fix(themes): add the shell command token to the theme template and docs

#3458 added --syn-shell-command without setting it in the Harbor Night scheme (the template new themes start from) or regenerating plugins/themes.md, so scripts/theme/theme.test.ts failed. Imported IntelliJ schemes map BASH.EXTERNAL_COMMAND to it.
fix(editor): highlight shell commands, function names and local from the grammar (#3458 )
2026-11-15 14:15:39 +02:00 · 2026-11-15 08:23:08 +08:00 · 2026-11-15 05:10:11 +08:00 · 2026-11-15 04:32:12 +08:00 · 2026-11-15 04:11:35 +08:00 · 2026-11-15 04:10:44 +08:00
@@ -7,7 +7,7 @@ BASEDPYRIGHT=1.40.2
 RUFF=0.17.3
 GOPLS=v0.24.0
 JDTLS=1.63.0-202610191322
-KOTLIN_LSP=263.7084.0
+KOTLIN_LSP=271.2085.0
 GRADLE=8.14.3
 INTELEPHENSE=1.18.5
 # The JDK projects compile against (JAVA_HOME): library navigation opens its sources.
@@ -119,7 +119,7 @@ jobs:
      - 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'
-        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact maven_sync jdk
+        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact maven_sync jdk maven_launch_classpath_uses_the_runner_jdk_classifier
      - if: matrix.language == 'kotlin'
        run: cargo test --locked -p ide-host --test project_smoke -- --ignored --exact gradle_sync
      - if: matrix.language == 'python'
@@ -4144,8 +4144,9 @@ checksum = "3d3067d79b975e8844ca9eb072e16b31c3c1c36928edf9c6789548c524d0d954"

 [[package]]
 name = "ide-agent"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
+ "blake3",
 "dunce",
 "encoding_rs",
 "ide-core",
@@ -4168,7 +4169,7 @@ dependencies = [

 [[package]]
 name = "ide-analysis"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ast-grep-core",
 "ide-core",
@@ -4182,7 +4183,7 @@ dependencies = [

 [[package]]
 name = "ide-android"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "serde",
@@ -4193,7 +4194,7 @@ dependencies = [

 [[package]]
 name = "ide-build"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "chardetng",
@@ -4211,7 +4212,7 @@ dependencies = [

 [[package]]
 name = "ide-cli"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dirs 6.0.0",
 "serde",
@@ -4225,7 +4226,7 @@ dependencies = [

 [[package]]
 name = "ide-clipboard"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "gtk",
 "objc2 0.6.5",
@@ -4235,7 +4236,7 @@ dependencies = [

 [[package]]
 name = "ide-core"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4252,7 +4253,7 @@ dependencies = [

 [[package]]
 name = "ide-coverage"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-run",
@@ -4266,8 +4267,9 @@ dependencies = [

 [[package]]
 name = "ide-dap"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
+ "base64 0.22.1",
 "futures",
 "ide-core",
 "ide-heap",
@@ -4286,6 +4288,7 @@ dependencies = [
 "specta",
 "tempfile",
 "tokio",
+ "tokio-tungstenite",
 "tracing",
 "tracing-subscriber",
 "windows-sys 0.61.2",
@@ -4293,7 +4296,7 @@ dependencies = [

 [[package]]
 name = "ide-db"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "base64 0.22.1",
 "bb8",
@@ -4329,7 +4332,7 @@ dependencies = [

 [[package]]
 name = "ide-docker"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "serde",
@@ -4342,7 +4345,7 @@ dependencies = [

 [[package]]
 name = "ide-extension"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "base64 0.22.1",
 "blake3",
@@ -4363,7 +4366,7 @@ dependencies = [

 [[package]]
 name = "ide-fonts"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "objc2-core-foundation",
 "objc2-core-text",
@@ -4375,7 +4378,7 @@ dependencies = [

 [[package]]
 name = "ide-github"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-vcs",
@@ -4388,7 +4391,7 @@ dependencies = [

 [[package]]
 name = "ide-heap"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "criterion",
 "ide-core",
@@ -4406,7 +4409,7 @@ dependencies = [

 [[package]]
 name = "ide-host"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "base64 0.22.1",
 "blake3",
@@ -4477,7 +4480,7 @@ dependencies = [

 [[package]]
 name = "ide-http"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-vfs",
@@ -4496,7 +4499,7 @@ dependencies = [

 [[package]]
 name = "ide-index"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "criterion",
@@ -4518,7 +4521,7 @@ dependencies = [

 [[package]]
 name = "ide-jdwp"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-jvm-inspect",
 "proptest",
@@ -4530,7 +4533,7 @@ dependencies = [

 [[package]]
 name = "ide-jsonrpc"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "encoding_rs",
 "futures",
@@ -4547,7 +4550,7 @@ dependencies = [

 [[package]]
 name = "ide-jvm-attach"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "libc",
 "tempfile",
@@ -4556,7 +4559,7 @@ dependencies = [

 [[package]]
 name = "ide-jvm-inspect"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "futures",
 "serde",
@@ -4567,7 +4570,7 @@ dependencies = [

 [[package]]
 name = "ide-language"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "criterion",
@@ -4624,7 +4627,7 @@ dependencies = [

 [[package]]
 name = "ide-lsp"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4652,7 +4655,7 @@ dependencies = [

 [[package]]
 name = "ide-mcp"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "bytes",
 "dunce",
@@ -4671,7 +4674,7 @@ dependencies = [

 [[package]]
 name = "ide-notebook"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "futures",
 "ide-core",
@@ -4694,7 +4697,7 @@ dependencies = [

 [[package]]
 name = "ide-plugin"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "dunce",
@@ -4717,7 +4720,7 @@ dependencies = [

 [[package]]
 name = "ide-profiler"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-jvm-attach",
@@ -4731,7 +4734,7 @@ dependencies = [

 [[package]]
 name = "ide-remote"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dunce",
 "futures",
@@ -4751,7 +4754,7 @@ dependencies = [

 [[package]]
 name = "ide-run"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dunce",
 "encoding_rs",
@@ -4775,7 +4778,7 @@ dependencies = [

 [[package]]
 name = "ide-scaffold"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-tools",
@@ -4791,7 +4794,7 @@ dependencies = [

 [[package]]
 name = "ide-sdk"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dunce",
 "ide-core",
@@ -4812,7 +4815,7 @@ dependencies = [

 [[package]]
 name = "ide-search"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "criterion",
 "encoding_rs",
@@ -4833,7 +4836,7 @@ dependencies = [

 [[package]]
 name = "ide-spell"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "parking_lot",
@@ -4846,7 +4849,7 @@ dependencies = [

 [[package]]
 name = "ide-ssh"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dirs 6.0.0",
 "flate2",
@@ -4871,7 +4874,7 @@ dependencies = [

 [[package]]
 name = "ide-syntax"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "ide-language",
@@ -4886,7 +4889,7 @@ dependencies = [

 [[package]]
 name = "ide-terminal"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "ide-core",
 "libc",
@@ -4899,7 +4902,7 @@ dependencies = [

 [[package]]
 name = "ide-text"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "criterion",
 "ide-core",
@@ -4912,7 +4915,7 @@ dependencies = [

 [[package]]
 name = "ide-tools"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "flate2",
 "hex",
@@ -4933,7 +4936,7 @@ dependencies = [

 [[package]]
 name = "ide-vcs"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "dunce",
@@ -4954,7 +4957,7 @@ dependencies = [

 [[package]]
 name = "ide-vfs"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "chardetng",
 "dunce",
@@ -4978,7 +4981,7 @@ dependencies = [

 [[package]]
 name = "ide-web"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "dirs 6.0.0",
 "ide-core",
@@ -4994,7 +4997,7 @@ dependencies = [

 [[package]]
 name = "ide-workspace"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "blake3",
 "dunce",
@@ -6595,7 +6598,7 @@ dependencies = [

 [[package]]
 name = "openidea"
-version = "0.1.44"
+version = "0.1.45"
 dependencies = [
 "base64 0.22.1",
 "blake3",
@@ -5,7 +5,7 @@ members = ["crates/*", "src-tauri"]
 exclude = ["sdk", "plugins"]

 [workspace.package]
-version = "0.1.44"
+version = "0.1.45"
 edition = "2024"
 rust-version = "1.96"
 license = "Apache-2.0"
@@ -7,6 +7,7 @@ license.workspace = true

 [dependencies]
 encoding_rs.workspace = true
+blake3.workspace = true
 ide-vfs.workspace = true
 ide-core.workspace = true
 ide-mcp.workspace = true
@@ -24,3 +25,6 @@ dunce.workspace = true
 uuid.workspace = true
 tempfile.workspace = true
 which = "8"
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["test-util"] }
@@ -3,6 +3,7 @@
 //! `initialize` alone).

 use super::{Conn, Dialect};
+use crate::catalogs::Discovered;
 use crate::config;
 use crate::model::AgentConfigOption;
 use crate::provider::ProviderSpec;
@@ -15,22 +16,41 @@ use std::time::Duration;
 const DISCOVER_TIMEOUT: Duration = if cfg!(test) { Duration::from_secs(3) } else { Duration::from_secs(120) };

 /// Opens `session/new`, reads `configOptions`, and records per-model `thought_level` choices.
-pub(crate) async fn run(shared: &Arc<Shared>, spec: &ProviderSpec) -> Result<(), String> {
+pub(crate) async fn run(shared: &Arc<Shared>, spec: &ProviderSpec) -> Result<Discovered, String> {
+    let prefer_stored = crate::provider::prefer_stored_copilot_auth();
+    match run_once(shared, spec, prefer_stored).await {
+        Err(err)
+            if !prefer_stored
+                && crate::provider::is_copilot_provider(&spec.id)
+                && crate::provider::has_unconfigured_copilot_ambient_token(&spec.env)
+                && super::auth_required(0, &err) =>
+        {
+            let retry = run_once(shared, spec, true).await;
+            if retry.is_ok() {
+                crate::provider::mark_prefer_stored_copilot_auth();
+            }
+            retry
+        }
+        other => other,
+    }
+}
+
+async fn run_once(shared: &Arc<Shared>, spec: &ProviderSpec, strip_ambient: bool) -> Result<Discovered, String> {
    let root = shared.paths.project_root.clone();
    let launch = spec.clone();
    let launch = tokio::task::spawn_blocking({
        let root = root.clone();
-        move || launch.resolve_for_launch(&root)
+        move || launch.resolve_for_launch_with_copilot_env(&root, strip_ambient)
    })
    .await
    .map_err(|e| e.to_string())?;
    let cwd = dunce::canonicalize(&root).unwrap_or(root);
-    let stderr: Arc<Mutex<Vec<String>>> = Arc::default();
-    let lines = stderr.clone();
-    let on_stderr: Box<dyn Fn(String) + Send + Sync> = Box::new(move |l| lines.lock().push(l));
-    let client = Dialect::wrap(Arc::new(ide_jsonrpc::NoopHandler));
+    let updates = Arc::new(DiscoveryUpdates { provider: spec.id.clone(), commands: Mutex::new(None) });
+    let client = Dialect::wrap(updates.clone());
+    let on_stderr: Box<dyn Fn(String) + Send + Sync> = Box::new(|_| {});
    let peer = (shared.connector)(&launch, &cwd, client.clone(), on_stderr)
        .map_err(|e| format!("Couldn't start {} (`{}`): {e}", launch.name, launch.command))?;
+    let _stop = crate::catalogs::KillPeer(peer.clone());
    let conn = Conn::new(peer.clone(), client);
    let work = async {
        conn.initialize(&client_info()).await.map_err(|e| e.to_string())?;
@@ -51,34 +71,41 @@ pub(crate) async fn run(shared: &Arc<Shared>, spec: &ProviderSpec) -> Result<(),
            (Some(model), Some(effort)) => model.current.clone().map(|m| vec![(m, effort)]).unwrap_or_default(),
            _ => Vec::new(),
        };
-        let option_ids: Vec<_> = options.iter().map(|o| o.id.as_str()).collect();
-        tracing::info!(
-            "agent {}: settings discovery got {} config option(s) {:?}, {} model effort list(s)",
-            launch.id,
-            options.len(),
-            option_ids,
-            levels.len()
-        );
-        shared.remember_discovered(&launch.id, &options, &[], &levels);
-        Ok::<(), String>(())
+        let commands = updates
+            .commands
+            .lock()
+            .clone()
+            .or_else(|| new.get("availableCommands").map(|_| config::commands_of(&new, &launch.id)));
+        Ok::<_, String>(Discovered { config: options, commands, levels: levels.into_iter().collect() })
    };
    let result = tokio::time::timeout(DISCOVER_TIMEOUT, work).await;
    peer.kill();
    match result {
-        Ok(Ok(())) => Ok(()),
-        Ok(Err(e)) => Err(match stderr.lock().last() {
-            Some(line) => format!("{e}: {line}"),
-            None => e,
-        }),
-        Err(_) => {
-            let tail = stderr.lock().join("\n");
-            if tail.is_empty() {
-                Err("the agent did not answer in time".into())
-            } else {
-                Err(format!("the agent did not answer in time:\n{tail}"))
-            }
+        Ok(result) => result,
+        Err(_) => Err("the agent did not answer in time".into()),
+    }
+}
+
+#[derive(Default)]
+struct DiscoveryUpdates {
+    provider: String,
+    commands: Mutex<Option<Vec<crate::AgentCommand>>>,
+}
+
+impl ide_jsonrpc::Handler for DiscoveryUpdates {
+    fn on_notification(&self, method: &str, params: Value) {
+        if method == "session/update"
+            && let Some(update) = params.get("update")
+            && update["sessionUpdate"] == "available_commands_update"
+        {
+            // Commands are protocol data, not stderr (which may contain credentials).
+            *self.commands.lock() = Some(config::commands_of(update, &self.provider));
        }
    }
+
+    fn on_request(&self, method: &str, _: Value) -> Result<Value, (i64, String)> {
+        Err((ide_jsonrpc::codes::METHOD_NOT_FOUND, format!("unsupported discovery request {method}")))
+    }
 }

 fn is_thought_level(o: &AgentConfigOption) -> bool {
@@ -108,6 +108,7 @@ fn manager(dir: &Path, agent: Arc<FakeV2Agent>) -> AgentManager {
            custom_agents_dir: None,
            home_dir: None,
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
        connector,
@@ -155,6 +155,7 @@ async fn discovery_reads_effort_and_fast_from_session_new_then_stops_the_agent()
            custom_agents_dir: None,
            home_dir: None,
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
        connector,
@@ -0,0 +1,427 @@
+//! Model availability for new tasks. Sessions own selections; discovery owns catalogs.
+
+use crate::{
+    AgentCommand, AgentConfigOption, AgentEvent, AgentModelCatalog, Known, Shared, acp, config, native, provider,
+};
+use ide_core::{IdeError, IdeResult};
+use parking_lot::Mutex;
+use serde::{Deserialize, Serialize};
+use std::collections::{BTreeMap, HashMap};
+use std::path::PathBuf;
+use std::sync::{Arc, Weak};
+use std::time::Duration;
+use tokio::sync::watch;
+use tokio::time::Instant;
+
+const FRESH_FOR: Duration = Duration::from_secs(15 * 60);
+const COOLDOWN: Duration = Duration::from_secs(30);
+
+type Store = Arc<Mutex<HashMap<String, Known>>>;
+type Key = (PathBuf, PathBuf, String);
+
+/// Backend-wide single-flight model lookups, scoped to project and effective launch configuration.
+#[derive(Default)]
+pub struct AgentCatalogs {
+    state: Mutex<State>,
+    #[cfg(test)]
+    clock_ms: std::sync::atomic::AtomicU64,
+}
+
+#[derive(Default)]
+struct State {
+    stores: HashMap<PathBuf, Store>,
+    entries: HashMap<Key, Entry>,
+    subscribers: Vec<Weak<Shared>>,
+    generation: u64,
+}
+
+struct Entry {
+    // Launch credentials remain only in memory, never serialized or logged.
+    context: LaunchContext,
+    generation: u64,
+    completed: Option<Instant>,
+    successful: Option<Instant>,
+    retry_at_ms: Option<f64>,
+    error: Option<String>,
+    flight: Option<watch::Receiver<bool>>,
+    abort: Option<tokio::task::AbortHandle>,
+    catalog: Option<CatalogData>,
+}
+
+#[derive(Clone, Default, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct CatalogData {
+    pub config: Vec<AgentConfigOption>,
+    pub thought_levels: BTreeMap<String, Vec<AgentConfigOption>>,
+    pub refreshed_at_ms: Option<f64>,
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub(crate) struct SavedCatalog {
+    /// An opaque cryptographic digest, never raw launch arguments or credentials.
+    fingerprint: String,
+    #[serde(flatten)]
+    catalog: CatalogData,
+}
+
+#[derive(PartialEq)]
+struct LaunchContext {
+    spec: provider::ProviderSpec,
+    executable: PathBuf,
+    modified: Option<std::time::SystemTime>,
+    len: Option<u64>,
+}
+
+impl LaunchContext {
+    fn new(spec: provider::ProviderSpec, root: &std::path::Path) -> Self {
+        let resolved = spec.clone().resolve_for_launch(root);
+        let executable = dunce::canonicalize(&resolved.command).unwrap_or_else(|_| PathBuf::from(&resolved.command));
+        let metadata = std::fs::metadata(&executable).ok();
+        Self {
+            spec,
+            executable,
+            modified: metadata.as_ref().and_then(|m| m.modified().ok()),
+            len: metadata.as_ref().map(std::fs::Metadata::len),
+        }
+    }
+
+    fn fingerprint(&self) -> String {
+        let mut hash = blake3::Hasher::new();
+        fn field(hash: &mut blake3::Hasher, value: &[u8]) {
+            hash.update(&(value.len() as u64).to_le_bytes());
+            hash.update(value);
+        }
+        field(&mut hash, b"openidea-model-catalog-v1");
+        field(
+            &mut hash,
+            match self.spec.driver {
+                provider::Driver::Acp => b"acp",
+                provider::Driver::Codex => b"codex",
+                provider::Driver::Claude => b"claude",
+            },
+        );
+        field(&mut hash, self.spec.command.as_bytes());
+        hash.update(&(self.spec.args.len() as u64).to_le_bytes());
+        for arg in &self.spec.args {
+            field(&mut hash, arg.as_bytes());
+        }
+        hash.update(&(self.spec.env.len() as u64).to_le_bytes());
+        for (name, value) in &self.spec.env {
+            field(&mut hash, name.as_bytes());
+            field(&mut hash, value.as_bytes());
+        }
+        field(&mut hash, self.executable.to_string_lossy().as_bytes());
+        if let Some(modified) = self.modified.and_then(|t| t.duration_since(std::time::UNIX_EPOCH).ok()) {
+            hash.update(&modified.as_nanos().to_le_bytes());
+        }
+        if let Some(len) = self.len {
+            hash.update(&len.to_le_bytes());
+        }
+        hash.finalize().to_hex().to_string()
+    }
+}
+
+pub(crate) struct Discovered {
+    pub config: Vec<AgentConfigOption>,
+    pub commands: Option<Vec<AgentCommand>>,
+    pub levels: BTreeMap<String, Vec<AgentConfigOption>>,
+}
+
+pub(crate) struct KillPeer(pub ide_jsonrpc::Peer);
+
+impl Drop for KillPeer {
+    fn drop(&mut self) {
+        self.0.kill();
+    }
+}
+
+impl AgentCatalogs {
+    fn now(&self) -> Instant {
+        let now = Instant::now();
+        #[cfg(test)]
+        let now = now + Duration::from_millis(self.clock_ms.load(std::sync::atomic::Ordering::Relaxed));
+        now
+    }
+
+    fn epoch_ms(&self) -> f64 {
+        let now = crate::now_ms();
+        #[cfg(test)]
+        let now = now + self.clock_ms.load(std::sync::atomic::Ordering::Relaxed) as f64;
+        now
+    }
+
+    pub(crate) fn store(&self, path: &std::path::Path) -> Store {
+        self.state
+            .lock()
+            .stores
+            .entry(path.to_path_buf())
+            .or_insert_with(|| {
+                Arc::new(Mutex::new(
+                    std::fs::read(path).ok().and_then(|b| serde_json::from_slice(&b).ok()).unwrap_or_default(),
+                ))
+            })
+            .clone()
+    }
+
+    pub(crate) fn subscribe(&self, shared: &Arc<Shared>) {
+        let mut state = self.state.lock();
+        state.subscribers.retain(|s| s.strong_count() > 0);
+        state.subscribers.push(Arc::downgrade(shared));
+    }
+
+    fn key(shared: &Shared, provider: &str) -> Key {
+        (shared.paths.models_file.clone(), shared.paths.project_root.clone(), provider.to_owned())
+    }
+
+    fn fallback(shared: &Shared, provider: &str) -> CatalogData {
+        let cache = shared.known.lock();
+        let Some(known) = cache.get(provider) else { return CatalogData::default() };
+        known.catalogs.get(&shared.root_key()).map(|saved| saved.catalog.clone()).unwrap_or_else(|| CatalogData {
+            config: known.config.clone(),
+            thought_levels: known.thought_levels.clone(),
+            refreshed_at_ms: None,
+        })
+    }
+
+    pub(crate) fn cached(&self, shared: &Shared, provider: &str) -> CatalogData {
+        self.state
+            .lock()
+            .entries
+            .get(&Self::key(shared, provider))
+            .and_then(|e| e.catalog.clone())
+            .unwrap_or_else(|| Self::fallback(shared, provider))
+    }
+
+    fn snapshot(&self, shared: &Shared, provider: &str, entry: &Entry) -> AgentModelCatalog {
+        let catalog = entry.catalog.clone().unwrap_or_else(|| Self::fallback(shared, provider));
+        AgentModelCatalog {
+            provider: provider.to_owned(),
+            config: shared.config_for_new_task(catalog.config, provider),
+            thought_levels: catalog.thought_levels,
+            refreshing: entry.flight.is_some(),
+            refreshed_at_ms: catalog.refreshed_at_ms,
+            retry_at_ms: entry
+                .retry_at_ms
+                .filter(|_| entry.completed.is_some_and(|at| self.now().duration_since(at) < COOLDOWN)),
+            error: entry.error.clone(),
+        }
+    }
+
+    /// Start or join a lookup. No queued refresh can outlive the request that asked for it.
+    pub(crate) fn request(
+        self: &Arc<Self>,
+        shared: &Arc<Shared>,
+        spec: provider::ProviderSpec,
+        force: bool,
+    ) -> (AgentModelCatalog, Option<watch::Receiver<bool>>) {
+        let key = Self::key(shared, &spec.id);
+        let context = LaunchContext::new(spec.clone(), &shared.paths.project_root);
+        let now = self.now();
+        let mut state = self.state.lock();
+        let changed = state.entries.get(&key).is_none_or(|e| e.context != context);
+        if changed {
+            if let Some(abort) = state.entries.get_mut(&key).and_then(|entry| entry.abort.take()) {
+                abort.abort();
+            }
+            state.generation += 1;
+            let generation = state.generation;
+            let saved =
+                shared.known.lock().get(&spec.id).and_then(|known| known.catalogs.get(&shared.root_key())).cloned();
+            let matching = saved.as_ref().is_some_and(|saved| saved.fingerprint == context.fingerprint());
+            let age = saved
+                .as_ref()
+                .filter(|_| matching)
+                .and_then(|saved| saved.catalog.refreshed_at_ms)
+                .map(|at| self.epoch_ms() - at)
+                .filter(|age| *age >= 0.0 && *age < FRESH_FOR.as_millis() as f64)
+                .map(|age| Duration::from_secs_f64(age / 1000.0));
+            let successful = age.and_then(|age| now.checked_sub(age));
+            let completed = age.filter(|age| *age < COOLDOWN).and_then(|age| now.checked_sub(age));
+            let retry_at_ms = completed
+                .and_then(|_| saved.as_ref().and_then(|s| s.catalog.refreshed_at_ms))
+                .map(|at| at + COOLDOWN.as_millis() as f64);
+            let catalog = saved.map(|saved| {
+                let mut catalog = saved.catalog;
+                if !matching {
+                    catalog.refreshed_at_ms = None;
+                }
+                catalog
+            });
+            state.entries.insert(
+                key.clone(),
+                Entry {
+                    context,
+                    generation,
+                    completed,
+                    successful,
+                    retry_at_ms,
+                    catalog,
+                    error: None,
+                    flight: None,
+                    abort: None,
+                },
+            );
+        }
+        let entry = state.entries.get_mut(&key).expect("catalog entry");
+        let cooling = entry.completed.is_some_and(|at| now.duration_since(at) < COOLDOWN);
+        let fresh = entry.successful.is_some_and(|at| now.duration_since(at) < FRESH_FOR);
+        let mut start = None;
+        if entry.flight.is_none() && !cooling && (force || !fresh) {
+            let (done, ready) = watch::channel(false);
+            entry.flight = Some(ready);
+            entry.error = None;
+            entry.retry_at_ms = None;
+            start = Some((entry.generation, done));
+        }
+        let snapshot = self.snapshot(shared, &spec.id, entry);
+        let flight = entry.flight.clone();
+        drop(state);
+        if let Some((generation, done)) = start {
+            self.broadcast(shared, &snapshot);
+            let coordinator = self.clone();
+            let shared = shared.clone();
+            let flight_key = key.clone();
+            let task = shared.runtime.clone().spawn(async move {
+                let result = discover(&shared, spec).await;
+                coordinator.complete(&shared, flight_key, generation, result);
+                let _ = done.send(true);
+            });
+            // A subscriber can re-enter and change configuration during the start event.
+            let mut state = self.state.lock();
+            if let Some(entry) = state.entries.get_mut(&key).filter(|entry| entry.generation == generation) {
+                if entry.flight.is_some() {
+                    entry.abort = Some(task.abort_handle());
+                }
+            } else {
+                task.abort();
+            }
+        }
+        (snapshot, flight)
+    }
+
+    fn complete(&self, shared: &Shared, key: Key, generation: u64, result: Result<Discovered, String>) {
+        let current = provider::load(shared.paths.custom_agents_dir.as_deref(), shared.env_secrets())
+            .into_iter()
+            .find(|spec| spec.id == key.2)
+            .map(|spec| LaunchContext::new(spec, &shared.paths.project_root));
+        let mut state = self.state.lock();
+        let Some(entry) = state.entries.get_mut(&key).filter(|e| e.generation == generation) else { return };
+        // Configuration may have changed without another refresh request arriving.
+        if current.as_ref() != Some(&entry.context) {
+            entry.flight = None;
+            entry.abort = None;
+            entry.completed = None;
+            entry.retry_at_ms = None;
+            entry.error = None;
+            let snapshot = self.snapshot(shared, &key.2, entry);
+            state.entries.remove(&key);
+            drop(state);
+            self.broadcast(shared, &snapshot);
+            return;
+        }
+        let now = self.now();
+        entry.completed = Some(now);
+        entry.retry_at_ms = Some(self.epoch_ms() + COOLDOWN.as_millis() as f64);
+        entry.flight = None;
+        entry.abort = None;
+        let success = match result {
+            Ok(found) => {
+                let mut cache = shared.known.lock();
+                let known = cache.entry(key.2.clone()).or_default();
+                let catalog = CatalogData {
+                    config: found.config,
+                    thought_levels: found.levels,
+                    refreshed_at_ms: Some(self.epoch_ms()),
+                };
+                known.config = catalog.config.clone();
+                known.thought_levels = catalog.thought_levels.clone();
+                if let Some(commands) = found.commands {
+                    known.commands.insert(shared.root_key(), commands);
+                }
+                known.authoritative = true;
+                known.refreshed_at_ms = catalog.refreshed_at_ms;
+                known.catalogs.insert(
+                    shared.root_key(),
+                    SavedCatalog { fingerprint: entry.context.fingerprint(), catalog: catalog.clone() },
+                );
+                entry.catalog = Some(catalog);
+                shared.persist_known(&cache);
+                entry.successful = Some(now);
+                entry.error = None;
+                true
+            }
+            Err(error) => {
+                entry.error = Some(error);
+                false
+            }
+        };
+        let snapshot = self.snapshot(shared, &key.2, entry);
+        drop(state);
+        self.broadcast(shared, &snapshot);
+        if success {
+            for subscriber in self.subscribers(shared) {
+                subscriber.emit(AgentEvent::Providers);
+            }
+        }
+    }
+
+    fn subscribers(&self, shared: &Shared) -> Vec<Arc<Shared>> {
+        self.state
+            .lock()
+            .subscribers
+            .iter()
+            .filter_map(Weak::upgrade)
+            .filter(|s| {
+                s.paths.models_file == shared.paths.models_file && s.paths.project_root == shared.paths.project_root
+            })
+            .collect()
+    }
+
+    fn broadcast(&self, shared: &Shared, catalog: &AgentModelCatalog) {
+        for subscriber in self.subscribers(shared) {
+            subscriber.emit(AgentEvent::ModelCatalog { catalog: catalog.clone() });
+        }
+    }
+}
+
+impl crate::AgentManager {
+    /// Return cached choices immediately and schedule discovery when eligible.
+    pub fn refresh_models(&self, provider: &str, force: bool) -> IdeResult<AgentModelCatalog> {
+        // Settings and environment secrets can change while this window is open.
+        *self.shared.providers.write() =
+            provider::load(self.shared.paths.custom_agents_dir.as_deref(), self.shared.env_secrets());
+        let spec = self.shared.spec(provider).ok_or_else(|| IdeError::invalid(format!("unknown agent {provider}")))?;
+        Ok(self.shared.paths.catalogs.request(&self.shared, spec, force).0)
+    }
+}
+
+async fn discover(shared: &Arc<Shared>, spec: provider::ProviderSpec) -> Result<Discovered, String> {
+    match spec.driver {
+        provider::Driver::Acp => acp::discover::run(shared, &spec).await,
+        provider::Driver::Codex => native::codex::discover(spec, shared.paths.project_root.clone()).await,
+        provider::Driver::Claude => {
+            let found = native::claude::discover(spec.clone(), shared.paths.project_root.clone()).await?;
+            Ok(Discovered {
+                commands: Some(config::commands_of(
+                    &serde_json::json!({ "availableCommands": found.commands }),
+                    &spec.id,
+                )),
+                config: config::options_of(&serde_json::json!({ "configOptions": found.options })),
+                levels: found
+                    .efforts
+                    .into_iter()
+                    .map(|(model, option)| {
+                        let levels = option
+                            .map(|o| config::options_of(&serde_json::json!({ "configOptions": [o] })))
+                            .unwrap_or_default();
+                        (model, levels)
+                    })
+                    .collect(),
+            })
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests;
@@ -0,0 +1,501 @@
+use super::*;
+use crate::{AgentManager, AgentPaths, Connector};
+use ide_jsonrpc::{Framing, Peer};
+use serde_json::{Value, json};
+use std::path::Path;
+use std::sync::atomic::{AtomicUsize, Ordering};
+use tokio::io::{AsyncBufReadExt, AsyncWriteExt, BufReader};
+use tokio::sync::{mpsc, oneshot};
+
+const PROVIDER: &str = "catalog-test";
+
+#[derive(Debug)]
+struct Pending {
+    params: Value,
+    reply: oneshot::Sender<Result<Value, String>>,
+}
+
+struct Harness {
+    connector: Connector,
+    pending: mpsc::UnboundedReceiver<Pending>,
+    launches: Arc<AtomicUsize>,
+    live: Arc<AtomicUsize>,
+}
+
+struct Live(Arc<AtomicUsize>);
+impl Drop for Live {
+    fn drop(&mut self) {
+        self.0.fetch_sub(1, Ordering::SeqCst);
+    }
+}
+
+impl Harness {
+    fn new() -> Self {
+        let (pending_tx, pending) = mpsc::unbounded_channel();
+        let launches = Arc::new(AtomicUsize::new(0));
+        let live = Arc::new(AtomicUsize::new(0));
+        let connector: Connector = Arc::new({
+            let launches = launches.clone();
+            let live = live.clone();
+            move |_, _, client, _| {
+                launches.fetch_add(1, Ordering::SeqCst);
+                live.fetch_add(1, Ordering::SeqCst);
+                let guard = Live(live.clone());
+                let pending = pending_tx.clone();
+                let (client_io, server_io) = tokio::io::duplex(1 << 16);
+                let (read, mut write) = tokio::io::split(server_io);
+                tokio::spawn(async move {
+                    let _guard = guard;
+                    let mut lines = BufReader::new(read).lines();
+                    while let Some(line) = lines.next_line().await.unwrap() {
+                        let request: Value = serde_json::from_str(&line).unwrap();
+                        let id = &request["id"];
+                        if id.is_null() {
+                            continue;
+                        }
+                        let response = match request["method"].as_str().unwrap() {
+                            "initialize" => json!({ "id": id, "jsonrpc": "2.0", "result": {
+                                "protocolVersion": 1, "agentCapabilities": {}, "authMethods": [] } }),
+                            "session/new" => {
+                                let (reply, result) = oneshot::channel();
+                                pending.send(Pending { params: request["params"].clone(), reply }).unwrap();
+                                let result = tokio::select! {
+                                    result = result => result.unwrap(),
+                                    _ = lines.next_line() => break,
+                                };
+                                match result {
+                                    Ok(result) => json!({ "id": id, "jsonrpc": "2.0", "result": result }),
+                                    Err(error) => {
+                                        json!({ "id": id, "jsonrpc": "2.0", "error": { "code": -32000, "message": error } })
+                                    }
+                                }
+                            }
+                            method => panic!("discovery must not call {method}"),
+                        };
+                        if write.write_all(format!("{response}\n").as_bytes()).await.is_err() {
+                            break;
+                        }
+                    }
+                });
+                let (read, write) = tokio::io::split(client_io);
+                Ok(Peer::connect_framed(read, write, client, Framing::Lines))
+            }
+        });
+        Self { connector, pending, launches, live }
+    }
+
+    async fn next(&mut self) -> Pending {
+        tokio::time::timeout(Duration::from_secs(5), self.pending.recv()).await.unwrap().unwrap()
+    }
+}
+
+fn configure(root: &Path, version: &str) {
+    std::fs::create_dir_all(root.join("agents")).unwrap();
+    let executable = root.join("catalog-test-bin");
+    if !executable.exists() {
+        std::fs::write(&executable, "first executable").unwrap();
+    }
+    std::fs::write(
+        root.join("agents/catalog-test.toml"),
+        format!(
+            "name = \"Catalog Test\"\ncommand = {}\n[env]\nTOKEN = \"secret-{version}\"\n",
+            serde_json::to_string(&executable.to_string_lossy()).unwrap()
+        ),
+    )
+    .unwrap();
+}
+
+fn make_manager(root: &Path, catalogs: Arc<AgentCatalogs>, harness: &Harness) -> AgentManager {
+    make_manager_at(root, &root.join("models.json"), catalogs, harness)
+}
+
+fn make_manager_at(root: &Path, models_file: &Path, catalogs: Arc<AgentCatalogs>, harness: &Harness) -> AgentManager {
+    AgentManager::with_connector(
+        AgentPaths {
+            project_root: root.to_path_buf(),
+            store_dir: root.join("store"),
+            worktrees_dir: root.join("worktrees"),
+            models_file: models_file.to_path_buf(),
+            catalogs,
+            custom_agents_dir: Some(root.join("agents")),
+            home_dir: Some(root.to_path_buf()),
+            env_secrets: None,
+        },
+        tokio::runtime::Handle::current(),
+        harness.connector.clone(),
+    )
+}
+
+fn events(manager: &AgentManager) -> mpsc::UnboundedReceiver<AgentEvent> {
+    let (tx, rx) = mpsc::unbounded_channel();
+    manager.subscribe(Arc::new(move |event| {
+        let _ = tx.send(event);
+    }));
+    rx
+}
+
+async fn completed(events: &mut mpsc::UnboundedReceiver<AgentEvent>) -> AgentModelCatalog {
+    tokio::time::timeout(Duration::from_secs(5), async {
+        loop {
+            if let AgentEvent::ModelCatalog { catalog } = events.recv().await.unwrap()
+                && !catalog.refreshing
+            {
+                return catalog;
+            }
+        }
+    })
+    .await
+    .unwrap()
+}
+
+fn response(models: &[&str], effort: &[&str]) -> Value {
+    json!({ "sessionId": "discovery-only", "configOptions": [
+        { "id": "model", "type": "select", "category": "model", "currentValue": models.first(),
+          "options": models.iter().map(|m| json!({ "value": m, "name": m })).collect::<Vec<_>>() },
+        { "id": "effort", "type": "select", "category": "thought_level", "currentValue": effort.first(),
+          "options": effort.iter().map(|e| json!({ "value": e })).collect::<Vec<_>>() }
+    ] })
+}
+
+fn model_values(catalog: &AgentModelCatalog) -> Vec<&str> {
+    catalog
+        .config
+        .iter()
+        .filter(|o| o.category.as_deref() == Some("model"))
+        .flat_map(|o| o.values.iter().map(|v| v.value.as_str()))
+        .collect()
+}
+
+async fn stopped(harness: &Harness) {
+    tokio::time::timeout(Duration::from_secs(5), async {
+        while harness.live.load(Ordering::SeqCst) != 0 {
+            tokio::task::yield_now().await;
+        }
+    })
+    .await
+    .unwrap();
+}
+
+fn advance(catalogs: &AgentCatalogs, seconds: u64) {
+    catalogs.clock_ms.fetch_add(seconds * 1000, Ordering::Relaxed);
+}
+
+#[tokio::test]
+async fn successful_refresh_replaces_models_and_efforts_and_old_sessions_cannot_revert_it() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut events = events(&manager);
+    let old = config::options_of(&response(&["old", "retained"], &["low", "high"]));
+    manager.shared.remember(PROVIDER, Some(&old), None, Some("old"));
+    let cached = manager.refresh_models(PROVIDER, false).unwrap();
+    assert!(cached.refreshing);
+    assert_eq!(model_values(&cached), ["old", "retained"]);
+    assert!(cached.refreshed_at_ms.is_none(), "session reports are not fresh discovery");
+    let pending = harness.next().await;
+    assert_eq!(pending.params["mcpServers"], json!([]));
+    pending.reply.send(Ok(response(&["retained", "new"], &["medium"]))).unwrap();
+    let fresh = completed(&mut events).await;
+    assert_eq!(model_values(&fresh), ["retained", "new"]);
+    assert_eq!(fresh.thought_levels.keys().map(String::as_str).collect::<Vec<_>>(), ["new", "retained"]);
+    assert_eq!(fresh.thought_levels["retained"][0].values[0].value, "medium");
+    assert!(fresh.refreshed_at_ms.is_some() && fresh.retry_at_ms.is_some());
+    manager.shared.remember(PROVIDER, Some(&old), None, Some("old"));
+    assert_eq!(manager.refresh_models(PROVIDER, false).unwrap().config, fresh.config);
+    let provider = manager.providers().into_iter().find(|p| p.id == PROVIDER).unwrap();
+    assert_eq!(provider.config, fresh.config);
+    let persisted = std::fs::read_to_string(tmp.path().join("models.json")).unwrap();
+    assert!(!persisted.contains("secret-one") && !persisted.contains("TOKEN"));
+    let restored = make_manager(tmp.path(), Arc::default(), &harness);
+    let restored_snapshot = restored.refresh_models(PROVIDER, false).unwrap();
+    assert!(!restored_snapshot.refreshing, "matching persisted launch context remains fresh");
+    assert_eq!(restored_snapshot.refreshed_at_ms, fresh.refreshed_at_ms);
+    let provider = restored.providers().into_iter().find(|p| p.id == PROVIDER).unwrap();
+    assert_eq!(provider.config, fresh.config);
+    restored.shared.remember(PROVIDER, Some(&old), None, Some("old"));
+    assert_eq!(restored.shared.known_config(PROVIDER), fresh.config);
+    assert_eq!(restored.shared.known.lock()[PROVIDER].refreshed_at_ms, fresh.refreshed_at_ms);
+    assert!(!tmp.path().join("store").exists(), "refresh never creates tasks");
+}
+
+#[tokio::test]
+async fn legacy_cache_loads_without_claiming_authoritative_freshness() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let options = config::options_of(&response(&["legacy"], &["low"]));
+    std::fs::write(
+        tmp.path().join("models.json"),
+        serde_json::to_vec(&json!({
+            (PROVIDER): { "config": options, "thoughtLevels": {}, "projectCommands": {} }
+        }))
+        .unwrap(),
+    )
+    .unwrap();
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), Arc::default(), &harness);
+    let mut events = events(&manager);
+    let cached = manager.refresh_models(PROVIDER, false).unwrap();
+    assert_eq!(model_values(&cached), ["legacy"]);
+    assert!(cached.refreshing && cached.refreshed_at_ms.is_none());
+    harness.next().await.reply.send(Err("Sign in required".into())).unwrap();
+    let failed = completed(&mut events).await;
+    assert_eq!(failed.config, cached.config);
+    assert!(failed.error.as_deref().unwrap().contains("Sign in required"));
+}
+
+#[tokio::test]
+async fn concurrent_windows_commands_and_manual_requests_share_one_flight_and_cooldown() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let first = Arc::new(make_manager(tmp.path(), catalogs.clone(), &harness));
+    let second = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut first_events = events(&first);
+    let mut second_events = events(&second);
+    assert!(first.refresh_models(PROVIDER, false).unwrap().refreshing);
+    let pending = harness.next().await;
+    for _ in 0..10 {
+        assert!(second.refresh_models(PROVIDER, true).unwrap().refreshing);
+        assert!(first.refresh_models(PROVIDER, true).unwrap().refreshing);
+    }
+    let commands = tokio::spawn({
+        let first = first.clone();
+        async move { first.commands(PROVIDER, None).await }
+    });
+    tokio::task::yield_now().await;
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 1);
+    pending.reply.send(Ok(response(&["one"], &["low"]))).unwrap();
+    let done = completed(&mut first_events).await;
+    assert_eq!(completed(&mut second_events).await, done);
+    commands.await.unwrap().unwrap();
+    for force in [false, true, false, true] {
+        assert!(!second.refresh_models(PROVIDER, force).unwrap().refreshing);
+    }
+    advance(&catalogs, 29);
+    assert!(!first.refresh_models(PROVIDER, true).unwrap().refreshing);
+    advance(&catalogs, 1);
+    assert!(!first.refresh_models(PROVIDER, false).unwrap().refreshing, "automatic refresh remains fresh");
+    assert!(first.refresh_models(PROVIDER, true).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["two"], &["high"]))).unwrap();
+    let newer = completed(&mut first_events).await;
+    assert_eq!(model_values(&newer), ["two"]);
+    assert_eq!(completed(&mut second_events).await, newer);
+    advance(&catalogs, 15 * 60 - 1);
+    assert!(!second.refresh_models(PROVIDER, false).unwrap().refreshing);
+    advance(&catalogs, 1);
+    assert!(second.refresh_models(PROVIDER, false).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["three"], &["low"]))).unwrap();
+    completed(&mut first_events).await;
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 3);
+}
+
+#[tokio::test]
+async fn failure_keeps_successful_choices_and_throttles_manual_and_auto_retries() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut events = events(&manager);
+    manager.refresh_models(PROVIDER, true).unwrap();
+    harness.next().await.reply.send(Ok(response(&["cached"], &["low"]))).unwrap();
+    let success = completed(&mut events).await;
+    let disk = std::fs::read(tmp.path().join("models.json")).unwrap();
+    advance(&catalogs, 15 * 60);
+    manager.refresh_models(PROVIDER, false).unwrap();
+    harness.next().await.reply.send(Err("Authentication expired".into())).unwrap();
+    let failed = completed(&mut events).await;
+    assert_eq!(failed.config, success.config);
+    assert_eq!(failed.thought_levels, success.thought_levels);
+    assert_eq!(failed.refreshed_at_ms, success.refreshed_at_ms);
+    assert!(failed.error.as_deref().unwrap().contains("Authentication expired"));
+    assert_eq!(std::fs::read(tmp.path().join("models.json")).unwrap(), disk);
+    assert!(!manager.refresh_models(PROVIDER, false).unwrap().refreshing);
+    assert!(!manager.refresh_models(PROVIDER, true).unwrap().refreshing);
+    advance(&catalogs, 29);
+    assert!(!manager.refresh_models(PROVIDER, true).unwrap().refreshing);
+    advance(&catalogs, 1);
+    assert!(manager.refresh_models(PROVIDER, false).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["recovered"], &["high"]))).unwrap();
+    let recovered = completed(&mut events).await;
+    assert_eq!(model_values(&recovered), ["recovered"]);
+    assert!(recovered.error.is_none());
+}
+
+#[tokio::test]
+async fn timeout_cleans_up_and_enters_the_same_failure_cooldown() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut events = events(&manager);
+    manager.refresh_models(PROVIDER, false).unwrap();
+    let pending = harness.next().await;
+    tokio::time::pause();
+    tokio::time::advance(Duration::from_secs(4)).await;
+    let failed = completed(&mut events).await;
+    assert!(failed.error.as_deref().unwrap().contains("time"));
+    assert!(failed.retry_at_ms.is_some());
+    assert!(!manager.refresh_models(PROVIDER, true).unwrap().refreshing);
+    assert!(!manager.refresh_models(PROVIDER, false).unwrap().refreshing);
+    tokio::time::resume();
+    stopped(&harness).await;
+    assert_eq!(harness.live.load(Ordering::SeqCst), 0, "timed-out connection must close");
+    assert!(pending.reply.is_closed());
+    advance(&catalogs, 30);
+    assert!(manager.refresh_models(PROVIDER, false).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["retry"], &["low"]))).unwrap();
+    completed(&mut events).await;
+}
+
+#[tokio::test]
+async fn changed_effective_config_supersedes_old_completion_without_queueing() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let first = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let second = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut events = events(&second);
+    first.refresh_models(PROVIDER, false).unwrap();
+    let obsolete = harness.next().await;
+    configure(tmp.path(), "two");
+    assert!(second.refresh_models(PROVIDER, false).unwrap().refreshing);
+    let latest = harness.next().await;
+    latest.reply.send(Ok(response(&["latest"], &["high"]))).unwrap();
+    let fresh = completed(&mut events).await;
+    let _ = obsolete.reply.send(Ok(response(&["obsolete"], &["low"])));
+    stopped(&harness).await;
+    let shown = first.refresh_models(PROVIDER, false).unwrap();
+    assert_eq!(shown.config, fresh.config);
+    assert_eq!(shown.refreshed_at_ms, fresh.refreshed_at_ms);
+    assert!(!shown.refreshing);
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 2);
+    assert!(!std::fs::read_to_string(tmp.path().join("models.json")).unwrap().contains("obsolete"));
+    // A changed configuration also invalidates successful freshness/cooldown.
+    configure(tmp.path(), "three");
+    assert!(first.refresh_models(PROVIDER, false).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["new-config"], &["medium"]))).unwrap();
+    completed(&mut events).await;
+}
+
+#[tokio::test]
+async fn invalid_provider_is_a_request_error_and_does_not_launch() {
+    let tmp = tempfile::tempdir().unwrap();
+    let harness = Harness::new();
+    let manager = make_manager(tmp.path(), Arc::default(), &harness);
+    assert!(manager.refresh_models("missing-provider", true).is_err());
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 0);
+}
+
+#[tokio::test]
+async fn replacing_the_executable_at_the_same_path_invalidates_freshness_and_obsolete_responses() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "unchanged-environment");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), catalogs, &harness);
+    let mut events = events(&manager);
+    manager.refresh_models(PROVIDER, false).unwrap();
+    let obsolete = harness.next().await;
+    std::fs::write(tmp.path().join("catalog-test-bin"), "replacement executable with different size").unwrap();
+    manager.refresh_models(PROVIDER, false).unwrap();
+    let latest = harness.next().await;
+    latest.reply.send(Ok(response(&["updated"], &["high"]))).unwrap();
+    let fresh = completed(&mut events).await;
+    let _ = obsolete.reply.send(Ok(response(&["obsolete"], &["low"])));
+    stopped(&harness).await;
+    assert_eq!(manager.refresh_models(PROVIDER, false).unwrap().config, fresh.config);
+    std::fs::write(tmp.path().join("catalog-test-bin"), "another executable").unwrap();
+    assert!(manager.refresh_models(PROVIDER, false).unwrap().refreshing);
+    harness.next().await.reply.send(Ok(response(&["new-install"], &["medium"]))).unwrap();
+    assert_eq!(model_values(&completed(&mut events).await), ["new-install"]);
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 3);
+}
+
+#[tokio::test]
+async fn project_catalogs_and_persisted_freshness_do_not_leak_between_contexts() {
+    let tmp = tempfile::tempdir().unwrap();
+    let a = tmp.path().join("project-a");
+    let b = tmp.path().join("project-b");
+    configure(&a, "account-a");
+    configure(&b, "account-b");
+    let models_file = tmp.path().join("shared-models.json");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let first = make_manager_at(&a, &models_file, catalogs.clone(), &harness);
+    let second = make_manager_at(&b, &models_file, catalogs, &harness);
+    let mut first_events = events(&first);
+    let mut second_events = events(&second);
+    first.refresh_models(PROVIDER, false).unwrap();
+    harness.next().await.reply.send(Ok(response(&["account-a-model"], &["low"]))).unwrap();
+    let a_catalog = completed(&mut first_events).await;
+    second.refresh_models(PROVIDER, false).unwrap();
+    harness.next().await.reply.send(Ok(response(&["account-b-model"], &["high"]))).unwrap();
+    let b_catalog = completed(&mut second_events).await;
+    assert_eq!(first.refresh_models(PROVIDER, false).unwrap().config, a_catalog.config);
+    assert_eq!(second.refresh_models(PROVIDER, false).unwrap().config, b_catalog.config);
+    assert_eq!(first.providers().into_iter().find(|p| p.id == PROVIDER).unwrap().config, a_catalog.config);
+    for (root, expected) in [(&a, &a_catalog), (&b, &b_catalog)] {
+        let restored = make_manager_at(root, &models_file, Arc::default(), &harness);
+        let cached = restored.refresh_models(PROVIDER, false).unwrap();
+        assert!(!cached.refreshing, "matching persisted context should retain freshness");
+        assert_eq!(cached.config, expected.config);
+        assert_eq!(cached.refreshed_at_ms, expected.refreshed_at_ms);
+    }
+    assert_eq!(harness.launches.load(Ordering::SeqCst), 2);
+    configure(&a, "new-account");
+    let changed = make_manager_at(&a, &models_file, Arc::default(), &harness);
+    let mut events = events(&changed);
+    let stale = changed.refresh_models(PROVIDER, false).unwrap();
+    assert!(stale.refreshing, "a different launch environment cannot reuse persisted freshness");
+    assert!(stale.refreshed_at_ms.is_none());
+    assert_eq!(stale.config, a_catalog.config, "stale cached choices remain selectable");
+    harness.next().await.reply.send(Ok(response(&["new-account-model"], &["medium"]))).unwrap();
+    completed(&mut events).await;
+    let persisted = std::fs::read_to_string(models_file).unwrap();
+    assert!(!persisted.contains("secret-") && !persisted.contains("TOKEN"));
+}
+
+#[tokio::test]
+async fn configuration_changed_without_another_request_also_discards_old_discovery() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "before");
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), Arc::default(), &harness);
+    let mut events = events(&manager);
+    manager.refresh_models(PROVIDER, false).unwrap();
+    let obsolete = harness.next().await;
+    configure(tmp.path(), "after");
+    obsolete.reply.send(Ok(response(&["obsolete"], &["low"]))).unwrap();
+    let discarded = completed(&mut events).await;
+    assert!(model_values(&discarded).is_empty());
+    assert!(discarded.refreshed_at_ms.is_none());
+    assert!(!tmp.path().join("models.json").exists());
+    manager.refresh_models(PROVIDER, false).unwrap();
+    harness.next().await.reply.send(Ok(response(&["current"], &["high"]))).unwrap();
+    assert_eq!(model_values(&completed(&mut events).await), ["current"]);
+}
+
+#[tokio::test]
+async fn successful_empty_catalog_removes_all_previous_models_and_efforts() {
+    let tmp = tempfile::tempdir().unwrap();
+    configure(tmp.path(), "one");
+    let catalogs = Arc::new(AgentCatalogs::default());
+    let mut harness = Harness::new();
+    let manager = make_manager(tmp.path(), catalogs.clone(), &harness);
+    let mut events = events(&manager);
+    manager.refresh_models(PROVIDER, true).unwrap();
+    harness.next().await.reply.send(Ok(response(&["removed"], &["low"]))).unwrap();
+    completed(&mut events).await;
+    advance(&catalogs, 30);
+    manager.refresh_models(PROVIDER, true).unwrap();
+    harness.next().await.reply.send(Ok(response(&[], &[]))).unwrap();
+    let empty = completed(&mut events).await;
+    assert!(model_values(&empty).is_empty() && empty.thought_levels.is_empty());
+    assert!(empty.refreshed_at_ms.is_some() && empty.error.is_none());
+}
@@ -8,6 +8,7 @@
 //! next prompt when the agent supports `session/load`.

 mod acp;
+mod catalogs;
 mod config;
 mod conversation;
 mod external;
@@ -21,6 +22,7 @@ mod skills;
 mod timeline;
 mod worktree;

+pub use catalogs::AgentCatalogs;
 pub use external::ExternalSession;
 pub use model::*;

@@ -88,6 +90,8 @@ pub struct AgentPaths {
    pub worktrees_dir: PathBuf,
    /// Settings each agent offered last time (shared by all projects), and its commands per project.
    pub models_file: PathBuf,
+    /// Shared by every project/window on this backend.
+    pub catalogs: Arc<AgentCatalogs>,
    /// User-defined agents, one `<id>.toml` each (`name`, `command`, `args`, `env`).
    pub custom_agents_dir: Option<PathBuf>,
    /// The user's home: its `.claude` holds their own skills and commands.
@@ -123,12 +127,10 @@ struct Shared {
    sink: RwLock<Option<AgentSink>>,
    security: RwLock<Option<SecurityHook>>,
    new_task_approvals: RwLock<Option<NewTaskApprovalsHook>>,
-    known: Mutex<HashMap<String, Known>>,
+    known: Arc<Mutex<HashMap<String, Known>>>,
    providers: RwLock<Vec<provider::ProviderSpec>>,
    /// Last probe of each provider.
    probes: Mutex<HashMap<String, AgentProbe>>,
-    /// One pre-session lookup of commands and settings per provider, including failed attempts.
-    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>>>,
@@ -145,6 +147,14 @@ struct Known {
    /// By project root: skills and custom commands differ per project.
    #[serde(default, rename = "projectCommands")]
    commands: HashMap<String, Vec<AgentCommand>>,
+    /// Successful discovery, unlike a session report, owns availability.
+    #[serde(default)]
+    authoritative: bool,
+    #[serde(default, rename = "refreshedAtMs")]
+    refreshed_at_ms: Option<f64>,
+    /// Authoritative availability and freshness are scoped to project and launch context.
+    #[serde(default, rename = "projectCatalogs")]
+    catalogs: HashMap<String, catalogs::SavedCatalog>,
 }

 impl Shared {
@@ -171,7 +181,11 @@ impl Shared {
    }

    fn known_config(&self, provider: &str) -> Vec<AgentConfigOption> {
-        let mut config = self.known.lock().get(provider).map(|k| k.config.clone()).unwrap_or_default();
+        let config = self.paths.catalogs.cached(self, provider).config;
+        self.config_for_new_task(config, provider)
+    }
+
+    fn config_for_new_task(&self, mut config: Vec<AgentConfigOption>, provider: &str) -> Vec<AgentConfigOption> {
        // Model-specific options are offered separately, never as provider-wide defaults.
        config.retain(|o| o.category.as_deref() != Some("thought_level"));
        config::add_client_options(provider, &mut config);
@@ -197,80 +211,6 @@ impl Shared {
        cache.get(provider).and_then(|k| k.commands.get(&self.root_key())).cloned().unwrap_or_default()
    }

-    async fn fetch_settings(self: &Arc<Self>, spec: provider::ProviderSpec) {
-        let mut ready = {
-            let mut fetches = self.command_fetches.lock();
-            fetches
-                .entry(spec.id.clone())
-                .or_insert_with(|| {
-                    let (done, ready) = tokio::sync::watch::channel(false);
-                    let shared = self.clone();
-                    // Keep the lookup alive if a composer unmounts while it is waiting.
-                    self.runtime.spawn(async move {
-                        tracing::info!("agent {}: settings discovery started", spec.id);
-                        let discovered = if spec.driver == provider::Driver::Acp {
-                            acp::discover::run(&shared, &spec).await.map(|_| None)
-                        } else if spec.driver == provider::Driver::Claude {
-                            native::claude::discover(spec.clone(), shared.paths.project_root.clone()).await.map(Some)
-                        } else {
-                            return;
-                        };
-                        if let Ok(Some(found)) = discovered {
-                            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, &levels);
-                            })
-                            .await;
-                        } else if let Err(e) = discovered {
-                            tracing::info!("agent {}: settings discovery failed: {e}", spec.id);
-                        }
-                        let _ = done.send(true);
-                    });
-                    ready
-                })
-                .clone()
-        };
-        while !*ready.borrow_and_update() {
-            if ready.changed().await.is_err() {
-                break;
-            }
-        }
-    }
-
-    fn has_config(&self, provider: &str) -> bool {
-        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 };
-        let models: Vec<&str> = known
-            .config
-            .iter()
-            .filter(|o| o.category.as_deref() == Some("model"))
-            .flat_map(|o| o.values.iter().map(|v| v.value.as_str()))
-            .collect();
-        // No advertised models yet: nothing to attach effort levels to.
-        if models.is_empty() {
-            return false;
-        }
-        models.iter().all(|id| known.thought_levels.contains_key(*id))
-    }
-
    fn root_key(&self) -> String {
        self.paths.project_root.to_string_lossy().into_owned()
    }
@@ -283,78 +223,48 @@ impl Shared {
        commands: Option<&[AgentCommand]>,
        model: Option<&str>,
    ) {
-        self.remember_inner(provider, config, commands, model, &[], false);
-    }
-
-    /// `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(
-        &self,
-        provider: &str,
-        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()) {
+        // Running tasks retain their own reported settings. Once discovery has
+        // succeeded, a session's older list/defaults cannot change New Task choices.
+        if !known.authoritative
+            && let Some(config) = config.filter(|c| !c.is_empty())
+        {
            if let Some(model) = model {
                let levels: Vec<_> =
-                    c.iter().filter(|o| o.category.as_deref() == Some("thought_level")).cloned().collect();
+                    config.iter().filter(|o| o.category.as_deref() == Some("thought_level")).cloned().collect();
                if known.thought_levels.get(model) != Some(&levels) {
                    known.thought_levels.insert(model.to_owned(), levels);
                    changed = true;
                }
            }
-            if !c.is_empty() && known.config != c {
-                known.config = c.to_vec();
+            if known.config != config {
+                known.config = config.to_vec();
                changed = true;
            }
        }
-        let root = self.root_key();
-        if let Some(c) = commands.filter(|c| {
-            !c.is_empty()
-                && (!discovered || known.commands.get(&root).is_none_or(Vec::is_empty))
-                && known.commands.get(&root).map(Vec::as_slice) != Some(c)
-        }) {
-            known.commands.insert(root, c.to_vec());
+        if let Some(commands) = commands.filter(|c| !c.is_empty())
+            && known.commands.get(&self.root_key()).map(Vec::as_slice) != Some(commands)
+        {
+            known.commands.insert(self.root_key(), commands.to_vec());
            changed = true;
        }
-        if !changed {
-            return;
+        if changed {
+            self.persist_known(&cache);
        }
-        if let Ok(bytes) = serde_json::to_vec_pretty(&*cache)
+        drop(cache);
+        if changed {
+            self.emit(AgentEvent::Providers);
+        }
+    }
+
+    fn persist_known(&self, cache: &HashMap<String, Known>) {
+        if let Ok(bytes) = serde_json::to_vec_pretty(cache)
            && let Err(e) = write_file(&self.paths.models_file, &bytes)
        {
            tracing::warn!("saving agent settings: {e}");
        }
-        // The cached provider config actually changed (a session report, discovery,
-        // or a turn update): tell subscribers to re-list, so a changed model list
-        // reaches the composer without waiting for the next task (#1490). Unchanged
-        // reports stay silent, so routine session traffic emits nothing. The cache
-        // lock is released first; the sink never runs under it.
-        drop(cache);
-        self.emit(AgentEvent::Providers);
    }
 }

