1), true);
+        let ticket = s.ticket();
+        s.resumed(ticket, 1, true);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn a_stop_after_the_resume_request_keeps_the_session_suspended() {
+        let s = Suspension::default();
+        s.stopped(Some(1), true);
+        let ticket = s.ticket();
+        // The next breakpoint's `stopped` event overtakes the reply to `continue`.
+        s.continued(Some(1), true);
+        s.stopped(Some(1), true);
+        s.resumed(ticket, 1, true);
+        assert!(s.get());
+        // A reply for the new stop still clears it.
+        s.resumed(s.ticket(), 1, true);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn a_reply_after_a_continued_event_changes_nothing() {
+        let s = Suspension::default();
+        s.stopped(Some(1), true);
+        let ticket = s.ticket();
+        s.continued(Some(1), true);
+        s.resumed(ticket, 1, true);
+        assert!(!s.get());
+        s.stopped(Some(1), true);
+        assert!(s.get());
+    }
+
+    #[test]
+    fn concurrent_stops_are_never_lost() {
+        let s = std::sync::Arc::new(Suspension::default());
+        s.stopped(Some(1), true);
+        let ticket = s.ticket();
+        let stopping = {
+            let s = s.clone();
+            std::thread::spawn(move || (0..10_000).for_each(|_| s.stopped(Some(1), true)))
+        };
+        for _ in 0..10_000 {
+            s.resumed(ticket, 1, true);
+        }
+        stopping.join().unwrap();
+        // However they interleave, a resume for the old ticket never clears a later stop.
+        assert!(s.get());
+        assert_eq!(s.ticket(), ticket + 10_000);
+    }
+
+    /// fwcd and java-debug stop a breakpoint's thread alone (`SUSPEND_EVENT_THREAD`): 7, then 8.
+    fn two_threads_stopped() -> Suspension {
+        let s = Suspension::default();
+        s.stopped(Some(7), false);
+        s.stopped(Some(8), false);
+        s
+    }
+
+    #[test]
+    fn continuing_the_latest_stopped_thread_keeps_the_other_as_a_new_stop() {
+        let s = two_threads_stopped();
+        let ticket = s.ticket();
+        s.continued(Some(8), false);
+        assert!(s.get());
+        // Objects read on thread 8's stop are stale.
+        assert_eq!(s.ticket(), ticket + 1);
+        s.continued(Some(7), false);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn continuing_an_earlier_stopped_thread_keeps_the_latest_stop() {
+        let s = two_threads_stopped();
+        let ticket = s.ticket();
+        s.continued(Some(7), false);
+        assert!(s.get());
+        assert_eq!(s.ticket(), ticket);
+    }
+
+    #[test]
+    fn continuing_all_threads_ends_every_stop() {
+        let s = two_threads_stopped();
+        s.continued(Some(7), true);
+        assert!(!s.get());
+        let s = two_threads_stopped();
+        s.continued(None, false);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn continuing_a_thread_that_did_not_stop_changes_nothing() {
+        let s = two_threads_stopped();
+        let ticket = s.ticket();
+        s.continued(Some(5), false);
+        assert!(s.get());
+        assert_eq!(s.ticket(), ticket);
+    }
+
+    #[test]
+    fn a_step_reply_resumes_its_thread_alone() {
+        let s = two_threads_stopped();
+        let ticket = s.ticket();
+        s.resumed(ticket, 8, false);
+        assert!(s.get());
+        assert_eq!(s.ticket(), ticket + 1);
+        s.resumed(s.ticket(), 7, true);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn a_thread_stopping_again_before_its_resume_reply_stays_stopped() {
+        let s = two_threads_stopped();
+        let ticket = s.ticket();
+        // Thread 7's step ends, and its `stopped` event overtakes the reply to `next`.
+        s.stopped(Some(7), false);
+        s.resumed(ticket, 7, false);
+        s.continued(Some(8), false);
+        assert!(s.get());
+    }
+
+    #[test]
+    fn a_stop_of_every_thread_ends_with_any_resume() {
+        let s = Suspension::default();
+        s.stopped(Some(7), false);
+        s.stopped(Some(8), true);
+        s.continued(Some(8), false);
+        assert!(!s.get());
+        // A stop without a thread.
+        s.stopped(None, false);
+        s.resumed(s.ticket(), 5, false);
+        assert!(!s.get());
+    }
+
+    #[test]
+    fn kotlin_launch_starts_attach_listener_first() {
+        assert_eq!(
+            kotlin_jvm_args(vec!["-Xmx1g".into()], false),
+            vec!["-XX:+StartAttachListener".to_string(), "-Xmx1g".into()]
+        );
+        assert_eq!(
+            kotlin_jvm_args(vec!["-XX:+DisableAttachMechanism".into()], false),
+            vec!["-XX:+DisableAttachMechanism".to_string()]
+        );
+    }
+
+    #[test]
+    fn kotlin_launch_on_windows_gets_no_attach_listener() {
+        assert_eq!(kotlin_jvm_args(vec!["-Xmx1g".into()], true), vec!["-Xmx1g".to_string()]);
+    }
 
     #[test]
     fn reads_the_port_the_jvm_chose() {

crates/ide-dap/src/target.rs

@@ -1,72 +0,0 @@
-//! DAP path fields only: output, expressions, environment and program arguments are opaque.
-use ide_core::path_mapping::{Direction, PathMapping, file_path, file_uri};
-use serde_json::Value;
-
-#[derive(Clone, Debug)]
-pub struct TargetMapping {
-    pub paths: PathMapping,
-    pub external_prefix: String,
-}
-
-impl TargetMapping {
-    pub fn rewrite(&self, value: &mut Value, direction: Direction) {
-        match value {
-            Value::Array(items) => items.iter_mut().for_each(|v| self.rewrite(v, direction)),
-            Value::Object(fields) => {
-                for (key, value) in fields {
-                    if key == "pathMappings" {
-                        continue;
-                    }
-                    if matches!(key.as_str(), "path" | "program" | "cwd" | "localRoot" | "remoteRoot") {
-                        if let Some(path) = value.as_str() {
-                            if matches!(direction, Direction::ToTarget) && path.starts_with(&self.external_prefix) {
-                                if let Some(decoded) =
-                                    file_path(&format!("file:///{}", path.trim_start_matches(&self.external_prefix)))
-                                {
-                                    *value = decoded.into();
-                                }
-                            } else if let Some(mapped) = self.paths.map(path, direction) {
-                                *value = mapped.into();
-                            } else if matches!(direction, Direction::ToHost) && key == "path" && path.starts_with('/') {
-                                *value = format!(
-                                    "{}{}",
-                                    self.external_prefix,
-                                    file_uri(path).trim_start_matches("file:///")
-                                )
-                                .into();
-                            }
-                        }
-                    } else if !matches!(key.as_str(), "args" | "env" | "output" | "expression" | "value") {
-                        self.rewrite(value, direction);
-                    }
-                }
-            }
-            _ => {}
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use serde_json::json;
-    #[test]
-    fn maps_protocol_paths_without_changing_user_data_or_adapter_mappings() {
-        let m = TargetMapping {
-            paths: PathMapping::new("C:/project", "/app"),
-            external_prefix: "openidea-target://test/0/".into(),
-        };
-        let mut request = json!({"arguments":{"source":{"path":"C:/project/a.py"},"program":"C:/project/a.py","cwd":"C:/project", "args":["C:/project/text"],"env":{"path":"C:/project/text"},"pathMappings":[{"localRoot":"/app","remoteRoot":"/app"}]}});
-        m.rewrite(&mut request, Direction::ToTarget);
-        assert_eq!(request["arguments"]["source"]["path"], "/app/a.py");
-        assert_eq!(request["arguments"]["cwd"], "/app");
-        assert_eq!(request["arguments"]["args"][0], "C:/project/text");
-        assert_eq!(request["arguments"]["env"]["path"], "C:/project/text");
-        let mut response = json!({"body":{"stackFrames":[{"source":{"path":"/app/a.py"}},{"source":{"path":"/usr/lib/a.py"}}],"sources":[{"path":"/app/b.py"}],"output":"/app/a.py"}});
-        m.rewrite(&mut response, Direction::ToHost);
-        assert_eq!(response["body"]["stackFrames"][0]["source"]["path"], "C:\\project\\a.py");
-        assert_eq!(response["body"]["sources"][0]["path"], "C:\\project\\b.py");
-        assert_eq!(response["body"]["stackFrames"][1]["source"]["path"], "openidea-target://test/0/usr/lib/a.py");
-        assert_eq!(response["body"]["output"], "/app/a.py");
-    }
-}

crates/ide-dap/src/tests.rs

@@ -1,5 +1,7 @@
 //! Protocol flow against an in-memory fake adapter.
 
+mod jvm_inspect;
+
 use super::*;
 use crate::adapter::{AdapterIo, LaunchFuture};
 use ide_core::IdeEvent;
@@ -120,12 +122,24 @@ struct Script {
     supports_terminate: bool,
     /// Answer `setBreakpoints` only once this many are waiting (a client that waits for each never gets one).
     hold_set_breakpoints: usize,
+    /// Send a `continued` event right after the first `stopped` one.
+    continued_after_stop: bool,
+    /// Close the connection when a `pause` request arrives (the adapter dies).
+    hang_up_on_pause: bool,
+    /// Answer `continue` with this body and keep the program running, instead of letting it exit.
+    continue_reply: Option<Value>,
+    /// Answer `initialize` only after this long (a slow adapter keeps the session connecting).
+    delay_initialize: Option<Duration>,
     initialized_delay: Duration,
     launch_delay: Duration,
     /// Leave startup pending before `initialized` (false) or after configuration (true).
     pending_startup: Option<bool>,
     startup_error: Option<&'static str>,
     close_during_startup: bool,
+    /// GDB 15 semantics: `initialized` right after `initialize`, the program starts at
+    /// `launch`, and a `configurationDone` sent while it runs is refused with `notStopped`.
+    gdb15_starts_at_launch: bool,
+    launch_after_configuration: bool,
 }
 
 impl Default for Script {
@@ -140,11 +154,17 @@ impl Default for Script {
             output_after_terminate: false,
             supports_terminate: true,
             hold_set_breakpoints: 0,
+            continued_after_stop: false,
+            hang_up_on_pause: false,
+            continue_reply: None,
+            delay_initialize: None,
             initialized_delay: Duration::ZERO,
             launch_delay: Duration::ZERO,
             pending_startup: None,
             startup_error: None,
             close_during_startup: false,
+            gdb15_starts_at_launch: false,
+            launch_after_configuration: false,
         }
     }
 }
@@ -159,10 +179,12 @@ impl AdapterLauncher for FakeLauncher {
         let (client, server) = tokio::io::duplex(1 << 16);
         let log = self.log.clone();
         let script = self.script.clone();
+        let launch_after_configuration = script.launch_after_configuration;
         tokio::spawn(fake_adapter(server, log, script));
         let (r, w) = tokio::io::split(client);
         Box::pin(async move {
             Ok(AdapterIo {
+                launch_after_configuration,
                 reader: Box::new(r),
                 writer: Box::new(w),
                 child: None,
@@ -180,6 +202,7 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
     let mut seq = 1000;
     let mut pending_launch: Option<i64> = None;
     let mut held: Vec<Value> = Vec::new();
+    let mut running = false;
     macro_rules! send {
         ($v:expr) => {{
             let mut v: Value = $v;
@@ -200,24 +223,40 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
             continue;
         }
         match msg["command"].as_str().unwrap_or_default() {
-            "initialize" => ok!(
-                msg,
-                json!({
-                    "supportsConfigurationDoneRequest": true,
-                    "supportsCompletionsRequest": true,
-                    "supportsTerminateRequest": script.supports_terminate,
-                    "supportsSetVariable": true,
-                    "supportsFunctionBreakpoints": true,
-                    "supportsDataBreakpoints": true,
-                    "supportsStepInTargetsRequest": true,
-                    "supportsRestartFrame": true,
-                    "exceptionBreakpointFilters": [
-                        {"filter": "raised", "label": "Raised"},
-                        {"filter": "uncaught", "label": "Uncaught", "default": true, "description": "Uncaught exceptions"},
-                    ],
-                })
-            ),
+            "initialize" => {
+                if let Some(delay) = script.delay_initialize {
+                    tokio::time::sleep(delay).await;
+                }
+                ok!(
+                    msg,
+                    json!({
+                        "supportsConfigurationDoneRequest": true,
+                        "supportsCompletionsRequest": true,
+                        "supportsTerminateRequest": script.supports_terminate,
+                        "supportsSetVariable": true,
+                        "supportsFunctionBreakpoints": true,
+                        "supportsDataBreakpoints": true,
+                        "supportsStepInTargetsRequest": true,
+                        "supportsRestartFrame": true,
+                        "exceptionBreakpointFilters": [
+                            {"filter": "raised", "label": "Raised"},
+                            {"filter": "uncaught", "label": "Uncaught", "default": true, "description": "Uncaught exceptions"},
+                        ],
+                    })
+                );
+                if script.gdb15_starts_at_launch {
+                    // GDB 15 announces itself before it sees `launch` (which a client that
+                    // defers it sends late).
+                    send!(json!({"type": "event", "event": "initialized"}));
+                }
+            }
             "launch" | "attach" => {
+                if script.gdb15_starts_at_launch {
+                    // GDB 15 starts the program here and answers `launch` right away.
+                    running = true;
+                    ok!(msg, Value::Null);
+                    continue;
+                }
                 if script.close_during_startup {
                     return;
                 }
@@ -289,6 +328,14 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 ok!(msg, json!({"value": format!("{}!", msg["arguments"]["value"].as_str().unwrap()), "type": "int"}))
             }
             "configurationDone" => {
+                if script.gdb15_starts_at_launch && running {
+                    // GDB 15 answers `configurationDone` with `notStopped` while the program
+                    // it started at `launch` is still running.
+                    send!(
+                        json!({"type": "response", "request_seq": msg["seq"], "command": "configurationDone", "success": false, "message": "notStopped"})
+                    );
+                    continue;
+                }
                 if !script.ignore_configuration_done {
                     ok!(msg, Value::Null);
                 }
@@ -311,6 +358,9 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                 send!(
                     json!({"type": "event", "event": "stopped", "body": {"reason": "breakpoint", "threadId": 1, "allThreadsStopped": true}})
                 );
+                if script.continued_after_stop {
+                    send!(json!({"type": "event", "event": "continued", "body": {"threadId": 1}}));
+                }
                 send!(
                     json!({"type": "event", "event": "breakpoint", "body": {"reason": "changed", "breakpoint": {"id": 1, "verified": false, "message": "moved", "line": 9, "source": {"path": script.source_path}}}})
                 );
@@ -342,11 +392,13 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                     {"label": ""},
                 ]})
             ),
+            "continue" if script.continue_reply.is_some() => ok!(msg, script.continue_reply.clone().unwrap()),
             "continue" => {
                 ok!(msg, json!({"allThreadsContinued": true}));
                 send!(json!({"type": "event", "event": "exited", "body": {"exitCode": 3}}));
                 send!(json!({"type": "event", "event": "terminated"}));
             }
+            "pause" if script.hang_up_on_pause => break,
             "stepIn" | "stepOut" | "pause" => ok!(msg, Value::Null),
             "redefineClasses" => {
                 send!(
@@ -400,6 +452,8 @@ fn harness(script: Script) -> Harness {
         Arc::new(LanguageRegistry::from_configs(Vec::new())),
         Arc::new(FakeLauncher { log: log.clone(), script }),
     );
+    // A local attach must not send requests to the developer's own JVMs.
+    manager.set_jvm_finder(Arc::new(|_, _| None));
     Harness { manager, log, events, owner }
 }
 
@@ -510,6 +564,60 @@ async fn stop_cancels_pending_launch_and_attach() {
     }
 }
 
+/// GDB 15 must receive breakpoints and configurationDone before launch.
+#[tokio::test(start_paused = true)]
+async fn gdb_15_launch_waits_for_the_configuration() {
+    for deferred in [false, true] {
+        let h =
+            harness(Script { gdb15_starts_at_launch: true, launch_after_configuration: deferred, ..Script::default() });
+        let result = h.start(LaunchConfig { adapter: "gdb".into(), ..config() }).await;
+        if deferred {
+            let id = result.expect("GDB 15 defers its launch past the configuration");
+            let commands = h.commands();
+            let pos = |c: &str| commands.iter().position(|x| x == c).unwrap();
+            assert!(pos("launch") > pos("configurationDone"), "{commands:?}");
+            h.manager.stop(id).await.unwrap();
+        } else {
+            let error = result.unwrap_err();
+            assert!(error.message.contains("configurationDone failed: notStopped"), "{}", error.message);
+        }
+    }
+}
+
+#[tokio::test(start_paused = true)]
+async fn gdb_attach_keeps_the_normal_configuration_order() {
+    let h = harness(Script { launch_after_configuration: true, ..Script::default() });
+    let id = h.start(LaunchConfig { adapter: "gdb".into(), request: "attach".into(), ..config() }).await.unwrap();
+    let commands = h.commands();
+    let pos = |c: &str| commands.iter().position(|x| x == c).unwrap();
+    assert!(pos("attach") < pos("configurationDone"), "{commands:?}");
+    h.manager.stop(id).await.unwrap();
+}
+
+#[tokio::test(start_paused = true)]
+async fn gdb_run_environment_overrides_preserve_inheritance() {
+    for explicit in [None, Some(r#"{"env":{"ONLY":"explicit"}}"#)] {
+        let h = harness(Script::default());
+        let id = h
+            .start(LaunchConfig { adapter: "gdb".into(), extra_json: explicit.map(str::to_owned), ..config() })
+            .await
+            .unwrap();
+        let session = h.manager.session(id).unwrap();
+        {
+            let log = h.log.lock();
+            let args = &log.iter().find(|m| m["command"] == "launch").unwrap()["arguments"];
+            if explicit.is_some() {
+                assert_eq!(args["env"], json!({"ONLY": "explicit"}));
+                assert!(session.spec.env.is_empty());
+            } else {
+                assert!(args.get("env").is_none(), "GDB must inherit its process environment");
+                assert!(session.spec.env.contains(&("A".into(), "1".into())));
+            }
+        }
+        h.manager.stop(id).await.unwrap();
+    }
+}
+
 #[tokio::test(start_paused = true)]
 async fn startup_still_reports_adapter_failure_and_connection_closure() {
     for request in ["launch", "attach"] {
@@ -517,7 +625,6 @@ async fn startup_still_reports_adapter_failure_and_connection_closure() {
         let error = h.start(LaunchConfig { request: request.into(), ..config() }).await.unwrap_err();
         assert_eq!(error.message, format!("{request} failed: interpreter could not start"));
         assert!(h.manager.sessions(None).is_empty());
-
         let h = harness(Script { close_during_startup: true, ..Script::default() });
         let error = h.start(LaunchConfig { request: request.into(), ..config() }).await.unwrap_err();
         assert!(error.message.contains("debug adapter `debugpy` exited during startup"), "{error}");
@@ -1040,6 +1147,39 @@ async fn connects_to_running_debug_server_over_tcp() {
     assert!(events.lock().iter().any(|e| matches!(e, IdeEvent::Debug { event: DebugEvent::Started { .. }, .. })));
 }
 
+#[tokio::test]
+async fn delve_adapter_inherits_the_selected_go_environment() {
+    struct CaptureLauncher {
+        inner: FakeLauncher,
+        env: Arc<Mutex<Vec<(String, String)>>>,
+    }
+    impl AdapterLauncher for CaptureLauncher {
+        fn launch(&self, spec: AdapterSpec, reuse: Option<u16>) -> LaunchFuture {
+            *self.env.lock() = spec.env.clone();
+            self.inner.launch(spec, reuse)
+        }
+    }
+    let env = Arc::new(Mutex::new(Vec::new()));
+    let launcher =
+        CaptureLauncher { inner: FakeLauncher { log: Arc::default(), script: Script::default() }, env: env.clone() };
+    let manager = DebugManager::with_launcher(Arc::new(LanguageRegistry::from_configs(Vec::new())), Arc::new(launcher));
+    let (owner, _) = recording_owner("main");
+    let config = LaunchConfig {
+        name: "Go".into(),
+        adapter: "delve".into(),
+        request: "launch".into(),
+        program: Some("/project".into()),
+        args: vec![],
+        cwd: None,
+        env: BTreeMap::from([("PATH".into(), "/chosen/go/bin".into()), ("GOROOT".into(), "/chosen/go".into())]),
+        extra_json: Some(json!({"mode":"debug"}).to_string()),
+    };
+    let id = manager.start(config, owner).await.unwrap();
+    assert!(env.lock().contains(&("PATH".into(), "/chosen/go/bin".into())));
+    assert!(env.lock().contains(&("GOROOT".into(), "/chosen/go".into())));
+    manager.stop(id).await.unwrap();
+}
+
 /// Go Remote / Python remote: the adapter runs on another machine (`dlv --headless`,
 /// `debugpy --listen`); `debugServer: "host:port"` connects there instead of spawning one.
 #[tokio::test]
@@ -1236,6 +1376,36 @@ async fn hot_swap_only_for_java_debug() {
     assert_eq!(failed.error_message.as_deref(), Some("boom"));
 }
 
+/// A loopback port nothing listens on until `listen` is called on the socket, and that no parallel
+/// test can bind meanwhile. A port picked by binding to 0 and closing the listener can be taken
+/// by another test before the code under test connects to it.
+fn reserved_port() -> (tokio::net::TcpSocket, u16) {
+    // Without SO_REUSEADDR, which every `TcpListener::bind` sets: no other socket may bind it.
+    let socket = tokio::net::TcpSocket::new_v4().unwrap();
+    socket.bind(([127, 0, 0, 1], 0).into()).unwrap();
+    let port = socket.local_addr().unwrap().port();
+    (socket, port)
+}
+
+/// An editor that starts listening on the reserved port after `delay` and serves one session.
+#[cfg(unix)]
+fn fake_editor(socket: tokio::net::TcpSocket, delay: Duration, log: Log) {
+    tokio::spawn(async move {
+        tokio::time::sleep(delay).await;
+        let listener = socket.listen(1).unwrap();
+        let (stream, _) = listener.accept().await.unwrap();
+        // Closed once its session is accepted, so a later start finds no editor open.
+        drop(listener);
+        fake_adapter(stream, log, Script::default()).await;
+    });
+}
+
+#[tokio::test]
+async fn a_reserved_port_cannot_be_taken_by_a_parallel_test() {
+    let (_socket, port) = reserved_port();
+    assert!(tokio::net::TcpListener::bind(("127.0.0.1", port)).await.is_err(), "port {port} is still free to bind");
+}
+
 fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegistry> {
     let lang = ide_language::LanguageConfig {
         id: ide_core::LanguageId::new("gdscript"),
@@ -1253,7 +1423,6 @@ fn godot_registry(port: u16, command: &str, args: &[&str]) -> Arc<LanguageRegist
         tree_sitter: None,
         language_servers: vec![],
         debugger: Some(ide_language::DebuggerConfig {
-            target_placement: None,
             adapter: "godot".into(),
             command: command.into(),
             args: args.iter().map(|a| (*a).to_owned()).collect(),
@@ -1304,7 +1473,7 @@ async fn godot_connects_to_the_editor_adapter() {
 
