Fix stale Claude sidebar status: add missing hooks, OSC suppression, PID sweep (#1306)

* Fix stale Claude status in sidebar by adding missing hooks and OSC suppression

The Claude Code integration only used 3 hooks (SessionStart, Stop, Notification),
leaving gaps that caused stale sidebar status. Now uses 6 hooks:

- SessionEnd: clears status when Claude exits (covers Ctrl+C where Stop doesn't fire)
- UserPromptSubmit: clears "Needs input" and sets "Running" on new prompt
- PreToolUse (async): clears "Needs input" when Claude resumes after permission grant

Also:
- Suppress OSC 9/99 desktop notifications for workspaces with active Claude hook
  sessions to prevent duplicates from the raw OSC path
- Store Claude process PID in status entries for stale-session detection
- Add 30-second sweep timer that checks agent PIDs and clears stale entries
  (safety net for SIGKILL/crash where no hook fires)
- Update wrapper test expectations for the new hook set

Fixes https://github.com/manaflow-ai/cmux/issues/1301

* Don't show "Running" status on Claude launch, only when actually working

SessionStart now registers the PID for tracking and OSC suppression via
set_agent_pid without setting a visible status entry. "Running" only
appears when the user submits a prompt (UserPromptSubmit) or Claude
starts using tools (PreToolUse).

Added set_agent_pid / clear_agent_pid socket commands to decouple PID
tracking from visible status entries. OSC suppression checks agentPIDs
instead of statusEntries so it works during the initial idle period.

* Don't restore status entries across app restarts

Status entries are ephemeral runtime state tied to running processes
(e.g. claude_code "Running"). Restoring them after restart shows stale
status for processes that no longer exist.

* Address PR review comments and remove debug logging

- session-end: only clear status/PID/notifications when Stop didn't fire first
- PID sweep: check errno == ESRCH instead of treating all kill(pid,0) failures as dead
- Validate CMUX_CLAUDE_PID > 0
- Propagate tracked PID in pre-tool-use setClaudeStatus
- OSC suppression: use tabManagerFor(tabId:) for multi-window support
- clearAgentPID: resolve tab UUID before async dispatch
- restoreSessionSnapshot: also clear agentPIDs alongside statusEntries
- Fix AskUserQuestion surfaceId overwrite (wrong workspace notification)
- Fix notification text matching for "Claude Code needs your attention"
- AskUserQuestion: render option labels as bracketed inline text
- Remove artificial text truncation limits
- Remove temporary JSONL debug logging from all handlers

* Use resolveTabIdForSidebarMutation in clearAgentPID

CLI/cmux.swift

@@ -316,6 +316,7 @@ private struct ClaudeHookSessionRecord: Codable {
     var workspaceId: String
     var surfaceId: String
     var cwd: String?
+    var pid: Int?
     var lastSubtitle: String?
     var lastBody: String?
     var startedAt: TimeInterval
@@ -363,6 +364,7 @@ private final class ClaudeHookSessionStore {
         workspaceId: String,
         surfaceId: String,
         cwd: String?,
+        pid: Int? = nil,
         lastSubtitle: String? = nil,
         lastBody: String? = nil
     ) throws {
@@ -375,16 +377,22 @@ private final class ClaudeHookSessionStore {
                 workspaceId: workspaceId,
                 surfaceId: surfaceId,
                 cwd: nil,
+                pid: nil,
                 lastSubtitle: nil,
                 lastBody: nil,
                 startedAt: now,
                 updatedAt: now
             )
             record.workspaceId = workspaceId
+            if !surfaceId.isEmpty {
                 record.surfaceId = surfaceId
+            }
             if let cwd = normalizeOptional(cwd) {
                 record.cwd = cwd
             }
+            if let pid {
+                record.pid = pid
+            }
             if let subtitle = normalizeOptional(lastSubtitle) {
                 record.lastSubtitle = subtitle
             }
@@ -8477,39 +8485,68 @@ struct CMUXCLI {
                 workspaceId: workspaceId,
                 client: client
             )
+            let claudePid: Int? = {
+                guard let raw = ProcessInfo.processInfo.environment["CMUX_CLAUDE_PID"]?
+                    .trimmingCharacters(in: .whitespacesAndNewlines),
+                    let pid = Int(raw),
+                    pid > 0 else {
+                    return nil
+                }
+                return pid
+            }()
             if let sessionId = parsedInput.sessionId {
                 try? sessionStore.upsert(
                     sessionId: sessionId,
                     workspaceId: workspaceId,
                     surfaceId: surfaceId,
-                    cwd: parsedInput.cwd
+                    cwd: parsedInput.cwd,
+                    pid: claudePid
                 )
             }
-            try setClaudeStatus(
+            // Register PID for stale-session detection and OSC suppression,
-                client: client,
+            // but don't set a visible status. "Running" only appears when the
-                workspaceId: workspaceId,
+            // user submits a prompt (UserPromptSubmit) or Claude starts working
-                value: "Running",
+            // (PreToolUse).
-                icon: "bolt.fill",
+            if let claudePid {
-                color: "#4C8DFF"
+                _ = try? sendV1Command(
+                    "set_agent_pid claude_code \(claudePid) --tab=\(workspaceId)",
+                    client: client
                 )
+            }
             print("OK")
 