@@ -469,8 +379,7 @@ impl AgentManager {
    }

    fn with_connector(paths: AgentPaths, runtime: tokio::runtime::Handle, connector: Connector) -> Self {
-        let known =
-            std::fs::read(&paths.models_file).ok().and_then(|b| serde_json::from_slice(&b).ok()).unwrap_or_default();
+        let known = paths.catalogs.store(&paths.models_file);
        let providers = RwLock::new(provider::load(paths.custom_agents_dir.as_deref(), paths.env_secrets.as_deref()));
        let shared = Arc::new(Shared {
            paths,
@@ -479,13 +388,13 @@ impl AgentManager {
            sink: RwLock::new(None),
            security: RwLock::new(None),
            new_task_approvals: RwLock::new(None),
-            known: Mutex::new(known),
+            known,
            providers,
            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),
        });
+        shared.paths.catalogs.subscribe(&shared);
        let mut tasks = HashMap::new();
        for file in std::fs::read_dir(&shared.paths.store_dir).into_iter().flatten().flatten() {
            let path = file.path();
@@ -542,9 +451,9 @@ impl AgentManager {
            .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);
-                info.thought_levels =
-                    self.shared.known.lock().get(&p.id).map(|k| k.thought_levels.clone()).unwrap_or_default();
+                let catalog = self.shared.paths.catalogs.cached(&self.shared, &p.id);
+                info.config = self.shared.config_for_new_task(catalog.config, &p.id);
+                info.thought_levels = catalog.thought_levels;
                info.commands = self.shared.known_commands(&p.id);
                info
            })
@@ -632,17 +541,20 @@ 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) || !self.shared.knows_all_levels(&provider))
-            && let Some(spec) = self
-                .shared
-                .spec(&provider)
-                .filter(|s| matches!(s.driver, provider::Driver::Claude | provider::Driver::Acp))
+            && let Some(spec) =
+                provider::load(self.shared.paths.custom_agents_dir.as_deref(), self.shared.env_secrets())
+                    .into_iter()
+                    .find(|spec| spec.id == provider)
        {
-            let claude = spec.driver == provider::Driver::Claude;
-            self.shared.fetch_settings(spec).await;
-            if claude {
-                offered = self.shared.known_commands(&provider);
+            let (_, flight) = self.shared.paths.catalogs.request(&self.shared, spec, false);
+            if let Some(mut ready) = flight {
+                while !*ready.borrow_and_update() {
+                    if ready.changed().await.is_err() {
+                        break;
+                    }
+                }
            }
+            offered = self.shared.known_commands(&provider);
        }
        for &(name, description) in builtin_commands(&provider) {
            if !offered.iter().any(|c| c.name == name) {
@@ -794,16 +706,18 @@ impl AgentManager {
            }
        };
        // Until the session reports its own, show what the agent offered last time with the choices applied.
-        let mut config = self.shared.known_config(&spec.id);
+        let catalog = self.shared.paths.catalogs.cached(&self.shared, &spec.id);
+        let mut levels = catalog.thought_levels;
+        let mut config = self.shared.config_for_new_task(catalog.config, &spec.id);
        for choice in &req.config {
            if let Some(o) = config.iter_mut().find(|o| o.id == choice.id) {
                o.current = Some(choice.value.clone());
            }
        }
        if let Some(model) = model_of(&config)
-            && let Some(levels) = self.shared.known.lock().get(&spec.id).and_then(|k| k.thought_levels.get(&model))
+            && let Some(levels) = levels.remove(&model)
        {
-            config.extend(levels.iter().cloned().map(|mut o| {
+            config.extend(levels.into_iter().map(|mut o| {
                if let Some(choice) =
                    req.config.iter().find(|c| c.id == o.id && o.values.iter().any(|v| v.value == c.value))
                {
@@ -538,6 +538,19 @@ pub struct AgentChanges {
    pub commits: Vec<AgentCommit>,
 }

+/// Authoritative choices for new tasks, independent of any running session's settings.
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct AgentModelCatalog {
+    pub provider: String,
+    pub config: Vec<AgentConfigOption>,
+    pub thought_levels: BTreeMap<String, Vec<AgentConfigOption>>,
+    pub refreshing: bool,
+    pub refreshed_at_ms: Option<f64>,
+    pub retry_at_ms: Option<f64>,
+    pub error: Option<String>,
+}
+
 /// Streamed to the window that subscribed (`AgentManager::subscribe`).
 #[derive(Clone, Debug, Serialize, Type)]
 #[serde(tag = "type", rename_all = "camelCase", rename_all_fields = "camelCase")]
@@ -575,6 +588,10 @@ pub enum AgentEvent {
        provider: String,
        limits: Vec<AgentLimit>,
    },
+    /// A model lookup started or completed, including unsuccessful lookups.
+    ModelCatalog {
+        catalog: AgentModelCatalog,
+    },
    /// The installed or configured agent providers changed.
    Providers,
 }
@@ -85,6 +85,8 @@ pub(crate) async fn discover(spec: ProviderSpec, cwd: PathBuf) -> Result<Discove
        let (spec, cwd) = spec.await.map_err(|e| e.to_string())?;
        let mut args = spec.args;
        args.extend(Start::New { id: uuid::Uuid::new_v4().to_string() }.args());
+        // Metadata discovery must not launch project-configured MCP servers.
+        args.extend(["--strict-mcp-config".into(), "--mcp-config".into(), "{\"mcpServers\":{}}".into()]);
        let launch = Launch { program: spec.command, args, cwd, env: spec.env };
        let mut io = cli::Process.launch(&launch, Arc::new(|_| {})).map_err(|e| e.to_string())?;
        let _stop = io.kill.clone().drop_guard();
@@ -44,6 +44,92 @@ pub(crate) fn connect(
    })
 }

+/// A model lookup uses app-server directly: no thread, task, prompt or project MCP.
+pub(crate) async fn discover(
+    spec: ProviderSpec,
+    cwd: std::path::PathBuf,
+) -> Result<crate::catalogs::Discovered, String> {
+    let spec = tokio::task::spawn_blocking({
+        let cwd = cwd.clone();
+        move || spec.resolve_for_launch(&cwd)
+    })
+    .await
+    .map_err(|e| e.to_string())?;
+    let peer = Peer::spawn_framed(
+        &spec.command,
+        &spec.args,
+        &cwd,
+        &spec.env,
+        Arc::new(ide_jsonrpc::NoopHandler),
+        Box::new(|_| {}),
+        Framing::Lines,
+    )
+    .map_err(|e| e.to_string())?;
+    let _stop = crate::catalogs::KillPeer(peer.clone());
+    tokio::time::timeout(Duration::from_secs(30), async {
+        let _: Value = peer.request("initialize", initialize_params(), None).await.map_err(|e| e.to_string())?;
+        peer.notify("initialized", Value::Null).map_err(|e| e.to_string())?;
+        let mut models = list_models(&peer).await.map_err(|e| e.message)?;
+        models.retain(|model| !model.hidden);
+        let mut settings = Settings::of(&json!({}), &models);
+        if settings.model.is_empty()
+            && let Some(model) = models.first()
+        {
+            settings.model = model.id.clone();
+            settings.fit_effort(&models);
+        }
+        let options = translate::config_options(&models, &settings);
+        let config = crate::config::options_of(&json!({ "configOptions": options }));
+        let levels = models
+            .iter()
+            .map(|model| {
+                let mut settings = settings.clone();
+                settings.model = model.id.clone();
+                settings.fit_effort(&models);
+                let options = translate::config_options(&models, &settings);
+                let levels = crate::config::options_of(&json!({ "configOptions": options }))
+                    .into_iter()
+                    .filter(|o| o.category.as_deref() == Some("thought_level"))
+                    .collect();
+                (model.id.clone(), levels)
+            })
+            .collect();
+        Ok(crate::catalogs::Discovered { config, commands: None, levels })
+    })
+    .await
+    .map_err(|_| "Codex model discovery timed out".to_owned())?
+}
+
+fn initialize_params() -> Value {
+    json!({
+        "clientInfo": { "name": "openidea", "title": "OpenIDEA", "version": env!("CARGO_PKG_VERSION") },
+        "capabilities": { "experimentalApi": true, "optOutNotificationMethods": OPT_OUT },
+    })
+}
+
+async fn list_models(peer: &Peer) -> Result<Vec<ModelInfo>, ResponseError> {
+    let mut all = Vec::new();
+    let mut cursor = Value::Null;
+    let mut seen = HashSet::new();
+    loop {
+        let page: Value = peer.request("model/list", json!({ "cursor": cursor }), None).await.map_err(from_codex)?;
+        let Some(data) = page.get("data").and_then(Value::as_array) else {
+            return Err(error(codes::INTERNAL_ERROR, "Codex returned an invalid model list"));
+        };
+        let models = translate::models_of(&page);
+        if models.len() != data.len() {
+            return Err(error(codes::INTERNAL_ERROR, "Codex returned an invalid model list"));
+        }
+        all.extend(models);
+        match page.get("nextCursor") {
+            None | Some(Value::Null) => return Ok(all),
+            Some(Value::String(next)) if next.is_empty() => return Ok(all),
+            Some(Value::String(next)) if seen.insert(next.clone()) => cursor = json!(next),
+            _ => return Err(error(codes::INTERNAL_ERROR, "Codex returned an invalid model-list cursor")),
+        }
+    }
+}
+
 /// Connects `client` to a shim driving the codex connection `connect_codex` opens (it
 /// gets the handler for what codex sends). Each side's end closes the other.
 fn attach(
@@ -250,15 +336,7 @@ impl CodexShim {
    }

    async fn initialize(&self) -> Result<Value, ResponseError> {
-        let info = self
-            .call(
-                "initialize",
-                json!({
-                    "clientInfo": { "name": "openidea", "title": "OpenIDEA", "version": env!("CARGO_PKG_VERSION") },
-                    "capabilities": { "experimentalApi": true, "optOutNotificationMethods": OPT_OUT },
-                }),
-            )
-            .await?;
+        let info = self.call("initialize", initialize_params()).await?;
        self.codex().notify("initialized", Value::Null).map_err(from_codex)?;
        self.state.lock().initialized = true;
        // `<client>/<codex version> (<platform>) …`
@@ -282,32 +360,15 @@ impl CodexShim {
        }))
    }

-    /// The models codex offers; empty when it can't list them.
-    async fn models(&self) -> Arc<Vec<ModelInfo>> {
+    /// Cache only complete, successful listings; a failed page must never become availability.
+    async fn models(&self) -> Result<Arc<Vec<ModelInfo>>, ResponseError> {
        let mut cached = self.models.lock().await;
-        if let Some(m) = cached.as_ref() {
-            return m.clone();
+        if let Some(models) = cached.as_ref() {
+            return Ok(models.clone());
        }
-        let mut all = Vec::new();
-        let mut cursor = Value::Null;
-        loop {
-            match self.call("model/list", json!({ "cursor": cursor })).await {
-                Ok(page) => {
-                    all.extend(translate::models_of(&page));
-                    match page.get("nextCursor").filter(|c| c.is_string()) {
-                        Some(next) if *next != cursor => cursor = next.clone(),
-                        _ => break,
-                    }
-                }
-                Err(e) => {
-                    tracing::warn!("codex: listing models failed: {}", e.message);
-                    return Arc::new(all);
-                }
-            }
-        }
-        let models = Arc::new(all);
+        let models = Arc::new(list_models(self.codex()).await?);
        *cached = Some(models.clone());
-        models
+        Ok(models)
    }

    async fn publish_skills(&self, session: &str) {
@@ -341,7 +402,7 @@ impl CodexShim {
    }

    async fn new_session(&self, params: &Value) -> Result<Value, ResponseError> {
-        let models = self.models().await;
+        let models = self.models().await?;
        let mut request = json!({ "cwd": params.get("cwd") });
        if let Some(config) = translate::mcp_config(params) {
            request["config"] = config;
@@ -358,7 +419,7 @@ impl CodexShim {
    /// Resumes the thread and replays its history before answering.
    async fn load_session(&self, params: &Value) -> Result<Value, ResponseError> {
        let id = str_param(params, "sessionId")?;
-        let models = self.models().await;
+        let models = self.models().await?;
        let mut request = json!({ "threadId": id, "cwd": params.get("cwd") });
        if let Some(config) = translate::mcp_config(params) {
            request["config"] = config;
@@ -376,7 +437,7 @@ impl CodexShim {

    async fn fork_session(&self, params: &Value) -> Result<Value, ResponseError> {
        let source = str_param(params, "sessionId")?;
-        let models = self.models().await;
+        let models = self.models().await?;
        let settings = self.state.lock().threads.get(source).and_then(|t| t.settings.clone());
        let mut request = json!({ "threadId": source, "cwd": params.get("cwd") });
        if let Some(config) = translate::mcp_config(params) {
@@ -397,7 +458,7 @@ impl CodexShim {
        let session = str_param(params, "sessionId")?;
        let option = str_param(params, "configId")?;
        let value = str_param(params, "value")?;
-        let models = self.models().await;
+        let models = self.models().await?;
        let mut state = self.state.lock();
        let settings = state
            .threads
@@ -414,7 +475,7 @@ impl CodexShim {
        if input.is_empty() {
            return Err(invalid("empty prompt"));
        }
-        let models = self.models().await;
+        let models = self.models().await?;
        let (done, ended) = oneshot::channel();
        let settings = {
            let mut state = self.state.lock();
@@ -11,6 +11,155 @@ use std::collections::VecDeque;
 use std::path::PathBuf;
 use tokio::io::{AsyncBufReadExt, AsyncRead, AsyncWrite, AsyncWriteExt, BufReader};

+struct ModelPages {
+    pages: Mutex<VecDeque<Result<Value, (i64, String)>>>,
+    cursors: Mutex<Vec<Value>>,
+}
+
+impl Handler for ModelPages {
+    fn on_notification(&self, _: &str, _: Value) {}
+
+    fn on_request(&self, method: &str, params: Value) -> Result<Value, (i64, String)> {
+        assert_eq!(method, "model/list", "listing models must never start a thread or turn");
+        self.cursors.lock().push(params["cursor"].clone());
+        self.pages.lock().pop_front().expect("another expected page")
+    }
+}
+
+fn model_peer(pages: Arc<ModelPages>) -> (Peer, Peer) {
+    let (ours, theirs) = tokio::io::duplex(1 << 16);
+    let (read, write) = tokio::io::split(theirs);
+    let server = Peer::connect_framed(read, write, pages, Framing::Lines);
+    let (read, write) = tokio::io::split(ours);
+    (Peer::connect_framed(read, write, Arc::new(ide_jsonrpc::NoopHandler), Framing::Lines), server)
+}
+
+#[tokio::test]
+async fn model_pagination_failure_does_not_cache_an_incomplete_catalog() {
+    let first = json!({ "data": [{ "id": "first" }], "nextCursor": "next" });
+    let pages = Arc::new(ModelPages {
+        pages: Mutex::new(VecDeque::from([
+            Ok(first.clone()),
+            Err((-32000, "authentication expired".into())),
+            Ok(first),
+            Ok(json!({ "data": [{ "id": "second" }], "nextCursor": null })),
+        ])),
+        cursors: Mutex::default(),
+    });
+    let (peer, server) = model_peer(pages.clone());
+    let shim = CodexShim {
+        runtime: tokio::runtime::Handle::current(),
+        codex: OnceLock::from(peer.clone()),
+        client: OnceLock::new(),
+        state: Mutex::default(),
+        models: tokio::sync::Mutex::new(None),
+        skills: tokio::sync::Mutex::new(()),
+    };
+    assert_eq!(shim.models().await.unwrap_err().message, "authentication expired");
+    let models = shim.models().await.unwrap();
+    assert_eq!(models.iter().map(|m| m.id.as_str()).collect::<Vec<_>>(), ["first", "second"]);
+    assert_eq!(shim.models().await.unwrap().len(), 2);
+    assert_eq!(*pages.cursors.lock(), [Value::Null, json!("next"), Value::Null, json!("next")]);
+    peer.kill();
+    server.kill();
+}
+
+#[tokio::test]
+async fn repeated_or_invalid_model_cursors_and_malformed_pages_are_failures() {
+    for pages in [
+        vec![json!({ "data": [], "nextCursor": "a" }), json!({ "data": [], "nextCursor": "a" })],
+        vec![
+            json!({ "data": [], "nextCursor": "a" }),
+            json!({ "data": [], "nextCursor": "b" }),
+            json!({ "data": [], "nextCursor": "a" }),
+        ],
+        vec![json!({ "data": [], "nextCursor": 7 })],
+        vec![json!({ "nextCursor": null })],
+        vec![json!({ "data": [{}], "nextCursor": null })],
+    ] {
+        let pages =
+            Arc::new(ModelPages { pages: Mutex::new(pages.into_iter().map(Ok).collect()), cursors: Mutex::default() });
+        let (peer, server) = model_peer(pages);
+        assert!(list_models(&peer).await.is_err());
+        peer.kill();
+        server.kill();
+    }
+}
+
+#[cfg(unix)]
+#[tokio::test(flavor = "multi_thread")]
+async fn native_discovery_only_initializes_and_pages_models_then_stops_the_process() {
+    use std::os::unix::fs::PermissionsExt;
+    let tmp = tempfile::tempdir().unwrap();
+    let script = tmp.path().join("fake-codex");
+    std::fs::write(
+        &script,
+        r#"#!/usr/bin/env python3
+import json, os, pathlib, sys
+pathlib.Path('pid').write_text(str(os.getpid()))
+for line in sys.stdin:
+    request = json.loads(line)
+    with pathlib.Path('requests').open('a') as f:
+        f.write(json.dumps(request) + '\n')
+    method = request['method']
+    if method == 'initialized':
+        continue
+    if method == 'initialize':
+        result = {}
+    elif method == 'model/list':
+        cursor = request['params']['cursor']
+        model = 'one' if cursor is None else 'two'
+        result = {'data': [{'id': model, 'isDefault': cursor is None,
+            'defaultReasoningEffort': 'low', 'supportedReasoningEfforts': [{'reasoningEffort': 'low'}]}],
+            'nextCursor': 'second-page' if cursor is None else None}
+    else:
+        raise RuntimeError('must not create a thread or prompt: ' + method)
+    print(json.dumps({'jsonrpc': '2.0', 'id': request['id'], 'result': result}), flush=True)
+"#,
+    )
+    .unwrap();
+    std::fs::set_permissions(&script, std::fs::Permissions::from_mode(0o755)).unwrap();
+    let spec = ProviderSpec {
+        id: "codex".into(),
+        name: "Codex".into(),
+        driver: crate::provider::Driver::Codex,
+        command: script.to_string_lossy().into_owned(),
+        args: Vec::new(),
+        env: Vec::new(),
+        login_hint: String::new(),
+        source: crate::AgentSource::Builtin,
+    };
+    let found = discover(spec, tmp.path().to_path_buf()).await.unwrap();
+    let models: Vec<_> = found
+        .config
+        .iter()
+        .filter(|o| o.category.as_deref() == Some("model"))
+        .flat_map(|o| o.values.iter().map(|v| v.value.as_str()))
+        .collect();
+    assert_eq!(models, ["one", "two"]);
+    assert_eq!(found.levels.keys().map(String::as_str).collect::<Vec<_>>(), ["one", "two"]);
+    let requests = std::fs::read_to_string(tmp.path().join("requests")).unwrap();
+    let requests: Vec<Value> = requests.lines().map(|line| serde_json::from_str(line).unwrap()).collect();
+    assert_eq!(
+        requests.iter().map(|r| r["method"].as_str().unwrap()).collect::<Vec<_>>(),
+        ["initialize", "initialized", "model/list", "model/list"]
+    );
+    assert_eq!(requests[2]["params"]["cursor"], Value::Null);
+    assert_eq!(requests[3]["params"]["cursor"], "second-page");
+    let pid = std::fs::read_to_string(tmp.path().join("pid")).unwrap();
+    tokio::time::timeout(Duration::from_secs(5), async {
+        loop {
+            let alive = std::process::Command::new("kill").args(["-0", pid.trim()]).output().unwrap().status.success();
+            if !alive {
+                break;
+            }
+            tokio::time::sleep(Duration::from_millis(10)).await;
+        }
+    })
+    .await
+    .expect("discovery must kill and reap its child");
+}
+
 // ---- Pure translations -------------------------------------------------------------

 fn models() -> Vec<ModelInfo> {
@@ -120,10 +120,18 @@ impl ProviderSpec {
    }

    /// Resolve once before connecting, so authentication guidance names that same install.
-    pub(crate) fn resolve_for_launch(mut self, cwd: &Path) -> Self {
+    pub(crate) fn resolve_for_launch(self, cwd: &Path) -> Self {
+        let strip = prefer_stored_copilot_auth();
+        self.resolve_for_launch_with_copilot_env(cwd, strip)
+    }
+
+    pub(crate) fn resolve_for_launch_with_copilot_env(mut self, cwd: &Path, strip_ambient_tokens: bool) -> Self {
        if self.driver != Driver::Acp {
            self.command = crate::native::newest_install(&self.command);
        }
+        if is_copilot_provider(&self.id) {
+            self.env = sanitized_copilot_env(&self.env, strip_ambient_tokens);
+        }
        let program = ide_jsonrpc::resolve_spawn_program(&self.command, &self.env);
        self.command =
            if program.components().count() > 1 && !program.is_absolute() { cwd.join(program) } else { program }
@@ -133,6 +141,69 @@ impl ProviderSpec {
    }
 }

+const AMBIENT_COPILOT_AUTH_VARS: [&str; 3] = ["COPILOT_GITHUB_TOKEN", "GH_TOKEN", "GITHUB_TOKEN"];
+static PREFER_STORED_COPILOT_AUTH: std::sync::atomic::AtomicBool = std::sync::atomic::AtomicBool::new(false);
+
+pub(crate) fn is_copilot_provider(id: &str) -> bool {
+    id == "copilot" || id.starts_with("copilot-")
+}
+
+pub(crate) fn prefer_stored_copilot_auth() -> bool {
+    PREFER_STORED_COPILOT_AUTH.load(std::sync::atomic::Ordering::Acquire)
+}
+
+pub(crate) fn mark_prefer_stored_copilot_auth() {
+    PREFER_STORED_COPILOT_AUTH.store(true, std::sync::atomic::Ordering::Release);
+}
+
+pub(crate) fn has_unconfigured_copilot_ambient_token(spec_env: &[(String, String)]) -> bool {
+    AMBIENT_COPILOT_AUTH_VARS.iter().any(|&key| {
+        !spec_env.iter().any(|(k, v)| k == key && !v.is_empty())
+            && ambient_copilot_env_value(key).is_some_and(|v| !v.is_empty())
+    })
+}
+
+fn ambient_copilot_env_value(key: &str) -> Option<String> {
+    ide_core::process::shell_env()
+        .find(|(k, _)| *k == key)
+        .map(|(_, v)| v.to_string_lossy().into_owned())
+        .or_else(|| ide_core::process::host_var_os(key).map(|v| v.to_string_lossy().into_owned()))
+}
+
+/// Builds child environment overrides for `copilot`:
+/// - Always clears ambient classic PATs (`ghp_…`), which Copilot CLI unconditionally rejects
+///   (`"Classic PATs are not supported"`) instead of falling back to Keychain / `gh` login.
+/// - When `strip_ambient_tokens` is true, clears unconfigured ambient `GITHUB_TOKEN` / `GH_TOKEN` /
+///   `COPILOT_GITHUB_TOKEN` so Copilot uses its stored login (`~/.copilot` or `gh auth` keyring),
+///   while preserving any token explicitly configured in OpenIDEA's agent `spec_env`.
+pub(crate) fn sanitized_copilot_env(
+    spec_env: &[(String, String)],
+    strip_ambient_tokens: bool,
+) -> Vec<(String, String)> {
+    sanitize_copilot_env_with(spec_env, strip_ambient_tokens, ambient_copilot_env_value)
+}
+
+pub(crate) fn sanitize_copilot_env_with(
+    spec_env: &[(String, String)],
+    strip_ambient_tokens: bool,
+    lookup: impl Fn(&str) -> Option<String>,
+) -> Vec<(String, String)> {
+    let mut out = Vec::with_capacity(spec_env.len() + AMBIENT_COPILOT_AUTH_VARS.len());
+    for key in AMBIENT_COPILOT_AUTH_VARS {
+        let explicit = spec_env.iter().any(|(k, v)| k == key && !v.is_empty());
+        if explicit {
+            continue;
+        }
+        if let Some(val) = lookup(key).filter(|v| !v.is_empty())
+            && (strip_ambient_tokens || val.trim().starts_with("ghp_"))
+        {
+            out.push((key.to_owned(), String::new()));
+        }
+    }
+    out.extend(spec_env.iter().cloned());
+    out
+}
+
 fn render_login_hint(spec: &ProviderSpec, program: &Path, on_path: Option<&Path>, windows: bool) -> String {
    let Some(builtin) = builtin_spec(&spec.id) else { return spec.login_hint.clone() };
    let prefix = format!("Run `{}", builtin.command);
@@ -1101,4 +1172,23 @@ mod tests {
        import_acp(dir.path(), None, "not json").unwrap_err();
        assert!(import_acp(dir.path(), None, "{}").unwrap().is_empty());
    }
+
+    #[test]
+    fn sanitizes_classic_pats_and_ambient_tokens_while_preserving_explicit_agent_env() {
+        let lookup = |k: &str| match k {
+            "GITHUB_TOKEN" => Some("ghp_classic_pat_123".into()),
+            "GH_TOKEN" => Some("gho_oauth_token_456".into()),
+            _ => None,
+        };
+        assert_eq!(sanitize_copilot_env_with(&[], false, lookup), vec![("GITHUB_TOKEN".into(), String::new())]);
+        assert_eq!(
+            sanitize_copilot_env_with(&[], true, lookup),
+            vec![("GH_TOKEN".into(), String::new()), ("GITHUB_TOKEN".into(), String::new())]
+        );
+        let explicit = vec![("GH_TOKEN".into(), "github_pat_custom".into())];
+        assert_eq!(
+            sanitize_copilot_env_with(&explicit, true, lookup),
+            vec![("GITHUB_TOKEN".into(), String::new()), ("GH_TOKEN".into(), "github_pat_custom".into())]
+        );
+    }
 }
@@ -25,6 +25,7 @@ fn paths(dir: &Path) -> AgentPaths {
        custom_agents_dir: None,
        home_dir: None,
        env_secrets: None,
+        catalogs: Arc::default(),
    }
 }

@@ -405,6 +405,7 @@ fn manager_at(dir: &Path, models_file: &Path, agent: Arc<FakeAgent>) -> AgentMan
            // user's profile, when temp lives under it) leaks into the test.
            home_dir: Some(dir.to_path_buf()),
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
        connector,
@@ -442,7 +443,7 @@ async fn saved_conversation_reads_do_not_start_or_load_the_agent() {

 #[cfg(unix)]
 #[tokio::test(flavor = "multi_thread")]
-async fn claude_commands_before_session_are_fetched_once_and_saved() {
+async fn claude_commands_share_catalog_discovery_and_persist_results() {
    use std::os::unix::fs::PermissionsExt;

    for outcome in ["success", "session_report", "empty", "settings_timeout", "error", "exit", "timeout", "missing"] {
@@ -502,14 +503,18 @@ for line in sys.stdin:
        std::fs::write(root.join(".claude/skills/triage/SKILL.md"), "---\nname: triage\ndescription: Triage\n---\n")
            .unwrap();
        let mgr = manager(root, Arc::new(FakeAgent::default()));
-        {
-            let mut providers = mgr.shared.providers.write();
-            let spec = providers.iter_mut().find(|p| p.id == "claude").unwrap();
-            if outcome != "missing" {
-                spec.command = script.to_string_lossy().into_owned();
-            }
-            spec.env = vec![("OUTCOME".into(), outcome.into())];
+        if outcome != "missing" {
+            provider::set_builtin_command(&root.join("agents"), None, "claude", Some(&script.to_string_lossy()))
+                .unwrap();
        }
+        provider::set_builtin_env(
+            &root.join("agents"),
+            None,
+            "claude",
+            BTreeMap::from([("OUTCOME".into(), outcome.into())]),
+        )
+        .unwrap();
+        mgr.reload_providers();
        let concurrent = async {
            if outcome == "session_report" {
                tokio::time::timeout(Duration::from_secs(10), async {
@@ -553,7 +558,6 @@ for line in sys.stdin:
                    effort.unwrap().current.as_deref(),
                    Some(match outcome {
                        "settings_timeout" => "default",
-                        "session_report" => "low",
                        _ => "high",
                    })
                );
@@ -571,6 +575,8 @@ for line in sys.stdin:
            assert_eq!(launches.lines().count(), 1, "{outcome}");
            let args: Vec<String> = serde_json::from_str(launches.trim()).unwrap();
            assert!(args.windows(2).any(|a| a == ["--input-format", "stream-json"]));
+            assert!(args.iter().any(|a| a == "--strict-mcp-config"));
+            assert!(args.windows(2).any(|a| a == ["--mcp-config", "{\"mcpServers\":{}}"]));
            let requests = std::fs::read_to_string(root.join("requests")).unwrap();
            let subtypes: Vec<String> = requests
                .lines()
@@ -1431,6 +1437,7 @@ async fn real_claude_task_in_a_worktree() {
            custom_agents_dir: None,
            home_dir: None,
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
    );
@@ -2265,6 +2272,7 @@ async fn reload_providers_updates_registry_install_clears_stale_probes_and_notif
            custom_agents_dir: Some(agents_dir.clone()),
            home_dir: None,
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
        connector,
@@ -2597,6 +2605,7 @@ async fn delete_running_agent(no_load: bool) {
            custom_agents_dir: None,
            home_dir: None,
            env_secrets: None,
+            catalogs: Arc::default(),
        },
        tokio::runtime::Handle::current(),
        connector,
@@ -2659,34 +2668,6 @@ fn mcp_servers_follow_server_state_and_agent_capabilities() {
    );
 }

-#[tokio::test(flavor = "multi_thread")]
-async fn session_settings_win_over_discovery_in_memory_and_on_disk() {
-    for discovery_first in [false, true] {
-        let tmp = tempfile::tempdir().unwrap();
-        let mgr = manager(tmp.path(), Arc::new(FakeAgent::default()));
-        let options = |model: &str, effort: &str| {
-            config::options_of(&json!({ "configOptions": [
-                { "id": "model", "category": "model", "type": "select", "currentValue": model,
-                  "options": [{ "value": "saved" }, { "value": "discovered" }] },
-                { "id": "effort", "category": "thought_level", "type": "select", "currentValue": effort,
-                  "options": [{ "value": "low" }, { "value": "high" }] }
-            ] }))
-        };
-        let saved = options("saved", "low");
-        let discovered = options("discovered", "high");
-        if discovery_first {
-            mgr.shared.remember_discovered("claude", &discovered, &[], &[]);
-        }
-        mgr.shared.remember("claude", Some(&saved), None, Some("saved"));
-        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"));
-            assert_eq!(mgr.shared.known.lock()["claude"].thought_levels["saved"], saved[1..]);
-        }
-    }
-}
-
 #[tokio::test(flavor = "multi_thread")]
 async fn provider_reload_does_not_start_acp_discovery() {
    let agent = Arc::new(FakeAgent::default());
@@ -2773,31 +2754,6 @@ async fn discovery_times_out_when_session_new_hangs() {
    assert!(!cursor.config.iter().any(|o| o.category.as_deref() == Some("model")));
 }

-#[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();
@@ -53,6 +53,8 @@ pub enum BuildSystem {
    TypeScript,
    #[serde(rename = "cmake")]
    CMake,
+    #[serde(rename = "dotnet")]
+    Dotnet,
 }

 /// One command of a build.
@@ -165,6 +167,8 @@ fn detect_dir(dir: &Path, model: &BuildModel, root: &Path) -> Option<BuildSystem
        || has(dir, &["build.gradle", "build.gradle.kts", "settings.gradle", "settings.gradle.kts"])
    {
        Some(BuildSystem::Gradle)
+    } else if dotnet_target(dir).is_some() {
+        Some(BuildSystem::Dotnet)
    } else if has(dir, &["Cargo.toml"]) {
        Some(BuildSystem::Cargo)
    } else if has(dir, &["go.mod", "go.work"]) {
@@ -225,7 +229,7 @@ pub fn plan(
        .or((!model.gradle.is_empty()).then_some(BuildSystem::Gradle))
        .or_else(|| model.maven.as_ref().filter(|m| !m.projects.is_empty()).map(|_| BuildSystem::Maven))
        .ok_or_else(|| {
-            IdeError::not_found("no supported build system (Maven, Gradle, Cargo, Go, TypeScript, CMake) found")
+            IdeError::not_found("no supported build system (Maven, Gradle, .NET, Cargo, Go, TypeScript, CMake) found")
        })?;
    let module = module_dir.as_deref().filter(|d| *d != root);
    let title = match module {
@@ -244,6 +248,7 @@ pub fn plan(
        BuildSystem::Go => go_steps(file.and_then(Path::parent).unwrap_or(&dir), kind)?,
        BuildSystem::TypeScript => ts_steps(&dir, kind),
        BuildSystem::CMake => cmake_steps(&dir, kind, cmake.and_then(<[_]>::first)),
+        BuildSystem::Dotnet => dotnet_steps(&dir, kind)?,
    };
    Ok(BuildPlan { system, title, steps })
 }
@@ -451,6 +456,33 @@ fn has_build_script(dir: &Path) -> bool {
        .is_some_and(|v| v.pointer("/scripts/build").is_some_and(serde_json::Value::is_string))
 }

+/// The solution (`.sln` / `.slnx`) or project (`.csproj` / `.fsproj` / `.vbproj`) file `dir`
+/// builds: a solution first, then a project; the first by name when there are several.
+fn dotnet_target(dir: &Path) -> Option<PathBuf> {
+    let mut files: Vec<PathBuf> =
+        std::fs::read_dir(dir).ok()?.flatten().map(|e| e.path()).filter(|p| p.is_file()).collect();
+    files.sort();
+    let ext = |p: &Path| p.extension().map(|e| e.to_string_lossy().to_ascii_lowercase()).unwrap_or_default();
+    let solution = files.iter().find(|p| matches!(ext(p).as_str(), "sln" | "slnx"));
+    solution.or_else(|| files.iter().find(|p| matches!(ext(p).as_str(), "csproj" | "fsproj" | "vbproj"))).cloned()
+}
+
+/// `dotnet build` of the directory's solution or project; Rebuild skips incremental builds,
+/// Build Artifacts publishes. The summary that repeats every message is left out.
+fn dotnet_steps(dir: &Path, kind: BuildKind) -> IdeResult<Vec<BuildStep>> {
+    let target = dotnet_target(dir).ok_or_else(|| IdeError::not_found("no .NET solution or project found"))?;
+    let target = target.file_name().map_or_else(String::new, |n| n.to_string_lossy().into_owned());
+    let verb = if kind == BuildKind::Artifacts { "publish" } else { "build" };
+    let mut step = BuildStep::new("dotnet", &[verb, &target, "-nologo", "-clp:NoSummary"], dir, Format::Msbuild);
+    if kind == BuildKind::Rebuild {
+        step.args.push("--no-incremental".into());
+    }
+    // The classic console logger prints the canonical `file(line,col): error` lines; the
+    // terminal logger (.NET 8+) only appears on a terminal, but rules it out for older SDKs too.
+    step.env.insert("MSBUILDTERMINALLOGGER".into(), "off".into());
+    Ok(vec![step])
+}
+
 fn ts_steps(dir: &Path, kind: BuildKind) -> Vec<BuildStep> {
    let script = has_build_script(dir);
    if script && (kind == BuildKind::Artifacts || !dir.join("tsconfig.json").is_file()) {
@@ -1141,6 +1173,24 @@ mod tests {
            ("pnpm", &["run".to_owned(), "build".to_owned()][..])
        );

+        // .NET: the solution, else the project; a module build is the file's project. An ASP.NET
+        // project's package.json (its front end) doesn't make it a TypeScript build.
+        let net = tmp.path().join("net");
+        write(&net, "App.sln", "");
+        write(&net, "src/Api/Api.csproj", "<Project/>");
+        write(&net, "src/Api/package.json", "{}");
+        write(&net, "src/Api/Program.cs", "");
+        let p = plan(&net, &BuildModel::default(), BuildKind::Build, None, None).unwrap();
+        assert_eq!(p.system, BuildSystem::Dotnet);
+        assert_eq!(p.steps[0].args, ["build", "App.sln", "-nologo", "-clp:NoSummary"]);
+        assert_eq!(p.steps[0].env["MSBUILDTERMINALLOGGER"], "off");
+        let p = plan(&net, &BuildModel::default(), BuildKind::Rebuild, Some(&net.join("src/Api/Program.cs")), None)
+            .unwrap();
+        assert_eq!(p.steps[0].args, ["build", "Api.csproj", "-nologo", "-clp:NoSummary", "--no-incremental"]);
+        assert_eq!(p.steps[0].cwd, net.join("src/Api"));
+        let p = plan(&net, &BuildModel::default(), BuildKind::Artifacts, None, None).unwrap();
+        assert_eq!(p.steps[0].args[0], "publish");
+
        let cm = tmp.path().join("cm");
        write(&cm, "CMakeLists.txt", "project(app)");
        let args = |p: &BuildPlan| p.steps.iter().map(|s| s.args.join(" ")).collect::<Vec<_>>();
@@ -25,6 +25,8 @@ pub(crate) enum Format {
    Go,
    /// GCC / Clang (through `cmake --build`): `src/a.cpp:12:5: error: msg`.
    Gcc,
+    /// MSBuild (`dotnet build`): `C:\p\A.cs(12,5): error CS1002: msg [C:\p\App.csproj]`.
+    Msbuild,
 }

 /// What a printed column counts.
@@ -144,6 +146,13 @@ fn bracket_pos(s: &str) -> Option<(u32, Option<u32>, &str)> {
    Some((line, col, rest.trim_start()))
 }

+/// `/C:/p/A.java` → `C:/p/A.java`: Maven and file URIs put a `/` before the drive letter on Windows.
+/// Joined as is, it would become the drive-relative `C:p/A.java`.
+fn drive_path(p: &str) -> &str {
+    let b = p.as_bytes();
+    if b.len() > 2 && b[0] == b'/' && b[1].is_ascii_alphabetic() && b[2] == b':' { &p[1..] } else { p }
+}
+
 /// `file:///p/A.kt` → `/p/A.kt` (percent-decoded).
 fn from_file_uri(s: &str) -> String {
    let Some(rest) = s.strip_prefix("file://") else { return s.to_owned() };
@@ -162,9 +171,7 @@ fn from_file_uri(s: &str) -> String {
        out.push(bytes[i]);
        i += 1;
    }
-    let path = String::from_utf8_lossy(&out).into_owned();
-    // `file:///C:/x` on Windows.
-    if path.len() > 2 && path.as_bytes()[0] == b'/' && path.as_bytes()[2] == b':' { path[1..].to_owned() } else { path }
+    drive_path(&String::from_utf8_lossy(&out)).to_owned()
 }

 /// Kotlin: `file:///p/A.kt:12:5 msg` or `/p/A.kt: (12, 5): msg`, after the `e: ` / `w: ` prefix.
@@ -222,7 +229,7 @@ fn maven_line(line: &str) -> Option<RawMessage> {
        && looks_like_source_path(path)
        && let Some((ln, col, msg)) = bracket_pos(&format!("[{pos}"))
    {
-        return Some(RawMessage::new(severity, msg, ColUnit::Char).at(path, ln, col));
+        return Some(RawMessage::new(severity, msg, ColUnit::Char).at(drive_path(path), ln, col));
    }
    if let Some(m) = kotlin_line(rest) {
        return Some(m);
@@ -263,6 +270,43 @@ fn tsc_line(line: &str) -> Option<RawMessage> {
    Some(m)
 }

+/// MSBuild's canonical form: `path(12,5): error CS1002: msg [project]`, `path(12,5,12,9): …`,
+/// or `path : error NU1101: msg [project]` for a project-level message (no position).
+/// The path may contain spaces (`C:\Users\Jane Doe\…`); "error" / "warning" are never localized.
+fn msbuild_line(line: &str) -> Option<RawMessage> {
+    let line = line.trim();
+    // The project the message came from, appended by the console logger.
+    let line = match line.rfind(" [") {
+        Some(i) if line.ends_with(']') => &line[..i],
+        _ => line,
+    };
+    let (head, severity, rest) =
+        [(" error ", Severity::Error), (" warning ", Severity::Warning)].into_iter().find_map(|(word, severity)| {
+            let i = line.find(&format!(":{word}"))?;
+            Some((&line[..i], severity, &line[i + word.len() + 1..]))
+        })?;
+    let (code, msg) = rest.split_once(':')?;
+    let code = code.trim();
+    if code.is_empty() || code.contains(' ') {
+        return None;
+    }
+    let head = head.trim_end();
+    let (path, pos) = match head.strip_suffix(')').and_then(|h| h.rsplit_once('(')) {
+        Some((path, pos)) => (path, pos.split(',').map(num).collect::<Vec<_>>()),
+        None => (head, Vec::new()),
+    };
+    let at = |i: usize| pos.get(i).copied().flatten();
+    // `MSBUILD : error MSB1009` and the like name no file.
+    let file = path.rsplit(['/', '\\']).next().is_some_and(|n| n.contains('.'));
+    let mut m = RawMessage::new(severity, msg.trim(), ColUnit::Utf16);
+    if file {
+        m.path = Some(path.trim().to_owned());
+        (m.line, m.col, m.end_line, m.end_col) = (at(0), at(1), at(2), at(3));
+    }
+    m.code = Some(code.to_owned());
+    Some(m)
+}
+
 /// go: `./a.go:12:5: msg` (errors only; `go vet` style `a.go:12: msg` too).
 fn go_line(line: &str) -> Option<RawMessage> {
    let (path, ln, col, rest) = path_line_col(line)?;
@@ -399,6 +443,7 @@ impl OutputParser {
            Format::Tsc => tsc_line(&line),
            Format::Go => go_line(&line),
            Format::Gcc => gcc_line(&line),
+            Format::Msbuild => msbuild_line(&line),
            Format::Cargo => None,
        };
        if let Some(msg) = parsed {
@@ -456,6 +501,20 @@ mod tests {
        assert_eq!(out[1].unit, ColUnit::Char);
    }

+    #[test]
+    fn maven_windows_paths_drop_the_slash_before_the_drive() {
+        let out = parse(
+            Format::Maven,
+            "[ERROR] /C:/dev/p/src/main/java/a/A.java:[18,41] package a.b does not exist\n\
+             [ERROR] C:\\dev\\p\\B.java:[3,8] cannot find symbol\n\
+             [ERROR] file:///C:/dev/p/K.kt:4:9 Unresolved reference 'x'.\n",
+        );
+        assert_eq!(out.len(), 3, "{out:?}");
+        assert_eq!(pos(&out[0]), (Severity::Error, "C:/dev/p/src/main/java/a/A.java", 18, Some(41)));
+        assert_eq!(pos(&out[1]), (Severity::Error, "C:\\dev\\p\\B.java", 3, Some(8)));
+        assert_eq!(pos(&out[2]), (Severity::Error, "C:/dev/p/K.kt", 4, Some(9)));
+    }
+
    #[test]
    fn maven_detail_lines_with_level_prefix_and_kotlin() {
        let out = parse(
@@ -532,6 +591,27 @@ mod tests {
        assert!(plain.messages.is_empty() && plain.console.is_none());
    }

+    #[test]
+    fn msbuild_canonical_messages() {
+        let out = parse(
+            Format::Msbuild,
+            "  Determining projects to restore...\n\
+             C:\\Users\\Jane Doe\\App\\Program.cs(12,5): error CS1002: ; expected [C:\\Users\\Jane Doe\\App\\App.csproj]\n\
+             /p/App/Models/User.cs(3,8,3,12): warning CS0168: The variable 'e' is declared but never used [/p/App/App.csproj]\n\
+             /p/App/App.csproj : error NU1101: Unable to find package Foo. [/p/App/App.csproj]\n\
+             MSBUILD : error MSB1009: Project file does not exist.\n\
+             Build FAILED.\n",
+        );
+        assert_eq!(out.len(), 4, "{out:?}");
+        assert_eq!(pos(&out[0]), (Severity::Error, "C:\\Users\\Jane Doe\\App\\Program.cs", 12, Some(5)));
+        assert_eq!((out[0].code.as_deref(), out[0].text.as_str()), (Some("CS1002"), "; expected"));
+        assert_eq!(pos(&out[1]), (Severity::Warning, "/p/App/Models/User.cs", 3, Some(8)));
+        assert_eq!((out[1].end_line, out[1].end_col), (Some(3), Some(12)));
+        assert_eq!((out[2].path.as_deref(), out[2].line), (Some("/p/App/App.csproj"), None));
+        assert_eq!(out[2].text, "Unable to find package Foo.");
+        assert_eq!((out[3].path.as_deref(), out[3].code.as_deref()), (None, Some("MSB1009")));
+    }
+
    #[test]
    fn tsc_plain_and_pretty() {
        let out = parse(
@@ -118,6 +118,10 @@ pub enum IdeEvent {
    LanguageServer {
        server: ServerId,
        name: String,
+        /// What the user sees as the server when another program serves in its place.
+        #[serde(default)]
+        #[specta(optional)]
+        label: Option<String>,
        status: ServerStatus,
        message: Option<String>,
    },
@@ -291,6 +295,56 @@ pub enum DebugEvent {
    JvmBackend {
        state: JvmBackendState,
    },
+    /// A step in the life of one request of a debugged page.
+    JsNetwork {
+        event: JsNetworkEvent,
+    },
+    /// The adapter does not report the requests of this page: there will be no `JsNetwork`.
+    JsNetworkUnavailable,
+}
+
+/// Which step of a request a [`JsNetworkEvent`] reports.
+#[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub enum JsNetworkKind {
+    Request,
+    Response,
+    Finished,
+    Failed,
+}
+
+/// The script frame that made a request, where the browser ran it (0-based line and column).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JsInitiator {
+    pub function: String,
+    pub url: String,
+    pub line: u32,
+    pub column: u32,
+}
+
+/// What a debugged page's browser reports about a request, reduced to what the Network view
+/// shows. Events of one request share `request_id`; each kind fills its own fields.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JsNetworkEvent {
+    pub kind: JsNetworkKind,
+    pub request_id: String,
+    /// The browser's monotonic clock, comparable between the events of a page.
+    pub timestamp_ms: u64,
+    /// Request and response.
+    pub url: Option<String>,
+    pub method: Option<String>,
+    /// `Fetch`, `XHR`, `Script`, `Document`, …
+    pub resource_type: Option<String>,
+    pub status: Option<u16>,
+    pub mime_type: Option<String>,
+    /// The request's headers, or the response's.
+    pub headers: BTreeMap<String, String>,
+    /// Bytes received over the network, once finished.
+    pub encoded_length: Option<u64>,
+    pub error_text: Option<String>,
+    pub initiator: Option<JsInitiator>,
 }

 /// The backend that reads a debugged JVM's objects (instances, fields, referrers).
@@ -1,8 +1,10 @@
 //! JSON with comments (`devcontainer.json`, `deno.jsonc`, `tsconfig.json`): turned
 //! into plain JSON for `serde_json`.

-/// Strips `//` and `/* */` comments and trailing commas so JSONC parses as JSON.
+/// Strips `//` and `/* */` comments, trailing commas and a leading byte order mark (Visual
+/// Studio writes one into `launchSettings.json`) so JSONC parses as JSON.
 pub fn strip(src: &str) -> String {
+    let src = src.strip_prefix('\u{feff}').unwrap_or(src);
    let mut out = String::with_capacity(src.len());
    let mut chars = src.chars().peekable();
    let mut in_str = false;
@@ -87,4 +89,10 @@ mod tests {
        assert_eq!(v["url"], "https://x.dev//y /* no */");
        assert_eq!(v["q"], "say \"hi\",");
    }
+
+    #[test]
+    fn drops_a_byte_order_mark() {
+        let v: serde_json::Value = serde_json::from_str(&strip("\u{feff}{ \"a\": 1 }")).unwrap();
+        assert_eq!(v["a"], 1);
+    }
 }
@@ -291,7 +291,7 @@ pub enum NewTaskApprovals {
 #[derive(Clone, Debug, 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.
+    /// Serve the tools on [`Self::address`] 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.
@@ -300,6 +300,9 @@ pub struct McpServerSettings {
    pub agent_tab_limit: u32,
    /// Archived agent tabs kept; older ones are closed.
    pub agent_archive_limit: u32,
+    /// The IP address to listen on: `127.0.0.1` (this computer only, the default), another
+    /// address of this computer, or `0.0.0.0` / `::` for every address.
+    pub address: String,
    /// Listen on [`Self::port`] in every run, rather than a free port each time, so HTTP clients and
    /// port forwards keep working after a restart.
    pub fixed_port: bool,
@@ -312,6 +315,8 @@ pub struct McpServerSettings {

 /// The default of [`McpServerSettings::port`].
 pub const DEFAULT_MCP_PORT: u16 = 26371;
+/// The default of [`McpServerSettings::address`]: this computer only.
+pub const DEFAULT_MCP_ADDRESS: &str = "127.0.0.1";

 impl Default for McpServerSettings {
    fn default() -> Self {
@@ -320,6 +325,7 @@ impl Default for McpServerSettings {
            run_without_confirmation: false,
            agent_tab_limit: 1,
            agent_archive_limit: 999,
+            address: DEFAULT_MCP_ADDRESS.to_owned(),
            fixed_port: true,
            port: DEFAULT_MCP_PORT,
            fixed_token: false,
@@ -1086,7 +1092,8 @@ impl Default for ExternalFormatterSettings {
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct PythonSettings {
-    /// Project interpreter executable; empty = auto-detect (project venv, else `python3`).
+    /// Project interpreter executable; empty = auto-detect (project venv, else `python3`);
+    /// `target:<run-target-id>` = the Python of a Docker or Compose run target.
    pub interpreter: String,
    /// Activate the interpreter's virtualenv in new terminal sessions.
    pub activate_virtualenv: bool,
@@ -1115,6 +1122,17 @@ impl Default for PythonSettings {
    }
 }

+impl PythonSettings {
+    /// What `interpreter` starts with when the project interpreter is a run target's.
+    pub const TARGET_PREFIX: &str = "target:";
+
+    /// The run target whose Python is the project interpreter (`target:<id>`), if one is.
+    pub fn run_target(&self) -> Option<&str> {
+        let id = self.interpreter.trim().strip_prefix(Self::TARGET_PREFIX)?.trim();
+        (!id.is_empty()).then_some(id)
+    }
+}
+
 #[derive(Clone, Debug, Default, PartialEq, Serialize, Deserialize, Type)]
 #[serde(default, rename_all = "camelCase")]
 pub struct PhpSettings {
@@ -1153,6 +1171,9 @@ pub struct NodeSettings {
    pub run_target: String,
    /// `npm` | `pnpm` | `yarn`; empty = detect from the lock file / `packageManager`.
    pub package_manager: String,
+    /// Runtime for running JavaScript / TypeScript files: `node` | `bun` | `deno`; empty = from the
+    /// project (`deno.json` → Deno, `bun.lock` → Bun, else Node.js).
+    pub runtime: String,
 }

 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize, Type)]
@@ -1349,11 +1370,15 @@ pub struct TypeScriptSettings {
    /// `bundled` (the server's own TypeScript), `workspace` (`node_modules/typescript`),
    /// or a path to a TypeScript `lib` directory.
    pub version: String,
+    /// tsserver heap limit in MB. `0` = automatic: 8192 when vtsls hosts the Vue
+    /// plugin (hybrid mode; a Vue project's program alone needs ~3 GiB, and the
+    /// vtsls default 3072 dies in a GC death spiral), else unset (vtsls default).
+    pub tsserver_max_memory: u32,
 }

 impl Default for TypeScriptSettings {
    fn default() -> Self {
-        Self { version: "bundled".into() }
+        Self { version: "bundled".into(), tsserver_max_memory: 0 }
    }
 }

@@ -1529,6 +1554,16 @@ impl Settings {
 mod tests {
    use super::*;

+    #[test]
+    fn python_interpreter_may_name_a_run_target() {
+        let python = |interpreter: &str| PythonSettings { interpreter: interpreter.into(), ..Default::default() };
+        assert_eq!(python("target:web").run_target(), Some("web"));
+        assert_eq!(python(" target: web ").run_target(), Some("web"));
+        for local in ["", "target:", "/usr/bin/python3", ".venv/bin/python", "targets/python"] {
+            assert_eq!(python(local).run_target(), None, "{local}");
+        }
+    }
+
    #[test]
    fn removed_one_themes_read_as_islands_themes() {
        let settings: Settings = serde_json::from_str(
@@ -260,18 +260,24 @@ pub struct DebuggerSettings {
    pub show_on_breakpoint: bool,
    pub focus_app_on_breakpoint: bool,
    pub hide_on_termination: bool,
+    /// A breakpoint or exception hit brings the Debug tool window's Threads & Variables tab to the front.
+    pub variables_on_breakpoint: bool,
    pub breakpoints_any_file: bool,
    /// While suspended, hovering the start of a line shows a Run to Cursor button.
    pub run_to_cursor_inlay: bool,
    pub inline_values: bool,
    /// Data Views: list variables by name instead of the adapter's order.
    pub sort_values: bool,
+    /// Data Views: evaluate watches while the program runs, where the debugger can (JavaScript).
+    pub live_watches: bool,
    pub value_tooltip: bool,
    /// While suspended, selecting an expression shows its value.
    pub value_tooltip_on_selection: bool,
    pub value_tooltip_delay: u32,
    /// Stepping: do not step into library code (debugpy `justMyCode`, js-debug `skipFiles`).
    pub skip_library_code: bool,
+    /// JavaScript: debugging a dev server (`vite`, `next dev`) also opens its page in a browser session.
+    pub debug_server_page: bool,
    pub python: PythonDebuggerSettings,
 }

@@ -281,14 +287,17 @@ impl Default for DebuggerSettings {
            show_on_breakpoint: true,
            focus_app_on_breakpoint: false,
            hide_on_termination: false,
+            variables_on_breakpoint: true,
            breakpoints_any_file: false,
            run_to_cursor_inlay: true,
            inline_values: true,
            sort_values: false,
+            live_watches: false,
            value_tooltip: true,
            value_tooltip_on_selection: true,
            value_tooltip_delay: 700,
            skip_library_code: true,
+            debug_server_page: false,
            python: PythonDebuggerSettings::default(),
        }
    }
@@ -7,6 +7,8 @@ license.workspace = true

 [dependencies]
 futures.workspace = true
+tokio-tungstenite.workspace = true
+base64.workspace = true
 tempfile.workspace = true
 ide-core.workspace = true
 ide-language.workspace = true
@@ -9,6 +9,7 @@
 use ide_core::process::executable_names;
 use ide_core::{IdeError, IdeResult};
 use ide_language::{DebuggerConfig, LanguageRegistry, ProgramPin};
+use serde_json::Value;
 use std::future::Future;
 use std::path::{Path, PathBuf};
 use std::pin::Pin;
@@ -212,6 +213,50 @@ pub fn tools_root() -> Option<PathBuf> {
    TOOLS_ROOT.read().clone()
 }

+/// The browser js-debug launches for `ty`, or `None` when the launch starts no browser.
+fn launched_browser(ty: &str) -> Option<&'static str> {
+    match ty {
+        "pwa-chrome" | "chrome" => Some("chrome"),
+        "pwa-msedge" | "msedge" => Some("msedge"),
+        _ => None,
+    }
+}
+
+/// Gives a browser launch that names no `userDataDir` a profile of `project`'s own in the
+/// IDE's local data (`cache/browser-profiles`), so sign-ins and site data are still there in
+/// the next session. js-debug's own default is one temporary profile for every project.
+pub(crate) fn set_browser_profile(arguments: &mut Value, project: &Path) {
+    if let Some(local_data) = tools_root().and_then(|tools| tools.parent().map(Path::to_owned)) {
+        set_browser_profile_in(arguments, project, &local_data);
+    }
+}
+
+fn set_browser_profile_in(arguments: &mut Value, project: &Path, local_data: &Path) {
+    let Some(obj) = arguments.as_object_mut() else { return };
+    let browser = obj.get("type").and_then(Value::as_str).and_then(launched_browser);
+    let launch = obj.get("request").and_then(Value::as_str) == Some("launch");
+    let (Some(browser), true, false) = (browser, launch, obj.contains_key("userDataDir")) else { return };
+    let dir = local_data.join("cache").join("browser-profiles").join(profile_name(project)).join(browser);
+    obj.insert("userDataDir".into(), dir.to_string_lossy().into_owned().into());
+}
+
+/// `<folder name>-<hash of the path>`: readable, and distinct for projects whose folders share a name.
+fn profile_name(project: &Path) -> String {
+    // FNV-1a: the name has to stay the same across toolchains, which `DefaultHasher` doesn't promise.
+    let hash = project
+        .to_string_lossy()
+        .bytes()
+        .fold(0xcbf2_9ce4_8422_2325_u64, |h, b| (h ^ u64::from(b)).wrapping_mul(0x0000_0100_0000_01b3));
+    let name: String = project
+        .file_name()
+        .map(|n| n.to_string_lossy().into_owned())
+        .unwrap_or_default()
+        .chars()
+        .map(|c| if c.is_ascii_alphanumeric() || c == '-' || c == '_' || c == '.' { c } else { '_' })
+        .collect();
+    format!("{name}-{hash:016x}")
+}
+
 /// Executable directories of managed installs, read at lookup time so tools installed
 /// after startup are found without a restart: `<tool>/bin`, `<tool>/venv/bin`, npm's `.bin`.
 fn managed_dirs(root: &Path) -> Vec<PathBuf> {
@@ -1040,6 +1085,33 @@ mod tests {
        assert!(err.message.contains("runs inside the Java language server"), "{}", err.message);
    }