 #[tokio::test]
 async fn godot_without_editor_or_executable_says_what_to_do() {
-    let port = std::net::TcpListener::bind(("127.0.0.1", 0)).unwrap().local_addr().unwrap().port();
+    let (_no_editor, port) = reserved_port();
     let (owner, _events) = recording_owner("main");
     let manager = DebugManager::new(godot_registry(port, "openidea-no-such-godot", &[]));
     let err = manager.start(godot_launch(&std::env::temp_dir()), owner).await.unwrap_err();
@@ -1317,15 +1486,9 @@ async fn godot_without_editor_or_executable_says_what_to_do() {
 #[cfg(unix)]
 #[tokio::test]
 async fn godot_starts_a_headless_editor_when_none_is_open() {
-    let port = std::net::TcpListener::bind(("127.0.0.1", 0)).unwrap().local_addr().unwrap().port();
+    let (editor, port) = reserved_port();
     let log: Log = Arc::default();
-    let server_log = log.clone();
-    tokio::spawn(async move {
-        tokio::time::sleep(std::time::Duration::from_millis(300)).await;
-        let listener = tokio::net::TcpListener::bind(("127.0.0.1", port)).await.unwrap();
-        let (stream, _) = listener.accept().await.unwrap();
-        fake_adapter(stream, server_log, Script::default()).await;
-    });
+    fake_editor(editor, Duration::from_millis(300), log.clone());
     let (owner, _events) = recording_owner("main");
     // `sleep` stands in for `godot --headless --editor --path ${root} …`.
     let manager = DebugManager::new(godot_registry(port, "sleep", &["30"]));
@@ -1528,7 +1691,7 @@ async fn a_plugin_language_runs_its_debug_adapter_from_the_approved_program() {
     std::fs::write(&program, "#!/bin/sh\nexec sleep 30\n").unwrap();
     std::fs::set_permissions(&program, std::fs::Permissions::from_mode(0o755)).unwrap();
 
-    let port = std::net::TcpListener::bind(("127.0.0.1", 0)).unwrap().local_addr().unwrap().port();
+    let (editor, port) = reserved_port();
     let mut gdscript = parse_definition(include_str!("../../../languages/gdscript.toml")).unwrap();
     let debugger = gdscript.debugger.as_mut().unwrap();
     debugger.args.clear();
@@ -1545,13 +1708,7 @@ async fn a_plugin_language_runs_its_debug_adapter_from_the_approved_program() {
     let _language = store.add("acme.godot".into(), gdscript);
 
     let log: Log = Arc::default();
-    let server_log = log.clone();
-    tokio::spawn(async move {
-        tokio::time::sleep(std::time::Duration::from_millis(300)).await;
-        let listener = tokio::net::TcpListener::bind(("127.0.0.1", port)).await.unwrap();
-        let (stream, _) = listener.accept().await.unwrap();
-        fake_adapter(stream, server_log, Script::default()).await;
-    });
+    fake_editor(editor, Duration::from_millis(300), log.clone());
     let (owner, _events) = recording_owner("main");
     let manager = DebugManager::new(registry.clone());
     let id = manager.start(godot_launch(&dir), owner).await.unwrap();
@@ -1903,6 +2060,418 @@ fn delve_leftovers_are_removed_without_touching_other_files() {
     std::fs::remove_dir_all(&dir).unwrap();
 }
 
+fn is_suspended(h: &Harness, id: DebugSessionId) -> bool {
+    h.manager.session(id).unwrap().suspended.get()
+}
+
+#[tokio::test]
+async fn stopped_event_marks_session_suspended() {
+    let h = harness(Script::default());
+    let id = h.start(config()).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    assert!(is_suspended(&h, id));
+}
+
+#[tokio::test]
+async fn resume_clears_suspended_without_continued_event() {
+    let h = harness(Script::default());
+    let id = h.start(config()).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    // The fake adapter ends the session after `continue`, so keep the session alive here.
+    let session = h.manager.session(id).unwrap();
+    assert!(session.suspended.get());
+    h.manager.resume(id, 1).await.unwrap();
+    assert!(!session.suspended.get());
+}
+
+/// After the fake adapter's stop of every thread ends, threads 7 then 8 stop alone, as a
+/// breakpoint does on fwcd and java-debug (`SUSPEND_EVENT_THREAD`).
+async fn threads_stopped(script: Script) -> (Harness, Arc<Session>, DebugSessionId) {
+    let h = harness(script);
+    let id = h.start(config()).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    let session = h.manager.session(id).unwrap();
+    session.suspended.continued(Some(1), true);
+    session.suspended.stopped(Some(7), false);
+    session.suspended.stopped(Some(8), false);
+    (h, session, id)
+}
+
+#[tokio::test]
+async fn resume_of_one_thread_keeps_the_others_suspended() {
+    let only_it = Script { continue_reply: Some(json!({"allThreadsContinued": false})), ..Script::default() };
+    let (h, session, id) = threads_stopped(only_it).await;
+    h.manager.resume(id, 7).await.unwrap();
+    assert!(session.suspended.get());
+    h.manager.resume(id, 8).await.unwrap();
+    assert!(!session.suspended.get());
+}
+
+#[tokio::test]
+async fn resume_reply_without_the_flag_continues_every_thread() {
+    let (h, session, id) = threads_stopped(Script { continue_reply: Some(json!({})), ..Script::default() }).await;
+    h.manager.resume(id, 7).await.unwrap();
+    assert!(!session.suspended.get());
+}
+
+#[tokio::test]
+async fn step_of_one_thread_keeps_the_others_suspended() {
+    let (h, session, id) = threads_stopped(Script::default()).await;
+    let ticket = session.suspended.ticket();
+    h.manager.step(id, 8, StepKind::Into).await.unwrap();
+    assert!(session.suspended.get());
+    // Thread 8 was the latest stop: what was read on it is stale.
+    assert_eq!(session.suspended.ticket(), ticket + 1);
+    h.manager.step_in_target(id, 7, 1).await.unwrap();
+    assert!(!session.suspended.get());
+}
+
+#[tokio::test]
+async fn continued_event_clears_suspended() {
+    let h = harness(Script { continued_after_stop: true, ..Script::default() });
+    let id = h.start(config()).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Continued { .. })).await;
+    assert!(!is_suspended(&h, id));
+}
+
+fn java_config(request: &str) -> LaunchConfig {
+    LaunchConfig { adapter: "java-debug".into(), request: request.into(), extra_json: None, ..config() }
+}
+
+fn remote_attach(adapter: &str, project: &std::path::Path) -> LaunchConfig {
+    LaunchConfig {
+        adapter: adapter.into(),
+        cwd: Some(project.to_owned().into()),
+        extra_json: Some(json!({"projectRoot": project, "hostName": "10.0.0.5", "port": 5005}).to_string()),
+        ..java_config("attach")
+    }
+}
+
+#[tokio::test]
+async fn attach_session_reports_capability() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    for adapter in ["java-debug", kotlin::ADAPTER] {
+        let id = h.start(remote_attach(adapter, project.path())).await.unwrap();
+        let caps = h.manager.capabilities(id).unwrap();
+        assert!(caps.jvm_memory, "{adapter}");
+        assert_eq!(caps.jvm_heap, caps.jvm_memory, "{adapter}");
+    }
+
+    let id = h.start(config()).await.unwrap();
+    let caps = h.manager.capabilities(id).unwrap();
+    assert!(!caps.jvm_memory);
+    assert_eq!(caps.jvm_heap, caps.jvm_memory);
+    assert_eq!(
+        h.manager.jvm_memory_classes(id).await.unwrap(),
+        JvmMemoryResult::Unavailable { reason: JvmMemoryUnavailable::NoJvmProcess, can_count_when_paused: false }
+    );
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn ended_attach_session_without_pid_reports_program_exited() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(remote_attach("java-debug", project.path())).await.unwrap();
+    h.manager.session(id).unwrap().terminated.store(true, Ordering::Release);
+    assert_eq!(
+        h.manager.jvm_memory_classes(id).await.unwrap(),
+        JvmMemoryResult::Unavailable { reason: JvmMemoryUnavailable::ProgramExited, can_count_when_paused: false }
+    );
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn listen_mode_attach_is_not_scanned() {
+    let h = harness(Script::default());
+    let scans = Arc::new(Mutex::new(Vec::new()));
+    let counted = scans.clone();
+    h.manager.set_jvm_finder(Arc::new(move |port, _| {
+        counted.lock().push(port);
+        None
+    }));
+    let (_jvm, relay) = jdwp::tests::connected_jvm().await;
+    let mut cfg = java_config("attach");
+    cfg.extra_json = Some(json!({"hostName": "127.0.0.1", "port": relay}).to_string());
+    let id = h.start(cfg).await.unwrap();
+    assert_eq!(
+        h.manager.jvm_memory_classes(id).await.unwrap(),
+        JvmMemoryResult::Unavailable {
+            reason: JvmMemoryUnavailable::ListenModeNotSupported,
+            can_count_when_paused: false
+        }
+    );
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    assert!(scans.lock().is_empty());
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn remote_host_is_not_scanned() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(remote_attach("java-debug", project.path())).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert_eq!(session.jdwp_port.get(), None);
+    assert_eq!(
+        h.manager.jvm_memory_classes(id).await.unwrap(),
+        JvmMemoryResult::Unavailable {
+            reason: JvmMemoryUnavailable::AttachedJvmNotFound,
+            can_count_when_paused: false
+        }
+    );
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 0);
+}
+
+/// The Memory view asks as soon as the session appears, while its JVM is still being looked up:
+/// answering then would claim there is no JVM to ask.
+#[cfg(unix)]
+#[tokio::test]
+async fn memory_asked_while_an_attach_connects_waits_for_its_jvm() {
+    let h = harness(Script { delay_initialize: Some(Duration::from_millis(300)), ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let (manager, owner) = (h.manager.clone(), h.owner.clone());
+    let config = remote_attach("java-debug", project.path());
+    let start = tokio::spawn(async move { manager.start(config, owner).await });
+    h.wait_event(|e| matches!(e, DebugEvent::Started { .. })).await;
+    let id = DebugSessionId(*event_sessions(&h.events).first().unwrap());
+    let session = h.manager.session(id).unwrap();
+    assert!(session.attach_target.get().is_none(), "asked too late to cover the connecting session");
+
+    h.manager.jvm_memory_classes(id).await.unwrap();
+    assert!(session.attach_target.get().is_some(), "answered before the attach was looked at");
+    start.await.unwrap().unwrap();
+}
+
+/// A JVM clears its JDWP listener address once a debugger connects, so only a scan made before
+/// the `attach` request can tell it by its port.
+#[cfg(unix)]
+#[tokio::test]
+async fn local_attach_finds_its_jvm_before_the_debugger_connects() {
+    let h = harness(Script::default());
+    let log = h.log.clone();
+    h.manager.set_jvm_finder(Arc::new(move |port, _| {
+        std::thread::sleep(Duration::from_millis(50));
+        let attached = log.lock().iter().any(|m| m["command"] == "attach");
+        (port == 5005 && !attached).then_some(4242)
+    }));
+    let mut cfg = java_config("attach");
+    cfg.extra_json = Some(json!({"hostName": "127.0.0.1", "port": 5005}).to_string());
+    let id = h.start(cfg).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 4242);
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn local_attach_remembers_its_jdwp_port() {
+    let h = harness(Script::default());
+    let ports = Arc::new(Mutex::new(Vec::new()));
+    let asked = ports.clone();
+    h.manager.set_jvm_finder(Arc::new(move |port, _| {
+        asked.lock().push(port);
+        Some(4242)
+    }));
+    let mut cfg = java_config("attach");
+    cfg.extra_json = Some(json!({"hostName": "localhost", "port": "5005"}).to_string());
+    let id = h.start(cfg).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert_eq!(session.jdwp_port.get(), Some(&5005));
+    assert_eq!(h.request("attach")["arguments"]["port"], "5005");
+    for _ in 0..200 {
+        if session.jvm_pid.load(Ordering::Acquire) != 0 {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 4242);
+    assert_eq!(ports.lock().first(), Some(&5005));
+}
+
+/// A fake `find_jvm_by_jdwp_port` for the JVM 4242, recording whether each scan ran while
+/// suspended. A JVM not `safe_while_suspended` (JDK below 17) is skipped by a suspended scan.
+#[cfg(unix)]
+fn counting_find(
+    safe_while_suspended: bool,
+) -> (Arc<Mutex<Vec<bool>>>, impl Fn(bool) -> Option<u32> + Clone + Send + 'static) {
+    let scans = Arc::new(Mutex::new(Vec::new()));
+    let counted = scans.clone();
+    (scans, move |suspended| {
+        counted.lock().push(suspended);
+        (!suspended || safe_while_suspended).then_some(4242)
+    })
+}
+
+#[cfg(unix)]
+async fn suspended_remote_attach(h: &Harness) -> Arc<Session> {
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(remote_attach("java-debug", project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    let session = h.manager.session(id).unwrap();
+    assert!(session.suspended.get());
+    session
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn background_scan_skips_an_old_jdk_while_suspended() {
+    let h = harness(Script::default());
+    let session = suspended_remote_attach(&h).await;
+    let (scans, find) = counting_find(false);
+    let task =
+        jvm_memory::watch_for_attached_jvm(&session, 5005, find, Duration::from_millis(5), Duration::from_secs(5));
+    tokio::time::sleep(Duration::from_millis(100)).await;
+    assert!(!scans.lock().is_empty() && scans.lock().iter().all(|&suspended| suspended));
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 0);
+
+    session.suspended.continued(None, true);
+    tokio::time::timeout(Duration::from_secs(2), task).await.unwrap().unwrap();
+    assert_eq!(scans.lock().last(), Some(&false));
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 4242);
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn background_scan_finds_a_jdk_17_or_later_while_suspended() {
+    let h = harness(Script::default());
+    let session = suspended_remote_attach(&h).await;
+    let (scans, find) = counting_find(true);
+    let task =
+        jvm_memory::watch_for_attached_jvm(&session, 5005, find, Duration::from_millis(5), Duration::from_secs(5));
+    tokio::time::timeout(Duration::from_secs(2), task).await.unwrap().unwrap();
+    assert_eq!(*scans.lock(), [true]);
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 4242);
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn background_scan_keeps_a_known_pid_and_stops_with_the_session() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(remote_attach("java-debug", project.path())).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    let session = h.manager.session(id).unwrap();
+    session.suspended.continued(None, true);
+    session.jvm_pid.store(7, Ordering::Release);
+    let watch = |find| {
+        jvm_memory::watch_for_attached_jvm(&session, 5005, find, Duration::from_millis(5), Duration::from_secs(5))
+    };
+    let (scans, find) = counting_find(true);
+    tokio::time::timeout(Duration::from_secs(2), watch(find)).await.unwrap().unwrap();
+    assert!(scans.lock().is_empty(), "a known pid needs no scan");
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 7);
+
+    // A refresh stores the pid while this scan is still running.
+    session.jvm_pid.store(0, Ordering::Release);
+    let racing = session.clone();
+    let find = move |_| {
+        racing.jvm_pid.store(7, Ordering::Release);
+        Some(4242)
+    };
+    let task =
+        jvm_memory::watch_for_attached_jvm(&session, 5005, find, Duration::from_millis(5), Duration::from_secs(5));
+    tokio::time::timeout(Duration::from_secs(2), task).await.unwrap().unwrap();
+    assert_eq!(session.jvm_pid.load(Ordering::Acquire), 7, "a pid stored first is kept");
+
+    h.manager.stop(id).await.unwrap();
+    let (scans, find) = counting_find(true);
+    tokio::time::timeout(Duration::from_secs(2), watch(find)).await.unwrap().unwrap();
+    assert!(scans.lock().is_empty());
+}
+
+#[cfg(unix)]
+#[tokio::test]
+async fn unknown_pid_reports_no_jvm_process() {
+    let h = harness(Script::default());
+    let id = h.start(java_config("launch")).await.unwrap();
+    assert!(h.manager.capabilities(id).unwrap().jvm_memory);
+    assert_eq!(
+        h.manager.jvm_memory_classes(id).await.unwrap(),
+        JvmMemoryResult::Unavailable { reason: JvmMemoryUnavailable::NoJvmProcess, can_count_when_paused: false }
+    );
+}
+
+fn kotlin_attach(project: &std::path::Path, host: &str, port: u16) -> LaunchConfig {
+    LaunchConfig {
+        adapter: kotlin::ADAPTER.into(),
+        cwd: Some(project.to_owned().into()),
+        extra_json: Some(json!({"projectRoot": project, "hostName": host, "port": port}).to_string()),
+        ..java_config("attach")
+    }
+}
+
+#[tokio::test]
+async fn kotlin_session_installs_link_inspector() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_attach(project.path(), "127.0.0.1", 5005)).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert!(session.jdwp_link.lock().is_some());
+    assert!(session.jvm_inspector.lock().is_some());
+}
+
+#[tokio::test]
+async fn attach_target_recorded_before_kotlin_rewrite() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_attach(project.path(), "10.0.0.5", 5005)).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert_eq!(session.attach_target.get(), Some(&("10.0.0.5".to_owned(), 5005)));
+    let sent = &h.request("attach")["arguments"];
+    assert_eq!(sent["hostName"], "127.0.0.1");
+    let link_port = sent["port"].as_u64().unwrap();
+    assert!(link_port != 0 && link_port != 5005);
+}
+
+#[tokio::test]
+async fn java_attach_records_target() {
+    let h = harness(Script::default());
+    let mut cfg = java_config("attach");
+    cfg.extra_json = Some(json!({"hostName": "localhost", "port": 5005}).to_string());
+    let id = h.start(cfg).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert_eq!(session.attach_target.get(), Some(&("localhost".to_owned(), 5005)));
+    assert!(session.jdwp_link.lock().is_none());
+    assert!(session.jvm_inspector.lock().is_none());
+}
+
+#[tokio::test]
+async fn attach_target_recorded_for_any_adapter() {
+    let h = harness(Script::default());
+    let mut cfg = java_config("attach");
+    // "x" is not a registered adapter; debugpy has no JVM link or memory support.
+    cfg.adapter = "debugpy".into();
+    cfg.extra_json = Some(json!({"hostName": "h", "port": 7}).to_string());
+    let id = h.start(cfg).await.unwrap();
+    assert_eq!(h.manager.session(id).unwrap().attach_target.get(), Some(&("h".to_owned(), 7)));
+}
+
+#[tokio::test]
+async fn launch_sessions_have_no_attach_target() {
+    let h = harness(Script::default());
+    let id = h.start(java_config("launch")).await.unwrap();
+    assert_eq!(h.manager.session(id).unwrap().attach_target.get(), None);
+}
+
+#[tokio::test]
+async fn closing_the_session_drops_the_link() {
+    let h = harness(Script { hang_up_on_pause: true, ..Script::default() });
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_attach(project.path(), "127.0.0.1", 5005)).await.unwrap();
+    let session = h.manager.session(id).unwrap();
+    assert!(session.jdwp_link.lock().is_some() && session.jvm_inspector.lock().is_some());
+    let _ = session.conn.request_timeout("pause", json!({"threadId": 1}), Duration::from_secs(2)).await;
+    for _ in 0..200 {
+        if h.manager.session(id).is_err() {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    assert!(session.jdwp_link.lock().is_none());
+    assert!(session.jvm_inspector.lock().is_none());
+}
+
 #[cfg(unix)]
 #[tokio::test]
 async fn rdbg_drains_test_output_after_dap_closes_before_killing_the_process() {
@@ -1929,6 +2498,7 @@ async fn rdbg_drains_test_output_after_dap_closes_before_killing_the_process() {
                 });
                 let (reader, writer) = tokio::io::split(client);
                 Ok(AdapterIo {
+                    launch_after_configuration: false,
                     reader: Box::new(reader),
                     writer: Box::new(writer),
                     child: Some(child),

