diff --git a/src/main/index.ts b/src/main/index.ts
index 99dc44509f5..5bd19ac61bf 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -27,6 +27,10 @@ import { createMainWindow } from './window/createMainWindow'
 import { CodexAccountService } from './codex-accounts/service'
 
 let mainWindow: BrowserWindow | null = null
+/** Whether a manual app.quit() (Cmd+Q, etc.) is in progress. Shared with the
+ *  window close handler so it can tell the renderer to skip the running-process
+ *  confirmation dialog and proceed directly to buffer capture + close. */
+let isQuitting = false
 let store: Store | null = null
 let stats: StatsCollector | null = null
 let claudeUsage: ClaudeUsageStore | null = null
@@ -75,7 +79,12 @@ function openMainWindow(): BrowserWindow {
     throw new Error('Codex account service must be initialized before opening the main window')
   }
 
-  const window = createMainWindow(store)
+  const window = createMainWindow(store, {
+    getIsQuitting: () => isQuitting,
+    onQuitAborted: () => {
+      isQuitting = false
+    }
+  })
   registerCoreHandlers(
     store,
     runtime,
@@ -169,12 +178,21 @@ app.whenReady().then(async () => {
 })
 
 app.on('before-quit', () => {
+  isQuitting = true
+  // Why: PTY cleanup is deferred to will-quit so the renderer has a chance to
+  // capture terminal scrollback buffers before PTY exit events race in and
+  // unmount TerminalPane components (removing their capture callbacks).
+  // The window close handler passes isQuitting to the renderer so it skips the
+  // child-process confirmation dialog and proceeds directly to buffer capture.
+  rateLimits?.stop()
+})
+
+app.on('will-quit', () => {
   // Why: stats.flush() must run before killAllPty() so it can read the
   // live agent state and emit synthetic agent_stop events for agents that
   // are still running. killAllPty() does not call runtime.onPtyExit(),
   // so without this ordering, running agents would produce orphaned
   // agent_start events with no matching stops.
-  rateLimits?.stop()
   stats?.flush()
   killAllPty()
   void closeAllWatchers()
@@ -187,7 +205,12 @@ app.on('before-quit', () => {
 })
 
 app.on('window-all-closed', () => {
-  if (process.platform !== 'darwin') {
+  // Why: on macOS, closing all windows normally keeps the app alive (dock
+  // stays active). But when a quit is in progress (Cmd+Q), the window close
+  // handler defers to the renderer for buffer capture, which cancels the
+  // original quit sequence. Re-trigger quit here so the app actually exits
+  // instead of requiring a second Cmd+Q.
+  if (process.platform !== 'darwin' || isQuitting) {
     app.quit()
   }
 })
diff --git a/src/main/window/createMainWindow.test.ts b/src/main/window/createMainWindow.test.ts
index 58f12c0e7ce..811b68983be 100644
--- a/src/main/window/createMainWindow.test.ts
+++ b/src/main/window/createMainWindow.test.ts
@@ -318,8 +318,24 @@ describe('createMainWindow', () => {
 