         case "stop", "idle":
             telemetry.breadcrumb("claude-hook.stop")
-            let consumedSession = try? sessionStore.consume(
+            // Turn ended. Don't consume session or clear PID — Claude is still alive.
-                sessionId: parsedInput.sessionId,
+            // Notification hook handles user-facing notifications; SessionEnd handles cleanup.
-                workspaceId: fallbackWorkspaceId,
+            var workspaceId = fallbackWorkspaceId
-                surfaceId: fallbackSurfaceId
+            var surfaceId = surfaceArg
-            )
+            if let sessionId = parsedInput.sessionId,
-            let workspaceId = consumedSession?.workspaceId ?? fallbackWorkspaceId
+               let mapped = try? sessionStore.lookup(sessionId: sessionId),
-            try clearClaudeStatus(client: client, workspaceId: workspaceId)
+               let mappedWorkspace = try? resolveWorkspaceIdForClaudeHook(mapped.workspaceId, client: client) {
+                workspaceId = mappedWorkspace
+                surfaceId = mapped.surfaceId
+            }
 
-            if let completion = summarizeClaudeHookStop(
+            // Update session with transcript summary and send completion notification.
+            let completion = summarizeClaudeHookStop(
                 parsedInput: parsedInput,
-                sessionRecord: consumedSession
+                sessionRecord: (try? sessionStore.lookup(sessionId: parsedInput.sessionId ?? ""))
-            ) {
+            )
-                let surfaceId = try resolveSurfaceIdForClaudeHook(
+            if let sessionId = parsedInput.sessionId, let completion {
-                    consumedSession?.surfaceId ?? surfaceArg,
+                try? sessionStore.upsert(
+                    sessionId: sessionId,
+                    workspaceId: workspaceId,
+                    surfaceId: surfaceId ?? "",
+                    cwd: parsedInput.cwd,
+                    lastSubtitle: completion.subtitle,
+                    lastBody: completion.body
+                )
+            }
+
+            if let completion {
+                let resolvedSurface = try resolveSurfaceIdForClaudeHook(
+                    surfaceId,
                     workspaceId: workspaceId,
                     client: client
                 )
@@ -8517,12 +8554,18 @@ struct CMUXCLI {
                 let subtitle = sanitizeNotificationField(completion.subtitle)
                 let body = sanitizeNotificationField(completion.body)
                 let payload = "\(title)|\(subtitle)|\(body)"
-                let response = try sendV1Command("notify_target \(workspaceId) \(surfaceId) \(payload)", client: client)
+                _ = try? sendV1Command("notify_target \(workspaceId) \(resolvedSurface) \(payload)", client: client)
-                print(response)
-            } else {
-                print("OK")
             }
 