crates/ide-dap/src/tests/jvm_inspect.rs

@@ -0,0 +1,401 @@
+//! Instances, fields and referrers through a session's JVM inspector.
+
+use super::*;
+use crate::jvm_memory::test_support::FakeInspector;
+use ide_core::event::JvmBackendState;
+use ide_jvm_inspect::{InspectError, JvmValue, VmTarget};
+use tokio::io::AsyncReadExt;
+
+fn debug_events(h: &Harness) -> Vec<DebugEvent> {
+    h.events
+        .lock()
+        .iter()
+        .filter_map(|e| match e {
+            IdeEvent::Debug { event, .. } => Some(event.clone()),
+            _ => None,
+        })
+        .collect()
+}
+
+fn backend_events(h: &Harness) -> Vec<JvmBackendState> {
+    debug_events(h)
+        .into_iter()
+        .filter_map(|e| match e {
+            DebugEvent::JvmBackend { state } => Some(state),
+            _ => None,
+        })
+        .collect()
+}
+
+/// A java-debug session stopped at its breakpoint, inspected by `fake`.
+async fn stopped_with(h: &Harness, config: LaunchConfig, fake: &Arc<FakeInspector>) -> DebugSessionId {
+    let id = h.start(config).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    h.manager.set_jvm_inspector(id, fake.clone()).unwrap();
+    id
+}
+
+fn object(id: u64) -> JvmValue {
+    JvmValue::Object { id, type_name: "A".into() }
+}
+
+const NOT_SUSPENDED: JvmInstancesResult =
+    JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::NotSuspended };
+
+#[tokio::test]
+async fn instances_need_a_suspended_session() {
+    let h = harness(Script { continued_after_stop: true, ..Script::default() });
+    let id = h.start(java_config("launch")).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Continued { .. })).await;
+    let fake = Arc::new(FakeInspector::default());
+    h.manager.set_jvm_inspector(id, fake.clone()).unwrap();
+    assert_eq!(h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap(), NOT_SUSPENDED);
+    assert_eq!(fake.calls(), 0);
+}
+
+#[tokio::test]
+async fn instances_without_an_inspector_have_no_backend() {
+    let h = harness(Script::default());
+    let id = h.start(java_config("launch")).await.unwrap();
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    assert_eq!(
+        h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::NoBackend }
+    );
+}
+
+#[tokio::test]
+async fn object_from_previous_stop_is_stale() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::default());
+    fake.instances.lock().push(object(7));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let JvmInstancesResult::Ready { generation, instances, truncated } =
+        h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap()
+    else {
+        panic!("instances unavailable");
+    };
+    assert_eq!((generation, instances, truncated), (1, vec![object(7)], false));
+
+    h.manager.session(id).unwrap().suspended.stopped(None, true);
+    let stale = JvmObjectRef { generation, id: 7 };
+    assert_eq!(
+        h.manager.jvm_memory_fields(id, stale).await.unwrap(),
+        JvmFieldsResult::Unavailable { reason: JvmInspectUnavailable::Stale }
+    );
+    assert_eq!(
+        h.manager.jvm_memory_referrers(id, stale, 10).await.unwrap(),
+        JvmReferrersResult::Unavailable { reason: JvmInspectUnavailable::Stale }
+    );
+    assert_eq!(fake.calls(), 1, "a stale object never reaches the inspector");
+    let current = JvmObjectRef { generation: 2, id: 7 };
+    assert_eq!(h.manager.jvm_memory_fields(id, current).await.unwrap(), JvmFieldsResult::Ready { fields: Vec::new() });
+}
+
+#[tokio::test]
+async fn instances_stay_readable_while_another_thread_is_stopped() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::default());
+    fake.instances.lock().push(object(7));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let session = h.manager.session(id).unwrap();
+    // Threads 20, 21, then 22 stop alone (SUSPEND_EVENT_THREAD).
+    session.suspended.continued(Some(1), true);
+    for thread in [20, 21, 22] {
+        session.suspended.stopped(Some(thread), false);
+    }
+    let instances = || h.manager.jvm_memory_instances(id, "A".into(), 10);
+    let result = instances().await.unwrap();
+    let JvmInstancesResult::Ready { generation, .. } = result else { panic!("{result:?}") };
+    let read_on_22 = JvmObjectRef { generation, id: 7 };
+
+    // An earlier thread resumes: the stop on 22 goes on, and so does what was read on it.
+    session.suspended.continued(Some(20), false);
+    assert_eq!(
+        h.manager.jvm_memory_fields(id, read_on_22).await.unwrap(),
+        JvmFieldsResult::Ready { fields: Vec::new() }
+    );
+
+    // The latest one resumes: 21 is still stopped, but what was read on 22 is stale.
+    session.suspended.continued(Some(22), false);
+    assert_eq!(
+        h.manager.jvm_memory_fields(id, read_on_22).await.unwrap(),
+        JvmFieldsResult::Unavailable { reason: JvmInspectUnavailable::Stale }
+    );
+    let result = instances().await.unwrap();
+    assert!(matches!(result, JvmInstancesResult::Ready { .. }), "{result:?}");
+}
+
+/// Starts `instances` on a held fake inspector; returns once the inspector was entered.
+async fn held_request(
+    h: &Harness,
+    id: DebugSessionId,
+    fake: &Arc<FakeInspector>,
+) -> tokio::task::JoinHandle<IdeResult<JvmInstancesResult>> {
+    let manager = h.manager.clone();
+    let request = tokio::spawn(async move { manager.jvm_memory_instances(id, "A".into(), 10).await });
+    tokio::time::timeout(Duration::from_secs(2), fake.entered.notified()).await.unwrap();
+    request
+}
+
+#[tokio::test]
+async fn stop_during_request_is_stale() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector { hold: true, ..FakeInspector::default() });
+    fake.instances.lock().push(object(7));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let request = held_request(&h, id, &fake).await;
+    h.manager.session(id).unwrap().suspended.stopped(None, true);
+    fake.release.notify_one();
+    assert_eq!(
+        request.await.unwrap().unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::Stale }
+    );
+}
+
+#[tokio::test]
+async fn resume_during_request_is_stale() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector { hold: true, ..FakeInspector::default() });
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let request = held_request(&h, id, &fake).await;
+    h.manager.session(id).unwrap().suspended.continued(None, true);
+    fake.release.notify_one();
+    assert_eq!(
+        request.await.unwrap().unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::Stale }
+    );
+}
+
+#[tokio::test]
+async fn one_request_at_a_time_per_session() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector { hold: true, ..FakeInspector::default() });
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let first = held_request(&h, id, &fake).await;
+    let manager = h.manager.clone();
+    let second = tokio::spawn(async move { manager.jvm_memory_instances(id, "B".into(), 10).await });
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    assert_eq!(fake.calls(), 1, "the second request waits for the first");
+    fake.release.notify_one();
+    first.await.unwrap().unwrap();
+    tokio::time::timeout(Duration::from_secs(2), fake.entered.notified()).await.unwrap();
+    fake.release.notify_one();
+    second.await.unwrap().unwrap();
+    assert_eq!(fake.calls(), 2);
+}
+
+#[tokio::test]
+async fn session_end_lets_go_of_a_waiting_inspector() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector { hold: true, ..FakeInspector::default() });
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let request = held_request(&h, id, &fake).await;
+    h.manager.session(id).unwrap().kill_processes();
+    assert_eq!(
+        tokio::time::timeout(Duration::from_secs(2), request).await.unwrap().unwrap().unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::BackendClosed }
+    );
+    assert_eq!(Arc::strong_count(&fake), 1, "no clone of the inspector outlives the session");
+}
+
+#[tokio::test]
+async fn target_carries_pid_for_launch() {
+    let h = harness(Script { debuggee_pid: Some(4242), java_process_id: true, ..Script::default() });
+    let fake = Arc::new(FakeInspector::default());
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap();
+    assert_eq!(
+        *fake.targets.lock(),
+        [VmTarget { pid: Some(4242), attach_host: None, attach_port: None, generation: 1 }]
+    );
+}
+
+#[tokio::test]
+async fn target_carries_attach_port_and_host() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let fake = Arc::new(FakeInspector::default());
+    let id = stopped_with(&h, remote_attach("java-debug", project.path()), &fake).await;
+    h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap();
+    assert_eq!(
+        *fake.targets.lock(),
+        [VmTarget { pid: None, attach_host: Some("10.0.0.5".into()), attach_port: Some(5005), generation: 1 }]
+    );
+}
+
+#[tokio::test]
+async fn unsupported_backend_turns_instances_off() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::failing(InspectError::Unsupported("x".into())));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let before = debug_events(&h).len();
+    assert_eq!(
+        h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::Unsupported { detail: "x".into() } }
+    );
+    let after: Vec<_> = debug_events(&h).split_off(before);
+    assert!(
+        matches!(
+            after.as_slice(),
+            [DebugEvent::JvmBackend { state: JvmBackendState::Unsupported { detail } }, DebugEvent::Capabilities]
+                if detail == "x"
+        ),
+        "{after:?}"
+    );
+    assert!(!h.manager.capabilities(id).unwrap().jvm_instances);
+    assert_eq!(
+        h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap(),
+        JvmInstancesResult::Unavailable { reason: JvmInspectUnavailable::NoBackend }
+    );
+    assert_eq!(fake.calls(), 1);
+}
+
+/// `error` is reported but leaves the backend on.
+async fn keeps_the_backend(error: InspectError, reason: JvmInspectUnavailable) {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::failing(error));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let object = JvmObjectRef { generation: 1, id: 7 };
+    assert_eq!(h.manager.jvm_memory_fields(id, object).await.unwrap(), JvmFieldsResult::Unavailable { reason });
+    assert!(h.manager.capabilities(id).unwrap().jvm_instances);
+    assert!(backend_events(&h).is_empty());
+    assert!(h.manager.session(id).unwrap().jvm_inspector.lock().is_some());
+}
+
+#[tokio::test]
+async fn collected_keeps_the_backend() {
+    keeps_the_backend(InspectError::Collected, JvmInspectUnavailable::Collected).await;
+}
+
+#[tokio::test]
+async fn timed_out_keeps_the_backend() {
+    keeps_the_backend(InspectError::TimedOut, JvmInspectUnavailable::TimedOut).await;
+}
+
+#[tokio::test]
+async fn failed_inspection_is_an_error() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::failing(InspectError::Failed("boom".into())));
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let err = h.manager.jvm_memory_instances(id, "A".into(), 10).await.unwrap_err();
+    assert!(err.to_string().contains("boom"), "{err}");
+    assert!(h.manager.capabilities(id).unwrap().jvm_instances);
+}
+
+#[tokio::test]
+async fn limits_are_clamped() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::default());
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    for limit in [5000, 0] {
+        h.manager.jvm_memory_instances(id, "A".into(), limit).await.unwrap();
+    }
+    let object = JvmObjectRef { generation: 1, id: 7 };
+    for limit in [0, 900, 20] {
+        h.manager.jvm_memory_referrers(id, object, limit).await.unwrap();
+    }
+    assert_eq!(*fake.limits.lock(), [1000, 1, 50, 200, 20]);
+}
+
+#[tokio::test]
+async fn a_full_page_is_truncated() {
+    let h = harness(Script::default());
+    let fake = Arc::new(FakeInspector::default());
+    fake.instances.lock().extend([object(1), object(2)]);
+    let id = stopped_with(&h, java_config("launch"), &fake).await;
+    let truncated = |r: JvmInstancesResult| match r {
+        JvmInstancesResult::Ready { truncated, .. } => truncated,
+        other => panic!("{other:?}"),
+    };
+    assert!(truncated(h.manager.jvm_memory_instances(id, "A".into(), 2).await.unwrap()));
+    assert!(!truncated(h.manager.jvm_memory_instances(id, "A".into(), 3).await.unwrap()));
+}
+
+#[tokio::test]
+async fn capability_follows_the_inspector() {
+    let h = harness(Script::default());
+    let id = h.start(java_config("launch")).await.unwrap();
+    assert!(!h.manager.capabilities(id).unwrap().jvm_instances);
+    let before = debug_events(&h).len();
+    h.manager.set_jvm_inspector(id, Arc::new(FakeInspector::default())).unwrap();
+    assert!(h.manager.capabilities(id).unwrap().jvm_instances);
+    assert!(matches!(debug_events(&h).split_off(before).as_slice(), [DebugEvent::Capabilities]));
+}
+
+#[tokio::test]
+async fn remote_attach_counts_classes_through_the_debugger() {
+    let h = harness(Script::default());
+    let project = tempfile::tempdir().unwrap();
+    let fake = Arc::new(FakeInspector::default());
+    fake.counts.lock().push(ide_jvm_inspect::ClassCount { name: "A".into(), instances: 3 });
+    let id = stopped_with(&h, remote_attach("java-debug", project.path()), &fake).await;
+    let result = h.manager.jvm_memory_classes(id).await.unwrap();
+    assert!(
+        matches!(&result, JvmMemoryResult::Ready { snapshot }
+            if snapshot.source == JvmMemorySource::Debugger && snapshot.rows.len() == 1),
+        "{result:?}"
+    );
+    assert_eq!(fake.targets.lock()[0].attach_port, Some(5005));
+}
+
+const HANDSHAKE: &[u8; 14] = b"JDWP-Handshake";
+
+/// A Kotlin attach whose link reaches a fake JVM: (adapter end, JVM end) after both handshakes.
+async fn linked_kotlin(h: &Harness) -> (DebugSessionId, tokio::net::TcpStream, tokio::net::TcpStream) {
+    let jvm = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let project = tempfile::tempdir().unwrap();
+    let id = h.start(kotlin_attach(project.path(), "127.0.0.1", jvm.local_addr().unwrap().port())).await.unwrap();
+    let link_port = h.request("attach")["arguments"]["port"].as_u64().unwrap() as u16;
+    let mut adapter = tokio::net::TcpStream::connect(("127.0.0.1", link_port)).await.unwrap();
+    adapter.write_all(HANDSHAKE).await.unwrap();
+    let (mut jvm, _) = tokio::time::timeout(Duration::from_secs(2), jvm.accept()).await.unwrap().unwrap();
+    let mut buf = [0; 14];
+    jvm.read_exact(&mut buf).await.unwrap();
+    jvm.write_all(HANDSHAKE).await.unwrap();
+    adapter.read_exact(&mut buf).await.unwrap();
+    (id, adapter, jvm)
+}
+
+/// A command the adapter sends with an id from the link's own range: the link then only forwards.
+async fn degrade(adapter: &mut tokio::net::TcpStream) {
+    let mut packet = 11u32.to_be_bytes().to_vec();
+    packet.extend(ide_jdwp::OWN_IDS.start.to_be_bytes());
+    packet.extend([0, 1, 1]);
+    adapter.write_all(&packet).await.unwrap();
+}
+
+async fn wait_backend(h: &Harness, want: impl Fn(&JvmBackendState) -> bool) {
+    h.wait_event(|e| matches!(e, DebugEvent::JvmBackend { state } if want(state))).await;
+}
+
+#[tokio::test]
+async fn kotlin_link_reports_degraded_then_closed() {
+    let h = harness(Script::default());
+    let (id, mut adapter, jvm) = linked_kotlin(&h).await;
+    degrade(&mut adapter).await;
+    wait_backend(&h, |s| matches!(s, JvmBackendState::Degraded { .. })).await;
+    drop(jvm);
+    wait_backend(&h, |s| *s == JvmBackendState::Closed).await;
+    assert_eq!(backend_events(&h).len(), 2, "{:?}", backend_events(&h));
+    let session = h.manager.session(id).unwrap();
+    assert!(session.jdwp_link.lock().is_some(), "a closed link is kept until the session ends");
+}
+
+#[tokio::test]
+async fn kotlin_link_is_quiet_once_the_program_ended() {
+    let h = harness(Script::default());
+    let (id, _adapter, jvm) = linked_kotlin(&h).await;
+    let session = h.manager.session(id).unwrap();
+    // The adapter reported the end; the session keeps its link until it shuts down.
+    session.terminated.store(true, Ordering::Release);
+    drop(jvm);
+    for _ in 0..100 {
+        if session.jdwp_link.lock().as_ref().is_some_and(|l| l.state() == ide_jdwp::LinkState::Closed) {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    assert!(backend_events(&h).is_empty(), "{:?}", backend_events(&h));
+}

crates/ide-dap/tests/fixtures/target_adapter.py

@@ -1,30 +0,0 @@
-import sys,json,os,socket
-root=os.environ.get("FAKE_ROOT","/app")
-r=sys.stdin.buffer; w=sys.stdout.buffer
-seq=0
-def send(v):
- global seq
- seq+=1; v['seq']=seq
- b=json.dumps(v).encode(); w.write(('Content-Length: %d\r\n\r\n'%len(b)).encode()+b); w.flush()
-while True:
- line=r.readline()
- if not line: break
- n=int(line.split(b':')[1]); assert r.readline()==b'\r\n'
- q=json.loads(r.read(n)); c=q['command']; a=q.get('arguments',{}); body={}
- if c=='initialize': body={'supportsConfigurationDoneRequest':True}
- if c=='launch':
-  if 'program' in a: assert a['program']==root+'/main.py',a
-  if os.environ.get('FAKE_CONNECT_BACK'):
-   listener=socket.socket(); listener.bind(('127.0.0.1',a['port'])); listener.listen()
-  assert a['cwd']==root,a
-  send({'type':'event','event':'initialized'})
- if c=='setBreakpoints':
-  assert a['source']['path']==root+'/main.py',a
-  body={'breakpoints':[{'verified':True,'line':3}]}
- if c=='threads': body={'threads':[{'id':1,'name':'target main'}]}
- if c=='configurationDone': send({'type':'event','event':'stopped','body':{'reason':'breakpoint','threadId':1,'allThreadsStopped':True}})
- if c=='stackTrace' and os.environ.get('FAKE_CONNECT_BACK'):
-  client,_=listener.accept(); assert client.recv(4096).decode()==root+'/main.py'; client.close()
- if c=='stackTrace': body={'stackFrames':[{'id':1,'name':'main','line':3,'column':1,'source':{'path':root+'/main.py'}}]}
- send({'type':'response','request_seq':q['seq'],'command':c,'success':True,'body':body})
- if c=='disconnect': break

crates/ide-dap/tests/php_debug.rs

@@ -93,23 +93,9 @@ async fn listens_for_xdebug_until_stopped_with_path_mappings() {
         .await
         .unwrap();
     let id = manager
-        .start_prepared(
-            listen_config(port, &served, &served),
-            SessionOwner::new("main", sink.clone()),
-            |_| None,
-            |spec, _| {
-                spec.command = adapter.clone();
-                spec.cwd = local.clone();
-                spec.target = Some(ide_dap::target::TargetMapping {
-                    paths: ide_core::path_mapping::PathMapping::new(
-                        &local.to_string_lossy(),
-                        &served.to_string_lossy(),
-                    ),
-                    external_prefix: "openidea-target://php/0/".into(),
-                });
-                Ok(())
-            },
-        )
+        .start_with(listen_config(port, &served, &local), SessionOwner::new("main", sink.clone()), |_| {
+            Some(adapter.clone())
+        })
         .await
         .unwrap_or_else(|e| panic!("start: {e:?}"));
 

crates/ide-dap/tests/real_adapters.rs

@@ -151,6 +151,16 @@ fn cases(dir: &Path) -> Vec<Case> {
             field: None,
             config: launch("lldb-dap", &c.join("main"), &c, serde_json::json!({"env": ["OPENIDEA_FIXTURE=1"]})),
         },
+        // GDB's own DAP interpreter needs GDB 14+; older ones are skipped by `installed`.
+        Case {
+            adapter: "gdb",
+            source: c.join("main.c"),
+            loop_line: 13,
+            after_loop: 15,
+            function: "parse",
+            field: None,
+            config: launch("gdb", &c.join("main"), &c, serde_json::json!({})),
+        },
     ]);
     out
 }
@@ -230,6 +240,16 @@ fn installed(adapter: &str) -> bool {
         "js-debug" => "js-debug-adapter",
         "delve" => "dlv",
         "java-debug" => return true,
+        // Only a GDB with the DAP interpreter (14+) counts as installed.
+        "gdb" => {
+            return std::process::Command::new("gdb").arg("--version").output().is_ok_and(|out| {
+                String::from_utf8_lossy(&out.stdout)
+                    .lines()
+                    .next()
+                    .and_then(adapter::parse_gdb_version)
+                    .is_some_and(|(major, _)| major >= 14)
+            });
+        }
         other => other,
     };
     adapter::resolve_binary(cmd, Path::new("/")).is_some()

crates/ide-dap/tests/target_debug.rs

@@ -1,130 +0,0 @@
-//! Real stdio transport through a target wrapper, without Docker or installed adapters.
-#![cfg(unix)]
-use ide_core::{SharedSink, path_mapping::PathMapping};
-use ide_dap::{target::TargetMapping, *};
-use ide_language::LanguageRegistry;
-use std::{collections::BTreeMap, sync::Arc};
-
-const ADAPTER: &str = include_str!("fixtures/target_adapter.py");
-
-#[tokio::test]
-async fn stdio_adapter_through_target_maps_launch_breakpoints_and_frames() {
-    use std::os::unix::fs::PermissionsExt;
-    let tmp = tempfile::tempdir().unwrap();
-    let root = tmp.path().canonicalize().unwrap();
-    let adapter = root.join("adapter.py");
-    std::fs::write(&adapter, ADAPTER).unwrap();
-    let wrapper = root.join("wrapper");
-    std::fs::write(&wrapper, "#!/bin/sh\nprintf '%s\\n' \"$@\" > wrapper-argv\nexec \"$@\"\n").unwrap();
-    std::fs::set_permissions(&wrapper, std::fs::Permissions::from_mode(0o755)).unwrap();
-    let target = ide_core::remote_settings::PluginRunTarget {
-        id: "fake".into(),
-        name: "Fake".into(),
-        program: "wrapper".into(),
-        args: vec![],
-        workdir_args: vec![],
-        container_root: Some("/app".into()),
-        commands: vec![],
-    };
-    // Keep the fixture adapter outside mapped argv; this is the container's executable.
-    let run: ide_run::RunConfig = serde_json::from_value(serde_json::json!({"id":"adapter","name":"Adapter","kind":"shell","command":"/usr/bin/python3","args":["-u","-c",ADAPTER],"cwd":".","env":{},"detected":false,"isTest":false})).unwrap();
-    let run = ide_remote::plugin_target::prepare(&root, &target, &wrapper, &run).unwrap();
-    let manager = DebugManager::new(Arc::new(LanguageRegistry::load(None).unwrap()));
-    manager
-        .set_breakpoints(
-            root.join("main.py"),
-            vec![Breakpoint { line: 2, enabled: true, condition: None, hit_condition: None, log_message: None }],
-        )
-        .await
-        .unwrap();
-    let config = LaunchConfig {
-        name: "Target".into(),
-        adapter: "debugpy".into(),
-        request: "launch".into(),
-        program: Some(root.join("main.py").to_string_lossy().into_owned()),
-        args: vec![],
-        cwd: Some(root.clone().into()),
-        env: BTreeMap::new(),
-        extra_json: None,
-    };
-    let sink: SharedSink = Arc::new(|_| {});
-    let mapping = TargetMapping {
-        paths: PathMapping::new(&root.to_string_lossy(), "/app"),
-        external_prefix: "openidea-target://fake/0/".into(),
-    };
-    let id = manager
-        .start_prepared(
-            config,
-            SessionOwner::new("test", sink),
-            |_| None,
-            move |spec, _| {
-                spec.command = run.command;
-                spec.args = run.args;
-                spec.cwd = root;
-                spec.target = Some(mapping);
-                Ok(())
-            },
-        )
-        .await
-        .unwrap();
-    let frames = manager.stack_trace(id, 1).await.unwrap();
-    assert_eq!(
-        frames[0].path.as_ref().unwrap().to_string_lossy(),
-        tmp.path().canonicalize().unwrap().join("main.py").to_string_lossy()
-    );
-    assert_eq!(frames[0].line, 2);
-    assert!(std::fs::read_to_string(tmp.path().join("wrapper-argv")).unwrap().starts_with("python3\n-u\n-c\n"));
-    manager.stop(id).await.unwrap();
-}
-
-#[tokio::test]
-async fn host_adapter_accepts_connect_back_from_target_with_mapped_sources() {
-    let tmp = tempfile::tempdir().unwrap();
-    let root = tmp.path().canonicalize().unwrap();
-    let port = ide_dap::adapter::free_port().unwrap();
-    let manager = DebugManager::new(Arc::new(LanguageRegistry::load(None).unwrap()));
-    manager
-        .set_breakpoints(
-            root.join("main.py"),
-            vec![Breakpoint { line: 2, enabled: true, condition: None, hit_condition: None, log_message: None }],
-        )
-        .await
-        .unwrap();
-    let config = LaunchConfig {
-        name: "Connect back".into(),
-        adapter: "php-debug".into(),
-        request: "launch".into(),
-        program: None,
-        args: vec![],
-        cwd: Some(root.clone().into()),
-        env: BTreeMap::new(),
-        extra_json: Some(serde_json::json!({"port":port,"pathMappings":{"/app":"/app"}}).to_string()),
-    };
-    let sink: SharedSink = Arc::new(|_| {});
-    let mapping = TargetMapping {
-        paths: PathMapping::new(&root.to_string_lossy(), "/app"),
-        external_prefix: "openidea-target://fake/0/".into(),
-    };
-    let id = manager
-        .start_prepared(
-            config,
-            SessionOwner::new("test", sink),
-            |_| None,
-            move |spec, _| {
-                spec.command = "/usr/bin/python3".into();
-                spec.args = vec!["-u".into(), "-c".into(), ADAPTER.into()];
-                spec.env.push(("FAKE_CONNECT_BACK".into(), "1".into()));
-                spec.target = Some(mapping);
-                Ok(())
-            },
-        )
-        .await
-        .unwrap();
-    let code =
-        format!("import socket;s=socket.create_connection(('127.0.0.1', {port}));s.sendall(b'/app/main.py');s.close()");
-    let mut child = tokio::process::Command::new("/usr/bin/python3").args(["-c", &code]).spawn().unwrap();
-    let frames = manager.stack_trace(id, 1).await.unwrap();
-    assert_eq!(frames[0].path.as_ref().unwrap().to_path_buf(), root.join("main.py"));
-    assert!(child.wait().await.unwrap().success());
-    manager.stop(id).await.unwrap();
-}

crates/ide-db/Cargo.toml

@@ -20,7 +20,7 @@ parking_lot.workspace = true
 futures.workspace = true
 sqlx.workspace = true
 tiberius.workspace = true
-oracle.workspace = true
+oracledb.workspace = true
 bb8.workspace = true
 tokio-util = { workspace = true, features = ["compat"] }
 dirs.workspace = true

crates/ide-db/src/conn.rs

@@ -417,7 +417,7 @@ fn binary_type(name: &str, text: bool) -> bool {
 }
 
 /// Bytes as text: UTF-8, else hex (grids) or with invalid sequences replaced (catalog names).
-fn bytes_text(bytes: Vec<u8>, mode: Cells) -> String {
+pub(crate) fn bytes_text(bytes: Vec<u8>, mode: Cells) -> String {
     match (String::from_utf8(bytes), mode) {
         (Ok(s), _) => s,
         (Err(e), Cells::Display) => hex(e.as_bytes()),
@@ -594,6 +594,13 @@ fn is_identifier(name: &str) -> bool {
         && chars.all(|c| c.is_ascii_alphanumeric() || c == '_' || c == '.')
 }
 
