fix(project-view): paste a clipboard image as img.png

Pasting into the Project view only handled files, so a screenshot on the
clipboard did nothing. With no files to paste, Paste now saves the clipboard
image in the target folder as img.png (img_1.png, img_2.png ... when taken)
and selects it; Paste is enabled while the clipboard holds an image.

The image is read natively: public.png, or public.tiff converted, on macOS;
the registered PNG format, or CF_DIB (24/32-bit) encoded as PNG, on Windows;
GTK on Linux as before.

Fixes #3486

Cargo.lock

@@ -4232,6 +4232,7 @@ dependencies = [
  "objc2 0.6.5",
  "objc2-app-kit 0.3.2",
  "objc2-foundation 0.3.2",
+ "png 0.18.1",
 ]
 
 [[package]]
@@ -4269,6 +4270,7 @@ dependencies = [
 name = "ide-dap"
 version = "0.1.45"
 dependencies = [
+ "base64 0.22.1",
  "futures",
  "ide-core",
  "ide-heap",
@@ -4287,6 +4289,7 @@ dependencies = [
  "specta",
  "tempfile",
  "tokio",
+ "tokio-tungstenite",
  "tracing",
  "tracing-subscriber",
  "windows-sys 0.61.2",

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

@@ -17,11 +17,30 @@ const DISCOVER_TIMEOUT: Duration = if cfg!(test) { Duration::from_secs(3) } else
 
 /// Opens `session/new`, reads `configOptions`, and records per-model `thought_level` choices.
 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())?;

crates/ide-agent/src/lib.rs

@@ -283,6 +283,11 @@ struct TaskFile {
     /// The folder (in the task store) with copies of the `before` files, for rolling back.
     #[serde(default, skip_serializing_if = "Option::is_none")]
     saved: Option<String>,
+    /// In the project's own checkout, where the user and other tasks change files too: the
+    /// files that changed while one of this task's turns ran, the only ones its changes list.
+    /// `None` for a worktree task, and a task saved before these were recorded.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    touched: Option<BTreeSet<String>>,
     #[serde(default, skip_serializing_if = "Vec::is_empty")]
     subagents: Vec<SavedSubagent>,
     /// Turns to drop from the session once it is loaded (a fork of an earlier point).
@@ -293,6 +298,9 @@ struct TaskFile {
     title_renamed: bool,
 }
 
+/// The changed files of a checkout, stamped.
+type Snapshot = BTreeMap<String, worktree::Stamp>;
+
 struct TaskState {
     task: AgentTask,
     session_id: Option<String>,
@@ -300,11 +308,18 @@ struct TaskState {
     wanted: Vec<AgentConfigChoice>,
     before: Arc<BTreeMap<String, worktree::Stamp>>,
     saved: Option<String>,
+    /// See `TaskFile::touched`.
+    touched: Option<Arc<BTreeSet<String>>>,
     pending_rollback: u32,
     /// The user named the task; see `TaskFile::title_renamed`.
     title_renamed: bool,
     /// A turn is running or about to (prompts arriving now are queued).
     busy: bool,
+    /// A temporary side conversation: lives in memory only, never persisted.
+    ephemeral: bool,
+    /// The conversation a temporary side conversation starts with, sent to the agent with
+    /// its first real message; the task's own entries hold only the questions.
+    ephemeral_context: Option<String>,
     /// Background tasks the agent reported as running (`run_in_background` commands and
     /// the like), as it sent them: unlike a turn they outlive it, so an idle release
     /// waits for the last one. A (re)started process runs nothing yet.
@@ -424,8 +439,14 @@ impl AgentManager {
     }
 
     /// Routes events to `sink` (replacing the previous subscriber); returns every task.
+    /// Ephemeral tasks belonged to the previous page session: a fresh one starts without them.
     pub fn subscribe(&self, sink: AgentSink) -> Vec<AgentTask> {
         *self.shared.sink.write() = Some(sink);
+        let stale: Vec<Arc<Task>> = self.tasks.read().values().filter(|t| t.state.lock().ephemeral).cloned().collect();
+        for task in &stale {
+            self.drop_in_memory(task);
+            self.shared.emit(AgentEvent::Removed { id: task.id.clone() });
+        }
         let mut tasks: Vec<AgentTask> = self.tasks.read().values().map(|t| t.state.lock().task.clone()).collect();
         tasks.sort_by(|a, b| b.updated_ms.total_cmp(&a.updated_ms));
         tasks
@@ -655,19 +676,18 @@ impl AgentManager {
             retry: None,
             background: Box::default(),
         };
-        let file = TaskFile {
+        let handle = self.register(TaskFile {
             task: task.clone(),
             session_id: Some(session_id.to_owned()),
             entries: Vec::new(),
             wanted: Vec::new(),
             before: BTreeMap::new(),
             saved: None,
+            touched: Some(BTreeSet::new()),
             subagents: Vec::new(),
             pending_rollback: 0,
             title_renamed: true,
-        };
-        let handle = Task::restore(file, self.shared.clone());
-        self.tasks.write().insert(task.id.clone(), handle.clone());
+        });
         handle.emit_task();
         handle.persist();
         Ok(task)
@@ -705,27 +725,8 @@ impl AgentManager {
                 (root, None, base, commit, before)
             }
         };
-        // Until the session reports its own, show what the agent offered last time with the choices applied.
-        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) = levels.remove(&model)
-        {
-            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))
-                {
-                    o.current = Some(choice.value.clone());
-                }
-                o
-            }));
-        }
+        // The session's settings: what the agent offered last time, with the choices applied.
+        let config = self.merged_config(&spec.id, &req.config);
         let now = now_ms();
         let id = uuid::Uuid::new_v4().simple().to_string();
         // Copies of the files the user had changed already, for rolling back the task's changes to them.
@@ -766,26 +767,128 @@ impl AgentManager {
             retry: None,
             background: Box::default(),
         };
-        let file = TaskFile {
+        let handle = self.register(TaskFile {
             task: task.clone(),
             session_id: None,
             entries: Vec::new(),
             wanted: req.config,
             before,
             saved,
+            touched: (req.isolation == Isolation::Local).then(BTreeSet::new),
             subagents: Vec::new(),
             pending_rollback: 0,
             title_renamed: false,
-        };
-        let handle = Task::restore(file, self.shared.clone());
+        });
         handle.state.lock().busy = true;
-        self.tasks.write().insert(task.id.clone(), handle.clone());
-        handle.emit_task();
         handle.persist();
         self.shared.runtime.spawn(async move { handle.run(prompt).await });
         Ok(task)
     }
 
+    /// Builds the in-memory handle of a fresh task, registers it and announces it. The
+    /// caller decides what else its life starts with (a persisted file, a session, a run).
+    fn register(&self, file: TaskFile) -> Arc<Task> {
+        let handle = Task::restore(file, self.shared.clone());
+        self.tasks.write().insert(handle.id.clone(), handle.clone());
+        handle.emit_task();
+        handle
+    }
+
+    /// The session's settings: what the agent offered last time, with the request's
+    /// choices — and the chosen model's thought levels — applied.
+    fn merged_config(&self, provider: &str, req: &[AgentConfigChoice]) -> Vec<AgentConfigOption> {
+        let catalog = self.shared.paths.catalogs.cached(&self.shared, provider);
+        let mut levels = catalog.thought_levels;
+        let mut config = self.shared.config_for_new_task(catalog.config, provider);
+        for choice in req {
+            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) = levels.remove(&model)
+        {
+            config.extend(levels.into_iter().map(|mut o| {
+                if let Some(choice) = req.iter().find(|c| c.id == o.id && o.values.iter().any(|v| v.value == c.value)) {
+                    o.current = Some(choice.value.clone());
+                }
+                o
+            }));
+        }
+        config
+    }
+
+    /// Creates a temporary side conversation of `source`: an in-memory task that is never
+    /// persisted, whose session starts with its first real message (`prompt` only names
+    /// the title). `source`'s conversation rides along as the context of that message.
+    /// The task is read-only: its settings are pushed to a mode that asks before anything,
+    /// and requests that would change the project are denied regardless. Fails for an
+    /// agent that offers no way to ask.
+    pub async fn create_ephemeral(&self, req: NewAgentTask, source: &str) -> IdeResult<AgentTask> {
+        let spec = self
+            .shared
+            .spec(&req.provider)
+            .ok_or_else(|| IdeError::invalid(format!("unknown agent {}", req.provider)))?;
+        let prompt = clean(req.prompt).ok_or_else(|| IdeError::invalid("describe the topic first"))?;
+        let title = title_of(&prompt);
+        let mut config = self.merged_config(&spec.id, &req.config);
+        config::ask_for_approvals(&mut config);
+        if config::bypass_approvals(&config) {
+            return Err(IdeError::invalid(
+                "this agent has no mode that asks before changing things, so it can't run a side conversation",
+            ));
+        }
+        let read_only = !config::bypass_approvals(&config);
+        let context = context_transcript(&self.task(source)?.state.lock().conversation.main.entries);
+        let root = self.shared.paths.project_root.clone();
+        let before = blocking(move || Ok(worktree::snapshot(&root).unwrap_or_default())).await?;
+        let now = now_ms();
+        let mut capabilities = self.shared.probes.lock().get(&spec.id).map(|p| p.capabilities).unwrap_or_default();
+        capabilities.read_only = read_only;
+        let task = AgentTask {
+            project_root: Some(IpcPath(self.shared.paths.project_root.clone())),
+            id: uuid::Uuid::new_v4().simple().to_string(),
+            title,
+            provider: spec.id.clone(),
+            model: model_of(&config),
+            status: AgentStatus::Ready,
+            isolation: Isolation::Local,
+            cwd: IpcPath(self.shared.paths.project_root.clone()),
+            branch: None,
+            base: None,
+            base_commit: None,
+            error: None,
+            created_ms: now,
+            updated_ms: now,
+            commands: self.shared.known_commands(&spec.id),
+            usage: None,
+            queue: Vec::new(),
+            capabilities,
+            resets_ms: None,
+            retry: None,
+            background: Box::default(),
+            config,
+        };
+        let handle = self.register(TaskFile {
+            task: task.clone(),
+            session_id: None,
+            entries: Vec::new(),
+            wanted: req.config,
+            before,
+            saved: None,
+            touched: None,
+            subagents: Vec::new(),
+            pending_rollback: 0,
+            title_renamed: false,
+        });
+        {
+            let mut s = handle.state.lock();
+            s.ephemeral = true;
+            s.ephemeral_context = Some(context);
+        }
+        Ok(task)
+    }
+
     /// Sends a message. While the agent works it is queued, or with `now` the current turn
     /// is cancelled and the message goes next.
     pub async fn prompt(&self, id: &str, prompt: AgentPrompt, now: bool) -> IdeResult<()> {
@@ -1006,6 +1109,7 @@ impl AgentManager {
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
                 saved: s.saved.clone(),
+                touched: s.touched.as_deref().cloned(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: total - keep,
                 title_renamed: s.title_renamed,
@@ -1205,6 +1309,15 @@ impl AgentManager {
         Ok(())
     }
 
+    /// Removes a task from the manager's table and stops its agent. The disk (its file,
+    /// its worktree) is the caller's business.
+    fn drop_in_memory(&self, task: &Arc<Task>) {
+        task.kill();
+        self.tasks.write().remove(&task.id);
+        *task.deleted.lock() = true;
+        let _ = std::fs::remove_file(self.shared.paths.store_dir.join(format!("{}.json", task.id)));
+    }
+
     /// Returns an archived task to the active list without starting the agent.
     pub fn unarchive(&self, id: &str) -> IdeResult<()> {
         let task = self.task(id)?;
@@ -1288,8 +1401,8 @@ impl AgentManager {
     pub async fn changes(&self, id: &str) -> IdeResult<Vec<AgentChange>> {
         let task = self.task(id)?;
         let at = task.base();
-        let before = task.state.lock().before.clone();
-        blocking(move || at.changes(&before)).await
+        let (before, touched) = task.attribution();
+        blocking(move || Ok(worktree::made_by_task(at.changes(&before)?, touched.as_deref()))).await
     }
 
     /// The task's uncommitted changes and, for a worktree task, the commits made since it
@@ -1297,8 +1410,13 @@ impl AgentManager {
     pub async fn grouped_changes(&self, id: &str) -> IdeResult<AgentChanges> {
         let task = self.task(id)?;
         let at = task.base();
-        let before = task.state.lock().before.clone();
-        blocking(move || at.grouped_changes(&before)).await
+        let (before, touched) = task.attribution();
+        blocking(move || {
+            let mut grouped = at.grouped_changes(&before)?;
+            grouped.uncommitted = worktree::made_by_task(grouped.uncommitted, touched.as_deref());
+            Ok(grouped)
+        })
+        .await
     }
 
     /// Content of `path` (in the task's directory) when the task started.
@@ -1324,15 +1442,16 @@ impl AgentManager {
             return Err(IdeError::invalid("the agent is working: stop it before rolling back its changes"));
         }
         let at = task.base();
-        let (before, saved) = {
+        let (before, saved, touched) = {
             let s = task.state.lock();
-            (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)))
+            (s.before.clone(), s.saved.as_ref().map(|name| self.shared.paths.store_dir.join(name)), s.touched.clone())
         };
         let restamped = blocking(move || {
             let (changes, rev) = match view {
                 AgentChangesView::Group => (at.grouped_changes(&before)?.uncommitted, worktree::head_commit(at.cwd())?),
                 AgentChangesView::SinceStart => (at.changes(&before)?, at.rev()?),
             };
+            let changes = worktree::made_by_task(changes, touched.as_deref());
             let sources = match rev.as_deref() {
                 Some(rev) => worktree::rename_sources(at.cwd(), rev)?,
                 None => Default::default(),
@@ -1423,9 +1542,12 @@ impl Task {
                 wanted: file.wanted,
                 before: Arc::new(file.before),
                 saved: file.saved,
+                touched: file.touched.map(Arc::new),
                 pending_rollback: file.pending_rollback,
                 title_renamed: file.title_renamed,
                 busy: false,
+                ephemeral: false,
+                ephemeral_context: None,
                 background_tasks: Vec::new(),
             }),
             live: Mutex::new(None),
@@ -1447,6 +1569,41 @@ impl Task {
         })
     }
 
+    /// The files already changed when the task started, and the files its turns changed.
+    fn attribution(&self) -> (Arc<Snapshot>, Option<Arc<BTreeSet<String>>>) {
+        let s = self.state.lock();
+        (s.before.clone(), s.touched.clone())
+    }
+
+    /// The changed files of the checkout as a turn starts, when the task records what its turns change.
+    async fn checkout_before_turn(&self) -> Option<Snapshot> {
+        let cwd = {
+            let s = self.state.lock();
+            s.touched.as_ref()?;
+            s.task.cwd.0.clone()
+        };
+        blocking(move || worktree::snapshot(&cwd)).await.ok()
+    }
+
+    /// Records the files that changed in the checkout since `start`, as the turn ends, as the task's.
+    async fn record_turn_changes(&self, start: Option<Snapshot>) {
+        let Some(start) = start else { return };
+        let cwd = self.state.lock().task.cwd.0.clone();
+        let Ok(end) = blocking(move || worktree::snapshot(&cwd)).await else { return };
+        let changed = worktree::changed_between(&start, &end);
+        if changed.is_empty() {
+            return;
+        }
+        {
+            let mut s = self.state.lock();
+            let Some(touched) = &s.touched else { return };
+            let mut touched = (**touched).clone();
+            touched.extend(changed);
+            s.touched = Some(Arc::new(touched));
+        }
+        self.persist();
+    }
+
     fn base(&self) -> worktree::TaskBase {
         let s = self.state.lock();
         let cwd = s.task.cwd.0.clone();
@@ -1527,6 +1684,9 @@ impl Task {
         if *deleted {
             return;
         }
+        if self.state.lock().ephemeral {
+            return;
+        }
         let bytes = {
             let s = self.state.lock();
             serde_json::to_vec(&TaskFile {
@@ -1536,6 +1696,7 @@ impl Task {
                 wanted: s.wanted.clone(),
                 before: (*s.before).clone(),
                 saved: s.saved.clone(),
+                touched: s.touched.as_deref().cloned(),
                 subagents: s.conversation.saved_subagents(),
                 pending_rollback: s.pending_rollback,
                 title_renamed: s.title_renamed,
@@ -1587,9 +1748,11 @@ impl Task {
     /// the user stops one. The caller set `busy`.
     async fn run(self: Arc<Self>, mut prompt: AgentPrompt) {
         loop {
+            let start = self.checkout_before_turn().await;
             let result = self.turn(&prompt).await;
             self.cancel_pending.store(false, Ordering::Release);
             tokio::time::sleep(TURN_GRACE).await;
+            self.record_turn_changes(start).await;
             let changed = self.state.lock().conversation.end_turn(Some(now_ms()));
             self.mark_dirty(changed);
             let send_now = self.send_now.swap(false, Ordering::AcqRel);
@@ -1757,7 +1920,20 @@ impl Task {
         if !prompt.images.is_empty() && !live.capabilities.images {
             return Err(Failure::from("This agent can't read images.".to_owned()));
         }
-        let content = self.content(&live, prompt).await;
+        // A temporary side conversation's context rides with its first real message; the
+        // conversation itself records only the question (and whatever comes after).
+        let prompt = {
+            let context = self.state.lock().ephemeral_context.take();
+            match context {
+                Some(context) => {
+                    let mut owned = prompt.clone();
+                    owned.text = format!("{context}\n\n---\n\n{}", owned.text);
+                    owned
+                }
+                None => prompt.clone(),
+            }
+        };
+        let content = self.content(&live, &prompt).await;
         let result: Result<Value, RpcError> =
             live.peer.request("session/prompt", json!({ "sessionId": live.session, "prompt": content }), None).await;
         match result {
@@ -2211,6 +2387,29 @@ impl Task {
                     .collect()
             })
             .unwrap_or_default();
+        // A side conversation is read-only: deny anything that would change the project
+        // (its task is deleted when its pane closes, leaving nothing to review or revert).
+        if self.state.lock().ephemeral
+            && params
+                .pointer("/toolCall/kind")
+                .or_else(|| params.pointer("/subject/toolCall/kind"))
+                .and_then(Value::as_str)
+                .is_some_and(|kind| matches!(kind, "edit" | "delete" | "move" | "execute"))
+        {
+            let reject = options.iter().find(|o| o.kind.starts_with("reject")).cloned();
+            let _ = self.push_entry(AgentEntry::Permission {
+                id,
+                title,
+                command: None,
+                options,
+                questions: Vec::new(),
+                chosen: Some("Denied: side conversations are read-only".to_owned()),
+            });
+            return match reject {
+                Some(option) => json!({ "outcome": { "outcome": "selected", "optionId": option.id } }),
+                None => json!({ "outcome": { "outcome": "cancelled" } }),
+            };
+        }
         let asked: Vec<String> = questions
             .iter()
             .map(|question| question.answer_key.clone().unwrap_or_else(|| question.question.clone()))
@@ -2408,6 +2607,72 @@ fn clean(mut prompt: AgentPrompt) -> Option<AgentPrompt> {
     (!prompt.text.is_empty() || !prompt.images.is_empty() || !prompt.files.is_empty()).then_some(prompt)
 }
 