+            try setClaudeStatus(
+                client: client,
+                workspaceId: workspaceId,
+                value: "Idle",
+                icon: "pause.circle.fill",
+                color: "#8E8E93"
+            )
+            print("OK")
+
         case "prompt-submit":
             telemetry.breadcrumb("claude-hook.prompt-submit")
             var workspaceId = fallbackWorkspaceId
@@ -8543,7 +8586,7 @@ struct CMUXCLI {
 
         case "notification", "notify":
             telemetry.breadcrumb("claude-hook.notification")
-            let summary = summarizeClaudeHookNotification(rawInput: rawInput)
+            var summary = summarizeClaudeHookNotification(rawInput: rawInput)
 
             var workspaceId = fallbackWorkspaceId
             var preferredSurface = surfaceArg
@@ -8552,6 +8595,12 @@ struct CMUXCLI {
                let mappedWorkspace = try? resolveWorkspaceIdForClaudeHook(mapped.workspaceId, client: client) {
                 workspaceId = mappedWorkspace
                 preferredSurface = mapped.surfaceId
+                // If PreToolUse saved a richer message (e.g. from AskUserQuestion),
+                // use it instead of the generic notification text.
+                if let savedBody = mapped.lastBody, !savedBody.isEmpty,
+                   summary.body.contains("needs your attention") || summary.body.contains("needs your input") {
+                    summary = (subtitle: mapped.lastSubtitle ?? summary.subtitle, body: savedBody)
+                }
             }
 
             let surfaceId = try resolveSurfaceIdForClaudeHook(
@@ -8586,11 +8635,86 @@ struct CMUXCLI {
             )
             print(response)
 
+        case "session-end":
+            telemetry.breadcrumb("claude-hook.session-end")
+            // Final cleanup when Claude process exits.
+            // Only clear when we are the primary cleanup path (Stop didn't fire first).
+            // If Stop already consumed the session, consumedSession is nil and we skip
+            // to avoid wiping the completion notification that Stop just delivered.
+            let consumedSession = try? sessionStore.consume(
+                sessionId: parsedInput.sessionId,
+                workspaceId: fallbackWorkspaceId,
+                surfaceId: fallbackSurfaceId
+            )
+            if let consumedSession {
+                let workspaceId = consumedSession.workspaceId
+                _ = try? clearClaudeStatus(client: client, workspaceId: workspaceId)
+                _ = try? sendV1Command("clear_agent_pid claude_code --tab=\(workspaceId)", client: client)
+                _ = try? sendV1Command("clear_notifications --tab=\(workspaceId)", client: client)
+            }
+            print("OK")
+
+        case "pre-tool-use":
+            telemetry.breadcrumb("claude-hook.pre-tool-use")
+            // Clears "Needs input" status and notification when Claude resumes work
+            // (e.g. after permission grant). Runs async so it doesn't block tool execution.
+            var workspaceId = fallbackWorkspaceId
+            var claudePid: Int? = nil
+            if let sessionId = parsedInput.sessionId,
+               let mapped = try? sessionStore.lookup(sessionId: sessionId),
+               let mappedWorkspace = try? resolveWorkspaceIdForClaudeHook(mapped.workspaceId, client: client) {
+                workspaceId = mappedWorkspace
+                claudePid = mapped.pid
+            }
+
+            // AskUserQuestion means Claude is about to ask the user something.
+            // Save question text in session so the Notification handler can use it
+            // instead of the generic "Claude Code needs your attention".
+            if let toolName = parsedInput.object?["tool_name"] as? String,
+               toolName == "AskUserQuestion",
+               let question = describeAskUserQuestion(parsedInput.object),
+               let sessionId = parsedInput.sessionId {
+                // Preserve the existing surfaceId from SessionStart; passing ""
+                // would overwrite it and cause notifications to target the wrong workspace.
+                let existingSurfaceId = (try? sessionStore.lookup(sessionId: sessionId))?.surfaceId ?? ""
+                try? sessionStore.upsert(
+                    sessionId: sessionId,
+                    workspaceId: workspaceId,
+                    surfaceId: existingSurfaceId,
+                    cwd: parsedInput.cwd,
+                    lastSubtitle: "Waiting",
+                    lastBody: question
+                )
+                // Don't clear notifications or set status here.
+                // The Notification hook fires right after and will use the saved question.
+                print("OK")
+                return
+            }
+
+            _ = try? sendV1Command("clear_notifications --tab=\(workspaceId)", client: client)
+
+            let statusValue: String
+            if UserDefaults.standard.bool(forKey: "claudeCodeVerboseStatus"),
+               let toolStatus = describeToolUse(parsedInput.object) {
+                statusValue = toolStatus
+            } else {
+                statusValue = "Running"
+            }
+            try setClaudeStatus(
+                client: client,
+                workspaceId: workspaceId,
+                value: statusValue,
+                icon: "bolt.fill",
+                color: "#4C8DFF",
+                pid: claudePid
+            )
+            print("OK")
+
         case "help", "--help", "-h":
             telemetry.breadcrumb("claude-hook.help")
             print(
                 """
-                cmux claude-hook <session-start|stop|notification> [--workspace <id|index>] [--surface <id|index>]
+                cmux claude-hook <session-start|stop|session-end|notification|prompt-submit|pre-tool-use> [--workspace <id|index>] [--surface <id|index>]
                 """
             )
 