+/// sqlx's handshake flags for `sql_mode`: with either enabled it sends
+/// `SET sql_mode=(SELECT CONCAT(...))`, a non-constant subquery that MySQL-protocol
+/// servers like StarRocks reject (#2452), so the StarRocks preset turns both off.
+fn mysql_mode_flags(vendor: &str) -> (bool, bool) {
+    if vendor == "starrocks" { (false, false) } else { (true, true) }
+}
+
 /// A MySQL `SET` value: numbers and keywords as they are, anything else quoted.
 fn mysql_value(v: &str) -> String {
     let keyword = ["ON", "OFF", "TRUE", "FALSE", "DEFAULT"].iter().any(|k| k.eq_ignore_ascii_case(v));
@@ -839,6 +846,8 @@ impl Pool {
                 if let Some(c) = &setup.collation {
                     opts = opts.collation(c);
                 }
+                let (pipes_as_concat, no_engine_substitution) = mysql_mode_flags(&source.vendor);
+                opts = opts.pipes_as_concat(pipes_as_concat).no_engine_substitution(no_engine_substitution);
                 if let Some(n) = setup.statement_cache {
                     opts = opts.statement_cache_capacity(n);
                 }
@@ -1033,7 +1042,7 @@ pub enum Held {
     Mysql(Box<bb8::PooledConnection<'static, MysqlManager>>),
     SqlServer(Box<bb8::PooledConnection<'static, MssqlConnectionManager>>),
     Clickhouse(crate::clickhouse::ClickhousePool),
-    Oracle(crate::oracle::OracleConnection),
+    Oracle(Box<crate::oracle::OracleConnection>),
 }
 
 impl Held {
@@ -1049,7 +1058,7 @@ impl Held {
                 }
                 Held::Clickhouse(p.clone())
             }
-            Pool::Oracle(p) => Held::Oracle(p.get().await?),
+            Pool::Oracle(p) => Held::Oracle(Box::new(p.get().await?)),
         })
     }
 
@@ -1465,6 +1474,15 @@ mod tests {
         assert!(Setup::of(&DataSource { properties: vec![prop("connect_timeout", "soon")], ..s }).is_err());
     }
 
+    #[test]
+    fn starrocks_disables_the_non_constant_sql_mode_handshake() {
+        // MySQL and its other wire-compatible presets keep sqlx's defaults.
+        for vendor in ["", "mysql", "mariadb", "tidb"] {
+            assert_eq!(mysql_mode_flags(vendor), (true, true), "{vendor}");
+        }
+        assert_eq!(mysql_mode_flags("starrocks"), (false, false));
+    }
+
     #[test]
     fn sqlite_properties_become_pragmas() {
         let s = DataSource { properties: vec![prop("cache_size", "-2000")], ..Default::default() };

crates/ide-db/src/lib.rs

@@ -57,6 +57,7 @@ impl DbTableKind {
 pub enum DbObjectKind {
     Function,
     Procedure,
+    Package,
     Trigger,
     Sequence,
 }
@@ -92,12 +93,21 @@ pub struct SequenceInfo {
     pub data_type: String,
 }
 
-/// A schema's routines (procedures and functions) and sequences.
+/// An Oracle package (its procedures and functions are not listed separately).
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+#[serde(rename = "DbPackageInfo")]
+pub struct PackageInfo {
+    pub name: String,
+}
+
+/// A schema's routines (procedures and functions), packages and sequences.
 #[derive(Debug, Clone, PartialEq, Eq, Default, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 #[serde(rename = "DbSchemaObjects")]
 pub struct SchemaObjects {
     pub routines: Vec<RoutineInfo>,
+    pub packages: Vec<PackageInfo>,
     pub sequences: Vec<SequenceInfo>,
 }
 
@@ -296,7 +306,7 @@ fn through_tunnel(e: IdeError, source: &DataSource, via: Option<&str>) -> IdeErr
 
 /// Options › Run keep-alive query: pings the pool until it is closed or dropped
 /// (a dropped SSH tunnel or an idle-killing proxy stays alive meanwhile).
-fn keep_alive(pool: &Arc<Pool>, every: Duration) {
+pub(crate) fn keep_alive(pool: &Arc<Pool>, every: Duration) {
     let pool = Arc::downgrade(pool);
     tokio::spawn(async move {
         let mut tick = tokio::time::interval(every);
@@ -853,6 +863,14 @@ impl DbManager {
                 })
                 .collect();
         }
+        if let Some(q) = sql::packages(driver, schema) {
+            out.packages = pool
+                .rows(&q, MAX_META_ROWS)
+                .await?
+                .into_iter()
+                .filter_map(|r| Some(PackageInfo { name: r.into_iter().next().flatten()? }))
+                .collect();
+        }
         if let Some(q) = sql::sequences(driver, schema) {
             out.sequences = pool
                 .rows(&q, MAX_META_ROWS)
@@ -870,9 +888,29 @@ impl DbManager {
         Ok(out)
     }
 
-    /// The definition of a routine (every overload), trigger or sequence.
+    /// The definition of a routine (every overload), package (spec and body), trigger or sequence.
     pub async fn object_ddl(&self, id: &str, schema: &str, kind: DbObjectKind, name: &str) -> IdeResult<String> {
         let pool = self.pool(id).await?;
+        if kind == DbObjectKind::Package {
+            let mut defs: Vec<String> = Vec::new();
+            for body in [false, true] {
+                let Some(q) = sql::package_ddl(pool.driver(), schema, name, body) else { continue };
+                match pool.rows(&q, MAX_META_ROWS).await {
+                    Ok(rows) => defs.extend(rows.into_iter().filter_map(|r| r.into_iter().next().flatten())),
+                    // A spec-only package has no body: the spec alone still opens.
+                    Err(e) if body => tracing::warn!("package body {schema}.{name}: {}", e.message),
+                    Err(e) => return Err(e),
+                }
+            }
+            if defs.is_empty() {
+                return Err(IdeError::not_found(format!("{schema}.{name}")));
+            }
+            return Ok(defs
+                .iter()
+                .map(|d| format!("{};\n", d.trim_end().trim_end_matches(';')))
+                .collect::<Vec<_>>()
+                .join("\n"));
+        }
         let (q, column) = sql::object_ddl(pool.driver(), schema, kind, name)
             .ok_or_else(|| IdeError::invalid(format!("no {kind:?} objects in this database")))?;
         let defs: Vec<String> = pool

crates/ide-db/src/source.rs

@@ -20,7 +20,7 @@ pub enum DbDriver {
     /// Microsoft SQL Server.
     SqlServer,
     Clickhouse,
-    /// Oracle Database (via Oracle Instant Client).
+    /// Oracle Database (pure-Rust thin driver, no client library).
     Oracle,
 }
 
@@ -88,8 +88,6 @@ pub struct DbOptions {
     pub auto_disconnect_secs: Option<u32>,
     /// PostgreSQL: show only the configured database, its schemas right under the data source.
     pub single_database: bool,
-    /// Oracle: directory of the Oracle Instant Client (empty: `ORACLE_HOME` / system search path).
-    pub instant_client: String,
 }
 
 /// Schemas tab: the databases / schemas the tree shows. Names may use `*` and `?`.
@@ -270,7 +268,7 @@ pub fn scheme_driver(scheme: &str) -> Option<DbDriver> {
     match scheme.to_ascii_lowercase().as_str() {
         "postgres" | "postgresql" | "pgsql" | "redshift" | "cockroachdb" | "cockroach" | "yugabytedb"
         | "timescaledb" | "greenplum" => Some(DbDriver::Postgres),
-        "mysql" | "mariadb" | "tidb" | "singlestore" | "memsql" | "oceanbase" => Some(DbDriver::Mysql),
+        "mysql" | "mariadb" | "tidb" | "singlestore" | "memsql" | "oceanbase" | "starrocks" => Some(DbDriver::Mysql),
         "sqlserver" | "mssql" | "mssqlserver" => Some(DbDriver::SqlServer),
         "sqlite" | "sqlite3" => Some(DbDriver::Sqlite),
         "clickhouse" | "http" | "https" => Some(DbDriver::Clickhouse),
@@ -559,6 +557,7 @@ mod tests {
         assert_eq!((u.host.as_str(), u.port, u.user.as_str()), ("::1", None, "root"));
         assert_eq!(parse_url("jdbc:redshift://r:5439/dev").unwrap().driver, Some(DbDriver::Postgres));
         assert_eq!(parse_url("tidb://h:4000").unwrap().driver, Some(DbDriver::Mysql));
+        assert_eq!(parse_url("starrocks://h:9030").unwrap().driver, Some(DbDriver::Mysql));
         assert_eq!(parse_url("sqlite:/tmp/a.db").unwrap().file.as_deref(), Some("/tmp/a.db"));
         let u = parse_url("oracle://scott:[email protected]:1521/ORCLPDB1").unwrap();
         assert_eq!(u.driver, Some(DbDriver::Oracle));

crates/ide-db/src/sql.rs

@@ -664,6 +664,32 @@ pub fn routines(driver: DbDriver, schema: &str) -> Option<String> {
     }
 }
 
+/// Rows: `name` of a schema's packages (Oracle only; their procedures and functions are not
+/// listed separately, as in IDEA).
+pub fn packages(driver: DbDriver, schema: &str) -> Option<String> {
+    match driver {
+        DbDriver::Oracle => Some(format!(
+            "SELECT object_name FROM all_objects WHERE owner = {} AND object_type = 'PACKAGE' \
+             AND object_name NOT LIKE 'BIN$%' ORDER BY 1",
+            quote_literal(driver, schema)
+        )),
+        _ => None,
+    }
+}
+
+/// The statement reading a package's specification (`body` false) or body as DDL.
+pub fn package_ddl(driver: DbDriver, schema: &str, name: &str, body: bool) -> Option<String> {
+    match driver {
+        DbDriver::Oracle => Some(format!(
+            "SELECT DBMS_METADATA.GET_DDL('{}', {}, {}) FROM DUAL",
+            if body { "PACKAGE_BODY" } else { "PACKAGE" },
+            quote_literal(driver, name),
+            quote_literal(driver, schema)
+        )),
+        _ => None,
+    }
+}
+
 /// Rows: `name, data type` of a schema's sequences (PostgreSQL, Oracle).
 pub fn sequences(driver: DbDriver, schema: &str) -> Option<String> {
     match driver {
@@ -963,6 +989,7 @@ mod tests {
         assert!(completion_columns(DbDriver::Oracle).contains("all_tab_columns"));
         assert!(triggers(DbDriver::Oracle, "hr", "t").contains("all_triggers"));
         assert!(routines(DbDriver::Oracle, "hr").unwrap().contains("all_objects"));
+        assert!(packages(DbDriver::Oracle, "hr").unwrap().contains("object_type = 'PACKAGE'"));
         assert!(sequences(DbDriver::Oracle, "hr").unwrap().contains("all_sequences"));
     }
 
@@ -984,6 +1011,17 @@ mod tests {
         let (q, col) = object_ddl(DbDriver::Oracle, "hr", K::Procedure, "p").unwrap();
         assert!(q.contains("DBMS_METADATA.GET_DDL('PROCEDURE'") && col == 0);
         assert!(object_ddl(DbDriver::Oracle, "hr", K::Sequence, "q").unwrap().0.contains("all_sequences"));
+        assert!(
+            package_ddl(DbDriver::Oracle, "hr", "pkg", false)
+                .unwrap()
+                .contains("DBMS_METADATA.GET_DDL('PACKAGE', 'pkg', 'hr')")
+        );
+        assert!(
+            package_ddl(DbDriver::Oracle, "hr", "pkg", true)
+                .unwrap()
+                .contains("DBMS_METADATA.GET_DDL('PACKAGE_BODY', 'pkg', 'hr')")
+        );
+        assert!(package_ddl(DbDriver::Postgres, "public", "pkg", false).is_none());
     }
 
     #[test]
@@ -1001,6 +1039,7 @@ mod tests {
     fn schema_objects_per_dialect() {
         use crate::DbObjectKind as K;
         assert!(routines(DbDriver::Sqlite, "main").is_none());
+        assert!(packages(DbDriver::Sqlite, "main").is_none());
         assert!(sequences(DbDriver::Mysql, "db").is_none());
         assert!(routines(DbDriver::Postgres, "public").unwrap().contains("n.nspname = 'public'"));
         assert_eq!(

crates/ide-docker/src/connection.rs

@@ -136,24 +136,19 @@ pub struct DockerRegistry {
     pub username: String,
 }
 
-#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
 #[serde(rename_all = "camelCase")]
 pub struct DockerSettings {
-    #[serde(default = "default_connections")]
+    #[serde(default)]
     pub connections: Vec<DockerConnection>,
     #[serde(default)]
     pub registries: Vec<DockerRegistry>,
 }
 
-impl Default for DockerSettings {
-    fn default() -> Self {
-        Self { connections: default_connections(), registries: Vec::new() }
-    }
-}
-
-/// Before anything is configured the CLI's own daemon is shown, as before connections existed.
-fn default_connections() -> Vec<DockerConnection> {
-    vec![DockerConnection { id: "default".into(), name: "Docker".into(), endpoint: DockerEndpoint::Default }]
+/// Whether `c` is the connection older versions injected when nothing was configured:
+/// Services lists only connections the user added, so this one is dropped on load.
+fn is_injected_default(c: &DockerConnection) -> bool {
+    c.id == "default" && c.name == "Docker" && c.endpoint == DockerEndpoint::Default
 }
 
 const SETTINGS_FILE: &str = "docker.json";
@@ -161,10 +156,17 @@ const PASSWORDS_FILE: &str = "docker-passwords.json";
 
 pub fn load_settings(data_dir: &Path) -> DockerSettings {
     match std::fs::read(data_dir.join(SETTINGS_FILE)) {
-        Ok(bytes) => serde_json::from_slice(&bytes).unwrap_or_else(|e| {
-            tracing::warn!("{SETTINGS_FILE}: {e}");
-            DockerSettings::default()
-        }),
+        // A file written before the opt-in Services rework carries the injected default
+        // (saved along with a registry or another connection); drop it unless edited.
+        Ok(bytes) => serde_json::from_slice(&bytes)
+            .map(|mut s: DockerSettings| {
+                s.connections.retain(|c| !is_injected_default(c));
+                s
+            })
+            .unwrap_or_else(|e| {
+                tracing::warn!("{SETTINGS_FILE}: {e}");
+                DockerSettings::default()
+            }),
         Err(_) => DockerSettings::default(),
     }
 }
@@ -373,7 +375,8 @@ mod tests {
     fn settings_round_trip_and_passwords() {
         let tmp = tempfile::tempdir().unwrap();
         let dir = tmp.path();
-        assert_eq!(load_settings(dir).connections[0].endpoint, DockerEndpoint::Default);
+        // Nothing configured: no connection is invented.
+        assert!(load_settings(dir).connections.is_empty());
         let settings = DockerSettings {
             connections: vec![DockerConnection {
                 id: "c1".into(),
@@ -395,8 +398,32 @@ mod tests {
         assert!(auth_for(dir, "postgres").is_none());
         save_settings(dir, &DockerSettings { registries: Vec::new(), ..settings }).unwrap();
         assert_eq!(registry_password(dir, "r1"), None);
-        // An empty list stays empty (the default connection is only for a missing file).
+        // An empty list stays empty.
         save_settings(dir, &DockerSettings { connections: Vec::new(), registries: Vec::new() }).unwrap();
         assert!(load_settings(dir).connections.is_empty());
     }
+
+    #[test]
+    fn load_drops_the_injected_default_connection() {
+        let tmp = tempfile::tempdir().unwrap();
+        let dir = tmp.path();
+        let injected =
+            || DockerConnection { id: "default".into(), name: "Docker".into(), endpoint: DockerEndpoint::Default };
+        let registry =
+            DockerRegistry { id: "r1".into(), name: "GHCR".into(), address: "ghcr.io".into(), username: "me".into() };
+        // Saved untouched by an older version (e.g. along with a registry): dropped on load.
+        save_settings(dir, &DockerSettings { connections: vec![injected()], registries: vec![registry.clone()] })
+            .unwrap();
+        let loaded = load_settings(dir);
+        assert!(loaded.connections.is_empty());
+        assert_eq!(loaded.registries, vec![registry]);
+        // A connection the user renamed or re-pointed stays theirs.
+        let renamed = DockerConnection { name: "Local engine".into(), ..injected() };
+        save_settings(dir, &DockerSettings { connections: vec![renamed.clone()], registries: Vec::new() }).unwrap();
+        assert_eq!(load_settings(dir).connections, vec![renamed]);
+        let repointed =
+            DockerConnection { endpoint: DockerEndpoint::Socket { path: "/var/run/docker.sock".into() }, ..injected() };
+        save_settings(dir, &DockerSettings { connections: vec![repointed.clone()], registries: Vec::new() }).unwrap();
+        assert_eq!(load_settings(dir).connections, vec![repointed]);
+    }
 }

crates/ide-extension/Cargo.toml

@@ -18,6 +18,7 @@ semver = "1"
 blake3.workspace = true
 zip.workspace = true
 base64.workspace = true
+dunce.workspace = true
 ed25519-dalek = "3"
 
 [dev-dependencies]

crates/ide-extension/src/capability.rs

@@ -38,6 +38,10 @@ pub enum Capability {
     Clipboard,
     /// HTTPS (and loopback HTTP) to one host (`*.example.com` matches subdomains).
     Net(String),
+    /// Ask the user when the first request goes to an HTTPS (or loopback) host
+    /// the manifest does not list; each answer applies to one host. Plain
+    /// HTTP elsewhere always needs `net.http:<host>`.
+    NetAsk,
     /// Unencrypted HTTP to one host.
     NetHttp(String),
     /// A local socket or named pipe on the project machine.
@@ -67,15 +71,22 @@ impl Capability {
         match self {
             Self::ProjectRead | Self::EditorRead | Self::Storage | Self::Events | Self::VcsRead => Risk::Low,
             Self::EditorWrite
-            | Self::ProjectWrite
             | Self::DatabaseSources
             | Self::VcsWrite
             | Self::Net(_)
+            | Self::NetAsk
             | Self::NetHttp(_)
             | Self::Secrets
             | Self::InputEvents
             | Self::Clipboard => Risk::Medium,
-            Self::IdeCommands | Self::Ipc(_) | Self::Process(_) | Self::FsRead(_) | Self::FsWrite(_) => Risk::High,
+            // A trusted project's own files name the programs the IDE starts (its settings, its
+            // build scripts), so writing them is running code.
+            Self::ProjectWrite
+            | Self::IdeCommands
+            | Self::Ipc(_)
+            | Self::Process(_)
+            | Self::FsRead(_)
+            | Self::FsWrite(_) => Risk::High,
         }
     }
 
@@ -104,6 +115,10 @@ impl Capability {
                 "Copy to the clipboard from its commands, and read and write it from its web views".into()
             }
             Self::Net(host) => format!("Connect to {host} (from the machine the project is on)"),
+            Self::NetAsk => {
+                "Ask to connect to a host that is not on the list the first time it tries; you allow or refuse each host, and can revoke the allowed ones"
+                    .into()
+            }
             Self::NetHttp(host) => {
                 format!("Connect to {host} over unencrypted HTTP (from the machine the project is on)")
             }
@@ -230,6 +245,7 @@ impl fmt::Display for Capability {
             Self::InputEvents => f.write_str("events.input"),
             Self::Clipboard => f.write_str("clipboard"),
             Self::Net(h) => write!(f, "net:{h}"),
+            Self::NetAsk => f.write_str("net:ask"),
             Self::NetHttp(h) => write!(f, "net.http:{h}"),
             Self::Ipc(p) => write!(f, "ipc:{p}"),
             Self::Process(b) => write!(f, "process:{b}"),
@@ -251,6 +267,9 @@ impl FromStr for Capability {
             }
             return match kind {
                 "net" | "net.http" => {
+                    if kind == "net" && arg == "ask" {
+                        return Ok(Self::NetAsk);
+                    }
                     let host = arg.strip_prefix("*.").unwrap_or(arg);
                     let valid = !host.is_empty()
                         && host.len() <= 253
@@ -389,6 +408,15 @@ mod tests {
         assert!(Capability::Storage.auto_migrates() && !Capability::EditorWrite.auto_migrates());
     }
 