     const isDarwin = process.platform === 'darwin'
     for (const input of [
-      { type: 'keyDown', code: 'KeyJ', key: 'j', meta: isDarwin, control: !isDarwin, alt: false, shift: !isDarwin },
-      { type: 'keyDown', code: 'KeyJ', key: '', meta: isDarwin, control: !isDarwin, alt: false, shift: !isDarwin }
+      {
+        type: 'keyDown',
+        code: 'KeyJ',
+        key: 'j',
+        meta: isDarwin,
+        control: !isDarwin,
+        alt: false,
+        shift: !isDarwin
+      },
+      {
+        type: 'keyDown',
+        code: 'KeyJ',
+        key: '',
+        meta: isDarwin,
+        control: !isDarwin,
+        alt: false,
+        shift: !isDarwin
+      }
     ]) {
       const preventDefault = vi.fn()
       windowHandlers['before-input-event']({ preventDefault } as never, input as never)
@@ -377,4 +393,47 @@ describe('createMainWindow', () => {
     expect(webContents.openDevTools).toHaveBeenCalledWith({ mode: 'undocked' })
     expect(webContents.closeDevTools).not.toHaveBeenCalled()
   })
+
+  it('clears the quit latch when the renderer prevents unload', () => {
+    const windowHandlers: Record<string, (...args: any[]) => void> = {}
+    const webContents = {
+      on: vi.fn((event, handler) => {
+        windowHandlers[event] = handler
+      }),
+      setZoomLevel: vi.fn(),
+      setBackgroundThrottling: vi.fn(),
+      invalidate: vi.fn(),
+      setWindowOpenHandler: vi.fn(),
+      send: vi.fn()
+    }
+    const browserWindowInstance = {
+      webContents,
+      on: vi.fn((event, handler) => {
+        windowHandlers[event] = handler
+      }),
+      isDestroyed: vi.fn(() => false),
+      isMaximized: vi.fn(() => true),
+      isFullScreen: vi.fn(() => false),
+      getSize: vi.fn(() => [1200, 800]),
+      setSize: vi.fn(),
+      maximize: vi.fn(),
+      show: vi.fn(),
+      loadFile: vi.fn(),
+      loadURL: vi.fn()
+    }
+    const onQuitAborted = vi.fn()
+    browserWindowMock.mockImplementation(function () {
+      return browserWindowInstance
+    })
+
+    createMainWindow(null, { getIsQuitting: () => true, onQuitAborted })
+
+    const preventDefault = vi.fn()
+    windowHandlers.close({ preventDefault } as never)
+    expect(preventDefault).toHaveBeenCalledTimes(1)
+    expect(webContents.send).toHaveBeenCalledWith('window:close-requested', { isQuitting: true })
+
+    windowHandlers['will-prevent-unload']()
+    expect(onQuitAborted).toHaveBeenCalledTimes(1)
+  })
 })
diff --git a/src/main/window/createMainWindow.ts b/src/main/window/createMainWindow.ts
index cc1d8b374d1..6d7c604f13c 100644
--- a/src/main/window/createMainWindow.ts
+++ b/src/main/window/createMainWindow.ts
@@ -45,7 +45,22 @@ function syncTrafficLightPosition(win: BrowserWindow, zoomFactor: number): void
   win.setWindowButtonPosition({ x: TRAFFIC_LIGHT_X, y })
 }
 
-export function createMainWindow(store: Store | null): BrowserWindow {
+type CreateMainWindowOptions = {
+  /** Returns true when a manual app.quit() (Cmd+Q) is in progress. The close
+   *  handler sends this to the renderer so it can skip the running-process
+   *  confirmation dialog and proceed directly to buffer capture + close. */
+  getIsQuitting?: () => boolean
+  /** Notifies the caller when the renderer vetoes unload. Why: a prevented
+   *  beforeunload cancels the in-flight app.quit(), so the app-level quit
+   *  latch must be cleared or later window closes will be misclassified as
+   *  quit attempts. */
+  onQuitAborted?: () => void
+}
+
+export function createMainWindow(
+  store: Store | null,
+  opts?: CreateMainWindowOptions
+): BrowserWindow {
   const mainWindow = new BrowserWindow({
     width: 1200,
     height: 800,
@@ -258,7 +273,12 @@ export function createMainWindow(store: Store | null): BrowserWindow {
       return
     }
     e.preventDefault()
-    mainWindow.webContents.send('window:close-requested')
+    mainWindow.webContents.send('window:close-requested', {
+      isQuitting: opts?.getIsQuitting?.() ?? false
+    })
+  })
+  mainWindow.webContents.on('will-prevent-unload', () => {
+    opts?.onQuitAborted?.()
   })
 