@@ -8604,17 +8728,105 @@ struct CMUXCLI {
         workspaceId: String,
         value: String,
         icon: String,
-        color: String
+        color: String,
+        pid: Int? = nil
     ) throws {
-        _ = try client.send(
+        var cmd = "set_status claude_code \(value) --icon=\(icon) --color=\(color) --tab=\(workspaceId)"
-            command: "set_status claude_code \(value) --icon=\(icon) --color=\(color) --tab=\(workspaceId)"
+        if let pid {
-        )
+            cmd += " --pid=\(pid)"
+        }
+        _ = try client.send(command: cmd)
     }
 
     private func clearClaudeStatus(client: SocketClient, workspaceId: String) throws {
         _ = try client.send(command: "clear_status claude_code --tab=\(workspaceId)")
     }
 
+    private func describeAskUserQuestion(_ object: [String: Any]?) -> String? {
+        guard let object,
+              let input = object["tool_input"] as? [String: Any],
+              let questions = input["questions"] as? [[String: Any]],
+              let first = questions.first else { return nil }
+
+        var parts: [String] = []
+
+        if let question = first["question"] as? String, !question.isEmpty {
+            parts.append(question)
+        } else if let header = first["header"] as? String, !header.isEmpty {
+            parts.append(header)
+        }
+
+        if let options = first["options"] as? [[String: Any]] {
+            let labels = options.compactMap { $0["label"] as? String }
+            if !labels.isEmpty {
+                parts.append(labels.map { "[\($0)]" }.joined(separator: " "))
+            }
+        }
+
+        if parts.isEmpty { return "Asking a question" }
+        return parts.joined(separator: "\n")
+    }
+
+    private func describeToolUse(_ object: [String: Any]?) -> String? {
+        guard let object, let toolName = object["tool_name"] as? String else { return nil }
+        let input = object["tool_input"] as? [String: Any]
+
+        switch toolName {
+        case "Read":
+            if let path = input?["file_path"] as? String {
+                return "Reading \(shortenPath(path))"
+            }
+            return "Reading file"
+        case "Edit":
+            if let path = input?["file_path"] as? String {
+                return "Editing \(shortenPath(path))"
+            }
+            return "Editing file"
+        case "Write":
+            if let path = input?["file_path"] as? String {
+                return "Writing \(shortenPath(path))"
+            }
+            return "Writing file"
+        case "Bash":
+            if let cmd = input?["command"] as? String {
+                let first = cmd.components(separatedBy: .whitespacesAndNewlines).first ?? cmd
+                let short = String(first.prefix(30))
+                return "Running \(short)"
+            }
+            return "Running command"
+        case "Glob":
+            if let pattern = input?["pattern"] as? String {
+                return "Searching \(String(pattern.prefix(30)))"
+            }
+            return "Searching files"
+        case "Grep":
+            if let pattern = input?["pattern"] as? String {
+                return "Grep \(String(pattern.prefix(30)))"
+            }
+            return "Searching code"
+        case "Agent":
+            if let desc = input?["description"] as? String {
+                return String(desc.prefix(40))
+            }
+            return "Subagent"
+        case "WebFetch":
+            return "Fetching URL"
+        case "WebSearch":
+            if let query = input?["query"] as? String {
+                return "Search: \(String(query.prefix(30)))"
+            }
+            return "Web search"
+        default:
+            return toolName
+        }
+    }
+
+    private func shortenPath(_ path: String) -> String {
+        let url = URL(fileURLWithPath: path)
+        let name = url.lastPathComponent
+        return name.isEmpty ? String(path.suffix(30)) : name
+    }
+
     private func resolveWorkspaceIdForClaudeHook(_ raw: String?, client: SocketClient) throws -> String {
         if let raw, !raw.isEmpty, let candidate = try? resolveWorkspaceId(raw, client: client) {
             let probe = try? client.sendV2(method: "surface.list", params: ["workspace_id": candidate])
@@ -8816,20 +9028,13 @@ struct CMUXCLI {
         let signal = signalParts.compactMap { $0 }.joined(separator: " ")
         var classified = classifyClaudeNotification(signal: signal, message: normalizedMessage)
 