+    /// A trusted project's files name programs the IDE starts by itself: the git and language
+    /// server executables in `.openidea/settings.toml`, its build scripts. Writing them is
+    /// running code, and the install dialog says so.
+    #[test]
+    fn writing_project_files_is_a_high_risk_grant() {
+        assert_eq!(Capability::ProjectWrite.risk(), Risk::High);
+        assert!(!Capability::ProjectWrite.auto_migrates());
+    }
+
     #[test]
     fn host_patterns() {
         assert!(host_matches("crates.io", "crates.io"));
@@ -451,6 +479,25 @@ mod command_tests {
     }
 }
 
+#[cfg(test)]
+mod net_ask_tests {
+    use super::*;
+    #[test]
+    fn net_ask_is_its_own_medium_risk_grant_covering_no_host() {
+        let cap: Capability = "net:ask".parse().unwrap();
+        assert_eq!(cap, Capability::NetAsk);
+        assert_eq!(cap.to_string(), "net:ask");
+        assert_eq!(cap.risk(), Risk::Medium);
+        assert!(!cap.auto_migrates());
+        // It asks; it does not itself connect anywhere or pre-approve a host.
+        assert!(!cap.covers(&"net:api.example.com".parse().unwrap()));
+        assert!(!cap.covers(&Capability::NetHttp("example.com".into())));
+        assert!(!"net:api.example.com".parse::<Capability>().unwrap().covers(&cap));
+        assert_ne!("net:ask.com".parse::<Capability>().unwrap(), Capability::NetAsk);
+        assert!("net:ask".parse::<Capability>().unwrap().describe().contains("host"));
+    }
+}
+
 #[cfg(test)]
 mod database_tests {
     use super::*;

crates/ide-extension/src/ledger.rs

@@ -53,6 +53,9 @@ pub struct Grant {
     /// Granted capabilities (`project.read`, `net:x`, …).
     #[serde(default)]
     pub granted: BTreeSet<String>,
+    /// Exact hosts approved through `net:ask`, separate from manifest grants.
+    #[serde(default)]
+    pub net_hosts: BTreeSet<String>,
     /// Optional capabilities the user declined (not asked again until re-confirmed).
     #[serde(default)]
     pub declined: BTreeSet<String>,
@@ -201,6 +204,9 @@ impl Ledger {
         let Some(grant) = self.grants.get_mut(&req.subject) else {
             return Decision::NeedsConfirmation { new: req.required.clone(), first_time: true };
         };
+        if !req.required.iter().chain(&req.optional).any(|c| c == &Capability::NetAsk) {
+            grant.net_hosts.clear();
+        }
         if !grant.confirmed {
             return Decision::NeedsConfirmation { new: req.required.clone(), first_time: true };
         }
@@ -225,6 +231,9 @@ impl Ledger {
         binaries: BTreeMap<String, BinaryGrant>,
     ) {
         let grant = self.grants.entry(req.subject.clone()).or_default();
+        if !req.required.iter().chain(&req.optional).any(|c| c == &Capability::NetAsk) {
+            grant.net_hosts.clear();
+        }
         grant.plugin_id = req.plugin_id.to_owned();
         grant.version = req.version.to_owned();
         grant.package_hash = req.package_hash.to_owned();
@@ -252,6 +261,12 @@ impl Ledger {
             grant.declined.remove(&s);
             grant.granted.insert(s)
         } else {
+            if let Capability::Net(host) = cap {
+                return grant.net_hosts.remove(host) | grant.granted.remove(&s);
+            }
+            if cap == &Capability::NetAsk {
+                grant.net_hosts.clear();
+            }
             if let Capability::Process(_) = cap {
                 grant.binaries.remove(&s);
                 for binaries in grant.project_binaries.values_mut() {
@@ -262,6 +277,19 @@ impl Ledger {
         }
     }
 
+    /// Remembers one exact host without granting a manifest capability.
+    pub fn remember_net_host(&mut self, subject: &Subject, host: &str) -> bool {
+        let Some(grant) = self.grants.get_mut(subject) else { return false };
+        if !grant.confirmed || !grant.has(&Capability::NetAsk) || host.contains('*') {
+            return false;
+        }
+        grant.net_hosts.insert(host.to_owned())
+    }
+
+    pub fn forget_net_host(&mut self, subject: &Subject, host: &str) -> bool {
+        self.grants.get_mut(subject).is_some_and(|g| g.net_hosts.remove(host))
+    }
+
     /// Records the program approved for a `process:` grant.
     pub fn set_binary(&mut self, subject: &Subject, cap: &Capability, binary: BinaryGrant) {
         if let Some(grant) = self.grants.get_mut(subject) {
@@ -392,7 +420,13 @@ pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf,
         return if candidate.is_file() { Ok(candidate.to_path_buf()) } else { Err(format!("{name}: no such program")) };
     }
     let exts: Vec<String> = if cfg!(windows) {
-        std::env::var("PATHEXT").unwrap_or_else(|_| ".EXE;.CMD;.BAT".into()).split(';').map(str::to_owned).collect()
+        let pathext = std::env::var("PATHEXT").unwrap_or_else(|_| ".EXE;.CMD;.BAT".into());
+        let pathext: Vec<String> = pathext.split(';').filter(|e| !e.is_empty()).map(str::to_owned).collect();
+        // A name given with its extension (`cargo.exe`) is looked up as written.
+        let has_ext = candidate.extension().is_some_and(|e| {
+            pathext.iter().any(|x| x.trim_start_matches('.').eq_ignore_ascii_case(&e.to_string_lossy()))
+        });
+        if has_ext { vec![String::new()] } else { pathext }
     } else {
         vec![String::new()]
     };
@@ -413,11 +447,13 @@ pub fn resolve_program(name: &str, path_var: Option<&OsStr>) -> Result<PathBuf,
 /// `p` with its parent canonicalized but the file name as found: PATH
 /// entries like `/var` → `/private/var` (macOS) or `~` links collapse to
 /// their real directory, while a linked program (`cargo` → rustup) keeps
-/// its link name so the shim still dispatches on argv[0].
+/// its link name so the shim still dispatches on argv[0]. `dunce` keeps the
+/// path in its usual form on Windows: a `\\?\`-prefixed pin would never
+/// match the path the program was actually started with.
 fn canonical_dir(p: &Path) -> PathBuf {
     let Some(dir) = p.parent() else { return p.to_path_buf() };
     let Some(name) = p.file_name() else { return p.to_path_buf() };
-    std::fs::canonicalize(dir).map(|d| d.join(name)).unwrap_or_else(|_| p.to_path_buf())
+    dunce::canonicalize(dir).map(|d| d.join(name)).unwrap_or_else(|_| p.to_path_buf())
 }
 
 fn is_executable(p: &Path) -> bool {
@@ -470,6 +506,20 @@ mod tests {
         list.iter().map(|s| s.parse().unwrap()).collect()
     }
 
+    #[test]
+    #[cfg(windows)]
+    fn pinned_program_path_has_no_verbatim_prefix() {
+        // std::fs::canonicalize returns \\?\-prefixed paths on Windows; a pin
+        // stored in that form would never match the plain path the program is
+        // started with. dunce keeps the usual form.
+        let dir = tempfile::tempdir().unwrap();
+        std::fs::write(dir.path().join("cargo.exe"), b"").unwrap();
+        let pinned = resolve_program("cargo.exe", Some(dir.path().as_os_str())).unwrap();
+        let shown = pinned.to_string_lossy();
+        assert!(!shown.starts_with(r"\\?\"), "verbatim prefix leaked into the pin: {shown}");
+        assert!(pinned.is_absolute());
+    }
+
     fn req<'a>(version: &'a str, hash: &'a str, required: &[&str], optional: &[&str]) -> Request<'a> {
         Request {
             subject: Subject::Installed("p".into()),
@@ -510,6 +560,40 @@ mod tests {
         assert!(matches!(l.decide(&r3), Decision::NeedsConfirmation { .. }));
     }
 
+    #[test]
+    fn net_ask_hosts_persist_revoke_and_drop_with_the_capability() {
+        let tmp = tempfile::tempdir().unwrap();
+        let mut l = Ledger::load(tmp.path());
+        let r = req("1.0.0", "h", &["net:ask"], &[]);
+        l.confirm(&r, &[], BTreeMap::new());
+        let host = "api.example.com";
+        assert!(l.remember_net_host(&r.subject, host));
+        assert!(!l.remember_net_host(&r.subject, "*.example.com"));
+        assert!(!l.get(&r.subject).unwrap().has(&Capability::Net(host.into())));
+        l.save().unwrap();
+        l = Ledger::load(tmp.path());
+        assert!(l.get(&r.subject).unwrap().net_hosts.contains(host));
+        l.confirm(&r, &[], BTreeMap::new());
+        assert!(l.get(&r.subject).unwrap().net_hosts.contains(host));
+        assert!(l.set(&r.subject, &Capability::Net(host.into()), false));
+        assert!(l.get(&r.subject).unwrap().net_hosts.is_empty());
+
+        for confirm in [false, true] {
+            l.remember_net_host(&r.subject, host);
+            // A newly declared host must not inherit an ask grant after net:ask is removed.
+            let update = req("2.0.0", "h2", &["project.read", "net:api.example.com"], &[]);
+            if confirm {
+                l.confirm(&update, &[], BTreeMap::new());
+            } else {
+                assert!(matches!(l.decide(&update), Decision::NeedsConfirmation { .. }));
+            }
+            assert!(l.get(&r.subject).unwrap().net_hosts.is_empty());
+        }
+        l.remember_net_host(&r.subject, host);
+        l.set(&r.subject, &Capability::NetAsk, false);
+        assert!(l.get(&r.subject).unwrap().net_hosts.is_empty());
+    }
+
     #[test]
     fn migration_grants_low_risk_only() {
         let tmp = tempfile::tempdir().unwrap();

crates/ide-extension/src/lib.rs

@@ -19,8 +19,10 @@ mod index;
 pub mod ledger;
 mod manifest;
 pub mod package;
+mod plugin_point;
 mod point;
 mod registry;
+mod resolve;
 mod ui;
 mod when;
 
@@ -30,7 +32,12 @@ pub use manifest::{
     ActivationEvent, CATEGORIES, Capabilities, ENGINE_VERSION, EVENT_KINDS, LEGACY_API, MANIFEST_FILE, MAX_CATEGORIES,
     Manifest, check_relative, engine_compatible, validate_item_id, validate_plugin_id, validate_point_id,
 };
+pub use plugin_point::{FieldType, PointDecl};
 pub use point::{Commit, Disposable, ExtensionPoint, MAX_PACKAGE_FILE, Package, Placement, Prepared, decode};
-pub use registry::{ContributionInfo, ExtensionRegistry, LOCALES_DIR, LOCALES_POINT, PreparedSet};
+pub use registry::{
+    ChangeListener, Contribution, ContributionInfo, DeclaredPoint, ExtensionRegistry, LOCALES_DIR, LOCALES_POINT,
+    PreparedSet,
+};
+pub use resolve::{Blocked, Dependency, DependencyState, Node, Plan, dependency_state, dependents, plan};
 pub use ui::{UiContribution, UiDecl, UiPoint, UiStore, to_json};
 pub use when::validate_when;

crates/ide-extension/src/manifest.rs

@@ -26,6 +26,8 @@
 //! activated at start-up, as before.
 
 use crate::capability::Capability;
+use crate::plugin_point::PointDecl;
+use crate::resolve::Dependency;
 use serde::Deserialize;
 use std::collections::BTreeSet;
 use std::path::{Component, Path, PathBuf};
@@ -66,6 +68,10 @@ pub struct Manifest {
     pub wasm: Option<PathBuf>,
     pub activation: Vec<ActivationEvent>,
     pub capabilities: Capabilities,
+    /// `[[depends]]`: plugins this one needs (API 1.5).
+    pub depends: Vec<Dependency>,
+    /// `[[extension-points]]`: what other plugins may contribute to this one (API 1.5).
+    pub extension_points: Vec<PointDecl>,
     /// `contributes.<point>` → its declarations, validated by the extension points.
     pub contributes: toml::Table,
 }
@@ -151,6 +157,7 @@ pub const EVENT_KINDS: &[&str] = &[
     "file-closed",
     "settings-changed",
     "input-mode-changed",
+    "extensions-changed",
     "file-opened",
     "file-saved",
     "files-changed",
@@ -210,6 +217,10 @@ struct Raw {
     #[serde(default)]
     permissions: Option<Vec<String>>,
     #[serde(default)]
+    depends: Vec<Dependency>,
+    #[serde(default)]
+    extension_points: Vec<PointDecl>,
+    #[serde(default)]
     contributes: toml::Table,
 }
 
@@ -281,6 +292,8 @@ impl Manifest {
             wasm: raw.wasm,
             activation,
             capabilities,
+            depends: raw.depends,
+            extension_points: raw.extension_points,
             contributes: raw.contributes,
         };
         m.validate()?;
@@ -338,6 +351,9 @@ impl Manifest {
             if matches!(cap, Capability::ProjectWrite | Capability::FsWrite(_)) {
                 self.needs_api(&format!("capability `{cap}`"), 3)?;
             }
+            if matches!(cap, Capability::NetAsk) {
+                self.needs_api(&format!("capability `{cap}`"), 5)?;
+            }
         }
         if let Some(dark) = &self.icon_dark {
             if self.icon.is_none() {
@@ -354,6 +370,9 @@ impl Manifest {
             {
                 self.needs_api(&format!("`{event}`"), 4)?;
             }
+            if matches!(event, ActivationEvent::Event(kind) if kind == "extensions-changed") {
+                self.needs_api("`on-event:extensions-changed`", 5)?;
+            }
             if matches!(event, ActivationEvent::Event(kind) if kind == "files-changed") {
                 self.needs_api("`on-event:files-changed`", 3)?;
             }
@@ -364,6 +383,7 @@ impl Manifest {
         for c in &self.declared_categories {
             validate_item_id(c, "category")?;
         }
+        self.validate_relations()?;
         for (point, decls) in &self.contributes {
             validate_point_id(point)?;
             if !matches!(decls, toml::Value::Array(_) | toml::Value::Table(_)) {
@@ -373,6 +393,42 @@ impl Manifest {
         Ok(())
     }
 
+    /// `[[depends]]` and `[[extension-points]]`.
+    fn validate_relations(&self) -> Result<(), String> {
+        if !self.depends.is_empty() {
+            self.needs_api("`[[depends]]`", 5)?;
+        }
+        if !self.extension_points.is_empty() {
+            self.needs_api("`[[extension-points]]`", 5)?;
+        }
+        let mut required = BTreeSet::new();
+        for dep in &self.depends {
+            validate_plugin_id(&dep.id)?;
+            if dep.id == self.id {
+                return Err(format!("`depends`: {} cannot depend on itself", self.id));
+            }
+            if let Some(req) = &dep.version
+                && semver::VersionReq::parse(req).is_err()
+            {
+                return Err(format!(
+                    "`depends`: {:?} is not a version requirement like \"^1.2\" (plugin {})",
+                    req, dep.id
+                ));
+            }
+            if !required.insert(&dep.id) {
+                return Err(format!("`depends`: {} is listed twice", dep.id));
+            }
+        }
+        let mut declared = BTreeSet::new();
+        for point in &self.extension_points {
+            point.validate(&self.id)?;
+            if !declared.insert(&point.id) {
+                return Err(format!("extension point {} is declared twice", point.id));
+            }
+        }
+        Ok(())
+    }
+
     /// The declarations of one extension point: `[[contributes.x]]` gives
     /// several, `[contributes.x]` one.
     pub fn declarations(&self, point: &str) -> Vec<toml::Value> {
@@ -469,11 +525,12 @@ pub fn validate_item_id(id: &str, what: &str) -> Result<(), String> {
 }
 
 /// Extension point ids: `camelCase` or `kebab-case` words, dots allowed (`iconThemes`, `menus`).
+/// Points declared by plugins are `<plugin id>.<name>`, which may be longer and contain `_`.
 pub fn validate_point_id(id: &str) -> Result<(), String> {
     let ok = !id.is_empty()
-        && id.len() <= 64
+        && id.len() <= 128
         && id.starts_with(|c: char| c.is_ascii_lowercase())
-        && id.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '.'));
+        && id.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '.' | '_'));
     if ok { Ok(()) } else { Err(format!("invalid contribution point {id:?}")) }
 }
 
@@ -708,6 +765,86 @@ mod api14_tests {
     }
 }
 
+#[cfg(test)]
+mod relations_tests {
+    use super::*;
+
+    const HEAD: &str = "id = \"acme.app\"\nname = \"App\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.5\"\n";
+
+    fn parse(rest: &str) -> Result<Manifest, String> {
+        Manifest::parse(&format!("{HEAD}{rest}"))
+    }
+
+    #[test]
+    fn parses_depends_and_extension_points() {
+        let m = parse(
+            r#"
+            [[depends]]
+            id = "acme.base"
+            version = "^0.2"
+
+            [[depends]]
+            id = "acme.extra"
+            optional = true
+
+            [[extension-points]]
+            id = "acme.app.hooks"
+            required = ["name"]
+            fields = { name = "string" }
+
+            [[contributes."acme.base.things"]]
+            name = "x"
+            "#,
+        )
+        .unwrap();
+        assert_eq!(m.depends.len(), 2);
+        assert_eq!(m.depends[0].version.as_deref(), Some("^0.2"));
+        assert!(m.depends[1].optional);
+        assert_eq!(m.extension_points[0].id, "acme.app.hooks");
+        assert_eq!(m.declarations("acme.base.things").len(), 1);
+    }
+
+    #[test]
+    fn the_new_keys_need_api_1_5() {
+        let older =
+            "id = \"acme.app\"\nname = \"App\"\nversion = \"1.0.0\"\nwasm = \"p.wasm\"\nengines.openidea = \"^1.4\"\n";
+        let err = Manifest::parse(&format!("{older}[[depends]]\nid = \"acme.base\"\n")).unwrap_err();
+        assert!(err.contains("new in plugin API 1.5"), "{err}");
+        let err = Manifest::parse(&format!("{older}[[extension-points]]\nid = \"acme.app.x\"\n")).unwrap_err();
+        assert!(err.contains("new in plugin API 1.5"), "{err}");
+        let err = Manifest::parse(&format!("{older}activation = [\"on-event:extensions-changed\"]\n")).unwrap_err();
+        assert!(err.contains("new in plugin API 1.5"), "{err}");
+        let current = older.replace("^1.4", "^1.5");
+        assert!(Manifest::parse(&format!("{current}activation = [\"on-event:extensions-changed\"]\n")).is_ok());
+    }
+
+    #[test]
+    fn refuses_bad_dependencies() {
+        assert!(parse("[[depends]]\nid = \"acme.app\"\n").unwrap_err().contains("itself"));
+        assert!(parse("[[depends]]\nid = \"Bad Id\"\n").unwrap_err().contains("invalid plugin id"));
+        assert!(
+            parse("[[depends]]\nid = \"acme.base\"\nversion = \"one\"\n").unwrap_err().contains("version requirement")
+        );
+        let twice = "[[depends]]\nid = \"acme.base\"\n[[depends]]\nid = \"acme.base\"\n";
+        assert!(parse(twice).unwrap_err().contains("listed twice"));
+        assert!(parse("[[depends]]\nid = \"acme.base\"\nunknown = 1\n").is_err());
+    }
+
+    #[test]
+    fn refuses_points_outside_the_plugins_namespace() {
+        let err = parse("[[extension-points]]\nid = \"other.thing\"\n").unwrap_err();
+        assert!(err.contains("acme.app.<name>"), "{err}");
+        let twice = "[[extension-points]]\nid = \"acme.app.x\"\n[[extension-points]]\nid = \"acme.app.x\"\n";
+        assert!(parse(twice).unwrap_err().contains("declared twice"));
+    }
+
+    #[test]
+    fn plugin_ids_with_underscores_work_as_contribution_keys() {
+        assert!(validate_point_id("my_tools.base.things").is_ok());
+        assert!(validate_point_id("Bad").is_err());
+    }
+}
+
 #[cfg(test)]
 mod commands_api_tests {
     use super::*;
@@ -718,3 +855,24 @@ mod commands_api_tests {
         assert!(Manifest::parse(&manifest.replace("^1.3", "^1.4")).is_ok());
     }
 }
+
+#[cfg(test)]
+mod net_ask_api_tests {
+    use super::*;
+    #[test]
+    fn net_ask_requires_api_1_5() {
+        for declaration in ["[capabilities]\nrequired = [\"net:ask\"]", "[capabilities]\noptional = [\"net:ask\"]"] {
+            for engine in ["^1.4", "^1.5"] {
+                let manifest = format!(
+                    "id = 'test'\nname = 'Test'\nversion = '0.1.0'\nwasm = 'plugin.wasm'\nengines.openidea = '{engine}'\n{declaration}\n"
+                );
+                let parsed = Manifest::parse(&manifest);
+                if engine == "^1.5" {
+                    parsed.unwrap();
+                } else {
+                    assert!(parsed.unwrap_err().contains("new in plugin API 1.5"), "{engine}");
+                }
+            }
+        }
+    }
+}

crates/ide-extension/src/package.rs

@@ -352,6 +352,22 @@ pub struct IndexEntry {
     /// the IDE before showing it.
     #[serde(default)]
     pub icon: Option<PluginIcon>,
+    /// Where to read more: the manifest's homepage, else the registry's source repository.
+    #[serde(default)]
+    pub homepage: Option<String>,
+    /// This version's release notes (the manifest's `change-notes`).
+    #[serde(default)]
+    pub notes: Option<String>,
+    /// Downloads of the plugin's packages, as counted by whoever serves them.
+    #[serde(default)]
+    pub downloads: Option<u64>,
+    /// Picked by the marketplace's maintainers.
+    #[serde(default)]
+    pub featured: bool,
+    /// Project-relative paths whose presence makes the plugin worth suggesting
+    /// (`pom.xml`, `config/routes.rb`).
+    #[serde(default)]
+    pub suggest: Vec<String>,
 }
 
 impl IndexEntry {
@@ -389,10 +405,31 @@ impl Index {
     /// revocations, publisher keys (revoked ones) and `moved` — and lists no
     /// plugins ([`Index::is_newer`]): the IDE needs updating to install from it.
     pub fn parse(text: &str) -> Result<Self, String> {
+        let (index, dropped) = Self::parse_dropping(text)?;
+        if let Some(first) = dropped.first() {
+            // One line per index, and a bounded one: whoever wrote the index chose the text.
+            let id: String = first.id.chars().take(80).collect();
+            tracing::warn!(
+                "index: {} entries are not offered, their id or version is not one a manifest may carry (first: {id:?})",
+                dropped.len()
+            );
+        }
+        Ok(index)
+    }
+
+    /// [`Index::parse`], with the entries it does not offer: those whose id or
+    /// version no manifest may carry, so no IDE could install them.
+    pub fn parse_dropping(text: &str) -> Result<(Self, Vec<IndexEntry>), String> {
         let value: serde_json::Value = serde_json::from_str(text).map_err(|e| format!("index: {e}"))?;
         let format = value.get("format").and_then(serde_json::Value::as_u64).ok_or("index: `format` is missing")?;
         if format == u64::from(INDEX_FORMAT) {
-            return serde_json::from_value(value).map_err(|e| format!("index: {e}"));
+            let mut index: Index = serde_json::from_value(value).map_err(|e| format!("index: {e}"))?;
+            // What no manifest may carry is not offered: the id and version also name files on disk.
+            let (offered, dropped) = std::mem::take(&mut index.plugins)
+                .into_iter()
+                .partition(|e| crate::validate_plugin_id(&e.id).is_ok() && e.semver().is_some());
+            index.plugins = offered;
+            return Ok((index, dropped));
         }
         if format < u64::from(INDEX_FORMAT) {
             return Err(format!("index format {format} is not supported (this IDE reads {INDEX_FORMAT})"));
@@ -401,13 +438,14 @@ impl Index {
             let items = value.get(field).and_then(serde_json::Value::as_array);
             items.into_iter().flatten().filter_map(|v| serde_json::from_value(v.clone()).ok()).collect()
         }
-        Ok(Index {
+        let index = Index {
             format: u32::try_from(format).unwrap_or(u32::MAX),
             publishers: each(&value, "publishers"),
             plugins: Vec::new(),
             revoked: each(&value, "revoked"),
             moved: value.get("moved").and_then(serde_json::Value::as_str).map(str::to_owned),
-        })
+        };
+        Ok((index, Vec::new()))
     }
 
