feat(mobile): regenerate a thread title from the row menu

apps/mobile/src/features/home/HomeRouteScreen.tsx

@@ -46,6 +46,7 @@ export function HomeRouteScreen() {
     unpinThread,
     movePinnedThread,
     unsettleThread,
+    regenerateThreadTitle,
   } = useThreadListActions();
   const pendingTasks = usePendingNewTasks();
   const { openPendingTask, confirmDeletePendingTask } = usePendingTaskListActions();
@@ -165,6 +166,7 @@ export function HomeRouteScreen() {
           }
           onArchiveThread={archiveThread}
           onDeleteThread={confirmDeleteThread}
+          onRegenerateTitle={regenerateThreadTitle}
           onSettleThread={settleThread}
           onSnoozeThread={snoozeThread}
           onUnsnoozeThread={unsnoozeThread}

apps/mobile/src/features/home/HomeScreen.tsx

@@ -101,6 +101,7 @@ interface HomeScreenProps {
   readonly onSelectThread: (thread: EnvironmentThreadShell) => void;
   readonly onArchiveThread: (thread: EnvironmentThreadShell) => void;
   readonly onDeleteThread: (thread: EnvironmentThreadShell) => void;
+  readonly onRegenerateTitle: (thread: EnvironmentThreadShell) => void;
   /** Resolves true iff the settle was dispatched and succeeded. */
   readonly onSettleThread: (thread: EnvironmentThreadShell) => Promise<boolean>;
   readonly onSnoozeThread: (
@@ -615,6 +616,15 @@ export function HomeScreen(props: HomeScreenProps) {
     }
     return supported;
   }, [serverConfigs]);
+  const titleRegenerationEnvironmentIds = useMemo(() => {
+    const supported = new Set<EnvironmentId>();
+    for (const [environmentId, config] of serverConfigs) {
+      if (config.environment.capabilities.threadTitleRegeneration === true) {
+        supported.add(environmentId);
+      }
+    }
+    return supported;
+  }, [serverConfigs]);
   // Canonical arranged pinned order (reorder-capable threads only) for the
   // Move up/down position flags. Computed from all shells, not the rendered
   // list, so search/scope filtering never disables or misdirects a move.
@@ -811,6 +821,8 @@ export function HomeScreen(props: HomeScreenProps) {
           onSelectThread={props.onSelectThread}
           onDeleteThread={handleDeleteThread}
           onArchiveThread={props.onArchiveThread}
+          onRegenerateTitle={props.onRegenerateTitle}
+          titleRegenerationSupported={titleRegenerationEnvironmentIds.has(thread.environmentId)}
           settlementSupported={settlementEnvironmentIds.has(thread.environmentId)}
           onSettleThread={handleSettleThread}
           snoozeSupported={snoozeEnvironmentIds.has(thread.environmentId)}
@@ -854,13 +866,15 @@ export function HomeScreen(props: HomeScreenProps) {
       projectByKey,
       projectCwdByKey,
       props.onArchiveThread,
+      props.onRegenerateTitle,
       props.onDeletePendingTask,
       props.onSelectPendingTask,
       props.onSelectThread,
       props.savedConnectionsById,
       serverConfigs,
       settlementEnvironmentIds,
       snoozeEnvironmentIds,
+      titleRegenerationEnvironmentIds,
       threadListV2Items,
       threadSearchMatchByKey,
       toggleSettledShelf,
@@ -967,6 +981,8 @@ export function HomeScreen(props: HomeScreenProps) {
               searchQuery={props.searchQuery}
               onArchiveThread={props.onArchiveThread}
               onDeleteThread={props.onDeleteThread}
+              onRegenerateTitle={props.onRegenerateTitle}
+              titleRegenerationSupported={titleRegenerationEnvironmentIds.has(thread.environmentId)}
               onSelectThread={props.onSelectThread}
               onSwipeableClose={handleSwipeableClose}
               onSwipeableWillOpen={handleSwipeableWillOpen}
@@ -992,11 +1008,13 @@ export function HomeScreen(props: HomeScreenProps) {
       props.onArchiveThread,
       props.onDeletePendingTask,
       props.onDeleteThread,
+      props.onRegenerateTitle,
       props.onNewThreadInProject,
       props.onSelectPendingTask,
       props.onSelectThread,
       props.searchQuery,
       props.savedConnectionsById,
+      titleRegenerationEnvironmentIds,
       threadSearchMatchByKey,
       updateGroupDisplay,
     ],

apps/mobile/src/features/home/useThreadListActions.ts

@@ -48,6 +48,15 @@ function environmentSupportsPinReorder(environmentId: EnvironmentThreadShell["en
   );
 }
 
+export function environmentSupportsTitleRegeneration(
+  environmentId: EnvironmentThreadShell["environmentId"],
+) {
+  return (
+    appAtomRegistry.get(environmentServerConfigsAtom).get(environmentId)?.environment.capabilities
+      .threadTitleRegeneration === true
+  );
+}
+
 type ThreadListAction = "archive" | "unarchive" | "delete" | "settle" | "unsettle";
 
 const ACTION_VERBS: Record<ThreadListAction, string> = {
@@ -227,13 +236,18 @@ export function useThreadListActions(): {
     thread: EnvironmentThreadShell,
     direction: "up" | "down",
   ) => Promise<boolean>;
+  readonly regenerateThreadTitle: (thread: EnvironmentThreadShell) => Promise<boolean>;
 } {
   const executeAction = useThreadActionExecutor();
+  const updateMetadataMutation = useAtomCommand(threadEnvironment.updateMetadata, {
+    reportFailure: false,
+  });
   const snoozeMutation = useAtomCommand(threadEnvironment.snooze, { reportFailure: false });
   const unsnoozeMutation = useAtomCommand(threadEnvironment.unsnooze, { reportFailure: false });
   const pinMutation = useAtomCommand(threadEnvironment.pin, { reportFailure: false });
   const unpinMutation = useAtomCommand(threadEnvironment.unpin, { reportFailure: false });
   const snoozeInFlightThreadKeys = useRef(new Set<string>());
+  const regenerateTitleInFlightThreadKeys = useRef(new Set<string>());
 
   const archiveThread = useCallback(
     (thread: EnvironmentThreadShell) => {
@@ -485,6 +499,50 @@ export function useThreadListActions(): {
     [reorderPinnedMutation],
   );
 
+  const regenerateThreadTitle = useCallback(
+    async (thread: EnvironmentThreadShell) => {
+      if (!environmentSupportsTitleRegeneration(thread.environmentId)) {
+        Alert.alert(
+          "Could not regenerate title",
+          "This environment's server does not support title regeneration yet. Update the server to regenerate titles.",
+        );
+        return false;
+      }
+      // Already regenerating: the pending job owns the title until it lands.
+      if (thread.titleRegeneration != null) return false;
+      // Double-dispatch guard: the shell's titleRegeneration flag only flips
+      // once the server event lands, so a second tap before then would slip
+      // past the check above and start duplicate generation work. Same
+      // per-thread in-flight set the snooze actions use.
+      const key = scopedThreadKey(thread.environmentId, thread.id);
+      if (regenerateTitleInFlightThreadKeys.current.has(key)) {
+        return false;
+      }
+      regenerateTitleInFlightThreadKeys.current.add(key);
+      selectionHaptic();
+      try {
+        const result = await updateMetadataMutation({
+          environmentId: thread.environmentId,
+          input: { threadId: thread.id, regenerateTitle: true },
+        });
+        if (result._tag === "Failure") {
+          const error = Cause.squash(result.cause);
+          Alert.alert(
+            "Could not regenerate title",
+            error instanceof Error && error.message.trim().length > 0
+              ? error.message
+              : "The title could not be regenerated.",
+          );
+          return false;
+        }
+        return true;
+      } finally {
+        regenerateTitleInFlightThreadKeys.current.delete(key);
+      }
+    },
+    [updateMetadataMutation],
+  );
+
   const confirmDeleteThread = useConfirmDeleteThread(executeAction);
 
   return {
@@ -497,6 +555,7 @@ export function useThreadListActions(): {
     pinThread,
     unpinThread,
     movePinnedThread,
+    regenerateThreadTitle,
   };
 }
 

apps/mobile/src/features/threads/ThreadNavigationSidebar.tsx

@@ -211,6 +211,7 @@ function ThreadNavigationSidebarPane(
     pinThread,
     unpinThread,
     movePinnedThread,
+    regenerateThreadTitle,
   } = useThreadListActions();
   const threadListV2Enabled = useThreadListV2Enabled();
   const pendingTasks = usePendingNewTasks();
@@ -505,6 +506,15 @@ function ThreadNavigationSidebarPane(
     }
     return supported;
   }, [serverConfigs]);
+  const titleRegenerationEnvironmentIds = useMemo(() => {
+    const supported = new Set<EnvironmentId>();
+    for (const [environmentId, config] of serverConfigs) {
+      if (config.environment.capabilities.threadTitleRegeneration === true) {
+        supported.add(environmentId);
+      }
+    }
+    return supported;
+  }, [serverConfigs]);
   // Canonical arranged pinned order for Move up/down flags — computed from
   // all shells so search/scope filtering never disables a valid move.
   const arrangedPinnedKeys = useMemo(() => {
@@ -950,6 +960,8 @@ function ThreadNavigationSidebarPane(
               onSelectThread={handleSelectThread}
               onDeleteThread={confirmDeleteThread}
               onArchiveThread={archiveThread}
+              onRegenerateTitle={regenerateThreadTitle}
+              titleRegenerationSupported={titleRegenerationEnvironmentIds.has(thread.environmentId)}
               settlementSupported={settlementEnvironmentIds.has(thread.environmentId)}
               onSettleThread={settleThread}
               snoozeSupported={snoozeEnvironmentIds.has(thread.environmentId)}
@@ -1067,6 +1079,8 @@ function ThreadNavigationSidebarPane(
               fullSwipeWidth={props.width - 20}
               onArchiveThread={archiveThread}
               onDeleteThread={confirmDeleteThread}
+              onRegenerateTitle={regenerateThreadTitle}
+              titleRegenerationSupported={titleRegenerationEnvironmentIds.has(thread.environmentId)}
               onSelectThread={handleSelectThread}
               onSwipeableClose={handleSwipeableClose}
               onSwipeableWillOpen={handleSwipeableWillOpen}
@@ -1097,6 +1111,8 @@ function ThreadNavigationSidebarPane(
       handleSwipeableWillOpen,
       movePinnedThread,
       openPendingTask,
+      regenerateThreadTitle,
+      titleRegenerationEnvironmentIds,
       pinReorderEnvironmentIds,
       pinThread,
       pinningEnvironmentIds,

apps/mobile/src/features/threads/thread-list-items.tsx

@@ -409,10 +409,17 @@ export const PendingTaskListRow = memo(function PendingTaskListRow(props: {
 
 /* ─── Thread row ─────────────────────────────────────────────────────── */
 
-const THREAD_ROW_MENU_ACTIONS: MenuAction[] = [
-  { id: "archive", title: "Archive", image: "archivebox" },
-  { id: "delete", title: "Delete", image: "trash", attributes: { destructive: true } },
-];
+const THREAD_ROW_MENU_ARCHIVE: MenuAction = {
+  id: "archive",
+  title: "Archive",
+  image: "archivebox",
+};
+const THREAD_ROW_MENU_DELETE: MenuAction = {
+  id: "delete",
+  title: "Delete",
+  image: "trash",
+  attributes: { destructive: true },
+};
 
 export const ThreadListRow = memo(function ThreadListRow(props: {
   readonly variant: ThreadListVariant;
@@ -429,6 +436,10 @@ export const ThreadListRow = memo(function ThreadListRow(props: {
   readonly onSelectThread: (thread: EnvironmentThreadShell) => void;
   readonly onArchiveThread: (thread: EnvironmentThreadShell) => void;
   readonly onDeleteThread: (thread: EnvironmentThreadShell) => void;
+  /** Adds a "Regenerate title" menu item when provided AND the server
+      supports it (mirrors the web action menu's capability gate). */
+  readonly onRegenerateTitle?: (thread: EnvironmentThreadShell) => void;
+  readonly titleRegenerationSupported?: boolean;
   readonly onSwipeableWillOpen: (methods: SwipeableMethods) => void;
   readonly onSwipeableClose: (methods: SwipeableMethods) => void;
   readonly simultaneousSwipeGesture?: ComponentProps<
@@ -451,6 +462,7 @@ export const ThreadListRow = memo(function ThreadListRow(props: {
   const selectedBackgroundColor = useThemeColor("--color-user-bubble");
 
   const { thread, onSelectThread, onArchiveThread, onDeleteThread } = props;
+  const { onRegenerateTitle } = props;
   const status = resolveThreadStatus(thread);
   const pr = useThreadPr(thread, props.projectCwd);
   const timestamp = relativeTime(
@@ -470,6 +482,33 @@ export const ThreadListRow = memo(function ThreadListRow(props: {
 
   const handleDelete = useCallback(() => onDeleteThread(thread), [onDeleteThread, thread]);
   const handleArchive = useCallback(() => onArchiveThread(thread), [onArchiveThread, thread]);
+  const handleRegenerateTitle = useCallback(
+    () => onRegenerateTitle?.(thread),
+    [onRegenerateTitle, thread],
+  );
+  const showRegenerateTitle =
+    props.titleRegenerationSupported === true && onRegenerateTitle != null;
+  // A regeneration already running owns the title until it lands: disable the
+  // item and label it "Regenerating…" so a second long-press reads as inert
+  // rather than actionable (mirrors web's action menu).
+  const regeneratingTitle = thread.titleRegeneration != null;
+  const menuActions = useMemo<MenuAction[]>(
+    () => [
+      ...(showRegenerateTitle
+        ? [
+            {
+              id: "regenerate-title",
+              title: regeneratingTitle ? "Regenerating…" : "Regenerate title",
+              image: "arrow.clockwise",
+              attributes: { disabled: regeneratingTitle },
+            } satisfies MenuAction,
+          ]
+        : []),
+      THREAD_ROW_MENU_ARCHIVE,
+      THREAD_ROW_MENU_DELETE,
+    ],
+    [regeneratingTitle, showRegenerateTitle],
+  );
   const primaryAction = useMemo(
     () => ({
       accessibilityLabel: `Archive ${thread.title}`,
@@ -481,10 +520,11 @@ export const ThreadListRow = memo(function ThreadListRow(props: {
   );
   const handleMenuAction = useCallback(
     ({ nativeEvent }: { readonly nativeEvent: { readonly event: string } }) => {
+      if (nativeEvent.event === "regenerate-title") handleRegenerateTitle();
       if (nativeEvent.event === "archive") handleArchive();
       if (nativeEvent.event === "delete") handleDelete();
     },
-    [handleArchive, handleDelete],
+    [handleArchive, handleDelete, handleRegenerateTitle],
   );
 
   const statusPill = effectiveStatus ? (
@@ -673,7 +713,7 @@ export const ThreadListRow = memo(function ThreadListRow(props: {
         // ControlPillMenu injects onLongPress into the row and anchors the
         // token-styled dropdown to it; taps and swipes are untouched.
         <ControlPillMenu
-          actions={THREAD_ROW_MENU_ACTIONS}
+          actions={menuActions}
           onPressAction={handleMenuAction}
           shouldOpenOnLongPress
         >