-        if let session, !session.isEmpty {
-            let shortSession = String(session.prefix(8))
-            if !classified.body.contains(shortSession) {
-                classified.body = "\(classified.body) [\(shortSession)]"
-            }
-        }
-
         classified.body = truncate(classified.body, maxLength: 180)
         return classified
     }
 
     private func classifyClaudeNotification(signal: String, message: String) -> (subtitle: String, body: String) {
         let lower = "\(signal) \(message)".lowercased()
-        if lower.contains("permission") || lower.contains("approve") || lower.contains("approval") {
+        if lower.contains("permission") || lower.contains("approve") || lower.contains("approval") || lower.contains("permission_prompt") {
             let body = message.isEmpty ? "Approval needed" : message
             return ("Permission", body)
         }
@@ -8837,12 +9042,19 @@ struct CMUXCLI {
             let body = message.isEmpty ? "Claude reported an error" : message
             return ("Error", body)
         }
-        if lower.contains("idle") || lower.contains("wait") || lower.contains("input") || lower.contains("prompt") {
+        if lower.contains("complet") || lower.contains("finish") || lower.contains("done") || lower.contains("success") {
-            let body = message.isEmpty ? "Claude is waiting for your input" : message
+            let body = message.isEmpty ? "Task completed" : message
+            return ("Completed", body)
+        }
+        if lower.contains("idle") || lower.contains("wait") || lower.contains("input") || lower.contains("idle_prompt") {
+            let body = message.isEmpty ? "Waiting for input" : message
             return ("Waiting", body)
         }
-        let body = message.isEmpty ? "Claude needs your input" : message
+        // Use the message directly if it's meaningful (not a generic placeholder).
-        return ("Attention", body)
+        if !message.isEmpty, message != "Claude needs your input" {
+            return ("Attention", message)
+        }
+        return ("Attention", "Claude needs your attention")
     }
 
     private func dedupeBranchContextLines(_ value: String) -> String {
@@ -8906,9 +9118,8 @@ struct CMUXCLI {
     }
 
     private func sanitizeNotificationField(_ value: String) -> String {
-        let normalized = normalizedSingleLine(value)
+        return normalizedSingleLine(value)
             .replacingOccurrences(of: "|", with: "¦")
-        return truncate(normalized, maxLength: 180)
     }
 
     private func versionSummary() -> String {

Resources/bin/claude

@@ -76,9 +76,17 @@ for arg in "$@"; do
     esac
 done
 
+# Export the wrapper's PID. Because we exec claude below, this PID becomes
+# the actual claude process PID, which hooks use for stale-session detection.
+export CMUX_CLAUDE_PID=$$
+
 # Build hooks settings JSON.
 # Claude Code merges --settings additively with the user's own settings.json.
-HOOKS_JSON='{"hooks":{"SessionStart":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook session-start","timeout":10}]}],"Stop":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook stop","timeout":10}]}],"Notification":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook notification","timeout":10}]}]}}'
+# - SessionStart/Stop/Notification: existing lifecycle hooks
+# - SessionEnd: cleanup when Claude exits (covers Ctrl+C where Stop doesn't fire)
+# - UserPromptSubmit: clears "Needs input" and sets "Running" on new prompt
+# - PreToolUse: clears "Needs input" when Claude resumes after permission grant (async to avoid latency)
+HOOKS_JSON='{"hooks":{"SessionStart":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook session-start","timeout":10}]}],"Stop":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook stop","timeout":10}]}],"SessionEnd":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook session-end","timeout":1}]}],"Notification":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook notification","timeout":10}]}],"UserPromptSubmit":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook prompt-submit","timeout":10}]}],"PreToolUse":[{"matcher":"","hooks":[{"type":"command","command":"cmux claude-hook pre-tool-use","timeout":5,"async":true}]}]}}'
 
 if [[ "$SKIP_SESSION_ID" == true ]]; then
     exec "$REAL_CLAUDE" --settings "$HOOKS_JSON" "$@"