+    #[test]
+    fn a_browser_launch_gets_a_profile_of_its_project() {
+        let local = Path::new("/data/local");
+        let profile = |args: serde_json::Value, project: &str| {
+            let mut args = args;
+            set_browser_profile_in(&mut args, Path::new(project), local);
+            args.get("userDataDir").cloned()
+        };
+        let chrome = serde_json::json!({ "type": "pwa-chrome", "request": "launch" });
+        let dir = profile(chrome.clone(), "/work/shop").unwrap();
+        let dir = Path::new(dir.as_str().unwrap());
+        assert!(dir.starts_with("/data/local/cache/browser-profiles"), "{dir:?}");
+        assert!(dir.ends_with("chrome"), "{dir:?}");
+        let name = dir.parent().unwrap().file_name().unwrap().to_string_lossy().into_owned();
+        assert!(name.starts_with("shop-") && name.len() == "shop-".len() + 16, "{name}");
+        // The same project again: the same profile. Another folder of that name, or Edge: another one.
+        assert_eq!(profile(chrome.clone(), "/work/shop").unwrap(), dir.to_string_lossy().as_ref());
+        assert_ne!(profile(chrome.clone(), "/other/shop").unwrap(), dir.to_string_lossy().as_ref());
+        let edge = profile(serde_json::json!({ "type": "pwa-msedge", "request": "launch" }), "/work/shop").unwrap();
+        assert!(Path::new(edge.as_str().unwrap()).ends_with("msedge"), "{edge}");
+        // A chosen profile (or the default one, `false`) is kept; Node and attach requests get none.
+        let own = serde_json::json!({ "type": "pwa-chrome", "request": "launch", "userDataDir": false });
+        assert_eq!(profile(own, "/work/shop"), Some(false.into()));
+        assert_eq!(profile(serde_json::json!({ "type": "pwa-node", "request": "launch" }), "/work/shop"), None);
+        assert_eq!(profile(serde_json::json!({ "type": "pwa-chrome", "request": "attach" }), "/work/shop"), None);
+    }
+
    #[test]
    fn port_conflicts_are_recognised_for_retry() {
        let in_use = IdeError::unavailable(
@@ -0,0 +1,528 @@
+//! Replacing the responses a debugged page receives. js-debug hands out a WebSocket that
+//! speaks the browser's own protocol (`requestCDPProxy`); over it the browser is told to hold
+//! the requests whose URL matches a rule (`Fetch.enable`) and each held request is answered
+//! here, with the rule's response or by letting it through.
+//!
+//! A held request stays held until it is answered, so interception is always switched off
+//! (`Fetch.disable`) before the connection is given up: a page whose requests nobody answers hangs.
+
+use crate::{DebugManager, DebugSessionId, REQUEST_TIMEOUT, js_debug};
+use base64::Engine;
+use futures::{SinkExt, StreamExt};
+use ide_core::{IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use serde_json::{Value, json};
+use specta::Type;
+use std::collections::HashMap;
+use tokio::sync::{oneshot, watch};
+use tokio_tungstenite::tungstenite::{Message, http::StatusCode};
+
+/// A response given in place of the server's to every request whose URL contains `url_contains`.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JsResponseRule {
+    pub url_contains: String,
+    pub status: u16,
+    pub content_type: String,
+    pub body: String,
+}
+
+/// The browser's URL pattern (`*` any text, `?` one character, `\` escapes) for "contains `part`".
+pub(crate) fn url_pattern(part: &str) -> String {
+    let mut pattern = String::with_capacity(part.len() + 2);
+    pattern.push('*');
+    for c in part.chars() {
+        if matches!(c, '*' | '?' | '\\') {
+            pattern.push('\\');
+        }
+        pattern.push(c);
+    }
+    pattern.push('*');
+    pattern
+}
+
+pub(crate) fn rule_for<'a>(rules: &'a [JsResponseRule], url: &str) -> Option<&'a JsResponseRule> {
+    rules.iter().find(|rule| url.contains(&rule.url_contains))
+}
+
+/// What to tell the browser about a request it holds: the first matching rule's response, or
+/// to send the request on. Every held request gets one of the two.
+pub(crate) fn answer(held: &Value, rules: &[JsResponseRule]) -> (&'static str, Value) {
+    let request_id = held.get("requestId").and_then(Value::as_str).unwrap_or_default();
+    let url = held.pointer("/request/url").and_then(Value::as_str).unwrap_or_default();
+    let Some(rule) = rule_for(rules, url) else {
+        return ("Fetch.continueRequest", json!({ "requestId": request_id }));
+    };
+    let header = |name: &str, value: &str| json!({ "name": name, "value": value });
+    // A page on another origin only reads a response that names its origin. The server would
+    // say so; the response given in its place has to.
+    let mut cross_origin = Vec::new();
+    if let Some(origin) = request_header(held, "Origin") {
+        cross_origin.push(header("Access-Control-Allow-Origin", origin));
+        cross_origin.push(header("Access-Control-Allow-Credentials", "true"));
+    }
+    let method = held.pointer("/request/method").and_then(Value::as_str).unwrap_or_default();
+    // The browser's question before such a request: allowed here, the server may not exist.
+    if method == "OPTIONS"
+        && let Some(asked) = request_header(held, "Access-Control-Request-Method")
+    {
+        cross_origin.push(header("Access-Control-Allow-Methods", asked));
+        if let Some(asked) = request_header(held, "Access-Control-Request-Headers") {
+            cross_origin.push(header("Access-Control-Allow-Headers", asked));
+        }
+        let allowed = json!({
+            "requestId": request_id,
+            "responseCode": 204,
+            "responsePhrase": phrase(204),
+            "responseHeaders": cross_origin,
+        });
+        return ("Fetch.fulfillRequest", allowed);
+    }
+    let mut headers = vec![header("Content-Type", &rule.content_type)];
+    headers.extend(cross_origin);
+    let replaced = json!({
+        "requestId": request_id,
+        "responseCode": rule.status,
+        "responsePhrase": phrase(rule.status),
+        "responseHeaders": headers,
+        "body": base64::engine::general_purpose::STANDARD.encode(rule.body.as_bytes()),
+    });
+    ("Fetch.fulfillRequest", replaced)
+}
+
+/// A header of the held request; the browser reports names as the page wrote them.
+fn request_header<'a>(held: &'a Value, name: &str) -> Option<&'a str> {
+    held.pointer("/request/headers")?.as_object()?.iter().find(|(key, _)| key.eq_ignore_ascii_case(name))?.1.as_str()
+}
+
+/// The browser refuses a response without a phrase when it has none of its own for the status.
+fn phrase(status: u16) -> &'static str {
+    StatusCode::from_u16(status).ok().and_then(|status| status.canonical_reason()).unwrap_or("Unknown")
+}
+
+fn interception(rules: &[JsResponseRule]) -> Value {
+    let patterns: Vec<Value> = rules
+        .iter()
+        .map(|rule| json!({ "urlPattern": url_pattern(&rule.url_contains), "requestStage": "Request" }))
+        .collect();
+    json!({ "patterns": patterns })
+}
+
+/// Applies `rules` to the page behind js-debug's CDP proxy at `ws_url` until their sender is
+/// dropped (the session is gone) or the proxy closes the connection. The browser holds
+/// requests only while there are rules. `ready` hears whether the proxy reports held
+/// requests at all; nothing is held before it has agreed to.
+pub(crate) async fn serve(
+    ws_url: String,
+    mut rules: watch::Receiver<Vec<JsResponseRule>>,
+    ready: oneshot::Sender<Result<(), String>>,
+) {
+    let socket = match tokio_tungstenite::connect_async(ws_url.as_str()).await {
+        Ok((socket, _)) => socket,
+        Err(e) => {
+            let _ = ready.send(Err(e.to_string()));
+            return;
+        }
+    };
+    let (mut write, mut read) = socket.split();
+    let mut last_id = 0u64;
+    let mut call = |method: &str, params: Value| {
+        last_id += 1;
+        (last_id, Message::text(json!({ "id": last_id, "method": method, "params": params }).to_string()))
+    };
+
+    let (subscription, subscribe) = call("JsDebug.subscribe", json!({ "events": ["Fetch.requestPaused"] }));
+    let subscribed = tokio::time::timeout(REQUEST_TIMEOUT, async {
+        write.send(subscribe).await.map_err(|e| e.to_string())?;
+        loop {
+            let reply = read.next().await.ok_or("the connection closed")?.map_err(|e| e.to_string())?;
+            let Some(reply) = reply.to_text().ok().and_then(|text| serde_json::from_str::<Value>(text).ok()) else {
+                continue;
+            };
+            if reply.get("id").and_then(Value::as_u64) != Some(subscription) {
+                continue;
+            }
+            break match reply.get("error") {
+                Some(error) => Err(error.get("message").and_then(Value::as_str).unwrap_or("refused").to_owned()),
+                None => Ok(()),
+            };
+        }
+    })
+    .await
+    .unwrap_or_else(|_| Err("no answer".to_owned()));
+    if let Err(why) = subscribed {
+        let _ = ready.send(Err(why));
+        let _ = write.close().await;
+        return;
+    }
+    let _ = ready.send(Ok(()));
+
+    let mut current = rules.borrow_and_update().clone();
+    let mut holding = !current.is_empty();
+    if holding && write.send(call("Fetch.enable", interception(&current)).1).await.is_err() {
+        return;
+    }
+    // The request each sent replacement is for, by command id, until the browser has taken it.
+    let mut replacing: HashMap<u64, String> = HashMap::new();
+    loop {
+        tokio::select! {
+            changed = rules.changed() => {
+                if changed.is_err() {
+                    break;
+                }
+                current = rules.borrow_and_update().clone();
+                let (_, command) = match (current.is_empty(), holding) {
+                    (true, false) => continue,
+                    (true, true) => call("Fetch.disable", json!({})),
+                    (false, _) => call("Fetch.enable", interception(&current)),
+                };
+                holding = !current.is_empty();
+                if write.send(command).await.is_err() {
+                    return;
+                }
+            }
+            message = read.next() => {
+                // The proxy closed (the page or the session ended): nothing is held any more.
+                let Some(Ok(message)) = message else { return };
+                let Ok(text) = message.to_text() else { continue };
+                let Ok(message) = serde_json::from_str::<Value>(text) else { continue };
+                if let Some(id) = message.get("id").and_then(Value::as_u64) {
+                    // The browser did not take the replacement: let the request through, or
+                    // it stays held and the page waits for it.
+                    if let Some(request_id) = replacing.remove(&id)
+                        && message.get("error").is_some()
+                    {
+                        let (_, go_on) = call("Fetch.continueRequest", json!({ "requestId": request_id }));
+                        if write.send(go_on).await.is_err() {
+                            return;
+                        }
+                    }
+                    continue;
+                }
+                if message.get("method").and_then(Value::as_str) != Some("Fetch.requestPaused") {
+                    continue;
+                }
+                let Some(held) = message.get("params") else { continue };
+                let Some(request_id) = held.get("requestId").and_then(Value::as_str) else { continue };
+                let (method, params) = answer(held, &current);
+                let (id, command) = call(method, params);
+                if method == "Fetch.fulfillRequest" {
+                    replacing.insert(id, request_id.to_owned());
+                }
+                if write.send(command).await.is_err() {
+                    return;
+                }
+            }
+        }
+    }
+    if holding {
+        let _ = write.send(call("Fetch.disable", json!({})).1).await;
+    }
+    let _ = write.close().await;
+}
+
+impl DebugManager {
+    /// Makes `rules` the page's response rules; none switches the replacing off. The first
+    /// rules of a session open the connection to js-debug's CDP proxy, later ones go over it.
+    /// An error means the rules are not applied.
+    pub async fn js_set_response_overrides(&self, s: DebugSessionId, rules: Vec<JsResponseRule>) -> IdeResult<()> {
+        let session = self.session(s)?;
+        if !js_debug::is_page(&session) {
+            return Err(IdeError::unavailable("this debug session is not a page in a browser"));
+        }
+        // Held to the end: two callers at once would each open a connection.
+        let mut applied = session.js_overrides.lock().await;
+        if applied.as_ref().is_some_and(|sender| sender.send(rules.clone()).is_ok()) {
+            return Ok(());
+        }
+        // No connection yet, or the proxy closed it.
+        applied.take();
+        if rules.is_empty() {
+            return Ok(());
+        }
+        let refused =
+            |why: String| IdeError::unavailable(format!("the JavaScript debugger has no browser connection: {why}"));
+        if !js_debug::launched(&session).await {
+            return Err(refused("the page's debug session did not finish starting".into()));
+        }
+        let proxy = session
+            .conn
+            .request_timeout("requestCDPProxy", json!({}), REQUEST_TIMEOUT)
+            .await
+            .map_err(|e| refused(e.to_string()))?;
+        let (Some(host), Some(port)) =
+            (proxy.get("host").and_then(Value::as_str), proxy.get("port").and_then(Value::as_u64))
+        else {
+            return Err(refused("no address".into()));
+        };
+        let path = proxy.get("path").and_then(Value::as_str).unwrap_or_default();
+        let (sender, receiver) = watch::channel(rules);
+        let (ready, is_ready) = oneshot::channel();
+        tokio::spawn(serve(format!("ws://{host}:{port}{path}"), receiver, ready));
+        match is_ready.await {
+            Ok(Ok(())) => {
+                *applied = Some(sender);
+                Ok(())
+            }
+            Ok(Err(why)) => Err(refused(why)),
+            Err(_) => Err(refused("no answer".into())),
+        }
+    }
+}
+
+#[cfg(test)]
+pub(crate) mod tests {
+    use super::*;
+    use futures::{SinkExt, StreamExt};
+    use serde_json::json;
+    use tokio::sync::mpsc;
+    use tokio_tungstenite::tungstenite::Message;
+
+    pub(crate) fn rule(url_contains: &str, status: u16, body: &str) -> JsResponseRule {
+        JsResponseRule {
+            url_contains: url_contains.into(),
+            status,
+            content_type: "application/json".into(),
+            body: body.into(),
+        }
+    }
+
+    #[test]
+    fn a_part_of_a_url_becomes_a_pattern_that_matches_it_anywhere() {
+        assert_eq!(url_pattern("api/items"), "*api/items*");
+        // The pattern's own wildcards and escape character are taken literally.
+        assert_eq!(url_pattern(r"a*b?c\d"), r"*a\*b\?c\\d*");
+    }
+
+    #[test]
+    fn the_first_rule_whose_text_is_in_the_url_answers() {
+        let rules = [rule("api/items", 201, "{\"a\":\"é\"}"), rule("api", 500, "later")];
+        assert_eq!(rule_for(&rules, "http://h/api/items?x=1").map(|r| r.status), Some(201));
+        assert_eq!(rule_for(&rules, "http://h/api/users").map(|r| r.status), Some(500));
+        assert!(rule_for(&rules, "http://h/logo.png").is_none());
+
+        let (command, params) = answer(&held("7", "http://h/api/items")["params"], &rules);
+        assert_eq!(command, "Fetch.fulfillRequest");
+        assert_eq!(
+            params,
+            json!({
+                "requestId": "7",
+                "responseCode": 201,
+                "responsePhrase": "Created",
+                "responseHeaders": [{ "name": "Content-Type", "value": "application/json" }],
+                // base64 of the UTF-8 text `{"a":"é"}`
+                "body": "eyJhIjoiw6kifQ==",
+            })
+        );
+        // A request the browser held that no rule is for goes on to the network.
+        assert_eq!(
+            answer(&held("8", "http://h/logo.png")["params"], &rules),
+            ("Fetch.continueRequest", json!({ "requestId": "8" }))
+        );
+    }
+
+    #[test]
+    fn a_status_the_browser_has_no_phrase_for_is_given_one() {
+        // The browser refuses a response whose status it cannot name.
+        let (_, params) = answer(&held("1", "http://h/api")["params"], &[rule("api", 419, "")]);
+        assert_eq!((&params["responseCode"], &params["responsePhrase"]), (&json!(419), &json!("Unknown")));
+    }
+
+    fn header<'a>(params: &'a Value, name: &str) -> Option<&'a str> {
+        params["responseHeaders"].as_array()?.iter().find(|h| h["name"] == name)?["value"].as_str()
+    }
+
+    #[test]
+    fn a_replaced_response_passes_the_pages_cross_origin_check() {
+        let rules = [rule("api/items", 200, "[]")];
+        let from_page = |method: &str, headers: Value| json!({ "requestId": "3", "request": { "url": "http://localhost:8080/api/items", "method": method, "headers": headers } });
+        // A page on another origin: the response names that origin, as the real server would.
+        let (_, params) = answer(&from_page("GET", json!({ "origin": "http://localhost:5173" })), &rules);
+        assert_eq!(header(&params, "Access-Control-Allow-Origin"), Some("http://localhost:5173"));
+        assert_eq!(header(&params, "Access-Control-Allow-Credentials"), Some("true"));
+        assert_eq!(params["body"], "W10=");
+
+        // The browser's question before such a request is answered too: the server may not exist.
+        let preflight = from_page(
+            "OPTIONS",
+            json!({
+                "Origin": "http://localhost:5173",
+                "Access-Control-Request-Method": "PUT",
+                "Access-Control-Request-Headers": "content-type,x-token",
+            }),
+        );
+        let (command, params) = answer(&preflight, &rules);
+        assert_eq!((command, &params["responseCode"]), ("Fetch.fulfillRequest", &json!(204)));
+        assert_eq!(header(&params, "Access-Control-Allow-Origin"), Some("http://localhost:5173"));
+        assert_eq!(header(&params, "Access-Control-Allow-Methods"), Some("PUT"));
+        assert_eq!(header(&params, "Access-Control-Allow-Headers"), Some("content-type,x-token"));
+        assert_eq!(params.get("body"), None);
+
+        // Same origin: nothing but the rule's own header.
+        let (_, params) = answer(&from_page("GET", json!({})), &rules);
+        assert_eq!(params["responseHeaders"], json!([{ "name": "Content-Type", "value": "application/json" }]));
+    }
+
+    /// A stand-in for js-debug's CDP proxy: what it receives, and a way to send it events.
+    pub(crate) async fn proxy() -> (String, mpsc::UnboundedReceiver<Value>, mpsc::UnboundedSender<Value>) {
+        proxy_refusing(|_| false).await
+    }
+
+    /// A proxy that answers the commands `refused` picks with an error, like the real one does
+    /// for what it or the browser does not accept.
+    pub(crate) async fn proxy_refusing(
+        refused: fn(&Value) -> bool,
+    ) -> (String, mpsc::UnboundedReceiver<Value>, mpsc::UnboundedSender<Value>) {
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let url = format!("ws://127.0.0.1:{}/session", listener.local_addr().unwrap().port());
+        let (received_tx, received) = mpsc::unbounded_channel();
+        let (events, mut events_rx) = mpsc::unbounded_channel::<Value>();
+        tokio::spawn(async move {
+            let (stream, _) = listener.accept().await.unwrap();
+            let (mut write, mut read) = tokio_tungstenite::accept_async(stream).await.unwrap().split();
+            loop {
+                tokio::select! {
+                    message = read.next() => {
+                        let Some(Ok(message)) = message else { break };
+                        let Ok(text) = message.to_text() else { continue };
+                        let Ok(request) = serde_json::from_str::<Value>(text) else { continue };
+                        let reply = if refused(&request) {
+                            json!({ "id": request["id"], "error": { "code": -32602, "message": "refused" } })
+                        } else {
+                            json!({ "id": request["id"], "result": {} })
+                        };
+                        let _ = write.send(Message::text(reply.to_string())).await;
+                        let _ = received_tx.send(request);
+                    }
+                    Some(event) = events_rx.recv() => {
+                        let _ = write.send(Message::text(event.to_string())).await;
+                    }
+                }
+            }
+        });
+        (url, received, events)
+    }
+
+    pub(crate) async fn next(received: &mut mpsc::UnboundedReceiver<Value>) -> (String, Value) {
+        let request = tokio::time::timeout(std::time::Duration::from_secs(5), received.recv())
+            .await
+            .expect("the proxy got a request in time")
+            .expect("the connection is open");
+        (request["method"].as_str().unwrap().to_owned(), request["params"].clone())
+    }
+
+    /// The browser's event for a request it holds.
+    fn held(request_id: &str, url: &str) -> Value {
+        json!({ "method": "Fetch.requestPaused", "params": { "requestId": request_id, "request": { "url": url } } })
+    }
+
+    type Serving = (tokio::task::JoinHandle<()>, oneshot::Receiver<Result<(), String>>);
+
+    fn serving(url: String, rules: watch::Receiver<Vec<JsResponseRule>>) -> Serving {
+        let (ready, is_ready) = oneshot::channel();
+        (tokio::spawn(serve(url, rules, ready)), is_ready)
+    }
+
+    async fn ended(task: tokio::task::JoinHandle<()>) {
+        tokio::time::timeout(std::time::Duration::from_secs(5), task).await.unwrap().unwrap();
+    }
+
+    #[tokio::test]
+    async fn held_requests_are_answered_and_interception_ends_before_the_connection() {
+        let (url, mut received, events) = proxy().await;
+        let (rules, watched) = tokio::sync::watch::channel(vec![rule("api/items", 200, "[]")]);
+        let (serving, ready) = serving(url, watched);
+        assert_eq!(ready.await.unwrap(), Ok(()));
+
+        assert_eq!(
+            next(&mut received).await,
+            ("JsDebug.subscribe".into(), json!({ "events": ["Fetch.requestPaused"] }))
+        );
+        assert_eq!(
+            next(&mut received).await,
+            (
+                "Fetch.enable".into(),
+                json!({ "patterns": [{ "urlPattern": "*api/items*", "requestStage": "Request" }] })
+            )
+        );
+
+        events.send(held("1", "http://h/api/items")).unwrap();
+        let (command, params) = next(&mut received).await;
+        assert_eq!(
+            (command.as_str(), &params["requestId"], &params["responseCode"]),
+            ("Fetch.fulfillRequest", &json!("1"), &json!(200))
+        );
+        events.send(held("2", "http://h/other")).unwrap();
+        assert_eq!(next(&mut received).await, ("Fetch.continueRequest".into(), json!({ "requestId": "2" })));
+
+        // New rules replace the browser's patterns.
+        rules.send(vec![rule("api/users", 404, "{}")]).unwrap();
+        assert_eq!(
+            next(&mut received).await,
+            (
+                "Fetch.enable".into(),
+                json!({ "patterns": [{ "urlPattern": "*api/users*", "requestStage": "Request" }] })
+            )
+        );
+
+        // No rules left: the browser stops holding requests. The connection stays for the
+        // rules that come next, and goes with the session.
+        rules.send(Vec::new()).unwrap();
+        assert_eq!(next(&mut received).await.0, "Fetch.disable");
+        rules.send(vec![rule("api/items", 200, "[]")]).unwrap();
+        assert_eq!(next(&mut received).await.0, "Fetch.enable");
+        rules.send(Vec::new()).unwrap();
+        assert_eq!(next(&mut received).await.0, "Fetch.disable");
+        drop(rules);
+        ended(serving).await;
+        // Already off: not switched off a second time.
+        assert!(received.try_recv().is_err());
+    }
+
+    #[tokio::test]
+    async fn a_session_that_goes_away_switches_interception_off() {
+        let (url, mut received, _events) = proxy().await;
+        let (rules, watched) = tokio::sync::watch::channel(vec![rule("api", 200, "[]")]);
+        let (serving, _ready) = serving(url, watched);
+        assert_eq!(next(&mut received).await.0, "JsDebug.subscribe");
+        assert_eq!(next(&mut received).await.0, "Fetch.enable");
+        drop(rules);
+        assert_eq!(next(&mut received).await.0, "Fetch.disable");
+        ended(serving).await;
+    }
+
+    #[tokio::test]
+    async fn a_response_the_browser_refuses_lets_the_request_through() {
+        let (url, mut received, events) = proxy_refusing(|request| request["method"] == "Fetch.fulfillRequest").await;
+        let (_rules, watched) = tokio::sync::watch::channel(vec![rule("api", 200, "[]")]);
+        let (_serving, _ready) = serving(url, watched);
+        assert_eq!(next(&mut received).await.0, "JsDebug.subscribe");
+        assert_eq!(next(&mut received).await.0, "Fetch.enable");
+        events.send(held("9", "http://h/api")).unwrap();
+        assert_eq!(next(&mut received).await.0, "Fetch.fulfillRequest");
+        // Unanswered, the request would hang the page.
+        assert_eq!(next(&mut received).await, ("Fetch.continueRequest".into(), json!({ "requestId": "9" })));
+    }
+
+    #[tokio::test]
+    async fn a_proxy_that_does_not_report_held_requests_is_not_asked_to_hold_any() {
+        let (url, mut received, _events) = proxy_refusing(|request| request["method"] == "JsDebug.subscribe").await;
+        let (_rules, watched) = tokio::sync::watch::channel(vec![rule("api", 200, "[]")]);
+        let (serving, ready) = serving(url, watched);
+        assert_eq!(next(&mut received).await.0, "JsDebug.subscribe");
+        assert_eq!(ready.await.unwrap(), Err("refused".to_owned()));
+        ended(serving).await;
+        assert!(received.try_recv().is_err());
+    }
+
+    #[tokio::test]
+    async fn no_connection_to_the_proxy_is_reported() {
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let url = format!("ws://127.0.0.1:{}/session", listener.local_addr().unwrap().port());
+        drop(listener);
+        let (_rules, watched) = tokio::sync::watch::channel(vec![rule("api", 200, "[]")]);
+        let (serving, ready) = serving(url, watched);
+        assert!(ready.await.unwrap().is_err());
+        ended(serving).await;
+    }
+}
@@ -0,0 +1,323 @@
+//! Requests of vscode-js-debug's own, beyond the Debug Adapter Protocol: what a page in a
+//! browser offers a debugger besides stepping (breakpoints on DOM events and requests).
+//! Each is a typed method; a js-debug build that lacks one answers with an error, which is
+//! reported as the feature being unavailable.
+
+use crate::session::Session;
+use crate::{DebugManager, DebugSessionId, REQUEST_TIMEOUT};
+use ide_core::event::{JsInitiator, JsNetworkEvent, JsNetworkKind};
+use ide_core::{IdeError, IdeResult};
+use serde::{Deserialize, Serialize};
+use serde_json::{Value, json};
+use specta::Type;
+use std::collections::BTreeMap;
+use std::path::PathBuf;
+use std::sync::atomic::{AtomicU32, Ordering};
+
+pub(crate) const ADAPTER: &str = "js-debug";
+
+/// Whether `session` debugs a page: the child js-debug starts for a browser launch or attach.
+/// The launch's own session only owns the browser.
+pub(crate) fn is_page(session: &Session) -> bool {
+    session.adapter == ADAPTER
+        && session.parent.is_some()
+        && matches!(session.launch_type.get().map(String::as_str), Some("pwa-chrome" | "pwa-msedge"))
+}
+
+/// Waits until the adapter answered the `launch` of `session`. js-debug sets a page's session
+/// up between `configurationDone` and that answer; a request of its own that arrives then is
+/// answered and has no effect.
+pub(crate) async fn launched(session: &Session) -> bool {
+    let mut launched = session.launched.subscribe();
+    let answered = tokio::time::timeout(REQUEST_TIMEOUT, launched.wait_for(|answered| *answered)).await;
+    matches!(answered, Ok(Ok(_)))
+}
+
+impl DebugManager {
+    /// One of js-debug's requests for pages, sent to the page `s` once its session has started.
+    async fn js_page_request(&self, s: DebugSessionId, command: &str, arguments: Value) -> IdeResult<Value> {
+        let session = self.session(s)?;
+        if !is_page(&session) {
+            return Err(IdeError::unavailable("this debug session is not a page in a browser"));
+        }
+        if !launched(&session).await {
+            return Err(IdeError::unavailable("the page's debug session did not finish starting"));
+        }
+        session
+            .conn
+            .request_timeout(command, arguments, REQUEST_TIMEOUT)
+            .await
+            .map_err(|e| IdeError::unavailable(format!("the JavaScript debugger refused `{command}`: {e}")))
+    }
+
+    /// Breakpoints on events (`listener:click`, `instrumentation:setTimeout`) and on requests
+    /// whose URL contains one of `xhr`. The lists replace the page's previous ones.
+    pub async fn js_set_custom_breakpoints(
+        &self,
+        s: DebugSessionId,
+        ids: Vec<String>,
+        xhr: Vec<String>,
+    ) -> IdeResult<()> {
+        self.js_page_request(s, "setCustomBreakpoints", json!({ "ids": ids, "xhr": xhr })).await?;
+        Ok(())
+    }
+
+    /// Starts recording the page's CPU profile; [`Self::js_stop_profile`] ends it.
+    pub async fn js_start_profile(&self, s: DebugSessionId) -> IdeResult<()> {
+        self.js_page_request(s, "startProfile", json!({ "type": "cpu" })).await?;
+        Ok(())
+    }
+
+    /// Ends the recording and returns a new directory holding it as `page.cpuprofile`
+    /// (what `ide-profiler` reads a directory of).
+    pub async fn js_stop_profile(&self, s: DebugSessionId) -> IdeResult<PathBuf> {
+        let session = self.session(s)?;
+        // js-debug names the file it records into when the recording starts.
+        let Some(recorded) = session.js_profile.lock().take() else {
+            return Err(IdeError::invalid("no CPU profile is being recorded"));
+        };
+        self.js_page_request(s, "stopProfile", json!({})).await?;
+        static HANDED_OVER: AtomicU32 = AtomicU32::new(0);
+        let dir = std::env::temp_dir().join(format!(
+            "openidea-js-profile-{}-{}-{}",
+            std::process::id(),
+            s.0,
+            HANDED_OVER.fetch_add(1, Ordering::Relaxed)
+        ));
+        let copied = tokio::task::spawn_blocking({
+            let dir = dir.clone();
+            move || {
+                std::fs::create_dir_all(&dir)?;
+                std::fs::copy(&recorded, dir.join("page.cpuprofile"))?;
+                // The adapter's own copy is in the system's temporary directory: no use keeping two.
+                let _ = std::fs::remove_file(&recorded);
+                Ok::<_, std::io::Error>(())
+            }
+        })
+        .await
+        .map_err(|e| IdeError::internal(e.to_string()))?;
+        copied.map_err(|e| IdeError::unavailable(format!("the recorded CPU profile cannot be read: {e}")))?;
+        Ok(dir)
+    }
+}
+
+/// The browser events js-debug is asked to pass on (`enableNetworking`'s `mirrorEvents`).
+pub(crate) const NETWORK_EVENTS: [&str; 4] =
+    ["requestWillBeSent", "responseReceived", "loadingFinished", "loadingFailed"];
+
+/// Response bodies shown are cut at this many bytes.
+pub const RESPONSE_BODY_LIMIT: usize = 1_048_576;
+
+/// The body of a response, as text or as the browser's base64 for binary content.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct JsResponseBody {
+    pub body: String,
+    pub base64_encoded: bool,
+    /// The body was longer than [`RESPONSE_BODY_LIMIT`] and is cut there.
+    pub truncated: bool,
+}
+
+fn text(v: &Value, key: &str) -> Option<String> {
+    v.get(key).and_then(Value::as_str).map(str::to_owned)
+}
+
+fn headers(v: &Value) -> BTreeMap<String, String> {
+    v.get("headers")
+        .and_then(Value::as_object)
+        .map(|h| h.iter().filter_map(|(k, v)| Some((k.clone(), v.as_str()?.to_owned()))).collect())
+        .unwrap_or_default()
+}
+
+/// The frame a request is attributed to: the innermost one outside `node_modules`, looked
+/// for through the stacks that scheduled this one (an `await`, a timer), since a request sent
+/// through a library has the library innermost. A stack of library frames only gives its first.
+fn initiator(data: &Value) -> Option<JsInitiator> {
+    let stack = data.pointer("/initiator/stack")?;
+    let frames = |stack: &Value| stack.get("callFrames").and_then(Value::as_array).cloned().unwrap_or_default();
+    let stacks = std::iter::successors(Some(stack), |stack| stack.get("parent")).take(32);
+    let all: Vec<Value> = stacks.flat_map(frames).collect();
+    let own = |frame: &&Value| {
+        frame.get("url").and_then(Value::as_str).is_some_and(|url| !url.is_empty() && !url.contains("/node_modules/"))
+    };
+    let frame = all.iter().find(own).or(all.first())?;
+    let number = |key: &str| frame.get(key).and_then(Value::as_u64).and_then(|n| u32::try_from(n).ok()).unwrap_or(0);
+    Some(JsInitiator {
+        function: text(frame, "functionName").unwrap_or_default(),
+        url: text(frame, "url")?,
+        line: number("lineNumber"),
+        column: number("columnNumber"),
+    })
+}
+
+/// js-debug's `networkEvent` (`{event, data}`, `data` being the browser's own parameters of
+/// that event) as a [`JsNetworkEvent`]; `None` for events the Network view has no use for.
+pub(crate) fn network_event(body: &Value) -> Option<JsNetworkEvent> {
+    let data = body.get("data")?;
+    let kind = match body.get("event").and_then(Value::as_str)? {
+        "requestWillBeSent" => JsNetworkKind::Request,
+        "responseReceived" => JsNetworkKind::Response,
+        "loadingFinished" => JsNetworkKind::Finished,
+        "loadingFailed" => JsNetworkKind::Failed,
+        _ => return None,
+    };
+    let part = match kind {
+        JsNetworkKind::Request => data.get("request"),
+        JsNetworkKind::Response => data.get("response"),
+        _ => None,
+    };
+    let part = part.unwrap_or(&Value::Null);
+    Some(JsNetworkEvent {
+        kind,
+        request_id: text(data, "requestId")?,
+        // Seconds with a fraction.
+        timestamp_ms: (data.get("timestamp").and_then(Value::as_f64).unwrap_or(0.0).max(0.0) * 1000.0).round() as u64,
+        url: text(part, "url"),
+        method: text(part, "method"),
+        resource_type: text(data, "type"),
+        status: part.get("status").and_then(Value::as_u64).and_then(|s| u16::try_from(s).ok()),
+        mime_type: text(part, "mimeType"),
+        headers: headers(part),
+        encoded_length: data.get("encodedDataLength").and_then(Value::as_f64).map(|n| n.max(0.0) as u64),
+        error_text: text(data, "errorText"),
+        initiator: if kind == JsNetworkKind::Request { initiator(data) } else { None },
+    })
+}
+
+/// `networkCall getResponseBody`'s answer, cut at `limit` bytes on a character boundary.
+fn response_body(answer: &Value, limit: usize) -> JsResponseBody {
+    let mut body = text(answer, "body").unwrap_or_default();
+    let truncated = body.len() > limit;
+    if truncated {
+        let mut end = limit;
+        while !body.is_char_boundary(end) {
+            end -= 1;
+        }
+        body.truncate(end);
+    }
+    JsResponseBody {
+        body,
+        base64_encoded: answer.get("base64Encoded").and_then(Value::as_bool).unwrap_or(false),
+        truncated,
+    }
+}
+
+/// The arguments of `enableNetworking`, which has a page report its requests
+/// ([`ide_core::event::DebugEvent::JsNetwork`]). A page session sends it as it starts.
+pub(crate) fn networking_arguments() -> Value {
+    json!({ "mirrorEvents": NETWORK_EVENTS })
+}
+
+impl DebugManager {
+    /// The body of the response to `request_id`, while the browser still has it.
+    pub async fn js_response_body(&self, s: DebugSessionId, request_id: String) -> IdeResult<JsResponseBody> {
+        let call = json!({ "method": "getResponseBody", "params": { "requestId": request_id } });
+        let answer = self.js_page_request(s, "networkCall", call).await?;
+        Ok(response_body(&answer, RESPONSE_BODY_LIMIT))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn event(kind: &str, data: Value) -> Option<ide_core::event::JsNetworkEvent> {
+        network_event(&json!({ "event": kind, "data": data }))
+    }
+
+    #[test]
+    fn a_request_carries_what_was_asked_and_who_asked() {
+        let e = event(
+            "requestWillBeSent",
+            json!({
+                "requestId": "76695.31", "timestamp": 611807.5, "type": "Fetch",
+                "request": { "method": "GET", "url": "http://127.0.0.1:5195/src/main.ts", "headers": { "Accept": "*/*", "X-N": 1 } },
+                "initiator": { "type": "script", "stack": { "callFrames": [
+                    { "functionName": "load", "url": "http://127.0.0.1:5195/src/App.vue", "lineNumber": 9, "columnNumber": 2 }
+                ] } }
+            }),
+        )
+        .unwrap();
+        assert_eq!(e.kind, JsNetworkKind::Request);
+        assert_eq!((e.request_id.as_str(), e.timestamp_ms), ("76695.31", 611_807_500));
+        assert_eq!(e.url.as_deref(), Some("http://127.0.0.1:5195/src/main.ts"));
+        assert_eq!((e.method.as_deref(), e.resource_type.as_deref()), (Some("GET"), Some("Fetch")));
+        // Only text headers are kept.
+        assert_eq!(e.headers.len(), 1);
+        assert_eq!(e.headers["Accept"], "*/*");
+        let from = e.initiator.unwrap();
+        assert_eq!((from.function.as_str(), from.line, from.column), ("load", 9, 2));
+        assert_eq!(from.url, "http://127.0.0.1:5195/src/App.vue");
+    }
+
+    #[test]
+    fn a_request_made_through_a_library_is_asked_by_the_code_that_called_the_library() {
+        let frame = |function: &str, url: &str| json!({ "functionName": function, "url": url, "lineNumber": 1, "columnNumber": 0 });
+        let lib = "http://localhost:5173/node_modules/.vite/deps/http-client.js";
+        let asked_by = |stack: Value| {
+            let data = json!({ "requestId": "1", "timestamp": 1.0, "request": { "method": "GET", "url": "http://localhost/api" },
+                               "initiator": { "type": "script", "stack": stack } });
+            event("requestWillBeSent", data).unwrap().initiator.unwrap().function
+        };
+        // The innermost frame is the library's; the project's caller is further out.
+        let direct = json!({ "callFrames": [frame("dispatch", lib), frame("request", lib), frame("loadItems", "http://localhost:5173/src/api.ts")] });
+        assert_eq!(asked_by(direct), "loadItems");
+        // Across an `await`, the caller is in the stack that scheduled this one.
+        let scheduled = json!({ "callFrames": [frame("dispatch", lib)],
+            "parent": { "callFrames": [frame("then", lib)], "parent": { "callFrames": [frame("onMounted", "http://localhost:5173/src/App.vue")] } } });
+        assert_eq!(asked_by(scheduled), "onMounted");
+        // A library on its own: the frame that sent the request.
+        assert_eq!(asked_by(json!({ "callFrames": [frame("dispatch", lib), frame("poll", lib)] })), "dispatch");
+    }
+
+    #[test]
+    fn a_response_a_finish_and_a_failure_carry_their_outcome() {
+        let response = event(
+            "responseReceived",
+            json!({ "requestId": "7", "timestamp": 2.0, "type": "Script", "response": {
+                "url": "http://localhost/a.js", "status": 200, "mimeType": "text/javascript",
+                "headers": { "Content-Type": "text/javascript" }
+            } }),
+        )
+        .unwrap();
+        assert_eq!(response.kind, JsNetworkKind::Response);
+        assert_eq!((response.status, response.mime_type.as_deref()), (Some(200), Some("text/javascript")));
+        assert_eq!(response.headers["Content-Type"], "text/javascript");
+
+        let finished =
+            event("loadingFinished", json!({ "requestId": "7", "timestamp": 2.5, "encodedDataLength": 1234 })).unwrap();
+        assert_eq!((finished.kind, finished.encoded_length), (JsNetworkKind::Finished, Some(1234)));
+
+        let failed =
+            event("loadingFailed", json!({ "requestId": "8", "timestamp": 3.0, "errorText": "net::ERR_FAILED" }))
+                .unwrap();
+        assert_eq!((failed.kind, failed.error_text.as_deref()), (JsNetworkKind::Failed, Some("net::ERR_FAILED")));
+    }
+
+    #[test]
+    fn events_that_name_no_request_or_are_not_mirrored_are_dropped() {
+        assert!(event("requestWillBeSent", json!({ "timestamp": 1.0 })).is_none());
+        assert!(event("dataReceived", json!({ "requestId": "7", "timestamp": 1.0 })).is_none());
+        assert!(network_event(&json!({ "data": { "requestId": "7" } })).is_none());
+        // A request made by the page's parser has no script behind it.
+        let parser = event(
+            "requestWillBeSent",
+            json!({ "requestId": "9", "timestamp": 1.0, "request": { "method": "GET", "url": "http://localhost/" },
+                    "initiator": { "type": "parser" } }),
+        )
+        .unwrap();
+        assert!(parser.initiator.is_none());
+    }
+
+    #[test]
+    fn a_response_body_is_cut_at_the_limit_on_a_character() {
+        let whole = response_body(&json!({ "body": "héllo", "base64Encoded": false }), 100);
+        assert_eq!((whole.body.as_str(), whole.base64_encoded, whole.truncated), ("héllo", false, false));
+        // `é` is two bytes: a cut inside it backs off to the character before.
+        let cut = response_body(&json!({ "body": "héllo" }), 2);
+        assert_eq!((cut.body.as_str(), cut.truncated), ("h", true));
+        let binary = response_body(&json!({ "body": "AAEC", "base64Encoded": true }), 100);
+        assert!(binary.base64_encoded && !binary.truncated);
+        assert_eq!(response_body(&json!({}), 100).body, "");
+    }
+}
@@ -13,6 +13,8 @@ pub mod attach;
 mod cargo;
 pub mod connection;
 pub mod jdwp;
+mod js_cdp;
+mod js_debug;
 mod jvm_memory;
 pub mod kotlin;
 pub mod kotlin_lsp;
@@ -23,6 +25,8 @@ use connection::{Connection, DapError};
 use futures::future::join_all;
 use ide_core::{DebugSessionId, IdeError, IdeResult, SharedSink};
 use ide_language::LanguageRegistry;
+pub use js_cdp::JsResponseRule;
+pub use js_debug::JsResponseBody;
 pub use jvm_memory::*;
 use parking_lot::Mutex;
 use serde::{Deserialize, Serialize};
@@ -136,6 +140,11 @@ pub struct DebugCapabilities {
    pub jvm_instances: bool,
    /// The session can be asked for a heap dump ([`DebugManager::jvm_heap_dump`]).
    pub jvm_heap: bool,
+    /// The session debugs a page in a browser: js-debug's requests for pages apply
+    /// ([`DebugManager::js_set_custom_breakpoints`]).
+    pub js_page: bool,
+    /// The adapter evaluates expressions while the program runs, without a stack frame.
+    pub live_evaluate: bool,
 }

 /// Result of [`DebugManager::redefine_classes`].
@@ -393,6 +402,16 @@ fn no_session(s: DebugSessionId) -> IdeError {
    IdeError::not_found(format!("no debug session {}", s.0))
 }

+/// The name of a child session: the adapter's, or the parent's when it gives none. js-debug
+/// names a browser page's session after the page the browser starts on, before the URL
+/// loads (`about:blank`, or nothing in a new profile), which says nothing about what is debugged.
+fn child_name(configuration: &Value, parent: &str) -> String {
+    match configuration.get("name").and_then(Value::as_str) {
+        Some(name) if !name.trim().is_empty() && name != "about:blank" => name.to_owned(),
+        _ => parent.to_owned(),
+    }
+}
+
 /// Builds the `launch`/`attach` arguments: our fields first, then `extra_json` merged on top.
 pub fn launch_arguments(config: &LaunchConfig) -> IdeResult<Value> {
    // VS Code puts `type`, `request` and `name` in the arguments; js-debug picks launch
@@ -580,6 +599,8 @@ pub(crate) fn capabilities_from(caps: &Value) -> DebugCapabilities {
        jvm_memory: false,
        jvm_instances: false,
        jvm_heap: false,
+        js_page: false,
+        live_evaluate: false,
    }
 }

@@ -589,6 +610,8 @@ pub(crate) fn session_capabilities(session: &Session) -> DebugCapabilities {
    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.js_page = js_debug::is_page(session);
+    caps.live_evaluate = session.adapter == js_debug::ADAPTER;
    caps
 }

@@ -744,6 +767,9 @@ impl DebugManager {
            .unwrap_or_else(|| std::env::current_dir().unwrap_or_else(|_| "/".into()));
        let dbg = adapter::find_config(&self.languages, &config.adapter)
            .ok_or_else(|| IdeError::unavailable(format!("unknown debug adapter `{}`", config.adapter)))?;
+        if config.adapter == "js-debug" {
+            adapter::set_browser_profile(&mut arguments, &cwd);
+        }
        let mut spec = adapter::resolve(&dbg, cwd.clone());
        if config.adapter == kotlin::ADAPTER
            && let Some(home) = arguments
@@ -872,8 +898,7 @@ impl DebugManager {
        request: String,
        configuration: Value,
    ) -> IdeResult<()> {
-        let name =
-            configuration.get("name").and_then(Value::as_str).map(str::to_owned).unwrap_or_else(|| parent.name.clone());
+        let name = child_name(&configuration, &parent.name);
        let mut configuration = configuration;
        if let Some(obj) = configuration.as_object_mut() {
            obj.entry("request").or_insert_with(|| request.clone().into());
@@ -921,6 +946,9 @@ impl DebugManager {
            .flatten();
        let session =
            Arc::new(Session::new(id, owner, name, adapter_name, parent, request, conn, spec, io.port, io.child));
+        if let Some(launch_type) = arguments.get("type").and_then(Value::as_str) {
+            let _ = session.launch_type.set(launch_type.to_owned());
+        }
        // rdbg execs the debuggee in its own process and sends no DAP process event.
        if let Some(pid) = rdbg_pid {
            session.debuggee_pid.store(i64::from(pid), Ordering::Release);
@@ -1155,6 +1183,22 @@ impl DebugManager {
                reply.await.unwrap_or(Err(DapError::Closed))?;
            }
        }
+        s.launched.send_replace(true);
+        // A page reports its requests from here on. This is the earliest js-debug takes the
+        // request (before its answer to `launch` the page has no adapter and the request is
+        // never answered), and the page is already loading: its document and first scripts
+        // are not in the list.
+        if js_debug::is_page(s) {
+            let answer = s.conn.send_request("enableNetworking", js_debug::networking_arguments())?;
+            let session = s.clone();
+            // Not waited for here: the page runs on. A refusal is told to the Network view,
+            // which would otherwise wait for requests that never come.
+            tokio::spawn(async move {
+                if matches!(answer.await, Ok(Err(_))) {
+                    session.emit(ide_core::event::DebugEvent::JsNetworkUnavailable);
+                }
+            });
+        }
        if let Some(link) = s.jdwp_link.lock().as_ref() {
            link.release();
        }
@@ -57,6 +57,8 @@ pub(crate) struct Session {
    pub job: Mutex<Option<ide_core::process::Job>>,
    /// Set once `configurationDone` was sent; breakpoint updates go out live after that.
    pub configured: AtomicBool,
+    /// Set once the adapter answered `launch` / `attach`, after the configuration.
+    pub launched: watch::Sender<bool>,
    pub initialized: watch::Sender<bool>,
    pub startup_cancel: ide_core::CancellationToken,
    pub output_drained: watch::Sender<bool>,
@@ -89,6 +91,14 @@ pub(crate) struct Session {
    progress: Mutex<HashMap<String, TaskId>>,
    /// Relay between a Kotlin adapter and its JVM. Dropping it closes both sockets.
    pub jdwp_link: parking_lot::Mutex<Option<ide_jdwp::JdwpLink>>,
+    /// The `type` of the launch or attach request (js-debug's `pwa-node`, `pwa-chrome`); a child
+    /// session's comes from the configuration the adapter started it with.
+    pub launch_type: std::sync::OnceLock<String>,
+    /// The response rules of a page once a connection applies them (`js_cdp::serve`).
+    /// Dropped with the session, which switches the browser's interception off.
+    pub js_overrides: tokio::sync::Mutex<Option<tokio::sync::watch::Sender<Vec<crate::JsResponseRule>>>>,
+    /// The file js-debug records the page's CPU profile into, while one is being recorded.
+    pub js_profile: parking_lot::Mutex<Option<std::path::PathBuf>>,
    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<()>,
@@ -230,6 +240,7 @@ impl Session {
            #[cfg(windows)]
            job: Mutex::new(job),
            configured: AtomicBool::new(false),
+            launched: watch::channel(false).0,
            initialized: watch::channel(false).0,
            startup_cancel: ide_core::CancellationToken::new(),
            output_drained: watch::channel(true).0,
@@ -248,6 +259,9 @@ impl Session {
            resolved_paths: Mutex::new(HashMap::new()),
            progress: Mutex::new(HashMap::new()),
            jdwp_link: parking_lot::Mutex::new(None),
+            launch_type: std::sync::OnceLock::new(),
+            js_overrides: tokio::sync::Mutex::new(None),
+            js_profile: parking_lot::Mutex::new(None),
            jvm_inspector: parking_lot::Mutex::new(None),
            inspect_lock: tokio::sync::Mutex::default(),
            ended: ide_core::CancellationToken::new(),
@@ -467,10 +481,7 @@ impl Session {
            let _ = c.start_kill();
        }
        if let Some(mut program) = self.program.lock().take() {
-            let _ = program.child.kill();
-            let _ = std::thread::Builder::new().name("openidea-debug-reap".into()).spawn(move || {
-                let _ = program.child.wait();
-            });
+            program.kill();
        }
    }
 }
@@ -567,7 +578,7 @@ fn launch_groups(s: &Session) -> Vec<libc::pid_t> {
    for child in s.debuggees.lock().iter() {
        push(child.id());
    }
-    push(s.program.lock().as_ref().and_then(|p| p.child.process_id()));
+    push(s.program.lock().as_ref().and_then(ProgramTerminal::process_id));
    groups.retain(|g| *g > 0);
    groups
 }
@@ -832,6 +843,16 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
                .map(|a| a.iter().filter_map(Value::as_str).map(str::to_owned).collect())
                .unwrap_or_default(),
        }),
+        // js-debug, after `enableNetworking`.
+        "networkEvent" => {
+            if let Some(event) = crate::js_debug::network_event(&body) {
+                s.emit(DebugEvent::JsNetwork { event });
+            }
+        }
+        // js-debug, after `startProfile`: where it records the profile.
+        "profileStarted" => {
+            *s.js_profile.lock() = str_("file").map(std::path::PathBuf::from);
+        }
        _ => tracing::trace!("dap: ignored event {event}"),
    }
 }
@@ -861,7 +882,11 @@ fn on_reverse_request(mgr: &Arc<DebugManager>, s: &Arc<Session>, seq: i64, comma
 /// A `runInTerminal` program and the pseudo-terminal it runs in.
 pub(crate) struct ProgramTerminal {
    writer: ide_core::input::InputWriter,
-    child: Box<dyn portable_pty::Child + Send + Sync>,
+    killer: Box<dyn portable_pty::ChildKiller + Send + Sync>,
+    #[cfg_attr(not(unix), allow(dead_code))]
+    pid: Option<u32>,
+    /// Set once the program has exited and been reaped.
+    exited: Arc<AtomicBool>,
    _master: Box<dyn portable_pty::MasterPty + Send>,
 }

@@ -869,6 +894,29 @@ impl ProgramTerminal {
    pub(crate) fn write(&mut self, text: &str) -> std::io::Result<()> {
        self.writer.write(text.as_bytes())
    }
+
+    /// The program's process id while it runs.
+    #[cfg_attr(not(unix), allow(dead_code))]
+    pub(crate) fn process_id(&self) -> Option<u32> {
+        if self.exited.load(Ordering::Acquire) { None } else { self.pid }
+    }
+
+    pub(crate) fn kill(&mut self) {
+        // After the reap the pid may belong to another process.
+        if !self.exited.load(Ordering::Acquire) {
+            let _ = self.killer.kill();
+        }
+    }
+}
+
+/// Reaps the program as soon as it exits. Until then it stays a zombie that `kill(pid, 0)` still
+/// finds: js-debug polls the `processId` it was given and keeps the session (and its terminal)
+/// open while that process looks alive, and Stop would wait for it as for a running program.
+fn reap_on_exit(mut child: Box<dyn portable_pty::Child + Send + Sync>, exited: Arc<AtomicBool>) {
+    let _ = std::thread::Builder::new().name("openidea-debug-reap".into()).spawn(move || {
+        let _ = child.wait();
+        exited.store(true, Ordering::Release);
+    });
 }

 /// `runInTerminal`: starts the debuggee on a pseudo-terminal, as an IDE terminal would (CodeLLDB
@@ -955,8 +1003,12 @@ pub(crate) fn run_in_terminal(s: &Arc<Session>, args: &Value) -> Result<Value, S
        #[cfg(unix)]
        wait_readable,
    );
-    if let Some(mut previous) = s.program.lock().replace(ProgramTerminal { writer, child, _master: pair.master }) {
-        let _ = previous.child.kill();
+    let killer = child.clone_killer();
+    let exited = Arc::new(AtomicBool::new(false));
+    reap_on_exit(child, exited.clone());
+    let program = ProgramTerminal { writer, killer, pid, exited, _master: pair.master };
+    if let Some(mut previous) = s.program.lock().replace(program) {
+        previous.kill();
    }
    s.owner.sink.emit(IdeEvent::Debug { session: s.id, event: DebugEvent::ProgramInput });
    Ok(json!({ "processId": pid }))
@@ -1325,4 +1377,29 @@ mod tests {
        assert_eq!(parse_jdwp_port("Listening for transport dt_socket at address: [::1]:51234"), Some(51234));
        assert_eq!(parse_jdwp_port("unrelated output"), None);
    }
+
+    /// js-debug polls the `runInTerminal` pid with `kill(pid, 0)`; an unreaped zombie answers it as
+    /// a live process and keeps the session open after the program ends.
+    #[cfg(unix)]
+    #[test]
+    fn a_terminal_program_is_reaped_when_it_exits() {
+        use portable_pty::{CommandBuilder, PtySize, native_pty_system};
+        use std::sync::Arc;
+        use std::sync::atomic::{AtomicBool, Ordering};
+        let pair =
+            native_pty_system().openpty(PtySize { rows: 24, cols: 80, pixel_width: 0, pixel_height: 0 }).unwrap();
+        let mut cmd = CommandBuilder::new("/bin/sh");
+        cmd.args(["-c", "exit 0"]);
+        let child = pair.slave.spawn_command(cmd).unwrap();
+        let pid = child.process_id().unwrap() as libc::pid_t;
+        let exited = Arc::new(AtomicBool::new(false));
+        super::reap_on_exit(child, exited.clone());
+        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+        while !exited.load(Ordering::Acquire) {
+            assert!(std::time::Instant::now() < deadline, "program was not reaped");
+            std::thread::sleep(std::time::Duration::from_millis(10));
+        }
+        // SAFETY: signal 0 only checks whether the process exists.
+        assert_eq!(unsafe { libc::kill(pid, 0) }, -1);
+    }
 }
@@ -146,6 +146,10 @@ struct Script {
    delay_initialize: Option<Duration>,
    initialized_delay: Duration,
    launch_delay: Duration,
+    /// Answer a child session's `launch` this long after its `configurationDone`, reading
+    /// requests meanwhile. Like js-debug, one of `accept` that arrives in between is answered
+    /// and has no effect: the log gets a `dropped` entry for it.
+    child_launch_delay: Duration,
    /// Leave startup pending before `initialized` (false) or after configuration (true).
    pending_startup: Option<bool>,
    startup_error: Option<&'static str>,
@@ -154,8 +158,15 @@ struct Script {
    /// `launch`, and a `configurationDone` sent while it runs is refused with `notStopped`.
    gdb15_starts_at_launch: bool,
    launch_after_configuration: bool,
+    /// Requests of the adapter's own (js-debug's `setCustomBreakpoints`…) answered with an empty body.
+    accept: &'static [&'static str],
+    /// Requests of the adapter's own answered with a body and followed by events.
+    custom: Option<fn(&Value) -> Option<CustomReply>>,
 }

+/// The answer to a request of the adapter's own: the response body, then events (name, body).
+type CustomReply = (Value, Vec<(&'static str, Value)>);
+
 impl Default for Script {
    fn default() -> Self {
        Self {
@@ -181,11 +192,14 @@ impl Default for Script {
            delay_initialize: None,
            initialized_delay: Duration::ZERO,
            launch_delay: Duration::ZERO,
+            child_launch_delay: Duration::ZERO,
            pending_startup: None,
            startup_error: None,
            close_during_startup: false,
            gdb15_starts_at_launch: false,
            launch_after_configuration: false,
+            accept: &[],
+            custom: None,
        }
    }
 }
@@ -218,10 +232,15 @@ impl AdapterLauncher for FakeLauncher {
 }

 async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream: S, log: Log, script: Script) {
-    let (r, mut w) = tokio::io::split(stream);
+    let (r, w) = tokio::io::split(stream);
+    // Shared with the task that answers a child's `launch` late (`child_launch_delay`).
+    let w = Arc::new(tokio::sync::Mutex::new(w));
    let mut r = BufReader::new(r);
    let mut seq = 1000;
    let mut pending_launch: Option<i64> = None;
+    let mut child = false;
+    // Between `configurationDone` and the answer to `launch`.
+    let starting = Arc::new(std::sync::atomic::AtomicBool::new(false));
    let mut held: Vec<Value> = Vec::new();
    let mut stopped = false;
    let mut running = false;
@@ -230,7 +249,7 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
            let mut v: Value = $v;
            seq += 1;
            v["seq"] = seq.into();
-            framing::write_message(&mut w, &serde_json::to_vec(&v).unwrap()).await.unwrap();
+            framing::write_message(&mut *w.lock().await, &serde_json::to_vec(&v).unwrap()).await.unwrap();
        }};
    }
    macro_rules! ok {
@@ -292,6 +311,7 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                    continue;
                }
                pending_launch = msg["seq"].as_i64();
+                child = msg["arguments"]["isChild"] == true;
                if let Some(args) = &script.run_in_terminal {
                    send!(
                        json!({"type": "request", "command": "runInTerminal", "arguments": {"kind": "integrated", "args": args, "cwd": std::env::temp_dir()}})
@@ -299,7 +319,8 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                }
                if script.start_debugging && msg["arguments"]["isChild"] != true {
                    send!(
-                        json!({"type": "request", "command": "startDebugging", "arguments": {"request": "launch", "configuration": {"name": "child", "isChild": true}}})
+                        // Like js-debug, the child's configuration repeats the launch's `type`.
+                        json!({"type": "request", "command": "startDebugging", "arguments": {"request": "launch", "configuration": {"name": "child", "isChild": true, "type": msg["arguments"]["type"]}}})
                    );
                }
                if script.pending_startup != Some(false) {
@@ -378,7 +399,21 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
                }
                tokio::time::sleep(script.launch_delay).await;
                if let Some(l) = pending_launch.take() {
-                    send!(json!({"type": "response", "request_seq": l, "command": "launch", "success": true}));
+                    let answer = json!({"type": "response", "request_seq": l, "command": "launch", "success": true});
+                    if child && !script.child_launch_delay.is_zero() {
+                        starting.store(true, Ordering::Release);
+                        let (w, starting, delay) = (w.clone(), starting.clone(), script.child_launch_delay);
+                        tokio::spawn(async move {
+                            tokio::time::sleep(delay).await;
+                            let mut answer = answer;
+                            answer["seq"] = 999_999.into();
+                            let _ = framing::write_message(&mut *w.lock().await, &serde_json::to_vec(&answer).unwrap())
+                                .await;
+                            starting.store(false, Ordering::Release);
+                        });
+                    } else {
+                        send!(answer);
+                    }
                }
                if let Some(pid) = script.debuggee_pid {
                    let event = if script.java_process_id {
@@ -474,9 +509,25 @@ async fn fake_adapter<S: AsyncRead + AsyncWrite + Unpin + Send + 'static>(stream
            }
            "disconnect" => {
                ok!(msg, Value::Null);
-                let _ = w.shutdown().await;
+                let _ = w.lock().await.shutdown().await;
                break;
            }
+            other if script.accept.contains(&other) => {
+                if starting.load(Ordering::Acquire) {
+                    log.lock().push(json!({"type": "dropped", "command": other}));
+                }
+                ok!(msg, json!({}))
+            }
+            other if script.custom.and_then(|custom| custom(&msg)).is_some() => {
+                if starting.load(Ordering::Acquire) {
+                    log.lock().push(json!({"type": "dropped", "command": other}));
+                }
+                let (body, events) = script.custom.and_then(|custom| custom(&msg)).unwrap();
+                ok!(msg, body);
+                for (event, body) in events {
+                    send!(json!({"type": "event", "event": event, "body": body}));
+                }
+            }
            other => send!(
                json!({"type": "response", "request_seq": msg["seq"], "command": other, "success": false, "message": "unsupported"})
            ),
@@ -905,6 +956,298 @@ async fn blocked_program_input_does_not_hold_up_shutdown() {
    assert!(h.manager.send_input(session, "later").is_err());
 }

+fn js_config(launch_type: &str) -> LaunchConfig {
+    LaunchConfig {
+        adapter: "js-debug".into(),
+        program: None,
+        args: Vec::new(),
+        extra_json: Some(format!(r#"{{"type": "{launch_type}"}}"#)),
+        ..config()
+    }
+}
+
+/// The session the adapter started under `parent`.
+async fn child_of(h: &Harness, parent: DebugSessionId) -> DebugSessionId {
+    for _ in 0..200 {
+        if let Some(child) = h.manager.sessions(Some("main")).into_iter().find(|s| s.parent == Some(parent)) {
+            return child.id;
+        }
+        tokio::time::sleep(Duration::from_millis(10)).await;
+    }
+    panic!("no child session of {parent:?}");
+}
+
+#[tokio::test]
+async fn a_browser_page_session_has_the_page_capability() {
+    let h = harness(Script { start_debugging: true, ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = h.manager.capabilities(child_of(&h, browser).await).unwrap();
+    assert!(page.js_page && page.live_evaluate);
+    assert!(!h.manager.capabilities(browser).unwrap().js_page, "the launch itself is not a page");
+
+    let node = h.start(js_config("pwa-node")).await.unwrap();
+    let process = h.manager.capabilities(child_of(&h, node).await).unwrap();
+    assert!(!process.js_page && process.live_evaluate);
+
+    let python = h.start(config()).await.unwrap();
+    let script = h.manager.capabilities(child_of(&h, python).await).unwrap();
+    assert!(!script.js_page && !script.live_evaluate);
+}
+
+#[tokio::test]
+async fn custom_breakpoints_are_sent_to_a_page_and_refused_elsewhere() {
+    let h = harness(Script { start_debugging: true, accept: &["setCustomBreakpoints"], ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+    h.manager.js_set_custom_breakpoints(page, vec!["listener:click".into()], vec!["api/".into()]).await.unwrap();
+    assert_eq!(requests(&h, "setCustomBreakpoints"), [json!({"ids": ["listener:click"], "xhr": ["api/"]})]);
+
+    let not_a_page = h.manager.js_set_custom_breakpoints(browser, Vec::new(), Vec::new()).await.unwrap_err();
+    assert_eq!(not_a_page.kind, ide_core::error::ErrorKind::Unavailable);
+
+    // A js-debug build without the request.
+    let old = harness(Script { start_debugging: true, ..Script::default() });
+    let browser = old.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&old, browser).await;
+    let refused = old.manager.js_set_custom_breakpoints(page, Vec::new(), Vec::new()).await.unwrap_err();
+    assert_eq!(refused.kind, ide_core::error::ErrorKind::Unavailable);
+}
+
+/// js-debug answers a request of its own that reaches a page after `configurationDone` and
+/// before the page's `launch` is answered, and then does nothing with it.
+#[tokio::test]
+async fn a_page_gets_its_requests_once_its_session_has_started() {
+    let h = harness(Script {
+        start_debugging: true,
+        accept: &["setCustomBreakpoints"],
+        child_launch_delay: Duration::from_millis(150),
+        ..Script::default()
+    });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+    // Past the page's `configurationDone`, with its `launch` still unanswered.
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    h.manager.js_set_custom_breakpoints(page, vec!["listener:click".into()], Vec::new()).await.unwrap();
+    assert_eq!(requests(&h, "setCustomBreakpoints"), [json!({"ids": ["listener:click"], "xhr": []})]);
+    let dropped = h.log.lock().iter().filter(|m| m["type"] == "dropped").count();
+    assert_eq!(dropped, 0, "the request reached the page before it took requests");
+}
+
+/// js-debug's network requests: `enableNetworking` is followed by one mirrored browser event.
+fn network_adapter(msg: &Value) -> Option<CustomReply> {
+    match msg["command"].as_str()? {
+        "enableNetworking" => Some((
+            json!({}),
+            vec![(
+                "networkEvent",
+                json!({ "event": "requestWillBeSent", "data": {
+                    "requestId": "7", "timestamp": 1.5, "type": "Fetch",
+                    "request": { "method": "GET", "url": "http://localhost:5173/api/items", "headers": {} }
+                } }),
+            )],
+        )),
+        "networkCall" => Some((json!({ "body": "é".repeat(600_000), "base64Encoded": false }), Vec::new())),
+        _ => None,
+    }
+}
+
+#[tokio::test]
+async fn a_page_reports_its_requests_and_their_bodies() {
+    let h = harness(Script {
+        start_debugging: true,
+        custom: Some(network_adapter),
+        child_launch_delay: Duration::from_millis(100),
+        ..Script::default()
+    });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+
+    // Recording is asked for by the session itself, as soon as js-debug takes the request:
+    // once it has answered the page's `launch` (before that, the request is never answered).
+    let DebugEvent::JsNetwork { event } = h.wait_event(|e| matches!(e, DebugEvent::JsNetwork { .. })).await else {
+        unreachable!()
+    };
+    assert_eq!(
+        requests(&h, "enableNetworking"),
+        [json!({ "mirrorEvents": ["requestWillBeSent", "responseReceived", "loadingFinished", "loadingFailed"] })]
+    );
+    let dropped = h.log.lock().iter().filter(|m| m["type"] == "dropped").count();
+    assert_eq!(dropped, 0, "recording was asked for before the page took requests");
+    assert_eq!((event.request_id.as_str(), event.timestamp_ms), ("7", 1500));
+    assert_eq!(event.url.as_deref(), Some("http://localhost:5173/api/items"));
+
+    let body = h.manager.js_response_body(page, "7".into()).await.unwrap();
+    assert_eq!(requests(&h, "networkCall"), [json!({ "method": "getResponseBody", "params": { "requestId": "7" } })]);
+    // 1.2 MB of two-byte characters: cut at the limit, on a character.
+    assert!(body.truncated && !body.base64_encoded);
+    assert_eq!(body.body.len(), 1_048_576);
+    assert!(body.body.chars().all(|c| c == 'é'));
+
+    assert_eq!(
+        h.manager.js_response_body(browser, "7".into()).await.unwrap_err().kind,
+        ide_core::error::ErrorKind::Unavailable
+    );
+
+    // A Node.js program is not a page: nothing is asked of it.
+    let node = h.start(js_config("pwa-node")).await.unwrap();
+    child_of(&h, node).await;
+    h.wait_event(|e| matches!(e, DebugEvent::Stopped { .. })).await;
+    assert_eq!(requests(&h, "enableNetworking").len(), 1);
+}
+
+#[tokio::test]
+async fn a_page_whose_requests_the_adapter_does_not_report_says_so() {
+    // A js-debug build without `enableNetworking`.
+    let h = harness(Script { start_debugging: true, ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    child_of(&h, browser).await;
+    h.wait_event(|e| matches!(e, DebugEvent::JsNetworkUnavailable)).await;
+}
+
+/// Where the fake adapter says its CDP proxy listens (`requestCDPProxy`).
+static CDP_PROXY_PORT: std::sync::atomic::AtomicU16 = std::sync::atomic::AtomicU16::new(0);
+
+fn proxy_adapter(msg: &Value) -> Option<CustomReply> {
+    let port = CDP_PROXY_PORT.load(std::sync::atomic::Ordering::Relaxed);
+    (msg["command"] == "requestCDPProxy")
+        .then(|| (json!({ "host": "127.0.0.1", "port": port, "path": "/session" }), Vec::new()))
+}
+
+#[tokio::test]
+async fn response_overrides_reach_the_page_through_the_adapters_proxy() {
+    use crate::js_cdp::tests::{next, proxy, rule};
+    let (url, mut received, _events) = proxy().await;
+    let port: u16 = url.trim_start_matches("ws://127.0.0.1:").trim_end_matches("/session").parse().unwrap();
+    CDP_PROXY_PORT.store(port, std::sync::atomic::Ordering::Relaxed);
+
+    let h = harness(Script {
+        start_debugging: true,
+        custom: Some(proxy_adapter),
+        child_launch_delay: Duration::from_millis(150),
+        ..Script::default()
+    });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+
+    // Rules that are there as the page starts wait until its session takes requests.
+    tokio::time::sleep(Duration::from_millis(50)).await;
+    h.manager.js_set_response_overrides(page, vec![rule("api/items", 200, "[]")]).await.unwrap();
+    let dropped = h.log.lock().iter().filter(|m| m["type"] == "dropped").count();
+    assert_eq!(dropped, 0, "the proxy was asked for before the page took requests");
+    assert_eq!(next(&mut received).await.0, "JsDebug.subscribe");
+    assert_eq!(
+        next(&mut received).await,
+        ("Fetch.enable".into(), json!({ "patterns": [{ "urlPattern": "*api/items*", "requestStage": "Request" }] }))
+    );
+    // Changed rules go over the connection that is open: the proxy is asked for once.
+    h.manager.js_set_response_overrides(page, vec![rule("api/users", 200, "[]")]).await.unwrap();
+    assert_eq!(next(&mut received).await.1["patterns"][0]["urlPattern"], "*api/users*");
+    assert_eq!(requests(&h, "requestCDPProxy").len(), 1);
+
+    h.manager.js_set_response_overrides(page, Vec::new()).await.unwrap();
+    assert_eq!(next(&mut received).await.0, "Fetch.disable");
+    // A rule switched back on.
+    h.manager.js_set_response_overrides(page, vec![rule("api/items", 200, "[]")]).await.unwrap();
+    assert_eq!(next(&mut received).await.0, "Fetch.enable");
+    assert_eq!(requests(&h, "requestCDPProxy").len(), 1);
+
+    let not_a_page = h.manager.js_set_response_overrides(browser, vec![rule("api", 200, "")]).await.unwrap_err();
+    assert_eq!(not_a_page.kind, ide_core::error::ErrorKind::Unavailable);
+}
+
+#[tokio::test]
+async fn response_overrides_are_unavailable_without_the_adapters_proxy() {
+    use crate::js_cdp::tests::rule;
+    let h = harness(Script { start_debugging: true, ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+    let refused = h.manager.js_set_response_overrides(page, vec![rule("api", 200, "")]).await.unwrap_err();
+    assert_eq!(refused.kind, ide_core::error::ErrorKind::Unavailable);
+    // Nothing to switch off is not an error.
+    h.manager.js_set_response_overrides(page, Vec::new()).await.unwrap();
+}
+
+/// A port nothing listens on, which the fake adapter gives as its CDP proxy.
+static DEAD_PROXY_PORT: std::sync::atomic::AtomicU16 = std::sync::atomic::AtomicU16::new(0);
+
+fn dead_proxy_adapter(msg: &Value) -> Option<CustomReply> {
+    let port = DEAD_PROXY_PORT.load(std::sync::atomic::Ordering::Relaxed);
+    (msg["command"] == "requestCDPProxy")
+        .then(|| (json!({ "host": "127.0.0.1", "port": port, "path": "/session" }), Vec::new()))
+}
+
+#[tokio::test]
+async fn response_overrides_that_cannot_reach_the_browser_are_an_error() {
+    use crate::js_cdp::tests::rule;
+    let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+    DEAD_PROXY_PORT.store(listener.local_addr().unwrap().port(), std::sync::atomic::Ordering::Relaxed);
+    drop(listener);
+
+    let h = harness(Script { start_debugging: true, custom: Some(dead_proxy_adapter), ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+    let unreachable = h.manager.js_set_response_overrides(page, vec![rule("api", 200, "")]).await.unwrap_err();
+    assert_eq!(unreachable.kind, ide_core::error::ErrorKind::Unavailable);
+    // The next rules try again instead of going to a connection that never was.
+    let again = h.manager.js_set_response_overrides(page, vec![rule("api", 200, "")]).await.unwrap_err();
+    assert_eq!(again.kind, ide_core::error::ErrorKind::Unavailable);
+    assert_eq!(requests(&h, "requestCDPProxy").len(), 2);
+}
+
+/// The file the fake adapter says it records a CPU profile into (`profileStarted`).
+static PROFILE_FILE: parking_lot::Mutex<String> = parking_lot::Mutex::new(String::new());
+
+fn profiling_adapter(msg: &Value) -> Option<CustomReply> {
+    match msg["command"].as_str()? {
+        "startProfile" => {
+            Some((json!({}), vec![("profileStarted", json!({ "file": *PROFILE_FILE.lock(), "type": "cpu" }))]))
+        }
+        "stopProfile" => Some((json!({}), vec![("profilerStateUpdate", json!({ "label": "", "running": false }))])),
+        _ => None,
+    }
+}
+
+#[tokio::test]
+async fn a_pages_cpu_profile_is_handed_over_as_a_cpuprofile_file() {
+    let recorded = std::env::temp_dir().join(format!("openidea-dap-profile-{}", std::process::id()));
+    std::fs::write(&recorded, r#"{"nodes":[],"samples":[]}"#).unwrap();
+    *PROFILE_FILE.lock() = recorded.to_string_lossy().into_owned();
+
+    let h = harness(Script { start_debugging: true, custom: Some(profiling_adapter), ..Script::default() });
+    let browser = h.start(js_config("pwa-chrome")).await.unwrap();
+    let page = child_of(&h, browser).await;
+
+    // Nothing is being recorded yet.
+    let idle = h.manager.js_stop_profile(page).await.unwrap_err();
+    assert_eq!(idle.kind, ide_core::error::ErrorKind::InvalidInput);
+
+    h.manager.js_start_profile(page).await.unwrap();
+    assert_eq!(requests(&h, "startProfile"), [json!({ "type": "cpu" })]);
+    let dir = h.manager.js_stop_profile(page).await.unwrap();
+    assert_eq!(requests(&h, "stopProfile").len(), 1);
+    let files: Vec<_> = std::fs::read_dir(&dir).unwrap().map(|e| e.unwrap().file_name()).collect();
+    assert_eq!(files, ["page.cpuprofile"]);
+    assert_eq!(std::fs::read_to_string(dir.join("page.cpuprofile")).unwrap(), r#"{"nodes":[],"samples":[]}"#);
+    // One recording is handed over once.
+    assert_eq!(h.manager.js_stop_profile(page).await.unwrap_err().kind, ide_core::error::ErrorKind::InvalidInput);
+
+    // The adapter's file isn't there when it is asked for (the hand-over above took the first one).
+    assert!(!recorded.exists());
+    h.manager.js_start_profile(page).await.unwrap();
+    assert_eq!(h.manager.js_stop_profile(page).await.unwrap_err().kind, ide_core::error::ErrorKind::Unavailable);
+
+    assert_eq!(h.manager.js_start_profile(browser).await.unwrap_err().kind, ide_core::error::ErrorKind::Unavailable);
+    let _ = std::fs::remove_dir_all(dir);
+}
+
+#[test]
+fn a_child_session_is_named_by_the_adapter_unless_it_is_a_blank_page() {
+    assert_eq!(child_name(&json!({ "name": "server.js [4120]" }), "Server"), "server.js [4120]");
+    assert_eq!(child_name(&json!({ "name": "about:blank" }), "Shop in Chrome"), "Shop in Chrome");
+    assert_eq!(child_name(&json!({ "name": "" }), "Shop in Chrome"), "Shop in Chrome");
+    assert_eq!(child_name(&json!({}), "Shop in Chrome"), "Shop in Chrome");
+}
+
 #[test]
 fn launch_arguments_merge_and_defaults() {
    let mut c = config();
@@ -324,6 +324,17 @@ fn group_foreign_keys(rows: Vec<Vec<Option<String>>>, tables: &[CompletionTable]
 /// Connection target: a data source id (its configured database), or
 /// `<id>:<database>` for another database of the same server. Data source ids
 /// never contain `:`.
+/// Snowflake is HTTPS to a named host: a tunnel's local end cannot pass its certificate check.
+fn tunneled(driver: DbDriver) -> bool {
+    !matches!(driver, DbDriver::Sqlite | DbDriver::Snowflake)
+}
+
+/// The database host and port the SSH host forwards to.
+fn tunnel_target(source: &DataSource) -> (&str, u16) {
+    let port = source.port.or(source.driver.default_port()).unwrap_or_default();
+    (if source.host.trim().is_empty() { "localhost" } else { source.host.trim() }, port)
+}
+
 pub fn split_target(target: &str) -> (&str, Option<&str>) {
    match target.split_once(':') {
        Some((id, db)) if !db.is_empty() => (id, Some(db)),
@@ -655,9 +666,7 @@ impl DbManager {
        ssh_secret: Option<String>,
        shared: bool,
    ) -> IdeResult<(DataSource, Option<Arc<Tunnel>>)> {
-        // Snowflake is HTTPS to a named host: a tunnel's local end cannot pass its certificate check.
-        let tunneled = !matches!(source.driver, DbDriver::Sqlite | DbDriver::Snowflake);
-        let Some(ssh) = source.ssh.as_ref().filter(|s| s.enabled && tunneled) else {
+        let Some(ssh) = source.ssh.as_ref().filter(|s| s.enabled && tunneled(source.driver)) else {
            return Ok((source.clone(), None));
        };
        let local = |t: &Tunnel| DataSource { host: "127.0.0.1".into(), port: Some(t.port()), ..source.clone() };
@@ -668,8 +677,25 @@ impl DbManager {
                return Ok((local(&t), Some(t)));
            }
        }
+        let session = self.ssh_session(source, ssh, ssh_secret).await?;
+        let (target_host, target_port) = tunnel_target(source);
+        let t = Arc::new(Tunnel::open(session, target_host, target_port).await?);
+        if shared {
+            self.tunnels.lock().insert(source.id.clone(), t.clone());
+        }
+        Ok((local(&t), Some(t)))
+    }
+
+    /// The SSH session the tunnel of `source` goes through: its shared SSH configuration's, or one
+    /// opened with the settings typed in the data source.
+    async fn ssh_session(
+        &self,
+        source: &DataSource,
+        ssh: &DbSsh,
+        ssh_secret: Option<String>,
+    ) -> IdeResult<Arc<ide_ssh::Session>> {
        let config = ssh.config.trim();
-        let session = if config.is_empty() {
+        Ok(if config.is_empty() {
            let secret = match ssh_secret {
                Some(s) => Some(s),
                None => self.secret(source, secrets::ssh_key(&source.id), ssh.save_secret).await,
@@ -688,14 +714,22 @@ impl DbManager {
                self.ssh.set_secret(config, Some(s), save);
            }
            self.ssh.session(config).await?
-        };
-        let target_port = source.port.or(source.driver.default_port()).unwrap_or_default();
-        let target_host = if source.host.trim().is_empty() { "localhost" } else { source.host.trim() };
-        let t = Arc::new(Tunnel::open(session, target_host, target_port).await?);
-        if shared {
-            self.tunnels.lock().insert(source.id.clone(), t.clone());
-        }
-        Ok((local(&t), Some(t)))
+        })
+    }
+
+    /// Data Source › SSH/SSL › Test SSH Tunnel: logs in to the SSH host and checks that it reaches
+    /// the database host and port, without logging in to the database.
+    pub async fn test_tunnel(&self, source: &DataSource, ssh_secret: Option<String>) -> IdeResult<String> {
+        let source = &source.resolved()?;
+        let ssh = source
+            .ssh
+            .as_ref()
+            .filter(|s| s.enabled && tunneled(source.driver))
+            .ok_or_else(|| IdeError::invalid("This data source does not use an SSH tunnel"))?;
+        let session = self.ssh_session(source, ssh, ssh_secret).await?;
+        let (host, port) = tunnel_target(source);
+        drop(Tunnel::open(session.clone(), host, port).await?);
+        Ok(format!("{} reaches {host}:{port}", session.label()))
    }

    /// Connects with `source` as given (not necessarily saved): Test Connection.
@@ -117,6 +117,14 @@ pub(crate) fn oracle_err(e: &oracledb::Error) -> IdeError {
        // config first. Treat it as a logon failure, so the UI prompts for one.
        let kind = match e.kind() {
            oracledb::ErrorKind::NoCredentials => ErrorKind::PermissionDenied,
+            // The thin driver speaks the protocol of Oracle Database 12c and later only.
+            oracledb::ErrorKind::ServerVersionNotSupported => {
+                return IdeError::new(
+                    ErrorKind::Unavailable,
+                    "This Oracle Database is older than 12c. OpenIDEA connects to Oracle Database 12c and later; \
+                     11g and earlier are not supported.",
+                );
+            }
            _ => ErrorKind::InvalidInput,
        };
        return IdeError::new(kind, e.to_string());
@@ -571,6 +579,33 @@ mod tests {
        assert_eq!(connect_string_with(&s("PROD=MYDB"), false).unwrap(), "PROD=MYDB");
    }

+    #[test]
+    fn a_server_older_than_12c_is_named() {
+        use std::io::{Read, Write};
+        let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+        let port = listener.local_addr().unwrap().port();
+        let server = std::thread::spawn(move || {
+            let (mut socket, _) = listener.accept().unwrap();
+            let mut connect = [0u8; 1024];
+            let _ = socket.read(&mut connect);
+            // A TNS ACCEPT packet with protocol version 314, as Oracle Database 11g answers.
+            let mut accept = vec![0u8; 32];
+            accept[1] = 32;
+            accept[4] = 2;
+            accept[8..10].copy_from_slice(&314u16.to_be_bytes());
+            let _ = socket.write_all(&accept);
+        });
+        let config = oracledb::Config::default()
+            .set_credentials("scott", "tiger")
+            .set_connect_string(&format!("//127.0.0.1:{port}/ORCL"))
+            .unwrap()
+            .set_transport_connect_timeout(Some(std::time::Duration::from_secs(5)));
+        let err = oracle_err(&oracledb::connect(config).err().expect("an 11g server is refused"));
+        assert_eq!(err.kind, ErrorKind::Unavailable, "{err:?}");
+        assert!(err.message.contains("older than 12c"), "{}", err.message);
+        server.join().unwrap();
+    }
+
    #[test]
    fn a_tns_alias_resolves_when_tnsnames_exists() {
        let alias = DataSource {
@@ -0,0 +1,96 @@
+//! Data Source › SSH/SSL › Test SSH Tunnel against an in-process SSH server: the SSH login and
+//! the SSH host reaching the database host and port, with no database login.
+
+use ide_core::error::ErrorKind;
+use ide_db::{DataSource, DbDriver, DbManager, DbSsh, DbSshAuth};
+use ide_ssh::{SshFiles, SshManager};
+use std::sync::Arc;
+use tokio::net::TcpListener;
+
+struct Env {
+    _tmp: tempfile::TempDir,
+    db: DbManager,
+    ssh_port: u16,
+}
+
+async fn env() -> Env {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = tmp.path().to_path_buf();
+    let ssh_port = ide_ssh::testing::sshd(root.join("server"), Arc::new(|cmd| panic!("unexpected exec: {cmd}"))).await;
+    let ssh = Arc::new(SshManager::with_files(
+        root.join("ssh-secrets.json"),
+        SshFiles { known_hosts: root.join("known_hosts"), config: None },
+    ));
+    let db = DbManager::new(root.clone(), root.join("passwords.json"), root.join("history.json"), ssh);
+    Env { _tmp: tmp, db, ssh_port }
+}
+
+impl Env {
+    /// A PostgreSQL source on `127.0.0.1:<db_port>` through the test server as `dev`.
+    fn source(&self, db_port: u16) -> DataSource {
+        DataSource {
+            id: "pg".into(),
+            name: "pg".into(),
+            driver: DbDriver::Postgres,
+            host: "127.0.0.1".into(),
+            port: Some(db_port),
+            user: "app".into(),
+            ssh: Some(DbSsh {
+                enabled: true,
+                host: "127.0.0.1".into(),
+                port: Some(self.ssh_port),
+                user: "dev".into(),
+                auth: DbSshAuth::Password,
+                ..Default::default()
+            }),
+            ..Default::default()
+        }
+    }
+}
+
+/// A port something listens on (and never speaks a database protocol).
+async fn listening() -> (TcpListener, u16) {
+    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
+    let port = listener.local_addr().unwrap().port();
+    (listener, port)
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn the_tunnel_is_tested_without_a_database_login() {
+    let env = env().await;
+    let (_db, db_port) = listening().await;
+    let source = env.source(db_port);
+
+    // First contact: the host key has to be trusted, as with Test Connection.
+    let unknown = env.db.test_tunnel(&source, Some("secret".into())).await.unwrap_err();
+    assert!(unknown.message.starts_with("Unknown SSH host key"), "{unknown:?}");
+    env.db.trust_ssh_host("pg").await.unwrap();
+
+    let ok = env.db.test_tunnel(&source, Some("secret".into())).await.unwrap();
+    assert_eq!(ok, format!("[email protected]:{} reaches 127.0.0.1:{db_port}", env.ssh_port));
+
+    let wrong = env.db.test_tunnel(&source, Some("nope".into())).await.unwrap_err();
+    assert!(wrong.message.contains("SSH authentication failed"), "{}", wrong.message);
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn a_database_port_the_ssh_host_cannot_reach_is_named() {
+    let env = env().await;
+    let (listener, closed) = listening().await;
+    drop(listener);
+    let source = env.source(closed);
+    let _ = env.db.test_tunnel(&source, Some("secret".into())).await;
+    env.db.trust_ssh_host("pg").await.unwrap();
+
+    let err = env.db.test_tunnel(&source, Some("secret".into())).await.unwrap_err();
+    assert!(err.message.contains(&format!("cannot reach 127.0.0.1:{closed}")), "{}", err.message);
+}
+
+#[tokio::test]
+async fn a_source_without_a_tunnel_has_nothing_to_test() {
+    let env = env().await;
+    let mut source = env.source(5432);
+    source.ssh.as_mut().unwrap().enabled = false;
+    let err = env.db.test_tunnel(&source, None).await.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::InvalidInput, "{err:?}");
+}
@@ -542,6 +542,24 @@ pub fn compose_config(ep: &DockerEndpoint, dir: &Path, files: &[String]) -> IdeR
    if out.success { Ok(out.stdout) } else { Err(failure(&args, &out.stderr, &out.stdout)) }
 }

+/// Runs the docker CLI with `args` in `dir` and returns its standard output; a non-zero
+/// exit is an error with docker's message.
+pub fn cli(
+    ep: &DockerEndpoint,
+    dir: Option<&Path>,
+    args: &[String],
+    timeout: Duration,
+    cancel: Option<&CancellationToken>,
+) -> IdeResult<String> {
+    let args: Vec<&str> = args.iter().map(String::as_str).collect();
+    let mut cmd = command(ep, &args)?;
+    if let Some(dir) = dir {
+        cmd.current_dir(dir);
+    }
+    let out = process::run(cmd, timeout, cancel)?;
+    if out.success { Ok(out.stdout) } else { Err(failure(&args, &out.stderr, &out.stdout)) }
+}
+
 #[cfg(test)]
 mod local_tests {
    use super::*;
@@ -66,6 +66,7 @@ pub struct Host {
    pub mcp_requests: mcp::Requests,
    /// Commands agents run in the Run tool window (`run_command`).
    pub mcp_agent_runs: mcp::AgentRuns,
+    pub(crate) agent_catalogs: Arc<ide_agent::AgentCatalogs>,
    pub trust: trust::TrustStore,
    pub(crate) mcp_approvals: Arc<trust::McpServerApprovals>,
    pub config_dir: PathBuf,
@@ -152,6 +153,7 @@ impl Host {
            mcp_reports: Default::default(),
            mcp_requests: Default::default(),
            mcp_agent_runs: Default::default(),
+            agent_catalogs: Arc::default(),
            trust: trust::TrustStore::load(&config_dir, &data_dir),
            mcp_approvals: Arc::new(trust::McpServerApprovals::load(&data_dir)),
            proxy_password: ide_ssh::secrets::SecretFile::new(data_dir.join("proxy-password.json")),
@@ -7,8 +7,8 @@ use crate::rpc::Dispatcher;
 use ide_agent::registry::{AgentRegistry, RegistryPaths};
 use ide_agent::{
    AcpImportOutcome, AgentAcceptOutcome, AgentChange, AgentChanges, AgentChangesView, AgentCommand, AgentEntry,
-    AgentEvent, AgentProbe, AgentPrompt, AgentProvider, AgentQueued, AgentTask, CustomAgentInput, ExternalSession,
-    McpScope, McpServer, McpServerInput, NewAgentTask,
+    AgentEvent, AgentModelCatalog, AgentProbe, AgentPrompt, AgentProvider, AgentQueued, AgentTask, CustomAgentInput,
+    ExternalSession, McpScope, McpServer, McpServerInput, NewAgentTask,
 };
 use ide_core::error::ErrorKind;
 use ide_core::{IdeError, IdeEvent, IdeResult, IpcPath, RequestId, SharedSink, TaskId};
@@ -28,6 +28,12 @@ pub fn providers(host: &Host, window: &str) -> IdeResult<Vec<AgentProvider>> {
    Ok(providers)
 }

+/// Refreshes the selected agent's model catalog without sending a prompt.
+pub fn refresh_models(host: &Host, window: &str, provider: String, force: bool) -> IdeResult<AgentModelCatalog> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.refresh_models(&provider, force)
+}
+
 /// Overrides built-in agent `id`'s command with `command` (its agent file keeps the
 /// built-in's driver and arguments), or returns it to auto-detection with `None`.
 pub fn set_command(host: &Host, window: &str, id: String, command: Option<String>) -> IdeResult<()> {
@@ -557,6 +563,9 @@ pub fn mcp_import(host: &Host, window: &str) -> IdeResult<Vec<McpServer>> {
 pub(crate) fn register(d: &mut Dispatcher) {
    d.add("agent_subscribe", |c| async move { subscribe(&c.host, &c.window, c.channel("onEvent")?) });
    d.add("agent_providers", |c| async move { providers(&c.host, &c.window) });
+    d.add("agent_refresh_models", |c| async move {
+        refresh_models(&c.host, &c.window, c.arg("provider")?, c.arg("force")?)
+    });
    d.add("agent_set_command", |c| async move { set_command(&c.host, &c.window, c.arg("id")?, c.arg("command")?) });
    d.add("agent_set_env", |c| async move { set_env(&c.host, &c.window, c.arg("id")?, c.arg("env")?) });
    d.add("agent_registry_list", |c| async move { registry_list(&c.host, &c.window, c.arg("request")?).await });
@@ -12,6 +12,7 @@ use ide_db::{
 };
 use serde::{Deserialize, Serialize};
 use specta::Type;
+use std::path::PathBuf;

 /// One statement of a console run.
 #[derive(Clone, Serialize, Deserialize, Type)]
@@ -42,6 +43,10 @@ pub(crate) fn register(d: &mut Dispatcher) {
        );
        test(&c.host, &c.window, source, password, ssh_secret).await
    });
+    d.add("db_test_tunnel", |c| async move {
+        let (source, ssh_secret) = (c.arg::<DataSource>("source")?, c.arg::<Option<String>>("sshSecret")?);
+        test_tunnel(&c.host, &c.window, source, ssh_secret).await
+    });
    d.add("db_set_ssh_secret", |c| async move {
        let (id, secret, save) = (c.arg::<String>("id")?, c.arg::<Option<String>>("secret")?, c.arg::<bool>("save")?);
        set_ssh_secret(&c.host, &c.window, &id, secret, save).await
@@ -175,6 +180,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
        apply_edits(&c.host, &c.window, &id, &schema, &table, edits).await
    });
    d.add("db_console_path", |c| async move { console_path(&c.host, &c.arg::<String>("id")?) });
+    d.add("db_consoles", |c| async move { consoles(&c.host, &c.arg::<String>("id")?, c.arg("create")?) });
 }

 /// The data sources configured for the project (the tree's roots).
@@ -212,6 +218,17 @@ pub async fn test(
    db.test(&source, password, ssh_secret).await
 }

+/// Checks the SSH tunnel of `source` alone: SSH login and the SSH host reaching the database.
+pub async fn test_tunnel(
+    host: &Host,
+    window: &str,
+    source: DataSource,
+    ssh_secret: Option<String>,
+) -> IdeResult<String> {
+    let db = host.project(window)?.db.clone();
+    db.test_tunnel(&source, ssh_secret).await
+}
+
 /// Remembers the SSH password / key passphrase of a data source (see `set_password`).
 pub async fn set_ssh_secret(host: &Host, window: &str, id: &str, secret: Option<String>, save: bool) -> IdeResult<()> {
    let db = host.project(window)?.db.clone();
@@ -457,11 +474,52 @@ pub async fn apply_edits(
 /// created on first use. Consoles are files of the project, so a remote
 /// window resolves it on the host the project runs on.
 pub fn console_path(host: &Host, id: &str) -> IdeResult<IpcPath> {
+    let file = console_dir(host, id)?.join("console.sql");
+    if !file.exists() {
+        std::fs::write(&file, "")?;
+    }
+    Ok(file.into())
+}
+
+/// The query consoles of data source `id`: the default `console.sql`, then
+/// `console_1.sql`, `console_2.sql`… in order. `create` adds the next one first
+/// (DataGrip's New › Query Console).
+pub fn consoles(host: &Host, id: &str, create: bool) -> IdeResult<Vec<IpcPath>> {
+    let dir = console_dir(host, id)?;
+    let default = dir.join("console.sql");
+    let mut numbered: Vec<(u32, PathBuf)> = std::fs::read_dir(&dir)?
+        .filter_map(|e| {
+            let path = e.ok()?.path();
+            let n = path.file_name()?.to_str()?.strip_prefix("console_")?.strip_suffix(".sql")?.parse().ok()?;
+            Some((n, path))
+        })
+        .collect();
+    numbered.sort();
+    if create {
+        // The default console comes first; once it exists, the next number.
+        if !default.exists() {
+            std::fs::write(&default, "")?;
+        } else {
+            let n = numbered.last().map_or(1, |(n, _)| n + 1);
+            let file = dir.join(format!("console_{n}.sql"));
+            std::fs::write(&file, "")?;
+            numbered.push((n, file));
+        }
+    }
+    let mut out: Vec<IpcPath> = Vec::new();
+    if default.exists() {
+        out.push(default.into());
+    }
+    out.extend(numbered.into_iter().map(|(_, p)| p.into()));
+    Ok(out)
+}
+
+/// `<dataDir>/consoles/db/<id>`: `<id>` for the default database, `<id>.<database>` for the others.
+fn console_dir(host: &Host, id: &str) -> IdeResult<PathBuf> {
    let (source, database) = ide_db::split_target(id);
    if source.is_empty() || !source.chars().all(|c| c.is_ascii_alphanumeric() || c == '-' || c == '_') {
        return Err(IdeError::invalid("invalid data source id"));
    }
-    // One console per database: `<id>` for the default one, `<id>.<database>` for the others.
    let name = match database {
        Some(db) => {
            let safe: String =
@@ -472,9 +530,5 @@ pub fn console_path(host: &Host, id: &str) -> IdeResult<IpcPath> {
    };
    let dir = host.data_dir.join("consoles").join("db").join(&name);
    std::fs::create_dir_all(&dir)?;
-    let file = dir.join("console.sql");
-    if !file.exists() {
-        std::fs::write(&file, "")?;
-    }
-    Ok(file.into())
+    Ok(dir)
 }
@@ -372,6 +372,46 @@ pub async fn debug_restart_frame(host: &Host, _window: &str, session: DebugSessi
    host.debugger.restart_frame(session, frame_id).await
 }

+pub async fn debug_js_custom_breakpoints(
+    host: &Host,
+    _window: &str,
+    session: DebugSessionId,
+    ids: Vec<String>,
+    xhr: Vec<String>,
+) -> IdeResult<()> {
+    host.debugger.js_set_custom_breakpoints(session, ids, xhr).await
+}
+
+pub async fn debug_js_response_overrides(
+    host: &Host,
+    _window: &str,
+    session: DebugSessionId,
+    rules: Vec<ide_dap::JsResponseRule>,
+) -> IdeResult<()> {
+    host.debugger.js_set_response_overrides(session, rules).await
+}
+
+pub async fn debug_js_response_body(
+    host: &Host,
+    _window: &str,
+    session: DebugSessionId,
+    request_id: String,
+) -> IdeResult<ide_dap::JsResponseBody> {
+    host.debugger.js_response_body(session, request_id).await
+}
+
+pub async fn debug_js_start_profile(host: &Host, _window: &str, session: DebugSessionId) -> IdeResult<()> {
+    host.debugger.js_start_profile(session).await
+}
+
+pub async fn debug_js_stop_profile(
+    host: &Host,
+    _window: &str,
+    session: DebugSessionId,
+) -> IdeResult<ide_core::IpcPath> {
+    host.debugger.js_stop_profile(session).await.map(Into::into)
+}
+
 pub fn debug_capabilities(host: &Host, _window: &str, session: DebugSessionId) -> IdeResult<DebugCapabilities> {
    host.debugger.capabilities(session)
 }
@@ -588,6 +628,23 @@ pub(crate) fn register(d: &mut Dispatcher) {
        debug_restart_frame(&c.host, &c.window, c.arg("session")?, c.arg("frameId")?).await
    });
    d.add("debug_capabilities", |c| async move { debug_capabilities(&c.host, &c.window, c.arg("session")?) });
+    d.add("debug_js_response_overrides", |c| async move {
+        debug_js_response_overrides(&c.host, &c.window, c.arg("session")?, c.arg("rules")?).await
+    });
+    d.add("debug_js_response_body", |c| async move {
+        debug_js_response_body(&c.host, &c.window, c.arg("session")?, c.arg("requestId")?).await
+    });
+    d.add("debug_js_custom_breakpoints", |c| async move {
+        debug_js_custom_breakpoints(&c.host, &c.window, c.arg("session")?, c.arg("ids")?, c.arg("xhr")?).await
+    });
+    d.add(
+        "debug_js_start_profile",
+        |c| async move { debug_js_start_profile(&c.host, &c.window, c.arg("session")?).await },
+    );
+    d.add(
+        "debug_js_stop_profile",
+        |c| async move { debug_js_stop_profile(&c.host, &c.window, c.arg("session")?).await },
+    );
    d.add("debug_set_function_breakpoints", |c| async move {
        debug_set_function_breakpoints(&c.host, &c.window, c.arg("breakpoints")?).await
    });
@@ -21,6 +21,28 @@ pub fn close(host: &Host, window: &str, doc: DocId) -> IdeResult<()> {
    Ok(())
 }

+/// Opens an editable untitled buffer (a new-file tab); it reaches the disk
+/// through [`save_as`], which turns it into a regular file document. `name`
+/// re-references an already minted buffer instead of creating one.
+pub async fn open_untitled(host: &Host, window: &str, name: Option<String>) -> IdeResult<DocumentInfo> {
+    let project = host.project(window)?;
+    host.blocking(move || project.documents.open_untitled(name.as_deref())).await
+}
+
+/// Save As for an untitled buffer ([`Documents::save_as`]); LightEdit windows
+/// start watching the saved file's folder.
+pub async fn save_as(host: &Host, window: &str, doc: DocId, path: PathBuf) -> IdeResult<DocumentInfo> {
+    let project = host.project(window)?;
+    host.blocking(move || {
+        let info = project.documents.save_as(doc, &path)?;
+        if let Some(dir) = path.parent().filter(|_| project.light) {
+            project.watch_light_dir(dir);
+        }
+        Ok(info)
+    })
+    .await
+}
+
 /// Applies a CodeMirror change set; returns the new version (`outOfSync` when `base_version` is stale).
 pub fn edit(host: &Host, window: &str, doc: DocId, base_version: u32, changes: ChangeSet) -> IdeResult<u32> {
    host.project(window)?.documents.edit(doc, base_version, changes)
@@ -50,7 +50,10 @@ pub async fn doc_set_encoding(
    reload: bool,
 ) -> IdeResult<DocumentEncoding> {
    let project = host.project(window)?;
-    if reload && let Some(uri) = project.documents.virtual_uri(doc)? {
+    if reload
+        && !project.documents.is_untitled(doc)?
+        && let Some(uri) = project.documents.virtual_uri(doc)?
+    {
        let vd = if uri.starts_with("git-revision:") {
            crate::ops::vcs::revision_virtual_document(host, window, &uri, Some(&encoding)).await?
        } else {
@@ -159,6 +162,15 @@ pub async fn doc_highlights(host: &Host, window: &str, doc: DocId) -> IdeResult<
    .await
 }

+/// Python class facts the inheritance inspections read: base names as written, a method's
+/// parameters, decorator semantics and its body shape. Tree-sitter answers; no LSP.
+pub async fn doc_python_facts(host: &Host, window: &str, doc: DocId) -> IdeResult<ide_language::PythonFacts> {
+    let project = host.project(window)?;
+    let syntax = host.syntax();
+    let snap = project.documents.text_snapshot(doc)?;
+    blocking(move || Ok(syntax.python_facts(&snap.language, &snap.text))).await
+}
+
 /// Extend Selection (⌥↑): syntax ranges around `offset`, innermost first.
 /// Large documents fall back to word / line / document ranges.
 pub async fn doc_selection_ranges(host: &Host, window: &str, doc: DocId, offset: u32) -> IdeResult<Vec<Range>> {
@@ -208,6 +220,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("doc_outline", |c| async move { doc_outline(&c.host, &c.window, c.arg("doc")?).await });
    d.add("doc_folding", |c| async move { doc_folding(&c.host, &c.window, c.arg("doc")?).await });
    d.add("doc_highlights", |c| async move { doc_highlights(&c.host, &c.window, c.arg("doc")?).await });
+    d.add("doc_python_facts", |c| async move { doc_python_facts(&c.host, &c.window, c.arg("doc")?).await });
    d.add("doc_selection_ranges", |c| async move {
        doc_selection_ranges(&c.host, &c.window, c.arg("doc")?, c.arg("offset")?).await
    });
@@ -74,9 +74,15 @@ pub async fn lsp_completion(
    host.end_request(request);
    // Plugin providers (`[[contributes.providers]]`) add theirs.
    let Some((plugins, d)) = plugin_providers(host, window, doc, ProviderKind::Completion) else { return result };
-    let items = plugin_call(move || plugins.provide_completion(&d, pos, trigger.as_deref())).await.unwrap_or_default();
+    let (covered, items) = plugin_call(move || plugins.provide_completion_for_editor(&d, pos, trigger.as_deref()))
+        .await
+        .unwrap_or_default();
    if items.is_empty() {
-        return Ok(result.unwrap_or(CompletionList { is_incomplete: true, items: Vec::new() }));
+        return if covered {
+            Ok(result.unwrap_or(CompletionList { is_incomplete: true, items: Vec::new() }))
+        } else {
+            result
+        };
    }
    let mut list = result.unwrap_or(CompletionList { is_incomplete: false, items: Vec::new() });
    list.items.extend(items.into_iter().map(|(_, item)| plugin_completion(item)));
@@ -1466,6 +1472,15 @@ pub async fn lsp_type_hierarchy(
    host.project(window)?.lsp.type_hierarchy(doc, pos, direction).await
 }

+pub async fn lsp_prepare_type_hierarchy(
+    host: &Host,
+    window: &str,
+    doc: DocId,
+    pos: Pos,
+) -> IdeResult<Option<HierarchyItem>> {
+    host.project(window)?.lsp.prepare_type_hierarchy(doc, pos).await
+}
+
 pub fn lsp_servers(host: &Host, window: &str) -> IdeResult<Vec<ServerInfo>> {
    Ok(host.project(window)?.lsp.servers())
 }
@@ -1850,6 +1865,9 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("lsp_type_hierarchy", |c| async move {
        lsp_type_hierarchy(&c.host, &c.window, c.arg("doc")?, c.arg("pos")?, c.arg("direction")?).await
    });
+    d.add("lsp_prepare_type_hierarchy", |c| async move {
+        lsp_prepare_type_hierarchy(&c.host, &c.window, c.arg("doc")?, c.arg("pos")?).await
+    });
    d.add("lsp_servers", |c| async move { lsp_servers(&c.host, &c.window) });
    d.add("lsp_resend_diagnostics", |c| async move { lsp_resend_diagnostics(&c.host, &c.window) });
    d.add("lsp_restart", |c| async move { lsp_restart(&c.host, &c.window, c.arg("server")?).await });
@@ -31,6 +31,7 @@ pub mod scaffold;
 pub mod sdk;
 pub mod search;
 pub mod spell;
+mod ssh;
 pub mod syntax;
 pub mod term;
 pub mod tools;
@@ -95,6 +96,7 @@ pub fn register_all(d: &mut crate::rpc::Dispatcher) {
    deploy::register(d);
    docker::register(d);
    db::register(d);
+    ssh::register(d);
 }

 impl Host {
@@ -2,7 +2,7 @@ use super::doc::blocking;
 use crate::Host;
 use crate::Project;
 use crate::rpc::Dispatcher;
-use ide_core::{DocId, IdeResult, IpcPath, Location, Pos};
+use ide_core::{DocId, IdeResult, IpcPath, LanguageId, Location, Pos};
 use ide_index::{ExtensionCount, FileMatch, IndexStatus, SymbolFilter, SymbolMatch};
 use ide_language::{FileReference, WebReference};
 use ide_workspace::file_refs::{self, PathCompletion};
@@ -22,6 +22,23 @@ pub struct WebGoto {

 const MAX_WEB_TARGETS: usize = 200;

+/// A Python class definition and the base names written in its source. The UI builds a
+/// name → locations index from every class in the project (attached dependency roots
+/// included) to compute ↑ overrides / ↓ overridden gutter markers without a language
+/// server's type-hierarchy provider.
+#[derive(Clone, Debug, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct ClassInheritance {
+    /// Start of the class definition's selection range (0-based line, UTF-16 column).
+    pub path: IpcPath,
+    pub line: u32,
+    pub col: u32,
+    pub name: String,
+    /// Base names as written in source (bare name, e.g. `AllToAllTokenDispatcher`; a
+    /// qualified name keeps only its last segment).
+    pub bases: Vec<String>,
+}
+
 /// The project root and its resource roots (served at `/`), for file references.
 fn reference_roots(project: &Project) -> (PathBuf, Vec<PathBuf>) {
    let resources = project.roots().resource_dirs().iter().map(|d| project.root.join(d)).collect();
@@ -174,6 +191,74 @@ pub async fn nav_index_definitions(
    .await
 }

+/// Every Python class in the project (attached dependency roots included) and its base
+/// names. The index covers content roots, so this is the whole-project answer the UI uses
+/// for inheritance gutter markers when no type-hierarchy provider exists.
+pub async fn nav_inheritance(host: &Host, window: &str) -> IdeResult<Vec<ClassInheritance>> {
+    let project = host.project(window)?;
+    let syntax = host.syntax();
+    blocking(move || {
+        let python = LanguageId::new("python");
+        let files = project.index.files_with_extensions(&["py".into(), "pyi".into()], 20_000);
+        let mut cache = CLASS_BASES.lock();
+        let mut out = Vec::new();
+        for path in files {
+            // The open (possibly unsaved) buffer is keyed by its text, a file on disk by its
+            // size and modification time, so only changed files are parsed again.
+            let open = project.documents.text_of(&path);
+            let stamp = match &open {
+                Some(text) => Stamp::Text(text_hash(text)),
+                None => match std::fs::metadata(&path) {
+                    Ok(m) => Stamp::Disk(m.len(), m.modified().ok()),
+                    Err(_) => continue,
+                },
+            };
+            let classes = match cache.get(&path) {
+                Some((cached, classes)) if *cached == stamp => classes,
+                _ => {
+                    let text = match open {
+                        Some(text) => text,
+                        None => match project.text_of(&path) {
+                            Ok(text) => text,
+                            Err(_) => continue,
+                        },
+                    };
+                    let classes = syntax.class_bases(&python, &text);
+                    &cache.entry(path.clone()).insert_entry((stamp, classes)).into_mut().1
+                }
+            };
+            out.extend(classes.iter().map(|class| ClassInheritance {
+                path: IpcPath::from(path.clone()),
+                line: class.line,
+                col: class.col,
+                name: class.name.clone(),
+                bases: class.bases.clone(),
+            }));
+        }
+        Ok(out)
+    })
+    .await
+}
+
+#[derive(Clone, PartialEq, Eq)]
+enum Stamp {
+    Text(u64),
+    Disk(u64, Option<std::time::SystemTime>),
+}
+
+fn text_hash(text: &str) -> u64 {
+    use std::hash::{Hash, Hasher};
+    let mut h = std::collections::hash_map::DefaultHasher::new();
+    text.hash(&mut h);
+    h.finish()
+}
+
+type ClassBasesCache = std::collections::HashMap<PathBuf, (Stamp, Vec<ide_language::ClassBases>)>;
+
+/// Class bases per Python file, reused while the file is unchanged.
+static CLASS_BASES: std::sync::LazyLock<parking_lot::Mutex<ClassBasesCache>> =
+    std::sync::LazyLock::new(Default::default);
+
 /// The existing file or directory a path written in `from` names (`href`, `url()`, a string literal).
 pub async fn fs_resolve_reference(
    host: &Host,
@@ -249,6 +334,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("nav_index_definitions", |c| async move {
        nav_index_definitions(&c.host, &c.window, c.arg("name")?, c.arg("from")?).await
    });
+    d.add("nav_inheritance", |c| async move { nav_inheritance(&c.host, &c.window).await });
    d.add("fs_resolve_reference", |c| async move {
        fs_resolve_reference(&c.host, &c.window, c.arg("from")?, c.arg("value")?).await
    });
@@ -239,6 +239,12 @@ pub fn set_settings(
    let toolchain = ["languages", "tools", "languageServers", "projectStructure"]
        .iter()
        .any(|k| key == *k || key.starts_with(&format!("{k}.")));
+    // A run target chosen as the Python interpreter (or changed) needs a snapshot of its libraries.
+    if ["languages", "languages.python", "languages.python.interpreter", "runTargets"].contains(&key) {
+        for project in affected() {
+            crate::ops::sdk::container_python::ensure(host, &project);
+        }
+    }
    // Code style only reaches servers as settings (e.g. jdtls' formatter profile); builds don't depend on it.
    if code_style || toolchain {
        for project in affected() {
@@ -508,7 +508,7 @@ pub fn list(host: &Host) -> Vec<RunInfo> {
 }

 mod commands;
-mod container;
+pub(crate) mod container;
 pub use commands::*;

 #[cfg(test)]
@@ -33,23 +33,11 @@ pub(super) async fn prepare(host: &Host, root: &Path, target: RunTarget, config:
    let root = root.to_path_buf();
    let data_dir = host.data_dir.clone();
    host.blocking(move || {
-        if !ide_docker::endpoint_is_local(&endpoint)? {
-            return Err(IdeError::invalid(format!(
-                "Run target '{}' uses a Docker daemon on another machine: the project can only be mounted from a local one",
-                target.name
-            )));
-        }
+        require_local(&endpoint, &target)?;
        let docker = ide_docker::docker_executable().ok_or_else(|| {
            IdeError::unavailable("docker executable not found; install Docker and make sure it is on PATH")
        })?;
-        let container_root = match target.container_root.trim() {
-            "" if target.kind == RunTargetKind::Compose => {
-                let json = ide_docker::compose_config(&endpoint, &root, &target.compose_files)?;
-                compose_container_root(&json, target.service.trim(), &root)?
-            }
-            "" => default_container_root(&root),
-            folder => folder.to_owned(),
-        };
+        let container_root = container_root(&endpoint, &root, &target)?;
        let file_env = env_files(&root, &config)?;
        let name = container_name(&config.id, &unique());
        let debugging = if debug { Some(Debugging::prepare(&data_dir)?) } else { None };
@@ -75,6 +63,29 @@ pub(super) async fn prepare(host: &Host, root: &Path, target: RunTarget, config:
    .await
 }

+/// The project can only be bind-mounted from a daemon on this machine.
+pub(crate) fn require_local(endpoint: &DockerEndpoint, target: &RunTarget) -> IdeResult<()> {
+    if !ide_docker::endpoint_is_local(endpoint)? {
+        return Err(IdeError::invalid(format!(
+            "Run target '{}' uses a Docker daemon on another machine: the project can only be mounted from a local one",
+            target.name
+        )));
+    }
+    Ok(())
+}
+
+/// Where the project is in the target's containers.
+pub(crate) fn container_root(endpoint: &DockerEndpoint, root: &Path, target: &RunTarget) -> IdeResult<String> {
+    Ok(match target.container_root.trim() {
+        "" if target.kind == RunTargetKind::Compose => {
+            let json = ide_docker::compose_config(endpoint, root, &target.compose_files)?;
+            compose_container_root(&json, target.service.trim(), root)?
+        }
+        "" => default_container_root(root),
+        folder => folder.to_owned(),
+    })
+}
+
 /// What a debug run mounts and publishes.
 struct Debugging {
    port: u16,
@@ -104,7 +115,7 @@ fn free_port() -> IdeResult<u16> {
 }

 /// The target's Docker connection (Services tool window), by id; none = the CLI's daemon.
-fn endpoint(data_dir: &Path, target: &RunTarget) -> IdeResult<DockerEndpoint> {
+pub(crate) fn endpoint(data_dir: &Path, target: &RunTarget) -> IdeResult<DockerEndpoint> {
    let id = target.docker_connection.trim();
    if id.is_empty() {
        return Ok(DockerEndpoint::Default);
@@ -10,6 +10,9 @@ use std::path::PathBuf;
 use std::sync::Mutex;
 use std::sync::atomic::{AtomicUsize, Ordering};

+pub(crate) mod container_python;
+pub use container_python::{ContainerPython, sdk_container_python, sdk_container_python_refresh};
+
 fn join_err(e: impl std::fmt::Display) -> IdeError {
    IdeError::internal(e.to_string())
 }
@@ -232,12 +235,17 @@ pub async fn sdk_project_libraries(
    let project = host.project(window)?;
    let (root, cache, settings) = (project.root.clone(), project.build_cache_dir(), project.settings.effective());
    let cancel = host.begin_project_request(window, request);
+    let container = container_python::library_group(host, &root, &settings);
    let libraries = {
        let (root, settings, cancel, on_groups) = (root.clone(), settings.clone(), cancel.clone(), on_groups.clone());
        tokio::task::spawn_blocking(move || {
-            ide_sdk::libraries::project_libraries_stream(&root, &settings, &[], &cancel, &|groups| {
+            if let Some(group) = &container {
+                let _ = on_groups.send(vec![group.clone()]);
+            }
+            let groups = ide_sdk::libraries::project_libraries_stream(&root, &settings, &[], &cancel, &|groups| {
                let _ = on_groups.send(groups);
-            })
+            });
+            container.into_iter().chain(groups).collect::<Vec<_>>()
        })
    };
    let dependencies = {
@@ -377,6 +385,8 @@ pub(crate) fn register(d: &mut Dispatcher) {
    );
    d.add("sdk_python_effective", |c| async move { sdk_python_effective(&c.host, &c.window, c.arg("near")?) });
    d.add("sdk_php_effective", |c| async move { sdk_php_effective(&c.host, &c.window) });
+    d.add("sdk_container_python", |c| async move { sdk_container_python(&c.host, &c.window) });
+    d.add("sdk_container_python_refresh", |c| async move { sdk_container_python_refresh(&c.host, &c.window).await });
    d.add("sdk_php_xdebug", |c| async move { sdk_php_xdebug(&c.host, &c.window, c.arg("php")?, c.arg("cwd")?).await });
    d.add(
        "sdk_php_language_level",
@@ -0,0 +1,298 @@
+//! A Docker or Compose run target's Python as the project interpreter: snapshots of the
+//! container's library folders for the language server (see `ide_sdk::container_python`).
+//!
+//! A snapshot runs the target's Python once in a new container (the image's entrypoint
+//! and the service's dependencies skipped), then copies its `sys.path` folders out of
+//! the stopped container with `docker cp`. Nothing is installed in the container.
+
+use crate::Host;
+use crate::project::Project;
+use ide_core::event::NotifyLevel;
+use ide_core::remote_settings::{RunTarget, RunTargetKind};
+use ide_core::settings::Settings;
+use ide_core::{IdeError, IdeEvent, IdeResult, IpcPath, TaskId};
+use ide_sdk::container_python::{self as snapshots, Snapshot};
+use ide_sdk::python::PythonPackage;
+use std::collections::HashSet;
+use std::path::{Path, PathBuf};
+use std::sync::{Arc, LazyLock, Mutex};
+use std::time::Duration;
+
+/// Building or pulling the image may come first.
+const PROBE_TIMEOUT: Duration = Duration::from_secs(15 * 60);
+const COPY_TIMEOUT: Duration = Duration::from_secs(10 * 60);
+const QUICK: Duration = Duration::from_secs(30);
+
+/// The project interpreter when it is a run target's.
+#[derive(Clone, Debug, serde::Serialize, specta::Type)]
+#[serde(rename_all = "camelCase")]
+pub struct ContainerPython {
+    /// The run target's id.
+    pub target: String,
+    /// Its name; empty when no run target has the id.
+    pub name: String,
+    /// The Python version of the snapshot in use; `None`: no snapshot yet.
+    pub version: Option<String>,
+    /// The image the snapshot was copied from.
+    pub image: Option<String>,
+    /// The copied library folders on this machine.
+    pub folders: Vec<IpcPath>,
+    /// Packages of the snapshot (read-only).
+    pub packages: Vec<PythonPackage>,
+    /// A snapshot is being taken.
+    pub updating: bool,
+}
+
+/// Where snapshots are kept, and the Docker connections the targets refer to.
+#[derive(Clone)]
+struct Dirs {
+    data: PathBuf,
+    /// `<local data>/container-python/`: `<project>/<target>/<image>/` and `neutral/`.
+    cache: PathBuf,
+}
+
+impl Dirs {
+    fn of(host: &Host) -> Self {
+        Self::new(&host.data_dir, &host.local_data_dir)
+    }
+
+    fn new(data_dir: &Path, local_data_dir: &Path) -> Self {
+        Self { data: data_dir.to_path_buf(), cache: local_data_dir.join("container-python") }
+    }
+
+    fn target(&self, root: &Path, target: &str) -> PathBuf {
+        snapshots::target_dir(&self.cache.join(crate::project::project_key(root)), target)
+    }
+}
+
+/// Target folders with a snapshot being taken.
+static UPDATING: LazyLock<Mutex<HashSet<PathBuf>>> = LazyLock::new(Default::default);
+
+fn updating(dir: &Path) -> bool {
+    UPDATING.lock().unwrap_or_else(|e| e.into_inner()).contains(dir)
+}
+
+/// The snapshot in use for the project's interpreter, if it is a run target's.
+fn current(dirs: &Dirs, root: &Path, settings: &Settings) -> Option<(PathBuf, Snapshot)> {
+    let target = settings.languages.python.run_target()?;
+    snapshots::current(&dirs.target(root, target))
+}
+
+/// Language server configuration: basedpyright / pyright see the container's libraries.
+pub(crate) fn configure_server(
+    cfg: &mut ide_language::LanguageServerConfig,
+    local_data_dir: &Path,
+    root: &Path,
+    settings: &Settings,
+) {
+    if settings.languages.python.run_target().is_none() {
+        return;
+    }
+    let current = current(&Dirs::new(local_data_dir, local_data_dir), root, settings);
+    snapshots::configure_server(cfg, current.as_ref().map(|(d, s)| (d.as_path(), s)));
+}
+
+/// External Libraries: the snapshot's folders, named after the run target.
+pub(crate) fn library_group(host: &Host, root: &Path, settings: &Settings) -> Option<ide_sdk::libraries::LibraryGroup> {
+    let target = settings.languages.python.run_target()?;
+    let (dir, snapshot) = current(&Dirs::of(host), root, settings)?;
+    let name = settings.run_targets.iter().find(|t| t.id == target).map_or(target, |t| t.name.as_str());
+    snapshots::library_group(name, &dir, &snapshot)
+}
+
+/// The project interpreter when it is a run target's, with its snapshot.
+pub fn sdk_container_python(host: &Host, window: &str) -> IdeResult<Option<ContainerPython>> {
+    host.require_trust(window)?;
+    let project = host.project(window)?;
+    Ok(describe(host, &project.root, &project.settings.effective()))
+}
+
+fn describe(host: &Host, root: &Path, settings: &Settings) -> Option<ContainerPython> {
+    let target = settings.languages.python.run_target()?;
+    let name = settings.run_targets.iter().find(|t| t.id == target).map(|t| t.name.clone()).unwrap_or_default();
+    let dir = Dirs::of(host).target(root, target);
+    let mut out = ContainerPython {
+        target: target.to_owned(),
+        name,
+        version: None,
+        image: None,
+        folders: Vec::new(),
+        packages: Vec::new(),
+        updating: updating(&dir),
+    };
+    if let Some((dir, snapshot)) = snapshots::current(&dir) {
+        out.folders = snapshots::local_folders(&dir, &snapshot).into_iter().map(Into::into).collect();
+        out.packages = snapshots::packages(&dir, &snapshot);
+        out.version = Some(snapshot.probe.version);
+        out.image = Some(snapshot.image);
+    }
+    Some(out)
+}
+
+/// Takes a new snapshot of the project interpreter's container (also of an image that
+/// has one already), then the language servers pick it up.
+pub async fn sdk_container_python_refresh(host: &Host, window: &str) -> IdeResult<Option<ContainerPython>> {
+    host.require_trust(window)?;
+    let project = host.project(window)?;
+    update(Dirs::of(host), &project, true).await?;
+    Ok(describe(host, &project.root, &project.settings.effective()))
+}
+
+/// Takes a snapshot when the project interpreter is a run target's and the current image
+/// has none yet (a new choice, a rebuilt image), in the background. Errors are notified.
+pub(crate) fn ensure(host: &Host, project: &Arc<Project>) {
+    if !project.is_trusted() || project.settings.effective().languages.python.run_target().is_none() {
+        return;
+    }
+    let (dirs, project) = (Dirs::of(host), project.clone());
+    host.runtime.spawn(async move {
+        if let Err(e) = update(dirs, &project, false).await
+            && e.kind != ide_core::error::ErrorKind::Cancelled
+        {
+            project.sink.emit(IdeEvent::Notify {
+                level: NotifyLevel::Warning,
+                title: "Cannot copy the container's Python libraries".into(),
+                body: Some(e.message),
+            });
+        }
+    });
+}
+
+async fn update(dirs: Dirs, project: &Arc<Project>, force: bool) -> IdeResult<()> {
+    let settings = project.settings.effective();
+    let Some(id) = settings.languages.python.run_target() else { return Ok(()) };
+    let target = ide_remote::service::run_target(&settings, id)?;
+    if target.kind == RunTargetKind::Ssh {
+        return Err(IdeError::invalid(format!(
+            "Run target '{}' runs over SSH: only a Docker or Compose run target can be the project interpreter",
+            target.name
+        )));
+    }
+    let dir = dirs.target(&project.root, id);
+    if !UPDATING.lock().unwrap_or_else(|e| e.into_inner()).insert(dir.clone()) {
+        return Ok(());
+    }
+    let _done = Updating(dir.clone());
+    let endpoint = crate::ops::run::container::endpoint(&dirs.data, &target)?;
+    let task = TaskId::next();
+    let title = format!("Python libraries of {}", target.name);
+    let (root, sink) = (project.root.clone(), project.sink.clone());
+    let progress = move |message: &str, done: bool| {
+        sink.emit(IdeEvent::Task {
+            id: task,
+            title: title.clone(),
+            message: Some(message.to_owned()),
+            fraction: None,
+            done,
+            cancellable: false,
+        })
+    };
+    let report = progress.clone();
+    let result = tokio::task::spawn_blocking(move || {
+        take(&endpoint, &root, &target, &dir, &dirs.cache, force, &|message| report(message, false))
+    })
+    .await
+    .map_err(|e| IdeError::internal(e.to_string()))
+    .and_then(|r| r);
+    progress(if result.is_ok() { "Done" } else { "Failed" }, true);
+    if result? {
+        project.lsp.reconfigure().await;
+    }
+    Ok(())
+}
+
+struct Updating(PathBuf);
+
+impl Drop for Updating {
+    fn drop(&mut self) {
+        UPDATING.lock().unwrap_or_else(|e| e.into_inner()).remove(&self.0);
+    }
+}
+
+/// Removes the probe container, also when copying failed.
+struct Container<'a> {
+    endpoint: &'a ide_docker::DockerEndpoint,
+    name: String,
+}
+
+impl Drop for Container<'_> {
+    fn drop(&mut self) {
+        let args = ["rm", "--force", "--volumes", &self.name].map(String::from);
+        if let Err(e) = ide_docker::cli(self.endpoint, None, &args, QUICK, None) {
+            tracing::warn!("cannot remove container {}: {}", self.name, e.message);
+        }
+    }
+}
+
+/// Takes the snapshot in `target_dir` and makes it the one in use; `false` when the image
+/// had one already and it is in use (unless `force`).
+fn take(
+    endpoint: &ide_docker::DockerEndpoint,
+    root: &Path,
+    target: &RunTarget,
+    target_dir: &Path,
+    cache: &Path,
+    force: bool,
+    progress: &dyn Fn(&str),
+) -> IdeResult<bool> {
+    crate::ops::run::container::require_local(endpoint, target)?;
+    let container_root = crate::ops::run::container::container_root(endpoint, root, target)?;
+    let name = format!("openidea-python-{}", unique());
+    let args = ide_remote::docker::python_probe_args(target, root, &name, snapshots::PROBE)?;
+    progress("Starting the container's Python");
+    let container = Container { endpoint, name };
+    let out = ide_docker::cli(endpoint, Some(root), &args, PROBE_TIMEOUT, None);
+    let probe = snapshots::parse_probe(&out?)?;
+    let inspect = ["inspect".into(), "--format".into(), "{{.Image}}".into(), container.name.clone()];
+    let image = ide_docker::cli(endpoint, None, &inspect, QUICK, None)?.trim().to_owned();
+    if image.is_empty() {
+        return Err(IdeError::internal(format!("docker inspect printed no image for {}", container.name)));
+    }
+    let dir = target_dir.join(snapshots::dir_name(&image));
+    let before = snapshots::current(target_dir).map(|(_, s)| s.image);
+    if !force && snapshots::read(&dir).is_some() {
+        snapshots::make_current(target_dir, &image)?;
+        return Ok(before.as_deref() != Some(image.as_str()));
+    }
+    let partial = target_dir.join(format!("{}.partial", snapshots::dir_name(&image)));
+    if partial.exists() {
+        std::fs::remove_dir_all(&partial)?;
+    }
+    std::fs::create_dir_all(&partial)?;
+    let mut folders = Vec::new();
+    for folder in snapshots::folders_to_copy(&probe, &container_root) {
+        progress(&format!("Copying {folder}"));
+        let local = snapshots::local_folder(&partial, &folder);
+        let Some(parent) = local.parent() else { continue };
+        std::fs::create_dir_all(parent)?;
+        // Into an existing folder: `docker cp` puts the source folder in it under its own name.
+        let args = ["cp".into(), format!("{}:{folder}", container.name), format!("{}/", parent.to_string_lossy())];
+        match ide_docker::cli(endpoint, None, &args, COPY_TIMEOUT, None) {
+            Ok(_) => folders.push(folder),
+            Err(e) => tracing::warn!("cannot copy {folder} from {}: {}", container.name, e.message),
+        }
+    }
+    drop(container);
+    progress("Preparing the language server's interpreter");
+    let snapshot = Snapshot {
+        neutral_python: snapshots::neutral_python(cache, &probe.version),
+        image: image.clone(),
+        probe,
+        folders,
+    };
+    snapshots::write(&partial, &snapshot)?;
+    if dir.exists() {
+        std::fs::remove_dir_all(&dir)?;
+    }
+    std::fs::rename(&partial, &dir)?;
+    snapshots::make_current(target_dir, &image)?;
+    Ok(true)
+}
+
+/// Distinguishes probe containers.
+fn unique() -> String {
+    use std::sync::atomic::{AtomicU32, Ordering};
+    static COUNT: AtomicU32 = AtomicU32::new(0);
+    let secs = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH).map_or(0, |d| d.as_secs());
+    format!("{:x}-{}-{}", secs & 0xff_ffff, std::process::id(), COUNT.fetch_add(1, Ordering::Relaxed))
+}
@@ -0,0 +1,29 @@
+//! SSH configuration commands shared by the desktop shell's IPC commands and the remote
+//! server ([`crate::rpc`]). A remote window connects from the server (deployment, database
+//! tunnels, run targets, SSH sessions), so the host keys it trusts and the passwords it is
+//! given belong to the server's [`ide_ssh::SshManager`], not the desktop's.
+use crate::rpc::Dispatcher;
+use ide_core::remote_settings::SshConfiguration;
+
+pub(crate) fn register(d: &mut Dispatcher) {
+    d.add("ssh_test", |c| async move {
+        let (config, secret) = (c.arg::<SshConfiguration>("config")?, c.arg::<Option<String>>("secret")?);
+        c.host.ssh.test(&config, secret).await
+    });
+    d.add("ssh_set_secret", |c| async move {
+        let (id, secret, save) = (c.arg::<String>("id")?, c.arg::<Option<String>>("secret")?, c.arg::<bool>("save")?);
+        c.host.ssh.set_secret(&id, secret, save);
+        Ok(())
+    });
+    d.add("ssh_password_saved", |c| async move { Ok(c.host.ssh.password_saved(&c.arg::<String>("key")?)) });
+    d.add("ssh_needs_secret", |c| async move {
+        let ssh = &c.host.ssh;
+        Ok(ssh.needs_secret(&ssh.config(&c.arg::<String>("id")?)?))
+    });
+    d.add("ssh_trust_host", |c| async move { c.host.ssh.trust_host(&c.arg::<String>("id")?).await });
+    d.add("ssh_connected", |c| async move { Ok(c.host.ssh.connected()) });
+    d.add("ssh_disconnect", |c| async move {
+        c.host.ssh.disconnect(&c.arg::<String>("id")?);
+        Ok(())
+    });
+}
@@ -22,6 +22,27 @@ pub async fn status(host: &Host, window: &str) -> IdeResult<Vec<FileStatus>> {
    .await
 }

+/// Changes of `paths` only: the dirty-scope refresh after a watcher batch. `paths` that belong
+/// to no repository are ignored, and an empty list is the full status.
+pub async fn status_paths(host: &Host, window: &str, paths: Vec<std::path::PathBuf>) -> IdeResult<Vec<FileStatus>> {
+    let project = host.project(window)?;
+    host.blocking(move || {
+        let settings = project.settings.effective();
+        if project.is_trusted() {
+            apply_git_executable(&settings);
+        }
+        let repos = project.repos();
+        if repos.is_empty() {
+            return Err(ide_core::IdeError::unavailable("project is not a git repository"));
+        }
+        for r in repos.all() {
+            r.set_ignored_names(settings.ignored_names());
+        }
+        repos.status_paths(&paths)
+    })
+    .await
+}
+
 mod commands;
 pub use commands::*;

@@ -585,6 +585,21 @@ pub async fn vcs_stage(host: &Host, window: &str, paths: Vec<PathBuf>) -> IdeRes
    blocking(move || per_backend(&project, &paths, None, |r, paths| r.stage(paths))).await
 }

+/// Adds `commit` to annotate's ignore list in `path`'s repository (the file `blame.ignoreRevsFile`
+/// names, else `.git-blame-ignore-revs`, which the local config then names).
+pub async fn vcs_ignore_blame_revision(host: &Host, window: &str, path: PathBuf, commit: String) -> IdeResult<()> {
+    host.require_trust(window)?;
+    let project = host.project(window)?;
+    blocking(move || {
+        let result = project.with_disk_sync(|| project.with_repo_of(&path, |r| r.ignore_blame_revision(&commit)));
+        if result.is_ok() {
+            project.sink.emit(ide_core::IdeEvent::VcsChanged { root: project.root.clone().into() });
+        }
+        result
+    })
+    .await
+}
+
 /// Project-host operation (also registered with the remote dispatcher).
 /// Returns the ignore files that were updated, so the UI can show them.
 pub async fn vcs_add_to_ignore(
@@ -792,12 +807,19 @@ pub async fn vcs_stash_push(
    message: Option<String>,
    include_untracked: bool,
    keep_index: bool,
+    paths: Option<Vec<PathBuf>>,
 ) -> IdeResult<()> {
    host.require_trust(window)?;
    let project = host.project(window)?;
+    let paths = paths.unwrap_or_default();
    blocking(move || {
-        project.with_repo_recorded(repo.as_deref(), Some("Git stash"), |r| {
-            r.stash_push(message.as_deref(), include_untracked, keep_index)
+        if paths.is_empty() {
+            return project.with_repo_recorded(repo.as_deref(), Some("Git stash"), |r| {
+                r.stash_push(message.as_deref(), include_untracked, keep_index, &[])
+            });
+        }
+        per_repo(&project, &paths, Some("Git stash"), |r, paths| {
+            r.stash_push(message.as_deref(), include_untracked, keep_index, paths)
        })
    })
    .await
@@ -1462,6 +1484,9 @@ pub(crate) fn register(d: &mut Dispatcher) {
    d.add("vcs_add_to_ignore", |c| async move {
        vcs_add_to_ignore(&c.host, &c.window, c.arg("paths")?, c.arg("destination")?).await
    });
+    d.add("vcs_ignore_blame_revision", |c| async move {
+        vcs_ignore_blame_revision(&c.host, &c.window, c.arg("path")?, c.arg("commit")?).await
+    });
    d.add("vcs_unstage", |c| async move { vcs_unstage(&c.host, &c.window, c.arg("paths")?).await });
    d.add("vcs_stage_patch", |c| async move { vcs_stage_patch(&c.host, &c.window, c.arg("patch")?).await });
    d.add("vcs_discard", |c| async move { vcs_discard(&c.host, &c.window, c.arg("paths")?).await });
@@ -1520,6 +1545,7 @@ pub(crate) fn register(d: &mut Dispatcher) {
            c.arg("message")?,
            c.arg("includeUntracked")?,
            c.arg("keepIndex")?,
+            c.arg("paths")?,
        )
        .await
    });
@@ -2,10 +2,106 @@

 use crate::Host;
 use ide_core::IdeResult;
+use ide_core::proxy_settings::{ProxyMode, ProxySettings};
 use std::path::Path;
+use std::time::Duration;
+
+/// Whether `url` names this machine (`localhost` or a loopback address).
+fn is_loopback(url: &reqwest::Url) -> bool {
+    let host = url.host_str().unwrap_or_default().trim_start_matches('[').trim_end_matches(']');
+    host.eq_ignore_ascii_case("localhost") || host.parse::<std::net::IpAddr>().is_ok_and(|ip| ip.is_loopback())
+}
+
+fn is_html(content_type: &str) -> bool {
+    let kind = content_type.split(';').next().unwrap_or_default().trim();
+    kind.eq_ignore_ascii_case("text/html") || kind.eq_ignore_ascii_case("application/xhtml+xml")
+}
+
+/// A client that reaches this machine only: no proxy, and a redirect is followed while it
+/// stays here (a dev server sending `/` to `/app/`).
+fn loopback_client() -> IdeResult<reqwest::Client> {
+    let direct = ProxySettings { mode: ProxyMode::None, ..ProxySettings::default() };
+    let stay = reqwest::redirect::Policy::custom(|attempt| {
+        if is_loopback(attempt.url()) && attempt.previous().len() < 5 { attempt.follow() } else { attempt.stop() }
+    });
+    ide_http::client::build_with_redirect(&direct, stay)
+}
+
+/// Whether `url`, a server on this machine, answers a browser with an HTML document: a page
+/// to open, as a dev server has, and not an API endpoint. Other hosts are never asked.
+pub async fn serves_page(url: &str) -> bool {
+    let Ok(url) = reqwest::Url::parse(url) else { return false };
+    if !matches!(url.scheme(), "http" | "https") || !is_loopback(&url) {
+        return false;
+    }
+    let Ok(client) = loopback_client() else { return false };
+    // A dev server may compile the page on this first request.
+    let request = client.get(url).header(reqwest::header::ACCEPT, "text/html").timeout(Duration::from_secs(10));
+    let Ok(response) = request.send().await else { return false };
+    let html = response
+        .headers()
+        .get(reqwest::header::CONTENT_TYPE)
+        .and_then(|value| value.to_str().ok())
+        .is_some_and(is_html);
+    response.status().is_success() && html
+}

 /// The URL serving `file`, under the window's project when it holds the file.
 pub async fn url(host: &Host, window: &str, file: &Path) -> IdeResult<String> {
    let root = host.project(window).ok().map(|p| p.root.clone());
    host.web.url_for(root.as_deref(), file).await
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use tokio::io::{AsyncReadExt, AsyncWriteExt};
+
+    /// A server on a free port that answers every request with `status` and `header`. It
+    /// listens on every interface, so that a test can reach it under a name that is not loopback.
+    async fn answering(status: &'static str, header: String) -> String {
+        let listener = tokio::net::TcpListener::bind("0.0.0.0:0").await.unwrap();
+        let port = listener.local_addr().unwrap().port();
+        tokio::spawn(async move {
+            while let Ok((mut socket, _)) = listener.accept().await {
+                let mut request = [0u8; 2048];
+                let _ = socket.read(&mut request).await;
+                let response =
+                    format!("HTTP/1.1 {status}\r\n{header}\r\nContent-Length: 2\r\nConnection: close\r\n\r\nok");
+                let _ = socket.write_all(response.as_bytes()).await;
+            }
+        });
+        format!("http://127.0.0.1:{port}/")
+    }
+
+    async fn server(status: &'static str, content_type: &'static str) -> String {
+        answering(status, format!("Content-Type: {content_type}")).await
+    }
+
+    async fn redirecting_to(location: &str) -> String {
+        answering("302 Found", format!("Location: {location}")).await
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn a_redirect_is_followed_on_this_machine_only() {
+        let page = server("200 OK", "text/html").await;
+        assert!(serves_page(&redirecting_to(&page).await).await);
+        // The same page under an address that is not loopback: it is not asked.
+        let elsewhere = page.replace("127.0.0.1", "0.0.0.0");
+        assert!(!serves_page(&redirecting_to(&elsewhere).await).await);
+    }
+
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn a_page_is_an_html_answer_from_this_machine() {
+        assert!(serves_page(&server("200 OK", "text/html; charset=utf-8").await).await);
+        assert!(serves_page(&server("200 OK", "Text/HTML").await.replace("127.0.0.1", "localhost")).await);
+        // An API, an error page and a port nothing listens on are not pages.
+        assert!(!serves_page(&server("200 OK", "application/json").await).await);
+        assert!(!serves_page(&server("404 Not Found", "text/html").await).await);
+        assert!(!serves_page("http://127.0.0.1:1/").await);
+        // Other machines are not asked at all.
+        assert!(!serves_page("http://example.com/").await);
+        assert!(!serves_page("ftp://localhost/").await);
+        assert!(!serves_page("not a url").await);
+    }
+}
@@ -1642,6 +1642,9 @@ impl HostApi for PluginApi {
    ) -> Result<(), HostError> {
        self.set_decorations(path, set, Vec::new(), item, true)
    }
+    fn file_icon_decorations(&self, set: &str, items: Vec<(PathBuf, String)>) -> Result<(), HostError> {
+        self.set_file_icon_decorations(set, items)
+    }
    fn vcs_log(
        &self,
        root: &Path,
@@ -4124,6 +4127,9 @@ impl PluginApi {
        {
            return Err(HostError::Invalid("a file note is one non-empty line of at most 200 characters".into()));
        }
+        if let Some(icon) = file.as_ref().and_then(|f| f.icon.as_ref()) {
+            ide_extension::validate_item_id(icon, "file icon id").map_err(HostError::Invalid)?;
+        }
        items.retain(|d| decoration_style(&d.style));
        if items.iter().any(|d| d.range.start > d.range.end) {
            return Err(HostError::Invalid("reversed decoration range".into()));
@@ -4132,24 +4138,14 @@ impl PluginApi {
            // The decoration follows the file, not the window's project: editors render
            // whatever they have open, including files outside every project root. The
            // set's root stays the path's own (deepest open) project for tree filtering.
-            let root = self
-                .shared
-                .workspace()
-                .map(|w| {
-                    w.projects()
-                        .into_iter()
-                        .filter(|root| path.starts_with(root))
-                        .max_by_key(|root| root.components().count())
-                })
-                .unwrap_or_default()
-                .unwrap_or_else(|| path.parent().map(Path::to_path_buf).unwrap_or_else(|| path.to_path_buf()));
+            let root = self.decoration_root(path);
            Some(super::DecorationSet {
                root: root.into(),
                path: ide_core::IpcPath(path.to_path_buf()),
                set_id: set.into(),
                tree,
                items,
-                file: file.filter(|f| f.note.is_some() || decoration_style(&f.style)),
+                file: file.filter(|f| f.note.is_some() || f.icon.is_some() || decoration_style(&f.style)),
            })
        } else {
            None
@@ -4177,6 +4173,60 @@ impl PluginApi {
        self.shared.sink.emit(None, PluginEvent::DecorationsChanged { plugin_id: self.id().into(), sets });
        Ok(())
    }
+
+    fn decoration_root(&self, path: &Path) -> PathBuf {
+        self.shared
+            .workspace()
+            .map(|w| {
+                w.projects()
+                    .into_iter()
+                    .filter(|root| path.starts_with(root))
+                    .max_by_key(|root| root.components().count())
+            })
+            .unwrap_or_default()
+            .unwrap_or_else(|| path.parent().map(Path::to_path_buf).unwrap_or_else(|| path.to_path_buf()))
+    }
+
+    fn set_file_icon_decorations(&self, set: &str, items: Vec<(PathBuf, String)>) -> Result<(), HostError> {
+        if set.is_empty() || set.len() > 128 {
+            return Err(HostError::Invalid("set id must be 1-128 bytes".into()));
+        }
+        if items.len() > 10_000 {
+            return Err(HostError::Invalid("at most 10000 file icons per set".into()));
+        }
+        let mut by_path = BTreeMap::new();
+        for (path, icon) in items {
+            ide_extension::validate_item_id(&icon, "file icon id").map_err(HostError::Invalid)?;
+            by_path.insert(path, icon);
+        }
+        let mut all = self.shared.decorations.lock();
+        let mut sets = all.get(self.id()).cloned().unwrap_or_default();
+        sets.retain(|s| !(s.tree && s.set_id == set));
+        for (path, icon) in by_path {
+            let root = self.decoration_root(&path);
+            sets.push(super::DecorationSet {
+                root: root.into(),
+                path: ide_core::IpcPath(path),
+                set_id: set.into(),
+                tree: true,
+                items: Vec::new(),
+                file: Some(ide_plugin::FileDecoration {
+                    badge: None,
+                    style: String::new(),
+                    tooltip: None,
+                    note: None,
+                    icon: Some(icon),
+                }),
+            });
+        }
+        let names: BTreeSet<_> = sets.iter().filter(|s| s.tree).map(|s| &s.set_id).collect();
+        if names.len() > 50 || serde_json::to_vec(&sets).map_err(failed)?.len() > 4 << 20 {
+            return Err(HostError::Invalid("decoration sets exceed plugin limits".into()));
+        }
+        all.insert(self.id().into(), sets.clone());
+        self.shared.sink.emit(None, PluginEvent::DecorationsChanged { plugin_id: self.id().into(), sets });
+        Ok(())
+    }
 }
 fn decoration_style(style: &str) -> bool {
    matches!(
@@ -4330,7 +4380,8 @@ mod workbench_tests {
                    badge: Some("abc".into()),
                    style: "info".into(),
                    tooltip: None,
-                    note: None
+                    note: None,
+                    icon: None,
                })
            )
            .is_err()
@@ -4340,6 +4391,7 @@ mod workbench_tests {
            style: String::new(),
            tooltip: Some("why".into()),
            note: Some(text.into()),
+            icon: None,
        };
        api.file_decorations(Some(&path), "notes", Some(note("entry point"))).unwrap();
        let notes = |api: &PluginApi| {
@@ -4353,6 +4405,18 @@ mod workbench_tests {
        for bad in ["", "two\nlines", &"x".repeat(201)] {
            assert!(api.file_decorations(Some(&path), "notes", Some(note(bad))).is_err(), "{bad:?}");
        }
+        api.file_icon_decorations(
+            "icons",
+            vec![(path.clone(), "helm-chart".into()), (root.join("chart"), "helm-dir".into())],
+        )
+        .unwrap();
+        let icons = api.shared.decoration_sets()["test"]
+            .iter()
+            .filter(|s| s.tree && s.set_id == "icons")
+            .filter_map(|s| s.file.as_ref().and_then(|f| f.icon.clone()))
+            .collect::<Vec<_>>();
+        assert_eq!(icons.len(), 2);
+        assert!(api.file_icon_decorations("icons", vec![(path.clone(), "BAD ID".into())]).is_err());
        api.shared.clear_plugin("test", true);
        assert!(api.shared.decoration_sets().is_empty());
    }
@@ -77,9 +77,22 @@ pub(super) fn validate_reply(reply: &ContentTabReply) -> Result<(), HostError> {
    Ok(())
 }

+/// Largest side of a plugin diff, in UTF-16 code units (earlier hosts allowed 1 MiB).
+pub(super) const MAX_DIFF_SIDE: usize = 8 << 20;
+
+fn diff_side(value: &str, side: &str) -> Result<(), HostError> {
+    if value.contains('\0') {
+        return Err(HostError::Invalid(format!("the {side} side of the diff contains NUL")));
+    }
+    if value.encode_utf16().count() > MAX_DIFF_SIDE {
+        return Err(HostError::Invalid(format!("diff too large: the {side} side is over {} MiB", MAX_DIFF_SIDE >> 20)));
+    }
+    Ok(())
+}
+
 pub(super) fn validate_diff(diff: &ide_plugin::ContentDiff) -> Result<(), HostError> {
-    body(&diff.left)?;
-    body(&diff.right)?;
+    diff_side(&diff.left, "left")?;
+    diff_side(&diff.right, "right")?;
    for value in [&diff.left_label, &diff.right_label].into_iter().flatten() {
        label(value, 128)?;
    }
@@ -571,3 +584,25 @@ impl PluginHost {
        }
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn diff(left: String, right: String) -> ide_plugin::ContentDiff {
+        ide_plugin::ContentDiff { left, right, left_label: None, right_label: None, title: None }
+    }
+
+    #[test]
+    fn diff_sides_up_to_the_limit_open_and_larger_ones_say_why() {
+        assert!(validate_diff(&diff("x".repeat(5 << 20), "y".repeat(MAX_DIFF_SIDE))).is_ok());
+        let err = validate_diff(&diff(String::new(), "y".repeat(MAX_DIFF_SIDE + 1))).unwrap_err();
+        assert!(
+            matches!(&err, HostError::Invalid(m) if m == "diff too large: the right side is over 8 MiB"),
+            "{err:?}"
+        );
+        assert!(
+            matches!(validate_diff(&diff("a\0".into(), String::new())), Err(HostError::Invalid(m)) if m.contains("NUL"))
+        );
+    }
+}
@@ -396,15 +396,37 @@ impl PluginHost {
        }
    }

+    pub(super) fn has_document_providers(&self, kind: ProviderKind, doc: &ProviderDocument) -> bool {
+        self.provider_plugins(kind, &doc.language)
+            .into_iter()
+            .any(|p| p.dev_root.as_ref().is_none_or(|r| doc.path.starts_with(r)))
+    }
+
    pub fn provide_completion(
        &self,
        doc: &ProviderDocument,
        at: ide_core::Pos,
        trigger: Option<&str>,
    ) -> Vec<(String, CompletionItem)> {
-        self.feature_documents(doc, Some(at))
+        self.provide_completion_for_editor(doc, at, trigger).1
+    }
+
+    pub(crate) fn provide_completion_for_editor(
+        &self,
+        doc: &ProviderDocument,
+        at: ide_core::Pos,
+        trigger: Option<&str>,
+    ) -> (bool, Vec<(String, CompletionItem)>) {
+        // An injection-capable outer document (e.g. SQL embedded in text) may complete at other
+        // positions even when `at` is outside an injection, so avoid marking document-wide backoff.
+        let mut covered = self.has_document_providers(ProviderKind::Injections, doc);
+        let items = self
+            .feature_documents(doc, Some(at))
            .into_iter()
            .flat_map(|(doc, bounds)| {
+                if self.has_document_providers(ProviderKind::Completion, &doc) {
+                    covered = true;
+                }
                let (d, t) = (Arc::new(doc.clone()), trigger.map(str::to_owned));
                self.document_calls(ProviderKind::Completion, &doc, move |rt, timeout| {
                    rt.provide_completion(&d, at, t.as_deref(), timeout)
@@ -419,7 +441,8 @@ impl PluginHost {
                    Some((p, i))
                })
            })
-            .collect()
+            .collect();
+        (covered, items)
    }

    pub fn provide_code_actions(
@@ -743,6 +743,7 @@ pub(super) fn custom_editor(pkg: &Package, decl: toml::Value) -> Result<UiDecl,
 #[serde(rename_all = "camelCase", deny_unknown_fields)]
 struct FileIconDecl {
    id: String,
+    #[serde(default)]
    patterns: Vec<String>,
    icon: PathBuf,
    #[serde(default)]
@@ -754,13 +755,19 @@ pub fn file_icon_asset(id: &str, dark: bool) -> String {
    format!("fileIcon/{id}/{}", if dark { "dark" } else { "light" })
 }

-/// `[[contributes.fileIcons]]`: an icon for the files matching `patterns`,
-/// whatever icon theme is in use (the user's own file type icons still win).
+/// `[[contributes.fileIcons]]`: an icon for the files matching `patterns` (or
+/// assigned dynamically through `decorations.set-file-icon` when `patterns` is
+/// omitted in API 1.8), whatever icon theme is in use (the user's own file type
+/// icons still win).
 pub(super) fn file_icon(pkg: &Package, decl: toml::Value) -> Result<UiDecl, String> {
    let d: FileIconDecl = decode(FILE_ICONS, decl)?;
    validate_item_id(&d.id, "file icon id")?;
    let what = format!("file icon {:?}", d.id);
-    file_patterns(&d.patterns, &what)?;
+    if d.patterns.is_empty() {
+        pkg.manifest.needs_api("contributes.fileIcons without patterns", 8)?;
+    } else {
+        file_patterns(&d.patterns, &what)?;
+    }
    let mut files = Vec::new();
    let mut assets = Vec::new();
    for (path, dark) in [(Some(&d.icon), false), (d.icon_dark.as_ref(), true)] {
@@ -769,8 +776,16 @@ pub(super) fn file_icon(pkg: &Package, decl: toml::Value) -> Result<UiDecl, Stri
        assets.push((file_icon_asset(&d.id, dark), svg));
        files.push(path.clone());
    }
-    let json = serde_json::json!({ "id": d.id, "patterns": d.patterns, "dark": d.icon_dark.is_some() });
-    let mut out = UiDecl::new(d.id.clone(), d.patterns.join(", "), json);
+    let bytes = serde_json::to_vec(&assets).map_err(|e| e.to_string())?;
+    let revision = blake3::hash(&bytes).to_hex().to_string();
+    let json = serde_json::json!({
+        "id": d.id,
+        "patterns": d.patterns,
+        "dark": d.icon_dark.is_some(),
+        "revision": revision,
+    });
+    let label = if d.patterns.is_empty() { d.id.clone() } else { d.patterns.join(", ") };
+    let mut out = UiDecl::new(d.id.clone(), label, json);
    out.files = files;
    out.assets = assets;
    Ok(out)
@@ -88,6 +88,9 @@ impl Host {
        let root = dunce::canonicalize(root)?;
        let opening = self.opening(window);
        let _opening = opening.lock();
+        // Untitled buffers belong to the window, not a project: they follow it
+        // into the project's fresh document registry.
+        let carried = self.project(window).ok().map(|prev| prev.documents.untitled_buffers()).unwrap_or_default();
        // Reject a damaged manifest before replacing the currently open project.
        let is_workspace = ide_workspace::workspace::Workspace::load(&root)?.is_some();
        // The window reloaded (or asked again) for the project it already has: keep
@@ -174,6 +177,7 @@ impl Host {
                let root = member.as_ref().unwrap_or(window_root);
                ide_sdk::apply::server_launch_overrides(cfg, &effective);
                ide_sdk::apply::configure_server(cfg, root, server_root, &effective);
+                crate::ops::sdk::container_python::configure_server(cfg, &data_dir, root, &effective);
                if cfg.name == "jdtls" {
                    // A workspace member keeps its build model under its own key (Build Project).
                    let cache = match &member {
@@ -447,6 +451,11 @@ impl Host {
                            .collect();
                        matches!(rest.as_slice(), [first, ..] if first == "worktrees" && rest.len() <= 2)
                    });
+                    // A repository folder moved or restored into the project: no `.git` event is
+                    // written inside it before the watcher sees the new directory, its creation is
+                    // the signal. A `git clone` / `git init` inside the project already arrives
+                    // through the `.git` paths above; this covers the whole tree being brought in.
+                    git_dirs |= batch.created.iter().any(|p| p.join(".git").exists());
                    if git_dirs {
                        scan_repositories(&root, &repos, &settings, &sink, &build_cache);
                    }
@@ -615,6 +624,9 @@ impl Host {
            }));
        }
        self.insert_project(window, project.clone());
+        for (key, text, dirty) in &carried {
+            let _ = project.documents.restore_untitled_buffer(key, text, *dirty);
+        }
        project.lsp.prewarm_java_configuration();
        if let Some(bridge) = &project.kotlin_bridge {
            bridge.start(&self.runtime);
@@ -625,6 +637,7 @@ impl Host {
        if let Some(cmd) = post_start {
            self.environment.spawn_post_start(cmd, project.root.clone(), project.sink.clone());
        }
+        crate::ops::sdk::container_python::ensure(self, &project);
        Ok(project)
    }

@@ -659,6 +672,7 @@ impl Host {
                        .join(project_key)
                }),
                models_file: self.data_dir.join("agents").join("models.json"),
+                catalogs: self.agent_catalogs.clone(),
                custom_agents_dir: Some(self.config_dir.join("agents")),
                home_dir: dirs::home_dir(),
                env_secrets: Some(Arc::new(AgentEnvSecrets {
@@ -695,12 +709,29 @@ impl Host {
            return Err(IdeError::invalid(format!("{} is a folder", file.display())));
        }
        let dir = file.parent().map(Path::to_path_buf).ok_or_else(|| IdeError::invalid("no parent folder"))?;
+        let watch = dir.clone();
+        self.open_light_in(window, dir, Some(&watch))
+    }
+
+    /// LightEdit without a file (a welcome window's File › New File): rooted
+    /// at the user's home folder, watching nothing until a buffer is saved
+    /// into a real folder ([`Project::watch_light_dir`]).
+    pub fn open_light_empty(&self, window: &str) -> IdeResult<Arc<Project>> {
+        let dir = dirs::home_dir().unwrap_or_else(std::env::temp_dir);
+        self.open_light_in(window, dir, None)
+    }
+
+    fn open_light_in(&self, window: &str, dir: PathBuf, watch_dir: Option<&Path>) -> IdeResult<Arc<Project>> {
        let opening = self.opening(window);
        let _opening = opening.lock();
+        // Untitled buffers belong to the window: they follow it out of a project.
+        let carried = self.project(window).ok().map(|prev| prev.documents.untitled_buffers()).unwrap_or_default();
        if let Ok(current) = self.project(window)
            && current.light
        {
-            current.watch_light_dir(&dir);
+            if let Some(dir) = watch_dir {
+                current.watch_light_dir(dir);
+            }
            return Ok(current);
        }
        self.close_project(window);
@@ -719,7 +750,16 @@ impl Host {
        let syntax = Arc::new(SyntaxCache::new(self.syntax()));
        documents.add_observer(Arc::new(SyntaxObserver(syntax.clone())));
        documents.add_observer(Arc::new(HistoryObserver(history.clone())));
-        let watcher = light_watcher(&dir, &sink, &documents, &history)?;
+        let watcher = match watch_dir {
+            Some(dir) => light_watcher(dir, &sink, &documents, &history)?,
+            // A quiet private folder stands in until the first save brings a
+            // real folder in.
+            None => {
+                let idle = self.local_data_dir.join("light-edit");
+                std::fs::create_dir_all(&idle)?;
+                light_watcher(&idle, &sink, &documents, &history)?
+            }
+        };
        let project_key = project_key(&dir);
        let (db, http_history, agents) = self.project_services(&dir, &project_key, &settings, &sink);
        let notebooks = crate::notebook::NotebookService::new(
@@ -765,8 +805,11 @@ impl Host {
            light: true,
            root: dir,
        });
-        tracing::info!("window {window} edits {} without a project", file.display());
+        tracing::info!("window {window} edits {} without a project", project.root.display());
        self.insert_project(window, project.clone());
+        for (key, text, dirty) in &carried {
+            let _ = project.documents.restore_untitled_buffer(key, text, *dirty);
+        }
        Ok(project)
    }
 }
@@ -864,6 +907,20 @@ fn scan_repositories(
    sink: &SharedSink,
    build_cache: &Path,
 ) {
+    match discover_repositories(root, settings, build_cache) {
+        Ok(found) => {
+            if found.roots() != repos.read().roots() {
+                *repos.write() = found;
+                sink.emit(IdeEvent::VcsChanged { root: root.to_path_buf().into() });
+            }
+        }
+        Err(e) => tracing::warn!("looking for git repositories: {e}"),
+    }
+}
+
+/// The repository containing `root` and those nested below it or below a content root.
+/// The project-open scan and the watcher's rescan share these skip rules.
+fn discover_repositories(root: &Path, settings: &SettingsStore, build_cache: &Path) -> IdeResult<Repos> {
    let ignored = settings.effective().ignored_names();
    let skip = |p: &Path| {
        p.file_name().is_some_and(|n| {
@@ -875,15 +932,7 @@ fn scan_repositories(
    };
    let mut roots = vec![root.to_path_buf()];
    roots.extend(content_roots(&settings.effective(), root, build_cache));
-    match Repos::discover_roots(&roots, &skip) {
-        Ok(found) => {
-            if found.roots() != repos.read().roots() {
-                *repos.write() = found;
-                sink.emit(IdeEvent::VcsChanged { root: root.to_path_buf().into() });
-            }
-        }
-        Err(e) => tracing::warn!("looking for git repositories: {e}"),
-    }
+    Repos::discover_roots(&roots, &skip)
 }

 impl Project {
@@ -1444,7 +1493,7 @@ fn content_root_watcher(
 ) -> Option<Watcher> {
    let (kotlin_bridge, phpstan) = (kotlin_bridge.cloned(), phpstan.cloned());
    let (index, documents, history, lsp) = (index.clone(), documents.clone(), history.clone(), lsp.clone());
-    let root = dir.to_path_buf();
+    let (root, events) = (dir.to_path_buf(), sink.clone());
    Watcher::start(
        dir,
        excludes.to_vec(),
@@ -1466,6 +1515,11 @@ fn content_root_watcher(
            }
            documents.on_disk_changed(&[&changed[..], &ignored].concat());
            record_external_changes(&history, &changed, &batch.removed);
+            // A member outside the project folder: its repository changes (commit, checkout,
+            // fetch, pull) reach the UI only through this watcher.
+            if batch.vcs.iter().any(|p| vcs_path_changed(p)) {
+                events.emit(IdeEvent::VcsChanged { root: root.clone().into() });
+            }
        }),
    )
    .map_err(|e| tracing::warn!("content root watcher {}: {e}", dir.display()))
@@ -218,6 +218,13 @@ impl Dispatcher {
        })
        .add("fs_read_text", |c| async move { ops::fs::read_text(&c.host, &c.window, c.arg("path")?).await })
        .add("doc_open", |c| async move { ops::doc::open(&c.host, &c.window, c.arg("path")?).await })
+        .add("doc_open_untitled", |c| async move {
+            ops::doc::open_untitled(&c.host, &c.window, c.arg::<Option<String>>("name")?).await
+        })
+        .add(
+            "doc_save_as",
+            |c| async move { ops::doc::save_as(&c.host, &c.window, c.arg("doc")?, c.arg("path")?).await },
+        )
        .add("doc_close", |c| async move {
            ops::doc::blocking(move || ops::doc::close(&c.host, &c.window, c.arg("doc")?)).await
        })
@@ -270,7 +277,8 @@ impl Dispatcher {
        .add("run_resize", |c| async move { ops::run::resize(&c.host, c.arg("id")?, c.arg("cols")?, c.arg("rows")?) })
        .add("run_close_stdin", |c| async move { ops::run::close_stdin(&c.host, c.arg("id")?) })
        .add("run_list", |c| async move { Ok(ops::run::list(&c.host)) })
-        .add("vcs_status", |c| async move { ops::vcs::status(&c.host, &c.window).await });
+        .add("vcs_status", |c| async move { ops::vcs::status(&c.host, &c.window).await })
+        .add("vcs_status_paths", |c| async move { ops::vcs::status_paths(&c.host, &c.window, c.arg("paths")?).await });
        ops::register_all(&mut d);
        d
    }
@@ -289,6 +289,7 @@ impl crate::Host {
                }
            }
            project.lsp.reconfigure().await;
+            crate::ops::sdk::container_python::ensure(self, &project);
            project.sink.emit(ide_core::IdeEvent::ProjectTrustChanged { root: project.root.clone().into(), trusted });
        }
        Ok(())
@@ -357,6 +358,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
            | "docker_set_registry_password"
            | "docker_run_env"
            | "db_console_path"
+            | "db_consoles"
            | "db_export_file"
            | "vcs_write_patch"
            | "app_metrics"
@@ -399,6 +401,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
            | "web_unresolved_references"
            | "project_rename"
            | "light_edit_open"
+            | "light_edit_open_untitled"
            | "workspace_create"
            | "workspace_discover_projects"
            | "workspace_update"
@@ -475,6 +478,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
            | "vcs_clone"
            | "vcs_init"
            | "vcs_status"
+            | "vcs_status_paths"
            | "vcs_roots"
            | "vcs_branch_info"
            | "vcs_line_hunks"
@@ -0,0 +1,98 @@
+//! Separate project windows share discovery and its backend-enforced cooldown.
+#![cfg(unix)]
+
+use ide_agent::AgentEvent;
+use ide_core::NullSink;
+use ide_host::{Host, HostConfig, ops};
+use std::sync::Arc;
+use std::time::Duration;
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn windows_share_model_discovery_and_manual_refresh_cooldown() {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = tmp.path().join("project");
+    let config = tmp.path().join("config");
+    std::fs::create_dir_all(&root).unwrap();
+    std::fs::create_dir_all(config.join("agents")).unwrap();
+    let script = tmp.path().join("catalog.sh");
+    std::fs::write(
+        &script,
+        r#"#!/bin/sh
+printf 'launch\n' >> "${0%/*}/launches"
+while IFS= read -r line; do
+    case "$line" in
+        *'"id":'*) rest=${line#*\"id\":}; id=${rest%%,*}; id=${id%%\}*} ;;
+        *) continue ;;
+    esac
+    case "$line" in
+        *'"method":"initialize"'*)
+            printf '{"jsonrpc":"2.0","id":%s,"result":{"protocolVersion":1,"agentCapabilities":{}}}\n' "$id" ;;
+        *'"method":"session/new"'*)
+            while [ ! -f "${0%/*}/release" ]; do sleep 0.01; done
+            printf '{"jsonrpc":"2.0","id":%s,"result":{"sessionId":"catalog","configOptions":[{"id":"model","name":"Model","category":"model","type":"select","currentValue":"new-model","options":[{"value":"new-model","name":"New model"}]}]}}\n' "$id" ;;
+    esac
+done
+"#,
+    )
+    .unwrap();
+    std::fs::write(
+        config.join("agents/catalog-test.toml"),
+        format!(
+            "name = \"Catalog test\"\ncommand = \"/bin/sh\"\nargs = [{}]\n",
+            serde_json::to_string(&script).unwrap()
+        ),
+    )
+    .unwrap();
+    let host = Host::new(HostConfig {
+        config_dir: config,
+        data_dir: tmp.path().join("data"),
+        local_data_dir: tmp.path().join("local"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new(|_| Arc::new(NullSink)),
+        owner: |window| window,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    });
+    host.trust.decide(&root, true, false).unwrap();
+    host.open_project("first", &root).unwrap();
+    host.open_project("second", &root).unwrap();
+    let (send, mut events) = tokio::sync::mpsc::unbounded_channel();
+    for window in ["first", "second"] {
+        let send = send.clone();
+        host.project(window).unwrap().agents.subscribe(Arc::new(move |event| {
+            if let AgentEvent::ModelCatalog { catalog } = event {
+                let _ = send.send((window, catalog));
+            }
+        }));
+    }
+    for _ in 0..20 {
+        for window in ["first", "second"] {
+            let state = ops::agent::refresh_models(&host, window, "catalog-test".into(), true).unwrap();
+            assert!(state.refreshing);
+        }
+    }
+    std::fs::write(tmp.path().join("release"), "").unwrap();
+    let completed = tokio::time::timeout(Duration::from_secs(10), async {
+        let mut windows = std::collections::HashSet::new();
+        while windows.len() < 2 {
+            let (window, catalog) = events.recv().await.expect("catalog event stream closed");
+            if !catalog.refreshing && catalog.refreshed_at_ms.is_some() {
+                assert!(catalog.error.is_none(), "{:?}", catalog.error);
+                windows.insert(window);
+            }
+        }
+    })
+    .await;
+    assert!(completed.is_ok(), "both windows must receive the completed catalog");
+    for _ in 0..20 {
+        for window in ["first", "second"] {
+            let catalog = ops::agent::refresh_models(&host, window, "catalog-test".into(), true).unwrap();
+            assert!(!catalog.refreshing);
+            assert!(catalog.retry_at_ms.is_some());
+            let models = catalog.config.iter().find(|o| o.category.as_deref() == Some("model")).unwrap();
+            assert_eq!(models.values[0].value, "new-model");
+        }
+    }
+    assert_eq!(std::fs::read_to_string(tmp.path().join("launches")).unwrap(), "launch\n");
+}
@@ -0,0 +1,174 @@
+//! A Compose run target as the Python interpreter, against a real daemon and the real
+//! basedpyright. Ignored by default: `OPENIDEA_DOCKER_TEST_DIR` names an empty folder the
+//! daemon can bind-mount (on this machine, or at the same path in a VM such as OrbStack's),
+//! `docker` with the Compose plugin and `basedpyright-langserver` must be on `PATH`, and
+//! this machine's Python must not have Django installed.
+#![cfg(unix)]
+
+use ide_core::IdeEvent;
+use ide_host::{Host, HostConfig, ops};
+use ide_run::{OutputChunk, RunConfig};
+use std::path::{Path, PathBuf};
+use std::process::Command;
+use std::sync::{Arc, Mutex};
+use std::time::{Duration, Instant};
+
+const WINDOW: &str = "main";
+type Events = Arc<Mutex<Vec<IdeEvent>>>;
+
+fn host(base: &Path, events: &Events) -> Arc<Host> {
+    Arc::new(Host::new(HostConfig {
+        config_dir: base.join("config"),
+        data_dir: base.join("data"),
+        local_data_dir: base.join("data"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new({
+            let events = events.clone();
+            move |_| {
+                let events = events.clone();
+                Arc::new(move |e: IdeEvent| events.lock().unwrap().push(e))
+            }
+        }),
+        owner: |w| w,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    }))
+}
+
+/// basedpyright's latest diagnostics of `path` once `done` accepts them.
+async fn diagnostics(events: &Events, path: &Path, timeout: Duration, done: impl Fn(&[String]) -> bool) -> Vec<String> {
+    let deadline = Instant::now() + timeout;
+    loop {
+        let latest = events.lock().unwrap().iter().rev().find_map(|e| match e {
+            IdeEvent::Diagnostics { path: p, items, source } if **p == *path && source.contains("basedpyright") => {
+                Some(items.iter().map(|d| d.message.clone()).collect::<Vec<_>>())
+            }
+            _ => None,
+        });
+        if let Some(messages) = &latest
+            && done(messages)
+        {
+            return messages.clone();
+        }
+        assert!(Instant::now() < deadline, "timed out; last diagnostics: {latest:?}");
+        tokio::time::sleep(Duration::from_millis(500)).await;
+    }
+}
+
+fn unresolved(messages: &[String]) -> bool {
+    messages.iter().any(|m| m.contains("\"django") && m.contains("could not be resolved"))
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+#[ignore = "requires a Docker daemon, basedpyright and OPENIDEA_DOCKER_TEST_DIR"]
+async fn compose_target_is_the_python_interpreter() {
+    let root = PathBuf::from(std::env::var("OPENIDEA_DOCKER_TEST_DIR").expect("OPENIDEA_DOCKER_TEST_DIR"));
+    let root = dunce::canonicalize(root).unwrap();
+    let files = [
+        ("compose.yaml", "services:\n  web:\n    build: .\n    volumes:\n      - .:/app\n    working_dir: /app\n"),
+        (
+            "Dockerfile",
+            "FROM python:3.12-slim\nCOPY requirements.txt /tmp/requirements.txt\n\
+             RUN pip install --no-cache-dir -r /tmp/requirements.txt\n",
+        ),
+        ("requirements.txt", "Django==5.1.3\n"),
+        (
+            "app/main.py",
+            "import django\nfrom django.http import HttpResponse\n\nprint(django.get_version(), HttpResponse)\n",
+        ),
+    ];
+    for (path, text) in files {
+        std::fs::create_dir_all(root.join(path).parent().unwrap()).unwrap();
+        std::fs::write(root.join(path), text).unwrap();
+    }
+    let main = root.join("app/main.py");
+    let state = tempfile::tempdir().unwrap();
+    let events: Events = Arc::default();
+    let host = host(state.path(), &events);
+    host.trust.decide(&root, true, false).unwrap();
+    host.open_project(WINDOW, &root).unwrap();
+    let set = |key: &str, value: serde_json::Value| {
+        ops::project::set_settings(
+            &host,
+            WINDOW,
+            ide_workspace::settings::SettingsScope::Project,
+            key,
+            &value.to_string(),
+        )
+        .unwrap();
+    };
+    set("runTargets", serde_json::json!([{ "kind": "compose", "id": "web", "name": "Compose web", "service": "web" }]));
+
+    // A local interpreter: Django is only in the image.
+    ops::doc::open(&host, WINDOW, main.clone()).await.unwrap();
+    let before = diagnostics(&events, &main, Duration::from_secs(120), unresolved).await;
+    eprintln!("local interpreter: {before:?}");
+
+    // The run target as the interpreter: a snapshot is taken in the background, then the
+    // server restarts with the copied site-packages as `extraPaths`.
+    set("languages.python.interpreter", serde_json::json!("target:web"));
+    let after = diagnostics(&events, &main, Duration::from_secs(900), |m| !unresolved(m)).await;
+    eprintln!("run target interpreter: {after:?}");
+    assert!(after.iter().all(|m| !m.contains("could not be resolved")), "{after:?}");
+
+    let info = ops::sdk::sdk_container_python(&host, WINDOW).unwrap().expect("a run target interpreter");
+    eprintln!("snapshot: version {:?}, image {:?}, folders {:?}", info.version, info.image, info.folders);
+    assert_eq!(info.name, "Compose web");
+    assert!(info.version.as_deref().is_some_and(|v| v.starts_with("3.12.")), "{info:?}");
+    assert!(info.packages.iter().any(|p| p.name == "Django" && p.version == "5.1.3"), "{:?}", info.packages);
+    let site = info.folders.iter().find(|f| f.0.ends_with("site-packages")).expect("site-packages copied");
+    assert!(site.0.join("django/__init__.py").is_file());
+    assert!(site.0.starts_with(state.path().join("data/container-python")), "{site:?}");
+    let servers = ops::lsp::lsp_servers(&host, WINDOW).unwrap();
+    eprintln!("servers: {:?}", servers.iter().map(|s| (&s.name, s.status)).collect::<Vec<_>>());
+
+    // Run: a Python configuration without its own target runs in the container.
+    let out = Arc::new(Mutex::new(String::new()));
+    let sink = out.clone();
+    let config = RunConfig {
+        id: "main".into(),
+        name: "main".into(),
+        kind: "python".into(),
+        command: "python3".into(),
+        args: vec!["app/main.py".into()],
+        cwd: None,
+        env: Default::default(),
+        detected: false,
+        is_test: false,
+        debug_adapter: None,
+        allow_parallel: false,
+        extras: Default::default(),
+    };
+    ops::run::start(
+        &host,
+        WINDOW,
+        config,
+        Arc::new(move |chunk| match chunk {
+            OutputChunk::Stdout { text } | OutputChunk::Stderr { text } | OutputChunk::System { text } => {
+                sink.lock().unwrap().push_str(&text)
+            }
+        }),
+    )
+    .await
+    .unwrap();
+    for _ in 0..1200 {
+        if out.lock().unwrap().contains("Process finished") {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(100)).await;
+    }
+    let out = out.lock().unwrap().clone();
+    eprintln!("run output: {out}");
+    assert!(out.contains("5.1.3") && out.contains("exit code 0"), "{out}");
+
+    // Refresh takes a new snapshot of the same image; nothing is left running.
+    let refreshed = ops::sdk::sdk_container_python_refresh(&host, WINDOW).await.unwrap().unwrap();
+    assert_eq!(refreshed.image, info.image);
+    let probes = Command::new("docker")
+        .args(["ps", "--all", "--quiet", "--filter", "label=openidea.python-probe=true"])
+        .output()
+        .unwrap();
+    assert_eq!(String::from_utf8_lossy(&probes.stdout).trim(), "", "probe containers are removed");
+    Command::new("docker").args(["compose", "down", "--rmi", "local"]).current_dir(&root).status().unwrap();
+}
@@ -0,0 +1,37 @@
+use ide_core::NullSink;
+use ide_host::ops::db;
+use ide_host::{Host, HostConfig};
+use std::sync::Arc;
+
+#[tokio::test]
+async fn new_query_consoles_are_numbered_after_the_default_one() {
+    let tmp = tempfile::tempdir().unwrap();
+    let base = tmp.path();
+    let host = Arc::new(Host::new(HostConfig {
+        config_dir: base.join("config"),
+        data_dir: base.join("data"),
+        local_data_dir: base.join("data"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new(|_| Arc::new(NullSink)),
+        owner: |w| w,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    }));
+    let names = |paths: Vec<ide_core::IpcPath>| -> Vec<String> {
+        paths.iter().map(|p| p.0.file_name().unwrap().to_string_lossy().into_owned()).collect()
+    };
+    assert!(db::consoles(&host, "pg", false).unwrap().is_empty());
+    // The first new console is the default one, then console_1, console_2…
+    assert_eq!(names(db::consoles(&host, "pg", true).unwrap()), ["console.sql"]);
+    assert_eq!(names(db::consoles(&host, "pg", true).unwrap()), ["console.sql", "console_1.sql"]);
+    let all = db::consoles(&host, "pg", true).unwrap();
+    assert_eq!(names(all.clone()), ["console.sql", "console_1.sql", "console_2.sql"]);
+    // Numbers sort numerically, and the default console path is the first one.
+    std::fs::write(all[0].0.with_file_name("console_10.sql"), "").unwrap();
+    assert_eq!(names(db::consoles(&host, "pg", false).unwrap())[3], "console_10.sql");
+    assert_eq!(db::console_path(&host, "pg").unwrap().0, all[0].0);
+    // Each database of a source has its own consoles.
+    assert!(db::consoles(&host, "pg:other", false).unwrap().is_empty());
+    assert!(db::consoles(&host, "../x", true).is_err());
+}
@@ -179,3 +179,73 @@ async fn light_notebooks_open_without_interpreter_detection_or_execution() {
    assert!(!bin.join("python.probed").exists());
    host.shutdown().await;
 }
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn untitled_buffers_reach_the_disk_through_save_as() {
+    let tmp = tempfile::tempdir().unwrap();
+    let tmp_root = dunce::canonicalize(tmp.path()).unwrap();
+    let dir = tmp_root.join("notes");
+    let host = host(&tmp_root.join("app"));
+
+    // A window with no file (a welcome screen's File › New File): rooted at the
+    // home folder, no watcher yet, doc commands work.
+    let empty = host.open_light_empty("main").unwrap();
+    assert!(empty.light);
+    let untitled = ops::doc::open_untitled(&host, "main", None).await.unwrap();
+    assert_eq!(untitled.path, std::path::PathBuf::from("untitled:Untitled-1"));
+    assert_eq!(untitled.language.as_str(), "plaintext");
+    let version = ops::doc::edit(&host, "main", untitled.id, untitled.version, untitled_edit("# notes\n")).unwrap();
+    assert!(ops::doc::save(&host, "main", untitled.id).await.is_ok(), "saving nowhere is a no-op");
+    assert!(host.project("main").unwrap().documents.is_dirty(untitled.id).unwrap());
+
+    // Save As: the buffer lands on the disk and turns into a file document.
+    let target = dir.join("deep/notes.md");
+    let saved = ops::doc::save_as(&host, "main", untitled.id, target.clone()).await.unwrap();
+    assert_eq!(saved.path, target);
+    assert_eq!(saved.language.as_str(), "markdown");
+    assert!(!saved.dirty);
+    // The platform's default line separator applies to new buffers.
+    assert_eq!(std::fs::read_to_string(&target).unwrap().replace("\r\n", "\n"), "# notes\n");
+    ops::doc::edit(&host, "main", untitled.id, version, untitled_edit("x\n")).unwrap();
+    ops::doc::save(&host, "main", untitled.id).await.unwrap();
+    assert_eq!(std::fs::read_to_string(&target).unwrap().replace("\r\n", "\n"), "x\n# notes\n");
+
+    // The saved file's folder is followed for external changes now.
+    host.shutdown().await;
+}
+
+fn untitled_edit(insert: &str) -> ChangeSet {
+    ChangeSet { changes: vec![TextChange { from: 0, to: 0, insert: insert.into() }] }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn untitled_buffers_follow_the_window_into_a_project() {
+    let tmp = tempfile::tempdir().unwrap();
+    let tmp_root = dunce::canonicalize(tmp.path()).unwrap();
+    let host = host(&tmp_root.join("app"));
+
+    // A LightEdit window with an edited untitled buffer (and a clean one).
+    host.open_light_empty("main").unwrap();
+    let draft = ops::doc::open_untitled(&host, "main", None).await.unwrap();
+    ops::doc::edit(&host, "main", draft.id, draft.version, untitled_edit("{\"draft\": true}")).unwrap();
+    let clean = ops::doc::open_untitled(&host, "main", None).await.unwrap();
+
+    // The window switches to a project: the buffers follow, contents and dirty flags kept.
+    let project_root = tmp_root.join("proj");
+    std::fs::create_dir_all(&project_root).unwrap();
+    let project = host.open_project("main", &project_root).unwrap();
+    assert!(!project.light);
+
+    let carried =
+        ops::doc::open_untitled(&host, "main", Some(draft.path.to_string_lossy().into_owned())).await.unwrap();
+    assert_eq!(carried.path, draft.path, "same key, fresh registry: a new doc id carries the content");
+    let snap = ops::doc::snapshot(&host, "main", carried.id).await.unwrap();
+    assert_eq!(snap.text, "{\"draft\": true}");
+    assert!(host.project("main").unwrap().documents.is_dirty(carried.id).unwrap());
+    assert_eq!(snap.language.as_str(), "plaintext");
+
+    let clean_carried =
+        ops::doc::open_untitled(&host, "main", Some(clean.path.to_string_lossy().into_owned())).await.unwrap();
+    assert!(!host.project("main").unwrap().documents.is_dirty(clean_carried.id).unwrap());
+    host.shutdown().await;
+}
@@ -0,0 +1,141 @@
+//! The native `nav_inheritance` command: it must return every Python class definition
+//! in the project — attached dependency roots included — together with the base names
+//! written in its source, so the UI can compute inheritance gutter markers without a
+//! language server's type-hierarchy provider.
+
+use ide_host::{Host, HostConfig, ops};
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::{Duration, Instant};
+
+const WINDOW: &str = "main";
+
+struct Opened {
+    host: Arc<Host>,
+    root: PathBuf,
+    _tmp: tempfile::TempDir,
+}
+
+/// Opens a synthetic project whose Python files carry known class / base shapes, then
+/// waits for the index to settle (it walks content roots, so dependency roots are covered).
+async fn open() -> Opened {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = dunce::canonicalize(tmp.path()).unwrap().join("proj");
+    let src = root.join("src");
+    let dep = root.join("vendor");
+    std::fs::create_dir_all(&src).unwrap();
+    std::fs::create_dir_all(&dep).unwrap();
+
+    // Own root: a plain class, a class with two bases + a keyword arg, a qualified base,
+    // and a subscripted generic base. A comment / docstring that mentions `class X(Y)`
+    // must not be reported.
+    std::fs::write(
+        src.join("app.py"),
+        concat!(
+            "class Base:\n",
+            "    pass\n",
+            "\n",
+            "class Mixin:\n",
+            "    pass\n",
+            "\n",
+            "class Child(Base, Mixin, metaclass=Meta):\n",
+            "    # class Ghost(Spook): must be ignored\n",
+            "    \"\"\"class Phantom(Apparition): must be ignored\"\"\"\n",
+            "    pass\n",
+            "\n",
+            "class Qualified(pkg.mod.Base):\n",
+            "    pass\n",
+            "\n",
+            "class Generic(Generic[T]):\n",
+            "    pass\n",
+        ),
+    )
+    .unwrap();
+    // A second own-root file to prove the command scans more than one file.
+    std::fs::write(src.join("extra.pyi"), "class Stub(Base):\n    ...\n").unwrap();
+    // An attached dependency root (content root) — must be covered by the index.
+    std::fs::write(dep.join("dep.py"), "class DepBase:\n    pass\n").unwrap();
+
+    let app = tmp.path().join("app");
+    let host = Arc::new(Host::new(HostConfig {
+        config_dir: app.join("config"),
+        data_dir: app.join("data"),
+        local_data_dir: app.join("data"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new(|_| Arc::new(|_| {})),
+        owner: |w| w,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    }));
+    host.trust.decide(&root, true, false).unwrap();
+    ops::project::open(&host, WINDOW, &root).await.unwrap();
+
+    let deadline = Instant::now() + Duration::from_secs(30);
+    loop {
+        let s = ops::nav::index_status(&host, WINDOW).unwrap();
+        if !s.indexing && s.files > 0 {
+            break;
+        }
+        assert!(Instant::now() < deadline, "indexing timed out; status: {s:?}");
+        tokio::time::sleep(Duration::from_millis(100)).await;
+    }
+    Opened { host, root, _tmp: tmp }
+}
+
+fn find<'a>(all: &'a [ide_host::ops::nav::ClassInheritance], name: &str) -> &'a ide_host::ops::nav::ClassInheritance {
+    all.iter().find(|c| c.name == name).unwrap_or_else(|| panic!("no class {name:?} in {all:#?}"))
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn returns_all_python_classes_and_bases() {
+    let p = open().await;
+    let all = ops::nav::nav_inheritance(&p.host, WINDOW).await.unwrap();
+
+    // Both own-root Python files are scanned (src/app.py + src/extra.pyi).
+    let base = find(&all, "Base");
+    assert!(base.path.0.ends_with("src/app.py"), "Base path: {:?}", base.path);
+    // The location is the class name identifier (selection-range start), i.e. after `class `.
+    assert_eq!(base.line, 0);
+    assert_eq!(base.col, 6);
+    assert!(base.bases.is_empty(), "a bare class has no bases: {:?}", base.bases);
+
+    let child = find(&all, "Child");
+    assert_eq!(child.line, 6);
+    assert_eq!(child.col, 6);
+    // The `metaclass=Meta` keyword argument is not a base.
+    assert!(child.bases.contains(&"Base".to_string()), "Child bases: {:?}", child.bases);
+    assert!(child.bases.contains(&"Mixin".to_string()), "Child bases: {:?}", child.bases);
+    assert!(!child.bases.iter().any(|b| b == "Meta"), "metaclass must be skipped: {:?}", child.bases);
+
+    // A qualified base keeps only its last segment.
+    let qualified = find(&all, "Qualified");
+    assert_eq!(qualified.bases, vec!["Base".to_string()], "qualified base: {:?}", qualified.bases);
+
+    // A subscripted generic base keeps the identifier.
+    let generic = find(&all, "Generic");
+    assert_eq!(generic.bases, vec!["Generic".to_string()], "generic base: {:?}", generic.bases);
+
+    // Comments / docstrings are not mistaken for class definitions.
+    assert!(!all.iter().any(|c| c.name == "Ghost" || c.name == "Phantom"), "parsed a comment: {all:#?}");
+
+    // The .pyi stub in the second own-root file is included.
+    let stub = find(&all, "Stub");
+    assert!(stub.path.0.ends_with("src/extra.pyi"), "Stub path: {:?}", stub.path);
+    assert_eq!(stub.bases, vec!["Base".to_string()]);
+
+    // The attached dependency root is covered by the project index.
+    let dep = find(&all, "DepBase");
+    assert!(dep.path.0.starts_with(&p.root), "DepBase path: {:?}", dep.path);
+
+    // Every returned entry is a Python file.
+    assert!(all.iter().all(|c| { matches!(c.path.0.extension().and_then(|e| e.to_str()), Some("py" | "pyi")) }));
+
+    // A file changed on disk is parsed again; the others come from the cache.
+    let extra = p.root.join("src/extra.pyi");
+    std::fs::write(&extra, "class Stub(Child): ...\nclass Added(Base): ...\n").unwrap();
+    let again = ops::nav::nav_inheritance(&p.host, WINDOW).await.unwrap();
+    assert_eq!(find(&again, "Stub").bases, vec!["Child".to_string()]);
+    assert_eq!(find(&again, "Added").bases, vec!["Base".to_string()]);
+    assert_eq!(find(&again, "Child").bases, child.bases);
+}
@@ -99,6 +99,21 @@ async fn editor_ops_merge_the_fixture_format_selection_and_execute_owned_command
    let path = root.join("a.txt");
    std::fs::write(&path, "value\nnext\nend").unwrap();
    let doc = ops::doc::open(&host, "main", path.clone()).await.unwrap();
+    // `a.toml` has neither a language server, a completion plugin, nor an injection plugin, so `Unavailable` is preserved.
+    let toml_path = root.join("a.toml");
+    std::fs::write(&toml_path, "k = 1\n").unwrap();
+    let toml_doc = ops::doc::open(&host, "main", toml_path).await.unwrap();
+    assert_eq!(
+        ops::lsp::lsp_completion(&host, "main", RequestId(89), toml_doc.id, Pos::default(), None)
+            .await
+            .unwrap_err()
+            .kind,
+        ide_core::error::ErrorKind::Unavailable
+    );
+    let sql_path = root.join("q.sql");
+    std::fs::write(&sql_path, "SELECT 1;").unwrap();
+    let sql_doc = ops::doc::open(&host, "main", sql_path).await.unwrap();
+    assert!(ops::lsp::lsp_completion(&host, "main", RequestId(90), sql_doc.id, Pos::default(), None).await.is_ok());
    assert_eq!(
        ops::lsp::lsp_signature_help(&host, "main", doc.id, Pos::default()).await.unwrap().unwrap().signatures[0]
            .parameters,
@@ -821,8 +821,10 @@ fn a_reporting_task_outlives_its_background_budget() {

 #[test]
 fn background_tasks_scale_and_renew_cpu_fuel_budget() {
+    // Room for activation (about 3_100 on macOS, more on Windows) but not for `patient`'s
+    // whole run (about 9_000) without the refill on each report.
    let f = fixture(Limits {
-        fuel: 3_500,
+        fuel: 6_000,
        timeout: Duration::from_millis(500),
        background: Duration::from_millis(5_000),
        ..Limits::default()
@@ -831,14 +833,14 @@ fn background_tasks_scale_and_renew_cpu_fuel_budget() {
    if f.host.set_capability("misbehave", "process:git", true).is_err() {
        return;
    }
-    // Warm up activation in its own call so `patient` starts with a fresh 3_500-fuel budget.
+    // Warm up activation in its own call so `patient` starts with a fresh budget.
    assert_eq!(f.run("misbehave", "echo", Some("warm")).unwrap().as_deref(), Some("warm"));

    let out = f.run("misbehave", "patient", None).expect("background task succeeds").expect("output");
    assert_eq!(out, "still here");

    let err = f.run("misbehave", "spin", None).unwrap_err();
-    assert!(err.contains("exceeded its CPU budget (3500 fuel per call)"), "{err}");
+    assert!(err.contains("exceeded its CPU budget (6000 fuel per call)"), "{err}");
 }

 #[test]
@@ -3760,6 +3762,43 @@ path = "templates/new.draw"
    assert!(f.host.web_page("web-demo", "draw").is_err());
 }

+#[test]
+fn file_icons_without_patterns_require_api_1_8_and_project_assets() {
+    let f = fixture(Limits::default());
+    let tmp = tempfile::tempdir().unwrap();
+    let pkg = tmp.path().join("dynamic-icons");
+    std::fs::create_dir_all(pkg.join("icons")).unwrap();
+    std::fs::write(pkg.join("icons/helm-dir.svg"), r#"<svg viewBox="0 0 16 16"><circle cx="8" cy="8" r="6"/></svg>"#)
+        .unwrap();
+    let write_manifest = |api: &str| {
+        std::fs::write(
+            pkg.join("plugin.toml"),
+            format!(
+                r#"id = "dynamic-icons"
+name = "Dynamic Icons"
+version = "0.1.0"
+engines.openidea = "{api}"
+
+[[contributes.fileIcons]]
+id = "helm-dir"
+icon = "icons/helm-dir.svg"
+"#
+            ),
+        )
+        .unwrap();
+    };
+    write_manifest("^1.7");
+    let err = f.host.install_from_dir(&pkg, &Consent::all()).unwrap_err();
+    assert!(err.message.contains("1.8"), "{err:?}");
+
+    write_manifest("^1.8");
+    let info = f.install(&pkg);
+    assert!(info.error.is_none(), "{:?}", info.error);
+    let assets = f.host.assets("dynamic-icons", "fileIcon/helm-dir/").unwrap();
+    assert_eq!(assets.len(), 1);
+    assert!(assets[0].1.contains("<circle"));
+}
+
 #[test]
 fn file_templates_fixture_installs_without_write_capabilities() {
    let f = fixture(Limits::default());
@@ -367,6 +367,7 @@ async fn remote_projects_get_plugin_views_and_custom_editors() {

 #[tokio::test(flavor = "multi_thread", worker_threads = 4)]
 async fn api14_remote_calls_keep_browser_listeners_and_secrets_on_the_desktop() {
+    use ide_core::{Diagnostic, Pos, Range, Severity};
    use tokio::io::{AsyncReadExt, AsyncWriteExt};
    let tmp = tempfile::tempdir().unwrap();
    let desktop = Arc::new(
@@ -426,42 +427,70 @@ async fn api14_remote_calls_keep_browser_listeners_and_secrets_on_the_desktop()
            "severity": "warning", "message": message, "source": "remote-check", "code": null
        }]})
    };
+    let publish = |path: &Path, source: &str, message: Option<&str>| {
+        let items = message
+            .map(|message| Diagnostic {
+                range: Range::new(Pos::new(0, 1), Pos::new(0, 3)),
+                severity: Severity::Warning,
+                message: message.into(),
+                source: Some(source.into()),
+                code: None,
+                unnecessary: false,
+                deprecated: false,
+                server: None,
+            })
+            .into_iter()
+            .collect();
+        host.project("main").unwrap().sink.emit(IdeEvent::Diagnostics {
+            path: path.to_path_buf().into(),
+            source: source.into(),
+            items,
+        });
+    };
    let files = json!([
        problem(&remote_file, "remote warning"),
        problem(&other_file, "other warning"),
        problem(&outside_file, "outside warning")
    ]);
    invoke(&peer, "mcp_report_problems", json!({"reset": true, "files": files})).await.unwrap();
+    // UI reports are not the source of the plugin's host-owned snapshot.
+    assert_eq!(invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap(), json!("[]"));
+    publish(&remote_file, "remote-check", Some("remote warning"));
+    publish(&other_file, "remote-check", Some("other warning"));
+    publish(&outside_file, "remote-check", Some("outside warning"));
+
    let problems = invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap();
    let problems = problems.as_str().unwrap();
    assert!(problems.contains("remote warning"), "{problems}");
    assert!(problems.contains("other warning"), "{problems}");
-    assert!(!problems.contains("outside warning"), "{problems}");
+    assert!(problems.contains("outside warning"), "{problems}");
    for path in ["remote.txt", remote_file.to_str().unwrap()] {
        let problems = invoke(&peer, "plugin_run_command", run("problems", Some(path))).await.unwrap();
        let problems = problems.as_str().unwrap();
        assert!(problems.contains("remote warning"), "{problems}");
        assert!(!problems.contains("other warning"), "{problems}");
+        assert!(!problems.contains("outside warning"), "{problems}");
        assert!(problems.contains(remote_file.to_str().unwrap()), "{problems}");
    }
    assert_eq!(invoke(&peer, "plugin_run_command", run("problems", Some("missing.txt"))).await.unwrap(), json!("[]"));
-    invoke(&peer, "mcp_report_problems", json!({"reset": false, "files": [{"path": remote_file, "items": []}]}))
-        .await
-        .unwrap();
+    publish(&remote_file, "second-check", Some("second warning"));
+    invoke(&peer, "mcp_report_problems", json!({"reset": true, "files": []})).await.unwrap();
+    let problems = invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap();
+    assert!(problems.as_str().unwrap().contains("remote warning"));
+    assert!(problems.as_str().unwrap().contains("second warning"));
+    publish(&remote_file, "remote-check", None);
    let problems = invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap();
    assert!(!problems.as_str().unwrap().contains("remote warning"));
+    assert!(problems.as_str().unwrap().contains("second warning"));
    assert!(problems.as_str().unwrap().contains("other warning"));
-    invoke(
-        &peer,
-        "mcp_report_problems",
-        json!({"reset": true, "files": [problem(&remote_file, "replacement warning")]}),
-    )
-    .await
-    .unwrap();
+    publish(&remote_file, "second-check", Some("replacement warning"));
    let problems = invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap();
    assert!(problems.as_str().unwrap().contains("replacement warning"));
-    assert!(!problems.as_str().unwrap().contains("other warning"));
-    invoke(&peer, "mcp_report_problems", json!({"reset": true, "files": []})).await.unwrap();
+    assert!(!problems.as_str().unwrap().contains("second warning"));
+    assert!(problems.as_str().unwrap().contains("other warning"));
+    publish(&remote_file, "second-check", None);
+    publish(&other_file, "remote-check", None);
+    publish(&outside_file, "remote-check", None);
    assert_eq!(invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap(), json!("[]"));
    invoke(&peer, "plugin_run_command", run("open-editor", Some("remote.txt"))).await.unwrap();
    invoke(&peer, "plugin_run_command", run("decorations", remote_file.to_str())).await.unwrap();
@@ -513,11 +542,11 @@ async fn api14_remote_calls_keep_browser_listeners_and_secrets_on_the_desktop()
    stream.read_to_string(&mut response).await.unwrap();
    assert!(response.contains("You can close this tab"));
    assert_eq!(oauth.await.unwrap().unwrap(), json!("code=desktop%2Bcode"));
-    invoke(&peer, "mcp_report_problems", json!({"reset": true, "files": files})).await.unwrap();
+    publish(&remote_file, "remote-check", Some("remote warning"));
    invoke(&peer, "close_project", json!({})).await.unwrap();
    invoke(&peer, "open_project", json!({"path": project})).await.unwrap();
    assert_eq!(invoke(&peer, "plugin_run_command", run("problems", None)).await.unwrap(), json!("[]"));
-    invoke(&peer, "mcp_report_problems", json!({"reset": true, "files": files})).await.unwrap();
+    publish(&remote_file, "remote-check", Some("remote warning"));
    peer.kill();
    tokio::time::timeout(Duration::from_secs(5), server).await.unwrap().unwrap();
    let plugin_host = plugins.host().clone();
@@ -537,7 +566,11 @@ async fn api14_remote_calls_keep_browser_listeners_and_secrets_on_the_desktop()
    })
    .await
    .unwrap();
-    assert_eq!(result.as_deref(), Some("[]"));
+    // Disconnect clears desktop reports, not the still-live host project snapshot.
+    let problems = result.as_deref().unwrap();
+    assert!(problems.contains("remote warning"), "{problems}");
+    assert!(problems.contains("remote-check"), "{problems}");
+    assert!(problems.contains(remote_file.to_str().unwrap()), "{problems}");
    plugins.host().shutdown();
    desktop.shutdown();
 }
@@ -82,7 +82,9 @@ async fn serves_projects_files_documents_search_and_runs() {
    invoke(&peer, "lsp_resend_diagnostics", json!({})).await.unwrap();
    let files = invoke(&peer, "find_files", json!({"query": "main", "limit": 10})).await.unwrap();
    assert!(files.is_array());
-    for command in ["build_sync", "run_start", "sdk_locate_tools", "notebook_execute", "debug_start"] {
+    for command in
+        ["build_sync", "run_start", "sdk_locate_tools", "notebook_execute", "debug_start", "agent_refresh_models"]
+    {
        let error = invoke(&peer, command, json!({})).await.unwrap_err();
        assert!(error.message.contains("Restricted Mode"), "{command}: {error:?}");
    }
@@ -341,6 +343,7 @@ async fn local_deployment_runs_on_the_project_host() {
        "db_save_sources",
        "db_set_password",
        "db_test",
+        "db_test_tunnel",
        "db_set_ssh_secret",
        "db_trust_ssh_host",
        "db_connected",
@@ -364,6 +367,14 @@ async fn local_deployment_runs_on_the_project_host() {
        "db_table_page",
        "db_apply_edits",
        "db_console_path",
+        "db_consoles",
+        "ssh_test",
+        "ssh_set_secret",
+        "ssh_password_saved",
+        "ssh_needs_secret",
+        "ssh_trust_host",
+        "ssh_connected",
+        "ssh_disconnect",
    ] {
        assert!(dispatcher.commands().contains(&cmd), "missing host command {cmd}");
    }
@@ -372,6 +383,12 @@ async fn local_deployment_runs_on_the_project_host() {
    tokio::spawn(rpc::serve(host, dispatcher, slot, sr, sw));
    let (cr, cw) = tokio::io::split(client_io);
    let peer = Peer::connect(cr, cw, Arc::new(Client::default()));
+    // A remote window's host-key and password remedies reach the server's SSH manager,
+    // the one its deployment / database connections failed in.
+    let trust = invoke(&peer, "ssh_trust_host", json!({"id": "nothing-pending"})).await.unwrap_err();
+    assert!(trust.message.contains("no host key to trust"), "{trust:?}");
+    invoke(&peer, "ssh_set_secret", json!({"id": "deploy", "secret": "pw", "save": false})).await.unwrap();
+    assert_eq!(invoke(&peer, "ssh_connected", json!({})).await.unwrap(), json!([]));
    invoke(&peer, "project_trust_set", json!({"path": project, "trusted": true, "folder": false})).await.unwrap();
    invoke(&peer, "open_project", json!({"path": project})).await.unwrap();
    let deployment = json!({"servers": [{"id":"local", "kind":"local", "rootPath":target}], "defaultServer":"local"});
@@ -66,6 +66,7 @@ async fn application_commands_work_in_restricted_projects_and_without_a_project(
        "docker_set_registry_password",
        "docker_run_env",
        "db_console_path",
+        "db_consoles",
        "db_export_file",
        "vcs_write_patch",
        "remote_bootstrap_list",
@@ -92,6 +93,7 @@ async fn application_commands_work_in_restricted_projects_and_without_a_project(
        "vcs_git_version",
        "docker_compose_op",
        "db_execute",
+        "agent_refresh_models",
        "remote_delete",
        "remote_mkdir",
        "remote_rename",
@@ -172,6 +172,7 @@ async fn restricted_vcs_commands_run_no_program_of_the_repository() {
    }
    let calls: Vec<Call> = vec![
        call!("vcs_status", "", ops::vcs::status(host, w)),
+        call!("vcs_status_paths", "", ops::vcs::status_paths(host, w, vec![file.clone()])),
        sync!("vcs_roots", "", vcs::vcs_roots(host, w)),
        call!("vcs_branch_info", "", vcs::vcs_branch_info(host, w, root())),
        call!("vcs_line_hunks", "", vcs::vcs_line_hunks(host, w, file.clone())),
@@ -102,7 +102,7 @@ async fn stash_and_unstash_reload_clean_open_documents_before_returning() {
    let f = Fixture::new().await;
    let edited = format!("{ORIGINAL}\n");
    f.saved_edit(&edited);
-    vcs::vcs_stash_push(&f.host, "main", None, None, false, false).await.unwrap();
+    vcs::vcs_stash_push(&f.host, "main", None, None, false, false, None).await.unwrap();
    f.assert_clean(ORIGINAL);
    vcs::vcs_stash_apply(&f.host, "main", None, 0, true, false, None).await.unwrap();
    f.assert_clean(&edited);
@@ -168,7 +168,7 @@ async fn change_commit_branch_stash_and_merge_a_conflict() {
    let wip = format!("{}// work in progress\n", f.text(main_rs).await);
    f.host.project(WINDOW).unwrap().documents.replace_all(main_rs, &wip).unwrap();
    f.save(main_rs).await;
-    ops::vcs::vcs_stash_push(&f.host, WINDOW, None, Some("wip".into()), false, false).await.unwrap();
+    ops::vcs::vcs_stash_push(&f.host, WINDOW, None, Some("wip".into()), false, false, None).await.unwrap();
    assert!(f.status().await.is_empty());
    assert!(!f.text(main_rs).await.contains("work in progress"));
    let stashes = ops::vcs::vcs_stashes(&f.host, WINDOW, None).await.unwrap();
@@ -0,0 +1,54 @@
+//! A repository folder moved into an open project is registered while the project is open:
+//! the folder brings no `.git` event of its own, so the watcher's "created path" is what the
+//! rescan has to answer to (the open scan already ran).
+
+use ide_core::NullSink;
+use ide_host::{Host, HostConfig};
+use std::{path::Path, sync::Arc, time::Duration};
+
+fn git_init(dir: &Path) {
+    std::fs::create_dir_all(dir).unwrap();
+    let status = std::process::Command::new("git").args(["init", "-q"]).current_dir(dir).status();
+    assert!(status.is_ok_and(|status| status.success()), "git init in {}", dir.display());
+}
+
+async fn wait_until(what: &str, mut done: impl FnMut() -> bool) {
+    let deadline = tokio::time::Instant::now() + Duration::from_secs(15);
+    while !done() {
+        assert!(tokio::time::Instant::now() < deadline, "timed out waiting for {what}");
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+}
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn moving_a_repository_into_the_project_registers_it() {
+    let temp = tempfile::tempdir().unwrap();
+    let base = dunce::canonicalize(temp.path()).unwrap();
+    let root = base.join("project");
+    git_init(&root);
+    // Prepared outside the project, as a restored or moved folder would be.
+    let prepared = base.join("prepared");
+    git_init(&prepared);
+
+    let host = Host::new(HostConfig {
+        config_dir: base.join("config"),
+        data_dir: base.join("data"),
+        local_data_dir: base.join("data"),
+        languages: Arc::new(ide_language::LanguageRegistry::load(None).unwrap()),
+        syntax: Arc::default(),
+        sink_for: Box::new(|_| Arc::new(NullSink)),
+        owner: |w| w,
+        runtime: tokio::runtime::Handle::current(),
+        project_environment: false,
+    });
+    host.trust.decide(&root, true, false).unwrap();
+    let project = host.open_project("main", &root).unwrap();
+    // The scan on project open runs in the background: wait for it before moving anything in.
+    wait_until("the project's own repository", || project.repos().roots().len() == 1).await;
+
+    std::fs::rename(&prepared, root.join("moved")).unwrap();
+    wait_until("the moved repository to be registered", || {
+        project.repos().roots().iter().any(|r| r.ends_with("moved"))
+    })
+    .await;
+}
@@ -9,7 +9,7 @@ license.workspace = true
 ide-core.workspace = true
 ide-vfs.workspace = true
 serde.workspace = true
-serde_json.workspace = true
+serde_json = { workspace = true, features = ["raw_value"] }
 specta.workspace = true
 tokio.workspace = true
 tracing.workspace = true
@@ -52,26 +52,35 @@ fn search_dirs(file: Option<&Path>, root: Option<&Path>) -> Vec<PathBuf> {
 }

 fn parse_env(text: &str) -> IdeResult<EnvMap> {
+    use serde_json::value::RawValue;
+
+    let invalid = |e| IdeError::invalid(format!("invalid environment file: {e}"));
    // Editors on Windows (Notepad) save UTF-8 with a byte order mark, which serde_json rejects.
    let text = text.strip_prefix('\u{feff}').unwrap_or(text);
-    let value: serde_json::Value =
-        serde_json::from_str(text).map_err(|e| IdeError::invalid(format!("invalid environment file: {e}")))?;
+    let value: Box<RawValue> = serde_json::from_str(text).map_err(invalid)?;
    let mut out = EnvMap::new();
-    let Some(envs) = value.as_object() else { return Ok(out) };
+    if !value.get().starts_with('{') {
+        return Ok(out);
+    }
+    let envs: BTreeMap<String, Box<RawValue>> = serde_json::from_str(value.get()).map_err(invalid)?;
    for (env, vars) in envs {
-        let Some(vars) = vars.as_object() else { continue };
+        if !vars.get().starts_with('{') {
+            continue;
+        }
+        let vars: BTreeMap<String, Box<RawValue>> = serde_json::from_str(vars.get()).map_err(invalid)?;
        let mut map = BTreeMap::new();
        for (k, v) in vars {
-            let s = match v {
-                serde_json::Value::String(s) => s.clone(),
-                serde_json::Value::Number(n) => n.to_string(),
-                serde_json::Value::Bool(b) => b.to_string(),
+            let raw = v.get();
+            let s = match raw.as_bytes().first() {
+                Some(b'"') => serde_json::from_str::<String>(raw).map_err(invalid)?,
+                // Keep numeric tokens: Value::Number would round decimals and large integers.
+                Some(b'-' | b'0'..=b'9' | b't' | b'f') => raw.to_owned(),
                // Objects configure SSL / auth in IDEA; not variables.
                _ => continue,
            };
-            map.insert(k.clone(), s);
+            map.insert(k, s);
        }
-        out.insert(env.clone(), map);
+        out.insert(env, map);
    }
    Ok(out)
 }
@@ -304,6 +313,85 @@ impl Resolver<'_> {
 mod tests {
    use super::*;

+    #[test]
+    fn preserves_exact_numeric_environment_tokens() {
+        for token in [
+            "0",
+            "-0",
+            "0.0",
+            "-0.000",
+            "1",
+            "-1",
+            "9007199254740991",
+            "9007199254740992",
+            "9007199254740993",
+            "9223372036854775807",
+            "-9223372036854775808",
+            "18446744073709551615",
+            "18446744073709551616",
+            "123456789012345678901234567890",
+            "-123456789012345678901234567890",
+            "1.0000000000000000002",
+            "-1.0000000000000000002",
+            "0.12345678901234567890123456789",
+            "-0.0000000000000000000000000001",
+            "1e-400",
+            "-1e-400",
+            "1e400",
+            "-1e400",
+            "1.2300e+20",
+            "1.2300E+020",
+        ] {
+            let json = format!(r#"{{"dev":{{"value":{token}}}}}"#);
+            let envs = Environments::from_json(&json, "").unwrap();
+            let vars = envs.variables(Some("dev"));
+            assert_eq!(vars["value"], token);
+            let resolver = Resolver { file_vars: &[], env: vars };
+            let mut missing = BTreeSet::new();
+            assert_eq!(resolver.substitute("{\"value\":{{value}}}", &mut missing), format!(r#"{{"value":{token}}}"#));
+            assert!(missing.is_empty());
+        }
+    }
+
+    #[test]
+    fn rejects_malformed_numeric_environment_tokens() {
+        for token in ["01", "+1", "1.", ".1", "NaN", "Infinity", "--1", "1e", "1e+", "1e--2", "0xFF"] {
+            let json = format!(r#"{{"dev":{{"value":{token}}}}}"#);
+            assert!(Environments::from_json(&json, "").is_err(), "accepted {token}");
+        }
+        assert!(Environments::from_json(r#"{"dev":{"ssl":{"invalid":01}}}"#, "").is_err());
+    }
+
+    #[test]
+    fn reads_numeric_tokens_with_whitespace_and_escaped_names() {
+        let envs = Environments::from_json(
+            "\u{feff} \n { \"de\\u0076\": \n {\"va\\u006cue\": \t 1.2300E+020, \"value\": 1.0000000000000000002 }} \n",
+            "",
+        )
+        .unwrap();
+        assert_eq!(envs.names(), vec!["dev"]);
+        assert_eq!(envs.variables(Some("dev"))["value"], "1.0000000000000000002");
+    }
+
+    #[test]
+    fn exact_environment_parsing_keeps_types_and_precedence() {
+        let envs = Environments::from_json(
+            r#"{"$shared":{"shared":1.0000000000000000002},"dev":{"v":1,"v":9007199254740993,"enabled":true,"disabled":false,"s":"a\n\"b","null":null,"ssl":{},"arr":[]},"other":42}"#,
+            r#"{"dev":{"v":9223372036854775807}}"#,
+        ).unwrap();
+        let vars = envs.variables(Some("dev"));
+        assert_eq!(vars["v"], "9223372036854775807");
+        assert_eq!(vars["shared"], "1.0000000000000000002");
+        assert_eq!(vars["enabled"], "true");
+        assert_eq!(vars["disabled"], "false");
+        assert_eq!(vars["s"], "a\n\"b");
+        assert!(!vars.contains_key("null"));
+        assert!(!vars.contains_key("ssl"));
+        assert!(!vars.contains_key("arr"));
+        assert_eq!(Environments::from_json("[]", "").unwrap().names(), Vec::<String>::new());
+        assert!(Environments::from_json(r#"{"dev":{"v":01}}"#, "").is_err());
+    }
+
    #[test]
    fn finds_variable_keys_in_every_environment_private_first() {
        let tmp = tempfile::tempdir().unwrap();
@@ -249,6 +249,68 @@ mod tests {
        assert_eq!(url("GET https://api.test/cb?u=http://x\n"), "https://api.test/cb?u=http://x");
    }

+    #[tokio::test]
+    async fn sends_exact_environment_numbers_to_a_local_server() {
+        use tokio::io::{AsyncReadExt, AsyncWriteExt};
+        let listener = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
+        let addr = listener.local_addr().unwrap();
+        let server = tokio::spawn(async move {
+            let (mut socket, _) = listener.accept().await.unwrap();
+            let mut request = Vec::new();
+            let (headers, body) = loop {
+                let mut buffer = [0u8; 4096];
+                let read = socket.read(&mut buffer).await.unwrap();
+                assert!(read > 0, "request ended before its body");
+                request.extend_from_slice(&buffer[..read]);
+                let Some(end) = request.windows(4).position(|w| w == b"\r\n\r\n") else { continue };
+                let headers = String::from_utf8_lossy(&request[..end]);
+                let length: usize = headers
+                    .lines()
+                    .find_map(|line| {
+                        let (name, value) = line.split_once(':')?;
+                        name.eq_ignore_ascii_case("content-length").then(|| value.trim().parse().unwrap())
+                    })
+                    .unwrap();
+                if request.len() >= end + 4 + length {
+                    break (
+                        String::from_utf8(request[..end].to_vec()).unwrap(),
+                        String::from_utf8(request[end + 4..end + 4 + length].to_vec()).unwrap(),
+                    );
+                }
+            };
+            let response = format!(
+                "HTTP/1.1 200 OK\r\nContent-Type: application/json\r\nContent-Length: {}\r\n\r\n{body}",
+                body.len()
+            );
+            socket.write_all(response.as_bytes()).await.unwrap();
+            (headers, body)
+        });
+        let tmp = tempfile::tempdir().unwrap();
+        std::fs::write(
+            tmp.path().join(crate::env::PUBLIC_FILE),
+            r#"{"dev":{"id":123456789012345678901234567890,"amount":1.0000000000000000002,"tiny":1e-400}}"#,
+        )
+        .unwrap();
+        let file = tmp.path().join("precision.http");
+        let text = format!(
+            "POST http://{addr}/echo?id={{{{id}}}}\nContent-Type: application/json\nX-Exact-Amount: {{{{amount}}}}\n\n{{\"id\":{{{{id}}}},\"amount\":{{{{amount}}}},\"tiny\":{{{{tiny}}}}}}\n"
+        );
+        let input =
+            crate::RunInput { text: &text, index: 0, file: Some(&file), root: Some(tmp.path()), env: Some("dev") };
+        let exchange =
+            tokio::time::timeout(std::time::Duration::from_secs(5), crate::run(input, &CancellationToken::new()))
+                .await
+                .unwrap()
+                .unwrap();
+        let expected = r#"{"id":123456789012345678901234567890,"amount":1.0000000000000000002,"tiny":1e-400}"#;
+        let (headers, body) = server.await.unwrap();
+        assert_eq!(headers.lines().next().unwrap(), "POST /echo?id=123456789012345678901234567890 HTTP/1.1");
+        assert!(headers.lines().any(|line| line.eq_ignore_ascii_case("x-exact-amount: 1.0000000000000000002")));
+        assert_eq!(body, expected);
+        assert_eq!(exchange.request.body.as_deref(), Some(expected));
+        assert_eq!(exchange.response.unwrap().body.as_deref(), Some(expected));
+    }
+
    #[tokio::test]
    async fn executes_against_a_local_server() {
        use tokio::io::{AsyncReadExt, AsyncWriteExt};
@@ -31,3 +31,7 @@ criterion = { version = "0.5", default-features = false }
 [[bench]]
 name = "index"
 harness = false
+
+[[bench]]
+name = "startup"
+harness = false
@@ -0,0 +1,64 @@
+//! `cargo bench -p ide-index --bench startup`: open a persisted 20k-file
+//! project and wait for the index to become idle. This is the full warm-start
+//! path (columnar snapshot, directory/file manifest, lazy redb).
+
+use criterion::{Criterion, black_box, criterion_group, criterion_main};
+use ide_core::NullSink;
+use ide_index::ProjectIndex;
+use ide_language::{LanguageRegistry, Syntax};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use std::time::Duration;
+
+const FILES: usize = 20_000;
+
+fn project(root: &Path) {
+    for i in 0..FILES {
+        let dir = root.join(format!("mod{}/src", i % 50));
+        std::fs::create_dir_all(&dir).unwrap();
+        std::fs::write(dir.join(format!("File{i}.rs")), format!("fn symbol{i}() {{}}\n")).unwrap();
+    }
+}
+
+fn bench(c: &mut Criterion) {
+    let tmp = tempfile::tempdir().unwrap();
+    let root = tmp.path().join("project");
+    let cache = tmp.path().join("cache");
+    project(&root);
+
+    let languages = Arc::new(LanguageRegistry::load(None).unwrap());
+    let syntax = Arc::new(Syntax::new());
+    let open = || {
+        ProjectIndex::open(
+            &root,
+            &cache,
+            Vec::<PathBuf>::new(),
+            vec![],
+            languages.clone(),
+            syntax.clone(),
+            Arc::new(NullSink),
+        )
+        .unwrap()
+    };
+    let first = open();
+    assert!(first.wait_idle(Duration::from_secs(30)));
+    drop(first);
+
+    let mut group = c.benchmark_group("startup_20k");
+    group.sample_size(10);
+    group.bench_function("reopen_wait_idle", |b| {
+        b.iter(|| {
+            let index = open();
+            assert!(index.wait_idle(Duration::from_secs(30)));
+            black_box(index.status().files)
+        })
+    });
+    group.finish();
+}
+
+criterion_group! {
+    name = benches;
+    config = Criterion::default().measurement_time(Duration::from_secs(3));
+    targets = bench
+}
+criterion_main!(benches);
@@ -24,6 +24,19 @@ pub(crate) fn char_mask(s: &str) -> u64 {
    m
 }

+/// A relative index key must stay below the project root.
+pub(crate) fn safe_rel(rel: &str) -> bool {
+    let mut any = false;
+    for component in Path::new(rel).components() {
+        if matches!(component, std::path::Component::Normal(_)) {
+            any = true;
+        } else {
+            return false;
+        }
+    }
+    any
+}
+
 #[inline]
 pub(crate) fn mask_bit(b: u8) -> u64 {
    match b.to_ascii_lowercase() {
@@ -553,6 +566,67 @@ impl IndexData {
        self.by_path.get(path).copied()
    }

+    /// Reserves the flat tables for a bulk warm-start hydration.
+    pub(crate) fn reserve(&mut self, files: usize, symbols: usize, dirs: usize) {
+        self.files.reserve(files);
+        self.by_path.reserve(files);
+        self.dirs.reserve(dirs);
+        self.hot.rows.reserve(files);
+        self.dirs_hot.rows.reserve(dirs);
+        self.syms.head.reserve(symbols);
+        self.syms.container.reserve(symbols);
+        self.syms.kind.reserve(symbols);
+        self.syms.range.reserve(symbols);
+    }
+
+    /// Hydrates a validated warm-start snapshot in one pass, without per-file
+    /// duplicate checks, ancestor walks or compaction checks.
+    pub(crate) fn load_bulk(
+        &mut self,
+        entries: Vec<(FileEntry, Vec<StoredSymbol>)>,
+        dirs: Vec<(Box<str>, PathBuf, u32)>,
+    ) {
+        self.files = Vec::with_capacity(entries.len());
+        self.by_path = HashMap::with_capacity(entries.len());
+        self.hot = HotFiles::default();
+        self.dirs_hot = HotDirs::default();
+        self.syms = SymTable::default();
+        self.dirs = HashMap::with_capacity(dirs.len());
+        let symbols: usize = entries.iter().map(|(_, symbols)| symbols.len()).sum();
+        self.reserve(entries.len(), symbols, dirs.len());
+        self.symbol_count = 0;
+        for (slot, (mut entry, symbols)) in entries.into_iter().enumerate() {
+            let (sym_start, sym_mask) = self.syms.push(&symbols);
+            entry.sym_start = sym_start;
+            entry.sym_len = symbols.len() as u32;
+            self.symbol_count += entry.sym_len;
+            let rel = self.hot.append(&entry.rel);
+            self.hot.set(
+                slot as u32,
+                FileRow {
+                    rel,
+                    name_start: entry.name_start,
+                    sym_start,
+                    sym_len: entry.sym_len,
+                    sym_mask,
+                    rel_mask: entry.rel_mask,
+                    name_mask: entry.name_mask,
+                    dir_mask: char_mask(entry.dir()),
+                    ascii: entry.rel.is_ascii(),
+                    live: true,
+                },
+            );
+            self.by_path.insert(entry.path.clone(), slot as u32);
+            self.files.push(Some(entry));
+        }
+        self.file_count = self.files.len() as u32;
+        for (rel, path, count) in dirs {
+            let row = self.dirs_hot.push(&rel, &path);
+            self.dirs.insert(rel, (path, count, row));
+        }
+        self.free.clear();
+    }
+
    /// The persisted form of a file, rebuilt from [`IndexData::syms`].
    pub(crate) fn record(&self, e: &FileEntry) -> FileRecord {
        FileRecord {
@@ -793,6 +867,23 @@ mod tests {
        assert_eq!(d.symbol_count, d.files.iter().flatten().map(|e| e.sym_len).sum::<u32>());
    }

+    #[test]
+    fn bulk_load_matches_incremental_insert() {
+        let mut incremental = IndexData::default();
+        insert(&mut incremental, "a/b.rs", 2);
+        insert(&mut incremental, "c.rs", 1);
+        assert_consistent(&incremental);
+
+        let mut bulk = IndexData::default();
+        bulk.load_bulk(vec![entry("a/b.rs", 2), entry("c.rs", 1)], vec![("a/".into(), PathBuf::from("/r/a"), 1)]);
+        assert_consistent(&bulk);
+        assert_eq!((bulk.file_count, bulk.symbol_count), (2, 3));
+        assert_eq!(bulk.hot.text(), incremental.hot.text());
+        assert_eq!(bulk.files.len(), incremental.files.len());
+        assert_eq!(bulk.slot(Path::new("/r/a/b.rs")), incremental.slot(Path::new("/r/a/b.rs")));
+        assert_eq!(bulk.dirs["a/"].1, 1);
+    }
+
    #[test]
    fn dirs_follow_inserts_and_removals() {
        let mut d = IndexData::default();
@@ -138,6 +138,22 @@ impl PathFilter {
        &self.config.0 == extra_roots && self.config.1 == excludes
    }

+    /// Stable fingerprint of the persisted-scope configuration; a start-up
+    /// snapshot is only trusted when this still matches.
+    pub(crate) fn stamp(&self) -> String {
+        let mut stamp = format!("include_root={}\n", self.config.0.include_root);
+        for folder in &self.config.0.folders {
+            stamp.push_str(&folder.to_string_lossy());
+            stamp.push('\n');
+        }
+        stamp.push_str("--\n");
+        for exclude in &self.config.1 {
+            stamp.push_str(exclude);
+            stamp.push('\n');
+        }
+        stamp
+    }
+
    pub(crate) fn reload(&self) -> Self {
        Self::new(&self.root, &self.config.0, &self.config.1)
    }
@@ -146,6 +162,11 @@ impl PathFilter {
        &self.root
    }

+    /// Whether content roots outside the project root are indexed with it.
+    pub(crate) fn has_extra_roots(&self) -> bool {
+        !self.extra.is_empty()
+    }
+
    /// The project root, then the extra content roots.
    pub(crate) fn roots(&self) -> impl Iterator<Item = &Path> {
        std::iter::once(self.root.as_path())
@@ -227,6 +248,30 @@ impl PathFilter {
        dir.is_some_and(|d| gitignore.matched_path_or_any_parents(d, true).is_ignore())
    }

+    /// All directories at or below `dir` that the index would walk, in walk order.
+    pub(crate) fn dirs(&self, dir: &Path) -> Vec<PathBuf> {
+        let Some((root, _, _)) = self.base_of(dir) else { return Vec::new() };
+        let root = root.to_path_buf();
+        let excludes = self.excludes.clone();
+        let walk_root = root.clone();
+        let walk_excludes = excludes.clone();
+        let walker = WalkBuilder::new(dir)
+            .hidden(false)
+            .parents(true)
+            .ignore(true)
+            .git_ignore(true)
+            .git_global(true)
+            .git_exclude(true)
+            .require_git(ide_core::ignored::inside_git_repo(dir))
+            .follow_links(false)
+            .filter_entry(move |e| {
+                let name = e.file_name().to_string_lossy();
+                !Self::skip_name(&name) && !glob_excluded(&walk_excludes, &walk_root, e.path())
+            })
+            .build();
+        walker.flatten().filter(|e| e.file_type().is_some_and(|t| t.is_dir())).map(|e| e.into_path()).collect()
+    }
+
    /// All indexable files at or below `dir`, walked in parallel.
    /// Stops early (returning what was found so far) once `cancel` is set.
    pub(crate) fn walk(&self, dir: &Path, cancel: &AtomicBool) -> Vec<Found> {
@@ -1,75 +1,429 @@
 //! Persistence of file records in redb, so a restart only re-parses changed files.

-use crate::data::FileRecord;
+use crate::data::{FileEntry, FileRecord, IndexData, StoredSymbol};
+use crate::filter::{PathFilter, mtime_of};
+use ide_core::{Range, SymbolKind};
 use parking_lot::RwLock;
 use redb::{Database, Durability, ReadableDatabase, ReadableTable, TableDefinition, TableError};
+use serde::{Deserialize, Serialize};
 use std::path::Path;
+use std::time::{SystemTime, UNIX_EPOCH};

 const FILES: TableDefinition<&str, &[u8]> = TableDefinition::new("files");
 const META: TableDefinition<&str, &[u8]> = TableDefinition::new("meta");
 /// Bump when [`FileRecord`] or its encoding changes.
 const SCHEMA: &str = "openidea-index-3";

+/// The real Git directory for a checkout/worktree (`root/.git` may be a file
+/// containing `gitdir: ...`).
+fn git_dir(root: &Path) -> Option<std::path::PathBuf> {
+    let dot_git = root.join(".git");
+    if dot_git.is_dir() {
+        return Some(dot_git);
+    }
+    let text = std::fs::read_to_string(&dot_git).ok()?;
+    let target = text.strip_prefix("gitdir:")?.trim();
+    let path = Path::new(target);
+    Some(if path.is_absolute() { path.to_owned() } else { root.join(path) })
+}
+
+/// The config and exclude file of the Git directory `git`; a linked worktree's directory
+/// (`.git/worktrees/<name>`) reads the shared ones its `commondir` names as well.
+fn insert_git_inputs(out: &mut std::collections::BTreeSet<std::path::PathBuf>, git: &Path) {
+    out.insert(git.join("config"));
+    out.insert(git.join("info/exclude"));
+    if let Ok(common) = std::fs::read_to_string(git.join("commondir")) {
+        let common = Path::new(common.trim());
+        let common = if common.is_absolute() { common.to_owned() } else { git.join(common) };
+        out.insert(common.join("config"));
+        out.insert(common.join("info/exclude"));
+    }
+}
+
+/// External ignore/config inputs, including candidates that do not exist yet.
+/// These are outside the directory manifest (`.git` is skipped), so the full
+/// path set must match at warm start.
+pub(crate) fn external_ignore_candidates(root: &Path) -> Vec<std::path::PathBuf> {
+    let mut out = std::collections::BTreeSet::new();
+    if let Some(git) = git_dir(root) {
+        insert_git_inputs(&mut out, &git);
+    }
+    out.insert(root.join(".git/config"));
+    out.insert(root.join(".git/info/exclude"));
+    // The walker also reads the ignore files above the root (`parents`), and a project nested
+    // in a repository uses that repository's exclude file and config.
+    for dir in root.ancestors().skip(1) {
+        out.insert(dir.join(".gitignore"));
+        out.insert(dir.join(".ignore"));
+        if let Some(git) = git_dir(dir) {
+            insert_git_inputs(&mut out, &git);
+        }
+    }
+    if let Some(path) = ignore::gitignore::gitconfig_excludes_path() {
+        out.insert(path);
+    }
+    out.insert(std::path::PathBuf::from("/etc/gitconfig"));
+    if let Some(path) = std::env::var_os("GIT_CONFIG_GLOBAL") {
+        out.insert(path.into());
+    }
+    if let Some(home) = std::env::var_os("HOME") {
+        let home = std::path::PathBuf::from(home);
+        out.insert(home.join(".gitconfig"));
+        out.insert(
+            std::env::var_os("XDG_CONFIG_HOME")
+                .map(std::path::PathBuf::from)
+                .unwrap_or_else(|| home.join(".config"))
+                .join("git/config"),
+        );
+    }
+    out.into_iter().collect()
+}
+
+/// Existing per-directory ignore files. Adding/removing one changes the
+/// directory mtime, which the manifest already validates before this list is used.
+fn per_dir_ignore_candidates(root: &Path, dirs: &[String]) -> Vec<std::path::PathBuf> {
+    let mut out = std::collections::BTreeSet::new();
+    for rel in dirs {
+        let dir = if rel.is_empty() { root.to_owned() } else { root.join(rel) };
+        for name in [".gitignore", ".ignore"] {
+            let path = dir.join(name);
+            if path.is_file() {
+                out.insert(path);
+            }
+        }
+    }
+    out.into_iter().collect()
+}
+
+/// One file's fixed-size columns in the start-up snapshot.
+#[derive(Clone, Copy, Serialize, Deserialize, Default)]
+struct FileMeta {
+    mtime: u64,
+    size: u64,
+    hash: [u8; 32],
+    ignored: bool,
+    /// End of this file's symbols in [`Snapshot::symbols`].
+    sym_end: u32,
+}
+
+/// One symbol's fixed-size columns; names and containers share [`Snapshot::text`].
+#[derive(Clone, Copy, Serialize, Deserialize)]
+struct FlatSymbol {
+    name_start: u32,
+    name_len: u32,
+    container_start: u32,
+    container_len: u32,
+    kind: SymbolKind,
+    range: Range,
+}
+
+/// A columnar copy of the index for fast start-up: a handful of contiguous
+/// arrays and two string arenas instead of one postcard record per redb key.
+#[derive(Serialize, Deserialize, Default)]
+pub(crate) struct Snapshot {
+    rels: String,
+    rel_ends: Vec<u32>,
+    meta: Vec<FileMeta>,
+    symbols: Vec<FlatSymbol>,
+    text: String,
+    dirs: String,
+    dir_ends: Vec<u32>,
+    dir_mtimes: Vec<u64>,
+    dir_counts: Vec<u32>,
+    filter: String,
+    stamp: String,
+    ignore_paths: String,
+    ignore_ends: Vec<u32>,
+    ignore_mtimes: Vec<u64>,
+    ignore_sizes: Vec<u64>,
+    ignore_present: Vec<bool>,
+    ignore_external: Vec<bool>,
+}
+
+impl Snapshot {
+    pub(crate) fn len(&self) -> usize {
+        self.meta.len()
+    }
+
+    pub(crate) fn filter(&self) -> &str {
+        &self.filter
+    }
+
+    pub(crate) fn dirs_len(&self) -> usize {
+        self.dir_mtimes.len()
+    }
+
+    pub(crate) fn dir(&self, dir: usize) -> &str {
+        let start = if dir == 0 { 0 } else { self.dir_ends[dir - 1] as usize };
+        &self.dirs[start..self.dir_ends[dir] as usize]
+    }
+
+    pub(crate) fn dir_mtime(&self, dir: usize) -> u64 {
+        self.dir_mtimes[dir]
+    }
+
+    pub(crate) fn dir_count(&self, dir: usize) -> u32 {
+        self.dir_counts[dir]
+    }
+
+    pub(crate) fn ignore_len(&self) -> usize {
+        self.ignore_mtimes.len()
+    }
+
+    pub(crate) fn ignore_path(&self, i: usize) -> &str {
+        let start = if i == 0 { 0 } else { self.ignore_ends[i - 1] as usize };
+        &self.ignore_paths[start..self.ignore_ends[i] as usize]
+    }
+
+    pub(crate) fn ignore_mtime(&self, i: usize) -> u64 {
+        self.ignore_mtimes[i]
+    }
+
+    pub(crate) fn ignore_size(&self, i: usize) -> u64 {
+        self.ignore_sizes[i]
+    }
+
+    pub(crate) fn ignore_present(&self, i: usize) -> bool {
+        self.ignore_present[i]
+    }
+
+    pub(crate) fn ignore_external(&self, i: usize) -> bool {
+        self.ignore_external[i]
+    }
+
+    pub(crate) fn mtime(&self, file: usize) -> u64 {
+        self.meta[file].mtime
+    }
+
+    pub(crate) fn size(&self, file: usize) -> u64 {
+        self.meta[file].size
+    }
+
+    /// Rejects a corrupt snapshot before any offsets are used for slicing.
+    fn valid(&self) -> bool {
+        let max = u32::MAX as usize;
+        if self.rels.len() > max || self.text.len() > max || self.dirs.len() > max || self.ignore_paths.len() > max {
+            return false;
+        }
+        if self.rel_ends.len() != self.meta.len() {
+            return false;
+        }
+        let boundary = |text: &str, end: u32| end as usize <= text.len() && text.is_char_boundary(end as usize);
+        let mut rel_end = 0;
+        for end in &self.rel_ends {
+            if *end < rel_end || !boundary(&self.rels, *end) {
+                return false;
+            }
+            rel_end = *end;
+        }
+        if rel_end as usize != self.rels.len() {
+            return false;
+        }
+        let mut start = 0;
+        for end in &self.rel_ends {
+            let rel = &self.rels[start..*end as usize];
+            if !crate::data::safe_rel(rel) {
+                return false;
+            }
+            start = *end as usize;
+        }
+        let mut sym_end = 0;
+        for meta in &self.meta {
+            if meta.sym_end < sym_end || meta.sym_end as usize > self.symbols.len() {
+                return false;
+            }
+            sym_end = meta.sym_end;
+        }
+        if sym_end as usize != self.symbols.len() {
+            return false;
+        }
+        if !self.symbols.iter().all(|s| {
+            let Some(name_end) = (s.name_start as usize).checked_add(s.name_len as usize) else {
+                return false;
+            };
+            let Some(container_end) = (s.container_start as usize).checked_add(s.container_len as usize) else {
+                return false;
+            };
+            name_end <= self.text.len()
+                && self.text.is_char_boundary(s.name_start as usize)
+                && self.text.is_char_boundary(name_end)
+                && (s.container_start == u32::MAX
+                    || (s.container_start as usize <= self.text.len()
+                        && container_end <= self.text.len()
+                        && self.text.is_char_boundary(s.container_start as usize)
+                        && self.text.is_char_boundary(container_end)))
+        }) {
+            return false;
+        }
+        if self.dir_ends.len() != self.dir_mtimes.len() || self.dir_counts.len() != self.dir_mtimes.len() {
+            return false;
+        }
+        if self.dir_ends.first() != Some(&0) {
+            return false;
+        }
+        let mut dir_end = 0;
+        for end in &self.dir_ends {
+            if *end < dir_end || !boundary(&self.dirs, *end) {
+                return false;
+            }
+            dir_end = *end;
+        }
+        if dir_end as usize != self.dirs.len() {
+            return false;
+        }
+        let mut start = 0;
+        for end in &self.dir_ends {
+            let dir = &self.dirs[start..*end as usize];
+            if !dir.is_empty() && !crate::data::safe_rel(dir) {
+                return false;
+            }
+            start = *end as usize;
+        }
+        if self.ignore_ends.len() != self.ignore_mtimes.len()
+            || self.ignore_sizes.len() != self.ignore_mtimes.len()
+            || self.ignore_present.len() != self.ignore_mtimes.len()
+            || self.ignore_external.len() != self.ignore_mtimes.len()
+        {
+            return false;
+        }
+        let mut ignore_end = 0;
+        for end in &self.ignore_ends {
+            if *end < ignore_end || !boundary(&self.ignore_paths, *end) {
+                return false;
+            }
+            ignore_end = *end;
+        }
+        if ignore_end as usize != self.ignore_paths.len() {
+            return false;
+        }
+        let mut start = 0;
+        for end in &self.ignore_ends {
+            if start == *end as usize {
+                return false;
+            }
+            start = *end as usize;
+        }
+        true
+    }
+
+    pub(crate) fn rel(&self, file: usize) -> &str {
+        let start = if file == 0 { 0 } else { self.rel_ends[file - 1] as usize };
+        &self.rels[start..self.rel_ends[file] as usize]
+    }
+
+    pub(crate) fn entry(&self, file: usize, root: &Path) -> (FileEntry, Vec<StoredSymbol>) {
+        let meta = self.meta[file];
+        let sym_start = if file == 0 { 0 } else { self.meta[file - 1].sym_end as usize };
+        let symbols = (sym_start..meta.sym_end as usize)
+            .map(|i| {
+                let s = self.symbols[i];
+                let name_start = s.name_start as usize;
+                let name_end = name_start + s.name_len as usize;
+                let name = &self.text[name_start..name_end];
+                let container = (s.container_start != u32::MAX).then(|| {
+                    let start = s.container_start as usize;
+                    &self.text[start..start + s.container_len as usize]
+                });
+                StoredSymbol {
+                    name: name.to_owned(),
+                    kind: s.kind,
+                    container: container.map(str::to_owned),
+                    range: s.range,
+                }
+            })
+            .collect();
+        let rel = self.rel(file);
+        FileEntry::new(
+            root.join(rel),
+            rel.to_owned(),
+            FileRecord { mtime: meta.mtime, size: meta.size, hash: meta.hash, symbols, ignored: meta.ignored },
+        )
+    }
+}
+
 type Result<T> = std::result::Result<T, String>;

 fn err(e: impl std::fmt::Display) -> String {
    e.to_string()
 }

+fn fit(n: usize) -> Result<u32> {
+    u32::try_from(n).map_err(|_| "index snapshot exceeds the 4 GiB span limit".to_owned())
+}
+
 pub(crate) struct Store {
-    /// Write-locked only for [`Store::compact`].
-    db: RwLock<Database>,
+    /// Opened lazily: a valid warm-start snapshot serves start-up without
+    /// touching redb. Write-locked only for [`Store::compact`].
+    db: RwLock<Option<Database>>,
+    /// Columnar warm-start snapshot, kept beside the database.
+    snapshot: std::path::PathBuf,
+    /// Recent-file list, readable without opening redb.
+    recent_file: std::path::PathBuf,
+    stamp: String,
 }

 impl Store {
-    /// Opens (or creates) `cache_dir/index.redb`. Records written by another
-    /// schema / extractor version or for another root are discarded. Returns
-    /// `None` when the database cannot be used (e.g. locked by another window);
-    /// the index then runs in memory only.
+    /// Opens (or creates) the cache directory. The redb database itself is opened
+    /// lazily so a valid columnar snapshot can serve start-up without touching it.
+    /// Returns `None` only when the cache directory cannot be created; the index
+    /// then runs in memory only.
    pub(crate) fn open(cache_dir: &Path, root: &Path, fingerprint: &str) -> Option<Self> {
        if let Err(e) = std::fs::create_dir_all(cache_dir) {
            tracing::warn!("index cache {}: {e}", cache_dir.display());
            return None;
        }
-        let file = cache_dir.join("index.redb");
+        let stamp = format!("{SCHEMA}\n{}\n{fingerprint}\n{}", env!("INDEX_SOURCE_HASH"), root.display());
+        Some(Self {
+            db: RwLock::new(None),
+            snapshot: cache_dir.join("index.snapshot"),
+            recent_file: cache_dir.join("recent.snapshot"),
+            stamp,
+        })
+    }
+
+    fn open_db(&self) -> Result<Database> {
+        let file = self.snapshot.with_file_name("index.redb");
        let db = match Database::create(&file) {
            Ok(db) => db,
            Err(redb::DatabaseError::DatabaseAlreadyOpen) => {
-                tracing::warn!("index cache {} is in use; indexing in memory only", file.display());
-                return None;
+                return Err(format!("{} is in use", file.display()));
            }
            Err(e) => {
                tracing::warn!("index cache {} unreadable ({e}); rebuilding", file.display());
                let _ = std::fs::remove_file(&file);
-                Database::create(&file).map_err(|e| tracing::warn!("index cache: {e}")).ok()?
+                let _ = std::fs::remove_file(&self.snapshot);
+                Database::create(&file).map_err(err)?
            }
        };
-        let store = Self { db: RwLock::new(db) };
-        let stamp = format!("{SCHEMA}\n{}\n{fingerprint}\n{}", env!("INDEX_SOURCE_HASH"), root.display());
-        match store.meta("stamp") {
-            Ok(Some(v)) if v == stamp.as_bytes() => {}
-            _ => {
-                if let Err(e) = store.reset(&stamp) {
-                    tracing::warn!("index cache reset failed: {e}");
-                    return None;
-                }
+        let valid = {
+            let txn = db.begin_read().map_err(err)?;
+            match txn.open_table(META) {
+                Ok(table) => table.get("stamp").map_err(err)?.is_some_and(|v| v.value() == self.stamp.as_bytes()),
+                Err(TableError::TableDoesNotExist(_)) => false,
+                Err(e) => return Err(err(e)),
            }
+        };
+        if !valid {
+            let _ = std::fs::remove_file(&self.snapshot);
+            let _ = std::fs::remove_file(&self.recent_file);
+            Self::reset_db(&db, &self.stamp)?;
        }
-        Some(store)
+        Ok(db)
    }

-    fn meta(&self, key: &str) -> Result<Option<Vec<u8>>> {
-        let txn = self.db.read().begin_read().map_err(err)?;
-        let table = match txn.open_table(META) {
-            Ok(t) => t,
-            Err(TableError::TableDoesNotExist(_)) => return Ok(None),
-            Err(e) => return Err(err(e)),
-        };
-        Ok(table.get(key).map_err(err)?.map(|v| v.value().to_vec()))
+    fn ensure_db(&self) -> Result<()> {
+        if self.db.read().is_some() {
+            return Ok(());
+        }
+        let mut slot = self.db.write();
+        if slot.is_none() {
+            *slot = Some(self.open_db()?);
+        }
+        Ok(())
    }

-    fn reset(&self, stamp: &str) -> Result<()> {
-        let txn = self.db.read().begin_write().map_err(err)?;
+    fn reset_db(db: &Database, stamp: &str) -> Result<()> {
+        let txn = db.begin_write().map_err(err)?;
        match txn.delete_table(FILES) {
            Ok(_) | Err(TableError::TableDoesNotExist(_)) => {}
            Err(e) => return Err(err(e)),
@@ -82,16 +436,31 @@ impl Store {
        txn.commit().map_err(err)
    }

+    fn meta(&self, key: &str) -> Result<Option<Vec<u8>>> {
+        self.ensure_db()?;
+        let db = self.db.read();
+        let txn = db.as_ref().expect("ensured").begin_read().map_err(err)?;
+        let table = match txn.open_table(META) {
+            Ok(t) => t,
+            Err(TableError::TableDoesNotExist(_)) => return Ok(None),
+            Err(e) => return Err(err(e)),
+        };
+        Ok(table.get(key).map_err(err)?.map(|v| v.value().to_vec()))
+    }
+
    /// All persisted records; undecodable entries are skipped (and re-indexed).
    pub(crate) fn load(&self) -> Result<Vec<(String, FileRecord)>> {
-        let txn = self.db.read().begin_read().map_err(err)?;
+        self.ensure_db()?;
+        let db = self.db.read();
+        let txn = db.as_ref().expect("ensured").begin_read().map_err(err)?;
        let table = match txn.open_table(FILES) {
            Ok(t) => t,
            Err(TableError::TableDoesNotExist(_)) => return Ok(Vec::new()),
            Err(e) => return Err(err(e)),
        };
-        let mut out = Vec::new();
-        for item in table.iter().map_err(err)? {
+        let iter = table.iter().map_err(err)?;
+        let mut out = Vec::with_capacity(iter.size_hint().0);
+        for item in iter {
            let (k, v) = item.map_err(err)?;
            if let Ok(rec) = postcard::from_bytes::<FileRecord>(v.value()) {
                out.push((k.value().to_owned(), rec));
@@ -100,10 +469,115 @@ impl Store {
        Ok(out)
    }

+    /// Writes the current index as one columnar snapshot for fast next start-up.
+    /// Only records persisted below `root` are included; content roots outside it
+    /// are rescanned, as they are for the per-file records.
+    pub(crate) fn save_snapshot(&self, data: &IndexData, filter: &PathFilter, not_after: SystemTime) -> Result<()> {
+        let guard = not_after.duration_since(UNIX_EPOCH).map_or(0, |d| d.as_nanos() as u64);
+        let root = filter.root();
+        let mut snap = Snapshot { filter: filter.stamp(), stamp: self.stamp.clone(), ..Default::default() };
+        let mut dirs: std::collections::BTreeSet<String> = std::collections::BTreeSet::new();
+        dirs.insert(String::new());
+        for dir in filter.dirs(root) {
+            if let Ok(rel) = dir.strip_prefix(root) {
+                dirs.insert(rel.to_string_lossy().replace('\\', "/").trim_end_matches('/').to_owned());
+            }
+        }
+        for e in data.files.iter().flatten().filter(|e| e.path.starts_with(root)) {
+            dirs.insert(e.dir().trim_end_matches('/').to_owned());
+            snap.rels.push_str(&e.rel);
+            snap.rel_ends.push(fit(snap.rels.len())?);
+            for s in data.symbols_of(e) {
+                let name_start = fit(snap.text.len())?;
+                snap.text.push_str(s.name);
+                let (container_start, container_len) = match s.container {
+                    Some(c) => {
+                        let start = fit(snap.text.len())?;
+                        snap.text.push_str(c);
+                        (start, fit(c.len())?)
+                    }
+                    None => (u32::MAX, 0),
+                };
+                snap.symbols.push(FlatSymbol {
+                    name_start,
+                    name_len: fit(s.name.len())?,
+                    container_start,
+                    container_len,
+                    kind: s.kind,
+                    range: s.range,
+                });
+            }
+            snap.meta.push(FileMeta {
+                mtime: e.mtime,
+                size: e.size,
+                hash: e.hash,
+                ignored: e.ignored,
+                sym_end: fit(snap.symbols.len())?,
+            });
+        }
+        let dir_list: Vec<String> = dirs.into_iter().collect();
+        for rel in &dir_list {
+            let path = if rel.is_empty() { root.to_owned() } else { root.join(rel) };
+            let mtime = std::fs::symlink_metadata(&path).ok().map(|m| mtime_of(&m)).unwrap_or(0);
+            if mtime > guard {
+                let _ = std::fs::remove_file(&self.snapshot);
+                return Ok(());
+            }
+            let count = if rel.is_empty() {
+                0
+            } else {
+                let key = format!("{rel}/");
+                data.dirs.get(key.as_str()).map_or(0, |d| d.1)
+            };
+            snap.dirs.push_str(rel);
+            snap.dir_ends.push(fit(snap.dirs.len())?);
+            snap.dir_mtimes.push(mtime);
+            snap.dir_counts.push(count);
+        }
+        let external: std::collections::BTreeSet<std::path::PathBuf> =
+            external_ignore_candidates(root).into_iter().collect();
+        let mut candidates: std::collections::BTreeSet<std::path::PathBuf> =
+            per_dir_ignore_candidates(root, &dir_list).into_iter().collect();
+        candidates.extend(external.iter().cloned());
+        for path in candidates {
+            let meta = std::fs::metadata(&path).ok();
+            let present = meta.is_some();
+            let mtime = meta.as_ref().map_or(0, mtime_of);
+            if mtime > guard {
+                let _ = std::fs::remove_file(&self.snapshot);
+                return Ok(());
+            }
+            snap.ignore_paths.push_str(&path.to_string_lossy());
+            snap.ignore_ends.push(fit(snap.ignore_paths.len())?);
+            snap.ignore_mtimes.push(if present { mtime } else { 0 });
+            snap.ignore_sizes.push(if present { meta.as_ref().map_or(0, |m| m.len()) } else { 0 });
+            snap.ignore_present.push(present);
+            snap.ignore_external.push(external.contains(&path));
+        }
+        fit(snap.rels.len())?;
+        fit(snap.text.len())?;
+        fit(snap.dirs.len())?;
+        fit(snap.ignore_paths.len())?;
+        let bytes = postcard::to_allocvec(&snap).map_err(err)?;
+        let tmp = self.snapshot.with_extension("snapshot.tmp");
+        std::fs::write(&tmp, &bytes).map_err(err)?;
+        let _ = std::fs::remove_file(&self.snapshot);
+        std::fs::rename(&tmp, &self.snapshot).map_err(err)
+    }
+
+    /// The columnar start-up snapshot, if it was written and still decodes.
+    pub(crate) fn load_snapshot(&self) -> Option<Snapshot> {
+        let bytes = std::fs::read(&self.snapshot).ok()?;
+        let snapshot: Snapshot = postcard::from_bytes(&bytes).ok()?;
+        (snapshot.stamp == self.stamp && snapshot.valid()).then_some(snapshot)
+    }
+
    /// Applies upserts and deletions in one transaction. Non-durable commits
    /// are cheap (no fsync) and become durable with the next durable one.
    pub(crate) fn apply(&self, puts: &[(String, FileRecord)], deletes: &[String], durable: bool) -> Result<()> {
-        let mut txn = self.db.read().begin_write().map_err(err)?;
+        self.ensure_db()?;
+        let db = self.db.read();
+        let mut txn = db.as_ref().expect("ensured").begin_write().map_err(err)?;
        if !durable {
            txn.set_durability(Durability::None).map_err(err)?;
        }
@@ -120,25 +594,69 @@ impl Store {
                table.remove(rel.as_str()).map_err(err)?;
            }
        }
+        // Any file change makes the columnar start-up snapshot stale.
+        let _ = std::fs::remove_file(&self.snapshot);
+        txn.commit().map_err(err)
+    }
+
+    /// [`Self::apply`] for records already serialized (by the parse pool).
+    pub(crate) fn apply_raw(&self, puts: &[(String, Vec<u8>)], deletes: &[String], durable: bool) -> Result<()> {
+        self.ensure_db()?;
+        let db = self.db.read();
+        let mut txn = db.as_ref().expect("ensured").begin_write().map_err(err)?;
+        if !durable {
+            txn.set_durability(Durability::None).map_err(err)?;
+        }
+        {
+            let mut table = txn.open_table(FILES).map_err(err)?;
+            for (rel, bytes) in puts {
+                table.insert(rel.as_str(), bytes.as_slice()).map_err(err)?;
+            }
+            for rel in deletes {
+                table.remove(rel.as_str()).map_err(err)?;
+            }
+        }
+        // Any file change makes the columnar start-up snapshot stale.
+        let _ = std::fs::remove_file(&self.snapshot);
        txn.commit().map_err(err)
    }

    /// Reclaims free pages in the database file; `true` if anything was compacted.
    pub(crate) fn compact(&self) -> Result<bool> {
-        self.db.write().compact().map_err(err)
+        self.ensure_db()?;
+        let mut db = self.db.write();
+        db.as_mut().expect("ensured").compact().map_err(err)
    }

    pub(crate) fn load_recent(&self) -> Vec<String> {
+        if let Some(recent) = self.load_recent_file() {
+            return recent;
+        }
        self.meta("recent").ok().flatten().and_then(|v| postcard::from_bytes(&v).ok()).unwrap_or_default()
    }

+    /// Recent files without opening redb (the warm-start path).
+    pub(crate) fn load_recent_file(&self) -> Option<Vec<String>> {
+        let bytes = std::fs::read(&self.recent_file).ok()?;
+        postcard::from_bytes(&bytes).ok()
+    }
+
    pub(crate) fn save_recent(&self, recent: &[String]) -> Result<()> {
+        self.save_recent_file(recent)?;
        let bytes = postcard::to_allocvec(recent).map_err(err)?;
        self.set_meta("recent", &bytes)
    }

+    /// Rewrites only the recent sidecar, without opening redb.
+    pub(crate) fn save_recent_file(&self, recent: &[String]) -> Result<()> {
+        let bytes = postcard::to_allocvec(recent).map_err(err)?;
+        std::fs::write(&self.recent_file, &bytes).map_err(err)
+    }
+
    fn set_meta(&self, key: &str, value: &[u8]) -> Result<()> {
-        let txn = self.db.read().begin_write().map_err(err)?;
+        self.ensure_db()?;
+        let db = self.db.read();
+        let txn = db.as_ref().expect("ensured").begin_write().map_err(err)?;
        txn.open_table(META).map_err(err)?.insert(key, value).map_err(err)?;
        txn.commit().map_err(err)
    }
@@ -183,4 +701,58 @@ mod tests {
        let s = Store::open(dir.path(), Path::new("/p"), "fp").unwrap();
        assert!(s.load().unwrap().is_empty());
    }
+
+    #[test]
+    fn snapshot_roundtrips_and_is_invalidated_by_changes() {
+        use crate::data::{FileEntry, IndexData, StoredSymbol};
+        use ide_core::{Range, SymbolKind};
+
+        let dir = tempfile::tempdir().unwrap();
+        let store = Store::open(dir.path(), Path::new("/p"), "fp").unwrap();
+        let record = FileRecord {
+            mtime: 7,
+            size: 3,
+            symbols: vec![StoredSymbol {
+                name: "OrderController".into(),
+                kind: SymbolKind::Class,
+                container: Some("Order".into()),
+                range: Range::default(),
+            }],
+            ..Default::default()
+        };
+        let mut data = IndexData::default();
+        let (entry, symbols) =
+            FileEntry::new(std::path::PathBuf::from("/p/src/Order.rs"), "src/Order.rs".into(), record);
+        data.insert(entry, symbols);
+        // Content roots outside the project root are rescanned, not snapshotted.
+        let (entry, symbols) =
+            FileEntry::new(std::path::PathBuf::from("/elsewhere/x.rs"), "x.rs".into(), FileRecord::default());
+        data.insert(entry, symbols);
+        store
+            .save_snapshot(&data, &PathFilter::new(Path::new("/p"), &Vec::new().into(), &[]), SystemTime::now())
+            .unwrap();
+
+        let snapshot = store.load_snapshot().expect("snapshot");
+        assert_eq!(snapshot.len(), 1);
+        assert_eq!(snapshot.rel(0), "src/Order.rs");
+        let (entry, symbols) = snapshot.entry(0, Path::new("/p"));
+        assert_eq!(&*entry.rel, "src/Order.rs");
+        assert_eq!(symbols.len(), 1);
+        assert_eq!(symbols[0].name, "OrderController");
+        assert_eq!(symbols[0].container.as_deref(), Some("Order"));
+
+        store.apply(&[], &[], false).unwrap();
+        assert!(store.load_snapshot().is_none(), "a file change invalidates the snapshot");
+    }
+
+    #[test]
+    fn snapshot_validation_rejects_bad_paths_and_split_utf8() {
+        let escaping =
+            Snapshot { rels: "../x".into(), rel_ends: vec![4], meta: vec![FileMeta::default()], ..Default::default() };
+        assert!(!escaping.valid());
+
+        let split =
+            Snapshot { rels: "é".into(), rel_ends: vec![1], meta: vec![FileMeta::default()], ..Default::default() };
+        assert!(!split.valid());
+    }
 }
@@ -772,6 +772,95 @@ fn persisted_symbols_do_not_load_through_escaping_symlink_ancestors() {
    assert_eq!(initial.lock()[0], 0, "unsafe cached symbols must never be published");
 }

+#[test]
+fn incremental_changes_refresh_the_warm_start_snapshot() {
+    let f = Fixture::new(&[("src/a.rs", "fn a() {}\n")]);
+    let idx = f.open();
+    let changed = f.write("src/a.rs", "fn renamed() {}\n");
+    idx.update(&[changed], &[]);
+    assert!(idx.wait_idle(WAIT));
+    std::thread::sleep(Duration::from_millis(150));
+    assert!(f.cache.join("index.snapshot").exists(), "a watcher update must regenerate the snapshot");
+}
+
+#[test]
+fn warm_start_detects_changed_ignore_rules() {
+    let f = Fixture::new(&[("sub/generated/a.rs", "fn a() {}\n"), (".git/HEAD", "ref: refs/heads/main\n")]);
+    f.write("sub/.gitignore", "");
+    let idx = f.open();
+    assert_eq!(idx.status().files, 2, "generated/a.rs plus .gitignore itself");
+    drop(idx);
+
+    std::thread::sleep(Duration::from_millis(20));
+    f.write("sub/.gitignore", "generated/\n");
+    let idx = f.open();
+    assert_eq!(idx.status().files, 1, "an updated ignore rule invalidates the warm snapshot");
+}
+
+#[test]
+fn warm_start_detects_changed_ignore_rules_above_the_project() {
+    // The project is a folder of a repository whose ignore files sit above it.
+    let f = Fixture::new(&[("generated/a.rs", "fn a() {}\n"), ("src/b.rs", "fn b() {}\n")]);
+    let repo = f.root.parent().unwrap().to_owned();
+    std::fs::create_dir_all(repo.join(".git/info")).unwrap();
+    std::fs::write(repo.join(".git/HEAD"), "ref: refs/heads/main\n").unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 2);
+    drop(idx);
+
+    std::fs::write(repo.join(".gitignore"), "proj/generated/\n").unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 1, "a new ignore file above the project invalidates the warm snapshot");
+    drop(idx);
+
+    std::thread::sleep(Duration::from_millis(20));
+    std::fs::write(repo.join(".gitignore"), "").unwrap();
+    std::fs::write(repo.join(".git/info/exclude"), "proj/src/\n").unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 1, "so do the enclosing repository's changed rules");
+    assert!(!symbols(&idx, "a", SymbolFilter::All).is_empty());
+}
+
+#[test]
+fn warm_start_detects_a_changed_exclude_file_of_a_linked_worktree() {
+    // The project is a linked worktree: its `.git` file points into the main repository,
+    // whose shared `info/exclude` the walker reads through `commondir`.
+    let f = Fixture::new(&[("generated/a.rs", "fn a() {}\n"), ("src/b.rs", "fn b() {}\n")]);
+    let main = f.root.parent().unwrap().join("main/.git");
+    let worktree = main.join("worktrees/proj");
+    std::fs::create_dir_all(main.join("info")).unwrap();
+    std::fs::create_dir_all(&worktree).unwrap();
+    std::fs::write(main.join("HEAD"), "ref: refs/heads/main\n").unwrap();
+    std::fs::write(worktree.join("HEAD"), "ref: refs/heads/wt\n").unwrap();
+    std::fs::write(worktree.join("commondir"), "../..\n").unwrap();
+    std::fs::write(f.root.join(".git"), format!("gitdir: {}\n", worktree.display())).unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 2);
+    drop(idx);
+
+    std::fs::write(main.join("info/exclude"), "generated/\n").unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 1, "the shared exclude file invalidates the warm snapshot");
+}
+
+#[test]
+fn warm_start_detects_a_new_file_in_an_existing_empty_directory() {
+    let f = Fixture::new(&[("src/a.rs", "fn a() {}\n")]);
+    std::fs::create_dir(f.root.join("empty")).unwrap();
+    let idx = f.open();
+    assert_eq!(idx.status().files, 1);
+    assert!(idx.find_dirs("empty", 10).is_empty());
+    drop(idx);
+    let idx = f.open();
+    assert!(idx.find_dirs("empty", 10).is_empty(), "empty folders are not searchable after warm start");
+    drop(idx);
+
+    f.write("empty/new.rs", "fn new_symbol() {}\n");
+    let idx = f.open();
+    assert_eq!(idx.status().files, 2);
+    assert_eq!(symbols(&idx, "new_symbol", SymbolFilter::All), ["new_symbol"]);
+}
+
 #[test]
 fn rule_changes_refresh_only_the_affected_index_subtree() {
    for (rule, subtree) in [(".git/info/exclude", ""), ("sub/.gitignore", "sub"), ("sub/.ignore", "sub")] {
@@ -834,3 +923,42 @@ fn repository_rule_changes_refresh_members_of_an_unindexed_container() {
    assert!(idx.wait_idle(WAIT));
    assert_eq!(files(&idx, "item.txt"), ["member/generated/item.txt"]);
 }
+
+#[test]
+fn warm_start_sees_edits_deletions_and_renames_made_while_closed() {
+    let f = Fixture::new(&[
+        ("src/a.rs", "fn aaaa() {}\n"),
+        ("src/deep/b.rs", "fn bbbb() {}\n"),
+        ("c.rs", "fn cccc() {}\n"),
+    ]);
+    let idx = f.open();
+    assert!(idx.wait_idle(WAIT));
+    drop(idx);
+    std::thread::sleep(Duration::from_millis(200));
+    // Warm start of an unchanged tree keeps everything.
+    let idx = f.open();
+    assert!(idx.wait_idle(WAIT));
+    assert_eq!(symbols(&idx, "aaaa", SymbolFilter::All), ["aaaa"]);
+    drop(idx);
+    std::thread::sleep(Duration::from_millis(20));
+    // Same size, new content; a deletion; a new file two levels down; a rename.
+    f.write("src/a.rs", "fn zzzz() {}\n");
+    std::fs::remove_file(f.root.join("c.rs")).unwrap();
+    f.write("src/deep/deeper/n.rs", "fn nnnn() {}\n");
+    std::fs::rename(f.root.join("src/deep/b.rs"), f.root.join("src/deep/r.rs")).unwrap();
+    let idx = f.open();
+    assert!(idx.wait_idle(WAIT));
+    assert!(symbols(&idx, "aaaa", SymbolFilter::All).is_empty(), "stale content");
+    assert_eq!(symbols(&idx, "zzzz", SymbolFilter::All), ["zzzz"]);
+    assert!(symbols(&idx, "cccc", SymbolFilter::All).is_empty(), "deleted file");
+    assert_eq!(symbols(&idx, "nnnn", SymbolFilter::All), ["nnnn"]);
+    assert_eq!(symbols(&idx, "bbbb", SymbolFilter::All), ["bbbb"]);
+    assert_eq!(idx.status().files, 3);
+    drop(idx);
+    // After the cold rescan, the next warm start agrees.
+    std::thread::sleep(Duration::from_millis(200));
+    let idx = f.open();
+    assert!(idx.wait_idle(WAIT));
+    assert_eq!(idx.status().files, 3);
+    assert_eq!(symbols(&idx, "zzzz", SymbolFilter::All), ["zzzz"]);
+}
@@ -1,8 +1,8 @@
 //! The background indexing thread: initial load + full scan, then incremental
 //! updates queued by the watcher.

-use crate::data::{FileEntry, FileRecord, IndexData, StoredSymbol};
-use crate::filter::{Found, PathFilter};
+use crate::data::{FileEntry, FileRecord, IndexData, StoredSymbol, safe_rel};
+use crate::filter::{Found, PathFilter, mtime_of};
 use crate::store::Store;
 use ide_core::{IdeEvent, SharedSink, TaskId};
 use ide_language::{LanguageRegistry, Syntax};
@@ -12,12 +12,18 @@ use std::collections::{HashMap, HashSet, VecDeque};
 use std::io::Read;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicBool, Ordering};
-use std::time::{Duration, Instant};
+use std::time::{Duration, Instant, SystemTime};

 /// Files larger than this are listed but not parsed for symbols.
 pub const MAX_SYMBOL_FILE: u64 = 2 * 1024 * 1024;
 const CHUNK: usize = 512;
+/// Insert/persist batch of the initial scan's streaming pass.
+const SCAN_BATCH: usize = 2048;
 const PROGRESS_EVERY: Duration = Duration::from_millis(250);
+#[cfg(not(test))]
+const SNAPSHOT_DELAY: Duration = Duration::from_secs(2);
+#[cfg(test)]
+const SNAPSHOT_DELAY: Duration = Duration::from_millis(50);
 pub(crate) const MAX_RECENT: usize = 50;

 pub(crate) enum Job {
@@ -55,6 +61,11 @@ pub(crate) struct Shared {
    queue: Mutex<Queue>,
    wake: Condvar,
    idle: Condvar,
+    /// Coalesced post-update snapshot refresh.
+    snapshot_due: Mutex<Option<Instant>>,
+    /// Directories whose watcher events still need reconciliation before a
+    /// refreshed snapshot can be trusted.
+    pending_dirs: Mutex<HashSet<PathBuf>>,
 }

 impl Shared {
@@ -79,6 +90,8 @@ impl Shared {
            queue: Mutex::default(),
            wake: Condvar::new(),
            idle: Condvar::new(),
+            snapshot_due: Mutex::default(),
+            pending_dirs: Mutex::default(),
        }
    }

@@ -135,8 +148,15 @@ impl Shared {
            q.busy = true;
        }
        if scan {
-            self.load_persisted();
-            self.full_scan();
+            // A warm start can trust the snapshot when neither the scope nor any
+            // directory/file metadata changed. Rebuilding the walk's file list is
+            // the expensive part; validate the flat manifest first.
+            if !self.try_fast_start() {
+                let snapshot_guard = SystemTime::now();
+                let found = self.walk_roots(None);
+                self.load_persisted(&found);
+                self.full_scan(Some(found), snapshot_guard);
+            }
        } else {
            self.indexing.store(false, Ordering::SeqCst);
        }
@@ -147,17 +167,38 @@ impl Shared {
            self.idle.notify_all();
        }
        loop {
+            let mut save_due = false;
            let jobs: Vec<Job> = {
                let mut q = self.queue.lock();
-                while q.jobs.is_empty() && !self.is_cancelled() {
-                    self.wake.wait(&mut q);
+                loop {
+                    if self.is_cancelled() {
+                        return;
+                    }
+                    if !q.jobs.is_empty() {
+                        break;
+                    }
+                    let due = *self.snapshot_due.lock();
+                    if let Some(due) = due {
+                        if Instant::now() >= due {
+                            save_due = true;
+                            break;
+                        }
+                        self.wake.wait_until(&mut q, due);
+                    } else {
+                        self.wake.wait(&mut q);
+                    }
                }
-                if self.is_cancelled() {
-                    return;
+                if save_due {
+                    Vec::new()
+                } else {
+                    q.busy = true;
+                    q.jobs.drain(..).collect()
                }
-                q.busy = true;
-                q.jobs.drain(..).collect()
            };
+            if save_due {
+                self.save_snapshot_now();
+                continue;
+            }
            self.process(jobs);
            let mut q = self.queue.lock();
            q.busy = false;
@@ -167,27 +208,114 @@ impl Shared {
        }
    }

-    fn load_persisted(&self) {
-        let Some(store) = &self.store else { return };
+    /// Warm start: validate the snapshot's flat directory/file manifest and hydrate
+    /// without walking the tree. A changed scope, symlink, directory mtime, file
+    /// mtime or file size falls back to the full walk.
+    fn try_fast_start(&self) -> bool {
+        let started = Instant::now();
+        let Some(store) = &self.store else { return false };
+        let load_started = Instant::now();
+        let Some(snapshot) = store.load_snapshot() else { return false };
+        let loaded = load_started.elapsed();
        let filter = self.filter();
-        let root = filter.root().to_owned();
-        match store.load() {
-            Ok(records) => {
-                let entries: Vec<(FileEntry, Vec<StoredSymbol>)> = records
-                    .into_par_iter()
-                    .filter(|(rel, _)| {
-                        let path = root.join(rel);
-                        !filter.is_excluded(&path, false) && dunce::canonicalize(&path).is_ok_and(|real| real == path)
-                    })
-                    .map(|(rel, rec)| FileEntry::new(root.join(&rel), rel, rec))
-                    .collect();
-                let mut d = self.data.write();
-                for (e, symbols) in entries {
-                    d.insert(e, symbols);
-                }
-            }
-            Err(e) => tracing::warn!("index cache load failed: {e}"),
+        if filter.has_extra_roots() || snapshot.filter() != filter.stamp() {
+            return false;
        }
+        let root = filter.root();
+        for i in 0..snapshot.dirs_len() {
+            let rel = snapshot.dir(i);
+            let path = if rel.is_empty() { root.to_owned() } else { root.join(rel) };
+            let Ok(meta) = std::fs::symlink_metadata(&path) else { return false };
+            if !meta.is_dir() || mtime_of(&meta) != snapshot.dir_mtime(i) {
+                return false;
+            }
+        }
+        let external = crate::store::external_ignore_candidates(root);
+        let saved_external: Vec<&str> = (0..snapshot.ignore_len())
+            .filter(|&i| snapshot.ignore_external(i))
+            .map(|i| snapshot.ignore_path(i))
+            .collect();
+        if external.len() != saved_external.len()
+            || external.iter().zip(&saved_external).any(|(path, saved)| path.to_string_lossy() != **saved)
+        {
+            return false;
+        }
+        for i in 0..snapshot.ignore_len() {
+            let path = Path::new(snapshot.ignore_path(i));
+            let meta = std::fs::metadata(path).ok();
+            let present = meta.is_some();
+            if present != snapshot.ignore_present(i) {
+                return false;
+            }
+            if let Some(meta) = meta
+                && (mtime_of(&meta) != snapshot.ignore_mtime(i) || meta.len() != snapshot.ignore_size(i))
+            {
+                return false;
+            }
+        }
+        let build_started = Instant::now();
+        let entries: Vec<Option<(FileEntry, Vec<StoredSymbol>)>> = (0..snapshot.len())
+            .into_par_iter()
+            .map(|i| {
+                let path = root.join(snapshot.rel(i));
+                let meta = std::fs::symlink_metadata(&path).ok()?;
+                if !meta.is_file() || mtime_of(&meta) != snapshot.mtime(i) || meta.len() != snapshot.size(i) {
+                    return None;
+                }
+                Some(snapshot.entry(i, root))
+            })
+            .collect();
+        let built = build_started.elapsed();
+        if entries.iter().any(Option::is_none) {
+            return false;
+        }
+        let validated = entries;
+        let mut entries = Vec::with_capacity(validated.len());
+        for entry in validated {
+            entries.push(entry.expect("validated above"));
+        }
+        let dirs: Vec<(Box<str>, PathBuf, u32)> = (0..snapshot.dirs_len())
+            .filter_map(|i| {
+                let rel = snapshot.dir(i);
+                (!rel.is_empty() && snapshot.dir_count(i) > 0).then(|| {
+                    let key = format!("{rel}/");
+                    (key.into_boxed_str(), root.join(rel), snapshot.dir_count(i))
+                })
+            })
+            .collect();
+        let insert_started = Instant::now();
+        let mut d = self.data.write();
+        d.load_bulk(entries, dirs);
+        drop(d);
+        tracing::info!(
+            "index snapshot: warm start in {:?} (load {loaded:?}, validate/build {built:?}, insert {:?})",
+            started.elapsed(),
+            insert_started.elapsed()
+        );
+        #[cfg(test)]
+        eprintln!(
+            "index snapshot: warm start load {loaded:?}, validate/build {built:?}, insert {:?}, total {:?}",
+            insert_started.elapsed(),
+            started.elapsed()
+        );
+        self.indexing.store(false, Ordering::SeqCst);
+        self.emit_state();
+        let recent = store.load_recent_file().unwrap_or_else(|| {
+            let recent = store.load_recent();
+            let _ = store.save_recent_file(&recent);
+            recent
+        });
+        let mut r = self.recent.lock();
+        for p in recent.into_iter().map(|rel| root.join(rel)) {
+            if !r.contains(&p) {
+                r.push(p);
+            }
+        }
+        r.truncate(MAX_RECENT);
+        true
+    }
+
+    fn load_recent(&self, store: &Store, root: &Path) {
        let recent: Vec<PathBuf> = store.load_recent().into_iter().map(|rel| root.join(rel)).collect();
        let mut r = self.recent.lock();
        for p in recent {
@@ -198,6 +326,72 @@ impl Shared {
        r.truncate(MAX_RECENT);
    }

+    fn load_persisted(&self, found: &[Found]) {
+        let Some(store) = &self.store else { return };
+        let root = self.filter().root().to_owned();
+        let seen: HashSet<&Path> = found.iter().map(|f| f.path.as_path()).collect();
+        let started = Instant::now();
+        match store.load_snapshot() {
+            Some(snapshot) => {
+                let entries: Vec<(FileEntry, Vec<StoredSymbol>)> = (0..snapshot.len())
+                    .into_par_iter()
+                    .filter_map(|i| {
+                        let rel = snapshot.rel(i);
+                        if !safe_rel(rel) {
+                            return None;
+                        }
+                        let path = root.join(rel);
+                        seen.contains(path.as_path()).then(|| snapshot.entry(i, &root))
+                    })
+                    .collect();
+                let mut d = self.data.write();
+                let symbols = entries.iter().map(|(_, symbols)| symbols.len()).sum();
+                d.reserve(entries.len(), symbols, 0);
+                for (e, symbols) in entries {
+                    d.insert(e, symbols);
+                }
+                tracing::info!(
+                    "index snapshot: hydrated {} files, {} symbols in {:?}",
+                    d.file_count,
+                    d.symbol_count,
+                    started.elapsed()
+                );
+                #[cfg(test)]
+                eprintln!("index snapshot: hydrated {} files in {:?}", d.file_count, started.elapsed());
+            }
+            None => match store.load() {
+                Ok(records) => {
+                    // Fallback for an index that changed since the snapshot: redb
+                    // records are decoded one file at a time and filtered by the walk.
+                    let entries: Vec<(FileEntry, Vec<StoredSymbol>)> = records
+                        .into_par_iter()
+                        .filter(|(rel, _)| {
+                            safe_rel(rel) && {
+                                let path = root.join(rel);
+                                seen.contains(path.as_path())
+                            }
+                        })
+                        .map(|(rel, rec)| FileEntry::new(root.join(&rel), rel, rec))
+                        .collect();
+                    let mut d = self.data.write();
+                    let symbols = entries.iter().map(|(_, symbols)| symbols.len()).sum();
+                    d.reserve(entries.len(), symbols, 0);
+                    for (e, symbols) in entries {
+                        d.insert(e, symbols);
+                    }
+                    tracing::info!(
+                        "index cache: hydrated {} files, {} symbols in {:?}",
+                        d.file_count,
+                        d.symbol_count,
+                        started.elapsed()
+                    );
+                }
+                Err(e) => tracing::warn!("index cache load failed: {e}"),
+            },
+        }
+        self.load_recent(store, &root);
+    }
+
    /// A cancelled scan (project closed) still ends its progress task and the indexing state.
    fn end_scan(&self, task: TaskId) {
        self.indexing.store(false, Ordering::SeqCst);
@@ -212,11 +406,24 @@ impl Shared {
        self.emit_state();
    }

-    fn full_scan(&self) {
-        self.scan(None);
+    fn walk_roots(&self, dirs: Option<&[PathBuf]>) -> Vec<Found> {
+        let filter = self.filter();
+        let roots: Vec<&Path> = match dirs {
+            Some(dirs) => dirs.iter().map(PathBuf::as_path).collect(),
+            None => filter.roots().collect(),
+        };
+        let mut found = Vec::new();
+        for root in roots {
+            found.extend(filter.walk(root, &self.cancelled));
+        }
+        found
    }

-    fn scan(&self, dirs: Option<&[PathBuf]>) {
+    fn full_scan(&self, found: Option<Vec<Found>>, guard: SystemTime) {
+        self.scan(None, found, guard);
+    }
+
+    fn scan(&self, dirs: Option<&[PathBuf]>, prewalked: Option<Vec<Found>>, guard: SystemTime) {
        let started = Instant::now();
        self.indexing.store(true, Ordering::SeqCst);
        self.emit_state();
@@ -231,17 +438,13 @@ impl Shared {
        });

        let filter = self.filter();
-        let mut found = Vec::new();
-        let roots: Vec<&Path> = match dirs {
-            Some(dirs) => dirs.iter().map(PathBuf::as_path).collect(),
-            None => filter.roots().collect(),
-        };
-        for root in roots {
-            found.extend(filter.walk(root, &self.cancelled));
-        }
+        let walk_started = Instant::now();
+        let found = prewalked.unwrap_or_else(|| self.walk_roots(dirs));
+        let walk = walk_started.elapsed();
        if self.is_cancelled() {
            return self.end_scan(task);
        }
+        let classify_started = Instant::now();
        let seen: HashSet<&Path> = found.iter().map(|f| f.path.as_path()).collect();
        let (todo, stale): (Vec<&Found>, Vec<PathBuf>) = {
            let d = self.data.read();
@@ -254,6 +457,7 @@ impl Shared {
                .collect();
            (todo, stale)
        };
+        let classify = classify_started.elapsed();
        if !stale.is_empty() {
            let mut d = self.data.write();
            for path in &stale {
@@ -264,27 +468,81 @@ impl Shared {
        self.persist(&[], &stale, false);

        let total = todo.len();
-        let mut done = 0usize;
-        let mut last_progress = Instant::now();
-        for chunk in todo.chunks(CHUNK) {
-            if self.is_cancelled() {
-                return self.end_scan(task);
-            }
-            self.index_files(chunk.iter().copied(), false);
-            done += chunk.len();
-            if last_progress.elapsed() >= PROGRESS_EVERY {
-                last_progress = Instant::now();
-                self.sink.emit(IdeEvent::Task {
-                    id: task,
-                    title: "Indexing".into(),
-                    message: Some(format!("{done} / {total} files")),
-                    fraction: Some(done as f32 / total.max(1) as f32),
-                    done: false,
-                    cancellable: false,
+        let mut laps = ChunkLaps::default();
+        {
+            // One streaming parallel pass: parse on the rayon pool without
+            // per-chunk joins (a straggler file at a join's tail idles every
+            // other core), while parsed files flow to this thread to be
+            // inserted and persisted in batches. `filter` moves into the
+            // parse thread; this thread keeps the outer one.
+            let filter = self.filter();
+            // Bounded: when inserting and persisting fall behind, the parse waits instead
+            // of holding the whole project's records (and their bytes) in the channel.
+            let (tx, rx) = std::sync::mpsc::sync_channel::<ParsedFile>(2 * SCAN_BATCH);
+            let cancelled = &self.cancelled;
+            let mut done = 0usize;
+            let mut last_progress = Instant::now();
+            let pass_started = Instant::now();
+            std::thread::scope(|scope| -> () {
+                scope.spawn(move || {
+                    todo.par_iter().for_each(|f| {
+                        if cancelled.load(Ordering::Relaxed) {
+                            return;
+                        }
+                        let Some(out) = self.parse_found(f, &filter, false) else { return };
+                        let _ = tx.send(out);
+                    });
+                    // `tx` drops here: the consumer's loop ends with the channel.
                });
+                let mut batch: Vec<ParsedFile> = Vec::with_capacity(SCAN_BATCH);
+                for out in rx {
+                    if self.is_cancelled() {
+                        break;
+                    }
+                    batch.push(out);
+                    if batch.len() < SCAN_BATCH {
+                        continue;
+                    }
+                    done += batch.len();
+                    laps.add(self.publish(batch.drain(..)));
+                    if last_progress.elapsed() >= PROGRESS_EVERY {
+                        last_progress = Instant::now();
+                        self.sink.emit(IdeEvent::Task {
+                            id: task,
+                            title: "Indexing".into(),
+                            message: Some(format!("{done} / {total} files")),
+                            fraction: Some(done as f32 / total.max(1) as f32),
+                            done: false,
+                            cancellable: false,
+                        });
+                    }
+                }
+                if !batch.is_empty() && !self.is_cancelled() {
+                    done += batch.len();
+                    laps.add(self.publish(batch.drain(..)));
+                }
+            });
+            laps.extract = pass_started.elapsed();
+        }
+        if self.is_cancelled() {
+            return self.end_scan(task);
+        }
+        let durable_started = Instant::now();
+        self.persist(&[], &[], true);
+        let durable = durable_started.elapsed();
+        if let Some(store) = &self.store {
+            let recent: Vec<String> = self.recent.lock().iter().filter_map(|p| filter.store_key(p)).collect();
+            let d = self.data.read();
+            let snapshot_started = Instant::now();
+            if let Err(e) = store.save_snapshot(&d, &filter, guard) {
+                tracing::warn!("index snapshot: {e}");
+            }
+            tracing::info!("index snapshot: written in {:?}", snapshot_started.elapsed());
+            if let Err(e) = store.save_recent_file(&recent) {
+                tracing::warn!("index recent snapshot: {e}");
            }
        }
-        self.persist(&[], &[], true);
+        *self.snapshot_due.lock() = None;
        self.indexing.store(false, Ordering::SeqCst);
        self.sink.emit(IdeEvent::Task {
            id: task,
@@ -297,54 +555,115 @@ impl Shared {
        self.emit_state();
        let d = self.data.read();
        tracing::info!(
-            "indexed {} files ({} parsed, {} symbols) in {:?}",
+            "indexed {} files ({} parsed, {} symbols) in {:?} (walk {:?}, classify {:?}, extract {:?}, insert {:?}, persist {:?}, durable {:?})",
            d.file_count,
            total,
            d.symbol_count,
-            started.elapsed()
+            started.elapsed(),
+            walk,
+            classify,
+            laps.extract,
+            laps.insert,
+            laps.persist,
+            durable
        );
    }

    /// Extracts records in parallel, then publishes them to memory and disk.
    /// `force` re-parses files whose content is unchanged (their language changed).
-    fn index_files<'a>(&self, files: impl Iterator<Item = &'a Found>, force: bool) {
+    fn index_files<'a>(&self, files: impl Iterator<Item = &'a Found>, force: bool) -> ChunkLaps {
+        let mut laps = ChunkLaps::default();
        let files: Vec<&Found> = files.collect();
        let filter = self.filter();
-        let extracted: Vec<(String, FileRecord, PathBuf)> = files
-            .par_iter()
-            .filter_map(|f| {
-                if self.is_cancelled() {
-                    return None;
-                }
-                let rel = filter.rel(&f.path)?;
-                let prev_hash = if force { None } else { self.data.read().get(&f.path).map(|e| e.hash) };
-                match self.extract(f, prev_hash) {
-                    Extracted::Unchanged => {
-                        // Same content, new mtime: keep the symbols, refresh metadata.
-                        let mut rec = self.data.read().record_of(&f.path)?;
-                        rec.mtime = f.mtime;
-                        rec.size = f.size;
-                        rec.ignored = f.ignored;
-                        Some((rel, rec, f.path.clone()))
-                    }
-                    Extracted::New(rec) => Some((rel, rec, f.path.clone())),
-                }
-            })
-            .collect();
+        let started = Instant::now();
+        let extracted: Vec<ParsedFile> = files.par_iter().filter_map(|f| self.parse_found(f, &filter, force)).collect();
+        laps.extract = started.elapsed();
        if extracted.is_empty() {
-            return;
+            return laps;
+        }
+        laps.add(self.publish(extracted.into_iter()));
+        laps
+    }
+
+    /// Reads and parses one file (parallel-safe), serializing its record for
+    /// the cache alongside the parse. `None` when the file is outside the
+    /// scope or the scan was cancelled.
+    fn parse_found(&self, f: &Found, filter: &std::sync::Arc<PathFilter>, force: bool) -> Option<ParsedFile> {
+        if self.is_cancelled() {
+            return None;
+        }
+        let rel = filter.rel(&f.path)?;
+        let prev_hash = if force { None } else { self.data.read().get(&f.path).map(|e| e.hash) };
+        let rec = match self.extract(f, prev_hash) {
+            Extracted::Unchanged => {
+                // Same content, new mtime: keep the symbols, refresh metadata.
+                let mut rec = self.data.read().record_of(&f.path)?;
+                rec.mtime = f.mtime;
+                rec.size = f.size;
+                rec.ignored = f.ignored;
+                rec
+            }
+            Extracted::New(rec) => rec,
+        };
+        let key = filter.store_key(&f.path);
+        let bytes = postcard::to_allocvec(&rec).ok();
+        Some(ParsedFile { rel, rec, key, bytes, path: f.path.clone() })
+    }
+
+    /// Inserts a parsed batch into the in-memory index and persists the records.
+    fn publish(&self, batch: impl Iterator<Item = ParsedFile>) -> ChunkLaps {
+        let mut laps = ChunkLaps::default();
+        let started = Instant::now();
+        let mut entries: Vec<(FileEntry, Vec<StoredSymbol>)> = Vec::new();
+        let mut puts: Vec<(String, Vec<u8>)> = Vec::new();
+        for out in batch {
+            let ParsedFile { rel, rec, key, bytes, path } = out;
+            if let (Some(key), Some(bytes)) = (key, bytes) {
+                puts.push((key, bytes));
+            }
+            entries.push(FileEntry::new(path, rel, rec));
        }
-        let puts: Vec<(String, FileRecord)> =
-            extracted.iter().filter_map(|(_, rec, path)| Some((filter.store_key(path)?, rec.clone()))).collect();
        {
-            let entries: Vec<(FileEntry, Vec<StoredSymbol>)> =
-                extracted.into_iter().map(|(rel, rec, path)| FileEntry::new(path, rel, rec)).collect();
            let mut d = self.data.write();
            for (e, symbols) in entries {
                d.insert(e, symbols);
            }
        }
-        self.persist(&puts, &[], false);
+        laps.insert = started.elapsed();
+        let started = Instant::now();
+        self.persist_raw(&puts, &[], false);
+        laps.persist = started.elapsed();
+        laps
+    }
+
+    fn schedule_snapshot(&self) {
+        if self.store.is_none() {
+            return;
+        }
+        let mut due = self.snapshot_due.lock();
+        if due.is_none() {
+            *due = Some(Instant::now() + SNAPSHOT_DELAY);
+        }
+    }
+
+    fn save_snapshot_now(&self) {
+        let dirs: Vec<PathBuf> = self.pending_dirs.lock().drain().collect();
+        if !dirs.is_empty() {
+            // Reconcile the directories touched since the last scan before
+            // recording their mtimes; otherwise a missed watcher event could be
+            // blessed into the manifest.
+            self.scan(Some(&dirs), None, SystemTime::now());
+            return;
+        }
+        if let Some(store) = &self.store {
+            let filter = self.filter();
+            let guard = SystemTime::now();
+            let d = self.data.read();
+            if let Err(e) = store.save_snapshot(&d, &filter, guard) {
+                tracing::warn!("index snapshot: {e}");
+            }
+        }
+        *self.snapshot_due.lock() = None;
    }

    fn persist(&self, puts: &[(String, FileRecord)], deletes: &[String], durable: bool) {
@@ -355,6 +674,15 @@ impl Shared {
        }
    }

+    /// [`Self::persist`] for records already serialized by the parse pool.
+    fn persist_raw(&self, puts: &[(String, Vec<u8>)], deletes: &[String], durable: bool) {
+        if let Some(store) = &self.store
+            && let Err(e) = store.apply_raw(puts, deletes, durable)
+        {
+            tracing::warn!("index cache write failed: {e}");
+        }
+    }
+
    fn extract(&self, f: &Found, prev_hash: Option<[u8; 32]>) -> Extracted {
        let mut rec = FileRecord { mtime: f.mtime, size: f.size, ignored: f.ignored, ..Default::default() };
        if f.ignored || f.size > MAX_SYMBOL_FILE {
@@ -406,6 +734,17 @@ impl Shared {
                Job::Reparse(before) => reparse.push(before),
            }
        }
+        {
+            let mut pending = self.pending_dirs.lock();
+            for path in changed.iter().chain(removed.iter()) {
+                let dir = if path.is_dir() {
+                    path.clone()
+                } else {
+                    path.parent().map_or_else(|| path.clone(), Path::to_owned)
+                };
+                pending.insert(dir);
+            }
+        }
        if !rule_dirs.is_empty() {
            {
                let mut filter = self.filter.write();
@@ -420,14 +759,14 @@ impl Shared {
                }
            }
            if !rescan {
-                self.scan(Some(&roots));
+                self.scan(Some(&roots), None, SystemTime::now());
                changed.retain(|p| !roots.iter().any(|root| p.starts_with(root)));
                removed.retain(|p| !roots.iter().any(|root| p.starts_with(root)));
            }
        }
        if rescan {
            // The scan also picks up whatever `changed` / `removed` reported.
-            self.full_scan();
+            self.full_scan(None, SystemTime::now());
            changed.clear();
            removed.clear();
        }
@@ -522,6 +861,7 @@ impl Shared {
        if touched {
            self.persist(&[], &[], true);
            self.emit_state();
+            self.schedule_snapshot();
        }
    }
 }
@@ -541,3 +881,44 @@ enum Extracted {
    Unchanged,
    New(FileRecord),
 }
+
+/// Wall-time laps of one `index_files` chunk, accumulated by the scan.
+#[derive(Default)]
+struct ChunkLaps {
+    extract: Duration,
+    insert: Duration,
+    persist: Duration,
+}
+
+impl ChunkLaps {
+    fn add(&mut self, other: ChunkLaps) {
+        self.extract += other.extract;
+        self.insert += other.insert;
+        self.persist += other.persist;
+    }
+}
+
+/// One file parsed off the index thread: its record ready to publish, already
+/// serialized for the cache (in parallel with the parse).
+struct ParsedFile {
+    rel: String,
+    rec: FileRecord,
+    /// Cache key and postcard bytes; `None` when outside the persisted root.
+    key: Option<String>,
+    bytes: Option<Vec<u8>>,
+    path: PathBuf,
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::data::safe_rel;
+
+    #[test]
+    fn cache_keys_stay_below_the_root() {
+        assert!(safe_rel("src/main.rs"));
+        assert!(safe_rel("a/b/c.rs"));
+        for bad in ["", "/etc/passwd", "../out.rs", "a/../../b.rs", "./a.rs"] {
+            assert!(!safe_rel(bad), "{bad:?}");
+        }
+    }
+}
@@ -80,18 +80,47 @@ pub fn trim_line_end(line: &[u8]) -> &[u8] {
    &line[..end]
 }

+/// The longest line kept in full; the rest of a longer one is dropped (a server that writes a
+/// progress bar with `\r` only, or never a newline, must not grow memory without bound).
+pub const MAX_LINE: usize = 8 * 1024;
+
 /// Reads `stream` to its end, calling `on_line` with each line decoded by [`decode`].
 /// Unlike `AsyncBufReadExt::lines`, a line that is not UTF-8 does not end the stream.
+/// A line longer than [`MAX_LINE`] bytes is cut there and ends with `…`.
 pub async fn read_lines<R: AsyncRead + Unpin>(stream: R, mut on_line: impl FnMut(String)) {
    let mut reader = BufReader::new(stream);
    let mut line = Vec::new();
+    let mut cut = false;
    loop {
-        line.clear();
-        match reader.read_until(b'\n', &mut line).await {
-            Ok(0) | Err(_) => break,
-            Ok(_) => on_line(decode(trim_line_end(&line))),
+        let (used, complete) = match reader.fill_buf().await {
+            Ok([]) | Err(_) => break,
+            Ok(buf) => {
+                let end = buf.iter().position(|&b| b == b'\n');
+                let piece = &buf[..end.unwrap_or(buf.len())];
+                let room = MAX_LINE.saturating_sub(line.len());
+                cut |= piece.len() > room;
+                line.extend_from_slice(&piece[..piece.len().min(room)]);
+                (end.map_or(buf.len(), |i| i + 1), end.is_some())
+            }
+        };
+        reader.consume(used);
+        if complete {
+            emit(&mut line, &mut cut, &mut on_line);
        }
    }
+    if !line.is_empty() || cut {
+        emit(&mut line, &mut cut, &mut on_line);
+    }
+}
+
+fn emit(line: &mut Vec<u8>, cut: &mut bool, on_line: &mut impl FnMut(String)) {
+    let mut text = decode(trim_line_end(line));
+    if *cut {
+        text.push('…');
+    }
+    line.clear();
+    *cut = false;
+    on_line(text);
 }

 #[cfg(test)]
@@ -133,4 +162,19 @@ mod tests {
        assert!(lines[1].ends_with(" broken"));
        assert_eq!(lines[2], "last");
    }
+
+    #[tokio::test]
+    async fn a_very_long_line_is_cut_and_the_next_one_is_intact() {
+        let mut input = vec![b'x'; MAX_LINE * 10 + 3];
+        input.extend_from_slice(b"\nnext\r\n");
+        // No newline at all after this one: still bounded.
+        input.extend_from_slice(&vec![b'y'; MAX_LINE * 3]);
+        let mut lines = Vec::new();
+        read_lines(&input[..], |l| lines.push(l)).await;
+        assert_eq!(lines.len(), 3);
+        assert_eq!(lines[0].chars().count(), MAX_LINE + 1);
+        assert!(lines[0].ends_with('…') && lines[0].starts_with("xxx"));
+        assert_eq!(lines[1], "next");
+        assert_eq!(lines[2].chars().count(), MAX_LINE + 1);
+    }
 }
@@ -0,0 +1,56 @@
+; Shell scripts: drawn over the stream mode, which knows only fixed word lists.
+; The last matching pattern wins.
+
+[
+  (string)
+  (raw_string)
+  (ansi_c_string)
+  (translated_string)
+  (heredoc_body)
+  (heredoc_start)
+] @string
+
+[
+  (command_substitution)
+  (process_substitution)
+  (expansion)
+  (simple_expansion)
+] @embedded
+
+(comment) @comment
+
+[
+  "case"
+  "do"
+  "done"
+  "elif"
+  "else"
+  "esac"
+  "fi"
+  "for"
+  "function"
+  "if"
+  "in"
+  "select"
+  "then"
+  "until"
+  "while"
+  "declare"
+  "export"
+  "local"
+  "readonly"
+  "typeset"
+  "unset"
+  "unsetenv"
+] @keyword
+
+(command_name) @function.command
+(function_definition name: (word) @function.definition)
+
+(variable_name) @variable
+(special_variable_name) @variable
+
+[
+  (number)
+  (file_descriptor)
+] @number
@@ -22,12 +22,13 @@ pub use markers::{arduino_sketch_root, is_arduino_sketch_dir, marked_root};
 pub use plugin_point::PluginLanguages;
 pub use registry::{FileTypes, LanguageRegistry};
 pub use syntax::{
-    CSS_CLASS, CSS_ID, CSS_VARIABLE, ConfigurationKey, ExternalFold, ExternalSymbol, ExternalSyntax, ExternalToken,
-    FileReference, Literal, LiteralKind, MAX_CACHED_TREES, MAX_PARSE_BYTES, ParsedTree, SpellingKind, SpellingRegion,
-    Syntax, SyntaxCache, SyntaxCacheStats, SyntaxHighlightKind, SyntaxHighlights, TreeError, VueComponentImport,
-    VueRefAccess, VueRefElement, WebReference, WebReferenceKind, merge_visibility, set_external_syntax, shift_pos,
-    shift_range,
+    CSS_CLASS, CSS_ID, CSS_VARIABLE, ClassBases, ConfigurationKey, ExternalFold, ExternalSymbol, ExternalSyntax,
+    ExternalToken, FileReference, Literal, LiteralKind, MAX_CACHED_TREES, MAX_PARSE_BYTES, ParsedTree, SpellingKind,
+    SpellingRegion, Syntax, SyntaxCache, SyntaxCacheStats, SyntaxHighlightKind, SyntaxHighlights, TreeError,
+    VueComponentImport, VueRefAccess, VueRefElement, WebReference, WebReferenceKind, merge_visibility,
+    set_external_syntax, shift_pos, shift_range,
 };
+pub use syntax::{MethodBody, PythonClassFacts, PythonFacts, PythonMethodFacts};

 /// Parsed form of `languages/<id>.toml`. Backend-only; the UI gets [`LanguageInfo`].
 #[derive(Clone, Debug, Serialize, Deserialize)]
@@ -198,6 +199,10 @@ pub struct LanguageServerConfig {
    /// it parses a document.
    #[serde(default)]
    pub resync_on_configuration: bool,
+    /// Set by the settings hook: what the user sees as the server when another program serves
+    /// in its place (TypeScript 7's own `tsc --lsp` for vtsls).
+    #[serde(skip)]
+    pub display_name: Option<String>,
    /// Set on plugin languages: start exactly this approved program.
    #[serde(skip)]
    pub pinned: Option<ProgramPin>,
@@ -40,6 +40,7 @@ const BUILTIN: &[(&str, &str)] = &[
    ("groovy", include_str!("../../../languages/groovy.toml")),
    ("haskell", include_str!("../../../languages/haskell.toml")),
    ("hcl", include_str!("../../../languages/hcl.toml")),
+    ("helm-template", include_str!("../../../languages/helm-template.toml")),
    ("html", include_str!("../../../languages/html.toml")),
    ("http", include_str!("../../../languages/http.toml")),
    ("ignore", include_str!("../../../languages/ignore.toml")),
@@ -548,6 +549,7 @@ mod tests {
        "Groovy",
        "Haskell",
        "Haxe",
+        "Helm Template",
        "HXML",
        "HTTP",
        "IDL",
@@ -841,6 +843,30 @@ mod tests {
        assert!(reg.is_framework_marker(&root.join("src/manage.py")));
    }

+    #[test]
+    fn helm_charts_make_yaml_and_notes_in_templates_folders_helm_templates() {
+        let reg = reg();
+        let tmp = tempfile::tempdir().unwrap();
+        let root = tmp.path();
+        let detect = |file: &str| reg.detect(&root.join(file), None).as_str().to_owned();
+        std::fs::create_dir_all(root.join("charts/podinfo/templates/tests")).unwrap();
+        std::fs::create_dir_all(root.join("k8s/templates")).unwrap();
+        std::fs::write(root.join("charts/podinfo/Chart.yaml"), "apiVersion: v2\nname: podinfo\n").unwrap();
+        assert_eq!(detect("charts/podinfo/Chart.yaml"), "yaml");
+        assert_eq!(detect("charts/podinfo/values.yaml"), "yaml");
+        assert_eq!(detect("charts/podinfo/templates/deployment.yaml"), "helm-template");
+        assert_eq!(detect("charts/podinfo/templates/tests/connection.yml"), "helm-template");
+        assert_eq!(detect("charts/podinfo/templates/_helpers.tpl"), "helm-template");
+        assert_eq!(detect("charts/podinfo/templates/NOTES.txt"), "helm-template");
+        // No `Chart.yaml` / `Chart.yml` above this `templates` folder.
+        assert_eq!(detect("k8s/templates/deployment.yaml"), "yaml");
+        assert_eq!(detect("common.gotmpl"), "helm-template");
+        // Outside a chart, `.tpl` belongs to other template engines (Smarty, Terraform).
+        assert_ne!(detect("site/index.tpl"), "helm-template");
+        assert!(reg.is_framework_marker(&root.join("charts/podinfo/Chart.yaml")));
+        assert!(reg.is_framework_marker(&root.join("charts/podinfo/Chart.yml")));
+    }
+
    #[test]
    fn the_django_fixture_has_templates_and_a_page() {
        let reg = reg();
@@ -314,7 +314,7 @@ pub(crate) static SPECS: &[Spec] = &[
        name: "bash",
        language: tree_sitter_bash::LANGUAGE,
        outline: outline!("bash"),
-        highlights: None,
+        highlights: Some(Highlights { query: highlights!("bash"), first_wins: false }),
        fold_nodes: &["do_group", "if_statement", "case_statement", "heredoc_body"],
        fold_bodies: NONE,
        imports: NONE,
@@ -43,11 +43,13 @@ pub enum SyntaxHighlightKind {
    Operator,
    Punctuation,
    Parameter,
+    /// A shell command name (`pgrep`, a script's own function).
+    Command,
 }

 impl SyntaxHighlightKind {
    /// Every kind, in `as u32` order: the legend for [`SyntaxHighlights::data`].
-    pub const ALL: [Self; 25] = [
+    pub const ALL: [Self; 26] = [
        Self::Keyword,
        Self::String,
        Self::StringSpecial,
@@ -73,6 +75,7 @@ impl SyntaxHighlightKind {
        Self::Operator,
        Self::Punctuation,
        Self::Parameter,
+        Self::Command,
    ];

    /// The kebab-case name plugins use (`doc-comment`, `function-call`, …).
@@ -153,6 +156,7 @@ const CAPTURES: &[(&str, Paint)] = {
        ("function.builtin", Kind(K::Builtin)),
        ("function.macro", Kind(K::Macro)),
        ("function.definition", Kind(K::Function)),
+        ("function.command", Kind(K::Command)),
        ("function", Kind(K::FunctionCall)),
        ("method", Kind(K::FunctionCall)),
        ("constructor", Kind(K::Type)),
@@ -408,6 +412,30 @@ mod tests {
        }
    }