+/// The character budget of a side conversation's context: the newest entries win, the
+/// oldest are dropped first. Leaves room for the question and the agent's answer.
+const CONTEXT_BUDGET: usize = 100_000;
+
+/// A long tool output trimmed to its first and last few lines, with the elided middle noted.
+fn trimmed_output(output: &str) -> String {
+    const KEPT: usize = 4;
+    let lines: Vec<&str> = output.lines().collect();
+    if lines.len() <= KEPT * 2 + 1 {
+        return output.to_owned();
+    }
+    let omitted = lines.len() - KEPT * 2;
+    let mut out = lines[..KEPT].join("\n");
+    out.push_str(&format!("\n… {omitted} lines omitted …\n"));
+    out.push_str(&lines[lines.len() - KEPT..].join("\n"));
+    out
+}
+
+fn context_entry(e: &AgentEntry) -> Option<String> {
+    match e {
+        AgentEntry::User { text, .. } => Some(format!("User: {text}")),
+        AgentEntry::Agent { text, .. } if !text.trim().is_empty() => Some(format!("Agent: {text}")),
+        AgentEntry::Thought { text, .. } if !text.trim().is_empty() => Some(format!("Thought: {text}")),
+        AgentEntry::Tool { title, output, .. } => match output.as_deref() {
+            Some(output) if !output.trim().is_empty() => Some(format!("Tool: {title}\n{}", trimmed_output(output))),
+            _ => Some(format!("Tool: {title}")),
+        },
+        AgentEntry::Error { message, .. } => Some(format!("Error: {message}")),
+        _ => None,
+    }
+}
+
+/// The conversation as the context a temporary side conversation starts with: what was
+/// said, what was done (tool calls with trimmed output), errors and the agent's reasoning,
+/// oldest first, within [`CONTEXT_BUDGET`].
+fn context_transcript(entries: &[AgentEntry]) -> String {
+    // Newest wins: walk back until the budget is spent, dropping the oldest entries first.
+    let mut lines: Vec<String> = Vec::new();
+    let mut used = 0usize;
+    for e in entries.iter().rev() {
+        let Some(line) = context_entry(e) else { continue };
+        if used + line.len() > CONTEXT_BUDGET {
+            if lines.is_empty() {
+                // Even the newest entry alone exceeds the budget: keep its head.
+                lines.push(line.chars().take(CONTEXT_BUDGET).collect());
+            }
+            break;
+        }
+        used += line.len();
+        lines.push(line);
+    }
+    lines.reverse();
+    let dropped = entries.iter().rev().filter_map(context_entry).count() - lines.len();
+    let mut context = String::from(
+        "You are answering a side question in a temporary conversation. The conversation so far is below, \
+         for context only; answer the new question after the marker, and do not continue the main task \
+         unless asked.\n\n<conversation>\n",
+    );
+    if dropped > 0 {
+        context.push_str(&format!("(The {dropped} oldest entries are omitted.)\n\n"));
+    }
+    context.push_str(&lines.join("\n\n"));
+    context.push_str("\n</conversation>");
+    context
+}
+
 fn permission_title(params: &Value) -> String {
     let call = &params["toolCall"];
     let title = call.get("title").and_then(Value::as_str).filter(|t| !t.is_empty());
@@ -2608,6 +2873,7 @@ fn capabilities_of(init: &acp::Negotiated) -> (AgentCapabilities, bool) {
         rollback: meta("/openidea/rollback"),
         steer: meta("/openidea/steer"),
         background_tasks: meta("/openidea/backgroundTasks"),
+        read_only: false,
     };
     (capabilities, init.prompt("embeddedContext"))
 }

crates/ide-agent/src/model.rs

@@ -36,6 +36,9 @@ pub struct AgentCapabilities {
     pub steer: bool,
     /// It reports its background tasks and stops them one by one.
     pub background_tasks: bool,
+    /// The task runs read-only: it asks before anything, and requests that would change
+    /// the project are denied (a temporary side conversation).
+    pub read_only: bool,
 }
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]

crates/ide-agent/src/provider.rs

@@ -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())]
+        );
+    }
 }

crates/ide-agent/src/tests.rs

@@ -2211,6 +2211,7 @@ async fn task_project_root_controls_local_and_worktree_repositories() {
             .unwrap();
         mgr.respond(&task.id, permission, Some("yes".into())).unwrap();
         wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+        count_every_change(&mgr, &task.id);
         assert_eq!(task.project_root, Some(IpcPath(member.clone())));
         assert_eq!(task.base.as_deref(), Some("member-main"));
         if isolation == Isolation::Local {
@@ -2842,12 +2843,14 @@ async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edi
         .await
         .unwrap();
     wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
-    mgr.cancel(&task.id, None).unwrap();
-    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
-    // What the agent did.
+    // What the agent did, while its turn ran.
     write("mine.txt", "my edit\nand the agent's\n");
     write("other.txt", "agent\n");
     write("new.txt", "agent\n");
+    mgr.cancel(&task.id, None).unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    // The user's (or another task's) work between turns is not the task's.
+    write("later.txt", "mine\n");
     async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
         mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
     }
@@ -2863,6 +2866,7 @@ async fn rolling_back_restores_the_start_of_the_task_and_keeps_the_users_own_edi
     mgr.rollback_changes(&task.id, None, AgentChangesView::SinceStart).await.unwrap();
     assert_eq!(read("mine.txt"), "my edit\n", "the user's edit stays");
     assert!(!dir.join("new.txt").exists());
+    assert_eq!(read("later.txt"), "mine\n", "not the task's to roll back");
     assert!(changed(&mgr, &task.id).await.is_empty());
 
     mgr.delete(&task.id, false).await.unwrap();
@@ -2947,10 +2951,17 @@ impl Checkout {
         wait_for(&mgr, &task.id, AgentStatus::NeedsInput).await;
         mgr.cancel(&task.id, None).unwrap();
         wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+        count_every_change(&mgr, &task.id);
         (mgr, task)
     }
 }
 
+/// Counts every change in the checkout as the task's, as for a task saved before tasks
+/// recorded what their turns changed: for tests that change files outside a turn.
+fn count_every_change(mgr: &AgentManager, id: &str) {
+    mgr.task(id).unwrap().state.lock().touched = None;
+}
+
 async fn changed(mgr: &AgentManager, id: &str) -> Vec<String> {
     mgr.changes(id).await.unwrap().into_iter().map(|c| c.rel_path).collect()
 }
@@ -3227,3 +3238,192 @@ async fn security_policy_never_auto_approves_a_request_that_only_reads_like_a_co
         "{entries:?}"
     );
 }
+
+/// A temporary side conversation is created ready, without starting its session and
+/// without writing anything to the store; a fresh subscriber (a reloaded page) sweeps
+/// it, and deleting it just drops it from memory.
+#[tokio::test(flavor = "multi_thread")]
+async fn ephemeral_tasks_stay_in_memory_only() {
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    let source = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("hello"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::NeedsInput).await;
+    let calls_before = agent.calls.lock().len();
+    let task = mgr
+        .create_ephemeral(
+            NewAgentTask {
+                project_root: None,
+                prompt: text("What changed in this file?"),
+                provider: "claude".into(),
+                config: vec![],
+                isolation: Isolation::Local,
+                base: None,
+            },
+            &source.id,
+        )
+        .await
+        .unwrap();
+    // Registering it starts nothing: the session waits for its first real message.
+    assert_eq!(agent.calls.lock().len(), calls_before);
+    assert_eq!(mgr.task(&task.id).unwrap().state.lock().task.status, AgentStatus::Ready);
+    assert!(!tmp.path().join("store").join(format!("{}.json", task.id)).exists());
+
+    // Its first message starts the session like any task's, and still saves nothing: the
+    // conversation records the question, not the context that rode along to the agent.
+    // The fake agent's turn asks to change something, which a side conversation denies by
+    // itself, so the turn ends without waiting for the user.
+    mgr.prompt(&task.id, text("Why?"), false).await.unwrap();
+    wait_for(&mgr, &task.id, AgentStatus::Ready).await;
+    let entries = mgr.entries(&task.id, None).unwrap();
+    let question = entries.iter().find_map(|e| match e {
+        AgentEntry::User { text, .. } => Some(text.clone()),
+        _ => None,
+    });
+    assert_eq!(question.as_deref(), Some("Why?"));
+    assert!(
+        entries.iter().any(|e| matches!(e, AgentEntry::Permission { chosen: Some(c), .. } if c.contains("read-only"))),
+        "its `cargo test` request was denied: {entries:?}"
+    );
+    assert!(!tmp.path().join("store").join(format!("{}.json", task.id)).exists());
+
+    // A fresh subscriber (a reloaded page) sweeps it: it never reaches the task list.
+    let events: Arc<Mutex<Vec<AgentEvent>>> = Arc::new(Mutex::new(Vec::new()));
+    let sink_events = events.clone();
+    let tasks = mgr.subscribe(Arc::new(move |e| sink_events.lock().push(e)));
+    assert!(!tasks.iter().any(|t| t.id == task.id));
+    assert!(mgr.task(&task.id).is_err());
+    assert!(events.lock().iter().any(|e| matches!(e, AgentEvent::Removed { id } if *id == task.id)));
+    mgr.shutdown();
+}
+
+/// A side conversation's context stays within its budget: long tool outputs are cut to
+/// their head and tail, and entries that no longer fit are dropped oldest first.
+#[test]
+fn side_conversation_context_is_bounded() {
+    let long_output = (0..400).map(|i| format!("line {i}")).collect::<Vec<_>>().join(
+        "
+",
+    );
+    // Each reply alone is well inside the budget; together they are past it.
+    let reply = |n: usize| AgentEntry::Agent { text: format!("reply {n} {}", "x".repeat(30_000)) };
+    let entries = vec![
+        AgentEntry::User {
+            text: "oldest question".into(),
+            attachments: vec![],
+            images: vec![],
+            sent_ms: None,
+            done_ms: None,
+            steered: false,
+        },
+        reply(1),
+        reply(2),
+        reply(3),
+        reply(4),
+        AgentEntry::Tool {
+            id: "t1".into(),
+            title: "grep".into(),
+            kind: "search".into(),
+            status: AgentToolStatus::Completed,
+            locations: vec![],
+            output: Some(long_output),
+            diffs: vec![],
+        },
+        AgentEntry::User {
+            text: "newest question".into(),
+            attachments: vec![],
+            images: vec![],
+            sent_ms: None,
+            done_ms: None,
+            steered: false,
+        },
+    ];
+    let transcript = context_transcript(&entries);
+    assert!(transcript.contains("newest question"), "the newest entry is always kept");
+    assert!(transcript.contains("lines omitted"), "a long tool output is trimmed");
+    assert!(transcript.contains("line 0") && transcript.contains("line 399"), "its head and tail stay");
+    assert!(!transcript.contains("oldest question"), "entries past the budget are dropped oldest first");
+    assert!(transcript.contains("oldest entries are omitted"));
+}
+
+/// An ephemeral task denies a permission request that would change the project.
+#[tokio::test(flavor = "multi_thread")]
+async fn ephemeral_tasks_deny_write_permissions() {
+    let tmp = tempfile::tempdir().unwrap();
+    let agent = Arc::new(FakeAgent::default());
+    let mgr = manager(tmp.path(), agent.clone());
+    let source = mgr
+        .create(NewAgentTask {
+            project_root: None,
+            prompt: text("Something with a conversation to reuse"),
+            provider: "claude".into(),
+            config: vec![],
+            isolation: Isolation::Local,
+            base: None,
+        })
+        .await
+        .unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::NeedsInput).await;
+    let pending = mgr
+        .entries(&source.id, None)
+        .unwrap()
+        .iter()
+        .find_map(|e| match e {
+            AgentEntry::Permission { id, chosen: None, .. } => Some(*id),
+            _ => None,
+        })
+        .unwrap_or_else(|| panic!("no pending permission request"));
+    mgr.respond(&source.id, pending, Some("no".into())).unwrap();
+    wait_for(&mgr, &source.id, AgentStatus::Ready).await;
+
+    let task = mgr
+        .create_ephemeral(
+            NewAgentTask {
+                project_root: None,
+                prompt: text("What changed in this file?"),
+                provider: "claude".into(),
+                config: vec![],
+                isolation: Isolation::Local,
+                base: None,
+            },
+            &source.id,
+        )
+        .await
+        .unwrap();
+    assert!(mgr.task(&task.id).unwrap().state.lock().task.capabilities.read_only);
+
+    let answer = mgr
+        .task(&task.id)
+        .unwrap()
+        .ask_permission(&json!({
+            "sessionId": "c1",
+            "toolCall": {"toolCallId": "c1-t2", "title": "Edit main.rs", "kind": "edit"},
+            "options": [
+                {"optionId": "yes", "name": "Allow", "kind": "allow_once"},
+                {"optionId": "no", "name": "Reject", "kind": "reject_once"}
+            ]
+        }))
+        .pointer("/outcome/optionId")
+        .and_then(Value::as_str)
+        .unwrap_or("none")
+        .to_owned();
+    assert_eq!(answer, "no", "the write request is denied");
+    let entries = mgr.entries(&task.id, None).unwrap();
+    assert!(
+        entries
+            .iter()
+            .any(|e| matches!(e, AgentEntry::Permission { chosen: Some(chosen), .. } if chosen.contains("read-only"))),
+        "{entries:?}"
+    );
+    mgr.shutdown();
+}

crates/ide-agent/src/worktree.rs

@@ -3,7 +3,7 @@
 use crate::model::{AgentChange, AgentChanges, AgentCommit};
 use ide_core::{IdeError, IdeResult, IpcPath};
 use ide_vcs::{ChangeKind, LogQuery, Repo};
-use std::collections::BTreeMap;
+use std::collections::{BTreeMap, BTreeSet};
 use std::path::{Path, PathBuf};
 use std::time::{Duration, UNIX_EPOCH};
 
@@ -548,6 +548,25 @@ pub(crate) fn snapshot(cwd: &Path) -> IdeResult<BTreeMap<String, Stamp>> {
     Ok(repo.status()?.into_iter().map(|s| (s.rel_path, stamp(&s.path))).collect())
 }
 
+/// The files whose state changed between two snapshots of a checkout: edited, new, deleted,
+/// or back to as committed.
+pub(crate) fn changed_between(start: &BTreeMap<String, Stamp>, end: &BTreeMap<String, Stamp>) -> Vec<String> {
+    let mut changed: Vec<String> =
+        end.iter().filter(|(path, stamp)| start.get(*path) != Some(*stamp)).map(|(path, _)| path.clone()).collect();
+    changed.extend(start.keys().filter(|path| !end.contains_key(*path)).cloned());
+    changed
+}
+
+/// The changes among `changes` that the task made, when it records the files its turns
+/// changed (`None`: every change counts).
+pub(crate) fn made_by_task(changes: Vec<AgentChange>, touched: Option<&BTreeSet<String>>) -> Vec<AgentChange> {
+    let Some(touched) = touched else { return changes };
+    changes
+        .into_iter()
+        .filter(|c| touched.contains(&c.rel_path) || c.old_path.as_ref().is_some_and(|old| touched.contains(old)))
+        .collect()
+}
+
 /// Drops the changes that were there before the task and haven't been touched since.
 pub(crate) fn without_untouched(changes: Vec<AgentChange>, before: &BTreeMap<String, Stamp>) -> Vec<AgentChange> {
     changes.into_iter().filter(|c| before.get(&c.rel_path).is_none_or(|s| *s != stamp(&c.path))).collect()
@@ -1184,4 +1203,20 @@ mod tests {
         assert_eq!(std::fs::read_to_string(repo.join("a.txt")).unwrap(), "one\nMINE\n");
         assert_eq!(std::fs::read_to_string(repo.join("gone.txt")).unwrap(), "bye\nbye\n");
     }
+
+    #[test]
+    fn a_turn_changed_the_files_whose_state_moved() {
+        let start: BTreeMap<String, Stamp> =
+            [("edited", Some((1, 1))), ("same", Some((2, 2))), ("reverted", Some((3, 3)))]
+                .into_iter()
+                .map(|(p, s)| (p.to_owned(), s))
+                .collect();
+        let end: BTreeMap<String, Stamp> = [("edited", Some((1, 9))), ("same", Some((2, 2))), ("new", Some((4, 4)))]
+            .into_iter()
+            .map(|(p, s)| (p.to_owned(), s))
+            .collect();
+        let mut changed = changed_between(&start, &end);
+        changed.sort();
+        assert_eq!(changed, ["edited", "new", "reverted"]);
+    }
 }

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

@@ -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<_>>();

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

@@ -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.
@@ -268,6 +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)?;
@@ -404,6 +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 {
@@ -551,6 +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(

crates/ide-clipboard/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ide-clipboard"
-description = "The OS clipboard's file list (Explorer <-> project view): Windows CF_HDROP or macOS NSPasteboard file URLs, no window or message loop"
+description = "The OS clipboard's file list (Explorer <-> project view) and pasted images: Windows CF_HDROP / PNG / CF_DIB or macOS NSPasteboard, no window or message loop"
 version.workspace = true
 edition.workspace = true
 license.workspace = true
@@ -9,8 +9,14 @@ license.workspace = true
 
 [target.'cfg(target_os = "macos")'.dependencies]
 objc2 = { version = "0.6", default-features = false, features = ["std"] }
-objc2-foundation = { version = "0.3", default-features = false, features = ["std", "NSArray", "NSDictionary", "NSEnumerator", "NSObject", "NSString", "NSURL", "NSValue"] }
-objc2-app-kit = { version = "0.3", default-features = false, features = ["std", "NSPasteboard"] }
+objc2-foundation = { version = "0.3", default-features = false, features = ["std", "NSArray", "NSData", "NSDictionary", "NSEnumerator", "NSObject", "NSString", "NSURL", "NSValue"] }
+objc2-app-kit = { version = "0.3", default-features = false, features = ["std", "NSBitmapImageRep", "NSImageRep", "NSPasteboard"] }
+
+[target.'cfg(windows)'.dependencies]
+png = "0.18"
 
 [target.'cfg(target_os = "linux")'.dependencies]
 gtk = "0.18"
+
+[dev-dependencies]
+png = "0.18"

crates/ide-clipboard/src/lib.rs

@@ -18,6 +18,10 @@
 //!
 //! Other platforms (`text/uri-list` on X11) are not wired up: [`files`] is
 //! empty and [`set_files`] fails there.
+//!
+//! [`png`] reads an image (a screenshot) for the project view's Paste, which
+//! saves it as a file: `public.png` or `public.tiff` on macOS, the registered
+//! `PNG` format or `CF_DIB` on Windows. Linux reads it through GTK in the app.
 
 use std::path::PathBuf;
 
@@ -34,6 +38,19 @@ pub fn text() -> Option<String> {
     imp::text()
 }
 
+/// The clipboard's image as PNG bytes, None when it holds none. Call on the main
+/// thread on macOS.
+#[cfg(any(windows, target_os = "macos"))]
+pub fn png() -> Option<Vec<u8>> {
+    imp::png()
+}
+
+/// Whether the clipboard holds an image, without reading it. Call on the main
+/// thread on macOS and Linux.
+pub fn has_image() -> bool {
+    imp::has_image()
+}
+
 /// Size of `DROPFILES`: `pFiles`, `pt` (two `LONG`s), `fNC`, `fWide`.
 const HEADER: usize = 20;
 
@@ -134,9 +151,62 @@ pub fn decode(bytes: &[u8]) -> Vec<PathBuf> {
     out
 }
 
+/// `BI_RGB` and `BI_BITFIELDS`: uncompressed pixels, the forms screenshots take.
+#[cfg(any(windows, test))]
+const BI_RGB: u32 = 0;
+#[cfg(any(windows, test))]
+const BI_BITFIELDS: u32 = 3;
+
+/// A packed DIB (`BITMAPINFOHEADER` or a later header, then the pixels) as PNG.
+/// Only 24- and 32-bit uncompressed bitmaps, which is what screenshots and
+/// copied images are; None for anything else. A 32-bit bitmap whose alpha is
+/// all zero (most writers leave it unset) is opaque.
+#[cfg(any(windows, test))]
+fn dib_to_png(dib: &[u8]) -> Option<Vec<u8>> {
+    let u32_at = |at: usize| dib.get(at..at + 4).map(|b| u32::from_le_bytes([b[0], b[1], b[2], b[3]]));
+    let header = u32_at(0)? as usize;
+    let width = u32_at(4)? as i32;
+    let height = u32_at(8)? as i32;
+    let bits = u16::from_le_bytes([*dib.get(14)?, *dib.get(15)?]);
+    let compression = u32_at(16)?;
+    if header < 40 || width <= 0 || height == 0 || !matches!(bits, 24 | 32) {
+        return None;
+    }
+    if compression != BI_RGB && !(compression == BI_BITFIELDS && bits == 32) {
+        return None;
+    }
+    // A `BITMAPINFOHEADER` keeps the three bitfield masks after it; later
+    // headers hold them inside. Masks other than BGRA's are not supported.
+    let masks = if compression == BI_BITFIELDS && header == 40 { 12 } else { 0 };
+    let colors = u32_at(32)? as usize;
+    let (width, rows) = (width as usize, height.unsigned_abs() as usize);
+    let stride = (width * bits as usize).div_ceil(32) * 4;
+    let start = header + masks + colors * 4;
+    let pixels = dib.get(start..start.checked_add(stride.checked_mul(rows)?)?)?;
+    let step = bits as usize / 8;
+    let mut rgba = Vec::with_capacity(width * rows * 4);
+    for row in 0..rows {
+        // A positive height stores the bottom row first.
+        let source = if height > 0 { rows - 1 - row } else { row };
+        let line = &pixels[source * stride..source * stride + width * step];
+        for px in line.chunks_exact(step) {
+            rgba.extend_from_slice(&[px[2], px[1], px[0], if step == 4 { px[3] } else { 255 }]);
+        }
+    }
+    if step == 4 && rgba.as_chunks::<4>().0.iter().all(|px| px[3] == 0) {
+        rgba.as_chunks_mut::<4>().0.iter_mut().for_each(|px| px[3] = 255);
+    }
+    let mut out = Vec::new();
+    let mut encoder = png::Encoder::new(&mut out, width as u32, rows as u32);
+    encoder.set_color(png::ColorType::Rgba);
+    encoder.set_depth(png::BitDepth::Eight);
+    encoder.write_header().ok()?.write_image_data(&rgba).ok()?;
+    Some(out)
+}
+
 #[cfg(windows)]
 mod imp {
-    use super::{HEADER, decode, encode, names_text};
+    use super::{HEADER, decode, dib_to_png, encode, names_text};
     use std::ffi::c_void;
     use std::path::PathBuf;
     use std::ptr;
@@ -164,6 +234,59 @@ mod imp {
         fn GetClipboardData(format: u32) -> Handle;
         fn SetClipboardData(format: u32, memory: Handle) -> Handle;
         fn IsClipboardFormatAvailable(format: u32) -> i32;
+        fn RegisterClipboardFormatW(name: *const u16) -> u32;
+    }
+
+    /// `CF_DIB`: Windows synthesizes it from `CF_BITMAP` and `CF_DIBV5`, so every
+    /// bitmap on the clipboard reads as one.
+    const CF_DIB: u32 = 8;
+
+    /// The `PNG` format browsers and the Snipping Tool add beside the bitmap; it
+    /// keeps transparency, so it is read first.
+    fn png_format() -> u32 {
+        let name: Vec<u16> = "PNG\0".encode_utf16().collect();
+        unsafe { RegisterClipboardFormatW(name.as_ptr()) }
+    }
+
+    pub fn has_image() -> bool {
+        let png = png_format();
+        (png != 0 && unsafe { IsClipboardFormatAvailable(png) } != 0)
+            || unsafe { IsClipboardFormatAvailable(CF_DIB) } != 0
+    }
+
+    /// A copy of the clipboard's `format` block. Call with the clipboard open.
+    fn read_block(format: u32) -> Option<Vec<u8>> {
+        // SAFETY: the clipboard keeps the block alive while it is open, and
+        // `GlobalSize` bounds the bytes read from it.
+        unsafe {
+            let memory = GetClipboardData(format);
+            if memory.is_null() {
+                return None;
+            }
+            let data = GlobalLock(memory);
+            if data.is_null() {
+                return None;
+            }
+            let bytes = std::slice::from_raw_parts(data as *const u8, GlobalSize(memory)).to_vec();
+            GlobalUnlock(memory);
+            Some(bytes)
+        }
+    }
+
+    pub fn png() -> Option<Vec<u8>> {
+        if !open() {
+            return None;
+        }
+        let png = png_format();
+        let image = if png != 0 && unsafe { IsClipboardFormatAvailable(png) } != 0 {
+            read_block(png)
+        } else if unsafe { IsClipboardFormatAvailable(CF_DIB) } != 0 {
+            read_block(CF_DIB).and_then(|dib| dib_to_png(&dib))
+        } else {
+            None
+        };
+        unsafe { CloseClipboard() };
+        image
     }
 
     #[link(name = "kernel32")]
@@ -327,8 +450,8 @@ mod imp {
     use objc2::runtime::{AnyClass, AnyObject, ProtocolObject};
     use objc2::{ClassType, MainThreadMarker};
     use objc2_app_kit::{
-        NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypeString, NSPasteboardURLReadingFileURLsOnlyKey,
-        NSPasteboardWriting,
+        NSBitmapImageFileType, NSBitmapImageRep, NSPasteboard, NSPasteboardReadingOptionKey, NSPasteboardTypePNG,
+        NSPasteboardTypeString, NSPasteboardTypeTIFF, NSPasteboardURLReadingFileURLsOnlyKey, NSPasteboardWriting,
     };
     use objc2_foundation::{NSArray, NSDictionary, NSNumber, NSString, NSURL};
     use std::path::PathBuf;
@@ -380,6 +503,33 @@ mod imp {
         })
     }
 
+    pub fn has_image() -> bool {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
+        autoreleasepool(|_| {
+            // SAFETY: the types are AppKit constants, valid for the process' lifetime.
+            let types = NSArray::from_slice(&[unsafe { NSPasteboardTypePNG }, unsafe { NSPasteboardTypeTIFF }]);
+            NSPasteboard::generalPasteboard().availableTypeFromArray(&types).is_some()
+        })
+    }
+
+    /// PNG as copied, else TIFF (what macOS screenshots and most apps write) converted.
+    pub fn png() -> Option<Vec<u8>> {
+        debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
+        autoreleasepool(|_| {
+            let board = NSPasteboard::generalPasteboard();
+            // SAFETY: the types are AppKit constants, valid for the process' lifetime.
+            if let Some(png) = board.dataForType(unsafe { NSPasteboardTypePNG }) {
+                return Some(png.to_vec());
+            }
+            let tiff = board.dataForType(unsafe { NSPasteboardTypeTIFF })?;
+            let image = NSBitmapImageRep::imageRepWithData(&tiff)?;
+            // SAFETY: an empty property dictionary is valid for every file type.
+            let png =
+                unsafe { image.representationUsingType_properties(NSBitmapImageFileType::PNG, &NSDictionary::new()) }?;
+            Some(png.to_vec())
+        })
+    }
+
     pub fn text() -> Option<String> {
         debug_assert!(MainThreadMarker::new().is_some(), "NSPasteboard access requires the main thread");
         autoreleasepool(|_| {
@@ -448,6 +598,17 @@ mod imp {
         false
     }
 
+    pub fn has_image() -> bool {
+        #[cfg(target_os = "linux")]
+        {
+            gtk::Clipboard::get(&gtk::gdk::SELECTION_CLIPBOARD).wait_is_image_available()
+        }
+        #[cfg(not(target_os = "linux"))]
+        {
+            false
+        }
+    }
+
     pub fn files() -> std::io::Result<Vec<PathBuf>> {
         Ok(Vec::new())
     }
@@ -521,4 +682,62 @@ mod tests {
         bytes.extend_from_slice(b"C:\\a\\b.txt\0C:\\c\0\0");
         assert_eq!(decode(&bytes), paths(&["C:\\a\\b.txt", "C:\\c"]));
     }
+
+    /// A `BITMAPINFOHEADER` DIB of `width` × `height` (positive: bottom-up).
+    fn dib(width: i32, height: i32, bits: u16, compression: u32, rows: &[&[u8]]) -> Vec<u8> {
+        let mut out = Vec::new();
+        out.extend_from_slice(&40u32.to_le_bytes());
+        out.extend_from_slice(&width.to_le_bytes());
+        out.extend_from_slice(&height.to_le_bytes());
+        out.extend_from_slice(&1u16.to_le_bytes());
+        out.extend_from_slice(&bits.to_le_bytes());
+        out.extend_from_slice(&compression.to_le_bytes());
+        out.extend_from_slice(&[0u8; 20]);
+        if compression == super::BI_BITFIELDS {
+            for mask in [0x00ff_0000u32, 0x0000_ff00, 0x0000_00ff] {
+                out.extend_from_slice(&mask.to_le_bytes());
+            }
+        }
+        for row in rows {
+            out.extend_from_slice(row);
+        }
+        out
+    }
+
+    fn decode_png(png: &[u8]) -> (u32, u32, Vec<u8>) {
+        let mut reader = png::Decoder::new(std::io::Cursor::new(png)).read_info().unwrap();
+        let mut buf = vec![0; reader.output_buffer_size().unwrap()];
+        let info = reader.next_frame(&mut buf).unwrap();
+        buf.truncate(info.buffer_size());
+        (info.width, info.height, buf)
+    }
+
+    #[test]
+    fn a_bottom_up_24_bit_bitmap_becomes_an_upright_opaque_png() {
+        // Rows are padded to 4 bytes; the first stored row is the bottom one.
+        let bottom: &[u8] = &[255, 0, 0, 0, 255, 0, 0, 0];
+        let top: &[u8] = &[0, 0, 255, 255, 255, 255, 0, 0];
+        let png = super::dib_to_png(&dib(2, 2, 24, super::BI_RGB, &[bottom, top])).unwrap();
+        let (w, h, rgba) = decode_png(&png);
+        assert_eq!((w, h), (2, 2));
+        assert_eq!(rgba, [255, 0, 0, 255, 255, 255, 255, 255, 0, 0, 255, 255, 0, 255, 0, 255]);
+    }
+
+    #[test]
+    fn a_32_bit_bitmap_keeps_its_alpha_unless_none_was_written() {
+        let row: &[u8] = &[10, 20, 30, 0, 40, 50, 60, 0];
+        let (_, _, rgba) = decode_png(&super::dib_to_png(&dib(2, -1, 32, super::BI_BITFIELDS, &[row])).unwrap());
+        assert_eq!(rgba, [30, 20, 10, 255, 60, 50, 40, 255]);
+        let row: &[u8] = &[10, 20, 30, 128, 40, 50, 60, 0];
+        let (_, _, rgba) = decode_png(&super::dib_to_png(&dib(2, -1, 32, super::BI_RGB, &[row])).unwrap());
+        assert_eq!(rgba, [30, 20, 10, 128, 60, 50, 40, 0]);
+    }
+
+    #[test]
+    fn unsupported_or_truncated_bitmaps_are_not_images() {
+        let row: &[u8] = &[1, 2, 3, 4];
+        assert!(super::dib_to_png(&dib(4, 1, 8, super::BI_RGB, &[row])).is_none());
+        assert!(super::dib_to_png(&dib(2, 2, 24, super::BI_RGB, &[row])).is_none());
+        assert!(super::dib_to_png(&[0; 10]).is_none());
+    }
 }

crates/ide-core/src/event.rs

@@ -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>,
     },

crates/ide-core/src/jsonc.rs

@@ -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);
+    }
 }

crates/ide-core/src/process.rs

@@ -141,6 +141,30 @@ pub fn process_tree(pid: i32) -> Vec<i32> {
     tree
 }
 
+/// Every process `pid` started, directly or not, parents before their children.
+pub fn descendants(pid: u32) -> Vec<u32> {
+    #[cfg(unix)]
+    {
+        let Ok(root) = i32::try_from(pid) else { return Vec::new() };
+        process_tree(root).into_iter().skip(1).filter_map(|p| u32::try_from(p).ok()).collect()
+    }
+    #[cfg(windows)]
+    {
+        use std::os::windows::io::AsRawHandle;
+        windows_tree::descendants(pid)
+            .iter()
+            // SAFETY: a live process handle opened with query access.
+            .map(|h| unsafe { windows_sys::Win32::System::Threading::GetProcessId(h.as_raw_handle()) })
+            .filter(|&p| p != 0)
+            .collect()
+    }
+    #[cfg(not(any(unix, windows)))]
+    {
+        let _ = pid;
+        Vec::new()
+    }
+}
+
 /// [`kill_tree`] that first asks the group to exit: `SIGTERM`, then `grace`, then `SIGKILL`.
 /// Git removes its `index.lock` on `SIGTERM`, where `SIGKILL` leaves it behind and the next
 /// git command fails. Windows has no such signal to send from outside the child's console,

crates/ide-core/src/settings.rs

@@ -86,6 +86,8 @@ pub struct AgentSettings {
     pub fold_turns: bool,
     /// Streaming text is revealed at a steady pace rather than chunk by chunk.
     pub smooth_text: bool,
+    /// Conversations and the composer expand to the full width of the pane instead of staying in a centred column.
+    pub fit_window_width: bool,
     #[serde(deserialize_with = "or_default")]
     #[specta(type = ThinkingDisplay)]
     pub thinking: ThinkingDisplay,
@@ -127,6 +129,7 @@ impl Default for AgentSettings {
             show_cost: false,
             fold_turns: true,
             smooth_text: true,
+            fit_window_width: false,
             thinking: ThinkingDisplay::Auto,
             tool_calls: ToolCallDisplay::Grouped,
             expand_tool_output: false,
@@ -1092,7 +1095,8 @@ 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,
@@ -1121,6 +1125,17 @@ 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 {
@@ -1542,6 +1557,16 @@ 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(
@@ -1693,11 +1718,15 @@ mod tests {
         let old: Settings = serde_json::from_str(r#"{"agents":{"showCost":true}}"#).unwrap();
         assert!(old.agents.show_cost);
         assert!(old.agents.show_context_usage && old.agents.show_work_time && old.agents.show_usage_limits);
+        assert!(!old.agents.fit_window_width);
         assert!(!Settings::default().agents.show_cost);
+        assert!(!Settings::default().agents.fit_window_width);
         let mut settings = Settings::default();
         settings.agents.show_usage_limits = false;
+        settings.agents.fit_window_width = true;
         let json = serde_json::to_value(&settings).unwrap();
         assert_eq!(json["agents"]["showUsageLimits"], false);
+        assert_eq!(json["agents"]["fitWindowWidth"], true);
         let restored: Settings = serde_json::from_value(json).unwrap();
         assert_eq!(restored.agents, settings.agents);
     }

crates/ide-dap/Cargo.toml

@@ -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

crates/ide-dap/src/attach.rs

@@ -405,6 +405,24 @@ pub fn attachable_processes() -> IdeResult<Vec<AttachableProcess>> {
     Ok(out)
 }
 
+/// The Attach to Process candidates among the processes `root` started, parents first.
+/// Blocking, like [`attachable_processes`].
+pub fn attachable_descendants(root: u32) -> IdeResult<Vec<AttachableProcess>> {
+    let order = ide_core::process::descendants(root);
+    if order.is_empty() {
+        return Ok(Vec::new());
+    }
+    let cwd = std::env::temp_dir();
+    let native = if adapter::resolve_binary("codelldb", &cwd).is_some() { "codelldb" } else { "lldb-dap" };
+    let mut out: Vec<AttachableProcess> = list_processes()?
+        .iter()
+        .filter(|p| order.contains(&p.pid))
+        .filter_map(|p| classify(p, is_dotnet, is_go_binary, native))
+        .collect();
+    out.sort_by_key(|p| order.iter().position(|&pid| pid == p.pid));
+    Ok(out)
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -418,6 +436,28 @@ mod tests {
             .map(|p| (p.kind, p.port))
     }
 
+    #[cfg(unix)]
+    #[test]
+    fn a_runs_candidates_are_the_processes_it_started() {
+        let mut child = std::process::Command::new("sh").args(["-c", "sleep 30; true"]).spawn().unwrap();
+        let deadline = std::time::Instant::now() + std::time::Duration::from_secs(10);
+        let found = loop {
+            let found = attachable_descendants(child.id()).unwrap();
+            if !found.is_empty() || std::time::Instant::now() > deadline {
+                break found;
+            }
+            std::thread::sleep(std::time::Duration::from_millis(50));
+        };
+        for p in &found {
+            let _ = std::process::Command::new("kill").arg(p.pid.to_string()).status();
+        }
+        child.kill().unwrap();
+        child.wait().unwrap();
+        assert!(found.iter().all(|p| p.pid != child.id()), "{found:?}");
+        assert!(found.iter().any(|p| p.name == "sleep" && p.kind == AttachKind::Native), "{found:?}");
+        assert!(attachable_descendants(u32::MAX - 1).unwrap().is_empty());
+    }
+
     #[test]
     fn parses_jdwp_agents() {
         let a = "java -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005 -jar app.jar";

crates/ide-dap/src/js_cdp.rs

@@ -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;
+    }
+}

crates/ide-dap/src/js_debug.rs

@@ -11,6 +11,8 @@ 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";
 
@@ -25,7 +27,7 @@ pub(crate) fn is_page(session: &Session) -> bool {
 /// 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.
-async fn launched(session: &Session) -> bool {
+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(_)))
@@ -59,6 +61,44 @@ impl DebugManager {
         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`).

crates/ide-dap/src/lib.rs

@@ -13,6 +13,7 @@ pub mod attach;
 mod cargo;
 pub mod connection;
 pub mod jdwp;
+mod js_cdp;
 mod js_debug;
 mod jvm_memory;
 pub mod kotlin;
@@ -24,6 +25,7 @@ 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;

crates/ide-dap/src/session.rs

@@ -94,6 +94,11 @@ pub(crate) struct Session {
     /// 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<()>,
@@ -255,6 +260,8 @@ impl Session {
             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(),
@@ -842,6 +849,10 @@ async fn on_event(mgr: &Arc<DebugManager>, s: &Arc<Session>, event: &str, mut bo
                 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}"),
     }
 }
@@ -872,6 +883,7 @@ fn on_reverse_request(mgr: &Arc<DebugManager>, s: &Arc<Session>, seq: i64, comma
 pub(crate) struct ProgramTerminal {
     writer: ide_core::input::InputWriter,
     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>,
@@ -884,6 +896,7 @@ impl ProgramTerminal {
     }
 
     /// 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 }
     }

crates/ide-dap/src/tests.rs

@@ -1104,6 +1104,142 @@ async fn a_page_whose_requests_the_adapter_does_not_report_says_so() {
     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]");

crates/ide-docker/src/lib.rs

@@ -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::*;

crates/ide-extension/src/manifest.rs

@@ -34,7 +34,7 @@ use std::path::{Component, Path, PathBuf};
 
 pub const MANIFEST_FILE: &str = "plugin.toml";
 /// The plugin API (engine) version this host implements.
-pub const ENGINE_VERSION: &str = "1.8.0";
+pub const ENGINE_VERSION: &str = "1.9.0";
 /// The 0.1 API, still accepted for contribution-only packages and 0.1 components.
 pub const LEGACY_API: &str = "0.1";
 /// Marketplace categories, in the order they are shown.

crates/ide-host/src/mcp/editors.rs

@@ -1,6 +1,10 @@
+use super::page::{OFFSET, Page};
 use super::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{Diagnostic, IdeResult, Severity};
-use serde_json::{Value, json};
+use serde_json::{Map, Value, json};
+
+/// Problems `get_project_problems` lists by default.
+const PROBLEMS_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![
@@ -37,7 +41,10 @@ Lines and UTF-16 columns are 1-based.",
 and inspections after profile filtering. This reflects what the Problems view shows, rather than a fresh analysis.
 Lines and UTF-16 columns are 1-based.",
             project_problems,
-        ),
+        )
+        .param(Param::optional("errorsOnly", ParamType::Boolean, "Only errors (default) or warnings too"))
+        .param(Param::optional("limit", ParamType::Integer, "Problems to return at most (default 100)"))
+        .param(Param::optional("offset", ParamType::Integer, OFFSET)),
     ]
 }
 
@@ -90,9 +97,25 @@ async fn file_problems(call: Call) -> IdeResult<Output> {
 }
 
 async fn project_problems(call: Call) -> IdeResult<Output> {
+    let page = Page::of(&call, PROBLEMS_LIMIT)?;
+    let errors_only = call.flag("errorsOnly", true)?;
     let files = call.host.mcp_reports.problems(&call.host.mcp_windows(call.root()));
-    let files: Vec<_> = files.into_iter().map(|f| json!({
-        "filePath":call.display(&f.path.0), "problems": f.items.into_iter().map(|d| problem(d, "")).collect::<Vec<_>>()
-    })).collect();
-    Output::json(json!({"files":files}))
+    let problems: Vec<(String, Value)> = files
+        .into_iter()
+        .flat_map(|f| {
+            let path = call.display(&f.path.0);
+            let wanted = f.items.into_iter().filter(|d| !errors_only || d.severity == Severity::Error);
+            wanted.map(move |d| (path.clone(), problem(d, "")))
+        })
+        .collect();
+    let mut out = Map::new();
+    let mut files: Vec<Value> = Vec::new();
+    for (path, problem) in page.take(problems, &mut out) {
+        match files.last_mut() {
+            Some(file) if file["filePath"] == path.as_str() => file["problems"].as_array_mut().unwrap().push(problem),
+            _ => files.push(json!({ "filePath": path, "problems": [problem] })),
+        }
+    }
+    out.insert("files".into(), files.into());
+    Output::json(Value::Object(out))
 }

crates/ide-host/src/mcp/files.rs

@@ -2,6 +2,7 @@
 // the list_directory_tree part of FileToolset.kt, src/com/intellij/mcpserver/util/fs.util.kt), Apache-2.0.
 //! Reading files and listing directories.
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use crate::mcp::util::{
     self, RELATIVE_PATH_IN_PROJECT_DESCRIPTION, TIMED_OUT_DESCRIPTION, TIMEOUT_MILLISECONDS_DESCRIPTION,
@@ -17,6 +18,8 @@ const MAX_READ_LIMIT: i64 = 5000;
 /// Longer lines are cut (minified files would flood the context), in UTF-16 units.
 const MAX_LINE_LENGTH: usize = 2000;
 const DEFAULT_TREE_DEPTH: i64 = 5;
+/// Entries `list_directory_tree` lists by default.
+const TREE_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![read_file(), list_directory_tree()]
@@ -149,6 +152,12 @@ struct DirectoryTreeInfo {
     errors: Vec<String>,
     #[serde(skip_serializing_if = "std::ops::Not::not")]
     listing_timed_out: bool,
+    /// Entries under the directory within `maxDepth`.
+    total: usize,
+    #[serde(skip_serializing_if = "std::ops::Not::not")]
+    more: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    next_offset: Option<usize>,
 }
 
 fn list_directory_tree() -> Tool {
@@ -156,10 +165,12 @@ fn list_directory_tree() -> Tool {
         "list_directory_tree",
         "Provides a tree representation of the specified directory in the pseudo graphic format like `tree` utility does.
 Use this tool to explore the contents of a directory or the whole project.
-You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.",
+You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.
+A page that starts inside a directory repeats the lines of the directories above it.",
         |call| async move {
             let directory = call.str("directoryPath")?;
             let max_depth = call.opt_i64("maxDepth")?.unwrap_or(DEFAULT_TREE_DEPTH);
+            let page = Page::of(&call, TREE_LIMIT)?;
             let timeout = call.opt_i64("timeout")?.unwrap_or(util::MEDIUM_TIMEOUT.as_millis() as i64);
             let dir = call.resolve_readable(&directory).await?;
             if !dir.exists() {
@@ -170,8 +181,16 @@ You MUST prefer this tool over listing directories via command line utilities li
             }
             let deadline = Instant::now() + Duration::from_millis(timeout.max(0) as u64);
             let cancel = call.cancel.clone();
-            let mut tree =
-                TreeRender { out: String::new(), errors: Vec::new(), timed_out: false, deadline, cancel: cancel.clone() };
+            let mut tree = TreeRender {
+                out: String::new(),
+                errors: Vec::new(),
+                timed_out: false,
+                deadline,
+                cancel: cancel.clone(),
+                page,
+                seen: 0,
+                above: Vec::new(),
+            };
             let tree = call
                 .host()
                 .blocking(move || {
@@ -187,11 +206,16 @@ You MUST prefer this tool over listing directories via command line utilities li
                 tree: tree.out,
                 errors: tree.errors,
                 listing_timed_out: tree.timed_out,
+                total: tree.seen,
+                more: tree.seen > page.end(),
+                next_offset: (tree.seen > page.end()).then_some(page.end()),
             })
         },
     )
     .param(Param::required("directoryPath", ParamType::String, RELATIVE_PATH_IN_PROJECT_DESCRIPTION))
     .param(Param::optional("maxDepth", ParamType::Integer, "Maximum recursion depth"))
+    .param(Param::optional("limit", ParamType::Integer, "Entries to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("timeout", ParamType::Integer, TIMEOUT_MILLISECONDS_DESCRIPTION))
     .output(json!({
         "type": "object",
@@ -200,19 +224,28 @@ You MUST prefer this tool over listing directories via command line utilities li
             "tree": { "type": "string" },
             "errors": { "type": "array", "items": { "type": "string" } },
             "listingTimedOut": { "type": "boolean", "description": TIMED_OUT_DESCRIPTION },
+            "total": { "type": "integer" },
+            "more": { "type": "boolean" },
+            "nextOffset": { "type": "integer" },
         },
-        "required": ["traversedDirectory", "tree", "errors"],
+        "required": ["traversedDirectory", "tree", "errors", "total"],
     }))
 }
 
 /// The `tree`-like listing: the directory's absolute path, then every entry (hidden and
-/// ignored ones too) by lower-cased name, directories marked with `/`.
+/// ignored ones too) by lower-cased name, directories marked with `/`; entries outside the
+/// page are counted, not listed.
 struct TreeRender {
     out: String,
     errors: Vec<String>,
     timed_out: bool,
     deadline: Instant,
     cancel: CancellationToken,
+    page: Page,
+    /// Entries met so far.
+    seen: usize,
+    /// The lines of the directories above the entry, and whether this page shows them yet.
+    above: Vec<(String, bool)>,
 }
 
 impl TreeRender {
@@ -235,7 +268,13 @@ impl TreeRender {
             path.file_name().unwrap_or_default().to_string_lossy().into_owned()
         };
         let is_dir = path.is_dir() && !path.is_symlink();
-        self.out.push_str(&format!("{indent}{prefix}{name}{}\n", if is_dir { "/" } else { "" }));
+        let line = format!("{indent}{prefix}{name}{}\n", if is_dir { "/" } else { "" });
+        let shown = if is_root {
+            self.out.push_str(&line);
+            true
+        } else {
+            self.entry(&line)
+        };
         if !is_dir {
             return;
         }
@@ -250,9 +289,32 @@ impl TreeRender {
         children.sort_by_cached_key(|p| (key(p).to_lowercase(), key(p)));
         let child_indent = format!("{indent}{}", if is_last { "    " } else { "│   " });
         let n = children.len();
+        if !is_root {
+            self.above.push((line, shown));
+        }
         for (i, child) in children.iter().enumerate() {
             self.render(child, &child_indent, i + 1 == n, max_depth - 1, false);
         }
+        if !is_root {
+            self.above.pop();
+        }
+    }
+
+    /// Counts an entry and lists it when on the page, after the directories above it.
+    fn entry(&mut self, line: &str) -> bool {
+        let n = self.seen;
+        self.seen += 1;
+        if n < self.page.offset || n >= self.page.end() {
+            return false;
+        }
+        for (above, shown) in &mut self.above {
+            if !*shown {
+                self.out.push_str(above);
+                *shown = true;
+            }
+        }
+        self.out.push_str(line);
+        true
     }
 }
 
@@ -302,4 +364,36 @@ mod tests {
         let short = format!("{}😀", "x".repeat(1998));
         assert_eq!(format_line(&short), short);
     }
+
+    #[test]
+    fn a_tree_page_repeats_the_directories_above_it() {
+        let tmp = tempfile::tempdir().unwrap();
+        for file in ["a/x.txt", "a/y.txt", "b.txt"] {
+            let path = tmp.path().join(file);
+            std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+            std::fs::write(path, "").unwrap();
+        }
+        let render = |offset, limit| {
+            let mut tree = TreeRender {
+                out: String::new(),
+                errors: Vec::new(),
+                timed_out: false,
+                deadline: Instant::now() + Duration::from_secs(10),
+                cancel: CancellationToken::new(),
+                page: Page { offset, limit },
+                seen: 0,
+                above: Vec::new(),
+            };
+            tree.render(tmp.path(), "", true, 5, true);
+            let root = format!("{}/\n", tmp.path().display());
+            (tree.out.strip_prefix(&root).unwrap().to_owned(), tree.seen)
+        };
+        assert_eq!(render(0, 2), ("    ├── a/\n    │   ├── x.txt\n".to_owned(), 4));
+        assert_eq!(
+            render(2, 2).0,
+            "    ├── a/\n    │   └── y.txt\n    └── b.txt\n",
+            "the page in `a/` repeats its line"
+        );
+        assert_eq!(render(0, 100).0, "    ├── a/\n    │   ├── x.txt\n    │   └── y.txt\n    └── b.txt\n");
+    }
 }

crates/ide-host/src/mcp/mod.rs

@@ -7,6 +7,7 @@ pub(crate) mod run;
 mod vcs;
 pub use requests::Requests;
 mod files;
+mod page;
 mod reports;
 mod search;
 mod symbols;

crates/ide-host/src/mcp/page.rs

@@ -0,0 +1,71 @@
+//! `limit` and `offset` of the tools that list things: a few items by default, the rest page by page.
+
+use super::tool::Call;
+use ide_core::{IdeError, IdeResult};
+use serde_json::{Map, Value};
+
+/// The most items one call returns.
+pub const MAX_LIMIT: usize = 1000;
+pub const OFFSET: &str = "Items to skip: `nextOffset` of the previous page";
+
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub struct Page {
+    pub offset: usize,
+    pub limit: usize,
+}
+
+impl Page {
+    /// The `limit` (`default` when absent, at most [`MAX_LIMIT`]) and `offset` (0) arguments.
+    pub fn of(call: &Call, default: usize) -> IdeResult<Self> {
+        let limit = match call.opt_i64("limit")? {
+            None => default,
+            Some(n) if n <= 0 => return Err(IdeError::invalid("limit must be > 0")),
+            Some(n) => (n as usize).min(MAX_LIMIT),
+        };
+        let offset = match call.opt_i64("offset")? {
+            None => 0,
+            Some(n) if n < 0 => return Err(IdeError::invalid("offset must be >= 0")),
+            Some(n) => n as usize,
+        };
+        Ok(Self { offset, limit })
+    }
+
+    /// Where the page ends: the items to find for it.
+    pub fn end(&self) -> usize {
+        self.offset.saturating_add(self.limit)
+    }
+
+    /// This page of all the `items`; `out` gets their `total`, and `more` and `nextOffset` when some follow.
+    pub fn take<T>(&self, items: Vec<T>, out: &mut Map<String, Value>) -> Vec<T> {
+        let total = items.len();
+        out.insert("total".into(), total.into());
+        self.mark(total > self.end(), out);
+        items.into_iter().skip(self.offset).take(self.limit).collect()
+    }
+
+    /// `more` and `nextOffset` when items follow the page.
+    pub fn mark(&self, more: bool, out: &mut Map<String, Value>) {
+        if more {
+            out.insert("more".into(), true.into());
+            out.insert("nextOffset".into(), self.end().into());
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn pages_say_what_follows() {
+        let page = |offset, limit| Page { offset, limit };
+        let mut out = Map::new();
+        assert_eq!(page(0, 2).take(vec![1, 2, 3, 4, 5], &mut out), [1, 2]);
+        assert_eq!(Value::Object(out), serde_json::json!({ "total": 5, "more": true, "nextOffset": 2 }));
+        let mut out = Map::new();
+        assert_eq!(page(4, 2).take(vec![1, 2, 3, 4, 5], &mut out), [5]);
+        assert_eq!(Value::Object(out), serde_json::json!({ "total": 5 }), "the last page");
+        let mut out = Map::new();
+        assert!(page(9, 2).take(vec![1], &mut out).is_empty());
+    }
+}

crates/ide-host/src/mcp/run/agent_tools.rs

@@ -3,6 +3,7 @@
 
 use super::agent::{AgentRun, INTERVENTION_ADVICE, TruncateMode, clean_output, tab_name, truncate_lines};
 use super::output::RUN_PREVIEW_MAX_LENGTH;
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::run::timeout;
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{IdeError, IdeResult};
@@ -35,6 +36,14 @@ and `nextOffset` are positions in the tab's raw output log; pass `nextOffset` as
 const MAX_LINES: &str = "Lines of output to return at most (default 2000)";
 const TRUNCATE_MODE: &str = "Which lines to leave out beyond maxLinesCount: START (default, keeps the end), END \
 (keeps the start), MIDDLE (keeps both ends) or NONE";
+/// `list_runs`: tabs returned by default, and characters of each command, enough to tell them apart.
+const LIST_LIMIT: usize = 10;
+const LIST_COMMAND_CHARS: usize = 80;
+const LIST_STATES: [(&str, &[&str]); 3] = [
+    ("running", &["starting", "running", "stopping"]),
+    ("idle", &["succeeded", "failed", "crashed", "stoppedByAgent", "stoppedByUser", "startFailed"]),
+    ("error", &["failed", "crashed", "startFailed"]),
+];
 
 fn find(call: &Call) -> IdeResult<Arc<AgentRun>> {
     let name = tab_name(&call.str("name")?)?;
@@ -283,13 +292,64 @@ for input) and `tabClosedAt` when the user closed the tab.{INTERVENTIONS}"
 pub fn list_runs() -> Tool {
     Tool::new(
         "list_runs",
-        "Lists the agent tabs of the project (those started by `run_command`) with their status.",
+        "Lists the agent tabs of the project (those started by `run_command`), newest first: name, state, the \
+start of the command, exit code and times. `get_run_status` gives a tab's whole status.",
         |call| async move {
-            let runs: Vec<Value> =
-                call.host().mcp_agent_runs.list(call.root()).iter().map(|r| Value::Object(r.status())).collect();
-            Output::json(serde_json::json!({ "runs": runs }))
+            let page = Page::of(&call, LIST_LIMIT)?;
+            let wanted = call.opt_str("state")?.filter(|s| s != "all");
+            let states = match wanted.as_deref() {
+                None => None,
+                Some(s) => Some(match LIST_STATES.iter().find(|(group, _)| *group == s) {
+                    Some((_, states)) => states.to_vec(),
+                    None if LIST_STATES[1].1.contains(&s) || LIST_STATES[0].1.contains(&s) => vec![s],
+                    None => {
+                        return Err(IdeError::invalid(format!(
+                            "unknown state `{s}`: all, running, idle, error, or one of the states of get_run_status"
+                        )));
+                    }
+                }),
+            };
+            let runs: Vec<Value> = call
+                .host()
+                .mcp_agent_runs
+                .list(call.root())
+                .iter()
+                .rev()
+                .map(|r| r.status())
+                .filter(|s| {
+                    states.as_ref().is_none_or(|states| s["state"].as_str().is_some_and(|v| states.contains(&v)))
+                })
+                .map(|s| Value::Object(brief(s)))
+                .collect();
+            let mut out = Map::new();
+            let runs = page.take(runs, &mut out);
+            out.insert("runs".into(), runs.into());
+            Output::json(Value::Object(out))
         },
     )
+    .param(Param::optional(
+        "state",
+        ParamType::String,
+        "all (default), running, idle (not running), error (failed, crashed, startFailed), or one state",
+    ))
+    .param(Param::optional("limit", ParamType::Integer, "Tabs to return at most (default 10)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
+}
+
+/// A tab in `list_runs`: what tells it apart and how it went, the command cut short.
+fn brief(mut status: Map<String, Value>) -> Map<String, Value> {
+    let mut out = Map::new();
+    for key in ["name", "state", "command", "exitCode", "crash", "error", "startedAt", "endedAt", "tabClosedAt"] {
+        if let Some(v) = status.remove(key) {
+            out.insert(key.into(), v);
+        }
+    }
+    if let Some(Value::String(command)) = out.get_mut("command")
+        && command.chars().count() > LIST_COMMAND_CHARS
+    {
+        *command = format!("{}…", command.chars().take(LIST_COMMAND_CHARS).collect::<String>());
+    }
+    out
 }
 
 /// What a key does to a command on pipes.
@@ -407,6 +467,22 @@ pub fn tools() -> Vec<Tool> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn listed_tabs_are_brief_and_their_commands_cut_short() {
+        let status = serde_json::json!({
+            "name": "_agent_build", "state": "failed", "command": "x".repeat(100), "exitCode": 1,
+            "workingDirectory": "", "outputLength": 9, "startedBy": "agent",
+        });
+        let Value::Object(status) = status else { unreachable!() };
+        let brief = Value::Object(brief(status));
+        assert_eq!(brief["command"].as_str().unwrap(), format!("{}…", "x".repeat(LIST_COMMAND_CHARS)));
+        assert_eq!(
+            (&brief["name"], &brief["state"], &brief["exitCode"]),
+            (&"_agent_build".into(), &"failed".into(), &1.into())
+        );
+        assert!(brief.get("outputLength").is_none() && brief.get("workingDirectory").is_none());
+    }
+
     #[test]
     fn keys_are_what_pipes_can_take() {
         assert_eq!(key(" enter ").unwrap(), Key::Text("\n"));

crates/ide-host/src/mcp/run/configs.rs

@@ -7,6 +7,7 @@ use super::output::OutputCollector;
 use super::process::{quote, split_words};
 use super::targets;
 use crate::Project;
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::run::timeout;
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_build::compile::BuildKind;
@@ -19,6 +20,8 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 const DEFAULT_TIMEOUT_MS: usize = 10_000;
+/// Configurations `get_run_configurations` lists by default.
+const CONFIGURATIONS_LIMIT: usize = 100;
 /// Output of a failed before-launch process kept for the error message.
 const MAX_PROCESS_OUTPUT_LENGTH: usize = 20_000;
 /// A before-launch build gets this long.
@@ -50,7 +53,8 @@ fn describe_config(call: &Call, c: &RunConfig) -> Value {
         if let Some(cwd) = c.cwd.as_deref() {
             v["workingDirectory"] = call.display(&call.root().join(cwd)).into();
         }
-        if !c.env.is_empty() {
+        // A detected configuration's environment is the IDE's own (its tools on `PATH`).
+        if !c.env.is_empty() && !c.detected {
             v["environment"] = json!(c.env);
         }
     }
@@ -133,8 +137,23 @@ the whole command. Run points are found in Rust, JavaScript/TypeScript, Python a
                 .await?;
                 return Output::json(json!({ "filePath": file, "runPoints": points }));
             }
-            let list: Vec<Value> = configs.iter().map(|c| describe_config(&call, c)).collect();
-            Output::json(json!({ "configurations": list }))
+            let page = Page::of(&call, CONFIGURATIONS_LIMIT)?;
+            let query = call.opt_str("query")?.map(|q| q.to_lowercase());
+            let list: Vec<Value> = configs
+                .iter()
+                .filter(|c| {
+                    query.as_ref().is_none_or(|q| {
+                        [c.name.as_str(), c.kind.as_str(), command_line(c).as_str()]
+                            .iter()
+                            .any(|s| s.to_lowercase().contains(q.as_str()))
+                    })
+                })
+                .map(|c| describe_config(&call, c))
+                .collect();
+            let mut out = Map::new();
+            let list = page.take(list, &mut out);
+            out.insert("configurations".into(), list.into());
+            Output::json(Value::Object(out))
         },
     )
     .write()
@@ -144,6 +163,9 @@ the whole command. Run points are found in Rust, JavaScript/TypeScript, Python a
         "Optional file path relative to the project root. When provided, returns run points (executable entry points) \
 in the file instead of project-wide run configurations.",
     ))
+    .param(Param::optional("query", ParamType::String, "Only configurations whose name, type or command contains it"))
+    .param(Param::optional("limit", ParamType::Integer, "Configurations to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
 }
 
 /// What `execute_run_configuration` runs.

crates/ide-host/src/mcp/search.rs

@@ -5,6 +5,7 @@
 //! Coordinates are 1-based, end exclusive; columns count UTF-16 code units like
 //! the editor (one per character except emoji and other astral characters).
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use crate::mcp::util::{INDEXING_PARTIAL_RESULT_REASON, MEDIUM_TIMEOUT};
 use crate::ops::search::SearchEvent;
@@ -21,8 +22,8 @@ use std::sync::Arc;
 use std::time::{Duration, Instant};
 
 pub const MAX_RESULTS_UPPER_BOUND: usize = 5000;
-const DEFAULT_LIMIT: i64 = 1000;
-pub const SYMBOL_SEARCH_DEFAULT_LIMIT: i64 = 50;
+const DEFAULT_LIMIT: usize = 100;
+pub const SYMBOL_SEARCH_DEFAULT_LIMIT: usize = 50;
 pub const SEARCH_TIMEOUT_PARTIAL_RESULT_REASON: &str =
     "The search timed out after 10 s. Narrow the query or pass paths.";
 /// Symbols requested from the index per result when `paths` filters them afterwards.
@@ -37,7 +38,8 @@ const LINE_WINDOW: usize = 500;
 
 const PATHS_DESCRIPTION: &str = "Optional list of project-relative glob patterns to filter results. Supports '!' \
 excludes. Trailing '/' expands to '**'. Patterns without '/' are treated as '**/pattern'. Empty strings are ignored.";
-const LIMIT_DESCRIPTION: &str = "Maximum number of results to return";
+const LIMIT_DESCRIPTION: &str = "Results to return at most (default 100)";
+const SYMBOL_LIMIT_DESCRIPTION: &str = "Results to return at most (default 50)";
 const CONTEXT_DESCRIPTION: &str = "Lines around each match to return besides the matched line (`lineText`): \"+N\" the \
 N lines after it (`contextAfter`), \"-N\" the N lines before it (`contextBefore`), \"N\" (or the number N) N lines on \
 each side. At most 50. Default: the matched line only.";
@@ -67,6 +69,7 @@ Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
     .param(Param::required("q", ParamType::String, "Text to search for"))
     .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -88,6 +91,7 @@ Examples: [\"src/**\", \"!**/test/**\"], [\"**/*.kt\"], [\"foo/\"].",
     .param(Param::required("q", ParamType::String, "Regex pattern to search for"))
     .param(Param::optional("paths", ParamType::StringList, PATHS_DESCRIPTION))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -113,7 +117,8 @@ If you don't find a suitable result, try again with include_external=true to sea
         "Whether to include SDK and library symbols. Disabled by default; if nothing suitable is found, try again \
 with include_external=true.",
     ))
-    .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("limit", ParamType::Integer, SYMBOL_LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .param(Param::optional("context", ParamType::String, CONTEXT_DESCRIPTION))
     .output(result_schema())
 }
@@ -138,6 +143,7 @@ Paths are optional additional glob filters relative to the project root.",
         "Whether to include excluded/ignored files in results",
     ))
     .param(Param::optional("limit", ParamType::Integer, LIMIT_DESCRIPTION))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
     .output(result_schema())
 }
 
@@ -191,6 +197,9 @@ struct SearchResult {
     items: Vec<SearchItem>,
     #[serde(skip_serializing_if = "std::ops::Not::not")]
     more: bool,
+    /// The `offset` of the next page, when `more`.
+    #[serde(skip_serializing_if = "Option::is_none")]
+    next_offset: Option<usize>,
     #[serde(skip_serializing_if = "Option::is_none")]
     partial_result_reason: Option<&'static str>,
 }
@@ -212,16 +221,23 @@ fn result_schema() -> Value {
                 "required": ["filePath"],
             } },
             "more": { "type": "boolean" },
+            "nextOffset": int,
             "partialResultReason": string,
         },
     })
 }
 
-fn limit(call: &Call, default: i64) -> IdeResult<usize> {
-    match call.opt_i64("limit")?.unwrap_or(default) {
-        n if n <= 0 => Err(IdeError::invalid("limit must be > 0")),
-        n => Ok((n as usize).min(MAX_RESULTS_UPPER_BOUND)),
-    }
+/// The page of `call` and the results to find for it: up to its end.
+fn page(call: &Call, default: usize) -> IdeResult<(Page, usize)> {
+    let page = Page::of(call, default)?;
+    Ok((page, page.end().min(MAX_RESULTS_UPPER_BOUND)))
+}
+
+/// Drops the results before the page, and the `nextOffset` when more follow. A search finds
+/// [`MAX_RESULTS_UPPER_BOUND`] results at most, so no page starts past them.
+fn skip<T>(page: Page, items: &mut Vec<T>, more: bool) -> Option<usize> {
+    items.drain(..page.offset.min(items.len()));
+    (more && page.end() < MAX_RESULTS_UPPER_BOUND).then_some(page.end())
 }
 
 fn query(call: &Call, empty: &str) -> IdeResult<String> {
@@ -521,7 +537,7 @@ struct TextHit {
 
 async fn text_search(call: Call, is_regex: bool) -> IdeResult<Output> {
     let pattern = query(&call, if is_regex { "Regex pattern is empty" } else { "Search text is empty" })?;
-    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, DEFAULT_LIMIT)?;
     let around = context(&call)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     // Globs Find in Files cannot take are applied afterwards, so the engine must not
@@ -612,11 +628,12 @@ async fn text_search(call: Call, is_regex: bool) -> IdeResult<Output> {
             ..Default::default()
         })
         .collect();
+    let next_offset = skip(page, &mut items, more);
     let absolute: std::collections::HashMap<&str, &Path> =
         files.iter().map(|(path, file)| (path.as_str(), file.path.0.as_path())).collect();
     fill_lines(&call, &mut items, |item| absolute.get(item.file_path.as_str()).map(|p| p.to_path_buf()), around).await;
     let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 /// The matches of `ranges` (byte ranges in `text`) that start on 0-based `line`, with their
@@ -721,7 +738,7 @@ async fn run_search(call: &Call, query: SearchQuery) -> IdeResult<(Vec<FileMatch
 
 async fn file_search(call: Call) -> IdeResult<Output> {
     let q = query(&call, "Glob pattern is empty")?;
-    let limit = limit(&call, DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, DEFAULT_LIMIT)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     let include_excluded = call.flag("includeExcluded", false)?;
     let glob = GlobSetBuilder::new()
@@ -759,9 +776,11 @@ async fn file_search(call: Call) -> IdeResult<Output> {
             Ok((found, more, walk.timed_out.get()))
         })
         .await?;
-    let items = paths.into_iter().map(|file_path| SearchItem { file_path, ..Default::default() }).collect();
+    let mut items: Vec<SearchItem> =
+        paths.into_iter().map(|file_path| SearchItem { file_path, ..Default::default() }).collect();
+    let next_offset = skip(page, &mut items, more);
     let partial_result_reason = timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON);
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 struct Walk {
@@ -835,7 +854,7 @@ impl Walk {
 async fn symbol_search(call: Call) -> IdeResult<Output> {
     let started = Instant::now();
     let q = query(&call, "Search query is empty")?;
-    let limit = limit(&call, SYMBOL_SEARCH_DEFAULT_LIMIT)?;
+    let (page, limit) = page(&call, SYMBOL_SEARCH_DEFAULT_LIMIT)?;
     let around = context(&call)?;
     let scope = PathScope::new(call.root(), &call.str_list("paths")?)?;
     let external = call.flag("include_external", false)?;
@@ -886,6 +905,7 @@ async fn symbol_search(call: Call) -> IdeResult<Output> {
     }
     let more = items.len() > limit || timed_out;
     items.truncate(limit);
+    let next_offset = skip(page, &mut items, more);
     // Project files (relative paths, or absolute ones of content roots); library URIs are left out.
     let root = call.root().to_path_buf();
     let absolute = |item: &SearchItem| {
@@ -899,7 +919,7 @@ async fn symbol_search(call: Call) -> IdeResult<Output> {
     } else {
         timed_out.then_some(SEARCH_TIMEOUT_PARTIAL_RESULT_REASON)
     };
-    Output::json(SearchResult { items, more, partial_result_reason })
+    Output::json(SearchResult { items, more, next_offset, partial_result_reason })
 }
 
 /// The language servers' workspace symbols, and whether `budget` ran out first; empty

crates/ide-host/src/mcp/symbols.rs

@@ -210,6 +210,7 @@ fn leads_declaration(line: &str, line_comment: Option<&str>) -> bool {
 pub fn find_references() -> Tool {
     Tool::new("find_references", "Find references using the language service and the IDE's project index. Positions are 1-based UTF-16. Reports incomplete results when analysis is still running.", |call| async move {
         let path = call.resolve_readable(&call.str("filePath")?).await?;
+        let page = super::page::Page::of(&call, REFERENCES_LIMIT)?;
         let line = call.opt_i64("line")?.ok_or_else(|| IdeError::invalid("missing line"))?;
         let column = call.opt_i64("column")?.ok_or_else(|| IdeError::invalid("missing column"))?;
         let project = call.project.clone();
@@ -244,14 +245,28 @@ pub fn find_references() -> Tool {
             }
         }
         positions(&mut value);
+        // `classified`, when there, goes with `locations` one to one.
+        if let serde_json::Value::Object(map) = &mut value {
+            let mut list = |key: &str| match map.remove(key) { Some(serde_json::Value::Array(items)) => items, _ => Vec::new() };
+            let (locations, classified) = (list("locations"), list("classified"));
+            let classified = page.take(classified, &mut serde_json::Map::new());
+            let locations = page.take(locations, map);
+            map.insert("locations".into(), locations.into());
+            map.insert("classified".into(), classified.into());
+        }
         Output::json(value)
     })
     .param(Param::required("filePath", ParamType::String, "Path relative to the project root"))
     .param(Param::required("line", ParamType::Integer, "1-based line"))
     .param(Param::required("column", ParamType::Integer, "1-based UTF-16 column"))
     .param(Param::optional("includeDeclaration", ParamType::Boolean, "Include declarations (default true)"))
+    .param(Param::optional("limit", ParamType::Integer, "References to return at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, super::page::OFFSET))
 }
 
+/// References `find_references` lists by default.
+const REFERENCES_LIMIT: usize = 100;
+
 fn mcp_position(text: &str, line: i64, column: i64) -> IdeResult<Pos> {
     if line < 1 || line > u32::MAX as i64 || column < 1 || column > u32::MAX as i64 {
         return Err(IdeError::invalid("line and column must be positive 1-based positions"));

crates/ide-host/src/mcp/vcs.rs

@@ -2,12 +2,13 @@
 // (mcpserver.vcs/src/com/intellij/mcpserver/toolsets/vcs/VcsToolset.kt), Apache-2.0.
 //! Version control: repositories and git status.
 
+use crate::mcp::page::{OFFSET, Page};
 use crate::mcp::tool::{Call, Output, Param, ParamType, Tool};
 use ide_core::{IdeError, IdeResult};
 use serde_json::{Value, json};
 use std::path::{Path, PathBuf};
 
-const STATUS_DEFAULT_LIMIT: i64 = 1000;
+const STATUS_DEFAULT_LIMIT: usize = 100;
 
 pub fn tools() -> Vec<Tool> {
     vec![get_repositories(), git_status(), git_diff()]
@@ -254,11 +255,7 @@ By default all Git repositories are returned.",
         |call| async move {
             let include_untracked = call.flag("includeUntracked", true)?;
             let include_ignored = call.flag("includeIgnored", false)?;
-            let limit = call.opt_i64("limit")?.unwrap_or(STATUS_DEFAULT_LIMIT);
-            if limit <= 0 {
-                return Err(IdeError::invalid("limit must be > 0"));
-            }
-            let limit = limit as usize;
+            let page = Page::of(&call, STATUS_DEFAULT_LIMIT)?;
             let host = call.host();
             let h = host.clone();
             let w = call.window.clone();
@@ -305,7 +302,8 @@ By default all Git repositories are returned.",
                 let count = |f: fn(&StatusEntry) -> bool| entries.iter().filter(|e| f(e)).count();
                 let listed: Vec<Value> = entries
                     .iter()
-                    .take(limit)
+                    .skip(page.offset)
+                    .take(page.limit)
                     .map(|e| {
                         let mut v = json!({
                             "pathRelativeToRepository": e.path.trim_end_matches('/'),
@@ -318,19 +316,24 @@ By default all Git repositories are returned.",
                         v
                     })
                     .collect();
-                repositories.push(json!({
+                let more = entries.len() > page.end();
+                let mut repository = json!({
                     "repositoryPathRelativeToProject": rel,
                     "currentBranch": branch,
                     "isClean": entries.is_empty(),
                     "totalEntries": entries.len(),
-                    "hasMoreEntries": entries.len() > listed.len(),
+                    "hasMoreEntries": more,
                     "stagedCount": count(StatusEntry::staged),
                     "unstagedCount": count(StatusEntry::unstaged),
                     "untrackedCount": count(StatusEntry::untracked),
                     "ignoredCount": count(StatusEntry::ignored),
                     "conflictedCount": count(StatusEntry::conflicted),
                     "entries": listed,
-                }));
+                });
+                if more {
+                    repository["nextOffset"] = page.end().into();
+                }
+                repositories.push(repository);
             }
             Output::json(json!({ "repositories": repositories }))
         },
@@ -342,7 +345,8 @@ By default all Git repositories are returned.",
     ))
     .param(Param::optional("includeUntracked", ParamType::Boolean, "Whether to include untracked files"))
     .param(Param::optional("includeIgnored", ParamType::Boolean, "Whether to include ignored files"))
-    .param(Param::optional("limit", ParamType::Integer, "Maximum number of entries returned per repository"))
+    .param(Param::optional("limit", ParamType::Integer, "Entries to return per repository at most (default 100)"))
+    .param(Param::optional("offset", ParamType::Integer, OFFSET))
 }
 
 fn git_diff() -> Tool {

crates/ide-host/src/ops/agent.rs

@@ -261,6 +261,18 @@ pub async fn fork(host: &Host, window: &str, task: String, turns: Option<u32>) -
     host.project(window)?.agents.fork(&task, turns).await
 }
 
+/// Creates a temporary side conversation of `source`: lives in memory only, never
+/// persisted, not listed.
+pub async fn create_ephemeral(
+    host: &Host,
+    window: &str,
+    request: NewAgentTask,
+    source: String,
+) -> IdeResult<AgentTask> {
+    host.require_trust(window)?;
+    host.project(window)?.agents.create_ephemeral(request, &source).await
+}
+
 /// Drops the task's turns after its first `turns`; returns the message of the first dropped one.
 pub async fn rollback(host: &Host, window: &str, task: String, turns: u32) -> IdeResult<Option<AgentPrompt>> {
     host.require_trust(window)?;

crates/ide-host/src/ops/debug.rs

@@ -382,6 +382,15 @@ pub async fn debug_js_custom_breakpoints(
     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,
@@ -391,6 +400,18 @@ pub async fn debug_js_response_body(
     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)
 }
@@ -607,12 +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
     });

crates/ide-host/src/ops/doc.rs

@@ -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)

crates/ide-host/src/ops/doc/commands.rs

@@ -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
     });

crates/ide-host/src/ops/lsp.rs

@@ -1472,6 +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())
 }
@@ -1856,6 +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 });

crates/ide-host/src/ops/project.rs

@@ -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() {

crates/ide-host/src/ops/run.rs

@@ -508,7 +508,7 @@ pub fn list(host: &Host) -> Vec<RunInfo> {
 }
 
 mod commands;
-mod container;
+pub(crate) mod container;
 pub use commands::*;
 
 #[cfg(test)]

crates/ide-host/src/ops/run/container.rs

@@ -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);

crates/ide-host/src/ops/sdk.rs

@@ -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",

crates/ide-host/src/ops/sdk/container_python.rs

@@ -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))
+}

crates/ide-host/src/plugins/api.rs

@@ -3047,7 +3047,16 @@ impl PluginWorkspace for HostWorkspace {
             &project.root,
             &project.settings.effective(),
         );
-        if config.debug_adapter.is_none() {
+        if config.debug_adapter.is_none()
+            && let Some(language) = config.extras.params.get(super::run_detectors::DEBUG_LANGUAGE)
+        {
+            config.debug_adapter = project
+                .languages
+                .get(&ide_core::LanguageId::new(language.as_str()))
+                .and_then(|l| l.debugger)
+                .map(|d| d.adapter);
+        }
+        if config.debug_adapter.is_none() && !config.extras.params.contains_key(super::run_detectors::DEBUG_ATTACH) {
             let cwd = config.cwd.as_ref().map(|p| p.as_ref()).unwrap_or(&project.root);
             config.debug_adapter =
                 config.args.iter().map(|arg| cwd.join(arg)).filter(|path| path.is_file()).find_map(|path| {

crates/ide-host/src/plugins/execution.rs

@@ -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)?;
     }
@@ -402,6 +415,67 @@ fn validate_configurations(
         if let Some(cwd) = &c.cwd {
             ide_plugin::resolve_new_in_root(root, cwd).map_err(HostError::Invalid)?;
         }
+        validate_env(&c.env)?;
+        validate_debugger(c.debugger.as_ref())?;
+    }
+    Ok(())
+}
+
+/// Like `process` commands, a configuration only adds variables: one the IDE's own
+/// environment has (`PATH`, …) would change what the approved program runs.
+fn validate_env(env: &[(String, String)]) -> Result<(), HostError> {
+    if env.len() > 64 {
+        return Err(HostError::Invalid("at most 64 environment variables".into()));
+    }
+    let mut names = std::collections::BTreeSet::new();
+    for (name, value) in env {
+        if name.is_empty() || name.len() > 256 || name.contains(['=', '\0']) {
+            return Err(HostError::Invalid(format!("{name:?} is not an environment variable name")));
+        }
+        if value.len() > 4096 || value.contains('\0') {
+            return Err(HostError::Invalid(format!("the value of {name:?} is too long or holds a NUL")));
+        }
+        let key = if cfg!(windows) { name.to_ascii_uppercase() } else { name.clone() };
+        if !names.insert(key) || inherited_env(name) {
+            return Err(HostError::Invalid(format!(
+                "environment variable {name:?} is repeated or already set; only new variables may be added"
+            )));
+        }
+    }
+    Ok(())
+}
+
+fn inherited_env(name: &str) -> bool {
+    std::env::vars_os().any(|(inherited, _)| {
+        if cfg!(windows) { inherited.to_string_lossy().eq_ignore_ascii_case(name) } else { inherited == name }
+    })
+}
+
+/// Attach to Process kinds a configuration may attach to.
+pub(super) const ATTACH_KINDS: [&str; 5] = ["dotnet", "node", "python", "go", "native"];
+
+fn validate_debugger(debugger: Option<&ide_plugin::PluginDebugger>) -> Result<(), HostError> {
+    match debugger {
+        Some(ide_plugin::PluginDebugger::Launch { language }) => {
+            if language.is_empty()
+                || language.len() > 64
+                || !language.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '-' | '_' | '.'))
+            {
+                return Err(HostError::Invalid(format!("{language:?} is not a language id")));
+            }
+        }
+        Some(ide_plugin::PluginDebugger::AttachChild { kind, command_contains }) => {
+            if !ATTACH_KINDS.contains(&kind.as_str()) {
+                return Err(HostError::Invalid(format!(
+                    "attach-child kind {kind:?} is not one of {}",
+                    ATTACH_KINDS.join(", ")
+                )));
+            }
+            if command_contains.as_ref().is_some_and(|t| t.is_empty() || t.len() > 256 || t.contains('\0')) {
+                return Err(HostError::Invalid("attach-child command-contains must be 1-256 bytes".into()));
+            }
+        }
+        None => {}
     }
     Ok(())
 }
@@ -518,6 +592,52 @@ impl PluginHost {
     }
 }
 
+impl PluginHost {
+    /// The process an `attach-child` configuration's debugger attaches to: the first Attach to
+    /// Process candidate of its kind that `run` (a run of this configuration) started, waited
+    /// for while the run lasts, up to a minute. Only the run's own descendants are candidates.
+    pub fn debug_attach_target(
+        &self,
+        host: &crate::Host,
+        client: &str,
+        config: &str,
+        run: ide_core::RunId,
+    ) -> IdeResult<ide_dap::attach::AttachableProcess> {
+        use super::run_detectors::{DEBUG_ATTACH, DEBUG_ATTACH_CONTAINS};
+        let Some((plugin, id)) = config.strip_prefix(ide_run::EXTERNAL_PREFIX).and_then(|s| s.split_once(':')) else {
+            return Err(IdeError::invalid("not a plugin configuration"));
+        };
+        let workspace = self.shared.workspace().ok_or_else(IdeError::cancelled)?;
+        let owned = workspace.run_configuration(client, plugin, id).map_err(|e| IdeError::invalid(e.to_string()))?;
+        let kind = owned
+            .extras
+            .params
+            .get(DEBUG_ATTACH)
+            .filter(|k| ATTACH_KINDS.contains(&k.as_str()))
+            .ok_or_else(|| IdeError::invalid("this configuration does not attach to a process"))?
+            .clone();
+        let contains = owned.extras.params.get(DEBUG_ATTACH_CONTAINS).cloned();
+        let deadline = Instant::now() + Duration::from_secs(60);
+        loop {
+            let info = crate::ops::run::list(host).into_iter().find(|r| r.id == run && r.config_id == owned.id);
+            let Some(pid) = info.as_ref().filter(|r| r.running).and_then(|r| r.pid) else {
+                return Err(IdeError::not_found("the run ended before a process to debug started"));
+            };
+            let found = ide_dap::attach::attachable_descendants(pid)?.into_iter().find(|p| {
+                serde_json::to_value(p.kind).ok().and_then(|v| v.as_str().map(|k| k == kind)) == Some(true)
+                    && contains.as_ref().is_none_or(|t| p.command_line.contains(t.as_str()))
+            });
+            if let Some(process) = found {
+                return Ok(process);
+            }
+            if Instant::now() >= deadline {
+                return Err(IdeError::not_found(format!("no {kind} process started by the run within a minute")));
+            }
+            std::thread::sleep(Duration::from_millis(500));
+        }
+    }
+}
+
 /// Internal launch metadata; it is ignored after the original operation finishes.
 pub(super) const RUN_OPERATION: &str = "plugin.operation";
 impl PluginHost {
@@ -571,3 +691,73 @@ 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"))
+        );
+    }
+
+    fn launch(
+        env: Vec<(&str, &str)>,
+        debugger: Option<ide_plugin::PluginDebugger>,
+    ) -> ide_plugin::PluginRunConfiguration {
+        ide_plugin::PluginRunConfiguration {
+            id: "app".into(),
+            name: "App".into(),
+            program: "tool".into(),
+            env: env.into_iter().map(|(k, v)| (k.into(), v.into())).collect(),
+            debugger,
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn configurations_only_add_environment_variables() {
+        let root = std::env::temp_dir();
+        let ok = |c| validate_configurations(&root, &[c]).is_ok();
+        assert!(ok(launch(vec![("OPENIDEA_TEST_NEW_VARIABLE", "1")], None)));
+        let (inherited, _) = std::env::vars().next().expect("the test runs with an environment");
+        assert!(!ok(launch(vec![(inherited.as_str(), "x")], None)));
+        assert!(!ok(launch(vec![("A_B", "1"), ("A_B", "2")], None)));
+        for name in ["", "A=B", "A\0"] {
+            assert!(!ok(launch(vec![(name, "1")], None)), "{name:?}");
+        }
+        assert!(!ok(launch(vec![("OPENIDEA_TEST_NUL", "a\0")], None)));
+        let many: Vec<_> = (0..65).map(|i| (format!("OPENIDEA_TEST_{i}"), String::new())).collect();
+        let mut config = launch(vec![], None);
+        config.env = many;
+        assert!(!ok(config));
+    }
+
+    #[test]
+    fn configurations_name_a_language_or_an_attach_to_process_kind() {
+        use ide_plugin::PluginDebugger::{AttachChild, Launch};
+        let root = std::env::temp_dir();
+        let ok = |d| validate_configurations(&root, &[launch(vec![], Some(d))]).is_ok();
+        assert!(ok(Launch { language: "csharp".into() }));
+        assert!(!ok(Launch { language: String::new() }));
+        assert!(!ok(Launch { language: "c sharp".into() }));
+        for kind in ATTACH_KINDS {
+            assert!(ok(AttachChild { kind: kind.into(), command_contains: None }), "{kind}");
+        }
+        assert!(!ok(AttachChild { kind: "java".into(), command_contains: None }));
+        assert!(ok(AttachChild { kind: "dotnet".into(), command_contains: Some("Worker.dll".into()) }));
+        assert!(!ok(AttachChild { kind: "dotnet".into(), command_contains: Some(String::new()) }));
+    }
+}

crates/ide-host/src/plugins/remote_host.rs

@@ -57,6 +57,7 @@ pub const COMMANDS: &[&str] = &[
     "plugin_terminal_session_close",
     "plugin_terminal_session_spawn",
     "plugin_prepare_debug_run",
+    "plugin_debug_attach_target",
     "plugin_finish_operation",
     "plugin_content_tab_action",
     "plugin_post_events",
@@ -572,6 +573,15 @@ impl RemotePlugins {
             }
         });
         let h = host.clone();
+        d.add("plugin_debug_attach_target", move |c| {
+            let h = h.clone();
+            async move {
+                let plugins = alive(&h)?;
+                let (config, run) = (c.arg::<String>("config")?, c.arg("run")?);
+                blocking(move || plugins.debug_attach_target(&c.host, &c.window, &config, run)).await
+            }
+        });
+        let h = host.clone();
         d.add("plugin_finish_operation", move |c| {
             let h = h.clone();
             async move {

crates/ide-host/src/plugins/run_detectors.rs

@@ -130,6 +130,11 @@ pub struct PluginRunDetection {
     pub(crate) project_pins: super::api::ProjectPins,
 }
 
+/// `RunConfig.extras.params` keys carrying an API 1.9 configuration's debugger.
+pub const DEBUG_LANGUAGE: &str = "debugLanguage";
+pub const DEBUG_ATTACH: &str = "debugAttach";
+pub const DEBUG_ATTACH_CONTAINS: &str = "debugAttachContains";
+
 pub(super) fn config_id(plugin: &str, detector: &str) -> String {
     format!("{EXTERNAL_PREFIX}{plugin}:{detector}")
 }
@@ -195,6 +200,19 @@ impl ExternalDetection for PluginRunDetection {
                 if let Some(framework) = &c.framework {
                     config.extras.params.insert("framework".into(), framework.clone());
                 }
+                config.env = c.env.iter().cloned().collect();
+                match &c.debugger {
+                    Some(ide_plugin::PluginDebugger::Launch { language }) => {
+                        config.extras.params.insert(DEBUG_LANGUAGE.into(), language.clone());
+                    }
+                    Some(ide_plugin::PluginDebugger::AttachChild { kind, command_contains }) => {
+                        config.extras.params.insert(DEBUG_ATTACH.into(), kind.clone());
+                        if let Some(text) = command_contains {
+                            config.extras.params.insert(DEBUG_ATTACH_CONTAINS.into(), text.clone());
+                        }
+                    }
+                    None => {}
+                }
                 configs.push(config);
             }
         }

crates/ide-host/src/project.rs

@@ -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 {
@@ -620,6 +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);
@@ -630,6 +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)
     }
 
@@ -701,12 +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);
@@ -725,7 +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(
@@ -771,8 +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)
     }
 }
@@ -1456,7 +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(),
@@ -1478,6 +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()))

crates/ide-host/src/rpc.rs

@@ -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
         })

crates/ide-host/src/trust.rs

@@ -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(())
@@ -341,6 +342,7 @@ pub fn restricted_command_allowed(cmd: &str) -> bool {
             | "clear_caches"
             | "clipboard_file_list"
             | "clipboard_has_files"
+            | "clipboard_has_image"
             | "clipboard_image"
             | "clipboard_set_file_list"
             | "clipboard_write_text"
@@ -400,6 +402,7 @@ 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"

crates/ide-host/tests/container_python_real.rs

@@ -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();
+}

crates/ide-host/tests/light_edit.rs

@@ -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;
+}

crates/ide-host/tests/mcp.rs

@@ -110,6 +110,11 @@ async fn reads_unsaved_text_and_searches_the_overlay_with_a_limit() {
     let found = h.json("search_text", json!({"q":"needle","limit":2})).await;
     assert_eq!(found["items"].as_array().unwrap().len(), 2);
     assert_eq!(found["more"], true);
+    assert_eq!(found["nextOffset"], 2);
+    // The next page goes on where this one ended.
+    let every = h.json("search_text", json!({"q":"needle","limit":20})).await["items"].as_array().unwrap().clone();
+    let next = h.json("search_text", json!({"q":"needle","limit":2,"offset":2})).await;
+    assert_eq!(next["items"].as_array().unwrap()[..], every[2..every.len().min(4)]);
     let all = h.json("search_text", json!({"q":"fresh","limit":20})).await;
     assert_eq!(all["items"][0]["filePath"], "src/a.txt");
     // The matched line comes with the result (unsaved text included), and lines around it on request.
@@ -162,7 +167,9 @@ async fn window_reports_supply_editor_selection_and_problems_then_disappear_on_c
     assert_eq!(focused["selection"]["startColumn"], 3);
     let problems = h.json("get_file_problems", json!({"filePath":"src/a.txt","errorsOnly":false})).await;
     assert_eq!(problems["errors"][0]["description"], "reported warning");
-    assert_eq!(h.json("get_project_problems", json!({})).await["files"].as_array().unwrap().len(), 1);
+    assert_eq!(h.json("get_project_problems", json!({})).await["files"], json!([]), "errors only by default");
+    let all = h.json("get_project_problems", json!({"errorsOnly":false})).await;
+    assert_eq!((all["files"].as_array().unwrap().len(), &all["total"]), (1, &json!(1)));
     h.host.close_project("main");
     h.host.open_project("main", &h.root).unwrap();
     assert_eq!(h.json("get_all_open_file_paths", json!({})).await["openFiles"], json!([]));
@@ -287,6 +294,41 @@ async fn execution_requires_a_window_and_denial_never_runs_a_build() {
     assert!(error.contains("window closed"), "{error}");
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn run_configurations_are_listed_a_page_at_a_time_and_filtered() {
+    let h = Harness::new();
+    h.trust().await;
+    let saved = |name: &str, command: &str, env: &[(&str, &str)]| ide_run::RunConfig {
+        id: format!("user:{name}"),
+        name: name.into(),
+        kind: "shell".into(),
+        command: command.into(),
+        args: Vec::new(),
+        cwd: None,
+        env: env.iter().map(|(k, v)| ((*k).to_owned(), (*v).to_owned())).collect(),
+        detected: false,
+        is_test: false,
+        debug_adapter: None,
+        allow_parallel: false,
+        extras: Default::default(),
+    };
+    let configs =
+        [saved("build", "tsc", &[("MODE", "ci")]), saved("lint", "oxlint .", &[]), saved("test", "vitest", &[])];
+    ide_run::save_user_configs(&h.root, &configs).unwrap();
+    let all = h.json("get_run_configurations", json!({})).await;
+    let total = all["total"].as_u64().unwrap();
+    assert!(total >= 3, "{all}");
+    // A saved configuration's own environment is listed.
+    let build = all["configurations"].as_array().unwrap().iter().find(|c| c["name"] == "build").unwrap();
+    assert_eq!(build["environment"], json!({ "MODE": "ci" }));
+    let first = h.json("get_run_configurations", json!({"limit": 1})).await;
+    assert_eq!((first["configurations"].as_array().unwrap().len(), &first["nextOffset"]), (1, &json!(1)));
+    let lint = h.json("get_run_configurations", json!({"query": "OXLINT"})).await;
+    let found = lint["configurations"].as_array().unwrap();
+    assert!(!found.is_empty() && (found.len() as u64) < total, "{lint}");
+    assert!(found.iter().all(|c| c.to_string().to_lowercase().contains("oxlint")), "{lint}");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn git_status_and_diff_on_a_temporary_repository() {
     let h = Harness::new();
@@ -308,6 +350,18 @@ async fn git_status_and_diff_on_a_temporary_repository() {
     std::fs::write(h.root.join("src/a.txt"), "changed\n").unwrap();
     let status = h.json("git_status", json!({"repositoryPathRelativeToProject":"."})).await;
     assert_eq!(status["repositories"][0]["unstagedCount"], 1);
+    // Two entries, one per page.
+    std::fs::write(h.root.join("src/new.txt"), "new\n").unwrap();
+    let page =
+        |offset: u64| h.json("git_status", json!({"repositoryPathRelativeToProject":".","limit":1,"offset":offset}));
+    let first = page(0).await["repositories"][0].clone();
+    assert_eq!(
+        (&first["totalEntries"], &first["hasMoreEntries"], &first["nextOffset"]),
+        (&json!(2), &json!(true), &json!(1))
+    );
+    let second = page(1).await["repositories"][0].clone();
+    assert_ne!(second["entries"][0], first["entries"][0]);
+    assert!(second.get("nextOffset").is_none(), "{second}");
     assert!(h.call("git_diff", json!({"filePath":"src/a.txt"})).await.contains("+changed"));
     assert!(h.call("git_diff", json!({})).await.contains("src/a.txt"));
     assert!(h.call("git_diff", json!({"staged":true})).await.is_empty());
@@ -610,6 +664,19 @@ async fn agent_commands_run_in_named_tabs_and_report_what_the_user_did() {
     assert!(from_start["output"].as_str().unwrap().contains("hello"), "one log across the tab's commands");
     let runs = h.json("list_runs", json!({})).await;
     assert_eq!(runs["runs"].as_array().unwrap().len(), 2, "{runs}");
+    // Newest first, brief, filtered by state and paged.
+    let newest = h.json("list_runs", json!({"limit": 1})).await;
+    assert_eq!(
+        (&newest["runs"][0]["name"], &newest["total"], &newest["nextOffset"]),
+        (&json!("_agent_server"), &json!(2), &json!(1))
+    );
+    assert!(newest["runs"][0].get("outputLength").is_none(), "{newest}");
+    assert_eq!(h.json("list_runs", json!({"state": "idle"})).await["total"], 2);
+    assert_eq!(h.json("list_runs", json!({"state": "running"})).await["total"], 0);
+    assert_eq!(h.json("list_runs", json!({"state": "stoppedByAgent"})).await["total"], 2);
+    assert_eq!(h.json("list_runs", json!({"state": "error"})).await["total"], 0);
+    let unknown = h.error("list_runs", json!({"state": "done"})).await;
+    assert!(unknown.contains("unknown state `done`"), "{unknown}");
     let missing = h.error("get_run_status", json!({"name": "nothing"})).await;
     assert!(missing.contains("no agent tab named `_agent_nothing`"), "{missing}");
 

crates/ide-host/tests/plugins.rs

@@ -6450,7 +6450,13 @@ fn api14_stage3_configurations_test_results_and_content_actions_use_real_exports
     let configs = f.host.run_detection().detect(&f.project);
     assert!(configs.iter().any(|c| c.id == "plugin:execution:dynamic"
         && c.is_test
-        && c.extras.params.get("framework").map(String::as_str) == Some("plugin")));
+        && c.extras.params.get("framework").map(String::as_str) == Some("plugin")
+        && c.env.get("OPENIDEA_EXECUTION_FIXTURE").map(String::as_str) == Some("1")
+        && c.extras.params.get("debugLanguage").map(String::as_str) == Some("python")));
+    let worker = configs.iter().find(|c| c.id == "plugin:execution:worker").unwrap();
+    assert_eq!(worker.extras.params.get("debugAttach").map(String::as_str), Some("dotnet"));
+    assert_eq!(worker.extras.params.get("debugAttachContains").map(String::as_str), Some("Worker.dll"));
+    assert!(worker.env.is_empty() && !worker.is_test);
     assert_eq!(
         f.host.parse_test_results("main", "plugin:execution:dynamic", "batch".into()).unwrap().unwrap().len(),
         3

crates/ide-host/tests/trust.rs

@@ -46,6 +46,7 @@ async fn application_commands_work_in_restricted_projects_and_without_a_project(
         "clear_caches",
         "clipboard_file_list",
         "clipboard_has_files",
+        "clipboard_has_image",
         "clipboard_image",
         "clipboard_set_file_list",
         "clipboard_write_text",

crates/ide-host/tests/vcs_flow.rs

@@ -207,3 +207,22 @@ async fn change_commit_branch_stash_and_merge_a_conflict() {
     assert!(f.status().await.is_empty());
     assert_eq!(std::fs::read_to_string(&lib_path).unwrap(), resolved);
 }
+
+#[tokio::test(flavor = "multi_thread", worker_threads = 4)]
+async fn checkout_reports_a_branch_held_by_another_worktree() {
+    let f = Flow::new("rust-app").await;
+    let linked = f._tmp.path().join("linked");
+    git(&f.root, &["worktree", "add", "-q", "-b", "topic", linked.to_str().unwrap()]);
+
+    let outcome = ops::vcs::vcs_checkout(&f.host, WINDOW, None, "topic".into(), false, None).await.unwrap();
+    assert_eq!(
+        outcome,
+        ide_vcs::CheckoutOutcome::CheckedOutInWorktree {
+            branch: "topic".into(),
+            path: dunce::canonicalize(&linked).unwrap()
+        }
+    );
+    // Nothing changed: the project is still on main.
+    let branches = ops::vcs::vcs_branches(&f.host, WINDOW, None).await.unwrap();
+    assert!(branches.iter().any(|b| b.name == "main" && b.current), "{branches:?}");
+}

crates/ide-index/src/store.rs

@@ -599,6 +599,28 @@ impl Store {
         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.ensure_db()?;

crates/ide-index/src/worker.rs

@@ -17,6 +17,8 @@ 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);
@@ -436,10 +438,13 @@ impl Shared {
         });
 
         let filter = self.filter();
+        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();
@@ -452,6 +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 {
@@ -462,33 +468,76 @@ 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}");
             }
@@ -506,54 +555,85 @@ 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) {
@@ -594,6 +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 {
@@ -793,6 +882,33 @@ enum Extracted {
     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;

crates/ide-jsonrpc/src/output.rs

@@ -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);
+    }
 }

crates/ide-language/queries/bash/highlights.scm

@@ -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

crates/ide-language/src/lib.rs

@@ -28,6 +28,7 @@ pub use syntax::{
     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>,

crates/ide-language/src/syntax/grammars.rs

@@ -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,

crates/ide-language/src/syntax/highlight.rs

@@ -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 [

crates/ide-language/src/syntax/inheritance.rs

@@ -43,7 +43,7 @@ fn extract(tree: &Tree, text: &str) -> Vec<ClassBases> {
         // 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 = node.child_by_field_name("superclasses").map(|args| base_names(args, text)).unwrap_or_default();
+        let bases = class_base_names(node, text);
         out.push(ClassBases { name, line: range.start.line, col: range.start.col, bases });
     });
     out
@@ -67,6 +67,11 @@ fn visit(cursor: &mut tree_sitter::TreeCursor, f: &mut impl FnMut(Node)) {
     }
 }
 
+/// 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();

crates/ide-language/src/syntax/mod.rs

@@ -10,6 +10,7 @@ mod inheritance;
 pub(crate) mod lines;
 mod literals;
 mod outline;
+mod python_facts;
 mod rst;
 mod selection;
 mod sfc;
@@ -27,6 +28,7 @@ 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;

crates/ide-language/src/syntax/python_facts.rs

@@ -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);
+    }
+}

crates/ide-lsp/src/handler.rs

@@ -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) {
@@ -251,18 +275,24 @@ impl ClientHandler {
 
     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 {
@@ -480,7 +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);

crates/ide-lsp/src/injections.rs

@@ -715,33 +715,35 @@ mod tests {
         server.set_diagnostics(a.path.clone(), vec![diag(2, 5, "a"), diag(0, 1, "outside"), diag(4, 6, "crosses")]);
         let items = server.set_diagnostics(b.path.clone(), vec![diag(7, 10, "b")]);
         mgr.emit_diagnostics(&server, b.path, items, Encoding::Utf16);
-        let latest = || {
-            events
-                .lock()
-                .iter()
-                .rev()
-                .find_map(|e| match e {
+        // The SQL server's failed launch reports its status from a runtime thread; while that
+        // thread drains the server's event queue, events emitted here reach the sink from it.
+        let latest = |want: &dyn Fn(&[ide_core::Diagnostic]) -> bool| {
+            let deadline = std::time::Instant::now() + Duration::from_secs(5);
+            loop {
+                let items = events.lock().iter().rev().find_map(|e| match e {
                     ide_core::IdeEvent::Diagnostics { path: p, source, items }
                         if p.0 == path && source == &server.name =>
                     {
                         Some(items.clone())
                     }
                     _ => None,
-                })
-                .unwrap()
+                });
+                match items {
+                    Some(items) if want(&items) => return items,
+                    _ if std::time::Instant::now() > deadline => panic!("latest host diagnostics: {items:?}"),
+                    _ => std::thread::sleep(Duration::from_millis(5)),
+                }
+            }
         };
-        assert_eq!(latest().iter().map(|d| d.message.as_str()).collect::<Vec<_>>().len(), 3);
+        let messages = |items: &[ide_core::Diagnostic]| items.iter().map(|d| d.message.clone()).collect::<Vec<_>>();
+        let merged = latest(&|items| items.len() == 3);
         assert!(
-            latest()
-                .iter()
-                .filter(|d| d.message != "native")
-                .all(|d| d.source.as_deref() == Some(server.name.as_str()))
+            merged.iter().filter(|d| d.message != "native").all(|d| d.source.as_deref() == Some(server.name.as_str()))
         );
         mgr.set_injections(host, 1, vec![injection(7, 10)]);
-        assert_eq!(latest().iter().map(|d| d.message.clone()).collect::<Vec<_>>(), ["native", "b"]);
+        latest(&|items| messages(items) == ["native", "b"]);
         mgr.set_injections(host, 1, vec![]);
-        assert_eq!(latest()[0].message, "native");
-        assert_eq!(latest().len(), 1);
+        latest(&|items| messages(items) == ["native"]);
         assert!(
             events.lock().iter().all(|e| !matches!(e, ide_core::IdeEvent::Diagnostics { path, .. } if reserved(path)))
         );

crates/ide-lsp/src/launch.rs

@@ -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);
     }

crates/ide-lsp/src/lib.rs

@@ -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,
@@ -1718,6 +1767,38 @@ impl LspManager {
         }
     }
 
+    /// Library classes in `jar:` targets that have no cached sources jar: the official Kotlin
+    /// LSP decompiles them to signatures only (`/* compiled code */`). When jdtls is running,
+    /// the same class from its Java model instead, decompiled with method bodies and navigable.
+    /// Its documents belong to jdtls ([`Self::virtual_document`] records it).
+    async fn jdt_library_classes(&self, snap: &DocSnap, pos: Pos, locs: Vec<Location>) -> Vec<Location> {
+        let jar_class = |l: &Location| l.uri.as_deref().is_some_and(|u| u.starts_with("jar:") && u.ends_with(".class"));
+        if !locs.iter().any(jar_class)
+            || !self.servers.lock().iter().any(|s| s.name == jdtls::SERVER && s.running().is_some())
+        {
+            return locs;
+        }
+        let name = library_source::identifier_at(snap.text.line(pos.line as usize), pos.col).map(str::to_owned);
+        let mut out = Vec::with_capacity(locs.len());
+        for loc in locs {
+            let entry = loc.uri.as_deref().filter(|_| jar_class(&loc)).and_then(library_source::parse);
+            let Some(entry) = entry else {
+                out.push(loc);
+                continue;
+            };
+            let Ok(uri) = self.java_class_file(Path::new(""), Some((entry.jar, entry.entry))).await else {
+                out.push(loc);
+                continue;
+            };
+            let range = match (&name, self.virtual_document(&uri).await) {
+                (Some(name), Ok(doc)) => library_source::declaration_range(&doc.text, name),
+                _ => Range::default(),
+            };
+            out.push(Location { path: uri.clone().into(), range, uri: Some(uri) });
+        }
+        out
+    }
+
     async fn goto_in(
         &self,
         snap: &DocSnap,
@@ -1759,6 +1840,7 @@ impl LspManager {
                     let locs = library_sources(snap, &self.project_root, pos, locs).await;
                     self.note_virtual(&t.server, locs.iter().map(|l| l.uri.as_deref()));
                     self.note_arduino_sources(&t.server, &locs);
+                    let locs = self.jdt_library_classes(snap, pos, locs).await;
                     let locs = merge_locations(first, locs);
                     if !locs.is_empty() {
                         return Ok(locs);
@@ -2892,11 +2974,10 @@ 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 +3008,8 @@ 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 +3030,7 @@ 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 +3179,21 @@ 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 +3952,41 @@ 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))))
             }

crates/ide-lsp/src/library_source.rs

@@ -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");
@@ -513,6 +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())
         };
@@ -523,6 +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"), "");
     }

crates/ide-lsp/src/pull.rs

@@ -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;

crates/ide-lsp/src/server.rs

@@ -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();

crates/ide-lsp/src/types.rs

@@ -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

crates/ide-lsp/src/virtual_doc.rs

@@ -32,7 +32,7 @@ pub(crate) fn normalize_uris(value: &mut serde_json::Value) {
                 if matches!(key.as_str(), "data" | "arguments") {
                     continue;
                 }
-                if matches!(key.as_str(), "uri" | "targetUri" | "oldUri" | "newUri")
+                if matches!(key.as_str(), "uri" | "targetUri" | "oldUri" | "newUri" | "target")
                     && let Some(uri) = value.as_str().and_then(escaped_uri)
                 {
                     *value = uri.into();
@@ -247,6 +247,22 @@ mod tests {
         assert!(encoded.parse::<lsp_types::Uri>().is_ok());
     }
 
+    /// `DocumentLink.target` is a URI too: one unescaped link fails the whole `documentLink` response.
+    #[test]
+    fn document_link_targets_are_escaped() {
+        let range = serde_json::json!({ "start": { "line": 0, "character": 0 }, "end": { "line": 0, "character": 1 } });
+        let mut links = serde_json::json!([
+            { "range": range, "target": "file:///D:/My Game/项目/a.xsd" },
+            { "range": range, "target": "https://example.com/a b" }
+        ]);
+        assert!(serde_json::from_value::<Vec<lsp_types::DocumentLink>>(links.clone()).is_err());
+        normalize_uris(&mut links);
+        assert_eq!(links[0]["target"], "file:///D:/My%20Game/%E9%A1%B9%E7%9B%AE/a.xsd");
+        assert_eq!(links[1]["target"], "https://example.com/a b", "other schemes are not touched");
+        links[1]["target"] = "https://example.com/ab".into();
+        assert_eq!(serde_json::from_value::<Vec<lsp_types::DocumentLink>>(links).unwrap().len(), 2);
+    }
+
     /// #3089: jdtls's Introduce Variable edit for a project under a Chinese path names the file
     /// with the characters unescaped, and the resolved code action failed to deserialize.
     #[test]

crates/ide-lsp/tests/mock_server.rs

@@ -146,6 +146,9 @@ impl Handler for MockHandler {
                 if let Some(gate) = gate {
                     gate.hold();
                 }
+                if let Some(error) = s.errors.lock().get("initialize").cloned() {
+                    return Err(error);
+                }
                 Ok(json!({ "capabilities": s.caps.lock().clone(), "serverInfo": { "name": "mock" } }))
             }
             "shutdown" => Ok(Value::Null),
@@ -268,6 +271,7 @@ fn server_cfg(name: &str) -> LanguageServerConfig {
         tsserver_project: false,
         tsserver_project_extras: Default::default(),
         resync_on_configuration: false,
+        display_name: None,
         pinned: None,
     }
 }
@@ -292,37 +296,48 @@ fn harness_configured(
     servers: &[(&str, Value)],
     adjust: impl Fn(&mut LanguageServerConfig),
 ) -> Harness {
+    harness_languages(&[(lang_id, ext, servers)], adjust)
+}
+
+/// A language as `(id, extension, servers)`.
+type MockLanguage<'a> = (&'a str, &'a str, &'a [(&'a str, Value)]);
+
+/// Several languages; documents open as the first.
+fn harness_languages(languages: &[MockLanguage<'_>], adjust: impl Fn(&mut LanguageServerConfig)) -> Harness {
     let dir = tempfile::tempdir().unwrap();
     // Edits and references report canonical paths.
     let root = dunce::canonicalize(dir.path()).unwrap();
-    let lang = LanguageConfig {
-        id: LanguageId::new(lang_id),
-        name: "Mock".into(),
-        extensions: vec![ext.into()],
-        filenames: vec![],
-        first_line: None,
-        line_comment: None,
-        block_comment: None,
-        indent: None,
-        ui_mode: None,
-        framework_ui_modes: Vec::new(),
-        framework_files: Vec::new(),
-        formatter: None,
-        scratch_template: None,
-        tree_sitter: None,
-        language_servers: servers
-            .iter()
-            .map(|(n, _)| {
-                let mut cfg = server_cfg(n);
-                adjust(&mut cfg);
-                cfg
-            })
-            .collect(),
-        debugger: None,
-    };
-    let registry = Arc::new(LanguageRegistry::from_configs(vec![lang]));
+    let configs = languages
+        .iter()
+        .map(|(lang_id, ext, servers)| LanguageConfig {
+            id: LanguageId::new(*lang_id),
+            name: "Mock".into(),
+            extensions: vec![ext.to_string()],
+            filenames: vec![],
+            first_line: None,
+            line_comment: None,
+            block_comment: None,
+            indent: None,
+            ui_mode: None,
+            framework_ui_modes: Vec::new(),
+            framework_files: Vec::new(),
+            formatter: None,
+            scratch_template: None,
+            tree_sitter: None,
+            language_servers: servers
+                .iter()
+                .map(|(n, _)| {
+                    let mut cfg = server_cfg(n);
+                    adjust(&mut cfg);
+                    cfg
+                })
+                .collect(),
+            debugger: None,
+        })
+        .collect();
+    let registry = Arc::new(LanguageRegistry::from_configs(configs));
     let launcher = Arc::new(MockLauncher::default());
-    for (name, caps) in servers {
+    for (name, caps) in languages.iter().flat_map(|(_, _, servers)| servers.iter()) {
         *launcher.state(name).caps.lock() = caps.clone();
     }
     let events = Arc::new(Mutex::new(Vec::new()));
@@ -331,7 +346,7 @@ fn harness_configured(
         Arc::new(move |e: IdeEvent| events.lock().push(e))
     };
     let mgr = LspManager::with_launcher(root.clone(), registry, sink, launcher.clone());
-    Harness { _dir: dir, root, mgr, launcher, events, lang: LanguageId::new(lang_id) }
+    Harness { _dir: dir, root, mgr, launcher, events, lang: LanguageId::new(languages[0].0) }
 }
 
 impl Harness {
@@ -2072,6 +2087,29 @@ async fn crash_restarts_and_reopens_documents() {
     assert_eq!(hover.contents.value, "hi");
 }
 
+/// A restart during a long start (a project import) returns when the instance is up and
+/// running, and does not hold up `reconfigure` and `shutdown_all` meanwhile.
+#[tokio::test(flavor = "multi_thread")]
+async fn restart_does_not_hold_the_reconfigure_lock_while_the_server_starts() {
+    let h = harness(&[("mock", incremental_caps())]);
+    h.open("a.mk", "x");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    let s = h.launcher.state("mock");
+    let gate = Arc::new(Gate::default());
+    *s.initialize_gate.lock() = Some(gate.clone());
+    let id = h.mgr.servers()[0].id;
+    let restart = tokio::spawn({
+        let mgr = h.mgr.clone();
+        async move { mgr.restart(id).await }
+    });
+    eventually(|| gate.entered()).await;
+    let reconfigured = tokio::time::timeout(Duration::from_secs(2), h.mgr.reconfigure()).await;
+    gate.open();
+    reconfigured.expect("a restart still waiting for the server to start must not block reconfigure");
+    restart.await.unwrap().unwrap();
+    assert_eq!(h.mgr.servers()[0].status, ServerStatus::Ready);
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn gives_up_after_repeated_crashes_and_manual_restart_works() {
     let h = harness(&[("mock", incremental_caps())]);
@@ -2099,6 +2137,118 @@ async fn gives_up_after_repeated_crashes_and_manual_restart_works() {
     assert_eq!(h.mgr.servers()[0].status, ServerStatus::Ready);
 }
 
+/// One malformed diagnostic costs only itself, not the file's other problems.
+#[tokio::test(flavor = "multi_thread")]
+async fn a_malformed_diagnostic_does_not_drop_the_others() {
+    let h = harness(&[("mock", incremental_caps())]);
+    let (_, path) = h.open("a.mk", "one");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    let uri = uri_of(&path);
+    let range = json!({"start":{"line":0,"character":0},"end":{"line":0,"character":1}});
+    h.launcher
+        .state("mock")
+        .peer()
+        .notify(
+            "textDocument/publishDiagnostics",
+            json!({ "uri": uri, "diagnostics": [
+                { "range": range, "message": "first" },
+                { "message": "no range" },
+                { "range": range, "message": 7 },
+                { "range": range, "message": "last" }] }),
+        )
+        .unwrap();
+    eventually(|| {
+        h.events.lock().iter().any(|e| match e {
+            IdeEvent::Diagnostics { items, .. } => {
+                items.iter().map(|d| d.message.as_str()).collect::<Vec<_>>() == ["first", "last"]
+            }
+            _ => false,
+        })
+    })
+    .await;
+}
+
+/// The `initialize` error is the crash report's reason, not "terminated unexpectedly", and
+/// a server that never gets past `initialize` gives up like any other crash loop.
+#[tokio::test(flavor = "multi_thread")]
+async fn a_failed_initialize_is_reported_with_its_reason_and_gives_up() {
+    let h = harness(&[("mock", incremental_caps())]);
+    let s = h.launcher.state("mock");
+    s.errors.lock().insert("initialize".into(), (-32603, "no workspace".into()));
+    h.open("a.mk", "x");
+    let count = |status| h.statuses("mock").iter().filter(|s| **s == status).count();
+    eventually(|| count(ServerStatus::Crashed) == 4).await;
+    let messages: Vec<String> = h
+        .events
+        .lock()
+        .iter()
+        .filter_map(|e| match e {
+            IdeEvent::LanguageServer { status: ServerStatus::Crashed, message, .. } => message.clone(),
+            _ => None,
+        })
+        .collect();
+    assert!(
+        messages[0].contains("failed to start: initialize failed (server error -32603: no workspace)"),
+        "{messages:?}"
+    );
+    assert!(messages[0].ends_with("Restarting…"));
+    assert!(messages[3].ends_with("restart it manually."), "{messages:?}");
+    tokio::time::sleep(Duration::from_millis(300)).await;
+    assert_eq!(s.launches.load(Ordering::SeqCst), 4, "initial start + 3 restarts");
+}
+
+/// The client tells servers it retries semantic tokens, inlay hints and code lens that they
+/// withdrew with `ContentModified` (`staleRequestSupport`), so it must.
+#[tokio::test(flavor = "multi_thread")]
+async fn withdrawn_editor_decoration_requests_are_asked_again() {
+    let h = harness(&[("mock", incremental_caps())]);
+    let (doc, _) = h.open("a.mk", "let x = 1");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    let s = h.launcher.state("mock");
+    let range = json!({"start":{"line":0,"character":0},"end":{"line":0,"character":1}});
+    let cases = [
+        ("textDocument/semanticTokens/full", json!({ "data": [0, 0, 1, 0, 0] })),
+        ("textDocument/inlayHint", json!([{ "position": {"line":0,"character":0}, "label": "x" }])),
+        ("textDocument/codeLens", json!([{ "range": range, "command": { "title": "t", "command": "c" } }])),
+    ];
+    for (method, answer) in cases {
+        s.errors.lock().insert(method.into(), (-32801, "content modified".into()));
+        let mgr = h.mgr.clone();
+        let request = tokio::spawn(async move {
+            match method {
+                "textDocument/semanticTokens/full" => mgr.semantic_tokens(doc).await.map(|r| r.is_some()),
+                "textDocument/inlayHint" => {
+                    mgr.inlay_hints(doc, Range::new(Pos::new(0, 0), Pos::new(0, 9))).await.map(|v| v.len() == 1)
+                }
+                _ => mgr.code_lens(doc).await.map(|v| v.len() == 1),
+            }
+        });
+        eventually(|| !s.requested(method).is_empty()).await;
+        s.errors.lock().remove(method);
+        s.respond(method, answer);
+        let answered = tokio::time::timeout(Duration::from_secs(5), request).await.unwrap().unwrap();
+        assert!(answered.unwrap_or(false), "{method} was not asked again");
+        assert_eq!(s.requested(method).len(), 2, "{method}");
+    }
+}
+
+/// A server disabled in settings while its crash backoff is still sleeping stays gone: the
+/// pending restart must not bring it back as a process nothing lists or stops.
+#[tokio::test(flavor = "multi_thread")]
+async fn a_server_disabled_during_its_crash_backoff_does_not_restart() {
+    let h = harness(&[("mock", incremental_caps()), ("other", incremental_caps())]);
+    h.open("a.mk", "x");
+    h.wait_status("mock", ServerStatus::Ready).await;
+    let s = h.launcher.state("mock");
+    s.peer().kill();
+    eventually(|| h.statuses("mock").contains(&ServerStatus::Crashed)).await;
+    h.mgr.set_servers_hook(Box::new(|_, configs| configs.iter().filter(|c| c.name == "other").cloned().collect()));
+    h.mgr.reconfigure().await;
+    eventually(|| h.removed("mock")).await;
+    tokio::time::sleep(Duration::from_millis(1200)).await;
+    assert_eq!(s.launches.load(Ordering::SeqCst), 1, "no restart after the server was dropped");
+}
+
 /// The whole workspace root deleted: the server can never start again
 /// (its cwd is gone), so the crash drops the entry instead of restarting.
 #[tokio::test(flavor = "multi_thread")]
@@ -2807,6 +2957,63 @@ async fn library_classes_in_jars_open_as_their_source_or_decompiled() {
     assert_eq!(asked[0], json!({ "command": "decompile", "arguments": [thing] }));
 }
 
+#[tokio::test(flavor = "multi_thread")]
+async fn library_classes_without_sources_open_decompiled_by_a_running_jdtls() {
+    use std::io::Write;
+    let repo = tempfile::tempdir().unwrap();
+    let jar = dunce::canonicalize(repo.path()).unwrap().join("acme/lib/1.0/lib-1.0.jar");
+    std::fs::create_dir_all(jar.parent().unwrap()).unwrap();
+    let mut zip = zip::ZipWriter::new(std::fs::File::create(&jar).unwrap());
+    zip.start_file("acme/Thing.class", zip::write::SimpleFileOptions::default()).unwrap();
+    zip.write_all(b"\0").unwrap();
+    zip.finish().unwrap();
+    let class = format!("jar://{}!/acme/Thing.class", uri_of(&jar).trim_start_matches("file://"));
+    let escaped = jar.to_string_lossy().replace('/', "%5C/");
+    let jdt = format!("jdt://contents/lib-1.0.jar/acme/Thing.class?=app/{escaped}%3Cacme%28Thing.class");
+    let decompiled =
+        "package acme;\n\npublic class Thing {\n   public void run() {\n      System.out.println();\n   }\n}\n";
+
+    let mut kotlin = incremental_caps();
+    kotlin["executeCommandProvider"] = json!({ "commands": ["decompile"] });
+    let mut java = incremental_caps();
+    java["workspaceSymbolProvider"] = json!(true);
+    let h =
+        harness_languages(&[("kotlin", "kt", &[("kotlin-lsp", kotlin)]), ("java", "java", &[("jdtls", java)])], |_| {});
+    let (doc, _) = h.open("Main.kt", "val thing = Thing()\n");
+    h.wait_status("kotlin-lsp", ServerStatus::Ready).await;
+    let k = h.launcher.state("kotlin-lsp");
+    k.respond(
+        "textDocument/definition",
+        json!({ "uri": class, "range": {"start":{"line":0,"character":6},"end":{"line":0,"character":11}} }),
+    );
+    let r = json!({"start":{"line":2,"character":13},"end":{"line":2,"character":18}});
+
+    // jdtls not running: the Kotlin server's own target and decompiler.
+    let defs = h.mgr.goto(doc, Pos::new(0, 14), GotoKind::Definition).await.unwrap();
+    assert_eq!(defs[0].uri.as_deref(), Some(class.as_str()));
+
+    let path = h.root.join("Sample.java");
+    std::fs::write(&path, "class Sample {}").unwrap();
+    h.mgr.did_open(DocId::next(), &path, &LanguageId::new("java"), 1, "class Sample {}");
+    h.wait_status("jdtls", ServerStatus::Ready).await;
+    let j = h.launcher.state("jdtls");
+    j.respond(
+        "workspace/symbol",
+        json!([{ "name": "Thing", "kind": 5, "containerName": "acme", "location": { "uri": jdt, "range": r } }]),
+    );
+    j.respond("java/classFileContents", json!(decompiled));
+
+    let defs = h.mgr.goto(doc, Pos::new(0, 14), GotoKind::Definition).await.unwrap();
+    assert_eq!(
+        defs,
+        vec![ide_core::Location { path: jdt.clone().into(), range: rng(2, 13, 2, 18), uri: Some(jdt.clone()) }]
+    );
+    assert_eq!(j.requested("workspace/symbol")[0]["query"], "acme.Thing");
+    let vd = h.mgr.virtual_document(&jdt).await.unwrap();
+    assert_eq!(vd.text, decompiled);
+    assert!(k.requested("workspace/executeCommand").is_empty(), "the Kotlin stub is not asked for");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn alternative_java_server_uses_lsp_without_jdt_commands() {
     let h = harness_for("java", "java", &[("kmp-lsp", incremental_caps())], &[]);
@@ -2997,6 +3204,49 @@ async fn fallback_servers_only_run_when_the_preferred_one_is_missing() {
     assert!(h.mgr.hover(doc, Pos::new(0, 0), Default::default()).await.is_ok());
 }
 
+/// A server that is installed but cannot run (crashed for good, or its configuration
+/// can't launch it) hides its fallbacks no longer than one that is missing.
+#[tokio::test(flavor = "multi_thread")]
+async fn fallback_servers_take_over_from_a_preferred_one_that_crashed_for_good() {
+    let h = harness_with_fallbacks(&[("main", incremental_caps()), ("alt", incremental_caps())], &["alt"]);
+    let (doc, path) = h.open("a.mk", "x");
+    let main = h.launcher.state("main");
+    let count = |status| h.statuses("main").iter().filter(|s| **s == status).count();
+    for n in 1..=4 {
+        eventually(|| count(ServerStatus::Ready) == n).await;
+        // Restarting after a crash is not giving up: the fallback stays away.
+        assert!(h.statuses("alt").is_empty(), "alt started after crash {}", n - 1);
+        main.peer().kill();
+        eventually(|| count(ServerStatus::Crashed) == n).await;
+    }
+    h.wait_status("alt", ServerStatus::Ready).await;
+    let uri = uri_of(&path);
+    eventually(|| h.launcher.state("alt").docs.lock().contains_key(&uri)).await;
+    assert!(h.mgr.hover(doc, Pos::new(0, 0), Default::default()).await.is_ok());
+
+    // Restarting the preferred one by hand gives the documents back to it.
+    let id = h.mgr.servers().into_iter().find(|s| s.name == "main").unwrap().id;
+    h.mgr.restart(id).await.unwrap();
+    eventually(|| h.removed("alt")).await;
+    assert_eq!(h.mgr.servers().iter().filter(|s| s.name == "alt").count(), 0);
+}
+
+#[tokio::test(flavor = "multi_thread")]
+async fn fallback_servers_take_over_from_a_preferred_one_that_cannot_be_launched() {
+    let h = harness_with_fallbacks(&[("main", incremental_caps()), ("alt", incremental_caps())], &["alt"]);
+    h.mgr.set_config_hook(Box::new(|cfg, _| {
+        if cfg.name == "main" {
+            cfg.launch_error = Some("needs JDK 21".into());
+        }
+    }));
+    let (doc, path) = h.open("a.mk", "x");
+    h.wait_status("main", ServerStatus::Misconfigured).await;
+    h.wait_status("alt", ServerStatus::Ready).await;
+    let uri = uri_of(&path);
+    eventually(|| h.launcher.state("alt").docs.lock().contains_key(&uri)).await;
+    assert!(h.mgr.hover(doc, Pos::new(0, 0), Default::default()).await.is_ok());
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn a_server_requiring_a_root_marker_serves_only_files_below_one() {
     // `framework` next to `main` (one instance for the whole project), like the

crates/ide-lsp/tests/real_servers.rs

@@ -426,6 +426,7 @@ async fn missing_binary_is_reported_with_install_hint() {
         tsserver_project: false,
         tsserver_project_extras: Default::default(),
         resync_on_configuration: false,
+        display_name: None,
         pinned: None,
     };
     let (mgr, events) = manager(dir.path(), LanguageRegistry::from_configs(vec![lang("nope", "nope", server)]));
@@ -698,6 +699,7 @@ async fn typescript_language_server_end_to_end() {
         tsserver_project: false,
         tsserver_project_extras: Default::default(),
         resync_on_configuration: false,
+        display_name: None,
         pinned: None,
     };
     let (mgr, events) = manager(&root, LanguageRegistry::from_configs(vec![lang("typescript", "ts", server)]));
@@ -750,6 +752,7 @@ fn npm_server(tools: &Path, name: &str, bin: &str, init: Option<serde_json::Valu
         tsserver_project: false,
         tsserver_project_extras: Default::default(),
         resync_on_configuration: false,
+        display_name: None,
         pinned: None,
     }
 }

crates/ide-plugin/src/execution.rs

@@ -61,6 +61,24 @@ pub struct PluginRunConfiguration {
     pub cwd: Option<String>,
     pub test: bool,
     pub framework: Option<String>,
+    /// API 1.9: variables added to the run's environment.
+    #[serde(default)]
+    pub env: Vec<(String, String)>,
+    /// API 1.9: how Debug starts the configuration.
+    #[serde(default)]
+    pub debugger: Option<PluginDebugger>,
+}
+
+/// How Debug starts a plugin configuration (API 1.9 `launch-configurations.debugger`).
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize, Type)]
+#[serde(rename_all = "camelCase", tag = "type")]
+pub enum PluginDebugger {
+    /// `program` under the debugger of this language id.
+    #[serde(rename_all = "camelCase")]
+    Launch { language: String },
+    /// Run, then attach to the first matching process the run starts.
+    #[serde(rename_all = "camelCase")]
+    AttachChild { kind: String, command_contains: Option<String> },
 }
 
 /// RunExited data exchanged with the IDE.

crates/ide-plugin/src/runtime.rs

@@ -36,6 +36,7 @@ use wasmtime::{Config, Engine, Store, StoreLimits, StoreLimitsBuilder, UpdateDea
 use wasmtime_wasi::p2::pipe::MemoryOutputPipe;
 use wasmtime_wasi::{WasiCtx, WasiCtxView, WasiView};
 
+use crate::wit_host::launch_configurations_bindings::exports::openidea::plugin::launch_configurations as wit_launch;
 use crate::wit_host::run_configurations_bindings::exports::openidea::plugin::run_configurations as wit_configs;
 use crate::wit_host::test_results_bindings::exports::openidea::plugin::test_results as wit_tests;
 use bindings::openidea::plugin::events as wit_events;
@@ -55,7 +56,7 @@ use views_bindings::exports::openidea::plugin::view_provider as wit_view;
 use views_bindings::openidea::plugin::view_types as wit_vt;
 
 /// The API version of the world above, `major.minor` of [`host_api`].
-pub const API_VERSION: &str = "1.8";
+pub const API_VERSION: &str = "1.9";
 const EPOCH_TICK: Duration = Duration::from_millis(10);
 pub(crate) const MAX_TEXT: usize = 1 << 20;
 pub(crate) const MAX_TITLE: usize = 256;
@@ -1008,6 +1009,7 @@ struct Exports {
     inlay: Option<wit_inlay::Guest>,
     endpoints: Option<wit_endpoints::Guest>,
     run_configurations: Option<wit_configs::Guest>,
+    launch_configurations: Option<wit_launch::Guest>,
     test_results: Option<wit_tests::Guest>,
     mcp: Option<crate::wit_host::mcp_bindings::exports::openidea::plugin::mcp_provider::Guest>,
 }
@@ -1147,6 +1149,7 @@ impl Runtime {
         let inlay_indices = wit_inlay::GuestIndices::new(&pre).ok();
         let endpoint_indices = wit_endpoints::GuestIndices::new(&pre).ok();
         let configs_indices = wit_configs::GuestIndices::new(&pre).ok();
+        let launch_indices = wit_launch::GuestIndices::new(&pre).ok();
         let tests_indices = wit_tests::GuestIndices::new(&pre).ok();
         let validation_indices = wit_rtv::GuestIndices::new(&pre).ok();
         let lf_indices = wit_lf::GuestIndices::new(&pre).ok();
@@ -1157,6 +1160,8 @@ impl Runtime {
         let mcp = mcp_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let run_configurations =
             configs_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
+        let launch_configurations =
+            launch_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let test_results = tests_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let language_features = lf_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
         let injections = inj_indices.map(|i| i.load(&mut store, &instance)).transpose().map_err(api_hint)?;
@@ -1230,6 +1235,7 @@ impl Runtime {
                 inlay,
                 endpoints,
                 run_configurations,
+                launch_configurations,
                 test_results,
                 mcp,
                 file_actions,
@@ -1269,34 +1275,67 @@ impl Runtime {
         .map(|r| r.map_err(|message| clip(message, 4096)))
     }
 
-    /// Complete configurations from the optional API 1.4 export.
+    /// Complete configurations from the optional API 1.9 export, else the API 1.4 one.
     pub fn run_configurations(
         &mut self,
         root: String,
         timeout: Duration,
     ) -> Result<Vec<crate::PluginRunConfiguration>, CallError> {
-        if self.exports.run_configurations.is_none() {
-            return Err(CallError::missing_export("run-configurations"));
-        }
         let invocation = Invocation { workspace_root: Some(root.clone().into()), ..Default::default() };
-        let items = self.call(invocation, timeout, |e, store| {
-            e.run_configurations.as_ref().unwrap().call_configurations(store, &root)
-        })?;
-        if items.len() > 1000 {
-            return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
-        }
-        Ok(items
-            .into_iter()
-            .map(|c| crate::PluginRunConfiguration {
-                id: c.id,
-                name: c.name,
-                program: c.program,
-                args: c.args,
-                cwd: c.cwd,
-                test: c.test,
-                framework: c.framework,
-            })
-            .collect())
+        let items: Vec<crate::PluginRunConfiguration> = if self.exports.launch_configurations.is_some() {
+            let items = self.call(invocation, timeout, |e, store| {
+                e.launch_configurations.as_ref().unwrap().call_configurations(store, &root)
+            })?;
+            if items.len() > 1000 {
+                return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
+            }
+            items
+                .into_iter()
+                .map(|c| crate::PluginRunConfiguration {
+                    id: c.id,
+                    name: c.name,
+                    program: c.program,
+                    args: c.args,
+                    cwd: c.cwd,
+                    test: c.test,
+                    framework: c.framework,
+                    env: c.env,
+                    debugger: match c.debugger {
+                        Some(wit_launch::Debugger::Launch(language)) => {
+                            Some(crate::PluginDebugger::Launch { language })
+                        }
+                        Some(wit_launch::Debugger::AttachChild(a)) => Some(crate::PluginDebugger::AttachChild {
+                            kind: a.kind,
+                            command_contains: a.command_contains,
+                        }),
+                        Some(wit_launch::Debugger::Other(_)) | None => None,
+                    },
+                })
+                .collect()
+        } else if self.exports.run_configurations.is_some() {
+            let items = self.call(invocation, timeout, |e, store| {
+                e.run_configurations.as_ref().unwrap().call_configurations(store, &root)
+            })?;
+            if items.len() > 1000 {
+                return Err(CallError::Guest(GuestError::Invalid("too many run configurations".into())));
+            }
+            items
+                .into_iter()
+                .map(|c| crate::PluginRunConfiguration {
+                    id: c.id,
+                    name: c.name,
+                    program: c.program,
+                    args: c.args,
+                    cwd: c.cwd,
+                    test: c.test,
+                    framework: c.framework,
+                    ..Default::default()
+                })
+                .collect()
+        } else {
+            return Err(CallError::missing_export("run-configurations"));
+        };
+        Ok(items)
     }
     /// Selects tests under the same budget as the test parser.
     pub fn select_tests(

crates/ide-plugin/src/wit_host.rs

@@ -2254,6 +2254,11 @@ impl bindings::openidea::plugin::run::Host for StoreData {
 pub(crate) mod run_configurations_bindings {
     wasmtime::component::bindgen!({ world: "configurations-provider", path: "../../wit" });
 }
+pub(crate) mod launch_configurations_bindings {
+    wasmtime::component::bindgen!({ world: "launch-configurations-provider", path: "../../wit",
+        with: { "openidea:plugin/types": super::bindings::openidea::plugin::types },
+    });
+}
 pub(crate) mod test_results_bindings {
     wasmtime::component::bindgen!({ world: "test-results-provider", path: "../../wit",
         with: { "openidea:plugin/types": super::bindings::openidea::plugin::types },

crates/ide-plugin/tests/api_compat.rs

@@ -91,15 +91,15 @@ fn the_sdk_carries_the_hosts_wit() {
 
 #[test]
 fn the_version_check_runs_compatible_components_and_explains_the_rest() {
-    let host = v("1.8.0");
-    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.8.0", "1.0.0-rc.1"] {
+    let host = v("1.9.0");
+    for ok in ["1.0.0", "1.3.0", "1.4.7", "1.5.0", "1.6.0", "1.7.0", "1.8.0", "1.9.0", "1.0.0-rc.1"] {
         assert_eq!(check_api(&v(ok), &host), Ok(()), "{ok}");
     }
-    let newer = check_api(&v("1.9.0"), &host).unwrap_err();
-    assert!(newer.contains("1.9") && newer.contains("update OpenIDEA"), "{newer}");
+    let newer = check_api(&v("1.10.0"), &host).unwrap_err();
+    assert!(newer.contains("1.10") && newer.contains("update OpenIDEA"), "{newer}");
     assert!(check_api(&v("2.0.0"), &host).unwrap_err().contains("update OpenIDEA"));
     let older = check_api(&v("0.2.0"), &host).unwrap_err();
-    assert!(older.contains("rebuild it with the 1.8 SDK"), "{older}");
+    assert!(older.contains("rebuild it with the 1.9 SDK"), "{older}");
     // 0.x: every minor is its own API.
     assert_eq!(check_api(&v("0.2.0"), &v("0.2.5")), Ok(()));
     assert!(check_api(&v("0.1.0"), &v("0.2.0")).is_err());

crates/ide-plugin/tests/fixtures/api14/dist/plugin.wasm.sources

@@ -1 +1 @@
-e616b87b24371581ad648f9c7072259de7732d122b5887b488f7bd480ebd69c2
+a3d2511f30277245a8cb9673c4d8a948a8a025b8b9149d5015bed5137a98ccdd

crates/ide-plugin/tests/fixtures/commit/dist/plugin.wasm.sources

@@ -1 +1 @@
-75eeecc467bff141bda14f1f080633348af348f7259e793be81e6548d2008669
+dad3edad99ad85234aa612bbc1f3a66e50361189e54038b91674703815f049cc

crates/ide-plugin/tests/fixtures/data-tools/dist/plugin.wasm.sources

@@ -1 +1 @@
-4aaf7754e895f022d34dad05bd2b8018e3a61ba18771b8c95d9f070cb212530c
+918af7d4d8bc302621b9b68070a56930813b1fc2ba235d89de4e56c53eaba5bd

crates/ide-plugin/tests/fixtures/detail-views/dist/plugin.wasm.sources

@@ -1 +1 @@
-e573144879a7caa0975e17b233476eb317ff54bef23fd8fa64280d3649bad700
+7a140c2255a3d251a5ab9079bec953cccc4408727b067b49da47cf8fb27d8cb8

crates/ide-plugin/tests/fixtures/diagnostics/dist/plugin.wasm.sources

@@ -1 +1 @@
-36dd40ef751a617f1ad59491312889c12481b05666e580f21f7c2552df76edbc
+ef41934bd0b67f76a17ef321b44c172496314c9fea6b46b4cd2f1d0f4b96907d

crates/ide-plugin/tests/fixtures/endpoints/dist/plugin.wasm.sources

@@ -1 +1 @@
-724ed3bbd828e4fc1925c1b555bdaec9268633cb587806a661f8838e5a540545
+c6dc1ae00d9f3d936f4bf5ff110915050cb503ac06982bdc48e967deac84a913

crates/ide-plugin/tests/fixtures/execution/dist/plugin.wasm.sources

@@ -1 +1 @@
-1a3685234f1b3b0957184c44c603c0eefe7e3084b88d0df32da268b29292ee92
+25a782556dd6bbf8ed1ad7b50b9b55685f074d80220af08f3bd9cb12cf07f74e

crates/ide-plugin/tests/fixtures/execution/plugin.toml

@@ -1,7 +1,7 @@
 id = "execution"
 name = "Plugin execution tests"
 version = "0.1.0"
-engines.openidea = "^1.5"
+engines.openidea = "^1.9"
 wasm = "dist/plugin.wasm"
 activation = ["on-command:*"]
 [capabilities]

crates/ide-plugin/tests/fixtures/execution/src/lib.rs

@@ -114,17 +114,37 @@ impl Plugin for Execution {
         host::storage::set("events", &serde_json::to_string(&received).unwrap()).unwrap();
     }
 }
-impl RunConfigurations for Execution {
-    fn configurations(&mut self, _: &str) -> Vec<PluginRunConfiguration> {
-        vec![PluginRunConfiguration {
-            id: "dynamic".into(),
-            name: "Dynamic tests".into(),
-            program: "execution-tool".into(),
-            args: vec!["test".into()],
-            test: true,
-            framework: Some("plugin".into()),
-            ..Default::default()
-        }]
+impl LaunchConfigurations for Execution {
+    fn launch_configurations(&mut self, _: &str) -> Vec<PluginLaunchConfiguration> {
+        vec![
+            PluginLaunchConfiguration {
+                config: PluginRunConfiguration {
+                    id: "dynamic".into(),
+                    name: "Dynamic tests".into(),
+                    program: "execution-tool".into(),
+                    args: vec!["test".into()],
+                    test: true,
+                    framework: Some("plugin".into()),
+                    ..Default::default()
+                },
+                env: vec![("OPENIDEA_EXECUTION_FIXTURE".into(), "1".into())],
+                debugger: Some(Debugger::Launch { language: "python".into() }),
+            },
+            PluginLaunchConfiguration {
+                config: PluginRunConfiguration {
+                    id: "worker".into(),
+                    name: "Worker".into(),
+                    program: "execution-tool".into(),
+                    args: vec!["start".into()],
+                    ..Default::default()
+                },
+                env: Vec::new(),
+                debugger: Some(Debugger::AttachChild {
+                    kind: "dotnet".into(),
+                    command_contains: Some("Worker.dll".into()),
+                }),
+            },
+        ]
     }
 }
 impl TestResults for Execution {
@@ -181,4 +201,4 @@ impl RunTargetValidation for Execution {
         }
     }
 }
-register_plugin!(Execution, run_configurations, test_results, run_target_validation);
+register_plugin!(Execution, launch_configurations, test_results, run_target_validation);

crates/ide-plugin/tests/fixtures/ext-owner/dist/plugin.wasm.sources

@@ -1 +1 @@
-4283de821d69a18438f58062e4bc28b63ba5025cc5f9fa51f21ff475b677a6a5
+f58b5f68d56611c3d15f69ff8e73e6e65d84e55d14c9bae00ed50b346460adfa