Sources/GhosttyTerminalView.swift

@@ -1923,7 +1923,15 @@ class GhosttyApp {
                           let tabId = tabManager.selectedTabId else {
                         return false
                     }
-                    let tabTitle = tabManager.titleForTab(tabId) ?? "Terminal"
+                    // Suppress OSC notifications for workspaces with active Claude hook sessions.
+                    // The hook system manages notifications with proper lifecycle tracking;
+                    // raw OSC notifications would duplicate or outlive the structured hooks.
+                    let owningManager = AppDelegate.shared?.tabManagerFor(tabId: tabId) ?? tabManager
+                    if let workspace = owningManager.tabs.first(where: { $0.id == tabId }),
+                       workspace.agentPIDs["claude_code"] != nil {
+                        return true
+                    }
+                    let tabTitle = owningManager.titleForTab(tabId) ?? "Terminal"
                     let command = actionTitle.isEmpty ? tabTitle : actionTitle
                     let body = actionBody
                     let surfaceId = tabManager.focusedSurfaceId(for: tabId)
@@ -2195,7 +2203,13 @@ class GhosttyApp {
             let actionBody = action.action.desktop_notification.body
                 .flatMap { String(cString: $0) } ?? ""
             performOnMain {
-                let tabTitle = AppDelegate.shared?.tabManager?.titleForTab(tabId) ?? "Terminal"
+                // Suppress OSC notifications for workspaces with active Claude hook sessions.
+                let owningManager = AppDelegate.shared?.tabManagerFor(tabId: tabId) ?? AppDelegate.shared?.tabManager
+                if let workspace = owningManager?.tabs.first(where: { $0.id == tabId }),
+                   workspace.agentPIDs["claude_code"] != nil {
+                    return
+                }
+                let tabTitle = owningManager?.titleForTab(tabId) ?? "Terminal"
                 let command = actionTitle.isEmpty ? tabTitle : actionTitle
                 let body = actionBody
                 TerminalNotificationStore.shared.addNotification(

Sources/TabManager.swift

@@ -751,6 +751,7 @@ class TabManager: ObservableObject {
             return tabs.first(where: { $0.id == selectedTabId })
         }
     }
+    private var agentPIDSweepTimer: DispatchSourceTimer?
 #if DEBUG
     private var debugWorkspaceSwitchCounter: UInt64 = 0
     private var debugWorkspaceSwitchId: UInt64 = 0
@@ -796,6 +797,8 @@ class TabManager: ObservableObject {
             }
         })
 
+        startAgentPIDSweepTimer()
+
 #if DEBUG
         setupUITestFocusShortcutsIfNeeded()
         setupSplitCloseRightUITestIfNeeded()
@@ -806,6 +809,54 @@ class TabManager: ObservableObject {
 
     deinit {
         workspaceCycleCooldownTask?.cancel()
+        agentPIDSweepTimer?.cancel()
+    }
+
+    // MARK: - Agent PID Sweep
+
+    /// Periodically checks agent PIDs associated with status entries.
+    /// If a process has exited (SIGKILL, crash, etc.), clears the stale status entry.
+    /// This is the safety net for cases where no hook fires (e.g. SIGKILL).
+    private func startAgentPIDSweepTimer() {
+        let timer = DispatchSource.makeTimerSource(queue: .global(qos: .utility))
+        timer.schedule(deadline: .now() + 30, repeating: 30)
+        timer.setEventHandler { [weak self] in
+            guard let self else { return }
+            DispatchQueue.main.async { [weak self] in
+                guard let self else { return }
+                self.sweepStaleAgentPIDs()
+            }
+        }
+        timer.resume()
+        agentPIDSweepTimer = timer
+    }
+
+    private func sweepStaleAgentPIDs() {
+        for tab in tabs {
+            var keysToRemove: [String] = []
+            for (key, pid) in tab.agentPIDs {
+                guard pid > 0 else {
+                    keysToRemove.append(key)
+                    continue
+                }
+                // kill(pid, 0) probes process liveness without sending a signal.
+                // ESRCH = process doesn't exist (stale). EPERM = process exists
+                // but we lack permission (not stale, keep tracking).
+                errno = 0
+                if kill(pid, 0) == -1, POSIXErrorCode(rawValue: errno) == .ESRCH {
+                    keysToRemove.append(key)
+                }
+            }
+            if !keysToRemove.isEmpty {
+                for key in keysToRemove {
+                    tab.statusEntries.removeValue(forKey: key)
+                    tab.agentPIDs.removeValue(forKey: key)
+                }
+                // Also clear stale notifications (e.g. "Doing well, thanks!")
+                // left behind when Claude was killed without SessionEnd firing.
+                AppDelegate.shared?.notificationStore?.clearNotifications(forTabId: tab.id)
+            }
+        }
     }
 