   const onConfirmClose = (): void => {
diff --git a/src/preload/api-types.d.ts b/src/preload/api-types.d.ts
index c5e84b43b35..c3af3683ea3 100644
--- a/src/preload/api-types.d.ts
+++ b/src/preload/api-types.d.ts
@@ -376,7 +376,7 @@ export type PreloadApi = {
     setZoomLevel: (level: number) => void
     syncTrafficLights: (zoomFactor: number) => void
     onFullscreenChanged: (callback: (isFullScreen: boolean) => void) => () => void
-    onWindowCloseRequested: (callback: () => void) => () => void
+    onWindowCloseRequested: (callback: (data: { isQuitting: boolean }) => void) => () => void
     confirmWindowClose: () => void
   }
   runtime: {
diff --git a/src/preload/index.ts b/src/preload/index.ts
index 8d646a6de2b..69456eb6cec 100644
--- a/src/preload/index.ts
+++ b/src/preload/index.ts
@@ -672,9 +672,12 @@ const api = {
     },
     /** Fired by the main process when the user tries to close the window
      *  (X button, Cmd+Q, etc.). Renderer should show a confirmation dialog
-     *  if terminals are still running, then call confirmWindowClose(). */
-    onWindowCloseRequested: (callback: () => void): (() => void) => {
-      const listener = () => callback()
+     *  if terminals are still running, then call confirmWindowClose().
+     *  When isQuitting is true, the close was initiated by app.quit() (Cmd+Q)
+     *  and the renderer should skip the running-process dialog. */
+    onWindowCloseRequested: (callback: (data: { isQuitting: boolean }) => void): (() => void) => {
+      const listener = (_event: Electron.IpcRendererEvent, data: { isQuitting: boolean }) =>
+        callback(data ?? { isQuitting: false })
       ipcRenderer.on('window:close-requested', listener)
       return () => ipcRenderer.removeListener('window:close-requested', listener)
     },
diff --git a/src/renderer/src/App.tsx b/src/renderer/src/App.tsx
index 826360ab69e..5b3c9aeae8d 100644
--- a/src/renderer/src/App.tsx
+++ b/src/renderer/src/App.tsx
@@ -252,7 +252,18 @@ function App(): React.JSX.Element {
   // On shutdown, capture terminal scrollback buffers and flush to disk.
   // Runs synchronously in beforeunload: capture → Zustand set → sendSync → flush.
   useEffect(() => {
+    // Why: beforeunload fires twice during a manual quit — once from the
+    // synthetic dispatch in the onWindowCloseRequested handler (captures
+    // good data while TerminalPanes are still mounted), and again from the
+    // native window close triggered by confirmWindowClose(). Between these
+    // two firings, PTY exit events can arrive and unmount TerminalPanes,
+    // emptying shutdownBufferCaptures. The guard prevents the second call
+    // from overwriting the good session data with an empty snapshot.
+    let shutdownBuffersCaptured = false
     const captureAndFlush = (): void => {
+      if (shutdownBuffersCaptured) {
+        return
+      }
       if (!useAppStore.getState().workspaceSessionReady) {
         return
       }
@@ -265,17 +276,16 @@ function App(): React.JSX.Element {
       }
       const state = useAppStore.getState()
       window.api.session.setSync(buildWorkspaceSessionPayload(state))
+      shutdownBuffersCaptured = true
     }
     window.addEventListener('beforeunload', captureAndFlush)
     return () => window.removeEventListener('beforeunload', captureAndFlush)
   }, [])
 
   // Periodically capture terminal scrollback buffers and persist to disk.
-  // Why: the normal shutdown path races with PTY exit events — before-quit
-  // kills all PTYs, whose async exit handlers close tabs and unmount
-  // TerminalPane components (removing their capture callbacks) before the
-  // renderer's beforeunload can run. Periodic saves ensure scrollback is
-  // available on restart even when the shutdown capture is lost.
+  // Why: the shutdown path captures buffers in beforeunload, but periodic
+  // saves provide a safety net so scrollback is available on restart even
+  // if an unexpected exit (crash, force-kill) bypasses normal shutdown.
   useEffect(() => {
     const PERIODIC_SAVE_INTERVAL_MS = 3 * 60_000
     const timer = window.setInterval(() => {
diff --git a/src/renderer/src/components/Terminal.tsx b/src/renderer/src/components/Terminal.tsx
index 884b2c59db7..e2782ebf8f6 100644
--- a/src/renderer/src/components/Terminal.tsx
+++ b/src/renderer/src/components/Terminal.tsx
@@ -608,18 +608,24 @@ export default function Terminal(): React.JSX.Element | null {
   // Listen for main-process window close requests. When any terminal has a
   // child process running (not just an idle shell), show a confirmation dialog.
   useEffect(() => {
-    return window.api.ui.onWindowCloseRequested(() => {
+    return window.api.ui.onWindowCloseRequested(({ isQuitting }) => {
       if (isUpdaterQuitAndInstallInProgress()) {
         window.api.ui.confirmWindowClose()
         return
       }
-      // Why: before-quit (main process) kills all PTYs before this handler
-      // runs. The async PTY exit events close tabs and unmount TerminalPane
-      // components, removing their buffer capture callbacks. Dispatching
-      // beforeunload here — while components are still mounted — captures
-      // scrollback buffers before the race can discard them. This mirrors
-      // the auto-updater path (preload/index.ts) which does the same thing.
+      // Why: capture terminal scrollback buffers while TerminalPane components
+      // are still mounted. Dispatching beforeunload triggers the App.tsx
+      // captureAndFlush handler which serializes each pane's xterm buffer
+      // and writes the session to disk via synchronous IPC.
       window.dispatchEvent(new Event('beforeunload'))
+      // Why: during a quit (Cmd+Q), PTYs are still alive (cleanup is deferred
+      // to will-quit so buffers can be captured first). Skip the child-process
+      // confirmation dialog and proceed directly — the user's intent to quit
+      // is unambiguous.
+      if (isQuitting) {
+        window.api.ui.confirmWindowClose()
+        return
+      }
       const state = useAppStore.getState()
       const allPtyIds = Object.values(state.ptyIdsByTabId).flat()
       if (allPtyIds.length === 0) {