     /// Written in a format newer than this IDE reads: it lists no plugins.
@@ -685,9 +723,33 @@ mod tests {
             engine: "^1.0".into(),
             categories: Vec::new(),
             icon: None,
+            homepage: None,
+            notes: None,
+            downloads: None,
+            featured: false,
+            suggest: Vec::new(),
         }
     }
 
+    #[test]
+    fn listing_details_are_optional() {
+        let mut json = serde_json::to_value(entry("acme.a", "acme")).unwrap();
+        for key in ["homepage", "notes", "downloads", "featured", "suggest"] {
+            json.as_object_mut().unwrap().remove(key);
+        }
+        assert_eq!(serde_json::from_value::<IndexEntry>(json).unwrap(), entry("acme.a", "acme"));
+        let full = IndexEntry {
+            homepage: Some("https://example.com".into()),
+            notes: Some("Fixes".into()),
+            downloads: Some(42),
+            featured: true,
+            suggest: vec!["pom.xml".into()],
+            ..entry("acme.a", "acme")
+        };
+        let back: IndexEntry = serde_json::from_str(&serde_json::to_string(&full).unwrap()).unwrap();
+        assert_eq!(back, full);
+    }
+
     fn version(id: &str, version: &str, engine: &str) -> IndexEntry {
         IndexEntry { version: version.into(), engine: engine.into(), ..entry(id, "acme") }
     }
@@ -868,6 +930,51 @@ mod tests {
         }
     }
 
+    #[test]
+    fn an_index_offers_only_the_ids_and_versions_a_manifest_may_carry() {
+        let invalid_ids = [
+            "../x",
+            "../../escape",
+            "acme/../x",
+            r"acme.\..\x",
+            "acme./../../../escape",
+            "/abs",
+            r"C:\x",
+            "ACME.x",
+            "acme.",
+            "acme..x",
+            "acme.x y",
+            "",
+        ];
+        let invalid_versions =
+            ["../1.0.0", "1.0.0/../../../escape", r"1.0.0\..\x", "1.0.0-..", " 1.0.0", "1.0", "latest", ""];
+        let valid = [("acme.x", "1.0.0"), ("acme.tools-2_b", "1.0.0-rc.1+b.2")];
+        let mut listed: Vec<(&str, &str)> = valid.to_vec();
+        listed.extend(invalid_ids.iter().map(|id| (*id, "1.0.0")));
+        listed.extend(invalid_versions.iter().map(|version| ("acme.x", *version)));
+        let plugins: Vec<serde_json::Value> = listed
+            .iter()
+            .map(|(id, version)| {
+                serde_json::json!({
+                    "id": id, "name": "X", "version": version, "publisher": "acme",
+                    "download": "x.oiplugin", "digest": "d", "engine": "^1.0",
+                })
+            })
+            .collect();
+        let text = serde_json::json!({ "format": INDEX_FORMAT, "plugins": plugins }).to_string();
+        let pairs = |entries: &[IndexEntry]| -> Vec<(String, String)> {
+            entries.iter().map(|e| (e.id.clone(), e.version.clone())).collect()
+        };
+        let owned = |pairs: &[(&str, &str)]| -> Vec<(String, String)> {
+            pairs.iter().map(|(id, version)| ((*id).to_owned(), (*version).to_owned())).collect()
+        };
+
+        assert_eq!(pairs(&Index::parse(&text).unwrap().plugins), owned(&valid));
+        let (index, dropped) = Index::parse_dropping(&text).unwrap();
+        assert_eq!(pairs(&index.plugins), owned(&valid));
+        assert_eq!(pairs(&dropped), owned(&listed[valid.len()..]));
+    }
+
     #[test]
     fn a_newer_index_still_revokes_and_moves() {
         let newer = format!(

crates/ide-extension/src/plugin_point.rs

@@ -0,0 +1,192 @@
+//! Extension points a plugin declares for other plugins to contribute to
+//! (`[[extension-points]]`), and the check of a contribution against them.
+
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::BTreeMap;
+
+const MAX_FIELDS: usize = 32;
+const MAX_ID: usize = 128;
+/// Longest string a contribution may carry in one field.
+const MAX_TEXT: usize = 64 * 1024;
+const MAX_LIST: usize = 1000;
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "kebab-case")]
+pub enum FieldType {
+    String,
+    Boolean,
+    Integer,
+    Number,
+    StringList,
+}
+
+/// `[[extension-points]]`: a kind of contribution the declaring plugin's code reads.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(deny_unknown_fields)]
+pub struct PointDecl {
+    /// `<plugin id>.<name>`.
+    pub id: String,
+    #[serde(default)]
+    pub description: String,
+    /// Fields a contribution must have.
+    #[serde(default)]
+    pub required: Vec<String>,
+    /// Every field a contribution may have; a contribution with another key is refused.
+    #[serde(default)]
+    pub fields: BTreeMap<String, FieldType>,
+}
+
+impl PointDecl {
+    pub fn validate(&self, plugin_id: &str) -> Result<(), String> {
+        let prefix = format!("{plugin_id}.");
+        let name = self.id.strip_prefix(&prefix).unwrap_or("");
+        let name_ok = name.chars().next().is_some_and(|c| c.is_ascii_lowercase() || c.is_ascii_digit())
+            && name.chars().all(|c| c.is_ascii_lowercase() || c.is_ascii_digit() || matches!(c, '-' | '_' | '.'));
+        if !name_ok || self.id.len() > MAX_ID {
+            return Err(format!(
+                "invalid extension point {:?}: use \"{plugin_id}.<name>\" with a-z, 0-9, '.', '-', '_' in the name",
+                self.id
+            ));
+        }
+        if self.description.len() > 500 {
+            return Err(format!("extension point {}: `description` is longer than 500 characters", self.id));
+        }
+        if self.fields.len() > MAX_FIELDS {
+            return Err(format!("extension point {}: at most {MAX_FIELDS} fields", self.id));
+        }
+        for field in self.fields.keys() {
+            let ok = field.chars().next().is_some_and(|c| c.is_ascii_lowercase())
+                && field.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '_'))
+                && field.len() <= 64;
+            if !ok {
+                return Err(format!("extension point {}: invalid field name {field:?}", self.id));
+            }
+        }
+        for field in &self.required {
+            if !self.fields.contains_key(field) {
+                return Err(format!("extension point {}: required field {field:?} is not in `fields`", self.id));
+            }
+        }
+        Ok(())
+    }
+
+    /// Checks one contribution and returns it as JSON for the declaring plugin's code.
+    pub fn check(&self, value: &toml::Value) -> Result<serde_json::Value, String> {
+        let toml::Value::Table(table) = value else {
+            return Err("a contribution is a table".into());
+        };
+        for key in table.keys() {
+            if !self.fields.contains_key(key) {
+                let known: Vec<&str> = self.fields.keys().map(String::as_str).collect();
+                return Err(format!("unknown field {key:?} (this extension point has: {})", known.join(", ")));
+            }
+        }
+        for key in &self.required {
+            if !table.contains_key(key) {
+                return Err(format!("missing required field {key:?}"));
+            }
+        }
+        let mut out = serde_json::Map::new();
+        for (key, value) in table {
+            out.insert(key.clone(), convert(key, self.fields[key], value)?);
+        }
+        Ok(serde_json::Value::Object(out))
+    }
+}
+
+fn convert(key: &str, ty: FieldType, value: &toml::Value) -> Result<serde_json::Value, String> {
+    use serde_json::Value as J;
+    let wrong = |expected: &str| format!("field {key:?} must be {expected}");
+    match (ty, value) {
+        (FieldType::String, toml::Value::String(s)) => text(key, s).map(J::from),
+        (FieldType::Boolean, toml::Value::Boolean(b)) => Ok(J::from(*b)),
+        (FieldType::Integer, toml::Value::Integer(i)) => Ok(J::from(*i)),
+        (FieldType::Number, toml::Value::Integer(i)) => Ok(J::from(*i)),
+        (FieldType::Number, toml::Value::Float(f)) if f.is_finite() => Ok(J::from(*f)),
+        (FieldType::StringList, toml::Value::Array(items)) => {
+            if items.len() > MAX_LIST {
+                return Err(format!("field {key:?} has more than {MAX_LIST} items"));
+            }
+            items
+                .iter()
+                .map(|item| match item {
+                    toml::Value::String(s) => text(key, s).map(J::from),
+                    _ => Err(wrong("a list of strings")),
+                })
+                .collect::<Result<Vec<_>, _>>()
+                .map(J::Array)
+        }
+        (FieldType::String, _) => Err(wrong("a string")),
+        (FieldType::Boolean, _) => Err(wrong("true or false")),
+        (FieldType::Integer, _) => Err(wrong("an integer")),
+        (FieldType::Number, _) => Err(wrong("a number")),
+        (FieldType::StringList, _) => Err(wrong("a list of strings")),
+    }
+}
+
+fn text(key: &str, s: &str) -> Result<String, String> {
+    if s.len() > MAX_TEXT {
+        return Err(format!("field {key:?} is longer than {} KiB", MAX_TEXT >> 10));
+    }
+    Ok(s.to_owned())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn decl(src: &str) -> PointDecl {
+        toml::from_str(src).unwrap()
+    }
+
+    const COMPLETIONS: &str = r#"
+        id = "acme.base.completions"
+        description = "Extra completions"
+        required = ["label"]
+        fields = { label = "string", detail = "string", weight = "integer", scopes = "string-list" }
+    "#;
+
+    #[test]
+    fn the_id_is_namespaced_by_the_declaring_plugin() {
+        assert!(decl(COMPLETIONS).validate("acme.base").is_ok());
+        let err = decl(COMPLETIONS).validate("acme.other").unwrap_err();
+        assert!(err.contains("acme.other.<name>"), "{err}");
+        assert!(decl("id = \"acme.base.\"").validate("acme.base").is_err());
+        assert!(decl("id = \"acme.base.Bad Name\"").validate("acme.base").is_err());
+    }
+
+    #[test]
+    fn required_fields_must_be_declared() {
+        let err = decl("id = \"p.x\"\nrequired = [\"a\"]").validate("p").unwrap_err();
+        assert!(err.contains("required field \"a\""), "{err}");
+    }
+
+    #[test]
+    fn checks_a_contribution_and_converts_it_to_json() {
+        let point = decl(COMPLETIONS);
+        let contribution: toml::Value =
+            toml::from_str("label = \"ew.x\"\nweight = 3\nscopes = [\"xml\", \"java\"]").unwrap();
+        let json = point.check(&contribution).unwrap();
+        assert_eq!(json, serde_json::json!({"label": "ew.x", "weight": 3, "scopes": ["xml", "java"]}));
+    }
+
+    #[test]
+    fn refuses_what_the_point_does_not_declare() {
+        let point = decl(COMPLETIONS);
+        let check = |src: &str| point.check(&toml::from_str::<toml::Value>(src).unwrap()).unwrap_err();
+        assert!(check("detail = \"x\"").contains("missing required field \"label\""));
+        let err = check("label = \"a\"\nextra = 1");
+        assert!(err.contains("unknown field \"extra\"") && err.contains("label"), "{err}");
+        assert!(check("label = 1").contains("must be a string"));
+        assert!(check("label = \"a\"\nweight = \"3\"").contains("must be an integer"));
+        assert!(check("label = \"a\"\nscopes = [1]").contains("list of strings"));
+    }
+
+    #[test]
+    fn numbers_take_integers_and_floats() {
+        let point = decl("id = \"p.x\"\nfields = { ratio = \"number\" }");
+        assert!(point.check(&toml::from_str::<toml::Value>("ratio = 2").unwrap()).is_ok());
+        assert!(point.check(&toml::from_str::<toml::Value>("ratio = 0.5").unwrap()).is_ok());
+    }
+}

crates/ide-extension/src/registry.rs

@@ -1,6 +1,7 @@
 //! Extension points plus the contributions committed to them, accounted per plugin.
 
 use crate::capability::Capability;
+use crate::plugin_point::PointDecl;
 use crate::point::{Disposable, ExtensionPoint, Package, Placement, Prepared};
 use parking_lot::{Mutex, RwLock};
 use serde::{Deserialize, Serialize};
@@ -23,7 +24,7 @@ pub struct ContributionInfo {
 }
 
 struct Entry {
-    point: &'static str,
+    point: String,
     key: Option<String>,
     label: String,
     disposable: Disposable,
@@ -38,7 +39,7 @@ pub struct PreparedSet {
     pub files: Vec<PathBuf>,
     /// Declarations for extension points this host does not know (skipped).
     pub warnings: Vec<String>,
-    items: Vec<(&'static str, Prepared)>,
+    items: Vec<(String, Prepared)>,
 }
 
 impl PreparedSet {
@@ -61,11 +62,41 @@ impl std::fmt::Debug for PreparedSet {
     }
 }
 
+/// What one plugin contributed to an extension point another plugin declared.
+#[derive(Clone, Debug, PartialEq)]
+pub struct Contribution {
+    /// The contributing plugin.
+    pub plugin: String,
+    /// The declaration as JSON, checked against the point's fields.
+    pub data: serde_json::Value,
+}
+
+/// An extension point a plugin declared, with who contributes to it.
+#[derive(Clone, Debug, PartialEq)]
+pub struct DeclaredPoint {
+    pub owner: String,
+    pub decl: PointDecl,
+    /// Plugin ids, in commit order, once each.
+    pub contributors: Vec<String>,
+}
+
+#[derive(Default)]
+struct Dynamic {
+    points: BTreeMap<String, (String, PointDecl)>,
+    contributions: BTreeMap<String, Vec<Contribution>>,
+}
+
+/// Called with (point id, owner plugin) after contributions to a declared point changed.
+pub type ChangeListener = Arc<dyn Fn(&str, &str) + Send + Sync>;
+
 #[derive(Default)]
 pub struct ExtensionRegistry {
     points: RwLock<BTreeMap<&'static str, Arc<dyn ExtensionPoint>>>,
     /// plugin id → its contributions in commit order.
     entries: Mutex<BTreeMap<String, Vec<Entry>>>,
+    /// Points declared by plugins and what was contributed to them.
+    dynamic: Arc<Mutex<Dynamic>>,
+    listener: Arc<RwLock<Option<ChangeListener>>>,
 }
 
 impl ExtensionRegistry {
@@ -97,6 +128,111 @@ impl ExtensionRegistry {
         self.points.read().get(id).cloned()
     }
 
+    /// Registers the function told when contributions to a plugin-declared point change.
+    pub fn set_change_listener(&self, listener: ChangeListener) {
+        *self.listener.write() = Some(listener);
+    }
+
+    /// The plugin that declared `point`, while it is committed.
+    pub fn point_owner(&self, point: &str) -> Option<String> {
+        self.dynamic.lock().points.get(point).map(|(owner, _)| owner.clone())
+    }
+
+    /// What plugins contributed to `point`, in commit order. Empty unless a plugin declares it.
+    pub fn contributions_to(&self, point: &str) -> Vec<Contribution> {
+        let dynamic = self.dynamic.lock();
+        if !dynamic.points.contains_key(point) {
+            return Vec::new();
+        }
+        dynamic.contributions.get(point).cloned().unwrap_or_default()
+    }
+
+    /// The points `owner` declared, with their contributors.
+    pub fn declared_points(&self, owner: &str) -> Vec<DeclaredPoint> {
+        let dynamic = self.dynamic.lock();
+        dynamic
+            .points
+            .iter()
+            .filter(|(_, (o, _))| o == owner)
+            .map(|(id, (owner, decl))| {
+                let mut contributors: Vec<String> = Vec::new();
+                for c in dynamic.contributions.get(id).into_iter().flatten() {
+                    if !contributors.contains(&c.plugin) {
+                        contributors.push(c.plugin.clone());
+                    }
+                }
+                DeclaredPoint { owner: owner.clone(), decl: decl.clone(), contributors }
+            })
+            .collect()
+    }
+
+    /// Makes `pkg`'s `[[extension-points]]` known: they take effect with the set's commit.
+    fn prepare_declarations(&self, pkg: &Package) -> Vec<(String, Prepared)> {
+        pkg.manifest
+            .extension_points
+            .iter()
+            .map(|decl| {
+                let (dynamic, owner, decl) = (self.dynamic.clone(), pkg.id().to_owned(), decl.clone());
+                let id = decl.id.clone();
+                let prepared = Prepared::new(format!("Extension point {id}"), move || {
+                    let id = decl.id.clone();
+                    dynamic.lock().points.insert(id.clone(), (owner.clone(), decl));
+                    Ok(Disposable::new(move || {
+                        dynamic.lock().points.remove(&id);
+                    }))
+                })
+                .key(format!("extension-point:{id}"));
+                (id, prepared)
+            })
+            .collect()
+    }
+
+    /// Validates `pkg`'s contributions to a point some plugin declares, or `None`
+    /// when no plugin declares `point` (the caller then skips it as unknown).
+    fn prepare_contributions(&self, pkg: &Package, point: &str) -> Option<Result<Vec<Prepared>, String>> {
+        let declared = self.dynamic.lock().points.get(point).cloned();
+        let own =
+            pkg.manifest.extension_points.iter().find(|d| d.id == point).map(|d| (pkg.id().to_owned(), d.clone()));
+        let (owner, decl) = declared.or(own)?;
+        if owner != pkg.id() && !pkg.manifest.depends.iter().any(|d| d.id == owner) {
+            return Some(Err(format!("{point} is declared by {owner}: add it to [[depends]]")));
+        }
+        let listener = self.listener.clone();
+        let result = pkg
+            .manifest
+            .declarations(point)
+            .into_iter()
+            .enumerate()
+            .map(|(i, value)| {
+                let data = decl.check(&value).map_err(|e| format!("contributions[{i}]: {e}"))?;
+                let label = decl
+                    .required
+                    .first()
+                    .and_then(|field| data.get(field))
+                    .and_then(|v| v.as_str())
+                    .map_or_else(|| point.to_owned(), str::to_owned);
+                let contribution = Contribution { plugin: pkg.id().to_owned(), data };
+                let (dynamic, listener, point) = (self.dynamic.clone(), listener.clone(), point.to_owned());
+                Ok(Prepared::new(label, move || {
+                    dynamic.lock().contributions.entry(point.clone()).or_default().push(contribution.clone());
+                    notify(&dynamic, &listener, &point);
+                    Ok(Disposable::new(move || {
+                        {
+                            let mut guard = dynamic.lock();
+                            if let Some(list) = guard.contributions.get_mut(&point)
+                                && let Some(pos) = list.iter().position(|c| *c == contribution)
+                            {
+                                list.remove(pos);
+                            }
+                        }
+                        notify(&dynamic, &listener, &point);
+                    }))
+                }))
+            })
+            .collect();
+        Some(result)
+    }
+
     /// Validates every `contributes.<point>` declaration of `pkg`. Fails as a
     /// whole on the first invalid declaration; unknown points are skipped with
     /// a warning (forward compatibility).
@@ -108,9 +244,24 @@ impl ExtensionRegistry {
             warnings: Vec::new(),
             items: Vec::new(),
         };
+        // Declared points first: contributions to them (the plugin's own too) commit after.
+        set.items.extend(self.prepare_declarations(pkg));
         for point_id in pkg.manifest.contributes.keys() {
             let Some(point) = self.point(point_id) else {
-                let msg = format!("contributes.{point_id}: not supported by this version of the IDE; skipped");
+                if let Some(result) = self.prepare_contributions(pkg, point_id) {
+                    let prepared = result.map_err(|e| format!("contributes.{point_id}: {e}"))?;
+                    set.items.extend(prepared.into_iter().map(|p| (point_id.clone(), p)));
+                    continue;
+                }
+                // Point ids are `<owner id>.<name>`, so the dependency that owns it can be named.
+                let owner =
+                    pkg.manifest.depends.iter().find(|d| point_id.strip_prefix(&format!("{}.", d.id)).is_some());
+                let msg = match owner {
+                    Some(owner) => {
+                        format!("contributes.{point_id}: {} is not running, so this is skipped until it is", owner.id)
+                    }
+                    None => format!("contributes.{point_id}: not supported by this version of the IDE; skipped"),
+                };
                 tracing::warn!(plugin = %pkg.id(), "{msg}");
                 set.warnings.push(msg);
                 continue;
@@ -129,7 +280,7 @@ impl ExtensionRegistry {
                         set.files.push(f.clone());
                     }
                 }
-                set.items.push((point.id(), prepared));
+                set.items.push((point.id().to_owned(), prepared));
             }
         }
         if let Some(point) = self.point(LOCALES_POINT)
@@ -144,7 +295,7 @@ impl ExtensionRegistry {
                     set.files.push(f.clone());
                 }
             }
-            set.items.push((point.id(), prepared));
+            set.items.push((point.id().to_owned(), prepared));
         }
         Ok(set)
     }
@@ -201,7 +352,7 @@ impl ExtensionRegistry {
             .lock()
             .get(plugin)
             .map(|list| {
-                list.iter().map(|e| ContributionInfo { point: e.point.into(), label: e.label.clone() }).collect()
+                list.iter().map(|e| ContributionInfo { point: e.point.clone(), label: e.label.clone() }).collect()
             })
             .unwrap_or_default()
     }
@@ -217,6 +368,14 @@ impl ExtensionRegistry {
     }
 }
 
+fn notify(dynamic: &Mutex<Dynamic>, listener: &RwLock<Option<ChangeListener>>, point: &str) {
+    let owner = dynamic.lock().points.get(point).map(|(owner, _)| owner.clone());
+    let callback = listener.read().clone();
+    if let (Some(owner), Some(callback)) = (owner, callback) {
+        callback(point, &owner);
+    }
+}
+
 fn strip_prefix<'a>(e: &'a str, point: &str) -> &'a str {
     e.strip_prefix(&format!("contributes.{point}: ")).unwrap_or(e)
 }
@@ -310,6 +469,122 @@ mod tests {
         assert!(reg.contributions("p").is_empty());
     }
 
+    fn pkg_of(id: &str, body: &str) -> Package {
+        let src = format!("id = \"{id}\"\nname = \"N\"\nversion = \"1.0.0\"\nengines.openidea = \"^1.5\"\n{body}");
+        Package::new(Manifest::parse(&src).unwrap(), PathBuf::from("/nonexistent"))
+    }
+
+    const BASE: &str = r#"
+        [[extension-points]]
+        id = "acme.base.things"
+        required = ["name"]
+        fields = { name = "string", weight = "integer" }
+    "#;
+    const PLUGIN: &str =
+        "[[depends]]\nid = \"acme.base\"\n\n[[contributes.\"acme.base.things\"]]\nname = \"a\"\nweight = 2\n";
+
+    fn commit(reg: &ExtensionRegistry, pkg: &Package) {
+        reg.commit(reg.prepare(pkg).unwrap()).unwrap();
+    }
+
+    #[test]
+    fn a_plugin_declares_a_point_and_a_dependent_contributes_to_it() {
+        let reg = ExtensionRegistry::new();
+        commit(&reg, &pkg_of("acme.base", BASE));
+        assert_eq!(reg.point_owner("acme.base.things").as_deref(), Some("acme.base"));
+        assert!(reg.contributions_to("acme.base.things").is_empty());
+
+        commit(&reg, &pkg_of("acme.more", PLUGIN));
+        let got = reg.contributions_to("acme.base.things");
+        assert_eq!(got.len(), 1);
+        assert_eq!(got[0].plugin, "acme.more");
+        assert_eq!(got[0].data, serde_json::json!({"name": "a", "weight": 2}));
+        assert_eq!(
+            reg.contributions("acme.more")[0],
+            ContributionInfo { point: "acme.base.things".into(), label: "a".into() }
+        );
+        let declared = reg.declared_points("acme.base");
+        assert_eq!(declared.len(), 1);
+        assert_eq!(declared[0].contributors, ["acme.more"]);
+
+        assert!(reg.dispose_plugin("acme.more"));
+        assert!(reg.contributions_to("acme.base.things").is_empty());
+        assert!(reg.dispose_plugin("acme.base"));
+        assert_eq!(reg.point_owner("acme.base.things"), None);
+    }
+
+    #[test]
+    fn contributions_disappear_from_view_while_the_owner_is_gone() {
+        let reg = ExtensionRegistry::new();
+        commit(&reg, &pkg_of("acme.base", BASE));
+        commit(&reg, &pkg_of("acme.more", PLUGIN));
+        reg.dispose_plugin("acme.base");
+        assert!(reg.contributions_to("acme.base.things").is_empty(), "nobody may read a point that is not declared");
+        commit(&reg, &pkg_of("acme.base", BASE));
+        assert_eq!(reg.contributions_to("acme.base.things").len(), 1, "back with the owner");
+    }
+
+    #[test]
+    fn contributing_needs_a_dependency_on_the_owner() {
+        let reg = ExtensionRegistry::new();
+        commit(&reg, &pkg_of("acme.base", BASE));
+        let err =
+            reg.prepare(&pkg_of("acme.rogue", "[[contributes.\"acme.base.things\"]]\nname = \"x\"\n")).unwrap_err();
+        assert!(err.contains("acme.base") && err.contains("[[depends]]"), "{err}");
+    }
+
+    #[test]
+    fn a_contribution_is_checked_against_the_declared_fields() {
+        let reg = ExtensionRegistry::new();
+        commit(&reg, &pkg_of("acme.base", BASE));
+        let bad = "[[depends]]\nid = \"acme.base\"\n[[contributes.\"acme.base.things\"]]\nweight = 1\n";
+        let err = reg.prepare(&pkg_of("acme.more", bad)).unwrap_err();
+        assert_eq!(err, "contributes.acme.base.things: contributions[0]: missing required field \"name\"");
+    }
+
+    #[test]
+    fn a_point_nobody_declares_is_skipped_with_a_warning() {
+        let reg = ExtensionRegistry::new();
+        let set = reg.prepare(&pkg_of("acme.more", PLUGIN)).unwrap();
+        assert!(set.is_empty());
+        assert!(set.warnings[0].contains("acme.base.things"), "{:?}", set.warnings);
+    }
+
+    #[test]
+    fn a_missing_owner_is_named_instead_of_blaming_the_ide_version() {
+        let reg = ExtensionRegistry::new();
+        let set = reg.prepare(&pkg_of("acme.more", PLUGIN)).unwrap();
+        let warning = &set.warnings[0];
+        assert!(warning.contains("acme.base") && warning.contains("not running"), "{warning}");
+        assert!(!warning.contains("this version of the IDE"), "{warning}");
+
+        let unrelated = "[[contributes.\"acme.nobody.things\"]]\nname = \"x\"\n";
+        let set = reg.prepare(&pkg_of("acme.more", unrelated)).unwrap();
+        assert!(set.warnings[0].contains("this version of the IDE"), "{:?}", set.warnings);
+    }
+
+    #[test]
+    fn a_plugin_may_contribute_to_its_own_point() {
+        let reg = ExtensionRegistry::new();
+        let own = format!("{BASE}\n[[contributes.\"acme.base.things\"]]\nname = \"builtin\"\n");
+        commit(&reg, &pkg_of("acme.base", &own));
+        assert_eq!(reg.contributions_to("acme.base.things")[0].data["name"], "builtin");
+    }
+
+    #[test]
+    fn the_owner_hears_about_changes_to_its_point() {
+        let reg = ExtensionRegistry::new();
+        let heard: Arc<Mutex<Vec<(String, String)>>> = Arc::default();
+        let sink = heard.clone();
+        reg.set_change_listener(Arc::new(move |point, owner| sink.lock().push((point.into(), owner.into()))));
+        commit(&reg, &pkg_of("acme.base", BASE));
+        assert!(heard.lock().is_empty(), "declaring is not a contribution");
+        commit(&reg, &pkg_of("acme.more", PLUGIN));
+        reg.dispose_plugin("acme.more");
+        let expected = ("acme.base.things".to_owned(), "acme.base".to_owned());
+        assert_eq!(*heard.lock(), [expected.clone(), expected]);
+    }
+
     #[test]
     fn invalid_declarations_fail_prepare_and_unknown_points_warn() {
         let (reg, _) = setup();

crates/ide-extension/src/resolve.rs

@@ -0,0 +1,433 @@
+//! Which plugins can run, and in which order, given what they depend on.
+
+use semver::{Version, VersionReq};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use std::collections::{BTreeMap, BTreeSet};
+use std::fmt;
+
+/// `[[depends]]` of a manifest.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(deny_unknown_fields)]
+pub struct Dependency {
+    pub id: String,
+    /// Semver requirement on the dependency's version; none accepts any.
+    #[serde(default)]
+    pub version: Option<String>,
+    /// The plugin runs without it; when present it starts first.
+    #[serde(default)]
+    pub optional: bool,
+}
+
+impl Dependency {
+    /// `acme.base ^1.0`.
+    pub fn describe(&self) -> String {
+        match &self.version {
+            Some(v) => format!("{} {v}", self.id),
+            None => self.id.clone(),
+        }
+    }
+}
+
+/// A plugin as the resolver sees it.
+#[derive(Clone, Copy, Debug)]
+pub struct Node<'a> {
+    pub id: &'a str,
+    pub version: &'a str,
+    pub depends: &'a [Dependency],
+    /// Not switched off by the user.
+    pub enabled: bool,
+}
+
+/// Why an enabled plugin cannot run.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase", tag = "kind")]
+pub enum Blocked {
+    /// A required plugin is not installed.
+    Missing { requirement: String },
+    /// A required plugin is switched off.
+    Disabled { id: String },
+    /// A required plugin is installed in a version that does not satisfy the requirement.
+    Version { requirement: String, found: String },
+    /// A required plugin cannot run itself.
+    Dependency { id: String },
+    /// The plugin is part of a dependency cycle (`a → b → a`).
+    Cycle { ring: Vec<String> },
+}
+
+impl fmt::Display for Blocked {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Missing { requirement } => write!(f, "Requires {requirement}, which is not installed"),
+            Self::Disabled { id } => write!(f, "Requires {id}, which is disabled"),
+            Self::Version { requirement, found } => {
+                write!(f, "Requires {requirement}, but version {found} is installed")
+            }
+            Self::Dependency { id } => write!(f, "Requires {id}, which cannot run"),
+            Self::Cycle { ring } => write!(f, "Part of a dependency cycle: {}", ring.join(" → ")),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub struct Plan {
+    /// Plugins that can run, every plugin after the plugins it depends on.
+    pub order: Vec<String>,
+    /// Enabled plugins that cannot run. Disabled plugins are in neither list.
+    pub blocked: BTreeMap<String, Blocked>,
+}
+
+/// Decides, for every enabled plugin, whether its required plugins allow it to
+/// run and the order to start them in (the counterpart of IntelliJ's
+/// `PluginSetBuilder`: dependency graph, topological order, cycle report).
+pub fn plan(nodes: &[Node<'_>]) -> Plan {
+    let by_id: BTreeMap<&str, &Node<'_>> = nodes.iter().map(|n| (n.id, n)).collect();
+    let enabled: Vec<&Node<'_>> = by_id.values().copied().filter(|n| n.enabled).collect();
+    let mut blocked: BTreeMap<String, Blocked> = BTreeMap::new();
+
+    for node in &enabled {
+        for dep in node.depends.iter().filter(|d| !d.optional) {
+            if let Some(reason) = direct_reason(dep, by_id.get(dep.id.as_str()).copied()) {
+                blocked.entry(node.id.to_owned()).or_insert(reason);
+            }
+        }
+    }
+
+    // Cycles among plugins whose requirements are otherwise present.
+    let candidates: BTreeSet<&str> = enabled.iter().map(|n| n.id).filter(|id| !blocked.contains_key(*id)).collect();
+    let graph: Graph<'_> = candidates
+        .iter()
+        .map(|id| {
+            let deps = by_id[id].depends.iter().filter(|d| !d.optional).map(|d| d.id.as_str());
+            (*id, deps.filter(|d| candidates.contains(d)).collect())
+        })
+        .collect();
+    for component in components(&graph) {
+        let cyclic = component.len() > 1 || graph[component[0]].contains(&component[0]);
+        if cyclic {
+            let ring = ring_of(&component, &graph);
+            for id in component {
+                blocked.insert(id.to_owned(), Blocked::Cycle { ring: ring.clone() });
+            }
+        }
+    }
+
+    // A plugin that needs a blocked plugin is blocked too.
+    loop {
+        let mut changed = false;
+        for node in &enabled {
+            if blocked.contains_key(node.id) {
+                continue;
+            }
+            if let Some(dep) = node.depends.iter().find(|d| !d.optional && blocked.contains_key(&d.id)) {
+                blocked.insert(node.id.to_owned(), Blocked::Dependency { id: dep.id.clone() });
+                changed = true;
+            }
+        }
+        if !changed {
+            break;
+        }
+    }
+
+    let runnable: BTreeSet<&str> = enabled.iter().map(|n| n.id).filter(|id| !blocked.contains_key(*id)).collect();
+    Plan { order: topological(&runnable, &by_id), blocked }
+}
+
+/// Plugins that need `id`, directly or through other plugins, whether or not
+/// they are enabled. Optional dependencies do not count.
+pub fn dependents(nodes: &[Node<'_>], id: &str) -> Vec<String> {
+    let mut found: BTreeSet<String> = BTreeSet::new();
+    let mut frontier = vec![id.to_owned()];
+    while let Some(current) = frontier.pop() {
+        for node in nodes {
+            if node.depends.iter().any(|d| !d.optional && d.id == current) && found.insert(node.id.to_owned()) {
+                frontier.push(node.id.to_owned());
+            }
+        }
+    }
+    found.remove(id);
+    found.into_iter().collect()
+}
+
+/// How one dependency stands right now, for the plugin details page.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum DependencyState {
+    Satisfied,
+    Missing,
+    Disabled,
+    /// Installed, wrong version.
+    Version,
+    /// Installed and enabled, but cannot run itself.
+    Blocked,
+}
+
+pub fn dependency_state(dep: &Dependency, found: Option<&Node<'_>>, found_blocked: bool) -> DependencyState {
+    match direct_reason(dep, found) {
+        Some(Blocked::Missing { .. }) => DependencyState::Missing,
+        Some(Blocked::Disabled { .. }) => DependencyState::Disabled,
+        Some(Blocked::Version { .. }) => DependencyState::Version,
+        _ if found_blocked => DependencyState::Blocked,
+        _ => DependencyState::Satisfied,
+    }
+}
+
+fn direct_reason(dep: &Dependency, found: Option<&Node<'_>>) -> Option<Blocked> {
+    let Some(target) = found else {
+        return Some(Blocked::Missing { requirement: dep.describe() });
+    };
+    if !target.enabled {
+        return Some(Blocked::Disabled { id: dep.id.clone() });
+    }
+    let want = dep.version.as_deref()?;
+    let satisfied = VersionReq::parse(want)
+        .ok()
+        .zip(Version::parse(target.version).ok())
+        .is_some_and(|(req, have)| req.matches(&have));
+    (!satisfied).then(|| Blocked::Version { requirement: dep.describe(), found: target.version.to_owned() })
+}
+
+/// Plugin id → the plugin ids it requires.
+type Graph<'a> = BTreeMap<&'a str, Vec<&'a str>>;
+
+/// Strongly connected components (Tarjan) of `graph`.
+fn components<'a>(graph: &Graph<'a>) -> Vec<Vec<&'a str>> {
+    struct State<'a, 'g> {
+        index: usize,
+        stack: Vec<&'a str>,
+        info: BTreeMap<&'a str, (usize, usize, bool)>,
+        out: Vec<Vec<&'a str>>,
+        graph: &'g Graph<'a>,
+    }
+    fn visit<'a>(s: &mut State<'a, '_>, v: &'a str) {
+        s.info.insert(v, (s.index, s.index, true));
+        s.index += 1;
+        s.stack.push(v);
+        for &w in &s.graph[v] {
+            match s.info.get(w).copied() {
+                None => {
+                    visit(s, w);
+                    let low = s.info[w].1;
+                    let entry = s.info.get_mut(v).expect("visited");
+                    entry.1 = entry.1.min(low);
+                }
+                Some((index, _, true)) => {
+                    let entry = s.info.get_mut(v).expect("visited");
+                    entry.1 = entry.1.min(index);
+                }
+                Some(_) => {}
+            }
+        }
+        let (index, low, _) = s.info[v];
+        if index == low {
+            let mut component = Vec::new();
+            while let Some(w) = s.stack.pop() {
+                s.info.get_mut(w).expect("visited").2 = false;
+                component.push(w);
+                if w == v {
+                    break;
+                }
+            }
+            component.sort_unstable();
+            s.out.push(component);
+        }
+    }
+    let mut state = State { index: 0, stack: Vec::new(), info: BTreeMap::new(), out: Vec::new(), graph };
+    for &id in graph.keys() {
+        if !state.info.contains_key(id) {
+            visit(&mut state, id);
+        }
+    }
+    state.out
+}
+
+/// One cycle through `component`, from its smallest id back to it.
+fn ring_of(component: &[&str], graph: &Graph<'_>) -> Vec<String> {
+    let start = component[0];
+    let mut ring = vec![start.to_owned()];
+    let mut current = start;
+    let mut seen: BTreeSet<&str> = BTreeSet::from([start]);
+    loop {
+        let mut next: Vec<&str> = graph[current].iter().copied().filter(|d| component.contains(d)).collect();
+        next.sort_unstable();
+        // Prefer closing the ring; otherwise take the smallest unseen member.
+        let step =
+            if next.contains(&start) { start } else { *next.iter().find(|d| !seen.contains(**d)).unwrap_or(&start) };
+        ring.push(step.to_owned());
+        if step == start {
+            return ring;
+        }
+        seen.insert(step);
+        current = step;
+    }
+}
+
+/// Kahn's algorithm over the runnable plugins; ties break by id. Optional
+/// dependencies order too, but never block: leftovers (an optional edge
+/// closing a loop) are appended by id.
+fn topological(runnable: &BTreeSet<&str>, by_id: &BTreeMap<&str, &Node<'_>>) -> Vec<String> {
+    let mut waiting: BTreeMap<&str, BTreeSet<&str>> = runnable
+        .iter()
+        .map(|id| {
+            let deps = by_id[id].depends.iter().map(|d| d.id.as_str()).filter(|d| runnable.contains(d) && d != id);
+            (*id, deps.collect())
+        })
+        .collect();
+    let mut order: Vec<String> = Vec::with_capacity(runnable.len());
+    while let Some(next) = waiting.iter().find(|(_, deps)| deps.is_empty()).map(|(id, _)| *id) {
+        waiting.remove(next);
+        for deps in waiting.values_mut() {
+            deps.remove(next);
+        }
+        order.push(next.to_owned());
+    }
+    order.extend(waiting.keys().map(|id| (*id).to_owned()));
+    order
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn dep(id: &str) -> Dependency {
+        Dependency { id: id.into(), version: None, optional: false }
+    }
+
+    fn dep_v(id: &str, version: &str) -> Dependency {
+        Dependency { id: id.into(), version: Some(version.into()), optional: false }
+    }
+
+    fn optional(id: &str) -> Dependency {
+        Dependency { id: id.into(), version: None, optional: true }
+    }
+
+    fn node<'a>(id: &'a str, depends: &'a [Dependency]) -> Node<'a> {
+        Node { id, version: "1.0.0", depends, enabled: true }
+    }
+
+    #[test]
+    fn dependencies_start_first_whatever_the_ids_sort_like() {
+        let (a, z) = ([dep("z.base")], []);
+        let plan = plan(&[node("a.app", &a), node("z.base", &z)]);
+        assert_eq!(plan.order, ["z.base", "a.app"]);
+        assert!(plan.blocked.is_empty());
+    }
+
+    #[test]
+    fn independent_plugins_keep_id_order() {
+        let plan = plan(&[node("b", &[]), node("a", &[]), node("c", &[])]);
+        assert_eq!(plan.order, ["a", "b", "c"]);
+    }
+
+    #[test]
+    fn a_missing_requirement_blocks_with_the_requirement_text() {
+        let needs = [dep_v("acme.base", "^1.0")];
+        let plan = plan(&[node("acme.app", &needs)]);
+        assert!(plan.order.is_empty());
+        assert_eq!(plan.blocked["acme.app"], Blocked::Missing { requirement: "acme.base ^1.0".into() });
+        assert_eq!(plan.blocked["acme.app"].to_string(), "Requires acme.base ^1.0, which is not installed");
+    }
+
+    #[test]
+    fn a_disabled_requirement_blocks_but_the_disabled_plugin_itself_is_not_blocked() {
+        let needs = [dep("acme.base")];
+        let mut base = node("acme.base", &[]);
+        base.enabled = false;
+        let plan = plan(&[base, node("acme.app", &needs)]);
+        assert_eq!(plan.blocked["acme.app"], Blocked::Disabled { id: "acme.base".into() });
+        assert!(!plan.blocked.contains_key("acme.base"));
+        assert!(plan.order.is_empty());
+    }
+
+    #[test]
+    fn the_installed_version_must_satisfy_the_requirement() {
+        let needs = [dep_v("acme.base", "^0.2")];
+        let mut base = node("acme.base", &[]);
+        base.version = "0.3.0";
+        let plan_bad = plan(&[base, node("acme.app", &needs)]);
+        assert_eq!(
+            plan_bad.blocked["acme.app"],
+            Blocked::Version { requirement: "acme.base ^0.2".into(), found: "0.3.0".into() }
+        );
+        assert_eq!(plan_bad.blocked["acme.app"].to_string(), "Requires acme.base ^0.2, but version 0.3.0 is installed");
+
+        base.version = "0.2.7";
+        let plan_ok = plan(&[base, node("acme.app", &needs)]);
+        assert!(plan_ok.blocked.is_empty());
+        assert_eq!(plan_ok.order, ["acme.base", "acme.app"]);
+    }
+
+    #[test]
+    fn blocking_propagates_to_everything_downstream() {
+        let (b, c) = ([dep("a")], [dep("b")]);
+        let plan = plan(&[node("b", &b), node("c", &c)]);
+        assert_eq!(plan.blocked["b"], Blocked::Missing { requirement: "a".into() });
+        assert_eq!(plan.blocked["c"], Blocked::Dependency { id: "b".into() });
+        assert!(plan.order.is_empty());
+    }
+
+    #[test]
+    fn an_optional_requirement_never_blocks_but_orders_when_present() {
+        let app = [optional("acme.extra")];
+        let alone = plan(&[node("acme.app", &app)]);
+        assert_eq!(alone.order, ["acme.app"]);
+        assert!(alone.blocked.is_empty());
+
+        let with = plan(&[node("acme.app", &app), node("acme.extra", &[])]);
+        assert_eq!(with.order, ["acme.extra", "acme.app"]);
+
+        let mut off = node("acme.extra", &[]);
+        off.enabled = false;
+        let disabled = plan(&[node("acme.app", &app), off]);
+        assert_eq!(disabled.order, ["acme.app"]);
+        assert!(disabled.blocked.is_empty());
+    }
+
+    #[test]
+    fn a_cycle_blocks_its_members_and_names_the_ring() {
+        let (a, b, d) = ([dep("b")], [dep("a")], [dep("a")]);
+        let plan = plan(&[node("a", &a), node("b", &b), node("d", &d)]);
+        let ring = Blocked::Cycle { ring: vec!["a".into(), "b".into(), "a".into()] };
+        assert_eq!(plan.blocked["a"], ring);
+        assert_eq!(plan.blocked["b"], ring);
+        assert_eq!(ring.to_string(), "Part of a dependency cycle: a → b → a");
+        assert_eq!(plan.blocked["d"], Blocked::Dependency { id: "a".into() });
+        assert!(plan.order.is_empty());
+    }
+
+    #[test]
+    fn a_plugin_requiring_itself_is_a_cycle() {
+        let a = [dep("a")];
+        let plan = plan(&[node("a", &a)]);
+        assert_eq!(plan.blocked["a"], Blocked::Cycle { ring: vec!["a".into(), "a".into()] });
+    }
+
+    #[test]
+    fn an_optional_loop_does_not_block_and_still_yields_every_plugin() {
+        let (a, b) = ([optional("b")], [optional("a")]);
+        let plan = plan(&[node("a", &a), node("b", &b)]);
+        assert!(plan.blocked.is_empty());
+        assert_eq!(plan.order.len(), 2);
+    }
+
+    #[test]
+    fn dependents_are_transitive_and_ignore_optional_edges() {
+        let (b, c, d) = ([dep("a")], [dep("b")], [optional("a")]);
+        let nodes = [node("a", &[]), node("b", &b), node("c", &c), node("d", &d)];
+        assert_eq!(dependents(&nodes, "a"), ["b", "c"]);
+        assert_eq!(dependents(&nodes, "c"), Vec::<String>::new());
+    }
+
+    #[test]
+    fn dependency_state_tells_the_details_page_what_to_say() {
+        let want = dep_v("base", "^1.0");
+        assert_eq!(dependency_state(&want, None, false), DependencyState::Missing);
+        let mut base = node("base", &[]);
+        assert_eq!(dependency_state(&want, Some(&base), false), DependencyState::Satisfied);
+        assert_eq!(dependency_state(&want, Some(&base), true), DependencyState::Blocked);
+        base.version = "2.0.0";
+        assert_eq!(dependency_state(&want, Some(&base), false), DependencyState::Version);
+        base.enabled = false;
+        assert_eq!(dependency_state(&want, Some(&base), false), DependencyState::Disabled);
+    }
+}

crates/ide-github/src/lib.rs

@@ -102,6 +102,14 @@ fn parse<T>(r: serde_json::Result<T>) -> IdeResult<T> {
     r.map_err(|e| IdeError::new(ide_core::error::ErrorKind::Protocol, format!("unexpected gh output: {e}")))
 }
 
+/// The repository of `root`, free to execute: the host runs the `gh_*` commands only in a
+/// trusted project.
+fn trusted_repo(root: &Path) -> IdeResult<Repo> {
+    let repo = Repo::discover(root)?.ok_or_else(|| IdeError::invalid("not a git repository"))?;
+    repo.set_execution_allowed(true);
+    Ok(repo)
+}
+
 /// Whether gh is installed and signed in, and which GitHub repository `root` maps to.
 pub fn availability(root: &Path) -> GhAvailability {
     if gh_executable().is_none() {
@@ -233,7 +241,7 @@ pub fn create(
         return Err(IdeError::invalid("choose a base branch"));
     }
     if req.push {
-        let repo = Repo::discover(root)?.ok_or_else(|| IdeError::invalid("not a git repository"))?;
+        let repo = trusted_repo(root)?;
         repo.push(false, true, cancel, on_output)?;
     }
     let mut args = vec!["pr", "create", "--title", req.title.trim(), "--body", &req.body, "--base", req.base.trim()];
@@ -354,7 +362,7 @@ pub fn prepare_diff(
     cancel: &CancellationToken,
     on_output: &dyn Fn(String),
 ) -> IdeResult<PrDiffRevisions> {
-    let repo = Repo::discover(root)?.ok_or_else(|| IdeError::invalid("not a git repository"))?;
+    let repo = trusted_repo(root)?;
     if !repo.has_commit(head_oid) || !repo.has_commit(base_oid) {
         let remotes = repo.remotes()?;
         let remote = remote_for(&remotes, name_with_owner)

crates/ide-heap/Cargo.toml

@@ -0,0 +1,28 @@
+[package]
+name = "ide-heap"
+description = "HotSpot .hprof parser and heap-snapshot analysis for the debugger's JVM Memory view"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+
+[dependencies]
+ide-core.workspace = true
+memmap2.workspace = true
+serde.workspace = true
+serde_json.workspace = true
+specta.workspace = true
+thiserror.workspace = true
+tracing.workspace = true
+uuid.workspace = true
+
+[target.'cfg(unix)'.dependencies]
+libc = "0.2"
+
+[dev-dependencies]
+criterion = { version = "0.5", default-features = false }
+proptest.workspace = true
+tempfile.workspace = true
+
+[[bench]]
+name = "heap"
+harness = false

crates/ide-heap/benches/heap.rs

@@ -0,0 +1,100 @@
+//! `cargo bench -p ide-heap`: whole-dump analysis and the dominator tree at a million objects.
+
+use criterion::{Criterion, black_box, criterion_group, criterion_main};
+use ide_core::CancellationToken;
+use ide_heap::testing::{MiniHeap, XorShift};
+use ide_heap::{AnalyzeOptions, BasicType, HeapError, HeapPhase, HeapRootKind, Store, analyze, dominators};
+
+const CHAINS: u64 = 100_000;
+const CHAIN_LEN: u64 = 5;
+const NODES: u64 = CHAINS * CHAIN_LEN;
+/// Every object takes one slot: node `k` at slot `2k`, its payload at `2k + 1`.
+const BASE: u64 = 0x1_0000_0000;
+const SLOT: u64 = 0x20;
+
+fn node_addr(k: u64) -> u64 {
+    BASE + 2 * k * SLOT
+}
+
+fn payload_addr(k: u64) -> u64 {
+    node_addr(k) + SLOT
+}
+
+/// 100k rooted chains of five `Node { next, payload }`, each node with its own `byte[16]`. Every
+/// seventh node points at the payload of the same position in the next chain instead, so that
+/// payload has two owners and its own one is garbage: 1M objects in all.
+fn million_objects() -> MiniHeap {
+    let mut heap = MiniHeap::new();
+    heap.class("Node", Some("java.lang.Object"), &[("next", BasicType::Object), ("payload", BasicType::Object)]);
+    for k in 0..NODES {
+        let next = if (k + 1) % CHAIN_LEN == 0 { 0 } else { node_addr(k + 1) };
+        let payload = if k % 7 == 0 { payload_addr((k + CHAIN_LEN) % NODES) } else { payload_addr(k) };
+        heap.object(node_addr(k), "Node", &[("next", next), ("payload", payload)]);
+        heap.prim(payload_addr(k), BasicType::Byte, 16);
+        if k % CHAIN_LEN == 0 {
+            heap.root(HeapRootKind::JniGlobal, node_addr(k));
+        }
+    }
+    heap
+}
+
+/// CSR of a random tree on `nodes` nodes rooted at 0 plus `extra` random edges, targets of each
+/// node in scrambled order.
+fn random_graph(nodes: u32, extra: u32, seed: u64) -> (Vec<u32>, Vec<u32>) {
+    let mut rng = XorShift::new(seed);
+    let mut edges: Vec<(u32, u32)> = (1..nodes).map(|v| (rng.below(v), v)).collect();
+    edges.extend((0..extra).map(|_| (rng.below(nodes), rng.below(nodes))));
+    for i in (1..edges.len()).rev() {
+        edges.swap(i, rng.below(i as u32 + 1) as usize);
+    }
+    let mut start = vec![0u32; nodes as usize + 1];
+    for &(from, _) in &edges {
+        start[from as usize + 1] += 1;
+    }
+    for v in 0..nodes as usize {
+        start[v + 1] += start[v];
+    }
+    let mut cursor = start.clone();
+    let mut out = vec![0u32; edges.len()];
+    for &(from, to) in &edges {
+        out[cursor[from as usize] as usize] = to;
+        cursor[from as usize] += 1;
+    }
+    (start, out)
+}
+
+fn no_progress(_: HeapPhase, _: u64, _: u64) -> Result<(), HeapError> {
+    Ok(())
+}
+
+fn bench(c: &mut Criterion) {
+    let dir = tempfile::tempdir().expect("temp dir");
+    let hprof = dir.path().join("dump.hprof");
+    million_objects().write_to(&hprof);
+    let (start, out) = random_graph(1_000_000, 500_000, 0x5EED_D0D0);
+    let cancel = CancellationToken::new();
+    let opts = AnalyzeOptions { in_memory: true, ..AnalyzeOptions::default() };
+    let summary = analyze(&hprof, dir.path(), opts, &no_progress, &cancel).expect("analyze").summary;
+    assert_eq!(summary.objects, 2 * NODES, "{summary:?}");
+    assert_eq!(summary.unreachable_objects, NODES.div_ceil(7), "{summary:?}");
+
+    let mut g = c.benchmark_group("heap");
+    g.sample_size(10);
+    g.bench_function("index_1m_objects", |b| {
+        b.iter(|| {
+            let opts = AnalyzeOptions { in_memory: true, ..AnalyzeOptions::default() };
+            let index = analyze(&hprof, dir.path(), opts, &no_progress, &cancel).expect("analyze");
+            black_box(index.summary.objects)
+        })
+    });
+    g.bench_function("dominators_1m_random", |b| {
+        b.iter(|| {
+            let d = dominators(&start, &out, 0, &Store::Ram, &no_progress, &cancel).expect("dominators");
+            black_box(d.reachable)
+        })
+    });
+    g.finish();
+}
+
+criterion_group!(benches, bench);
+criterion_main!(benches);

crates/ide-heap/src/analysis.rs

@@ -0,0 +1,202 @@
+//! Ties the passes together: graph, dominators, shallow and retained sizes, the class table and
+//! paths to GC roots, into a [`HeapIndex`].
+
+mod classes;
+mod paths;
+mod retained;
+
+use std::collections::HashMap;
+use std::fs::File;
+use std::path::Path;
+use std::time::Instant;
+
+use ide_core::CancellationToken;
+use memmap2::Mmap;
+
+use crate::column::Store;
+use crate::dominators::{Dominators, dominators};
+use crate::error::HeapError;
+use crate::files::INDEX_FILES;
+use crate::graph::{HeapGraph, build_graph};
+use crate::index::{HeapIndex, HeapSummary, write_summary};
+use crate::progress::{CHECK_EVERY, HeapPhase, Progress};
+use crate::shallow::{HistogramEntry, ShallowModel, VmLayout};
+
+#[derive(Clone, Debug, Default)]
+pub struct AnalyzeOptions {
+    /// The JVM's class histogram from the same stop as the dump.
+    pub histogram: Option<Vec<HistogramEntry>>,
+    /// `VM.flags` output of the JVM that wrote the dump.
+    pub vm_flags: Option<String>,
+    pub java_major: Option<u32>,
+    /// Keep every array in RAM and write nothing to `index_dir`.
+    pub in_memory: bool,
+}
+
+/// Analyzes the dump at `hprof`, writing the index columns and `summary.json` into `index_dir`
+/// (which must exist and may hold the dump itself). `progress` gets every [`HeapPhase`] in order;
+/// an `Err` from it, a cancel or any other error removes every index file from `index_dir` and
+/// leaves the rest of the directory alone.
+pub fn analyze(
+    hprof: &Path,
+    index_dir: &Path,
+    opts: AnalyzeOptions,
+    progress: &dyn Fn(HeapPhase, u64, u64) -> Result<(), HeapError>,
+    cancel: &CancellationToken,
+) -> Result<HeapIndex, HeapError> {
+    let store = if opts.in_memory { Store::Ram } else { Store::Dir(index_dir.to_path_buf()) };
+    let result = run(hprof, &store, opts, progress, cancel);
+    // `run` has dropped every column by now: Windows cannot delete a mapped file.
+    if result.is_err() && !matches!(store, Store::Ram) {
+        remove_index_files(index_dir);
+    }
+    result
+}
+
+fn run(
+    hprof: &Path,
+    store: &Store,
+    opts: AnalyzeOptions,
+    report: &dyn Fn(HeapPhase, u64, u64) -> Result<(), HeapError>,
+    cancel: &CancellationToken,
+) -> Result<HeapIndex, HeapError> {
+    let started = Instant::now();
+    let progress = Progress::new(report, cancel);
+    let file = File::open(hprof)?;
+    // SAFETY: nothing writes the dump while it is analyzed or viewed: a capture finishes writing
+    // it before analysis and deletes it only with the snapshot that holds this index.
+    let dump = unsafe { Mmap::map(&file)? };
+    let graph = build_graph(&dump, store, report, cancel)?;
+    let Dominators { idom, preorder, .. } =
+        dominators(&graph.out_start, &graph.out, graph.root, store, report, cancel)?;
+
+    let nodes = u64::from(graph.root) + 1;
+    // Seven walks over the nodes, roughly: sizes, retained, child counts, child sorting, class
+    // counts and the tree walk, which visits every node twice.
+    let mut meter = Meter::start(&progress, HeapPhase::Retained, 7 * nodes)?;
+    let layout = VmLayout::from_vm_flags(opts.vm_flags.as_deref().unwrap_or(""), opts.java_major);
+    let model = ShallowModel::new(&graph, layout, opts.histogram.as_deref(), cancel)?;
+    let (shallow8, retained) = retained::sizes(&graph, &model, &idom, &preorder, store, &mut meter)?;
+    drop(preorder);
+    let (kids_start, kids) = retained::children(&idom, &retained, graph.root, store, &mut meter)?;
+    let tree = retained::Tree { idom, shallow8, retained, kids_start, kids };
+    let (classes, totals) = classes::table(&graph, &tree, store, &mut meter)?;
+    meter.finish()?;
+
+    let mut meter = Meter::start(&progress, HeapPhase::Paths, nodes + graph.out.len() as u64)?;
+    let gc_parent = paths::gc_parents(&graph, store, &mut meter)?;
+    meter.finish()?;
+
+    progress.report(HeapPhase::Saving, 0, 1)?;
+    let HeapGraph {
+        ids,
+        types,
+        offsets,
+        roots,
+        classes: class_info,
+        class_slot,
+        thread_objects,
+        weak_edges_skipped,
+        id_size,
+        ..
+    } = graph;
+    let summary = HeapSummary {
+        objects: totals.reachable_objects + totals.unreachable_objects,
+        reachable_objects: totals.reachable_objects,
+        reachable_bytes: totals.reachable_bytes,
+        unreachable_objects: totals.unreachable_objects,
+        unreachable_bytes: totals.unreachable_bytes,
+        classes: class_info.iter().filter(|c| c.id != 0).count() as u32,
+        weak_edges_skipped,
+        size_source: model.source,
+        analysis_ms: u32::try_from(started.elapsed().as_millis()).unwrap_or(u32::MAX),
+    };
+    if let Store::Dir(dir) = store {
+        write_summary(dir, &summary)?;
+    }
+    let mut root_kinds = HashMap::with_capacity(roots.len());
+    for (object, kind, serial) in roots {
+        root_kinds.entry(object).or_insert((kind, serial));
+    }
+    progress.report(HeapPhase::Saving, 1, 1)?;
+
+    let retained::Tree { idom, shallow8, retained, kids_start, kids } = tree;
+    Ok(HeapIndex {
+        hprof: dump,
+        ids,
+        types,
+        offsets,
+        shallow8,
+        retained,
+        idom,
+        kids_start,
+        kids,
+        gc_parent,
+        classes,
+        class_info,
+        class_slot,
+        roots: root_kinds,
+        thread_objects,
+        id_size,
+        summary,
+    })
+}
+
+/// Removes what an analysis may have written; a file that is not there is fine.
+fn remove_index_files(dir: &Path) {
+    for name in INDEX_FILES {
+        let path = dir.join(name);
+        if let Err(err) = std::fs::remove_file(&path)
+            && err.kind() != std::io::ErrorKind::NotFound
+        {
+            tracing::warn!("could not remove {}: {err}", path.display());
+        }
+    }
+}
+
+/// Steps of one phase: reports progress every [`CHECK_EVERY`] steps, and each loop looks at the
+/// token before its first step.
+pub(super) struct Meter<'a> {
+    progress: &'a Progress<'a>,
+    phase: HeapPhase,
+    /// An estimate; `done` is clamped to it.
+    total: u64,
+    done: u64,
+    next_report: u64,
+}
+
+impl<'a> Meter<'a> {
+    fn start(progress: &'a Progress<'a>, phase: HeapPhase, total: u64) -> Result<Self, HeapError> {
+        progress.report(phase, 0, total)?;
+        Ok(Self { progress, phase, total, done: 0, next_report: CHECK_EVERY })
+    }
+
+    pub(super) fn begin_loop(&self) -> Result<(), HeapError> {
+        self.progress.check()
+    }
+
+    pub(super) fn token(&self) -> &'a CancellationToken {
+        self.progress.token()
+    }
+
+    #[inline]
+    pub(super) fn tick(&mut self) -> Result<(), HeapError> {
+        self.advance(1)
+    }
+
+    pub(super) fn advance(&mut self, steps: u64) -> Result<(), HeapError> {
+        self.done += steps;
+        if self.done < self.next_report {
+            return Ok(());
+        }
+        self.next_report = self.done + CHECK_EVERY;
+        self.progress.report(self.phase, self.done.min(self.total), self.total)
+    }
+
+    fn finish(self) -> Result<(), HeapError> {
+        self.progress.report(self.phase, self.total, self.total)
+    }
+}
+
+#[cfg(test)]
+mod tests;

crates/ide-heap/src/analysis/classes.rs

@@ -0,0 +1,117 @@
+//! The class table: counts and shallow sizes per type slot, retained sizes per type from a walk of
+//! the dominator tree, and the reachable / unreachable totals of the summary.
+
+use super::Meter;
+use super::retained::Tree;
+use crate::column::{NONE, Store};
+use crate::error::HeapError;
+use crate::graph::{HeapGraph, PRIM_SLOTS};
+use crate::hprof::BasicType;
+use crate::index::ClassStat;
+use crate::names::display_name;
+
+/// Instances and arrays only: class objects are left out.
+#[derive(Default)]
+pub(super) struct Totals {
+    pub(super) reachable_objects: u64,
+    pub(super) reachable_bytes: u64,
+    pub(super) unreachable_objects: u64,
+    pub(super) unreachable_bytes: u64,
+}
+
+pub(super) fn table(
+    graph: &HeapGraph,
+    tree: &Tree,
+    store: &Store,
+    meter: &mut Meter,
+) -> Result<(Vec<ClassStat>, Totals), HeapError> {
+    let slots = graph.classes.len() + PRIM_SLOTS as usize;
+    let mut classes: Vec<ClassStat> = (0..slots as u32)
+        .map(|slot| ClassStat { name: slot_name(graph, slot), count: 0, shallow: 0, retained: 0, unreachable_count: 0 })
+        .collect();
+    let mut totals = Totals::default();
+    meter.begin_loop()?;
+    for v in 0..graph.root as usize {
+        meter.tick()?;
+        let slot = graph.types[v];
+        let bytes = u64::from(tree.shallow8[v]) * 8;
+        let stat = &mut classes[slot as usize];
+        let instance = slot != graph.class_slot;
+        if tree.idom[v] == NONE {
+            stat.unreachable_count += 1;
+            if instance {
+                totals.unreachable_objects += 1;
+                totals.unreachable_bytes += bytes;
+            }
+        } else {
+            stat.count += 1;
+            stat.shallow += bytes;
+            if instance {
+                totals.reachable_objects += 1;
+                totals.reachable_bytes += bytes;
+            }
+        }
+    }
+    retained_by_type(graph, tree, &mut classes, store, meter)?;
+    Ok((classes, totals))
+}
+
+/// Adds to each type the retained size of its instances that have no instance of the same type
+/// above them in the dominator tree. The walk keeps no stack: it goes up through `idom` and
+/// resumes a node's children from `cursor`, while `active[t]` counts the instances of type `t` on
+/// the path from the root.
+fn retained_by_type(
+    graph: &HeapGraph,
+    tree: &Tree,
+    classes: &mut [ClassStat],
+    store: &Store,
+    meter: &mut Meter,
+) -> Result<(), HeapError> {
+    let root = graph.root;
+    let mut cursor = store.scratch::<u32>(root as usize + 1, 0)?;
+    let mut active = vec![0u32; classes.len()];
+    cursor[root as usize] = tree.kids_start[root as usize];
+    let mut v = root;
+    meter.begin_loop()?;
+    loop {
+        meter.tick()?;
+        let next = cursor[v as usize];
+        if next < tree.kids_start[v as usize + 1] {
+            cursor[v as usize] = next + 1;
+            let child = tree.kids[next as usize];
+            let slot = graph.types[child as usize] as usize;
+            if active[slot] == 0 {
+                classes[slot].retained += tree.retained[child as usize];
+            }
+            active[slot] += 1;
+            cursor[child as usize] = tree.kids_start[child as usize];
+            v = child;
+        } else if v == root {
+            return Ok(());
+        } else {
+            active[graph.types[v as usize] as usize] -= 1;
+            v = tree.idom[v as usize];
+        }
+    }
+}
+
+fn slot_name(graph: &HeapGraph, slot: u32) -> String {
+    match graph.classes.get(slot as usize) {
+        Some(class) => display_name(&class.name),
+        None => graph.prim_type(slot).map_or_else(String::new, |ty| prim_array_name(ty).to_owned()),
+    }
+}
+
+fn prim_array_name(ty: BasicType) -> &'static str {
+    match ty {
+        BasicType::Object => "java.lang.Object[]",
+        BasicType::Boolean => "boolean[]",
+        BasicType::Char => "char[]",
+        BasicType::Float => "float[]",
+        BasicType::Double => "double[]",
+        BasicType::Byte => "byte[]",
+        BasicType::Short => "short[]",
+        BasicType::Int => "int[]",
+        BasicType::Long => "long[]",
+    }
+}