     private func wireClosedBrowserTracking(for workspace: Workspace) {

Sources/TerminalController.swift

@@ -1562,6 +1562,12 @@ class TerminalController {
         case "clear_status":
             return clearStatus(args)
 
+        case "set_agent_pid":
+            return setAgentPID(args)
+
+        case "clear_agent_pid":
+            return clearAgentPID(args)
+
         case "clear_meta":
             return clearMeta(args)
 
@@ -13061,6 +13067,14 @@ class TerminalController {
             return tabResolution.error ?? "ERROR: No tab selected"
         }
 
+        let pidValue: pid_t? = {
+            if let rawPid = normalizedOptionValue(parsed.options["pid"]),
+               let p = Int32(rawPid), p > 0 {
+                return p
+            }
+            return nil
+        }()
+
         DispatchQueue.main.async { [weak self] in
             guard let self, let tab = self.tabForSidebarMutation(id: targetTabId) else { return }
             guard Self.shouldReplaceStatusEntry(
@@ -13073,6 +13087,10 @@ class TerminalController {
                 priority: priority,
                 format: format
             ) else {
+                // Still update PID tracking even if the status display hasn't changed.
+                if let pidValue {
+                    tab.agentPIDs[key] = pidValue
+                }
                 return
             }
             tab.statusEntries[key] = SidebarStatusEntry(
@@ -13085,6 +13103,9 @@ class TerminalController {
                 format: format,
                 timestamp: Date()
             )
+            if let pidValue {
+                tab.agentPIDs[key] = pidValue
+            }
         }
         return "OK"
     }
@@ -13104,10 +13125,50 @@ class TerminalController {
             if tab.statusEntries.removeValue(forKey: key) == nil {
                 result = "OK (key not found)"
             }
+            tab.agentPIDs.removeValue(forKey: key)
         }
         return result
     }
 
+    /// Register an agent PID for stale-session detection without setting a visible status entry.
+    /// Usage: set_agent_pid <key> <pid> [--tab=<id>]
+    private func setAgentPID(_ args: String) -> String {
+        let parsed = parseOptions(args)
+        guard parsed.positional.count >= 2,
+              let pid = Int32(parsed.positional[1]), pid > 0 else {
+            return "ERROR: Usage: set_agent_pid <key> <pid> [--tab=<id>]"
+        }
+        let key = parsed.positional[0]
+        let tabResolution = resolveTabIdForSidebarMutation(reportArgs: args, options: parsed.options)
+        guard let targetTabId = tabResolution.tabId else {
+            return tabResolution.error ?? "ERROR: No tab selected"
+        }
+        DispatchQueue.main.async { [weak self] in
+            guard let self, let tab = self.tabForSidebarMutation(id: targetTabId) else { return }
+            tab.agentPIDs[key] = pid
+        }
+        return "OK"
+    }
+
+    /// Unregister an agent PID. Usage: clear_agent_pid <key> [--tab=<id>]
+    private func clearAgentPID(_ args: String) -> String {
+        let parsed = parseOptions(args)
+        guard let key = parsed.positional.first else {
+            return "ERROR: Usage: clear_agent_pid <key> [--tab=<id>]"
+        }
+        // Resolve tab ID synchronously before dispatching to avoid
+        // racing against selection changes on the main queue.
+        let tabResolution = resolveTabIdForSidebarMutation(reportArgs: args, options: parsed.options)
+        guard let targetTabId = tabResolution.tabId else {
+            return tabResolution.error ?? "ERROR: No tab selected"
+        }
+        DispatchQueue.main.async { [weak self] in
+            guard let self, let tab = self.tabForSidebarMutation(id: targetTabId) else { return }
+            tab.agentPIDs.removeValue(forKey: key)
+        }
+        return "OK"
+    }
+
     private func sidebarMetadataLine(_ entry: SidebarStatusEntry) -> String {
         var line = "\(entry.key)=\(entry.value)"
         if let icon = entry.icon { line += " icon=\(icon)" }