+    #[test]
+    fn shell_scripts_highlight_declarations_commands_and_function_names() {
+        use SyntaxHighlightKind as K;
+        let src = "this::check_process() {\n  local process\n  process=\"${1:?}\"\n  if [ -x \"$(command -v pgrep)\" ]; then\n    if pgrep -f -q \"${process}\"; then\n      functions::exit 1 \"'${process}' is running\"\n    fi\n  fi\n}\n# done\n";
+        let got = spans("shellscript", src);
+        for (text, expected) in [
+            ("this::check_process", K::Function),
+            ("local", K::Keyword),
+            ("if", K::Keyword),
+            ("command", K::Command),
+            ("pgrep", K::Command),
+            ("functions::exit", K::Command),
+            ("process", K::Variable),
+            ("# done", K::Comment),
+        ] {
+            assert!(
+                got.iter().any(|(word, kind)| word == text && *kind == expected),
+                "missing {text}: {expected:?} in {got:?}"
+            );
+        }
+        // An expansion inside a string is not string-coloured.
+        assert!(!got.iter().any(|(word, kind)| word.contains("${process}") && *kind == K::String), "{got:?}");
+    }
+
    #[test]
    fn non_kotlin_parameters_keep_variable_highlighting() {
        for (lang, src) in [
@@ -0,0 +1,176 @@
+//! Extraction of Python class base names, used to build an inheritance graph
+//! without an LSP `typeHierarchyProvider`.
+
+use super::lines::LineIndex;
+use crate::{LanguageId, Syntax};
+use tree_sitter::{Node, Tree};
+
+/// A Python class definition and the base names written in its source.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct ClassBases {
+    /// The class name (bare identifier).
+    pub name: String,
+    /// 0-based line of the class name (selection-range start).
+    pub line: u32,
+    /// 0-based UTF-16 column of the class name (selection-range start).
+    pub col: u32,
+    /// Source-written base names (last segment of a qualified name).
+    pub bases: Vec<String>,
+}
+
+impl Syntax {
+    /// Class definitions of `text` with their base names, in source order.
+    /// Only Python is supported; every other language returns an empty vector.
+    pub fn class_bases(&self, lang: &LanguageId, text: &str) -> Vec<ClassBases> {
+        self.analyze(lang, text, |g, tree, text| (g.spec.name == "python").then(|| extract(tree, text)))
+            .unwrap_or_default()
+    }
+}
+
+fn extract(tree: &Tree, text: &str) -> Vec<ClassBases> {
+    let idx = LineIndex::new(text);
+    let mut out = Vec::new();
+    let mut cursor = tree.walk();
+    visit(&mut cursor, &mut |node| {
+        if node.kind() != "class_definition" {
+            return;
+        }
+        let Some(name_node) = node.child_by_field_name("name") else { return };
+        let name = text.get(name_node.byte_range()).unwrap_or_default().to_owned();
+        if name.is_empty() {
+            return;
+        }
+        // Selection-range start of the class: its name identifier (`class Foo`
+        // -> `Foo`), matching `outline.rs` and the gutter marker candidates.
+        let range = idx.range(name_node.start_byte(), name_node.end_byte());
+        let bases = class_base_names(node, text);
+        out.push(ClassBases { name, line: range.start.line, col: range.start.col, bases });
+    });
+    out
+}
+
+/// Depth-first pre-order traversal of all descendants of `cursor`'s node.
+fn visit(cursor: &mut tree_sitter::TreeCursor, f: &mut impl FnMut(Node)) {
+    loop {
+        f(cursor.node());
+        if cursor.goto_first_child() {
+            continue;
+        }
+        loop {
+            if cursor.goto_next_sibling() {
+                break;
+            }
+            if !cursor.goto_parent() {
+                return;
+            }
+        }
+    }
+}
+
+/// The bare base names a `class_definition` node writes (keyword arguments left out).
+pub(super) fn class_base_names(node: Node, text: &str) -> Vec<String> {
+    node.child_by_field_name("superclasses").map(|args| base_names(args, text)).unwrap_or_default()
+}
+
+fn base_names(args: Node, text: &str) -> Vec<String> {
+    let mut out = Vec::new();
+    let mut cursor = args.walk();
+    for arg in args.named_children(&mut cursor) {
+        if let Some(name) = base_name(arg, text) {
+            out.push(name);
+        }
+    }
+    out
+}
+
+/// Bare name of one base expression, or `None` for keyword arguments and
+/// expressions that are not a (possibly qualified) name.
+fn base_name(arg: Node, text: &str) -> Option<String> {
+    match arg.kind() {
+        "identifier" => text.get(arg.byte_range()).map(str::to_owned),
+        // `pkg.mod.Base` -> `Base`.
+        "attribute" => {
+            let attr = arg.child_by_field_name("attribute")?;
+            (attr.kind() == "identifier").then(|| text.get(attr.byte_range()).unwrap_or_default().to_owned())
+        }
+        // `Generic[T]` -> `Generic`.
+        "subscript" => {
+            let value = arg.child_by_field_name("value")?;
+            (value.kind() == "identifier").then(|| text.get(value.byte_range()).unwrap_or_default().to_owned())
+        }
+        // `metaclass=Meta`, `**kwargs`, `*bases` and other expressions.
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn bases(src: &str) -> Vec<ClassBases> {
+        static S: std::sync::OnceLock<Syntax> = std::sync::OnceLock::new();
+        S.get_or_init(Syntax::new).class_bases(&LanguageId::new("python"), src)
+    }
+
+    fn shape(src: &str) -> Vec<(String, u32, u32, Vec<String>)> {
+        bases(src).into_iter().map(|c| (c.name, c.line, c.col, c.bases)).collect()
+    }
+
+    #[test]
+    fn no_bases() {
+        assert_eq!(shape("class A: pass"), vec![("A".to_owned(), 0, 6, vec![])]);
+    }
+
+    #[test]
+    fn multiple_bases_skips_metaclass() {
+        assert_eq!(
+            shape("class B(A, C, metaclass=Meta): pass"),
+            vec![("B".to_owned(), 0, 6, vec!["A".to_owned(), "C".to_owned()])]
+        );
+    }
+
+    #[test]
+    fn qualified_name_takes_last_segment() {
+        assert_eq!(shape("class D(pkg.mod.Base): pass"), vec![("D".to_owned(), 0, 6, vec!["Base".to_owned()])]);
+    }
+
+    #[test]
+    fn subscript_takes_value() {
+        assert_eq!(shape("class E(Generic[T]): pass"), vec![("E".to_owned(), 0, 6, vec!["Generic".to_owned()])]);
+    }
+
+    #[test]
+    fn multiline_bases() {
+        let src = "class F(\n    A,\n    B,\n):\n    pass";
+        assert_eq!(shape(src), vec![("F".to_owned(), 0, 6, vec!["A".to_owned(), "B".to_owned()])]);
+    }
+
+    #[test]
+    fn nested_classes() {
+        let src = "class Outer:\n    class Inner(Y):\n        pass";
+        assert_eq!(
+            shape(src),
+            vec![("Outer".to_owned(), 0, 6, vec![]), ("Inner".to_owned(), 1, 10, vec!["Y".to_owned()]),]
+        );
+    }
+
+    #[test]
+    fn comments_and_strings_are_ignored() {
+        let src = r#"
+# class Fake(Nope): pass
+doc = """
+class InDocstring(X): pass
+"""
+s = 'class InString(Y): pass'
+class Real(Base): pass
+"#;
+        assert_eq!(shape(src), vec![("Real".to_owned(), 6, 6, vec!["Base".to_owned()])]);
+    }
+
+    #[test]
+    fn other_languages_are_empty() {
+        static S: std::sync::OnceLock<Syntax> = std::sync::OnceLock::new();
+        let s = S.get_or_init(Syntax::new);
+        assert!(s.class_bases(&LanguageId::new("rust"), "struct A;").is_empty());
+    }
+}
@@ -6,9 +6,11 @@ mod external;
 mod folding;
 mod grammars;
 mod highlight;
+mod inheritance;
 pub(crate) mod lines;
 mod literals;
 mod outline;
+mod python_facts;
 mod rst;
 mod selection;
 mod sfc;
@@ -22,9 +24,11 @@ pub use external::{ExternalFold, ExternalSymbol, ExternalSyntax, ExternalToken,
 use grammars::{SPECS, Spec};
 pub use highlight::{SyntaxHighlightKind, SyntaxHighlights};
 use ide_core::{LanguageId, OutlineItem, Pos, Range};
+pub use inheritance::ClassBases;
 pub use lines::{shift_pos, shift_range};
 pub use literals::{Literal, LiteralKind, SpellingKind, SpellingRegion};
 pub use outline::merge_visibility;
+pub use python_facts::{MethodBody, PythonClassFacts, PythonFacts, PythonMethodFacts};
 use std::cell::RefCell;
 use std::collections::HashMap;
 use std::sync::OnceLock;
@@ -0,0 +1,438 @@
+//! Python class facts the inheritance inspections need: base names as written, parameter
+//! lists, decorator semantics and what a method body does. They come from the syntax tree in
+//! one pass, so the frontend reasons about the inheritance graph without parsing source text.
+//!
+//! Deliberately small: a fact exists here only when a check can decide it without guessing.
+
+use super::lines::LineIndex;
+use crate::{LanguageId, Syntax};
+use serde::{Deserialize, Serialize};
+use specta::Type;
+use tree_sitter::{Node, Tree};
+
+/// One Python module's classes, in source order.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct PythonFacts {
+    pub classes: Vec<PythonClassFacts>,
+}
+
+/// A class definition and the methods it declares.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct PythonClassFacts {
+    pub name: String,
+    /// The class name identifier (selection range).
+    pub selection: crate::Range,
+    /// Base names as written, a qualified name reduced to its last segment.
+    pub bases: Vec<String>,
+    pub methods: Vec<PythonMethodFacts>,
+}
+
+/// A method definition the inspections can reason about.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase")]
+pub struct PythonMethodFacts {
+    pub name: String,
+    /// The method name identifier (selection range).
+    pub selection: crate::Range,
+    /// Parameter names in order; `None` for a form whose forwarding cannot be compared
+    /// (`*args`, `**kwargs`, keyword-only, positional-only).
+    pub params: Option<Vec<String>>,
+    /// Decorated with `abstractmethod` (`abc.abstractmethod` included).
+    pub abstract_method: bool,
+    /// Decorated with `override` from `typing` / `typing_extensions`.
+    pub override_decorated: bool,
+    pub body: MethodBody,
+}
+
+/// What a method body does, for the shapes a check can decide without guessing.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase", tag = "kind")]
+pub enum MethodBody {
+    /// `pass`, `...`, a docstring, or nothing at all.
+    Empty,
+    /// Exactly one `super().name(args)` call, optionally `return`ed.
+    SuperCall { returns: bool, target: String, args: Vec<String> },
+    /// Anything else.
+    Other,
+}
+
+impl Syntax {
+    /// The classes of a Python `text` with the facts the inheritance checks need.
+    /// Every other language returns an empty result.
+    pub fn python_facts(&self, lang: &LanguageId, text: &str) -> PythonFacts {
+        self.analyze(lang, text, |g, tree, text| (g.spec.name == "python").then(|| extract(tree, text)))
+            .unwrap_or_default()
+    }
+}
+
+fn extract(tree: &Tree, text: &str) -> PythonFacts {
+    let idx = LineIndex::new(text);
+    let imports = ImportBindings::collect(tree, text);
+    let mut classes = Vec::new();
+    let mut cursor = tree.walk();
+    visit(&mut cursor, &mut |node| {
+        if node.kind() != "class_definition" {
+            return;
+        }
+        let Some(name_node) = node.child_by_field_name("name") else { return };
+        let name = text_of(name_node, text);
+        if name.is_empty() {
+            return;
+        }
+        classes.push(PythonClassFacts {
+            name,
+            selection: idx.range(name_node.start_byte(), name_node.end_byte()),
+            bases: super::inheritance::class_base_names(node, text),
+            methods: methods_of(node, text, &idx, &imports),
+        });
+    });
+    PythonFacts { classes }
+}
+
+/// The methods declared directly in `class`.
+fn methods_of(class: Node, text: &str, idx: &LineIndex, imports: &ImportBindings) -> Vec<PythonMethodFacts> {
+    let Some(body) = class.child_by_field_name("body") else { return Vec::new() };
+    let mut out = Vec::new();
+    let mut cursor = body.walk();
+    for member in body.named_children(&mut cursor) {
+        // A decorated method is a `decorated_definition` wrapping the `function_definition`.
+        let method = match member.kind() {
+            "function_definition" => member,
+            "decorated_definition" => match member.child_by_field_name("definition") {
+                Some(inner) if inner.kind() == "function_definition" => inner,
+                _ => continue,
+            },
+            _ => continue,
+        };
+        let Some(name_node) = method.child_by_field_name("name") else { continue };
+        let name = text_of(name_node, text);
+        if name.is_empty() {
+            continue;
+        }
+        let decorators = decorators_of(method, text);
+        out.push(PythonMethodFacts {
+            name,
+            selection: idx.range(name_node.start_byte(), name_node.end_byte()),
+            params: parameters_of(method, text),
+            abstract_method: decorators.iter().any(|d| last_segment(d) == "abstractmethod"),
+            override_decorated: decorators.iter().any(|d| imports.is_typing_override(d)),
+            body: body_of(method, text),
+        });
+    }
+    out
+}
+
+/// The parameter names of a `function_definition`, or `None` when the signature contains a
+/// form whose forwarding cannot be compared without guessing.
+fn parameters_of(function: Node, text: &str) -> Option<Vec<String>> {
+    let params = function.child_by_field_name("parameters")?;
+    let mut names = Vec::new();
+    let mut cursor = params.walk();
+    for param in params.named_children(&mut cursor) {
+        let name = match param.kind() {
+            "identifier" => text_of(param, text),
+            "typed_parameter" | "default_parameter" | "typed_default_parameter" => {
+                let named = param
+                    .child_by_field_name("name")
+                    .or_else(|| param.child_by_field_name("pattern"))
+                    .or_else(|| param.named_child(0))?;
+                if named.kind() != "identifier" {
+                    return None;
+                }
+                text_of(named, text)
+            }
+            // `*args`, `**kwargs`, `/`, `*`: the call form cannot be compared textually.
+            _ => return None,
+        };
+        if !name.is_empty() {
+            names.push(name);
+        }
+    }
+    Some(names)
+}
+
+/// A `function_definition`'s body, classified into the shapes a check can decide.
+fn body_of(function: Node, text: &str) -> MethodBody {
+    let Some(body) = function.child_by_field_name("body") else { return MethodBody::Empty };
+    // A docstring is not a statement the checks care about.
+    let statements: Vec<Node> = statements_of(body).into_iter().filter(|s| !is_string(*s)).collect();
+    if statements.is_empty() || statements.iter().all(|s| is_noop(*s)) {
+        return MethodBody::Empty;
+    }
+    let [only] = statements.as_slice() else { return MethodBody::Other };
+    let call = match only.kind() {
+        "expression_statement" => (only.named_child(0), false),
+        "return_statement" => (only.named_child(0), true),
+        _ => (None, false),
+    };
+    match call {
+        (Some(call), returns) if is_super_call(call, text) => {
+            let target = call
+                .child_by_field_name("function")
+                .and_then(|f| f.child_by_field_name("attribute"))
+                .map(|a| text_of(a, text))
+                .unwrap_or_default();
+            let args = call
+                .child_by_field_name("arguments")
+                .map(|args| {
+                    let mut cursor = args.walk();
+                    args.named_children(&mut cursor).map(|a| text_of(a, text)).collect()
+                })
+                .unwrap_or_default();
+            MethodBody::SuperCall { returns, target, args }
+        }
+        _ => MethodBody::Other,
+    }
+}
+
+/// Whether `node` is a `super().name(...)` call.
+fn is_super_call(node: Node, text: &str) -> bool {
+    if node.kind() != "call" {
+        return false;
+    }
+    let Some(function) = node.child_by_field_name("function") else { return false };
+    if function.kind() != "attribute" {
+        return false;
+    }
+    function.child_by_field_name("object").is_some_and(|object| {
+        object.kind() == "call"
+            && object
+                .child_by_field_name("function")
+                .is_some_and(|f| f.kind() == "identifier" && text_of(f, text) == "super")
+    })
+}
+
+/// Whether `statement` is `pass` or a bare `...`.
+fn is_noop(statement: Node) -> bool {
+    match statement.kind() {
+        "pass_statement" => true,
+        "expression_statement" => statement.named_child(0).is_some_and(|child| child.kind() == "ellipsis"),
+        _ => false,
+    }
+}
+
+/// A string expression statement: a docstring.
+fn is_string(statement: Node) -> bool {
+    statement.kind() == "expression_statement" && statement.named_child(0).is_some_and(|child| child.kind() == "string")
+}
+
+/// The statements of a `block`, comments excluded.
+fn statements_of(block: Node) -> Vec<Node> {
+    let mut cursor = block.walk();
+    block.named_children(&mut cursor).filter(|child| child.kind() != "comment").collect()
+}
+
+/// The decorators written on a definition, without the `@` or the call arguments.
+fn decorators_of(definition: Node, text: &str) -> Vec<String> {
+    let Some(parent) = definition.parent() else { return Vec::new() };
+    if parent.kind() != "decorated_definition" {
+        return Vec::new();
+    }
+    let mut out = Vec::new();
+    let mut cursor = parent.walk();
+    for decorator in parent.named_children(&mut cursor) {
+        if decorator.kind() != "decorator" {
+            continue;
+        }
+        let Some(inner) = decorator.named_child(0) else { continue };
+        let target =
+            if inner.kind() == "call" { inner.child_by_field_name("function").unwrap_or(inner) } else { inner };
+        let name = text_of(target, text).trim().to_owned();
+        if !name.is_empty() {
+            out.push(name);
+        }
+    }
+    out
+}
+
+/// The last segment of a dotted name (`typing.override` -> `override`).
+fn last_segment(name: &str) -> &str {
+    name.rsplit('.').next().unwrap_or(name)
+}
+
+fn text_of(node: Node, text: &str) -> String {
+    text.get(node.byte_range()).unwrap_or_default().to_owned()
+}
+
+/// The module-level `from ... import ...` bindings, so `override` can be told apart from a
+/// same-named decorator of another library.
+struct ImportBindings {
+    /// (local name, module, exported name)
+    bindings: Vec<(String, String, String)>,
+}
+
+impl ImportBindings {
+    fn collect(tree: &Tree, text: &str) -> Self {
+        let mut bindings = Vec::new();
+        let mut cursor = tree.walk();
+        visit(&mut cursor, &mut |node| {
+            if node.kind() != "import_from_statement" {
+                return;
+            }
+            let Some(module) = node.child_by_field_name("module_name") else { return };
+            let module = text_of(module, text);
+            let mut names = node.walk();
+            for name in node.children_by_field_name("name", &mut names) {
+                let (local, exported) = match name.kind() {
+                    "aliased_import" => (
+                        name.child_by_field_name("alias").map(|n| text_of(n, text)),
+                        name.child_by_field_name("name").map(|n| text_of(n, text)),
+                    ),
+                    _ => {
+                        let written = text_of(name, text);
+                        (Some(written.clone()), Some(written))
+                    }
+                };
+                if let (Some(local), Some(exported)) = (local, exported) {
+                    bindings.push((local, module.clone(), exported));
+                }
+            }
+        });
+        Self { bindings }
+    }
+
+    /// Whether `decorator` names `override` from `typing` / `typing_extensions`.
+    fn is_typing_override(&self, decorator: &str) -> bool {
+        const MODULES: [&str; 2] = ["typing", "typing_extensions"];
+        let segments: Vec<&str> = decorator.split('.').filter(|s| !s.is_empty()).collect();
+        match segments.as_slice() {
+            // `@typing.override`, or `@t.override` after `import typing as t`.
+            [prefix, "override"] => {
+                MODULES.contains(prefix)
+                    || self
+                        .bindings
+                        .iter()
+                        .find(|(local, _, _)| local == prefix)
+                        .is_some_and(|(_, module, _)| MODULES.contains(&module.as_str()))
+            }
+            // `@override`, or `@ov` after `from typing import override as ov`.
+            [local] => match self.bindings.iter().find(|(bound, _, _)| bound == local) {
+                Some((_, module, exported)) => exported == "override" && MODULES.contains(&module.as_str()),
+                // Nothing contradicts a bare `@override`: the usual `from typing import *`.
+                None => *local == "override",
+            },
+            _ => false,
+        }
+    }
+}
+
+/// Depth-first pre-order traversal of all descendants of `cursor`'s node.
+fn visit(cursor: &mut tree_sitter::TreeCursor, f: &mut impl FnMut(Node)) {
+    loop {
+        f(cursor.node());
+        if cursor.goto_first_child() {
+            continue;
+        }
+        loop {
+            if cursor.goto_next_sibling() {
+                break;
+            }
+            if !cursor.goto_parent() {
+                return;
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    static SYNTAX: std::sync::OnceLock<Syntax> = std::sync::OnceLock::new();
+
+    fn facts(src: &str) -> PythonFacts {
+        SYNTAX.get_or_init(Syntax::new).python_facts(&LanguageId::new("python"), src)
+    }
+
+    fn method<'a>(facts: &'a PythonFacts, class: &str, method: &str) -> &'a PythonMethodFacts {
+        facts
+            .classes
+            .iter()
+            .find(|c| c.name == class)
+            .and_then(|c| c.methods.iter().find(|m| m.name == method))
+            .expect("method not found")
+    }
+
+    #[test]
+    fn classes_carry_bases_and_methods() {
+        let f = facts(
+            "class Base(ABC):\n    pass\n\nclass Child(Base, pkg.Mixin):\n    def run(self, x=1):\n        pass\n",
+        );
+        assert_eq!(f.classes.len(), 2);
+        assert_eq!(f.classes[0].name, "Base");
+        assert_eq!(f.classes[0].bases, ["ABC"]);
+        assert_eq!(f.classes[1].bases, ["Base", "Mixin"]);
+        assert_eq!(f.classes[1].methods.len(), 1);
+        assert_eq!(f.classes[1].selection.start.line, 3);
+        assert_eq!(f.classes[1].selection.start.col, 6);
+    }
+
+    #[test]
+    fn parameters_are_names_in_order_and_none_for_splats() {
+        let f = facts(
+            "class C:\n    def a(self, x: int, y=2):\n        pass\n\n    def b(self, *args):\n        pass\n\n    def c(self, *, x):\n        pass\n",
+        );
+        assert_eq!(
+            method(&f, "C", "a").params.as_deref(),
+            Some(["self".to_string(), "x".to_string(), "y".to_string()].as_slice())
+        );
+        assert_eq!(method(&f, "C", "b").params, None);
+        assert_eq!(method(&f, "C", "c").params, None);
+    }
+
+    #[test]
+    fn body_shapes_are_classified() {
+        let f = facts(
+            "class C:\n    def noop(self):\n        pass\n\n    def dots(self):\n        ...\n\n    def doc(self):\n        \"\"\"text\"\"\"\n\n    def forward(self, x):\n        return super().run(x)\n\n    def call(self):\n        super().run()\n\n    def other(self):\n        return 1\n",
+        );
+        assert_eq!(method(&f, "C", "noop").body, MethodBody::Empty);
+        assert_eq!(method(&f, "C", "dots").body, MethodBody::Empty);
+        assert_eq!(method(&f, "C", "doc").body, MethodBody::Empty);
+        assert_eq!(
+            method(&f, "C", "forward").body,
+            MethodBody::SuperCall { returns: true, target: "run".into(), args: vec!["x".into()] }
+        );
+        assert_eq!(
+            method(&f, "C", "call").body,
+            MethodBody::SuperCall { returns: false, target: "run".into(), args: vec![] }
+        );
+        assert_eq!(method(&f, "C", "other").body, MethodBody::Other);
+    }
+
+    #[test]
+    fn decorators_are_their_names_and_semantics() {
+        let f = facts(
+            "from abc import abstractmethod\nfrom typing import override\n\nclass C:\n    @abstractmethod\n    def a(self):\n        pass\n\n    @override\n    def b(self):\n        pass\n\n    @functools.cache\n    def c(self):\n        pass\n",
+        );
+        assert!(method(&f, "C", "a").abstract_method);
+        assert!(!method(&f, "C", "a").override_decorated);
+        assert!(method(&f, "C", "b").override_decorated);
+        assert!(!method(&f, "C", "c").override_decorated);
+    }
+
+    #[test]
+    fn override_of_another_library_is_not_typing_override() {
+        let f = facts("from mylib import override\n\nclass C:\n    @override\n    def a(self):\n        pass\n");
+        assert!(!method(&f, "C", "a").override_decorated);
+    }
+
+    #[test]
+    fn aliased_override_and_qualified_forms_are_recognised() {
+        let f = facts(
+            "from typing import override as ov\n\nclass C:\n    @ov\n    def a(self):\n        pass\n\nclass D:\n    @typing_extensions.override\n    def b(self):\n        pass\n",
+        );
+        assert!(method(&f, "C", "a").override_decorated);
+        assert!(method(&f, "D", "b").override_decorated);
+    }
+
+    #[test]
+    fn nested_classes_and_other_languages() {
+        let f = facts("class Outer:\n    class Inner:\n        def m(self):\n            pass\n");
+        let names: Vec<&str> = f.classes.iter().map(|c| c.name.as_str()).collect();
+        assert_eq!(names, ["Outer", "Inner"]);
+        let other = SYNTAX.get_or_init(Syntax::new).python_facts(&LanguageId::new("rust"), "class C {}");
+        assert_eq!(other.classes.len(), 0);
+    }
+}
@@ -41,20 +41,44 @@ pub struct ClientHandler {
    generation: u64,
 }

+/// The diagnostics in `items` (a JSON array) that deserialize. A server's malformed one is
+/// skipped with a warning, so the rest of the file's problems still show.
+pub(crate) fn lenient_diagnostics(server: &str, items: Value) -> Vec<lsp::Diagnostic> {
+    let Value::Array(items) = items else { return Vec::new() };
+    let mut skipped = 0usize;
+    let parsed: Vec<lsp::Diagnostic> = items
+        .into_iter()
+        .filter_map(|mut item| {
+            crate::virtual_doc::normalize_uris(&mut item);
+            match serde_json::from_value(item) {
+                Ok(diagnostic) => Some(diagnostic),
+                Err(_) => {
+                    skipped += 1;
+                    None
+                }
+            }
+        })
+        .collect();
+    if skipped > 0 {
+        tracing::warn!("{server}: skipped {skipped} malformed diagnostic(s)");
+    }
+    parsed
+}
+
 impl ClientHandler {
    pub fn new(mgr: Weak<LspManager>, server: Arc<Server>, generation: u64) -> Self {
        Self { mgr, server, generation }
    }

    fn encoding(&self) -> Encoding {
-        self.server.running_gen(self.generation).map(|r| r.caps.read().encoding).unwrap_or_default()
+        self.server.initialized_gen(self.generation).map(|r| r.caps.read().encoding).unwrap_or_default()
    }

    /// Cancelling task `task` asks this server instance to stop the work of progress `token`.
    fn cancel_handle(&self, task: TaskId, token: &Value) -> ide_core::task::CancelHandle {
        let (server, generation, token) = (self.server.clone(), self.generation, token.clone());
        ide_core::task::on_cancel(task, move || {
-            if let Some(run) = server.running_gen(generation)
+            if let Some(run) = server.initialized_gen(generation)
                && let Err(e) = run.peer.notify("window/workDoneProgress/cancel", json!({ "token": token }))
            {
                tracing::debug!("{}: cannot cancel progress: {e}", server.name);
@@ -176,7 +200,7 @@ impl ClientHandler {
            loop {
                tokio::time::sleep(PROGRESS_SWEEP).await;
                let Some(mgr) = weak.upgrade() else { return };
-                if server.running_gen(generation).is_none() || !server.has_progress(&token) {
+                if !server.is_live(generation) || !server.has_progress(&token) {
                    return; // the instance is gone, or the task ended normally
                }
                if server.progress_silent(&token, PROGRESS_STALE) {
@@ -218,20 +242,57 @@ impl ClientHandler {
        true
    }

+    /// Ends every running task of a tsserver that died at its heap limit: the process
+    /// behind them is gone, so no `end` will ever arrive. Without this the tasks sit
+    /// as zombies until [`PROGRESS_STALE`] and the server stays "loading", holding
+    /// empty answers back for [`LOADING_WAIT`] — while vtsls already restarts
+    /// tsserver, which re-reports its own loading.
+    fn tsserver_died(&self, mgr: &LspManager) {
+        let events: Vec<IdeEvent> = {
+            let mut progress = self.server.progress.lock();
+            progress
+                .drain()
+                .map(|(_, p)| IdeEvent::Task {
+                    id: p.task,
+                    title: p.title,
+                    message: p.message,
+                    fraction: Some(1.0),
+                    done: true,
+                    cancellable: false,
+                })
+                .collect()
+        };
+        let ended = !events.is_empty();
+        for event in events {
+            self.server.emit(mgr.sink(), event);
+        }
+        if ended {
+            self.server.refresh_busy_status(mgr.sink());
+            self.server.progress_ended();
+        }
+        self.server.set_loading(mgr.sink(), false);
+    }
+
    fn publish_diagnostics(&self, mgr: &LspManager, params: Value) {
        // Problems come only from servers used for `diagnostics`.
-        if self.server.running_gen(self.generation).is_some_and(|run| !run.caps.read().restriction.diagnostics()) {
+        if self.server.initialized_gen(self.generation).is_some_and(|run| !run.caps.read().restriction.diagnostics()) {
            return;
        }
        let mut params = params;
        crate::virtual_doc::normalize_uris(&mut params);
-        let params: lsp::PublishDiagnosticsParams = match serde_json::from_value(params) {
+        // One malformed diagnostic must not take the others of the file with it.
+        let raw = params.get_mut("diagnostics").map(Value::take);
+        if let Some(fields) = params.as_object_mut() {
+            fields.insert("diagnostics".into(), json!([]));
+        }
+        let mut params: lsp::PublishDiagnosticsParams = match serde_json::from_value(params) {
            Ok(p) => p,
            Err(e) => {
                tracing::debug!("{}: bad publishDiagnostics: {e}", self.server.name);
                return;
            }
        };
+        params.diagnostics = lenient_diagnostics(&self.server.name, raw.unwrap_or(Value::Null));
        let Some(path) = uri_to_path(params.uri.as_str())
            .or_else(|| crate::notebook::is_cell_uri(params.uri.as_str()).then(|| PathBuf::from(params.uri.as_str())))
        else {
@@ -410,6 +471,10 @@ impl Handler for ClientHandler {
                let text = params.get("message").and_then(Value::as_str).unwrap_or_default();
                if self.server.config.tsserver_project && tsserver_ran_out_of_memory(text) {
                    tracing::warn!("[{}] {text}", self.server.name);
+                    // The tasks of the dead tsserver never see their `end`: end them now
+                    // instead of letting them sit as zombies until the stale window, and
+                    // stop holding queries back — the restarted instance re-reports.
+                    self.tsserver_died(&mgr);
                    if mgr.first_message(&self.server.name, TSSERVER_OUT_OF_MEMORY) {
                        mgr.sink().emit(IdeEvent::Notify {
                            level: NotifyLevel::Error,
@@ -445,7 +510,7 @@ impl Handler for ClientHandler {
                crate::kotlin_lsp::record_import_state(&self.server, self.generation, &params)
            }
            "language/status" if self.server.name == "jdtls" && params["type"] == "ServiceReady" => {
-                if self.server.running_gen(self.generation).is_some() {
+                if self.server.initialized_gen(self.generation).is_some() {
                    self.server.set_java_ready();
                }
                mgr.java_import_ready(self.server.clone(), self.generation);
@@ -567,7 +632,12 @@ fn merge(base: &mut Value, layer: Value) {

 #[cfg(test)]
 mod tests {
-    use super::tsserver_ran_out_of_memory;
+    use super::*;
+    use crate::server::Progress;
+    use ide_core::event::SharedSink;
+    use ide_core::{LanguageId, TaskId};
+    use std::path::PathBuf;
+    use std::sync::{Arc, Mutex};

    #[test]
    fn tsserver_aborts_are_out_of_memory() {
@@ -579,4 +649,85 @@ mod tests {
        assert!(!tsserver_ran_out_of_memory("Code: 134."));
        assert!(tsserver_ran_out_of_memory("[error] TSServer exited. Code: 134. Signal: null\n"));
    }
+
+    /// A vtsls server with two running tasks, one marked stalled, and `loading` set:
+    /// the state a tsserver OOM leaves behind.
+    fn loaded_vtsls(events: Arc<Mutex<Vec<IdeEvent>>>) -> (Arc<LspManager>, Arc<crate::server::Server>) {
+        let sink: SharedSink = {
+            let events = events.clone();
+            Arc::new(move |event: IdeEvent| events.lock().unwrap().push(event))
+        };
+        let languages = Arc::new(ide_language::LanguageRegistry::from_configs(vec![]));
+        let mgr = LspManager::new(PathBuf::from("/p"), languages, sink);
+        let cfg: ide_language::LanguageServerConfig =
+            toml::from_str("name = \"vtsls\"\ncommand = \"vtsls\"\ntsserver-project = true").unwrap();
+        let server = Arc::new(crate::server::Server::new(cfg, PathBuf::from("/p"), LanguageId::new("vue")));
+        server.progress.lock().insert(
+            "loading".into(),
+            Progress {
+                task: TaskId::next(),
+                title: "Initializing 'tsconfig.json'".into(),
+                message: None,
+                cancel: None,
+                last: tokio::time::Instant::now(),
+                fraction: Some(0.1),
+                stalled: false,
+            },
+        );
+        server.progress.lock().insert(
+            "stuck".into(),
+            Progress {
+                task: TaskId::next(),
+                title: "Analyzing 'index.vue' and its dependencies".into(),
+                message: None,
+                cancel: None,
+                last: tokio::time::Instant::now(),
+                fraction: Some(0.2),
+                stalled: true,
+            },
+        );
+        let quiet: SharedSink = Arc::new(|_: IdeEvent| {});
+        server.set_loading(&quiet, true);
+        (mgr, server)
+    }
+
+    #[test]
+    fn tsserver_dying_ends_every_task_and_the_loading_state() {
+        let events = Arc::new(Mutex::new(Vec::new()));
+        let (mgr, server) = loaded_vtsls(events.clone());
+        let handler = ClientHandler::new(Arc::downgrade(&mgr), server.clone(), 0);
+
+        handler.tsserver_died(&mgr);
+
+        // Both tasks ended (done: true), including the stalled one; none left running.
+        let tasks: Vec<_> = events
+            .lock()
+            .unwrap()
+            .iter()
+            .filter_map(|e| match e {
+                IdeEvent::Task { title, done, .. } => Some((title.clone(), *done)),
+                _ => None,
+            })
+            .collect();
+        assert_eq!(tasks.len(), 2, "{tasks:?}");
+        assert!(tasks.iter().all(|(_, done)| *done), "{tasks:?}");
+        assert!(server.progress.lock().is_empty());
+        assert!(!server.is_loading());
+        assert!(!server.is_busy());
+    }
+
+    #[test]
+    fn tsserver_dying_without_tasks_only_clears_loading() {
+        let events = Arc::new(Mutex::new(Vec::new()));
+        let (mgr, server) = loaded_vtsls(events.clone());
+        server.progress.lock().clear();
+        let handler = ClientHandler::new(Arc::downgrade(&mgr), server.clone(), 0);
+
+        handler.tsserver_died(&mgr);
+
+        assert!(events.lock().unwrap().is_empty());
+        assert!(!server.is_loading());
+        // A status event may be published, but no task events.
+        assert!(server.progress.lock().is_empty());
+    }
 }
@@ -103,7 +103,7 @@ impl Launcher for ProcessLauncher {
            // A plugin's server: the approved program, unchanged since.
            Some(pin) => Some(pin.verify().map_err(LaunchError::Failed)?.to_path_buf()),
            None => ide_core::tool_path::find_command(&config.command, &search, root)
-                .and_then(|b| resolve_rustup_proxy(&config.command, b))
+                .and_then(|b| resolve_rustup_proxy(&config.command, b, root))
                .and_then(|b| reject_dead_shim(b, &search, root)),
        };
        let mut env: Vec<(String, String)> = vec![("PATH".into(), search.to_string_lossy().into_owned())];
@@ -208,34 +208,16 @@ fn reject_dead_shim(binary: PathBuf, search: &OsStr, root: &Path) -> Option<Path
 /// toolchain lacks the component (common for rust-analyzer). In that case use
 /// the newest installed toolchain that ships the binary; with none, the tool is
 /// missing (an install hint, not a server that crashes on every restart).
-fn resolve_rustup_proxy(command: &str, binary: PathBuf) -> Option<PathBuf> {
+/// The probe runs in the project's root, where a `rust-toolchain.toml` picks the toolchain.
+fn resolve_rustup_proxy(command: &str, binary: PathBuf, root: &Path) -> Option<PathBuf> {
    let is_proxy = binary.parent().is_some_and(|d| d.ends_with(".cargo/bin"));
    if !is_proxy || command.contains('/') {
        return Some(binary);
    }
-    let works = ide_core::process::prepare(&mut std::process::Command::new(&binary))
-        .arg("--version")
-        .stdin(std::process::Stdio::null())
-        .stdout(std::process::Stdio::null())
-        .stderr(std::process::Stdio::null())
-        .status()
-        .is_ok_and(|s| s.success());
-    if works {
+    if proxy_works(&binary, root) {
        return Some(binary);
    }
-    let toolchains = std::env::var_os("RUSTUP_HOME")
-        .map(PathBuf::from)
-        .or_else(|| std::env::var_os("HOME").map(|h| PathBuf::from(h).join(".rustup")))
-        .map(|h| h.join("toolchains"));
-    let mut candidates: Vec<(std::time::SystemTime, PathBuf)> = toolchains
-        .and_then(|dir| std::fs::read_dir(dir).ok())
-        .into_iter()
-        .flatten()
-        .flatten()
-        .map(|e| e.path().join("bin").join(command))
-        .filter(|p| p.is_file())
-        .filter_map(|p| Some((p.metadata().ok()?.modified().ok()?, p)))
-        .collect();
+    let mut candidates = rustup_home().map(|h| toolchain_binaries(&h.join("toolchains"), command)).unwrap_or_default();
    // Prefer stable-looking toolchains, then the most recently installed.
    candidates.sort_by_key(|(mtime, p)| (!p.to_string_lossy().contains("nightly"), *mtime));
    match candidates.pop() {
@@ -250,6 +232,57 @@ fn resolve_rustup_proxy(command: &str, binary: PathBuf) -> Option<PathBuf> {
    }
 }

+/// Whether the proxy runs for the toolchain active in `root`. A probe that hangs or can't
+/// be waited for counts as working: the real start decides.
+fn proxy_works(binary: &Path, root: &Path) -> bool {
+    let Ok(mut child) = ide_core::process::prepare(&mut std::process::Command::new(binary))
+        .arg("--version")
+        .current_dir(root)
+        .stdin(std::process::Stdio::null())
+        .stdout(std::process::Stdio::null())
+        .stderr(std::process::Stdio::null())
+        .spawn()
+    else {
+        return true;
+    };
+    let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+    loop {
+        match child.try_wait() {
+            Ok(Some(status)) => return status.success(),
+            Ok(None) if std::time::Instant::now() < deadline => {
+                std::thread::sleep(std::time::Duration::from_millis(20))
+            }
+            _ => {
+                let _ = child.kill();
+                return true;
+            }
+        }
+    }
+}
+
+/// Where rustup keeps its toolchains: `RUSTUP_HOME`, else `.rustup` in the user's home
+/// (`HOME`, which a GUI app on Windows doesn't have, or `USERPROFILE`).
+fn rustup_home() -> Option<PathBuf> {
+    std::env::var_os("RUSTUP_HOME").map(PathBuf::from).or_else(|| {
+        let home = std::env::var_os("HOME").or_else(|| std::env::var_os("USERPROFILE"))?;
+        Some(PathBuf::from(home).join(".rustup"))
+    })
+}
+
+/// The `command` binary (with the platform's executable suffix) of every toolchain in
+/// `toolchains`, with its modification time.
+fn toolchain_binaries(toolchains: &Path, command: &str) -> Vec<(std::time::SystemTime, PathBuf)> {
+    let file = format!("{command}{}", std::env::consts::EXE_SUFFIX);
+    std::fs::read_dir(toolchains)
+        .into_iter()
+        .flatten()
+        .flatten()
+        .map(|e| e.path().join("bin").join(&file))
+        .filter(|p| p.is_file())
+        .filter_map(|p| Some((p.metadata().ok()?.modified().ok()?, p)))
+        .collect()
+}
+
 /// Workspace root for `file`: the outermost ancestor within `project_root`
 /// containing a root marker (so a Cargo/npm workspace gets one server, not one
 /// per member), else `project_root`. `None` when `file` is outside the project.
@@ -363,7 +396,24 @@ mod proxy_tests {
    #[test]
    fn non_proxy_binaries_are_kept() {
        let p = PathBuf::from("/usr/bin/true");
-        assert_eq!(resolve_rustup_proxy("true", p.clone()), Some(p));
+        assert_eq!(resolve_rustup_proxy("true", p.clone(), Path::new(".")), Some(p));
+    }
+
+    /// The binary is `rust-analyzer.exe` on Windows: a lookup of the bare name found nothing there.
+    #[test]
+    fn toolchain_binaries_carry_the_platform_executable_suffix() {
+        let tmp = tempfile::tempdir().unwrap();
+        let file = format!("rust-analyzer{}", std::env::consts::EXE_SUFFIX);
+        for toolchain in ["stable-x86_64", "nightly-x86_64"] {
+            std::fs::create_dir_all(tmp.path().join(toolchain).join("bin")).unwrap();
+        }
+        std::fs::write(tmp.path().join("stable-x86_64/bin").join(&file), "").unwrap();
+        // Another tool, and a bare name without the suffix where one is required.
+        std::fs::write(tmp.path().join("nightly-x86_64/bin").join("rustfmt"), "").unwrap();
+        let found = toolchain_binaries(tmp.path(), "rust-analyzer");
+        assert_eq!(found.len(), 1);
+        assert_eq!(found[0].1, tmp.path().join("stable-x86_64/bin").join(&file));
+        assert!(toolchain_binaries(&tmp.path().join("missing"), "rust-analyzer").is_empty());
    }

    /// Exercises the real machine setup when a broken rustup proxy is present.
@@ -372,7 +422,7 @@ mod proxy_tests {
    fn broken_rustup_proxy_falls_back_to_a_toolchain() {
        let home = PathBuf::from(std::env::var_os("HOME").unwrap());
        let proxy = home.join(".cargo/bin/rust-analyzer");
-        let resolved = resolve_rustup_proxy("rust-analyzer", proxy.clone()).unwrap();
+        let resolved = resolve_rustup_proxy("rust-analyzer", proxy.clone(), Path::new(".")).unwrap();
        eprintln!("resolved: {}", resolved.display());
        assert_ne!(resolved, proxy);
    }
@@ -343,6 +343,10 @@ impl<T> Outcome<T> {
 /// How often a rename the server withdrew (`ContentModified`) is asked, and the pause between.
 const RENAME_ATTEMPTS: u32 = 5;
 const RENAME_RETRY_DELAY: std::time::Duration = std::time::Duration::from_millis(300);
+/// How often a semantic tokens, inlay hints or code lens request the server withdrew
+/// (`ContentModified`) is asked again, and the pause between.
+const STALE_RETRIES: u32 = 2;
+const STALE_RETRY_DELAY: std::time::Duration = std::time::Duration::from_millis(150);

 /// Implementation requests of one line-marker pass in flight at once.
 const IMPLEMENTATION_CONCURRENCY: usize = 4;
@@ -654,8 +658,9 @@ impl LspManager {
    }

    /// The servers serving `path`: every regular one, and each `fallback` one
-    /// only while all servers listed before it are missing. One that requires a
-    /// root marker serves only files below one, and stands in for no other.
+    /// only while all servers listed before it have given up (missing, not
+    /// launchable, or crashed for good). One that requires a root marker serves
+    /// only files below one, and stands in for no other.
    fn servers_for(&self, language: &LanguageId, path: &Path) -> Vec<Arc<Server>> {
        if let Some(servers) = self.arduino_servers(language, path) {
            return servers;
@@ -672,7 +677,7 @@ impl LspManager {
                continue;
            }
            let server = self.server_for(sc, language, path);
-            available_before |= !sc.require_root_marker && server.status() != ide_core::event::ServerStatus::Missing;
+            available_before |= !sc.require_root_marker && !server.gave_up();
            out.push(server);
        }
        out
@@ -748,9 +753,14 @@ impl LspManager {
        if self.shutting_down.load(Ordering::Acquire) || !self.execution_allowed.load(Ordering::Acquire) {
            return;
        }
+        // A server dropped meanwhile (disabled in settings, shadowed by another) must not come
+        // back as a process nothing lists, serves or stops: a crash backoff can outlive it.
+        if !self.servers.lock().iter().any(|s| s.id == server.id) {
+            return;
+        }
        let workspace = is_local_jdtls(&server.config).then(|| self.jdtls_workspace_state());
        if let Some(state) = &workspace {
-            if state.transitioning || !self.servers.lock().iter().any(|s| s.id == server.id) {
+            if state.transitioning {
                return;
            }
            let (shared, roots) = self.desired_jdtls_workspace();
@@ -861,24 +871,28 @@ impl LspManager {
            }
            Err(LaunchError::Config(message)) => {
                tracing::warn!("{}: {message}", server.name);
-                server.fail_start(
+                if server.fail_start(
                    generation,
                    Conn::Failed,
                    &self.sink,
                    ide_core::event::ServerStatus::Misconfigured,
                    Some(message),
-                );
+                ) {
+                    self.attach_fallbacks();
+                }
                return;
            }
            Err(LaunchError::Failed(message)) => {
                tracing::warn!("{}: {message}", server.name);
-                server.fail_start(
+                if server.fail_start(
                    generation,
                    Conn::Failed,
                    &self.sink,
                    ide_core::event::ServerStatus::Crashed,
                    Some(message),
-                );
+                ) {
+                    self.attach_fallbacks();
+                }
                return;
            }
        };
@@ -920,9 +934,18 @@ impl LspManager {
            }
            Err(e) => {
                tracing::warn!("{}: initialize failed: {e}", server.name);
-                if matches!(e, RpcError::Closed) {
+                match e {
                    // The server is exiting: let it, so the crash report has its exit code and last output.
-                    let _ = tokio::time::timeout(Duration::from_secs(3), peer.closed()).await;
+                    RpcError::Closed => {
+                        let _ = tokio::time::timeout(Duration::from_secs(3), peer.closed()).await;
+                    }
+                    RpcError::Timeout => {
+                        server.set_start_error(
+                            generation,
+                            format!("it did not answer initialize within {} s", INITIALIZE_TIMEOUT.as_secs()),
+                        );
+                    }
+                    e => server.set_start_error(generation, format!("initialize failed ({e})")),
                }
                Self::kill_peer(&server, &peer).await;
                // Treated like a crash so transient failures retry with backoff.
@@ -1008,11 +1031,15 @@ impl LspManager {
            self.forget(std::slice::from_ref(&server));
            return;
        }
-        if let Some(delay) = delay {
-            tokio::time::sleep(delay).await;
-            if server.is_idle_gen(generation) {
-                self.ensure_started(&server);
+        match delay {
+            Some(delay) => {
+                tokio::time::sleep(delay).await;
+                if server.is_idle_gen(generation) {
+                    self.ensure_started(&server);
+                }
            }
+            // Gave up (crashed repeatedly, or its build expired): the fallbacks it hid take over.
+            None => self.attach_fallbacks(),
        }
    }

@@ -1458,6 +1485,28 @@ impl LspManager {
        result
    }

+    /// [`Self::call`], asked again when the server withdrew the answer because the text changed
+    /// (`ContentModified`, which arrives as a cancellation as no cancel token is passed).
+    /// The client advertises `retryOnContentModified` for the methods that use it.
+    async fn call_retrying<P: Serialize + Clone, R: DeserializeOwned>(
+        &self,
+        t: &Target,
+        method: &str,
+        params: P,
+        timeout: Duration,
+    ) -> IdeResult<R> {
+        let mut attempt = 0;
+        loop {
+            match self.call(t, method, params.clone(), None, timeout).await {
+                Err(e) if e.kind == ErrorKind::Cancelled && attempt < STALE_RETRIES => {
+                    attempt += 1;
+                    tokio::time::sleep(STALE_RETRY_DELAY).await;
+                }
+                result => return result,
+            }
+        }
+    }
+
    // ---- features ----
    pub async fn completion(
        &self,
@@ -2892,11 +2941,10 @@ impl LspManager {
            async move {
                (
                    t,
-                    self.call::<_, Option<Vec<lsp::InlayHint>>>(
+                    self.call_retrying::<_, Option<Vec<lsp::InlayHint>>>(
                        t,
                        "textDocument/inlayHint",
                        params,
-                        None,
                        DEFAULT_TIMEOUT,
                    )
                    .await,
@@ -2927,7 +2975,8 @@ impl LspManager {
            self.ready_targets(&snap.servers, |c| c.semantic_tokens_full() && c.semantic_legend.is_some()).await;
        let Some(t) = targets.first() else { return Ok(None) };
        let params = json!({ "textDocument": snap.ident() });
-        let r: Option<Value> = self.call(t, "textDocument/semanticTokens/full", params, None, DEFAULT_TIMEOUT).await?;
+        let r: Option<Value> =
+            self.call_retrying(t, "textDocument/semanticTokens/full", params, DEFAULT_TIMEOUT).await?;
        let Some(data) = r.as_ref().and_then(|v| v.get("data")).and_then(Value::as_array) else { return Ok(None) };
        let data: Vec<i64> = data.iter().map(|n| n.as_i64().unwrap_or(0)).collect();
        let (enc, legend) = {
@@ -2948,7 +2997,7 @@ impl LspManager {
            let params = json!({ "textDocument": snap.ident() });
            async move {
                let lenses = self
-                    .call::<_, Option<Vec<lsp::CodeLens>>>(t, "textDocument/codeLens", params, None, DEFAULT_TIMEOUT)
+                    .call_retrying::<_, Option<Vec<lsp::CodeLens>>>(t, "textDocument/codeLens", params, DEFAULT_TIMEOUT)
                    .await?;
                let lenses = lenses.unwrap_or_default();
                if !t.caps().has_sub("codeLensProvider", "resolveProvider") {
@@ -3097,6 +3146,21 @@ impl LspManager {
        Ok(CallHierarchy { items: out, incomplete })
    }

+    /// The type at `pos` as the server's type hierarchy names it (with its `detail`, the
+    /// package for Java); `None` when there is no type there.
+    pub async fn prepare_type_hierarchy(&self, doc: DocId, pos: Pos) -> IdeResult<Option<HierarchyItem>> {
+        let (snap, targets) = self.doc_targets(doc, "type hierarchy", |c| c.has("typeHierarchyProvider")).await?;
+        let t = &targets[0];
+        let items: Option<Vec<serde_json::Value>> =
+            self.call(t, "textDocument/prepareTypeHierarchy", snap.pos_params(t, pos), None, DEFAULT_TIMEOUT).await?;
+        let conv = self.conv(t.enc());
+        Ok(items
+            .unwrap_or_default()
+            .iter()
+            .filter_map(convert::type_item_from_json)
+            .find_map(|i| convert::type_item(&conv, &i)))
+    }
+
    pub async fn type_hierarchy(
        &self,
        doc: DocId,
@@ -3855,31 +3919,41 @@ impl LspManager {
                languages: s.languages(),
                status: s.status(),
                pid: s.running().and_then(|r| r.peer.pid()),
+                label: s.display_name(),
            })
            .collect()
    }

    pub async fn restart(&self, server: ide_core::ServerId) -> IdeResult<()> {
-        let _reconfigure = self.reconfigure_lock.lock().await;
-        let s = self
-            .servers
-            .lock()
-            .iter()
-            .find(|s| s.id == server)
-            .cloned()
-            .ok_or_else(|| IdeError::not_found(format!("unknown language server {server}")))?;
-        if !s.root.is_dir() {
-            return Err(IdeError::unavailable(format!(
-                "the workspace root of {} is gone: {}",
-                s.name,
-                s.root.display()
-            )));
-        }
-        self.stop_instance(&s, false).await;
-        s.reset_for_restart();
-        self.ensure_started(&s);
+        let s = {
+            // Only the restart itself holds the lock: a start can take minutes (a Gradle or
+            // Maven import), and `reconfigure` and `shutdown_all` wait for it.
+            let _reconfigure = self.reconfigure_lock.lock().await;
+            let s = self
+                .servers
+                .lock()
+                .iter()
+                .find(|s| s.id == server)
+                .cloned()
+                .ok_or_else(|| IdeError::not_found(format!("unknown language server {server}")))?;
+            if !s.root.is_dir() {
+                return Err(IdeError::unavailable(format!(
+                    "the workspace root of {} is gone: {}",
+                    s.name,
+                    s.root.display()
+                )));
+            }
+            self.stop_instance(&s, false).await;
+            s.reset_for_restart();
+            self.ensure_started(&s);
+            // Started again: it shadows the fallbacks that took over while it was down.
+            self.detach_shadowed_fallbacks().await;
+            s
+        };
        match s.wait_ready(Duration::from_secs(60)).await {
            Some(_) => Ok(()),
+            // Still importing the project: the restart worked, the server is just not ready yet.
+            None if s.is_starting() => Ok(()),
            None => {
                Err(IdeError::unavailable(s.status_message().unwrap_or_else(|| format!("{} failed to start", s.name))))
            }
@@ -136,7 +136,8 @@ fn source_entry(sources: &Path, class: &str, encoding: Option<&str>) -> Option<(
            return Some((entry.clone(), text));
        }
    }
-    // A facade renamed with `@file:JvmName("…")`.
+    // A facade renamed with `@file:JvmName("…")`, or a class declared in a file named otherwise
+    // (`UserDto` in `Models.kt`).
    let kotlin_files: Vec<String> = zip
        .file_names()
        .filter_map(|n| n.ok().map(|n| n.into_owned()))
@@ -145,7 +146,7 @@ fn source_entry(sources: &Path, class: &str, encoding: Option<&str>) -> Option<(
    let jvm_name = format!("@file:JvmName(\"{outer}\")");
    for entry in kotlin_files {
        if let Some(text) = read(&entry)
-            && text.text.contains(&jvm_name)
+            && (text.text.contains(&jvm_name) || declares_type(&text.text, outer))
        {
            return Some((entry, text));
        }
@@ -153,6 +154,26 @@ fn source_entry(sources: &Path, class: &str, encoding: Option<&str>) -> Option<(
    None
 }

+/// Whether `text` declares a type called `name` (`class`, `interface`, `object`, `typealias`):
+/// how a Kotlin file that is not named after its class is recognised.
+fn declares_type(text: &str, name: &str) -> bool {
+    const KINDS: [&str; 4] = ["class", "interface", "object", "typealias"];
+    text.lines().any(|line| {
+        let line = line.trim_start();
+        if line.starts_with("//") || line.starts_with("/*") || line.starts_with('*') {
+            return false;
+        }
+        let mut words =
+            line.split(|c: char| !(c.is_alphanumeric() || c == '_' || c == '$' || c == '`')).filter(|w| !w.is_empty());
+        let mut previous = words.next();
+        words.any(|word| {
+            let hit = previous.is_some_and(|p| KINDS.contains(&p)) && word.trim_matches('`') == name;
+            previous = Some(word);
+            hit
+        })
+    })
+}
+
 /// Where `name` is declared in a Kotlin or Java source `text` (the start of the
 /// name), else the start of the file.
 pub(crate) fn declaration_range(text: &str, name: &str) -> Range {
@@ -245,6 +266,22 @@ pub(crate) fn folder_class(uri: &str) -> Option<(String, String)> {
    Some((package.replace('.', "/"), name.to_owned()))
 }

+/// Kotlin sources larger than this are not searched for a class declared in a file named otherwise.
+const MAX_SOURCE: u64 = 1 << 20;
+
+/// The files of the project's source trees: build output and ignored files are skipped.
+fn walk_sources(root: &Path) -> impl Iterator<Item = ignore::DirEntry> {
+    ignore::WalkBuilder::new(root)
+        .filter_entry(|e| {
+            let output = matches!(e.file_name().to_str(), Some("target" | "build" | "out" | "node_modules"));
+            // A package may be named `build`: only outside source trees is it output.
+            !output || e.path().components().any(|c| c.as_os_str() == "src")
+        })
+        .build()
+        .flatten()
+        .filter(|e| e.file_type().is_some_and(|t| t.is_file()))
+}
+
 /// The project's source of `class` (`Name`, `Outer$Inner`, `FileKt`) in `package`
 /// (`/`-separated): a `.kt` / `.java` file of that name declaring the package. Build
 /// output and ignored files are skipped.
@@ -255,19 +292,24 @@ pub(crate) fn project_class_source(root: &Path, package: &str, class: &str) -> O
        names.push(format!("{file}.kt"));
    }
    let package = package.replace('/', ".");
-    let mut found: Vec<PathBuf> = ignore::WalkBuilder::new(root)
-        .filter_entry(|e| {
-            let output = matches!(e.file_name().to_str(), Some("target" | "build" | "out" | "node_modules"));
-            // A package may be named `build`: only outside source trees is it output.
-            !output || e.path().components().any(|c| c.as_os_str() == "src")
-        })
-        .build()
-        .flatten()
-        .filter(|e| e.file_type().is_some_and(|t| t.is_file()))
+    let mut found: Vec<PathBuf> = walk_sources(root)
        .filter(|e| e.file_name().to_str().is_some_and(|n| names.iter().any(|name| name == n)))
        .map(|e| e.into_path())
        .filter(|p| std::fs::read_to_string(p).is_ok_and(|text| declared_package(&text) == package))
        .collect();
+    // A class declared in a file named otherwise (`UserDto` in `Models.kt`).
+    if found.is_empty() {
+        found = walk_sources(root)
+            .filter(|e| {
+                e.path().extension().is_some_and(|x| x == "kt") && e.metadata().is_ok_and(|m| m.len() <= MAX_SOURCE)
+            })
+            .map(|e| e.into_path())
+            .filter(|p| {
+                std::fs::read_to_string(p)
+                    .is_ok_and(|text| declared_package(&text) == package && declares_type(&text, outer))
+            })
+            .collect();
+    }
    // The directory matching the package first, then by name order.
    found.sort_by_key(|p| {
        let dir = p.parent().map(|d| d.to_string_lossy().replace('\\', "/")).unwrap_or_default();
@@ -358,6 +400,10 @@ mod tests {
                "@file:JvmName(\"BootUtils\")\npackage org.springframework.boot\nfun util() {}",
            ),
            ("org/springframework/boot/Builder.kt", "class Builder"),
+            (
+                "org/springframework/boot/Models.kt",
+                "package org.springframework.boot\n\n// class NotMe\ndata class UserDto(val id: Int)\nenum class Role { A }\ninterface Repo\nobject Registry\ntypealias Ids = List<Int>\n",
+            ),
            ("Root.java", "class Root {}"),
        ];
        jar(&m2.join("spring-boot-3.5.16.jar"), &[]);
@@ -373,6 +419,11 @@ mod tests {
                ("org/springframework/boot/SpringApplication$Running.class", "SpringApplication.java"),
                ("org/springframework/boot/BootUtils.class", "Renamed.kt"),
                ("org/springframework/boot/Builder.class", "Builder.kt"),
+                // Declared in a file that is not named after them.
+                ("org/springframework/boot/UserDto.class", "Models.kt"),
+                ("org/springframework/boot/Role$A.class", "Models.kt"),
+                ("org/springframework/boot/Repo.class", "Models.kt"),
+                ("org/springframework/boot/Registry.class", "Models.kt"),
                ("Root.class", "Root.java"),
            ] {
                let (source_uri, text) =
@@ -385,6 +436,7 @@ mod tests {
                );
            }
            assert!(class_source(&uri("org/springframework/boot/Missing.class"), None).is_none());
+            assert!(class_source(&uri("org/springframework/boot/NotMe.class"), None).is_none(), "only in a comment");
        }
        // No sources jar: nothing to show from here.
        let lone = tmp.path().join("lone/x-1.jar");
@@ -482,7 +534,8 @@ mod tests {
        std::fs::create_dir_all(output.join("test001")).unwrap();
        // As jdtls writes it: the class's source file name in the path, the library's
        // classpath attributes after the folder.
-        let escaped = output.to_string_lossy().replace('/', "\\/");
+        // JDT writes the folder as a portable path, `/` on Windows too, each `/` escaped.
+        let escaped = output.to_string_lossy().replace('\\', "/").replace('/', "\\/");
        let handle = format!("=demo/{escaped}=/ai.openidea.kotlin=/true=/<test001(Db.class");
        let uri = format!("jdt://contents/main-0/test001/Db.kt?{}", utf8_percent_encode(&handle, PATH));
        assert_eq!(folder_class(&uri), Some(("test001".into(), "Db".into())));
@@ -512,6 +565,11 @@ mod tests {
        write("src/main/kotlin/com/x/build/Tool.kt", "package com.x.build\n\nclass Tool\n");
        write("src/main/kotlin/flat/Elsewhere.kt", "");
        write("src/main/kotlin/Loose.kt", "package flat\n\nobject Loose\n");
+        write(
+            "src/main/kotlin/test001/Models.kt",
+            "package test001\n\n// class NotMe\ndata class UserDto(val id: Int)\n",
+        );
+        write("src/main/kotlin/other/Models.kt", "package other\n\ndata class UserDto(val name: String)\n");
        let source = |package: &str, class: &str| {
            project_class_source(root, package, class).map(|p| p.strip_prefix(root).unwrap().to_owned())
        };
@@ -522,6 +580,10 @@ mod tests {
        assert_eq!(source("com/x/build", "Tool"), Some(PathBuf::from("src/main/kotlin/com/x/build/Tool.kt")));
        assert_eq!(source("flat", "Loose"), Some(PathBuf::from("src/main/kotlin/Loose.kt")), "any directory");
        assert_eq!(source("test001", "Missing"), None);
+        // Declared in a file named otherwise: the one of the package, not another package's.
+        assert_eq!(source("test001", "UserDto"), Some(PathBuf::from("src/main/kotlin/test001/Models.kt")));
+        assert_eq!(source("other", "UserDto"), Some(PathBuf::from("src/main/kotlin/other/Models.kt")));
+        assert_eq!(source("test001", "NotMe"), None, "only in a comment");
        assert_eq!(declared_package("package a.b.c;\n"), "a.b.c");
        assert_eq!(declared_package("class A"), "");
    }
@@ -166,13 +166,10 @@ impl LspManager {
            let result_id = report.get("resultId").and_then(Value::as_str).map(str::to_owned);
            let items = match report.get("kind").and_then(Value::as_str) {
                Some("unchanged") => None,
-                _ => match serde_json::from_value(report.get("items").cloned().unwrap_or(json!([]))) {
-                    Ok(items) => Some(items),
-                    Err(e) => {
-                        tracing::debug!("{}: bad textDocument/diagnostic report: {e}", t.server.name);
-                        return;
-                    }
-                },
+                _ => Some(crate::handler::lenient_diagnostics(
+                    &t.server.name,
+                    report.get("items").cloned().unwrap_or(json!([])),
+                )),
            };
            let shown = t.server.set_pulled(t.path.clone(), result_id, items);
            let enc = t.run.caps.read().encoding;
@@ -112,8 +112,11 @@ pub struct Server {
    status: Mutex<(ServerStatus, Option<String>)>,
    /// Consecutive crashes of short-lived instances.
    crashes: Mutex<usize>,
-    /// When the current instance was launched.
+    /// When the current instance became ready: only time spent running counts as uptime,
+    /// not the time spent starting (an `initialize` that hangs for minutes is not a stable run).
    started: Mutex<Option<Instant>>,
+    /// Why the current instance's `initialize` failed, for the crash report.
+    start_error: Mutex<Option<(u64, String)>>,
    stderr: Mutex<VecDeque<String>>,
    pub progress: Mutex<HashMap<String, Progress>>,
    /// What the editor shows per path: the pushed and the pulled diagnostics together.
@@ -177,6 +180,7 @@ impl Server {
            status: Mutex::new((ServerStatus::Stopped, None)),
            crashes: Mutex::new(0),
            started: Mutex::new(None),
+            start_error: Mutex::new(None),
            stderr: Mutex::new(VecDeque::new()),
            progress: Mutex::new(HashMap::new()),
            diagnostics: Mutex::new(HashMap::new()),
@@ -213,6 +217,11 @@ impl Server {
        config
    }

+    /// The configured server's display name for the current (or last) instance.
+    pub fn display_name(&self) -> Option<String> {
+        self.effective.lock().as_ref().and_then(|c| c.display_name.clone())
+    }
+
    pub fn set_effective_config(&self, generation: u64, config: LanguageServerConfig) {
        let st = self.state.lock();
        if st.generation == generation && matches!(st.conn, Conn::Starting | Conn::Ready(_)) {
@@ -252,7 +261,8 @@ impl Server {
        st.conn = Conn::Starting;
        st.restarting = false;
        *self.start_cancel.lock() = CancellationToken::new();
-        *self.started.lock() = Some(Instant::now());
+        *self.started.lock() = None;
+        *self.start_error.lock() = None;
        // A crash report quotes only this instance's output, not its predecessors'.
        self.stderr.lock().clear();
        self.import_state.send_replace(None);
@@ -300,9 +310,15 @@ impl Server {
        }
        st.conn = Conn::Ready(run);
        *self.initializing.lock() = None;
+        *self.started.lock() = Some(Instant::now());
        true
    }

+    /// Records why instance `generation` failed to initialize, so its crash report says so.
+    pub fn set_start_error(&self, generation: u64, reason: String) {
+        *self.start_error.lock() = Some((generation, reason));
+    }
+
    /// Wakes requests waiting for the instance (after status and documents are in place).
    pub fn announce_ready(&self, generation: u64) {
        let st = self.state.lock();
@@ -322,6 +338,13 @@ impl Server {
        matches!(self.state.lock().conn, Conn::Starting)
    }

+    /// The server will not run until something changes: its binary is missing, its
+    /// configuration can't launch it, or it crashed too often (or its build expired).
+    /// Servers that crashed and are about to restart are not given up on.
+    pub fn gave_up(&self) -> bool {
+        matches!(self.state.lock().conn, Conn::Missing | Conn::Failed)
+    }
+
    /// The instance told `initialized`, ready or not.
    pub fn instance(&self) -> Option<Running> {
        self.running().or_else(|| self.initializing.lock().clone())
@@ -346,6 +369,13 @@ impl Server {
        self.running().filter(|r| r.generation == generation)
    }

+    /// Instance `generation` is starting or running: not stopped, crashed or replaced.
+    /// Work it reports before it is ready (a Gradle import answers `initialize` late) still counts.
+    pub fn is_live(&self, generation: u64) -> bool {
+        let st = self.state.lock();
+        st.generation == generation && matches!(st.conn, Conn::Starting | Conn::Ready(_))
+    }
+
    /// Waits through startup or a planned restart; returns the instance once ready.
    pub async fn wait_ready(&self, timeout: Duration) -> Option<Running> {
        let mut rx = self.phase.subscribe();
@@ -436,10 +466,12 @@ impl Server {
        }
        let tail = self.stderr_tail(5);
        let cfg = self.effective_config();
-        let mut message = match (code, &cfg.connect) {
-            (Some(c), _) => format!("{} exited with code {c}", self.name),
-            (None, Some(addr)) => format!("{}: the connection to the server ({addr}) closed", self.name),
-            (None, None) => format!("{} terminated unexpectedly", self.name),
+        let start_error = self.start_error.lock().take().filter(|(g, _)| *g == generation).map(|(_, r)| r);
+        let mut message = match (&start_error, code, &cfg.connect) {
+            (Some(reason), _, _) => format!("{} failed to start: {reason}", self.name),
+            (None, Some(c), _) => format!("{} exited with code {c}", self.name),
+            (None, None, Some(addr)) => format!("{}: the connection to the server ({addr}) closed", self.name),
+            (None, None, None) => format!("{} terminated unexpectedly", self.name),
        };
        if !tail.is_empty() {
            message.push_str(":\n");
@@ -472,6 +504,7 @@ impl Server {
    /// Records a crash; returns the backoff before restarting, or `None` once
    /// [`MAX_RESTARTS`] instances in a row died before running [`STABLE_UPTIME`]
    /// (a server that crashes on every start, however slowly, is not restarted forever).
+    /// An instance that never became ready has run for no time at all.
    pub fn record_crash(&self) -> Option<Duration> {
        let uptime = self.started.lock().map(|t| t.elapsed()).unwrap_or_default();
        let mut crashes = self.crashes.lock();
@@ -507,7 +540,13 @@ impl Server {
            return;
        }
        *cur = (status, message.clone());
-        st.events.push_back(IdeEvent::LanguageServer { server: self.id, name: self.name.clone(), status, message });
+        st.events.push_back(IdeEvent::LanguageServer {
+            server: self.id,
+            name: self.name.clone(),
+            label: self.display_name(),
+            status,
+            message,
+        });
    }

    fn queue_cleanup(&self, st: &mut State) {
@@ -1028,6 +1067,38 @@ mod tests {
        assert!(s.is_busy(), "a reporting task keeps the server busy");
    }

+    #[test]
+    fn only_time_spent_ready_counts_as_uptime() {
+        let sink: SharedSink = Arc::new(|_: IdeEvent| {});
+        let s = server();
+        for n in 1..=MAX_RESTARTS + 1 {
+            // Never ready: crashes after a slow start count however long the start took.
+            let generation = s.begin_start().unwrap();
+            assert!(s.started.lock().is_none());
+            s.set_start_error(generation, "it did not answer initialize within 300 s".into());
+            let delay = s.on_closed(generation, &sink, None).unwrap();
+            assert_eq!(delay.is_some(), n <= MAX_RESTARTS, "crash {n}");
+            let message = s.status_message().unwrap();
+            assert!(
+                message.starts_with(&format!("{} failed to start: it did not answer initialize", s.name)),
+                "{message}"
+            );
+            s.state.lock().conn = Conn::Idle;
+        }
+        assert!(matches!(s.state.lock().conn, Conn::Idle));
+    }
+
+    #[test]
+    fn an_instance_is_live_from_its_start_until_it_is_retired() {
+        let sink: SharedSink = Arc::new(|_: IdeEvent| {});
+        let s = server();
+        let generation = s.begin_start().unwrap();
+        assert!(s.is_live(generation), "still starting: its progress (an import) is being watched");
+        assert!(!s.is_live(generation + 1));
+        assert!(s.fail_start(generation, Conn::Failed, &sink, ServerStatus::Crashed, None));
+        assert!(!s.is_live(generation));
+    }
+
    #[test]
    fn crashes_of_short_lived_instances_exhaust_the_budget_whatever_the_spacing() {
        let s = server();
@@ -341,6 +341,10 @@ pub struct ServerInfo {
    pub status: ServerStatus,
    /// OS process of the running instance (for memory attribution).
    pub pid: Option<u32>,
+    /// What the user sees as the server when another program serves in its place.
+    #[serde(default)]
+    #[specta(optional)]
+    pub label: Option<String>,
 }

 /// Read-only contents a language server provides for a non-`file:` URI