Sources/Workspace.swift

@@ -195,20 +195,11 @@ extension Workspace {
         setCustomColor(snapshot.customColor)
         isPinned = snapshot.isPinned
 
-        statusEntries = Dictionary(
+        // Status entries and agent PIDs are ephemeral runtime state tied to running
-            uniqueKeysWithValues: snapshot.statusEntries.map { entry in
+        // processes (e.g. claude_code "Running"). Don't restore them across app
-                (
+        // restarts because the processes that set them are gone.
-                    entry.key,
+        statusEntries.removeAll()
-                    SidebarStatusEntry(
+        agentPIDs.removeAll()
-                        key: entry.key,
-                        value: entry.value,
-                        icon: entry.icon,
-                        color: entry.color,
-                        timestamp: Date(timeIntervalSince1970: entry.timestamp)
-                    )
-                )
-            }
-        )
         logEntries = snapshot.logEntries.map { entry in
             SidebarLogEntry(
                 message: entry.message,
@@ -1006,6 +997,9 @@ final class Workspace: Identifiable, ObservableObject {
     @Published var listeningPorts: [Int] = []
     var surfaceTTYNames: [UUID: String] = [:]
     private var panelShellActivityStates: [UUID: PanelShellActivityState] = [:]
+    /// PIDs associated with agent status entries (e.g. claude_code), keyed by status key.
+    /// Used for stale-session detection: if the PID is dead, the status entry is cleared.
+    var agentPIDs: [String: pid_t] = [:]
     private var restoredTerminalScrollbackByPanelId: [UUID: String] = [:]
 
     var focusedSurfaceId: UUID? { focusedPanelId }
@@ -1747,6 +1741,7 @@ final class Workspace: Identifiable, ObservableObject {
 
     func resetSidebarContext(reason: String = "unspecified") {
         statusEntries.removeAll()
+        agentPIDs.removeAll()
         logEntries.removeAll()
         progress = nil
         gitBranch = nil

tests/test_claude_wrapper_hooks.py

@@ -139,10 +139,22 @@ def test_live_socket_injects_supported_hooks(failures: list[str]) -> None:
 
     settings = parse_settings_arg(real_argv)
     hooks = settings.get("hooks", {})
-    expect(set(hooks.keys()) == {"SessionStart", "Stop", "Notification"}, f"unexpected hook keys: {hooks.keys()}", failures)
+    expected_hooks = {"SessionStart", "Stop", "SessionEnd", "Notification", "UserPromptSubmit", "PreToolUse"}
-    serialized = json.dumps(settings, sort_keys=True)
+    expect(set(hooks.keys()) == expected_hooks, f"unexpected hook keys: {hooks.keys()}, expected {expected_hooks}", failures)
-    expect("UserPromptSubmit" not in serialized, "UserPromptSubmit hook should not be injected", failures)
+    # PreToolUse should be async to avoid blocking tool execution
-    expect("prompt-submit" not in serialized, "prompt-submit subcommand should not be injected", failures)
+    pre_tool_use_hooks = hooks.get("PreToolUse", [{}])[0].get("hooks", [{}])
+    expect(
+        any(h.get("async") is True for h in pre_tool_use_hooks),
+        f"PreToolUse hook should have async:true, got {pre_tool_use_hooks}",
+        failures,
+    )
+    # SessionEnd should have a short timeout (session is exiting)
+    session_end_hooks = hooks.get("SessionEnd", [{}])[0].get("hooks", [{}])
+    expect(
+        any(h.get("timeout", 999) <= 2 for h in session_end_hooks),
+        f"SessionEnd hook should have short timeout, got {session_end_hooks}",
+        failures,
+    )
 
 
 def test_missing_socket_skips_hook_injection(failures: list[str]) -> None: