fix(offline): address PR #120 review (comment 2513)

CHANGELOG: stop presenting the service-worker API cache as an active offline
store (/api is NetworkOnly) — describe it as a defensive purge of the legacy
api-get-cache from older clients; add an explicit upgrade note that the new CORS
allowlist rejects previously-allowed cross-domain REST clients until their origin
is added to CORS_ALLOWED_ORIGINS.

test(offline): cover make-offline ancestor-walk + dedup — a real-ancestor case
exercising the ancestorId===pageId guard (page warmed once), the dedup of
repeated tree failures into a single "tree" label, and the "breadcrumbs" label
when the breadcrumbs lookup rejects.

test(auth): cover clearOfflineCache in handleLogout — purged exactly once before
window.location.replace, and a thrown purge error does not block the redirect.

conventions: use pageKeys.detail() instead of raw ["pages", …] literals in
title-editor and use-page-collab-providers.

cleanup: remove the dead emit() in title-editor (the gateway ignores it; the
cross-user tree refresh is server-side via the Yjs title fragment); drop the
trivial Array.isArray(tiptapExtensions) test (schema is exercised transitively).

refactor: extract the shared page.<id> Yjs doc-name convention into
pageYdocName()/PAGE_YDOC_NAME_PREFIX so the editor providers, offline warm, and
offline purge can no longer drift apart.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.env.example

@@ -92,6 +92,19 @@ IFRAME_EMBED_ALLOWED=false
 # Example: https://intranet.example.com,https://portal.example.com
 IFRAME_ALLOWED_ORIGINS=
 
+# Comma-separated list of additional origins allowed to call the API via CORS.
+# The APP_URL origin and native mobile (Capacitor) origins are always allowed.
+# Leave empty for a same-origin (web-only) deployment.
+CORS_ALLOWED_ORIGINS=
+
+# Expose OpenAPI/Swagger docs at /api/docs (development/debugging aid only).
+SWAGGER_ENABLED=false
+
+# Capacitor (mobile shell): hosted client URL loaded by the iOS shell so the
+# AGPL web client is NOT bundled into the .ipa (see docs/mobile-app-plan.md §9).
+# Leave empty for Android bundled mode / local development.
+CAP_SERVER_URL=
+
 # Enable debug logging in production (default: false)
 DEBUG_MODE=false
 

.gitignore

@@ -49,3 +49,8 @@ lerna-debug.log*
 
 # Self-hosted VAD / onnxruntime-web assets (copied from node_modules at dev/build time)
 apps/client/public/vad/
+
+# Capacitor native platform projects (generated locally via 'npx cap add ios|android')
+/ios
+/android
+.capacitor

CHANGELOG.md

@@ -67,6 +67,33 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   toggle. Previously the create call defaulted to including sub-pages, silently
   exposing every child of a freshly shared page. (#216)
 
+- **Offline reading support**: opened pages, their sidebar tree, breadcrumb
+  children, and comments are cached in IndexedDB (TanStack Query persister plus
+  `y-indexeddb` for the page's Yjs document), and a PWA service worker
+  (vite-plugin-pwa) serves an app shell so previously opened pages stay readable
+  offline. The two offline stores (the persisted query cache and the Yjs page
+  documents) are cleared on logout AND on sign-in so a previous user's private
+  data does not remain in the browser; the same purge also defensively drops any
+  legacy service-worker `api-get-cache` left by older clients (current builds
+  serve `/api` as NetworkOnly, so there is no active service-worker API cache).
+- **Mobile bootstrap**: a `returnToken` opt-in on login so native/mobile clients
+  can request the access JWT in the response body (`data.authToken`) in addition
+  to the httpOnly cookie (the web client stays cookie-only); an optional
+  OpenAPI/Swagger UI at `/api/docs` gated by `SWAGGER_ENABLED` (off by default);
+  and new env vars `CORS_ALLOWED_ORIGINS`, `SWAGGER_ENABLED`, `CAP_SERVER_URL`.
+
+### Changed
+
+- **CORS is now an explicit allowlist** (replaces the previous unconfigured
+  `app.enableCors()`). The same-origin web client is unaffected, but any
+  separately-hosted cross-domain client must now be listed in
+  `CORS_ALLOWED_ORIGINS` (native Capacitor/Ionic/localhost WebView origins are
+  allowed automatically). Requests with no `Origin` header (server-to-server)
+  are still allowed. **Upgrade note:** the old bare `app.enableCors()` reflected
+  *any* origin (with `credentials:false`), so any previously-working cross-domain
+  REST/browser client is now rejected until its origin is added to
+  `CORS_ALLOWED_ORIGINS` (see `.env.example`).
+
 ### Fixed
 
 - **Internal links in exported Markdown no longer lose their visible text.** A

apps/client/index.html

@@ -10,6 +10,7 @@
     <meta name="theme-color" content="#0E1117" media="(prefers-color-scheme: dark)" />
     <meta name="theme-color" content="#f6f7f9" media="(prefers-color-scheme: light)" />
     <link rel="manifest" href="/manifest.json" />
+    <link rel="apple-touch-icon" href="/icons/app-icon-192x192.png" />
     <meta name="mobile-web-app-capable" content="yes" />
     <meta name="apple-touch-fullscreen" content="yes" />
     <meta name="apple-mobile-web-app-title" content="Gitmost" />

apps/client/package.json

@@ -33,7 +33,9 @@
     "@slidoapp/emoji-mart-data": "1.2.4",
     "@slidoapp/emoji-mart-react": "1.1.5",
     "@tabler/icons-react": "3.40.0",
+    "@tanstack/query-async-storage-persister": "5.90.17",
     "@tanstack/react-query": "5.90.17",
+    "@tanstack/react-query-persist-client": "5.90.17",
     "@tanstack/react-virtual": "3.13.24",
     "ai": "6.0.207",
     "alfaaz": "1.1.0",
@@ -45,6 +47,7 @@
     "highlightjs-sap-abap": "0.3.0",
     "i18next": "25.10.1",
     "i18next-http-backend": "3.0.6",
+    "idb-keyval": "6.2.5",
     "jotai": "2.18.1",
     "jotai-optics": "0.4.0",
     "js-cookie": "3.0.7",
@@ -95,6 +98,7 @@
     "typescript": "5.9.3",
     "typescript-eslint": "8.57.1",
     "vite": "8.0.5",
+    "vite-plugin-pwa": "1.3.0",
     "vitest": "4.1.6"
   }
 }

apps/client/public/locales/en-US/translation.json

@@ -464,6 +464,18 @@
   "Move page": "Move page",
   "Move page to a different space.": "Move page to a different space.",
   "Real-time editor connection lost. Retrying...": "Real-time editor connection lost. Retrying...",
+  "Offline — changes are saved locally and will sync when you reconnect": "Offline — changes are saved locally and will sync when you reconnect",
+  "Syncing changes…": "Syncing changes…",
+  "All changes synced": "All changes synced",
+  "Update available": "Update available",
+  "Reload": "Reload",
+  "Make available offline": "Make available offline",
+  "Saving page for offline use...": "Saving page for offline use...",
+  "Page is now available offline": "Page is now available offline",
+  "Failed to make page available offline": "Failed to make page available offline",
+  "You're offline": "You're offline",
+  "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.": "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.",
+  "Retry": "Retry",
   "Table of contents": "Table of contents",
   "Add headings (H1, H2, H3) to generate a table of contents.": "Add headings (H1, H2, H3) to generate a table of contents.",
   "Share": "Share",

apps/client/public/locales/ru-RU/translation.json

@@ -474,6 +474,18 @@
   "Move page": "Переместить страницу",
   "Move page to a different space.": "Переместите страницу в другое пространство.",
   "Real-time editor connection lost. Retrying...": "Соединение с редактором в реальном времени потеряно. Повторная попытка...",
+  "Offline — changes are saved locally and will sync when you reconnect": "Нет сети — изменения сохраняются локально и синхронизируются при восстановлении соединения",
+  "Syncing changes…": "Синхронизация изменений…",
+  "All changes synced": "Все изменения синхронизированы",
+  "Update available": "Доступно обновление",
+  "Reload": "Перезагрузить",
+  "Make available offline": "Сделать доступным офлайн",
+  "Saving page for offline use...": "Сохраняем страницу для офлайн-доступа…",
+  "Page is now available offline": "Страница доступна офлайн",
+  "Failed to make page available offline": "Не удалось сделать страницу доступной офлайн",
+  "You're offline": "Вы офлайн",
+  "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.": "Эта страница не была сохранена для офлайн-доступа, поэтому её нельзя загрузить сейчас. Подключитесь к интернету и попробуйте снова.",
+  "Retry": "Повторить",
   "Table of contents": "Оглавление",
   "Add headings (H1, H2, H3) to generate a table of contents.": "Добавьте заголовки (H1, H2, H3), чтобы создать оглавление.",
   "Share": "Поделиться",

apps/client/public/manifest.json

@@ -1,30 +1,19 @@
 {
+  "id": "/",
   "name": "Gitmost",
   "short_name": "Gitmost",
+  "description": "Gitmost - open-source collaborative documentation and knowledge base.",
+  "lang": "en",
   "start_url": "/",
+  "scope": "/",
   "display": "standalone",
+  "orientation": "any",
   "background_color": "#0E1117",
   "theme_color": "#0E1117",
   "icons": [
-    {
-      "src": "icons/favicon-16x16.png",
-      "type": "image/png",
-      "sizes": "16x16"
-    },
-    {
-      "src": "icons/favicon-32x32.png",
-      "type": "image/png",
-      "sizes": "32x32"
-    },
-    {
-      "src": "icons/app-icon-192x192.png",
-      "type": "image/png",
-      "sizes": "180x180 192x192"
-    },
-    {
-      "src": "icons/app-icon-512x512.png",
-      "type": "image/png",
-      "sizes": "512x512"
-    }
+    { "src": "icons/favicon-16x16.png", "type": "image/png", "sizes": "16x16" },
+    { "src": "icons/favicon-32x32.png", "type": "image/png", "sizes": "32x32" },
+    { "src": "icons/app-icon-192x192.png", "type": "image/png", "sizes": "192x192", "purpose": "any" },
+    { "src": "icons/app-icon-512x512.png", "type": "image/png", "sizes": "512x512", "purpose": "any" }
   ]
 }

apps/client/src/features/auth/hooks/use-auth.test.ts

@@ -0,0 +1,154 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { renderHook, act } from "@testing-library/react";
+
+// react-i18next: identity t() so the hook renders without an i18n provider.
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => k }),
+}));
+
+// react-router-dom: only useNavigate is used by the hook.
+const navigateMock = vi.fn();
+vi.mock("react-router-dom", () => ({
+  useNavigate: () => navigateMock,
+}));
+
+// The auth service is the network boundary; stub login/logout per test.
+const loginMock = vi.fn();
+const logoutMock = vi.fn();
+vi.mock("@/features/auth/services/auth-service", () => ({
+  login: (...args: unknown[]) => loginMock(...args),
+  logout: (...args: unknown[]) => logoutMock(...args),
+  forgotPassword: vi.fn(),
+  passwordReset: vi.fn(),
+  setupWorkspace: vi.fn(),
+  verifyUserToken: vi.fn(),
+}));
+
+vi.mock("@/features/workspace/services/workspace-service.ts", () => ({
+  acceptInvitation: vi.fn(),
+}));
+
+// The offline cache purge is the unit under test — assert it is invoked.
+const clearOfflineCacheMock = vi.fn();
+vi.mock("@/features/offline/clear-offline-cache", () => ({
+  clearOfflineCache: () => clearOfflineCacheMock(),
+}));
+
+// app-route helpers are pure config; provide deterministic values.
+vi.mock("@/lib/app-route.ts", () => ({
+  default: { AUTH: { LOGIN: "/login" }, HOME: "/home" },
+  getPostLoginRedirect: () => "/home",
+}));
+
+// Mantine notifications: avoid touching the DOM-bound notification system.
+vi.mock("@mantine/notifications", () => ({
+  notifications: { show: vi.fn() },
+}));
+
+import useAuth from "./use-auth";
+
+beforeEach(() => {
+  navigateMock.mockReset();
+  loginMock.mockReset();
+  loginMock.mockResolvedValue(undefined);
+  logoutMock.mockReset();
+  logoutMock.mockResolvedValue(undefined);
+  clearOfflineCacheMock.mockReset();
+  clearOfflineCacheMock.mockResolvedValue(undefined);
+});
+
+describe("useAuth.handleSignIn", () => {
+  it("clears the offline cache BEFORE logging in (cross-user leak guard)", async () => {
+    const order: string[] = [];
+    clearOfflineCacheMock.mockImplementation(async () => {
+      order.push("clear");
+    });
+    loginMock.mockImplementation(async () => {
+      order.push("login");
+    });
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.signIn({ email: "b@x", password: "pw" } as any);
+    });
+
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    expect(loginMock).toHaveBeenCalledTimes(1);
+    // The purge must run before the new session's login resolves.
+    expect(order).toEqual(["clear", "login"]);
+    expect(navigateMock).toHaveBeenCalledWith("/home");
+  });
+
+  it("does not block sign-in when the cache purge throws (best-effort)", async () => {
+    clearOfflineCacheMock.mockRejectedValue(new Error("idb unavailable"));
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.signIn({ email: "b@x", password: "pw" } as any);
+    });
+
+    // Login still proceeds despite the cleanup failure.
+    expect(loginMock).toHaveBeenCalledTimes(1);
+    expect(navigateMock).toHaveBeenCalledWith("/home");
+  });
+});
+
+describe("useAuth.handleLogout", () => {
+  const replaceMock = vi.fn();
+  let originalLocation: Location;
+
+  beforeEach(() => {
+    replaceMock.mockReset();
+    // window.location.replace is the post-logout redirect. jsdom's real `replace`
+    // is a non-configurable method that warns "not implemented", so swap the
+    // whole location object for one whose `replace` we can capture.
+    originalLocation = window.location;
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      writable: true,
+      value: { replace: replaceMock },
+    });
+  });
+
+  afterEach(() => {
+    Object.defineProperty(window, "location", {
+      configurable: true,
+      writable: true,
+      value: originalLocation,
+    });
+  });
+
+  it("purges the offline cache exactly once BEFORE redirecting (cross-user leak guard)", async () => {
+    const order: string[] = [];
+    clearOfflineCacheMock.mockImplementation(async () => {
+      order.push("clear");
+    });
+    replaceMock.mockImplementation((url: string) => {
+      order.push(`replace:${url}`);
+    });
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.logout();
+    });
+
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    // Purge must complete before the redirect (which would otherwise interrupt
+    // the async cleanup).
+    expect(order).toEqual(["clear", "replace:/login?logout=1"]);
+  });
+
+  it("still redirects when the cache purge throws (best-effort, never blocks logout)", async () => {
+    clearOfflineCacheMock.mockRejectedValue(new Error("idb unavailable"));
+
+    const { result } = renderHook(() => useAuth());
+    await act(async () => {
+      await result.current.logout();
+    });
+
+    // The thrown purge error is swallowed and the redirect still fires.
+    expect(clearOfflineCacheMock).toHaveBeenCalledTimes(1);
+    expect(replaceMock).toHaveBeenCalledTimes(1);
+    expect(replaceMock).toHaveBeenCalledWith("/login?logout=1");
+  });
+});

apps/client/src/features/auth/hooks/use-auth.ts

@@ -23,6 +23,7 @@ import { acceptInvitation } from "@/features/workspace/services/workspace-servic
 import APP_ROUTE, { getPostLoginRedirect } from "@/lib/app-route.ts";
 import { RESET } from "jotai/utils";
 import { useTranslation } from "react-i18next";
+import { clearOfflineCache } from "@/features/offline/clear-offline-cache";
 
 export default function useAuth() {
   const { t } = useTranslation();
@@ -33,6 +34,20 @@ export default function useAuth() {
   const handleSignIn = async (data: ILogin) => {
     setIsLoading(true);
 
+    // Purge any previous user's offline data BEFORE signing in (mirrors logout).
+    // On a shared/kiosk device the prior session may have ended WITHOUT an
+    // explicit logout (cookie/JWT expiry, tab close, force-quit), leaving user
+    // A's persisted query cache (gitmost-rq-cache) and Yjs page bodies
+    // (page.<id>) in IndexedDB. Without this purge user B would briefly read A's
+    // cached currentUser/pages/comments on first render (UserProvider serves the
+    // cached user) and A's page bodies would stay readable offline. Best-effort:
+    // never block sign-in on cache cleanup.
+    try {
+      await clearOfflineCache();
+    } catch {
+      // best-effort: never block sign-in on cache cleanup
+    }
+
     try {
       await login(data);
       setIsLoading(false);
@@ -123,6 +138,13 @@ export default function useAuth() {
   const handleLogout = async () => {
     setCurrentUser(RESET);
     await logout();
+    // Purge the previous user's offline data while the page is still alive —
+    // window.location.replace below would otherwise interrupt async cleanup.
+    try {
+      await clearOfflineCache();
+    } catch {
+      // best-effort: never block logout on cache cleanup
+    }
     window.location.replace(`${APP_ROUTE.AUTH.LOGIN}?logout=1`);
   };
 

apps/client/src/features/auth/queries/auth-query.test.ts

@@ -0,0 +1,43 @@
+import { describe, it, expect } from "vitest";
+import { AxiosError } from "axios";
+import { collabTokenRetry } from "./auth-query";
+
+// Regression for the offline white-screen (#237/#238): offline the collab-token
+// POST rejects as an axios NETWORK error (isAxiosError === true but
+// error.response === undefined). The old predicate read `error.response.status`
+// without a guard and threw an uncaught TypeError inside the React Query retryer
+// BEFORE React mounted, blanking the whole app. The predicate must stay total.
+describe("collabTokenRetry", () => {
+  it("does NOT throw and returns a retryable value for a network error with no response (offline)", () => {
+    // An axios error with no `response` is exactly the offline/network-failure shape.
+    const networkError = new AxiosError("Network Error");
+    expect(networkError.response).toBeUndefined();
+
+    let result: boolean | number = false;
+    expect(() => {
+      result = collabTokenRetry(0, networkError);
+    }).not.toThrow();
+    // Network failures stay retryable (truthy), matching the original intent.
+    expect(result).toBe(true);
+  });
+
+  it("returns false (no retry) for a real 404 response", () => {
+    const notFound = new AxiosError("Not Found");
+    notFound.response = { status: 404 } as AxiosError["response"];
+    expect(collabTokenRetry(0, notFound)).toBe(false);
+  });
+
+  it("retries for a non-404 response (e.g. 500)", () => {
+    const serverError = new AxiosError("Server Error");
+    serverError.response = { status: 500 } as AxiosError["response"];
+    expect(collabTokenRetry(0, serverError)).toBe(true);
+  });
+
+  it("does not throw and retries for a non-axios error", () => {
+    let result: boolean | number = false;
+    expect(() => {
+      result = collabTokenRetry(0, new Error("boom"));
+    }).not.toThrow();
+    expect(result).toBe(true);
+  });
+});

apps/client/src/features/auth/queries/auth-query.tsx

@@ -3,6 +3,27 @@ import { getCollabToken, verifyUserToken } from "../services/auth-service";
 import { ICollabToken, IVerifyUserToken } from "../types/auth.types";
 import { isAxiosError } from "axios";
 
+/**
+ * Retry predicate for the collab-token query.
+ *
+ * Offline (or any network failure) the POST rejects as an axios NETWORK error:
+ * `isAxiosError(error) === true` but `error.response === undefined`. Reading
+ * `error.response.status` without a guard threw an uncaught TypeError inside the
+ * React Query retryer BEFORE React mounted, white-screening the whole app on an
+ * offline cold boot (#237/#238). Optional-chaining `error.response?.status`
+ * keeps the predicate total: a network error (no response) is retryable, a real
+ * 404 is not. Extracted (and exported) so it can be unit-tested in isolation.
+ */
+export function collabTokenRetry(
+  _failureCount: number,
+  error: Error,
+): boolean {
+  if (isAxiosError(error) && error.response?.status === 404) {
+    return false;
+  }
+  return true;
+}
+
 export function useVerifyUserTokenQuery(
   verify: IVerifyUserToken,
 ): UseQueryResult<any, Error> {
@@ -22,13 +43,7 @@ export function useCollabToken(): UseQueryResult<ICollabToken, Error> {
     //refetchInterval: 12 * 60 * 60 * 1000, // 12hrs
     //refetchIntervalInBackground: true,
     refetchOnMount: true,
-    //@ts-ignore
-    retry: (failureCount, error) => {
-      if (isAxiosError(error) && error.response.status === 404) {
-        return false;
-      }
-      return 10;
-    },
+    retry: collabTokenRetry,
     retryDelay: (retryAttempt) => {
       // Exponential backoff: 5s, 10s, 20s, etc.
       return 5000 * Math.pow(2, retryAttempt - 1);

apps/client/src/features/comment/queries/comment-query.ts

@@ -20,6 +20,7 @@ import { notifications } from "@mantine/notifications";
 import { IPagination } from "@/lib/types.ts";
 import { useTranslation } from "react-i18next";
 import { useEffect, useMemo } from "react";
+import { offlineMutationKeys } from "@/features/offline/offline-mutations";
 
 export const RQ_KEY = (pageId: string) => ["comments", pageId];
 
@@ -60,6 +61,9 @@ export function useCreateCommentMutation() {
   const { t } = useTranslation();
 
   return useMutation<IComment, Error, Partial<IComment>>({
+    // Stable key so a paused comment-create restored from IndexedDB after an
+    // offline reload finds its default mutationFn and is replayed on reconnect.
+    mutationKey: offlineMutationKeys.createComment,
     mutationFn: (data) => createComment(data),
     onSuccess: (newComment) => {
       const cache = queryClient.getQueryData(

apps/client/src/features/editor/atoms/editor-atoms.ts

@@ -10,6 +10,12 @@ export const readOnlyEditorAtom = atom<Editor | null>(null);
 
 export const yjsConnectionStatusAtom = atom<string>("");
 
+// Local (IndexedDB) persistence sync state for the current page's Y.Doc.
+export const isLocalSyncedAtom = atom<boolean>(false);
+
+// Remote (Hocuspocus) sync state for the current page's Y.Doc.
+export const isRemoteSyncedAtom = atom<boolean>(false);
+
 export const showLinkMenuAtom = atom(false);
 
 // Current page's edit mode — initialized from the user's saved preference on

apps/client/src/features/editor/contexts/editor-providers-context.tsx

@@ -0,0 +1,21 @@
+import { createContext, useContext } from "react";
+import type { HocuspocusProvider } from "@hocuspocus/provider";
+import type * as Y from "yjs";
+
+// Shared collaboration providers lifted above the title/body editors so that
+// both siblings bind to the SAME Y.Doc and HocuspocusProvider. The title lives
+// in a dedicated 'title' fragment of the same doc as the body.
+export interface EditorProvidersContextValue {
+  ydoc: Y.Doc;
+  remote: HocuspocusProvider;
+  providersReady: boolean;
+}
+
+export const EditorProvidersContext =
+  createContext<EditorProvidersContextValue | null>(null);
+
+// Returns the shared providers, or null when rendered outside of a provider.
+// Consumers must be null-safe (the body editor falls back to a non-collab mode).
+export function useEditorProviders(): EditorProvidersContextValue | null {
+  return useContext(EditorProvidersContext);
+}

apps/client/src/features/editor/full-editor.tsx

@@ -34,6 +34,8 @@ import {
 } from "@/features/editor/atoms/editor-atoms.ts";
 import { DictationGroup } from "@/features/editor/components/fixed-toolbar/groups/dictation-group";
 import { GenerateTitleGroup } from "@/features/editor/components/fixed-toolbar/groups/generate-title-group";
+import { usePageCollabProviders } from "@/features/editor/hooks/use-page-collab-providers";
+import { EditorProvidersContext } from "@/features/editor/contexts/editor-providers-context";
 
 const MemoizedTitleEditor = React.memo(TitleEditor);
 const MemoizedPageEditor = React.memo(PageEditor);
@@ -90,6 +92,10 @@ export function FullEditor({
     user.settings?.preferences?.pageEditMode ?? PageEditMode.Edit;
   const isEditMode = currentPageEditMode === PageEditMode.Edit;
 
+  // Single shared Y.Doc + HocuspocusProvider for both the title and body
+  // editors (title lives in the 'title' fragment of the same doc).
+  const { ydoc, remote, providersReady } = usePageCollabProviders(pageId);
+
   // Apply the user's saved preference only once on initial load, not on every
   // page navigation — so the mode sticks across navigations within a session.
   useEffect(() => {
@@ -110,28 +116,32 @@ export function FullEditor({
       )}
       <MemoizedDeletedPageBanner slugId={slugId} />
       <MemoizedTemporaryNoteBanner slugId={slugId} />
-      <MemoizedTitleEditor
-        pageId={pageId}
-        slugId={slugId}
-        title={title}
-        spaceSlug={spaceSlug}
-        editable={editable}
-      />
-      <PageByline
-        pageId={pageId}
-        creator={creator}
-        contributors={contributors}
-        editable={editable}
-        isEditMode={isEditMode}
-        isDictationEnabled={isDictationEnabled}
-        isTitleGenEnabled={isTitleGenEnabled}
-      />
-      <MemoizedPageEditor
-        pageId={pageId}
-        editable={editable}
-        content={content}
-        canComment={canComment}
-      />
+      <EditorProvidersContext.Provider
+        value={ydoc && remote ? { ydoc, remote, providersReady } : null}
+      >
+        <MemoizedTitleEditor
+          pageId={pageId}
+          slugId={slugId}
+          title={title}
+          spaceSlug={spaceSlug}
+          editable={editable}
+        />
+        <PageByline
+          pageId={pageId}
+          creator={creator}
+          contributors={contributors}
+          editable={editable}
+          isEditMode={isEditMode}
+          isDictationEnabled={isDictationEnabled}
+          isTitleGenEnabled={isTitleGenEnabled}
+        />
+        <MemoizedPageEditor
+          pageId={pageId}
+          editable={editable}
+          content={content}
+          canComment={canComment}
+        />
+      </EditorProvidersContext.Provider>
     </Container>
   );
 }

apps/client/src/features/editor/hooks/collab-token.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// jwt-decode is mocked so we can drive the four token states deterministically
+// (decode success with a chosen exp, or a thrown decode error).
+const decodeMock = vi.hoisted(() => vi.fn());
+vi.mock("jwt-decode", () => ({
+  jwtDecode: decodeMock,
+}));
+
+import { collabTokenNeedsRefresh } from "./collab-token";
+
+const NOW_MS = 1_000_000_000; // fixed "now" in ms (so NOW_MS/1000 seconds)
+
+beforeEach(() => {
+  decodeMock.mockReset();
+});
+
+describe("collabTokenNeedsRefresh", () => {
+  it("returns true when there is no token (fetch a fresh one)", () => {
+    expect(collabTokenNeedsRefresh(undefined, NOW_MS)).toBe(true);
+    // jwtDecode must not even be called for a missing token.
+    expect(decodeMock).not.toHaveBeenCalled();
+  });
+
+  it("returns true when the token is malformed (jwtDecode throws)", () => {
+    decodeMock.mockImplementation(() => {
+      throw new Error("invalid token");
+    });
+    expect(collabTokenNeedsRefresh("garbage", NOW_MS)).toBe(true);
+  });
+
+  it("returns false for a valid, not-yet-expired token (no reconnect)", () => {
+    // exp is in the future relative to NOW.
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 + 60 });
+    expect(collabTokenNeedsRefresh("good", NOW_MS)).toBe(false);
+  });
+
+  it("returns true for a valid but expired token (refresh + reconnect)", () => {
+    // exp is in the past relative to NOW.
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 - 60 });
+    expect(collabTokenNeedsRefresh("expired", NOW_MS)).toBe(true);
+  });
+
+  it("treats exp exactly equal to now as expired (>= boundary)", () => {
+    decodeMock.mockReturnValue({ exp: NOW_MS / 1000 });
+    expect(collabTokenNeedsRefresh("boundary", NOW_MS)).toBe(true);
+  });
+});

apps/client/src/features/editor/hooks/collab-token.ts

@@ -0,0 +1,26 @@
+import { jwtDecode } from "jwt-decode";
+
+/**
+ * Decide whether a collab token must be refreshed before reconnecting after an
+ * onAuthenticationFailed event. Pure and side-effect free so the four token
+ * states can be unit-tested directly:
+ *   - no token              -> true  (fetch a fresh one and reconnect)
+ *   - undecodable/malformed -> true  (jwtDecode throws -> refresh)
+ *   - valid, not expired    -> false (token is still good; do NOT reconnect)
+ *   - valid, expired        -> true  (refresh + reconnect)
+ *
+ * `nowMs` is injectable for deterministic tests; it defaults to `Date.now()`.
+ */
+export function collabTokenNeedsRefresh(
+  token: string | undefined,
+  nowMs: number = Date.now(),
+): boolean {
+  if (!token) return true;
+  try {
+    const payload = jwtDecode<{ exp: number }>(token);
+    return nowMs / 1000 >= payload.exp;
+  } catch {
+    // malformed/undecodable token -> refresh
+    return true;
+  }
+}

apps/client/src/features/editor/hooks/use-generate-page-title.test.tsx

@@ -139,7 +139,7 @@ describe("useGeneratePageTitle", () => {
     );
   });
 
-  it("happy path: applies the title, refreshes cache, writes the field, broadcasts", async () => {
+  it("happy path: applies the title, refreshes cache, broadcasts, and does NOT write the editor", async () => {
     const store = createStore();
     const titleEditor = makeTitleEditor();
     store.set(pageEditorAtom as never, makePageEditor("pageA"));
@@ -157,9 +157,11 @@ describe("useGeneratePageTitle", () => {
       title: "Generated Title",
     });
     expect(updatePageDataMock).toHaveBeenCalledWith(PAGE_A);
-    expect(titleEditor.commands.setContent).toHaveBeenCalledWith(
-      "Generated Title",
-    );
+    // The title editor is bound to the Yjs `title` fragment; the server REST
+    // update reseeds that fragment and the reseed reaches the bound editor on
+    // its own. Writing here too would double/garble the title, so the hook must
+    // NOT touch the editor (regression guard for the Yjs duplication trap).
+    expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
     expect(localEmitMock).toHaveBeenCalled();
     expect(emitMock).toHaveBeenCalled();
     expect(notificationsShowMock).toHaveBeenCalledWith(
@@ -167,7 +169,7 @@ describe("useGeneratePageTitle", () => {
     );
   });
 
-  it("does NOT write the visible title field when the user navigated away during generation", async () => {
+  it("keeps the DB write keyed by the captured pageId and still broadcasts after navigation", async () => {
     const store = createStore();
     const titleEditor = makeTitleEditor(); // persistent across navigation
     store.set(pageEditorAtom as never, makePageEditor("pageA"));
@@ -203,55 +205,9 @@ describe("useGeneratePageTitle", () => {
       pageId: "pageA",
       title: "Generated Title",
     });
-    // ...but we must NOT stamp page A's title into page B's visible field.
+    // ...the hook never writes the editor regardless of navigation...
     expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
-    // The change is still broadcast to other clients.
-    expect(emitMock).toHaveBeenCalled();
-  });
-
-  it("does NOT write the visible title field when the title editor is focused", async () => {
-    const store = createStore();
-    const titleEditor = makeTitleEditor();
-    store.set(pageEditorAtom as never, makePageEditor("pageA"));
-    store.set(titleEditorAtom as never, titleEditor);
-
-    // Resolve generation under our control so we can mark the live title editor
-    // as focused before the post-generation write runs.
-    let resolveTitle!: (t: string) => void;
-    generatePageTitleMock.mockReturnValue(
-      new Promise<string>((res) => {
-        resolveTitle = res;
-      }),
-    );
-    updateTitleMock.mockResolvedValue(PAGE_A);
-    const { result } = setup("pageA", store);
-
-    let pending!: Promise<void>;
-    act(() => {
-      pending = result.current.mutateAsync();
-    });
-
-    // The user clicked into the title field while the model ran — overwriting it
-    // now would clobber what they are actively typing.
-    act(() => {
-      (titleEditor as { isFocused: boolean }).isFocused = true;
-    });
-
-    await act(async () => {
-      resolveTitle("Generated Title");
-      await pending;
-    });
-
-    // The DB write still persists the value...
-    expect(updateTitleMock).toHaveBeenCalledWith({
-      pageId: "pageA",
-      title: "Generated Title",
-    });
-    expect(updatePageDataMock).toHaveBeenCalledWith(PAGE_A);
-    // ...but the visible field is left alone while it is focused.
-    expect(titleEditor.commands.setContent).not.toHaveBeenCalled();
-    // The change is still broadcast to other clients.
-    expect(localEmitMock).toHaveBeenCalled();
+    // ...and the change is still broadcast to other clients.
     expect(emitMock).toHaveBeenCalled();
   });
 

apps/client/src/features/editor/hooks/use-generate-page-title.ts

@@ -1,13 +1,9 @@
-import { useRef } from "react";
 import { useMutation } from "@tanstack/react-query";
 import { useAtomValue } from "jotai";
 import { notifications } from "@mantine/notifications";
 import { useTranslation } from "react-i18next";
 import { htmlToMarkdown } from "@docmost/editor-ext";
-import {
-  pageEditorAtom,
-  titleEditorAtom,
-} from "@/features/editor/atoms/editor-atoms.ts";
+import { pageEditorAtom } from "@/features/editor/atoms/editor-atoms.ts";
 import {
   updatePageData,
   useUpdateTitlePageMutation,
@@ -33,18 +29,9 @@ const MAX_CONTENT_CHARS = 20000;
 export function useGeneratePageTitle(pageId: string) {
   const { t } = useTranslation();
   const pageEditor = useAtomValue(pageEditorAtom);
-  const titleEditor = useAtomValue(titleEditorAtom);
   const { mutateAsync: updateTitle } = useUpdateTitlePageMutation();
   const emit = useQueryEmit();
 
-  // The page/title editors come from GLOBAL atoms that re-point when the user
-  // navigates to another page. The mutation below awaits the model for 1-3s, and
-  // its closure captures the editors from the render that started it. Keep a live
-  // reference so the post-generation write targets whatever page is on screen
-  // *now*, not the page the generation was started from.
-  const editorsRef = useRef({ pageEditor, titleEditor });
-  editorsRef.current = { pageEditor, titleEditor };
-
   return useMutation<void, Error, void>({
     mutationFn: async () => {
       if (!pageEditor || pageEditor.isDestroyed) return;
@@ -70,33 +57,15 @@ export function useGeneratePageTitle(pageId: string) {
       const page = await updateTitle({ pageId, title }); // POST /pages/update
       updatePageData(page); // refresh the react-query cache
 
-      // Reflect the new title in the field immediately. The button lives in the
-      // byline, so the title editor is not focused — setContent is safe and stays
-      // undoable through its History extension (Ctrl/Cmd+Z reverts the change).
-      //
-      // Guard against navigation during generation: if the user switched pages
-      // while the model ran, the (persistent) title editor now shows ANOTHER
-      // page, so writing here would drop page A's title into page B's visible
-      // field. page-editor.tsx stamps the live page editor with its pageId
-      // (`editor.storage.pageId`), mirroring TitleEditor's `activePageId !==
-      // pageId` guard — bail the visible write unless that live editor still
-      // belongs to the page this title was generated for. The DB write above is
-      // already correct (keyed by the captured `pageId`), and the broadcast below
-      // still propagates page A's change to other clients.
-      const livePageEditor = editorsRef.current.pageEditor;
-      const liveTitleEditor = editorsRef.current.titleEditor;
-      // `storage.pageId` is stamped untyped in page-editor.tsx's onCreate.
-      const livePageId = (livePageEditor?.storage as { pageId?: string })
-        ?.pageId;
-      const stillOnPage = livePageId === pageId;
-      if (
-        stillOnPage &&
-        liveTitleEditor &&
-        !liveTitleEditor.isDestroyed &&
-        !liveTitleEditor.isFocused
-      ) {
-        liveTitleEditor.commands.setContent(page.title);
-      }
+      // Do NOT write the title into the editor here. The title editor is bound to
+      // the Yjs `title` fragment and Yjs is the source of truth. The server REST
+      // /pages/update reseeds that fragment (writePageTitle → writeTitleFragment,
+      // a full clear+replace) and the reseed reaches the bound title editor on
+      // its own as a remote provider update. The old REST-era setContent here
+      // would race that reseed and double/garble the title (the "Yjs duplication
+      // trap"), so it is intentionally omitted. The DB write above is keyed by
+      // the captured `pageId`, so it stays correct even if the user navigated
+      // away during generation.
 
       // Broadcast to other clients, mirroring TitleEditor.saveTitle's event shape.
       const event: UpdateEvent = {

apps/client/src/features/editor/hooks/use-page-collab-providers.ts

@@ -0,0 +1,189 @@
+import { useEffect, useRef, useState } from "react";
+import { IndexeddbPersistence } from "y-indexeddb";
+import * as Y from "yjs";
+import {
+  HocuspocusProvider,
+  onStatusParameters,
+  WebSocketStatus,
+  HocuspocusProviderWebsocket,
+  onSyncedParameters,
+  onStatelessParameters,
+} from "@hocuspocus/provider";
+import { useAtom, useSetAtom } from "jotai";
+import useCollaborationUrl from "@/features/editor/hooks/use-collaboration-url";
+import {
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
+  yjsConnectionStatusAtom,
+} from "@/features/editor/atoms/editor-atoms";
+import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
+import { useDocumentVisibility } from "@mantine/hooks";
+import { useIdle } from "@/hooks/use-idle.ts";
+import { queryClient } from "@/main.tsx";
+import { IPage } from "@/features/page/types/page.types.ts";
+import { useParams } from "react-router-dom";
+import { extractPageSlugId } from "@/lib";
+import { FIVE_MINUTES } from "@/lib/constants.ts";
+import { collabTokenNeedsRefresh } from "@/features/editor/hooks/collab-token";
+import { pageYdocName } from "@/features/editor/page-ydoc-name";
+import { pageKeys } from "@/features/page/queries/page-query";
+
+export interface PageCollabProviders {
+  ydoc: Y.Doc | null;
+  remote: HocuspocusProvider | null;
+  socket: HocuspocusProviderWebsocket | null;
+  providersReady: boolean;
+}
+
+/**
+ * Owns the full collaboration provider lifecycle for a page so that the title
+ * and body editors can share a single Y.Doc + HocuspocusProvider. The behavior
+ * is relocated verbatim from page-editor.tsx: it creates the providers once per
+ * pageId, connects/disconnects on idle/visibility, attaches each render,
+ * destroys on unmount, refreshes the collab token on auth failure, and applies
+ * the onStateless 'page.updated' cache update.
+ */
+export function usePageCollabProviders(pageId: string): PageCollabProviders {
+  const collaborationURL = useCollaborationUrl();
+  const [yjsConnectionStatus, setYjsConnectionStatus] = useAtom(
+    yjsConnectionStatusAtom,
+  );
+  const setIsLocalSyncedAtom = useSetAtom(isLocalSyncedAtom);
+  const setIsRemoteSyncedAtom = useSetAtom(isRemoteSyncedAtom);
+  const { data: collabQuery, refetch: refetchCollabToken } = useCollabToken();
+  // The provider-creating effect runs only once per pageId, so any token read
+  // inside its handlers would be captured STALE (the old token at first render).
+  // Mirror the latest token into a ref the auth-failure handler can read live.
+  const collabTokenRef = useRef<string | undefined>(undefined);
+  useEffect(() => {
+    collabTokenRef.current = collabQuery?.token;
+  }, [collabQuery?.token]);
+  const { isIdle, resetIdle } = useIdle(FIVE_MINUTES, { initialState: false });
+  const documentState = useDocumentVisibility();
+  const { pageSlug } = useParams();
+  const slugId = extractPageSlugId(pageSlug);
+
+  // Providers only created once per pageId
+  const providersRef = useRef<{
+    ydoc: Y.Doc;
+    local: IndexeddbPersistence;
+    remote: HocuspocusProvider;
+    socket: HocuspocusProviderWebsocket;
+  } | null>(null);
+  const [providersReady, setProvidersReady] = useState(false);
+
+  useEffect(() => {
+    if (!providersRef.current) {
+      const documentName = pageYdocName(pageId);
+      const ydoc = new Y.Doc();
+      const local = new IndexeddbPersistence(documentName, ydoc);
+      const socket = new HocuspocusProviderWebsocket({
+        url: collaborationURL,
+      });
+      const onLocalSyncedHandler = () => {
+        setIsLocalSyncedAtom(true);
+      };
+      const onStatusHandler = (event: onStatusParameters) => {
+        setYjsConnectionStatus(event.status);
+      };
+      const onSyncedHandler = (event: onSyncedParameters) => {
+        setIsRemoteSyncedAtom(event.state);
+      };
+      const onStatelessHandler = ({ payload }: onStatelessParameters) => {
+        try {
+          const message = JSON.parse(payload);
+          if (message?.type !== "page.updated" || !message.updatedAt) return;
+          const pageData = queryClient.getQueryData<IPage>(
+            pageKeys.detail(slugId),
+          );
+          if (pageData) {
+            queryClient.setQueryData(pageKeys.detail(slugId), {
+              ...pageData,
+              updatedAt: message.updatedAt,
+              ...(message.lastUpdatedBy && {
+                lastUpdatedBy: message.lastUpdatedBy,
+              }),
+            });
+          }
+        } catch {
+          // ignore unrelated stateless messages
+        }
+      };
+      const onAuthenticationFailedHandler = () => {
+        // Read the token from the ref, not the closed-over `collabQuery`: this
+        // handler is created once and would otherwise decode a stale token after
+        // a refetch. A missing/malformed token must NOT crash the handler —
+        // jwtDecode(undefined) throws — so treat any decode failure as "needs
+        // refresh" and proceed to refetch + reconnect instead of getting stuck.
+        if (!collabTokenNeedsRefresh(collabTokenRef.current)) return;
+        refetchCollabToken().then((result) => {
+          if (result.data?.token) {
+            socket.disconnect();
+            setTimeout(() => {
+              remote.configuration.token = result.data.token;
+              socket.connect();
+            }, 100);
+          }
+        });
+      };
+      const remote = new HocuspocusProvider({
+        websocketProvider: socket,
+        name: documentName,
+        document: ydoc,
+        token: collabQuery?.token,
+        onAuthenticationFailed: onAuthenticationFailedHandler,
+        onStatus: onStatusHandler,
+        onSynced: onSyncedHandler,
+        onStateless: onStatelessHandler,
+      });
+
+      local.on("synced", onLocalSyncedHandler);
+      providersRef.current = { ydoc, socket, local, remote };
+      setProvidersReady(true);
+    } else {
+      setProvidersReady(true);
+    }
+    // Only destroy on final unmount
+    return () => {
+      providersRef.current?.socket.destroy();
+      providersRef.current?.remote.destroy();
+      providersRef.current?.local.destroy();
+      providersRef.current = null;
+      // Reset shared sync state on page change/unmount.
+      setIsLocalSyncedAtom(false);
+      setIsRemoteSyncedAtom(false);
+    };
+  }, [pageId]);
+
+  // Only connect/disconnect on tab/idle, not destroy
+  useEffect(() => {
+    if (!providersReady || !providersRef.current) return;
+    const socket = providersRef.current.socket;
+
+    if (
+      isIdle &&
+      documentState === "hidden" &&
+      yjsConnectionStatus === WebSocketStatus.Connected
+    ) {
+      socket.disconnect();
+      return;
+    }
+    if (
+      documentState === "visible" &&
+      yjsConnectionStatus === WebSocketStatus.Disconnected
+    ) {
+      resetIdle();
+      socket.connect();
+    }
+  }, [isIdle, documentState, providersReady, resetIdle]);
+
+  // Attach here, to make sure the connection gets properly established
+  providersRef.current?.remote.attach();
+
+  return {
+    ydoc: providersRef.current?.ydoc ?? null,
+    remote: providersRef.current?.remote ?? null,
+    socket: providersRef.current?.socket ?? null,
+    providersReady,
+  };
+}

apps/client/src/features/editor/page-editor.tsx

@@ -6,16 +6,7 @@ import React, {
   useRef,
   useState,
 } from "react";
-import { IndexeddbPersistence } from "y-indexeddb";
-import * as Y from "yjs";
-import {
-  HocuspocusProvider,
-  onStatusParameters,
-  WebSocketStatus,
-  HocuspocusProviderWebsocket,
-  onSyncedParameters,
-  onStatelessParameters,
-} from "@hocuspocus/provider";
+import { WebSocketStatus } from "@hocuspocus/provider";
 import {
   Editor,
   EditorContent,
@@ -28,13 +19,15 @@ import {
   mainExtensions,
 } from "@/features/editor/extensions/extensions";
 import { useAtom, useAtomValue } from "jotai";
-import useCollaborationUrl from "@/features/editor/hooks/use-collaboration-url";
 import { currentUserAtom } from "@/features/user/atoms/current-user-atom";
 import {
   currentPageEditModeAtom,
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms";
+import { useEditorProviders } from "@/features/editor/contexts/editor-providers-context";
 import { asideStateAtom } from "@/components/layouts/global/hooks/atoms/sidebar-atom";
 import {
   activeCommentIdAtom,
@@ -58,10 +51,8 @@ import {
 } from "@/features/editor/components/common/editor-paste-handler.tsx";
 import ExcalidrawMenu from "./components/excalidraw/excalidraw-menu-lazy";
 import DrawioMenu from "./components/drawio/drawio-menu";
-import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import SearchAndReplaceDialog from "@/features/editor/components/search-and-replace/search-and-replace-dialog.tsx";
-import { useDebouncedCallback, useDocumentVisibility } from "@mantine/hooks";
-import { useIdle } from "@/hooks/use-idle.ts";
+import { useDebouncedCallback } from "@mantine/hooks";
 import { queryClient } from "@/main.tsx";
 import { IPage } from "@/features/page/types/page.types.ts";
 import { useParams } from "react-router-dom";
@@ -72,9 +63,7 @@ import {
   GitmostInsertRecordingResult,
   gitmostInsertRecordingIntoEditor,
 } from "@/features/editor/gitmost/gitmost-recording.ts";
-import { FIVE_MINUTES } from "@/lib/constants.ts";
 import { PageEditMode } from "@/features/user/types/user.types.ts";
-import { jwtDecode } from "jwt-decode";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { useEditorScroll } from "./hooks/use-editor-scroll";
 import { EditorLinkMenu } from "@/features/editor/components/link/link-menu";
@@ -103,7 +92,6 @@ export default function PageEditor({
   canComment,
 }: PageEditorProps) {
   const { t } = useTranslation();
-  const collaborationURL = useCollaborationUrl();
   const isComponentMounted = useRef(false);
   const editorRef = useRef<Editor | null>(null);
 
@@ -117,22 +105,10 @@ export default function PageEditor({
   const [, setActiveCommentId] = useAtom(activeCommentIdAtom);
   const [showCommentPopup, setShowCommentPopup] = useAtom(showCommentPopupAtom);
   const [showReadOnlyCommentPopup] = useAtom(showReadOnlyCommentPopupAtom);
-  const [isLocalSynced, setIsLocalSynced] = useState(false);
-  const [isRemoteSynced, setIsRemoteSynced] = useState(false);
   const [yjsConnectionStatus, setYjsConnectionStatus] = useAtom(
     yjsConnectionStatusAtom,
   );
   const menuContainerRef = useRef(null);
-  const { data: collabQuery, refetch: refetchCollabToken } = useCollabToken();
-  // Always holds the latest collab token. The provider effect below runs once
-  // per pageId, so a handler created inside it would otherwise close over a
-  // stale `collabQuery`. Reading the ref gives the current token instead.
-  const collabTokenRef = useRef<string | undefined>(undefined);
-  useEffect(() => {
-    collabTokenRef.current = collabQuery?.token;
-  }, [collabQuery?.token]);
-  const { isIdle, resetIdle } = useIdle(FIVE_MINUTES, { initialState: false });
-  const documentState = useDocumentVisibility();
   const { pageSlug } = useParams();
   const slugId = extractPageSlugId(pageSlug);
   const currentPageEditMode = useAtomValue(currentPageEditModeAtom);
@@ -141,141 +117,27 @@ export default function PageEditor({
     [isComponentMounted],
   );
   const { handleScrollTo } = useEditorScroll({ canScroll });
-  // Providers only created once per pageId
-  const providersRef = useRef<{
-    local: IndexeddbPersistence;
-    remote: HocuspocusProvider;
-    socket: HocuspocusProviderWebsocket;
-  } | null>(null);
-  const [providersReady, setProvidersReady] = useState(false);
 
-  useEffect(() => {
-    if (!providersRef.current) {
-      const documentName = `page.${pageId}`;
-      const ydoc = new Y.Doc();
-      const local = new IndexeddbPersistence(documentName, ydoc);
-      const socket = new HocuspocusProviderWebsocket({
-        url: collaborationURL,
-      });
-      const onLocalSyncedHandler = () => {
-        setIsLocalSynced(true);
-      };
-      const onStatusHandler = (event: onStatusParameters) => {
-        setYjsConnectionStatus(event.status);
-      };
-      const onSyncedHandler = (event: onSyncedParameters) => {
-        setIsRemoteSynced(event.state);
-      };
-      const onStatelessHandler = ({ payload }: onStatelessParameters) => {
-        try {
-          const message = JSON.parse(payload);
-          if (message?.type !== "page.updated" || !message.updatedAt) return;
-          const pageData = queryClient.getQueryData<IPage>(["pages", slugId]);
-          if (pageData) {
-            queryClient.setQueryData(["pages", slugId], {
-              ...pageData,
-              updatedAt: message.updatedAt,
-              ...(message.lastUpdatedBy && {
-                lastUpdatedBy: message.lastUpdatedBy,
-              }),
-            });
-          }
-        } catch {
-          // ignore unrelated stateless messages
-        }
-      };
-      const onAuthenticationFailedHandler = () => {
-        // Read the latest token via the ref (the closure-captured `collabQuery`
-        // may be stale). Guard the decode: a missing or unparseable token must
-        // not throw "Invalid token specified" and should trigger a refresh so
-        // the editor reconnects even when the initial token fetch failed.
-        const token = collabTokenRef.current;
-        let needsRefresh = true; // no/unparseable token -> fetch a fresh one and reconnect
-        if (token) {
-          try {
-            // A token that decodes but lacks a numeric `exp` must be treated as
-            // expired (`Date.now()/1000 >= undefined` is `false`, which would
-            // otherwise skip the reconnect), so refresh on any missing/non-number exp.
-            const exp = jwtDecode<{ exp?: number }>(token).exp;
-            needsRefresh = typeof exp !== "number" || Date.now() / 1000 >= exp;
-          } catch {
-            needsRefresh = true;
-          }
-        }
-        if (!needsRefresh) return;
-        refetchCollabToken().then((result) => {
-          if (result.data?.token) {
-            socket.disconnect();
-            setTimeout(() => {
-              remote.configuration.token = result.data.token;
-              socket.connect();
-            }, 100);
-          }
-        });
-      };
-      const remote = new HocuspocusProvider({
-        websocketProvider: socket,
-        name: documentName,
-        document: ydoc,
-        token: collabQuery?.token,
-        onAuthenticationFailed: onAuthenticationFailedHandler,
-        onStatus: onStatusHandler,
-        onSynced: onSyncedHandler,
-        onStateless: onStatelessHandler,
-      });
-
-      local.on("synced", onLocalSyncedHandler);
-      providersRef.current = { socket, local, remote };
-      setProvidersReady(true);
-    } else {
-      setProvidersReady(true);
-    }
-    // Only destroy on final unmount
-    return () => {
-      providersRef.current?.socket.destroy();
-      providersRef.current?.remote.destroy();
-      providersRef.current?.local.destroy();
-      providersRef.current = null;
-    };
-  }, [pageId]);
-
-  // Only connect/disconnect on tab/idle, not destroy
-  useEffect(() => {
-    if (!providersReady || !providersRef.current) return;
-    const socket = providersRef.current.socket;
-
-    if (
-      isIdle &&
-      documentState === "hidden" &&
-      yjsConnectionStatus === WebSocketStatus.Connected
-    ) {
-      socket.disconnect();
-      return;
-    }
-    if (
-      documentState === "visible" &&
-      yjsConnectionStatus === WebSocketStatus.Disconnected
-    ) {
-      resetIdle();
-      socket.connect();
-    }
-  }, [isIdle, documentState, providersReady, resetIdle]);
-
-  // Attach here, to make sure the connection gets properly established
-  providersRef.current?.remote.attach();
+  // Shared providers + Y.Doc lifted into full-editor via context. The provider
+  // lifecycle (creation, idle/visibility connect, attach, destroy, token
+  // refresh) lives in usePageCollabProviders. Null-safe when rendered without
+  // the context (defensive) — in practice full-editor always provides it.
+  const editorProviders = useEditorProviders();
+  const remote = editorProviders?.remote ?? null;
+  const providersReady = editorProviders?.providersReady ?? false;
+  const isLocalSynced = useAtomValue(isLocalSyncedAtom);
+  const isRemoteSynced = useAtomValue(isRemoteSyncedAtom);
 
   const extensions = useMemo(() => {
-    if (!providersReady || !providersRef.current || !currentUser?.user) {
+    if (!providersReady || !remote || !currentUser?.user) {
       return mainExtensions;
     }
 
-    const remoteProvider = providersRef.current.remote;
-
     return [
       ...mainExtensions,
-      ...collabExtensions(remoteProvider, currentUser?.user),
+      ...collabExtensions(remote, currentUser?.user),
     ];
-  }, [providersReady, currentUser?.user]);
+  }, [providersReady, remote, currentUser?.user]);
 
   const editor = useEditor(
     {
@@ -550,7 +412,7 @@ export default function PageEditor({
             {editor &&
               !editorIsEditable &&
               (editable || canComment) &&
-              providersRef.current && <ReadonlyBubbleMenu editor={editor} />}
+              remote && <ReadonlyBubbleMenu editor={editor} />}
             {showCommentPopup && (
               <CommentDialog editor={editor} pageId={pageId} />
             )}

apps/client/src/features/editor/page-ydoc-name.ts

@@ -0,0 +1,14 @@
+/**
+ * Single source of truth for the IndexedDB / Hocuspocus document name of a
+ * page's collaborative Yjs doc.
+ *
+ * The `page.<id>` convention is shared knowledge across three call sites: the
+ * live editor providers (`use-page-collab-providers`), the offline warm path
+ * (`make-offline`), and the offline purge (`clear-offline-cache`, which matches
+ * the databases to delete by this prefix). Centralizing it here stops those
+ * sites from silently drifting apart.
+ */
+export const PAGE_YDOC_NAME_PREFIX = "page.";
+
+export const pageYdocName = (pageId: string): string =>
+  `${PAGE_YDOC_NAME_PREFIX}${pageId}`;

apps/client/src/features/editor/title-collab.test.ts

@@ -0,0 +1,33 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// isChangeOrigin is mocked so we can simulate local vs remote/collab-origin
+// transactions without constructing a real ProseMirror/Yjs transaction.
+const isChangeOriginMock = vi.hoisted(() => vi.fn());
+vi.mock("@tiptap/extension-collaboration", () => ({
+  isChangeOrigin: isChangeOriginMock,
+}));
+
+import { shouldPropagateTitleChange } from "./title-collab";
+
+beforeEach(() => {
+  isChangeOriginMock.mockReset();
+});
+
+describe("shouldPropagateTitleChange", () => {
+  it("propagates a genuine local edit (isChangeOrigin false)", () => {
+    isChangeOriginMock.mockReturnValue(false);
+    expect(shouldPropagateTitleChange({ local: true })).toBe(true);
+    expect(isChangeOriginMock).toHaveBeenCalledWith({ local: true });
+  });
+
+  it("skips a remote/collab-origin update (isChangeOrigin true)", () => {
+    isChangeOriginMock.mockReturnValue(true);
+    expect(shouldPropagateTitleChange({ remote: true })).toBe(false);
+  });
+
+  it("propagates when there is no transaction (treated as local)", () => {
+    expect(shouldPropagateTitleChange(undefined)).toBe(true);
+    // isChangeOrigin must not be called for a missing transaction.
+    expect(isChangeOriginMock).not.toHaveBeenCalled();
+  });
+});

apps/client/src/features/editor/title-collab.ts

@@ -0,0 +1,19 @@
+import { isChangeOrigin } from "@tiptap/extension-collaboration";
+
+/**
+ * Whether a TitleEditor `onUpdate` should drive URL + tree propagation.
+ *
+ * Only genuine LOCAL edits propagate. Remote/collab-origin Yjs updates
+ * (detected via `isChangeOrigin`) are skipped so a remote title change is not
+ * re-broadcast back, which would create a feedback loop. A missing transaction
+ * is treated as a local edit (propagate).
+ *
+ * Extracted as a pure helper so the skip decision is unit-testable without
+ * mounting the full collaborative editor.
+ */
+export function shouldPropagateTitleChange(transaction: unknown): boolean {
+  return !(
+    transaction &&
+    isChangeOrigin(transaction as Parameters<typeof isChangeOrigin>[0])
+  );
+}

apps/client/src/features/editor/title-editor.test.tsx

@@ -0,0 +1,87 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen } from "@testing-library/react";
+
+// Drive the fallback-vs-collaborative switch (titleReady = providersReady &&
+// !!ydoc) by controlling what the editor-providers context returns.
+const editorProvidersValue: { ydoc: unknown; providersReady: boolean } = {
+  ydoc: null,
+  providersReady: false,
+};
+vi.mock("@/features/editor/contexts/editor-providers-context", () => ({
+  useEditorProviders: () => editorProvidersValue,
+}));
+
+// Mock the tiptap React bindings so the test does not mount a real editor:
+// useEditor returns a minimal stub and EditorContent renders a marker.
+vi.mock("@tiptap/react", () => ({
+  useEditor: () => ({
+    isInitialized: true,
+    commands: { focus: vi.fn() },
+    setEditable: vi.fn(),
+    getText: () => "",
+  }),
+  EditorContent: () => <div data-testid="collab-editor" />,
+}));
+
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({ t: (k: string) => k }),
+}));
+
+const navigateMock = vi.fn();
+vi.mock("react-router-dom", () => ({
+  useNavigate: () => navigateMock,
+}));
+
+vi.mock("@/features/websocket/use-query-emit.ts", () => ({
+  useQueryEmit: () => vi.fn(),
+}));
+
+// page-query transitively imports @/main.tsx; mock it to a pure stub.
+vi.mock("@/features/page/queries/page-query", () => ({
+  updatePageData: vi.fn(),
+}));
+vi.mock("@/main.tsx", () => ({
+  queryClient: { getQueryData: vi.fn(), setQueryData: vi.fn() },
+}));
+
+import { TitleEditor } from "./title-editor";
+
+const baseProps = {
+  pageId: "p1",
+  slugId: "slug-1",
+  title: "My Page Title",
+  spaceSlug: "space",
+  editable: true,
+};
+
+beforeEach(() => {
+  navigateMock.mockReset();
+  editorProvidersValue.ydoc = null;
+  editorProvidersValue.providersReady = false;
+});
+
+describe("TitleEditor fallback vs collaborative switch", () => {
+  it("renders a static <h1> with the title before the shared doc is ready", () => {
+    editorProvidersValue.ydoc = null;
+    editorProvidersValue.providersReady = false;
+
+    render(<TitleEditor {...baseProps} />);
+
+    const heading = screen.getByRole("heading", { level: 1 });
+    expect(heading.textContent).toBe("My Page Title");
+    // The collaborative editor must NOT mount until the doc is ready.
+    expect(screen.queryByTestId("collab-editor")).toBeNull();
+  });
+
+  it("renders the collaborative editor once the shared doc is ready", () => {
+    editorProvidersValue.ydoc = {}; // truthy shared doc
+    editorProvidersValue.providersReady = true;
+
+    render(<TitleEditor {...baseProps} />);
+
+    expect(screen.getByTestId("collab-editor")).toBeDefined();
+    // The static fallback <h1> is gone — Yjs is the single source of truth and
+    // the prop is never seeded into the collaborative editor.
+    expect(screen.queryByRole("heading", { level: 1 })).toBeNull();
+  });
+});

apps/client/src/features/editor/title-editor.tsx

@@ -1,5 +1,5 @@
 import "@/features/editor/styles/index.css";
-import React, { useCallback, useEffect, useState } from "react";
+import { useEffect } from "react";
 import { EditorContent, useEditor } from "@tiptap/react";
 import { Document } from "@tiptap/extension-document";
 import { Heading } from "@tiptap/extension-heading";
@@ -11,14 +11,11 @@ import {
   pageEditorAtom,
   titleEditorAtom,
 } from "@/features/editor/atoms/editor-atoms";
-import {
-  updatePageData,
-  useUpdateTitlePageMutation,
-} from "@/features/page/queries/page-query";
+import { pageKeys, updatePageData } from "@/features/page/queries/page-query";
 import { useDebouncedCallback, getHotkeyHandler } from "@mantine/hooks";
 import { useAtom } from "jotai";
-import { useQueryEmit } from "@/features/websocket/use-query-emit.ts";
-import { History } from "@tiptap/extension-history";
+import { Collaboration } from "@tiptap/extension-collaboration";
+import { shouldPropagateTitleChange } from "@/features/editor/title-collab";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
 import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18next";
@@ -28,6 +25,9 @@ import localEmitter from "@/lib/local-emitter.ts";
 import { PageEditMode } from "@/features/user/types/user.types.ts";
 import { searchSpotlight } from "@/features/search/constants.ts";
 import { platformModifierKey } from "@/lib";
+import { useEditorProviders } from "@/features/editor/contexts/editor-providers-context";
+import { queryClient } from "@/main.tsx";
+import { IPage } from "@/features/page/types/page.types.ts";
 
 export interface TitleEditorProps {
   pageId: string;
@@ -45,65 +45,82 @@ export function TitleEditor({
   editable,
 }: TitleEditorProps) {
   const { t } = useTranslation();
-  const { mutateAsync: updateTitlePageMutationAsync } =
-    useUpdateTitlePageMutation();
   const pageEditor = useAtomValue(pageEditorAtom);
   const [, setTitleEditor] = useAtom(titleEditorAtom);
-  const emit = useQueryEmit();
   const navigate = useNavigate();
-  const [activePageId, setActivePageId] = useState(pageId);
   const currentPageEditMode = useAtomValue(currentPageEditModeAtom);
 
-  const titleEditor = useEditor({
-    extensions: [
-      Document.extend({
-        content: "heading",
-      }),
-      Heading.configure({
-        levels: [1],
-      }),
-      Text,
-      Placeholder.configure({
-        placeholder: t("Untitled"),
-        showOnlyWhenEditable: false,
-      }),
-      History.configure({
-        depth: 20,
-      }),
-      EmojiCommand,
-    ],
-    onCreate({ editor }) {
-      if (editor) {
-        // @ts-ignore
-        setTitleEditor(editor);
-        setActivePageId(pageId);
-      }
-    },
-    onUpdate({ editor }) {
-      debounceUpdate();
-    },
-    editable: editable,
-    content: title,
-    immediatelyRender: true,
-    shouldRerenderOnTransaction: false,
-    editorProps: {
-      attributes: {
-        "aria-label": t("Page title"),
+  // Shared Y.Doc (title lives in its own 'title' fragment of the same doc as
+  // the body). Yjs is the source of truth for the title content.
+  const editorProviders = useEditorProviders();
+  const ydoc = editorProviders?.ydoc ?? null;
+  const providersReady = editorProviders?.providersReady ?? false;
+
+  // Until the shared doc is ready, the collaborative editor binds nothing and
+  // would render an empty heading until the Yjs 'title' fragment hydrates. Show
+  // a non-editable static <h1> with the `title` prop in the meantime. The prop
+  // is NEVER fed into the collaborative editor (Yjs stays the single source of
+  // truth — seeding it would duplicate the title).
+  const titleReady = providersReady && !!ydoc;
+
+  const titleEditor = useEditor(
+    {
+      extensions: [
+        Document.extend({
+          content: "heading",
+        }),
+        Heading.configure({
+          levels: [1],
+        }),
+        Text,
+        Placeholder.configure({
+          placeholder: t("Untitled"),
+          showOnlyWhenEditable: false,
+        }),
+        // Bind the title to the dedicated 'title' fragment of the shared doc.
+        // Collaboration also manages undo/redo, so the History extension is
+        // intentionally omitted (it would conflict with Yjs). When the doc is
+        // not ready yet the editor renders empty until the doc arrives.
+        ...(ydoc
+          ? [Collaboration.configure({ document: ydoc, field: "title" })]
+          : []),
+        EmojiCommand,
+      ],
+      onCreate({ editor }) {
+        if (editor) {
+          // @ts-ignore
+          setTitleEditor(editor);
+        }
       },
-      handleDOMEvents: {
-        keydown: (_view, event) => {
-          if (platformModifierKey(event) && event.code === "KeyS") {
-            event.preventDefault();
-            return true;
-          }
-          if (platformModifierKey(event) && event.code === "KeyK") {
-            searchSpotlight.open();
-            return true;
-          }
+      onUpdate({ editor, transaction }) {
+        // Drive URL + tree propagation only on genuine local edits; skip
+        // remote/collab-origin Yjs updates to avoid feedback loops.
+        if (!shouldPropagateTitleChange(transaction)) return;
+        debouncedPropagateTitle(editor.getText());
+      },
+      editable: editable,
+      immediatelyRender: true,
+      shouldRerenderOnTransaction: false,
+      editorProps: {
+        attributes: {
+          "aria-label": t("Page title"),
+        },
+        handleDOMEvents: {
+          keydown: (_view, event) => {
+            if (platformModifierKey(event) && event.code === "KeyS") {
+              event.preventDefault();
+              return true;
+            }
+            if (platformModifierKey(event) && event.code === "KeyK") {
+              searchSpotlight.open();
+              return true;
+            }
+          },
         },
       },
     },
-  });
+    [pageId, ydoc],
+  );
 
   useEffect(() => {
     const anchorId = window.location.hash
@@ -113,59 +130,45 @@ export function TitleEditor({
     navigate(pageSlug, { replace: true });
   }, [title]);
 
-  const saveTitle = useCallback(() => {
-    if (!titleEditor || activePageId !== pageId) return;
-
-    if (
-      titleEditor.getText() === title ||
-      (titleEditor.getText() === "" && title === null)
-    ) {
-      return;
-    }
-
-    updateTitlePageMutationAsync({
-      pageId: pageId,
-      title: titleEditor.getText(),
-    }).then((page) => {
-      const event: UpdateEvent = {
-        operation: "updateOne",
-        spaceId: page.spaceId,
-        entity: ["pages"],
-        id: page.id,
-        payload: {
-          title: page.title,
-          slugId: page.slugId,
-          parentPageId: page.parentPageId,
-          icon: page.icon,
-        },
-      };
-
-      if (page.title !== titleEditor.getText()) return;
-
-      updatePageData(page);
-
-      localEmitter.emit("message", event);
-      emit(event);
+  // On a local title change: update the URL slug and propagate the change to
+  // the live tree/breadcrumbs for online users. No REST round-trip — the title
+  // itself is persisted through Yjs. Offline this simply no-ops the socket
+  // emit and the title syncs on reconnect.
+  const debouncedPropagateTitle = useDebouncedCallback((titleText: string) => {
+    const anchorId = window.location.hash
+      ? window.location.hash.substring(1)
+      : undefined;
+    navigate(buildPageUrl(spaceSlug, slugId, titleText, anchorId), {
+      replace: true,
     });
-  }, [pageId, title, titleEditor]);
 
-  const debounceUpdate = useDebouncedCallback(saveTitle, 500);
+    const page =
+      queryClient.getQueryData<IPage>(pageKeys.detail(slugId)) ??
+      queryClient.getQueryData<IPage>(pageKeys.detail(pageId));
+    if (!page) return;
 
-  useEffect(() => {
-    // Do not overwrite the title while the user is actively editing it. The
-    // server rebroadcasts PAGE_UPDATED to the author too, and that echo can
-    // carry a title that lags behind what the user has just typed; resetting
-    // content from it here would drop in-progress characters and jump the
-    // cursor. Apply external title changes only when the field is not focused.
-    if (
-      titleEditor &&
-      !titleEditor.isDestroyed &&
-      !titleEditor.isFocused &&
-      title !== titleEditor.getText()
-    ) {
-      titleEditor.commands.setContent(title);
-    }
-  }, [pageId, title, titleEditor]);
+    const updatedPage: IPage = { ...page, title: titleText };
+
+    const event: UpdateEvent = {
+      operation: "updateOne",
+      spaceId: page.spaceId,
+      entity: ["pages"],
+      id: page.id,
+      payload: {
+        title: titleText,
+        slugId: page.slugId,
+        parentPageId: page.parentPageId,
+        icon: page.icon,
+      },
+    };
+
+    updatePageData(updatedPage);
+    // Drive the local (same-tab) tree/breadcrumb update. The cross-user tree
+    // refresh is handled server-side: the collab process extracts the renamed
+    // 'title' Yjs fragment and broadcasts a treeUpdate. The previous socket
+    // `emit(event)` here was a no-op (the gateway ignores it) and was removed.
+    localEmitter.emit("message", event);
+  }, 500);
 
   useEffect(() => {
     setTimeout(() => {
@@ -175,13 +178,6 @@ export function TitleEditor({
     }, 300);
   }, [titleEditor]);
 
-  useEffect(() => {
-    return () => {
-      // force-save title on navigation
-      saveTitle();
-    };
-  }, [pageId]);
-
   useEffect(() => {
     if (!titleEditor) return;
     titleEditor.setEditable(editable && currentPageEditMode === PageEditMode.Edit);
@@ -248,16 +244,22 @@ export function TitleEditor({
 
   return (
     <div className="page-title">
-      <EditorContent
-        editor={titleEditor}
-        onKeyDown={(event) => {
-          // First handle the search hotkey
-          getHotkeyHandler([["mod+F", openSearchDialog]])(event);
+      {titleReady ? (
+        <EditorContent
+          editor={titleEditor}
+          onKeyDown={(event) => {
+            // First handle the search hotkey
+            getHotkeyHandler([["mod+F", openSearchDialog]])(event);
 
-          // Then handle other key events
-          handleTitleKeyDown(event);
-        }}
-      />
+            // Then handle other key events
+            handleTitleKeyDown(event);
+          }}
+        />
+      ) : (
+        // Static, non-editable fallback so the title is visible before Yjs
+        // hydrates the 'title' fragment. Not wired into the collaborative editor.
+        <h1>{title}</h1>
+      )}
     </div>
   );
 }

apps/client/src/features/offline/clear-offline-cache.test.ts

@@ -0,0 +1,107 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+// vi.mock factories are hoisted above imports, so the spies they reference must
+// be declared via vi.hoisted (also hoisted). These are inspected by assertions.
+const h = vi.hoisted(() => ({
+  clear: vi.fn(),
+  del: vi.fn(),
+}));
+
+// The module under test imports the app entry at load time — it must be mocked.
+vi.mock("@/main.tsx", () => ({
+  queryClient: { clear: h.clear },
+}));
+vi.mock("idb-keyval", () => ({
+  del: h.del,
+}));
+
+import { clearOfflineCache } from "./clear-offline-cache";
+import { OFFLINE_CACHE_KEY } from "./query-persister";
+
+// jsdom does not provide indexedDB.databases() or Cache Storage, so the browser
+// globals are stubbed per-test. We restore them afterwards.
+const originalIndexedDB = (globalThis as any).indexedDB;
+const originalCaches = (globalThis as any).caches;
+
+beforeEach(() => {
+  h.clear.mockClear();
+  h.del.mockClear();
+});
+
+afterEach(() => {
+  (globalThis as any).indexedDB = originalIndexedDB;
+  (globalThis as any).caches = originalCaches;
+  vi.restoreAllMocks();
+});
+
+describe("clearOfflineCache", () => {
+  it("resolves without throwing when the browser globals are absent", async () => {
+    (globalThis as any).indexedDB = undefined;
+    delete (globalThis as any).caches;
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+
+    // The two store-agnostic steps still run.
+    expect(h.clear).toHaveBeenCalledTimes(1);
+    expect(h.del).toHaveBeenCalledWith(OFFLINE_CACHE_KEY);
+  });
+
+  it("deletes only `page.*` IndexedDB databases and only `api-get-cache` caches", async () => {
+    const deleteDatabase = vi.fn((_name: string) => {
+      const request: any = {};
+      // Resolve the deletion on the next microtask, like a real IDBRequest.
+      queueMicrotask(() => request.onsuccess && request.onsuccess());
+      return request;
+    });
+    (globalThis as any).indexedDB = {
+      databases: vi
+        .fn()
+        .mockResolvedValue([
+          { name: "page.aaa" },
+          { name: "page.bbb" },
+          { name: "keyval-store" },
+          { name: undefined },
+        ]),
+      deleteDatabase,
+    };
+
+    const cacheDelete = vi.fn().mockResolvedValue(true);
+    (globalThis as any).caches = {
+      keys: vi
+        .fn()
+        .mockResolvedValue([
+          "workbox-runtime-https://app/api-get-cache",
+          "other-cache",
+        ]),
+      delete: cacheDelete,
+    };
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+
+    // Only the two page.* databases are deleted.
+    expect(deleteDatabase).toHaveBeenCalledTimes(2);
+    expect(deleteDatabase).toHaveBeenCalledWith("page.aaa");
+    expect(deleteDatabase).toHaveBeenCalledWith("page.bbb");
+
+    // Only the api-get-cache entry is deleted.
+    expect(cacheDelete).toHaveBeenCalledTimes(1);
+    expect(cacheDelete).toHaveBeenCalledWith(
+      "workbox-runtime-https://app/api-get-cache",
+    );
+  });
+
+  it("never throws even if a step rejects (best-effort)", async () => {
+    h.del.mockRejectedValueOnce(new Error("idb boom"));
+    (globalThis as any).indexedDB = {
+      databases: vi.fn().mockRejectedValue(new Error("databases boom")),
+      deleteDatabase: vi.fn(),
+    };
+    (globalThis as any).caches = {
+      keys: vi.fn().mockRejectedValue(new Error("caches boom")),
+      delete: vi.fn(),
+    };
+
+    await expect(clearOfflineCache()).resolves.toBeUndefined();
+    expect(h.clear).toHaveBeenCalledTimes(1);
+  });
+});

apps/client/src/features/offline/clear-offline-cache.ts

@@ -0,0 +1,94 @@
+import { del } from "idb-keyval";
+
+import { queryClient } from "@/main.tsx";
+import { OFFLINE_CACHE_KEY } from "./query-persister";
+import { PAGE_YDOC_NAME_PREFIX } from "@/features/editor/page-ydoc-name";
+
+/**
+ * Best-effort purge of all of the current user's offline data from the browser.
+ *
+ * On logout the previous user's private data would otherwise linger locally and
+ * be readable by the next person on the device. This clears the three offline
+ * stores the app writes:
+ *   1. the in-memory + IndexedDB-persisted TanStack Query cache (idb-keyval key
+ *      `OFFLINE_CACHE_KEY`),
+ *   2. the Yjs page documents (IndexedDB databases named `page.<id>` created by
+ *      y-indexeddb in make-offline.ts), and
+ *   3. any legacy service worker `api-get-cache` Cache Storage entry. The
+ *      Workbox runtime no longer creates this cache (the GET /api NetworkFirst
+ *      rule was removed — offline reads come from the persisted RQ cache), so
+ *      this is now a defensive cleanup for caches left by older app versions.
+ *
+ * Fully best-effort: every step is isolated so a single failure neither blocks
+ * the remaining steps nor throws to the caller (logout must never be blocked on
+ * cache cleanup). Callers may ignore the resolved value.
+ *
+ * Limitations:
+ *   - Deleting the Yjs page databases relies on `indexedDB.databases()`, which
+ *     is unavailable in some browsers (notably Firefox). There we skip silently;
+ *     those `page.<id>` databases are then left in place.
+ *   - Cache Storage clearing only runs where `caches` exists (secure contexts /
+ *     service-worker-capable browsers).
+ */
+export async function clearOfflineCache(): Promise<void> {
+  // 1a. Drop the in-memory query cache immediately.
+  try {
+    queryClient.clear();
+  } catch {
+    // best-effort: ignore in-memory cache reset failures
+  }
+
+  // 1b. Delete the persisted RQ cache from IndexedDB.
+  try {
+    await del(OFFLINE_CACHE_KEY);
+  } catch {
+    // best-effort: ignore persisted-cache deletion failures
+  }
+
+  // 2. Delete the Yjs page IndexedDB databases (`page.<id>`).
+  // `indexedDB.databases()` is not implemented everywhere (e.g. Firefox); when
+  // it is missing we cannot enumerate the page databases, so we skip silently.
+  try {
+    if (
+      typeof indexedDB !== "undefined" &&
+      typeof indexedDB.databases === "function"
+    ) {
+      const dbs = await indexedDB.databases();
+      for (const db of dbs) {
+        const name = db?.name;
+        if (typeof name !== "string" || !name.startsWith(PAGE_YDOC_NAME_PREFIX))
+          continue;
+        try {
+          // Fire-and-forget delete; await a thin wrapper so a slow delete does
+          // not race the page teardown, but never reject on it.
+          await new Promise<void>((resolve) => {
+            const request = indexedDB.deleteDatabase(name);
+            request.onsuccess = () => resolve();
+            request.onerror = () => resolve();
+            request.onblocked = () => resolve();
+          });
+        } catch {
+          // best-effort per database
+        }
+      }
+    }
+  } catch {
+    // best-effort: ignore enumeration/deletion failures
+  }
+
+  // 3. Clear any legacy service worker API cache. Current builds no longer
+  // create it, but an older client may have left an "api-get-cache" entry
+  // (Workbox may prefix the name), so match by substring rather than exact name.
+  try {
+    if ("caches" in window) {
+      const keys = await caches.keys();
+      await Promise.all(
+        keys
+          .filter((key) => key.includes("api-get-cache"))
+          .map((key) => caches.delete(key)),
+      );
+    }
+  } catch {
+    // best-effort: ignore Cache Storage failures
+  }
+}

apps/client/src/features/offline/make-offline.test.ts

@@ -0,0 +1,373 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+
+// vi.mock factories are hoisted above imports, so any spy they reference must be
+// declared with vi.hoisted (which is hoisted as well). These shared spies are
+// inspected by the assertions below.
+const h = vi.hoisted(() => ({
+  ydocDestroy: vi.fn(),
+  idbDestroy: vi.fn(),
+  providerOn: vi.fn(),
+  providerOff: vi.fn(),
+  providerDestroy: vi.fn(),
+}));
+
+// The module under test imports the app entry at load time — it must be mocked.
+vi.mock("@/main.tsx", () => ({
+  queryClient: { setQueryData: vi.fn(), prefetchQuery: vi.fn() },
+}));
+vi.mock("@/features/page/services/page-service", () => ({
+  getPageById: vi.fn(),
+  getPageBreadcrumbs: vi.fn(),
+  getSidebarPages: vi.fn(),
+  getAllSidebarPages: vi.fn(),
+}));
+vi.mock("@/features/space/services/space-service.ts", () => ({
+  getSpaceById: vi.fn(),
+}));
+vi.mock("@/features/comment/services/comment-service", () => ({
+  getPageComments: vi.fn(),
+}));
+
+// Use the `function` form (not an arrow) so Vitest binds the constructor return
+// value when the module under test calls `new Y.Doc()` etc.
+vi.mock("yjs", () => ({
+  Doc: vi.fn(function () {
+    return { destroy: h.ydocDestroy };
+  }),
+}));
+vi.mock("y-indexeddb", () => ({
+  IndexeddbPersistence: vi.fn(function () {
+    return { destroy: h.idbDestroy };
+  }),
+}));
+vi.mock("@hocuspocus/provider", () => ({
+  HocuspocusProvider: vi.fn(function () {
+    return { on: h.providerOn, off: h.providerOff, destroy: h.providerDestroy };
+  }),
+}));
+
+import {
+  warmInfiniteAll,
+  warmPageYdoc,
+  makePageAvailableOffline,
+} from "./make-offline";
+import { queryClient } from "@/main.tsx";
+import {
+  getPageById,
+  getPageBreadcrumbs,
+  getSidebarPages,
+} from "@/features/page/services/page-service";
+import { getPageComments } from "@/features/comment/services/comment-service";
+
+const setQueryData = (queryClient as any).setQueryData as ReturnType<
+  typeof vi.fn
+>;
+const prefetchQuery = (queryClient as any).prefetchQuery as ReturnType<
+  typeof vi.fn
+>;
+
+beforeEach(() => {
+  // Clear call history WITHOUT wiping the mock implementations the vi.mock
+  // factories installed (vi.clearAllMocks would drop the constructor return
+  // objects and break the provider/idb/yjs spies).
+  setQueryData.mockClear();
+  prefetchQuery.mockReset();
+  prefetchQuery.mockResolvedValue(undefined);
+  (getPageById as ReturnType<typeof vi.fn>).mockReset();
+  (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockReset();
+  (getSidebarPages as ReturnType<typeof vi.fn>).mockReset();
+  (getPageComments as ReturnType<typeof vi.fn>).mockReset();
+  h.ydocDestroy.mockClear();
+  h.idbDestroy.mockClear();
+  h.providerOn.mockClear();
+  h.providerOff.mockClear();
+  h.providerDestroy.mockClear();
+});
+
+describe("warmInfiniteAll", () => {
+  it("warms a single page and writes the InfiniteData cache shape", async () => {
+    const res = { items: [{ id: 1 }], meta: { nextCursor: null } };
+    const fetchPage = vi.fn().mockResolvedValue(res);
+
+    await warmInfiniteAll(["comments", "p1"], fetchPage);
+
+    expect(fetchPage).toHaveBeenCalledTimes(1);
+    expect(fetchPage).toHaveBeenCalledWith(undefined);
+    expect(setQueryData).toHaveBeenCalledTimes(1);
+    expect(setQueryData).toHaveBeenCalledWith(["comments", "p1"], {
+      pages: [res],
+      pageParams: [undefined],
+    });
+  });
+
+  it("walks the cursor chain across multiple pages", async () => {
+    const r0 = { items: [], meta: { nextCursor: "c1" } };
+    const r1 = { items: [], meta: { nextCursor: "c2" } };
+    const r2 = { items: [], meta: { nextCursor: null } };
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValueOnce(r0)
+      .mockResolvedValueOnce(r1)
+      .mockResolvedValueOnce(r2);
+
+    await warmInfiniteAll(["comments", "p1"], fetchPage);
+
+    expect(fetchPage).toHaveBeenCalledTimes(3);
+    expect(fetchPage.mock.calls.map((c) => c[0])).toEqual([
+      undefined,
+      "c1",
+      "c2",
+    ]);
+    const payload = setQueryData.mock.calls[0][1];
+    expect(payload.pages).toEqual([r0, r1, r2]);
+    expect(payload.pageParams).toEqual([undefined, "c1", "c2"]);
+  });
+
+  it("caps pagination at maxPages and reports the truncation (returns false)", async () => {
+    // Always returns a non-null cursor — the cap is the only thing that stops it.
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValue({ items: [], meta: { nextCursor: "more" } });
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+    // Hitting maxPages with a cursor still pending is a truncated warm: the
+    // (partial) cache is still written, but the result is reported as false.
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage, 2),
+    ).resolves.toBe(false);
+
+    expect(fetchPage).toHaveBeenCalledTimes(2);
+    const payload = setQueryData.mock.calls[0][1];
+    expect(payload.pages).toHaveLength(2);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("returns true on success", async () => {
+    const fetchPage = vi
+      .fn()
+      .mockResolvedValue({ items: [], meta: { nextCursor: null } });
+
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage),
+    ).resolves.toBe(true);
+  });
+
+  it("reports errors (returns false) and never writes the cache on failure", async () => {
+    const fetchPage = vi.fn().mockRejectedValue(new Error("network"));
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+
+    await expect(
+      warmInfiniteAll(["comments", "p1"], fetchPage),
+    ).resolves.toBe(false);
+    expect(setQueryData).not.toHaveBeenCalled();
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+});
+
+describe("makePageAvailableOffline", () => {
+  const okPage = {
+    id: "uuid-1",
+    slugId: "slug-1",
+    space: { slug: "space-slug" },
+  };
+
+  it("returns ok:true with no failures when every step succeeds", async () => {
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result).toEqual({ ok: true, failed: [] });
+  });
+
+  it("returns ok:false with the failed step label when a warm step fails", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Comments warm fails -> labeled "comments".
+    (getPageComments as ReturnType<typeof vi.fn>).mockRejectedValue(
+      new Error("network"),
+    );
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    expect(result.ok).toBe(false);
+    expect(result.failed).toContain("comments");
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  // Helper: the page-ids passed to the sidebar-children warm (its query key is
+  // ["sidebar-pages", { pageId, spaceId }]) — i.e. which nodes were prefetched.
+  const warmedSidebarIds = () =>
+    prefetchQuery.mock.calls
+      .map((c) => c[0])
+      .filter((opts: any) => opts?.queryKey?.[0] === "sidebar-pages")
+      .map((opts: any) => opts.queryKey[1]?.pageId);
+
+  it("warms the page + every ancestor's children once and skips the self-ancestor guard", async () => {
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    // Breadcrumbs include two real ancestors, the page's OWN id (must be skipped
+    // by the ancestorId === pageId guard so it is not warmed twice), and a
+    // malformed entry with no id (also skipped).
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([
+      { id: "anc-1" },
+      { id: "uuid-1" }, // === pageId -> guard
+      { id: "anc-2" },
+      {}, // no id -> skipped
+    ]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    const ids = warmedSidebarIds();
+    // The page's own children (warmSidebarChildren(pageId)) plus each real
+    // ancestor — exactly once each. The self-ancestor (uuid-1 in breadcrumbs) is
+    // NOT a second warm: uuid-1 appears once (from the page's own children call).
+    expect(ids).toEqual(["uuid-1", "anc-1", "anc-2"]);
+    expect(ids.filter((id: string) => id === "uuid-1")).toHaveLength(1);
+    expect(result).toEqual({ ok: true, failed: [] });
+  });
+
+  it("dedupes repeated tree failures into a single 'tree' label", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockResolvedValue([
+      { id: "anc-1" },
+      { id: "anc-2" },
+    ]);
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    // Fail ONLY the sidebar-children prefetches (page-own + both ancestors = 3
+    // failures); the currentUser/space prefetches still resolve.
+    prefetchQuery.mockImplementation(async (opts: any) => {
+      if (opts?.queryKey?.[0] === "sidebar-pages") throw new Error("network");
+      return undefined;
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    // Three node warms failed but the contract collapses them to one "tree".
+    expect(result.ok).toBe(false);
+    expect(result.failed).toEqual(["tree"]);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+
+  it("records 'breadcrumbs' (not 'tree') when the breadcrumbs lookup rejects", async () => {
+    const errorSpy = vi.spyOn(console, "error").mockImplementation(() => {});
+    (getPageById as ReturnType<typeof vi.fn>).mockResolvedValue(okPage);
+    // Ancestor discovery fails -> the ancestor-walk is recorded as "breadcrumbs".
+    (getPageBreadcrumbs as ReturnType<typeof vi.fn>).mockRejectedValue(
+      new Error("network"),
+    );
+    (getSidebarPages as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+    (getPageComments as ReturnType<typeof vi.fn>).mockResolvedValue({
+      items: [],
+      meta: { nextCursor: null },
+    });
+
+    const result = await makePageAvailableOffline({
+      pageId: "uuid-1",
+      spaceId: "space-uuid",
+    });
+
+    // The page's own children still warmed fine (prefetch resolves), so the only
+    // failure is the breadcrumbs lookup.
+    expect(result.ok).toBe(false);
+    expect(result.failed).toEqual(["breadcrumbs"]);
+    expect(errorSpy).toHaveBeenCalled();
+
+    errorSpy.mockRestore();
+  });
+});
+
+describe("warmPageYdoc", () => {
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("resolves on synced, detaches the listener once, and tears everything down (settle-once)", async () => {
+    const promise = warmPageYdoc("p1", "ws://x");
+
+    // Grab the synced handler the provider registered.
+    expect(h.providerOn).toHaveBeenCalledWith("synced", expect.any(Function));
+    const handler = h.providerOn.mock.calls.find(
+      (c) => c[0] === "synced",
+    )![1] as () => void;
+
+    handler();
+    await expect(promise).resolves.toBeUndefined();
+
+    // Listener detached and everything cleaned up.
+    expect(h.providerOff).toHaveBeenCalledWith("synced", expect.any(Function));
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+
+    // Firing the handler again must NOT re-run cleanup (settled guard).
+    handler();
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+  });
+
+  it("resolves and cleans up after the timeout when synced never fires", async () => {
+    vi.useFakeTimers();
+    const promise = warmPageYdoc("p1", "ws://x");
+
+    // Do not fire "synced"; let the 8s safety timeout settle it.
+    await vi.advanceTimersByTimeAsync(8000);
+    await expect(promise).resolves.toBeUndefined();
+
+    expect(h.providerDestroy).toHaveBeenCalledTimes(1);
+    expect(h.idbDestroy).toHaveBeenCalledTimes(1);
+    expect(h.ydocDestroy).toHaveBeenCalledTimes(1);
+  });
+});

apps/client/src/features/offline/make-offline.ts

@@ -0,0 +1,315 @@
+import * as Y from "yjs";
+import { IndexeddbPersistence } from "y-indexeddb";
+import { HocuspocusProvider } from "@hocuspocus/provider";
+
+import { queryClient } from "@/main.tsx";
+import {
+  getPageById,
+  getPageBreadcrumbs,
+  getSidebarPages,
+} from "@/features/page/services/page-service";
+import {
+  pageKeys,
+  sidebarPagesQueryOptions,
+} from "@/features/page/queries/page-query";
+import { spaceByIdQueryOptions } from "@/features/space/queries/space-query";
+import { RQ_KEY } from "@/features/comment/queries/comment-query";
+import { getPageComments } from "@/features/comment/services/comment-service";
+import { getMyInfo } from "@/features/user/services/user-service";
+import { userKeys } from "@/features/user/hooks/use-current-user";
+import { IPage } from "@/features/page/types/page.types";
+import { IPagination } from "@/lib/types.ts";
+import { pageYdocName } from "@/features/editor/page-ydoc-name";
+
+/**
+ * Fully paginate an infinite query and write the @tanstack InfiniteData cache
+ * shape ({ pages, pageParams }) that the matching useInfiniteQuery hook reads.
+ *
+ * The default prefetchInfiniteQuery only warms the FIRST page, which leaves
+ * hooks that treat hasNextPage as still-loading (e.g. the comments panel)
+ * spinning forever offline, and silently truncates large lists. This walks the
+ * cursor chain until it runs out (or hits maxPages) so the whole list is cached.
+ *
+ * Best-effort: a failure does not throw (a partial/failed warm is still useful),
+ * but it is reported — the error is logged with context and `false` is returned
+ * so the caller can record the failed step instead of silently succeeding.
+ *
+ * Returns true ONLY if the cursor chain was fully exhausted and written. If the
+ * walk stops because it hit `maxPages` while a `nextCursor` is still pending,
+ * the cached list is truncated AND its last page keeps a nextCursor that cannot
+ * be re-fetched offline (hooks that gate on hasNextPage would spin forever), so
+ * that case is logged and returns false too — the caller records it as a failed
+ * warm instead of a silent truncated success. The (partial) cache is still
+ * written so what we did fetch is usable.
+ *
+ * Exported for unit testing of the cursor-walk / cache-write behavior.
+ */
+export async function warmInfiniteAll<T>(
+  queryKey: readonly unknown[],
+  fetchPage: (cursor: string | undefined) => Promise<IPagination<T>>,
+  maxPages = 50,
+): Promise<boolean> {
+  try {
+    const pages: IPagination<T>[] = [];
+    const pageParams: (string | undefined)[] = [];
+    let cursor: string | undefined = undefined;
+    let exhausted = false;
+
+    for (let i = 0; i < maxPages; i++) {
+      const res = await fetchPage(cursor);
+      pages.push(res);
+      pageParams.push(cursor);
+      cursor = res?.meta?.nextCursor ?? undefined;
+      if (!cursor) {
+        exhausted = true;
+        break;
+      }
+    }
+
+    queryClient.setQueryData(queryKey, { pages, pageParams });
+
+    if (!exhausted) {
+      // Stopped at maxPages with a cursor still pending: the list is truncated
+      // and the last cached page's nextCursor is un-fetchable offline. Report it
+      // as a failed warm rather than a silent truncated success.
+      console.error("warmInfiniteAll truncated at maxPages", {
+        queryKey,
+        maxPages,
+      });
+      return false;
+    }
+    return true;
+  } catch (error) {
+    console.error("warmInfiniteAll failed", { queryKey, error });
+    return false;
+  }
+}
+
+export interface MakePageAvailableOfflineParams {
+  pageId: string;
+  spaceId?: string;
+}
+
+/**
+ * Outcome of {@link makePageAvailableOffline}. `ok` is true only when every warm
+ * step succeeded; `failed` lists the labels of the steps that failed (a subset
+ * of: "currentUser", "page", "space", "tree", "breadcrumbs", "comments").
+ */
+export interface MakePageAvailableOfflineResult {
+  ok: boolean;
+  failed: string[];
+}
+
+/**
+ * Best-effort prefetch of a page's read queries so they get persisted to
+ * IndexedDB and become readable offline.
+ *
+ * Each step is isolated and this function does NOT throw — a partial warm is
+ * still useful. Instead of silently succeeding, every failed step is logged
+ * with a label and recorded in the returned result: `{ ok, failed }` where
+ * `ok` is true only if no step failed and `failed` lists the failed step
+ * labels. Only meaningful while online (the underlying requests must succeed).
+ */
+export async function makePageAvailableOffline({
+  pageId,
+  spaceId,
+}: MakePageAvailableOfflineParams): Promise<MakePageAvailableOfflineResult> {
+  const failed: string[] = [];
+
+  // Warm the current user (['currentUser']) so the auth-gated <Layout> can
+  // hydrate offline. UserProvider blanks the whole app while useCurrentUser has
+  // no data, and the offline POST /api/users/me fails as a network error, so
+  // without a persisted user a pinned page still white-screens after relaunch
+  // (#238). Persisted via OFFLINE_PERSIST_ROOTS; warmed here so the persisted
+  // cache actually has an entry to restore.
+  try {
+    await queryClient.prefetchQuery({
+      queryKey: userKeys.currentUser(),
+      queryFn: () => getMyInfo(),
+    });
+  } catch (error) {
+    console.error("makePageAvailableOffline: currentUser step failed", {
+      pageId,
+      error,
+    });
+    failed.push("currentUser");
+  }
+
+  // Fetch the page document ONCE and write it under BOTH cache keys, exactly
+  // like usePageQuery's onData effect. Every page consumer reads
+  // pageKeys.detail(slugId) (usePageQuery keys on the slugId for routed reads),
+  // so warming only the uuid key would leave the offline page blank.
+  let page: IPage | undefined;
+  try {
+    page = await getPageById({ pageId });
+    queryClient.setQueryData(pageKeys.detail(page.slugId), page);
+    queryClient.setQueryData(pageKeys.detail(page.id), page);
+  } catch (error) {
+    console.error("makePageAvailableOffline: page step failed", {
+      pageId,
+      error,
+    });
+    failed.push("page");
+  }
+
+  // Warm the space — page.tsx renders nothing until the space query resolves
+  // (useGetSpaceBySlugQuery). Awaited (not the fire-and-forget prefetchSpace) so
+  // the space is actually persisted before the caller fires its toast. Shares
+  // spaceByIdQueryOptions so the key/fn cannot drift from the hook.
+  try {
+    const spaceSlug = page?.space?.slug;
+    if (spaceSlug) {
+      await queryClient.prefetchQuery(spaceByIdQueryOptions(spaceSlug));
+    }
+  } catch (error) {
+    console.error("makePageAvailableOffline: space step failed", {
+      pageId,
+      error,
+    });
+    failed.push("space");
+  }
+
+  // Warm the sidebar tree root so the WHOLE root level renders offline (matches
+  // useGetRootSidebarPagesQuery's pageKeys.rootSidebar(spaceId) infinite cache).
+  // Fully paginated so large root levels are not truncated at 100.
+  if (spaceId) {
+    const ok = await warmInfiniteAll(pageKeys.rootSidebar(spaceId), (cursor) =>
+      getSidebarPages({ spaceId, cursor, limit: 100 }),
+    );
+    if (!ok) failed.push("tree");
+  }
+
+  // Warm the children of the page and of every ancestor so the path to this
+  // page is expandable offline. We MIRROR fetchAllAncestorChildren exactly via
+  // sidebarPagesQueryOptions — same pageKeys.sidebar({ pageId, spaceId }) key,
+  // same getAllSidebarPages fn (which aggregates ALL children pages, so nothing
+  // is truncated at 100), same 30min staleTime — otherwise the warmed cache
+  // would never be read by the offline tree.
+  const warmSidebarChildren = async (id: string): Promise<boolean> => {
+    try {
+      // Keep EXACTLY { pageId, spaceId } so the key hashes identically to
+      // fetchAllAncestorChildren's (no parentPageId, no extra fields).
+      const params = { pageId: id, spaceId };
+      await queryClient.prefetchQuery(sidebarPagesQueryOptions(params));
+      return true;
+    } catch (error) {
+      console.error("makePageAvailableOffline: tree node step failed", {
+        pageId: id,
+        error,
+      });
+      return false;
+    }
+  };
+
+  // The page's own children.
+  if (!(await warmSidebarChildren(pageId))) failed.push("tree");
+
+  // Each ancestor's children. Use the breadcrumbs endpoint ONLY to discover the
+  // ancestor ids — we intentionally do NOT cache the breadcrumbs themselves
+  // (the UI derives the path from the tree).
+  try {
+    const ancestors = (await getPageBreadcrumbs(pageId)) as
+      | Array<{ id?: string }>
+      | undefined;
+    for (const ancestor of ancestors ?? []) {
+      const ancestorId = ancestor?.id;
+      if (!ancestorId || ancestorId === pageId) continue;
+      if (!(await warmSidebarChildren(ancestorId))) failed.push("tree");
+    }
+  } catch (error) {
+    console.error("makePageAvailableOffline: breadcrumbs step failed", {
+      pageId,
+      error,
+    });
+    failed.push("breadcrumbs");
+  }
+
+  // Comments (matches useCommentsQuery's RQ_KEY(pageId) infinite cache).
+  // useCommentsQuery reports isLoading while hasNextPage is true, so warming
+  // only the first page leaves the offline comments panel spinning forever on
+  // pages with >100 comments. Fully paginate so the last cached page has no
+  // nextCursor and the panel settles offline.
+  const commentsOk = await warmInfiniteAll(RQ_KEY(pageId), (cursor) =>
+    getPageComments({ pageId, cursor, limit: 100 }),
+  );
+  if (!commentsOk) failed.push("comments");
+
+  // Dedupe — the tree label can be recorded once per failed node/ancestor.
+  const uniqueFailed = [...new Set(failed)];
+  return { ok: uniqueFailed.length === 0, failed: uniqueFailed };
+}
+
+/**
+ * Best-effort warm-up of the page's Yjs document into IndexedDB so the editor
+ * can open offline.
+ *
+ * Opens a local IndexeddbPersistence plus a transient HocuspocusProvider to
+ * pull the server state into IndexedDB, then tears both down once synced (or
+ * after a timeout). Entirely wrapped in try/catch — NEVER throws.
+ *
+ * Only meaningful when online at warm time; offline it is a no-op that resolves.
+ */
+export async function warmPageYdoc(
+  pageId: string,
+  collabUrl: string,
+  token?: string,
+): Promise<void> {
+  let ydoc: Y.Doc | null = null;
+  let local: IndexeddbPersistence | null = null;
+  let remote: HocuspocusProvider | null = null;
+
+  try {
+    const documentName = pageYdocName(pageId);
+    ydoc = new Y.Doc();
+    local = new IndexeddbPersistence(documentName, ydoc);
+    remote = new HocuspocusProvider({
+      url: collabUrl,
+      name: documentName,
+      document: ydoc,
+      token,
+    });
+
+    const provider = remote;
+
+    await new Promise<void>((resolve) => {
+      let settled = false;
+      let timeoutId: ReturnType<typeof setTimeout> | undefined;
+      const finish = () => {
+        if (settled) return;
+        settled = true;
+        // Clear the pending timeout and detach the listener so neither leaks
+        // after we resolve.
+        if (timeoutId !== undefined) clearTimeout(timeoutId);
+        try {
+          provider.off("synced", finish);
+        } catch {
+          // best-effort
+        }
+        resolve();
+      };
+
+      // Resolve once the server state has synced into the local doc...
+      provider.on("synced", finish);
+      // ...or give up after a short timeout so we never hang.
+      timeoutId = setTimeout(finish, 8000);
+    });
+  } catch {
+    // best-effort
+  } finally {
+    try {
+      remote?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      local?.destroy();
+    } catch {
+      // best-effort
+    }
+    try {
+      ydoc?.destroy();
+    } catch {
+      // best-effort
+    }
+  }
+}

apps/client/src/features/offline/offline-fallback.tsx

@@ -0,0 +1,45 @@
+import { Button, Container, Group, Stack, Text, Title } from "@mantine/core";
+import { Helmet } from "react-helmet-async";
+import { useTranslation } from "react-i18next";
+import { getAppName } from "@/lib/config";
+
+/**
+ * Shown when the authenticated app shell cannot hydrate because the current
+ * user is unavailable AND there is no cached user to fall back on (e.g. an
+ * offline cold boot of a page that was never warmed for offline).
+ *
+ * Previously UserProvider returned a bare `<></>` in this situation, which
+ * white-screened the whole app on any offline reload (#237/#238). Rendering an
+ * explicit "you're offline" state with a retry instead gives the user a clear,
+ * non-blank fallback and a way to recover once the network returns.
+ */
+export function OfflineFallback() {
+  const { t } = useTranslation();
+
+  return (
+    <>
+      <Helmet>
+        <title>
+          {t("You're offline")} - {getAppName()}
+        </title>
+      </Helmet>
+      <Container size="sm" py={80}>
+        <Stack align="center" gap="md">
+          <Title order={2} ta="center">
+            {t("You're offline")}
+          </Title>
+          <Text c="dimmed" size="lg" ta="center">
+            {t(
+              "This page hasn't been saved for offline use, so it can't be loaded right now. Reconnect to the internet and try again.",
+            )}
+          </Text>
+          <Group justify="center">
+            <Button onClick={() => window.location.reload()} variant="subtle">
+              {t("Retry")}
+            </Button>
+          </Group>
+        </Stack>
+      </Container>
+    </>
+  );
+}

apps/client/src/features/offline/offline-mutations.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { QueryClient, hydrate, dehydrate } from "@tanstack/react-query";
+
+// Stub the network services so a replayed mutation hits a spy, not the network.
+const h = vi.hoisted(() => ({
+  createPage: vi.fn(),
+  movePage: vi.fn(),
+  createComment: vi.fn(),
+}));
+
+vi.mock("@/features/page/services/page-service", () => ({
+  createPage: h.createPage,
+  movePage: h.movePage,
+}));
+vi.mock("@/features/comment/services/comment-service", () => ({
+  createComment: h.createComment,
+}));
+// page-query pulls in the app entry (queryClient) and a lot of UI deps via its
+// cache helpers; we only need invalidateOnCreatePage to be a no-op here.
+vi.mock("@/features/page/queries/page-query", () => ({
+  invalidateOnCreatePage: vi.fn(),
+}));
+
+import {
+  offlineMutationKeys,
+  registerOfflineMutationDefaults,
+} from "./offline-mutations";
+
+beforeEach(() => {
+  h.createPage.mockReset().mockResolvedValue({ id: "new-page" });
+  h.movePage.mockReset().mockResolvedValue(undefined);
+  h.createComment.mockReset().mockResolvedValue({ id: "new-comment" });
+});
+
+describe("registerOfflineMutationDefaults", () => {
+  it("registers a default mutationFn for every offline mutation key", () => {
+    const qc = new QueryClient();
+    registerOfflineMutationDefaults(qc);
+
+    for (const key of Object.values(offlineMutationKeys)) {
+      const defaults = qc.getMutationDefaults(key);
+      expect(typeof defaults?.mutationFn).toBe("function");
+    }
+  });
+
+  // The headline durability guarantee: a paused mutation dehydrated into
+  // IndexedDB while offline must, after a reload, have a mutationFn so
+  // resumePausedMutations() actually replays the write on reconnect.
+  it("makes a rehydrated paused create replayable by resumePausedMutations", async () => {
+    // 1) Simulate the offline tab: a paused create mutation gets dehydrated.
+    const offlineClient = new QueryClient();
+    const observer = offlineClient.getMutationCache().build(offlineClient, {
+      mutationKey: offlineMutationKeys.createPage,
+    });
+    // Force the dehydrate-worthy paused state (offline = isPaused) with the
+    // payload the user submitted before losing connectivity.
+    observer.state.isPaused = true;
+    observer.state.status = "pending";
+    observer.state.variables = { spaceId: "s1", title: "Offline page" };
+
+    const dehydrated = dehydrate(offlineClient, {
+      shouldDehydrateMutation: () => true,
+    });
+    expect(dehydrated.mutations).toHaveLength(1);
+    // The dehydrated mutation carries NO mutationFn (functions aren't
+    // serializable) — only its key + variables survive the reload.
+    expect((dehydrated.mutations[0] as any).mutationFn).toBeUndefined();
+
+    // 2) Simulate the fresh page after reload: register defaults, then hydrate
+    //    the persisted paused mutation back in.
+    const freshClient = new QueryClient();
+    registerOfflineMutationDefaults(freshClient);
+    hydrate(freshClient, dehydrated);
+
+    expect(freshClient.getMutationCache().getAll()).toHaveLength(1);
+
+    // 3) Reconnect: replay the paused mutations.
+    await freshClient.resumePausedMutations();
+
+    // The default mutationFn ran with the persisted variables — the write is
+    // NOT silently dropped.
+    expect(h.createPage).toHaveBeenCalledTimes(1);
+    expect(h.createPage).toHaveBeenCalledWith({
+      spaceId: "s1",
+      title: "Offline page",
+    });
+  });
+
+  it("makes a rehydrated paused move replayable by resumePausedMutations", async () => {
+    const offlineClient = new QueryClient();
+    const observer = offlineClient.getMutationCache().build(offlineClient, {
+      mutationKey: offlineMutationKeys.movePage,
+    });
+    observer.state.isPaused = true;
+    observer.state.status = "pending";
+    observer.state.variables = { pageId: "p1", parentPageId: null, position: "a" };
+
+    const dehydrated = dehydrate(offlineClient, {
+      shouldDehydrateMutation: () => true,
+    });
+
+    const freshClient = new QueryClient();
+    registerOfflineMutationDefaults(freshClient);
+    hydrate(freshClient, dehydrated);
+    await freshClient.resumePausedMutations();
+
+    expect(h.movePage).toHaveBeenCalledTimes(1);
+    expect(h.movePage).toHaveBeenCalledWith({
+      pageId: "p1",
+      parentPageId: null,
+      position: "a",
+    });
+  });
+});

apps/client/src/features/offline/offline-mutations.ts

@@ -0,0 +1,64 @@
+import type { QueryClient } from "@tanstack/react-query";
+import { createPage, movePage } from "@/features/page/services/page-service";
+import { createComment } from "@/features/comment/services/comment-service";
+import { invalidateOnCreatePage } from "@/features/page/queries/page-query";
+import type {
+  IMovePage,
+  IPage,
+  IPageInput,
+} from "@/features/page/types/page.types";
+import type { IComment } from "@/features/comment/types/comment.types";
+
+/**
+ * Stable mutation keys for the offline-relevant structural mutations.
+ *
+ * When the browser goes offline, React Query PAUSES these mutations and the
+ * PersistQueryClientProvider dehydrates the paused mutation into IndexedDB. On a
+ * reload-while-offline the mutation is restored, but a restored mutation has NO
+ * observer (no component is mounted) — so its replay relies entirely on the
+ * `mutationFn` registered via `setMutationDefaults` for its `mutationKey`.
+ * Without that, `resumePausedMutations()` finds a paused mutation with no
+ * `mutationFn` and silently no-ops, dropping the offline create/move/comment
+ * (#237/#238). Each offline mutation hook tags itself with the matching key so
+ * the rehydrated paused mutation can find its default `mutationFn` and replay.
+ */
+export const offlineMutationKeys = {
+  createPage: ["create-page"] as const,
+  movePage: ["move-page"] as const,
+  createComment: ["create-comment"] as const,
+};
+
+/**
+ * Register default `mutationFn`s (and the minimal success side effects safe to
+ * run without a mounted component) for the offline-relevant mutation keys, so a
+ * paused mutation restored from IndexedDB after an offline reload is replayable
+ * by `resumePausedMutations()` on reconnect.
+ *
+ * Called once when the QueryClient is created (see main.tsx). The hooks still
+ * carry their own inline `mutationFn`/`onSuccess` for the live in-session path;
+ * these defaults only take over for a rehydrated paused mutation that lost its
+ * observer across the reload.
+ */
+export function registerOfflineMutationDefaults(queryClient: QueryClient): void {
+  queryClient.setMutationDefaults(offlineMutationKeys.createPage, {
+    mutationFn: (data: Partial<IPageInput>) => createPage(data),
+    // Re-converge the sidebar tree / recent-changes from the authoritative
+    // create response. Pure cache writes — safe with no component mounted.
+    onSuccess: (data: IPage) => {
+      invalidateOnCreatePage(data);
+    },
+  });
+
+  queryClient.setMutationDefaults(offlineMutationKeys.movePage, {
+    // Replay the server-side move. The tree re-converges from the next online
+    // sidebar fetch / websocket `moveTreeNode` echo, so no cache write is
+    // needed here (the optimistic tree state was local-only anyway).
+    mutationFn: (data: IMovePage) => movePage(data),
+  });
+
+  queryClient.setMutationDefaults(offlineMutationKeys.createComment, {
+    // Replay the server-side comment create. The comments list refetches on the
+    // online reload, so the replay only needs to persist the write.
+    mutationFn: (data: Partial<IComment>) => createComment(data),
+  });
+}

apps/client/src/features/offline/persist-roots.guard.test.ts

@@ -0,0 +1,48 @@
+import { describe, it, expect } from "vitest";
+
+// The query modules transitively import the app entry (@/main.tsx) for the
+// shared queryClient; mock it so importing the key factories has no side effects.
+import { vi } from "vitest";
+vi.mock("@/main.tsx", () => ({
+  queryClient: { setQueryData: vi.fn(), getQueryData: vi.fn() },
+}));
+
+import { OFFLINE_PERSIST_ROOTS } from "./query-persister";
+import { pageKeys } from "@/features/page/queries/page-query";
+import { spaceKeys } from "@/features/space/queries/space-query";
+import { RQ_KEY } from "@/features/comment/queries/comment-query";
+import { userKeys } from "@/features/user/hooks/use-current-user";
+
+/**
+ * Architecture guard (#13): every string persisted via OFFLINE_PERSIST_ROOTS
+ * must be the ROOT (queryKey[0]) of some exported query-key factory. If a
+ * factory's root is renamed without updating the persist registry — or vice
+ * versa — offline persist/warm silently breaks (persisted keys never match the
+ * live queries). This turns that silent regression into a red build.
+ *
+ * Each factory is invoked with throwaway args; only queryKey[0] is inspected.
+ */
+function rootOf(key: readonly unknown[]): string {
+  return String(key[0]);
+}
+
+const FACTORY_ROOTS = new Set<string>([
+  rootOf(pageKeys.detail("x")),
+  rootOf(pageKeys.sidebar({})),
+  rootOf(pageKeys.rootSidebar("x")),
+  rootOf(pageKeys.breadcrumbs("x")),
+  rootOf(pageKeys.recentChanges("x")),
+  rootOf(spaceKeys.detail("x")),
+  rootOf(spaceKeys.list()),
+  rootOf(RQ_KEY("x")),
+  rootOf(userKeys.currentUser()),
+]);
+
+describe("OFFLINE_PERSIST_ROOTS is backed by real query-key factories", () => {
+  it("maps every persisted root to an exported factory root", () => {
+    const unbacked = [...OFFLINE_PERSIST_ROOTS].filter(
+      (root) => !FACTORY_ROOTS.has(root),
+    );
+    expect(unbacked).toEqual([]);
+  });
+});

apps/client/src/features/offline/query-persister.test.ts

@@ -0,0 +1,89 @@
+import { describe, it, expect } from "vitest";
+import {
+  shouldDehydrateOfflineQuery,
+  OFFLINE_PERSIST_ROOTS,
+} from "./query-persister";
+
+// Small helper to build the structural query shape the predicate reads.
+const makeQuery = (status: string, queryKey: readonly unknown[]) =>
+  ({ state: { status }, queryKey }) as any;
+
+describe("shouldDehydrateOfflineQuery", () => {
+  it("returns true for a successful query whose root is in the allowlist", () => {
+    expect(shouldDehydrateOfflineQuery(makeQuery("success", ["pages", "abc"]))).toBe(
+      true,
+    );
+    expect(
+      shouldDehydrateOfflineQuery(
+        makeQuery("success", ["sidebar-pages", { pageId: "p", spaceId: "s" }]),
+      ),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["comments", "p1"])),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["space", "s"])),
+    ).toBe(true);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["recent-changes"])),
+    ).toBe(true);
+    // currentUser is persisted so the auth-gated Layout can hydrate offline.
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["currentUser"])),
+    ).toBe(true);
+  });
+
+  it("returns false when the status is not success (status gate)", () => {
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("pending", ["pages", "abc"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("error", ["pages", "abc"])),
+    ).toBe(false);
+  });
+
+  it("returns false for a successful query whose root is NOT in the allowlist (privacy gate)", () => {
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["collab-token", "ws"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["trash", "s"])),
+    ).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", ["unknown"])),
+    ).toBe(false);
+  });
+
+  it("returns false for an empty/undefined queryKey", () => {
+    // String(undefined) is not a member of the allowlist.
+    expect(shouldDehydrateOfflineQuery(makeQuery("success", []))).toBe(false);
+    expect(
+      shouldDehydrateOfflineQuery(makeQuery("success", undefined as any)),
+    ).toBe(false);
+  });
+});
+
+describe("OFFLINE_PERSIST_ROOTS", () => {
+  it("contains exactly the expected 9 navigation/read roots", () => {
+    const expected = [
+      "pages",
+      "sidebar-pages",
+      "root-sidebar-pages",
+      "breadcrumbs",
+      "comments",
+      "space",
+      "spaces",
+      "recent-changes",
+      "currentUser",
+    ];
+    expect(OFFLINE_PERSIST_ROOTS.size).toBe(9);
+    for (const root of expected) {
+      expect(OFFLINE_PERSIST_ROOTS.has(root)).toBe(true);
+    }
+  });
+
+  it("does NOT contain volatile/auth keys", () => {
+    expect(OFFLINE_PERSIST_ROOTS.has("collab-token")).toBe(false);
+    expect(OFFLINE_PERSIST_ROOTS.has("trash")).toBe(false);
+  });
+});

apps/client/src/features/offline/query-persister.ts

@@ -0,0 +1,58 @@
+import { get, set, del } from "idb-keyval";
+import { createAsyncStoragePersister } from "@tanstack/query-async-storage-persister";
+
+// Structural subset of a TanStack Query we read when deciding what to persist.
+// We avoid importing the branded `Query` class because the persist-client and
+// react-query may resolve to different `@tanstack/query-core` copies, whose
+// `Query` types are nominally incompatible (private brand). This structural
+// shape stays assignable to whichever copy the persister expects.
+type DehydratableQuery = {
+  state: { status: string };
+  queryKey: readonly unknown[];
+};
+
+// idb-keyval key under which TanStack Query persists its dehydrated cache.
+// Exported so the logout cache-clear logic deletes the exact same key (no
+// magic-string drift between persist and purge).
+export const OFFLINE_CACHE_KEY = "gitmost-rq-cache";
+
+// IndexedDB-backed storage adapter for TanStack Query's async persister.
+const idbStorage = {
+  getItem: (key: string) => get<string>(key).then((v) => v ?? null),
+  setItem: (key: string, value: string) => set(key, value),
+  removeItem: (key: string) => del(key),
+};
+
+export const queryPersister = createAsyncStoragePersister({
+  storage: idbStorage,
+  key: OFFLINE_CACHE_KEY,
+  throttleTime: 1000,
+});
+
+// Only navigation/read query roots are persisted for offline reading.
+// Volatile/auth queries (collab tokens, trash lists) are intentionally excluded.
+//
+// `currentUser` IS persisted: UserProvider gates the entire <Layout> subtree on
+// useCurrentUser(), and offline the POST /api/users/me fails as a no-response
+// network error. Without the persisted/hydrated user the gate blanked every
+// authenticated route on an offline cold boot (#237/#238). It is the logged-in
+// user's own profile (already mirrored to localStorage["currentUser"]), so
+// persisting it to IndexedDB leaks nothing new while unlocking offline reads.
+export const OFFLINE_PERSIST_ROOTS = new Set<string>([
+  "pages",
+  "sidebar-pages",
+  "root-sidebar-pages",
+  "breadcrumbs",
+  "comments",
+  "space",
+  "spaces",
+  "recent-changes",
+  "currentUser",
+]);
+
+export function shouldDehydrateOfflineQuery(query: DehydratableQuery): boolean {
+  return (
+    query.state.status === "success" &&
+    OFFLINE_PERSIST_ROOTS.has(String(query.queryKey?.[0]))
+  );
+}

apps/client/src/features/page/components/header/page-header-menu.tsx

@@ -12,6 +12,8 @@ import {
   IconList,
   IconMarkdown,
   IconPrinter,
+  IconCloud,
+  IconCloudCheck,
   IconStar,
   IconStarFilled,
   IconTrash,
@@ -39,6 +41,8 @@ import { Trans, useTranslation } from "react-i18next";
 import ExportModal from "@/components/common/export-modal";
 import { htmlToMarkdown } from "@docmost/editor-ext";
 import {
+  isLocalSyncedAtom,
+  isRemoteSyncedAtom,
   pageEditorAtom,
   yjsConnectionStatusAtom,
 } from "@/features/editor/atoms/editor-atoms.ts";
@@ -411,14 +415,16 @@ function PageActionMenu({ readOnly }: PageActionMenuProps) {
 function ConnectionWarning() {
   const { t } = useTranslation();
   const yjsConnectionStatus = useAtomValue(yjsConnectionStatusAtom);
+  const isLocalSynced = useAtomValue(isLocalSyncedAtom);
+  const isRemoteSynced = useAtomValue(isRemoteSyncedAtom);
   const [showWarning, setShowWarning] = useState(false);
   const timeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
 
-  useEffect(() => {
-    const isDisconnected = ["disconnected", "connecting"].includes(
-      yjsConnectionStatus,
-    );
+  const isDisconnected = ["disconnected", "connecting"].includes(
+    yjsConnectionStatus,
+  );
 
+  useEffect(() => {
     if (isDisconnected) {
       if (!timeoutRef.current) {
         timeoutRef.current = setTimeout(() => setShowWarning(true), 5000);
@@ -430,7 +436,7 @@ function ConnectionWarning() {
       }
       setShowWarning(false);
     }
-  }, [yjsConnectionStatus]);
+  }, [isDisconnected]);
 
   // Cleanup only on unmount
   useEffect(() => {
@@ -441,22 +447,59 @@ function ConnectionWarning() {
     };
   }, []);
 
-  if (!showWarning) return null;
+  // State (1): offline/disconnected — changes are kept locally. Preserve the
+  // existing >5s debounce before surfacing this state.
+  if (isDisconnected) {
+    if (!showWarning) return null;
 
+    const offlineLabel = t(
+      "Offline — changes are saved locally and will sync when you reconnect",
+    );
+    return (
+      <Tooltip label={offlineLabel} openDelay={250} withArrow>
+        <ThemeIcon
+          variant="default"
+          c="red"
+          role="status"
+          aria-label={offlineLabel}
+          style={{ border: "none" }}
+        >
+          <IconWifiOff size={20} stroke={2} />
+        </ThemeIcon>
+      </Tooltip>
+    );
+  }
+
+  // State (2): connected but the remote replica is not fully caught up yet.
+  if (!isRemoteSynced || !isLocalSynced) {
+    const syncingLabel = t("Syncing changes…");
+    return (
+      <Tooltip label={syncingLabel} openDelay={250} withArrow>
+        <ThemeIcon
+          variant="default"
+          c="dimmed"
+          role="status"
+          aria-label={syncingLabel}
+          style={{ border: "none" }}
+        >
+          <IconCloud size={20} stroke={2} />
+        </ThemeIcon>
+      </Tooltip>
+    );
+  }
+
+  // State (3): fully synced — subtle confirmation indicator.
+  const syncedLabel = t("All changes synced");
   return (
-    <Tooltip
-      label={t("Real-time editor connection lost. Retrying...")}
-      openDelay={250}
-      withArrow
-    >
+    <Tooltip label={syncedLabel} openDelay={250} withArrow>
       <ThemeIcon
         variant="default"
-        c="red"
+        c="dimmed"
         role="status"
-        aria-label={t("Real-time editor connection lost. Retrying...")}
+        aria-label={syncedLabel}
         style={{ border: "none" }}
       >
-        <IconWifiOff size={20} stroke={2} />
+        <IconCloudCheck size={20} stroke={2} />
       </ThemeIcon>
     </Tooltip>
   );

apps/client/src/features/page/queries/page-query.ts

@@ -1,6 +1,7 @@
 import {
   InfiniteData,
   QueryKey,
+  queryOptions,
   useInfiniteQuery,
   UseInfiniteQueryResult,
   useMutation,
@@ -42,12 +43,38 @@ import { treeModel } from "@/features/page/tree/model/tree-model";
 import { SpaceTreeNode } from "@/features/page/tree/types";
 import { useQueryEmit } from "@/features/websocket/use-query-emit";
 import { moveToTrashNotificationMessage } from "@/features/page/components/move-to-trash-notification";
+import { offlineMutationKeys } from "@/features/offline/offline-mutations";
+
+/**
+ * Centralized React Query key factories for page queries. The hooks below and
+ * the offline warm path (features/offline/make-offline.ts) share these so the
+ * runtime keys can never silently drift apart.
+ */
+export const pageKeys = {
+  detail: (idOrSlug: string) => ["pages", idOrSlug] as const,
+  sidebar: (data: unknown) => ["sidebar-pages", data] as const,
+  rootSidebar: (spaceId: string) => ["root-sidebar-pages", spaceId] as const,
+  breadcrumbs: (pageId: string) => ["breadcrumbs", pageId] as const,
+  recentChanges: (spaceId?: string) => ["recent-changes", spaceId] as const,
+};
+
+/**
+ * Shared queryOptions for the sidebar-pages (ancestor children) query. Both
+ * fetchAllAncestorChildren and the offline warm path consume this so the key,
+ * queryFn and staleTime stay identical.
+ */
+export const sidebarPagesQueryOptions = (params: SidebarPagesParams) =>
+  queryOptions({
+    queryKey: pageKeys.sidebar(params),
+    queryFn: () => getAllSidebarPages(params),
+    staleTime: 30 * 60 * 1000,
+  });
 
 export function usePageQuery(
   pageInput: Partial<IPageInput>,
 ): UseQueryResult<IPage, Error> {
   const query = useQuery({
-    queryKey: ["pages", pageInput.pageId],
+    queryKey: pageKeys.detail(pageInput.pageId),
     queryFn: () => getPageById(pageInput),
     enabled: !!pageInput.pageId,
     staleTime: 5 * 60 * 1000,
@@ -56,9 +83,9 @@ export function usePageQuery(
   useEffect(() => {
     if (query.data) {
       if (isValidUuid(pageInput.pageId)) {
-        queryClient.setQueryData(["pages", query.data.slugId], query.data);
+        queryClient.setQueryData(pageKeys.detail(query.data.slugId), query.data);
       } else {
-        queryClient.setQueryData(["pages", query.data.id], query.data);
+        queryClient.setQueryData(pageKeys.detail(query.data.id), query.data);
       }
     }
   }, [query.data]);
@@ -69,6 +96,10 @@ export function usePageQuery(
 export function useCreatePageMutation() {
   const { t } = useTranslation();
   return useMutation<IPage, Error, Partial<IPageInput>>({
+    // Stable key so a paused create restored from IndexedDB after an offline
+    // reload finds its default mutationFn (registerOfflineMutationDefaults) and
+    // is replayed by resumePausedMutations() on reconnect instead of being lost.
+    mutationKey: offlineMutationKeys.createPage,
     mutationFn: (data) => createPage(data),
     onSuccess: (data) => {
       invalidateOnCreatePage(data);
@@ -80,18 +111,20 @@ export function useCreatePageMutation() {
 }
 
 export function updatePageData(data: IPage) {
-  const pageBySlug = queryClient.getQueryData<IPage>(["pages", data.slugId]);
-  const pageById = queryClient.getQueryData<IPage>(["pages", data.id]);
+  const pageBySlug = queryClient.getQueryData<IPage>(
+    pageKeys.detail(data.slugId),
+  );
+  const pageById = queryClient.getQueryData<IPage>(pageKeys.detail(data.id));
 
   if (pageBySlug) {
-    queryClient.setQueryData(["pages", data.slugId], {
+    queryClient.setQueryData(pageKeys.detail(data.slugId), {
       ...pageBySlug,
       ...data,
     });
   }
 
   if (pageById) {
-    queryClient.setQueryData(["pages", data.id], { ...pageById, ...data });
+    queryClient.setQueryData(pageKeys.detail(data.id), { ...pageById, ...data });
   }
 
   invalidateOnUpdatePage(
@@ -145,11 +178,11 @@ export function useRemovePageMutation() {
       });
 
       // Stamp deletedAt so a re-visit shows the trash banner, not stale state.
-      const cached = queryClient.getQueryData<IPage>(["pages", pageId]);
+      const cached = queryClient.getQueryData<IPage>(pageKeys.detail(pageId));
       if (cached) {
         const stamped = { ...cached, deletedAt: new Date() };
-        queryClient.setQueryData(["pages", cached.id], stamped);
-        queryClient.setQueryData(["pages", cached.slugId], stamped);
+        queryClient.setQueryData(pageKeys.detail(cached.id), stamped);
+        queryClient.setQueryData(pageKeys.detail(cached.slugId), stamped);
       }
 
       invalidateOnDeletePage(pageId);
@@ -188,6 +221,9 @@ export function useDeletePageMutation() {
 
 export function useMovePageMutation() {
   return useMutation<void, Error, IMovePage>({
+    // Stable key so a paused move restored from IndexedDB after an offline
+    // reload finds its default mutationFn and is replayed on reconnect.
+    mutationKey: offlineMutationKeys.movePage,
     mutationFn: (data) => movePage(data),
   });
 }
@@ -267,8 +303,11 @@ export function useRestorePageMutation() {
       // Replace would strip space/permissions/content and break the editor.
       const merge = (cached: IPage | undefined) =>
         cached ? { ...cached, ...restoredPage } : cached;
-      queryClient.setQueryData<IPage>(["pages", restoredPage.id], merge);
-      queryClient.setQueryData<IPage>(["pages", restoredPage.slugId], merge);
+      queryClient.setQueryData<IPage>(pageKeys.detail(restoredPage.id), merge);
+      queryClient.setQueryData<IPage>(
+        pageKeys.detail(restoredPage.slugId),
+        merge,
+      );
     },
     onError: (error) => {
       notifications.show({
@@ -283,7 +322,7 @@ export function useGetSidebarPagesQuery(
   data: SidebarPagesParams | null,
 ): UseInfiniteQueryResult<InfiniteData<IPagination<IPage>, unknown>> {
   return useInfiniteQuery({
-    queryKey: ["sidebar-pages", data],
+    queryKey: pageKeys.sidebar(data),
     enabled: !!data?.pageId || !!data?.spaceId,
     queryFn: ({ pageParam }) =>
       getSidebarPages({ ...data, cursor: pageParam, limit: 100 }),
@@ -294,7 +333,7 @@ export function useGetSidebarPagesQuery(
 
 export function useGetRootSidebarPagesQuery(data: SidebarPagesParams) {
   return useInfiniteQuery({
-    queryKey: ["root-sidebar-pages", data.spaceId],
+    queryKey: pageKeys.rootSidebar(data.spaceId),
     queryFn: async ({ pageParam }) => {
       return getSidebarPages({
         spaceId: data.spaceId,
@@ -320,7 +359,7 @@ export function usePageBreadcrumbsQuery(
   pageId: string,
 ): UseQueryResult<Partial<IPage[]>, Error> {
   return useQuery({
-    queryKey: ["breadcrumbs", pageId],
+    queryKey: pageKeys.breadcrumbs(pageId),
     queryFn: () => getPageBreadcrumbs(pageId),
     enabled: !!pageId,
   });
@@ -332,10 +371,12 @@ export async function fetchAllAncestorChildren(
   // refresh (#159 #8), which must NOT receive the 30-min-cached children.
   opts?: { fresh?: boolean },
 ) {
-  // not using a hook here, so we can call it inside a useEffect hook
+  // not using a hook here, so we can call it inside a useEffect hook. Reuse the
+  // shared sidebarPagesQueryOptions (key + queryFn) so the offline warm path and
+  // this fetch never drift, but override staleTime for the `fresh` reconnect
+  // refresh (#159 #8), which must force a server refetch (staleTime 0).
   const response = await queryClient.fetchQuery({
-    queryKey: ["sidebar-pages", params],
-    queryFn: () => getAllSidebarPages(params),
+    ...sidebarPagesQueryOptions(params),
     staleTime: opts?.fresh ? 0 : 30 * 60 * 1000,
   });
 
@@ -345,7 +386,7 @@ export async function fetchAllAncestorChildren(
 
 export function useRecentChangesQuery(spaceId?: string) {
   return useInfiniteQuery({
-    queryKey: ["recent-changes", spaceId],
+    queryKey: pageKeys.recentChanges(spaceId),
     queryFn: ({ pageParam }) =>
       getRecentChanges({ spaceId, cursor: pageParam, limit: 15 }),
     initialPageParam: undefined as string | undefined,
@@ -416,12 +457,12 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
   let queryKey: QueryKey = null;
   if (data.parentPageId === null) {
-    queryKey = ["root-sidebar-pages", data.spaceId];
+    queryKey = pageKeys.rootSidebar(data.spaceId);
   } else {
-    queryKey = [
-      "sidebar-pages",
-      { pageId: data.parentPageId, spaceId: data.spaceId },
-    ];
+    queryKey = pageKeys.sidebar({
+      pageId: data.parentPageId,
+      spaceId: data.spaceId,
+    });
   }
 
   //update all sidebar pages
@@ -481,7 +522,7 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
     //update root sidebar pages haschildern
     const rootSideBarMatches = queryClient.getQueriesData({
-      queryKey: ["root-sidebar-pages", data.spaceId],
+      queryKey: pageKeys.rootSidebar(data.spaceId),
       exact: false,
     });
 
@@ -505,7 +546,7 @@ export function invalidateOnCreatePage(data: Partial<IPage>) {
 
   //update recent changes
   queryClient.invalidateQueries({
-    queryKey: ["recent-changes", data.spaceId],
+    queryKey: pageKeys.recentChanges(data.spaceId),
   });
 }
 
@@ -519,9 +560,9 @@ export function invalidateOnUpdatePage(
   invalidatePageTree();
   let queryKey: QueryKey = null;
   if (parentPageId === null) {
-    queryKey = ["root-sidebar-pages", spaceId];
+    queryKey = pageKeys.rootSidebar(spaceId);
   } else {
-    queryKey = ["sidebar-pages", { pageId: parentPageId, spaceId: spaceId }];
+    queryKey = pageKeys.sidebar({ pageId: parentPageId, spaceId: spaceId });
   }
   //update all sidebar pages
   queryClient.setQueryData<InfiniteData<IPagination<IPage>>>(
@@ -544,7 +585,7 @@ export function invalidateOnUpdatePage(
 
   //update recent changes
   queryClient.invalidateQueries({
-    queryKey: ["recent-changes", spaceId],
+    queryKey: pageKeys.recentChanges(spaceId),
   });
 }
 
@@ -559,8 +600,8 @@ export function updateCacheOnMovePage(
   // Remove page from old parent's cache
   const oldQueryKey =
     oldParentId === null
-      ? ["root-sidebar-pages", spaceId]
-      : ["sidebar-pages", { pageId: oldParentId, spaceId }];
+      ? pageKeys.rootSidebar(spaceId)
+      : pageKeys.sidebar({ pageId: oldParentId, spaceId });
 
   queryClient.setQueryData<InfiniteData<IPagination<IPage>>>(
     oldQueryKey,
@@ -580,7 +621,7 @@ export function updateCacheOnMovePage(
   if (oldParentId !== null) {
     const oldParentCache = queryClient.getQueryData<
       InfiniteData<IPagination<IPage>>
-    >(["sidebar-pages", { pageId: oldParentId, spaceId }]);
+    >(pageKeys.sidebar({ pageId: oldParentId, spaceId }));
 
     const remainingChildren =
       oldParentCache?.pages.flatMap((p) => p.items).length ?? 0;
@@ -618,8 +659,8 @@ export function updateCacheOnMovePage(
   // Add page to new parent's cache
   const newQueryKey =
     newParentId === null
-      ? ["root-sidebar-pages", spaceId]
-      : ["sidebar-pages", { pageId: newParentId, spaceId }];
+      ? pageKeys.rootSidebar(spaceId)
+      : pageKeys.sidebar({ pageId: newParentId, spaceId });
 
   queryClient.setQueryData<InfiniteData<IPagination<Partial<IPage>>>>(
     newQueryKey,

apps/client/src/features/page/tree/components/space-tree-node-menu.tsx

@@ -7,6 +7,7 @@ import { notifications } from "@mantine/notifications";
 import {
   IconArrowRight,
   IconClockHour4,
+  IconCloudDownload,
   IconCopy,
   IconDotsVertical,
   IconFileExport,
@@ -35,6 +36,12 @@ import {
   useToggleTemplateMutation,
   useToggleTemporaryMutation,
 } from "@/features/page-embed/queries/page-embed-query";
+import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
+import { getCollaborationUrl } from "@/lib/config.ts";
+import {
+  makePageAvailableOffline,
+  warmPageYdoc,
+} from "@/features/offline/make-offline";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
 import { treeModel } from "@/features/page/tree/model/tree-model";
 import { pageToTreeNode } from "@/features/page/tree/utils";
@@ -72,6 +79,45 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
   const isTemplate = !!node.isTemplate;
   const toggleTemporary = useToggleTemporaryMutation();
   const isTemporary = !!node.temporaryExpiresAt;
+  const { data: collabQuery } = useCollabToken();
+
+  const handleMakeAvailableOffline = async () => {
+    notifications.show({ message: t("Saving page for offline use...") });
+    try {
+      // Prefetch read queries so they get persisted to IndexedDB. The result
+      // reports whether every warm step succeeded.
+      const result = await makePageAvailableOffline({
+        pageId: node.id,
+        spaceId: node.spaceId,
+      });
+      // Best-effort: warm the page's Yjs document into IndexedDB.
+      await warmPageYdoc(node.id, getCollaborationUrl(), collabQuery?.token);
+
+      if (result.ok) {
+        notifications.show({ message: t("Page is now available offline") });
+      } else {
+        // Partial warm — the page may still be partly usable offline, but some
+        // queries failed to cache, so surface it as an error rather than a
+        // silent success.
+        notifications.show({
+          message: t("Failed to make page available offline"),
+          color: "red",
+        });
+      }
+    } catch (err) {
+      // makePageAvailableOffline no longer throws, but warmPageYdoc and other
+      // unexpected failures stay guarded here. Log the raw error and surface the
+      // real cause to the user instead of a bare generic string (AGENTS.md).
+      console.error("handleMakeAvailableOffline failed", err);
+      const reason =
+        (err as { response?: { data?: { message?: string } } })?.response?.data
+          ?.message ?? (err instanceof Error ? err.message : String(err));
+      notifications.show({
+        message: `${t("Failed to make page available offline")}: ${reason}`,
+        color: "red",
+      });
+    }
+  };
 
   const handleToggleTemplate = async () => {
     const next = !isTemplate;
@@ -228,6 +274,17 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
             {t("Export")}
           </Menu.Item>
 
+          <Menu.Item
+            leftSection={<IconCloudDownload size={16} />}
+            onClick={(e) => {
+              e.preventDefault();
+              e.stopPropagation();
+              handleMakeAvailableOffline();
+            }}
+          >
+            {t("Make available offline")}
+          </Menu.Item>
+
           {canEdit && (
             <>
               <Menu.Item

apps/client/src/features/page/tree/hooks/use-tree-mutation.ts

@@ -15,7 +15,6 @@ import {
   useCreatePageMutation,
   useRemovePageMutation,
   useMovePageMutation,
-  useUpdatePageMutation,
   updateCacheOnMovePage,
 } from "@/features/page/queries/page-query.ts";
 import { buildPageUrl } from "@/features/page/page.utils.ts";
@@ -27,7 +26,6 @@ export type UseTreeMutation = {
     parentId: string | null,
     opts?: { temporary?: boolean },
   ) => Promise<void>;
-  handleRename: (id: string, name: string) => Promise<void>;
   handleDelete: (id: string) => Promise<void>;
 };
 
@@ -39,7 +37,6 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
   // children) and then immediately invokes a handler.
   const store = useStore();
   const createPageMutation = useCreatePageMutation();
-  const updatePageMutation = useUpdatePageMutation();
   const removePageMutation = useRemovePageMutation();
   const movePageMutation = useMovePageMutation();
   const navigate = useNavigate();
@@ -205,20 +202,6 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
     [spaceId, createPageMutation, setData, store, navigate, spaceSlug],
   );
 
-  const handleRename = useCallback(
-    async (id: string, name: string) => {
-      setData((prev) =>
-        treeModel.update(prev, id, { name } as Partial<SpaceTreeNode>),
-      );
-      try {
-        await updatePageMutation.mutateAsync({ pageId: id, title: name });
-      } catch (error) {
-        console.error("Error updating page title:", error);
-      }
-    },
-    [updatePageMutation, setData],
-  );
-
   const handleDelete = useCallback(
     async (id: string) => {
       const node = treeModel.find(
@@ -264,7 +247,7 @@ export function useTreeMutation(spaceId: string): UseTreeMutation {
     [removePageMutation, setData, store, pageSlug, navigate, spaceSlug],
   );
 
-  return { handleMove, handleCreate, handleRename, handleDelete };
+  return { handleMove, handleCreate, handleDelete };
 }
 
 function isPageInNode(node: SpaceTreeNode, pageSlug: string): boolean {

apps/client/src/features/space/queries/space-query.ts

@@ -1,5 +1,6 @@
 import {
   keepPreviousData,
+  queryOptions,
   useInfiniteQuery,
   useMutation,
   useQuery,
@@ -31,11 +32,37 @@ import { getRecentChanges } from "@/features/page/services/page-service.ts";
 import { useEffect } from "react";
 import { validate as isValidUuid } from "uuid";
 
+/**
+ * Centralized React Query key factories for space queries. The hooks below and
+ * the offline warm path (features/offline/make-offline.ts) share these so the
+ * runtime keys can never silently drift apart.
+ */
+export const spaceKeys = {
+  detail: (idOrSlug: string) => ["space", idOrSlug] as const,
+  list: (params?: QueryParams) => ["spaces", params] as const,
+  members: (spaceId: string, query?: string) =>
+    ["spaceMembers", spaceId, query] as const,
+};
+
+/**
+ * Shared queryOptions for fetching a space by id/slug. Both
+ * useGetSpaceBySlugQuery and the offline warm path consume this so the key,
+ * queryFn and staleTime stay identical. (`enabled` is intentionally omitted —
+ * prefetchQuery ignores it anyway and the warm path always passes a real id;
+ * the hook reapplies `enabled` itself.)
+ */
+export const spaceByIdQueryOptions = (spaceId: string) =>
+  queryOptions({
+    queryKey: spaceKeys.detail(spaceId),
+    queryFn: () => getSpaceById(spaceId),
+    staleTime: 5 * 60 * 1000,
+  });
+
 export function useGetSpacesQuery(
   params?: QueryParams,
 ): UseQueryResult<IPagination<ISpace>, Error> {
   return useQuery({
-    queryKey: ["spaces", params],
+    queryKey: spaceKeys.list(params),
     queryFn: () => getSpaces(params),
     placeholderData: keepPreviousData,
     refetchOnMount: true,
@@ -44,16 +71,16 @@ export function useGetSpacesQuery(
 
 export function useSpaceQuery(spaceId: string): UseQueryResult<ISpace, Error> {
   const query = useQuery({
-    queryKey: ["space", spaceId],
+    queryKey: spaceKeys.detail(spaceId),
     queryFn: () => getSpaceById(spaceId),
     enabled: !!spaceId,
   });
   useEffect(() => {
     if (query.data) {
       if (isValidUuid(spaceId)) {
-        queryClient.setQueryData(["space", query.data.slug], query.data);
+        queryClient.setQueryData(spaceKeys.detail(query.data.slug), query.data);
       } else {
-        queryClient.setQueryData(["space", query.data.id], query.data);
+        queryClient.setQueryData(spaceKeys.detail(query.data.id), query.data);
       }
     }
   }, [query.data]);
@@ -62,8 +89,11 @@ export function useSpaceQuery(spaceId: string): UseQueryResult<ISpace, Error> {
 }
 
 export const prefetchSpace = (spaceSlug: string, spaceId?: string) => {
+  // Note: intentionally NOT using spaceByIdQueryOptions here — that factory sets
+  // a 5min staleTime which would let this prefetch skip fetching fresh data;
+  // prefetchSpace must always refetch (default staleTime: 0).
   queryClient.prefetchQuery({
-    queryKey: ["space", spaceSlug],
+    queryKey: spaceKeys.detail(spaceSlug),
     queryFn: () => getSpaceById(spaceSlug),
   });
 
@@ -100,10 +130,8 @@ export function useGetSpaceBySlugQuery(
   spaceId: string,
 ): UseQueryResult<ISpace, Error> {
   return useQuery({
-    queryKey: ["space", spaceId],
-    queryFn: () => getSpaceById(spaceId),
+    ...spaceByIdQueryOptions(spaceId),
     enabled: !!spaceId,
-    staleTime: 5 * 60 * 1000,
   });
 }
 
@@ -116,14 +144,16 @@ export function useUpdateSpaceMutation() {
     onSuccess: (data, variables) => {
       notifications.show({ message: t("Space updated successfully") });
 
-      const space = queryClient.getQueryData([
-        "space",
-        variables.spaceId,
-      ]) as ISpace;
+      const space = queryClient.getQueryData(
+        spaceKeys.detail(variables.spaceId),
+      ) as ISpace;
       if (space) {
         const updatedSpace = { ...space, ...data };
-        queryClient.setQueryData(["space", variables.spaceId], updatedSpace);
-        queryClient.setQueryData(["space", data.slug], updatedSpace);
+        queryClient.setQueryData(
+          spaceKeys.detail(variables.spaceId),
+          updatedSpace,
+        );
+        queryClient.setQueryData(spaceKeys.detail(data.slug), updatedSpace);
       }
 
       queryClient.invalidateQueries({
@@ -148,7 +178,7 @@ export function useDeleteSpaceMutation() {
 
       if (variables.slug) {
         queryClient.removeQueries({
-          queryKey: ["space", variables.slug],
+          queryKey: spaceKeys.detail(variables.slug),
           exact: true,
         });
       }
@@ -156,7 +186,7 @@ export function useDeleteSpaceMutation() {
       // Remove space-specific queries
       if (variables.id) {
         queryClient.removeQueries({
-          queryKey: ["space", variables.id],
+          queryKey: spaceKeys.detail(variables.id),
           exact: true,
         });
 
@@ -196,7 +226,7 @@ export function useSpaceMembersInfiniteQuery(
   query?: string,
 ) {
   return useInfiniteQuery({
-    queryKey: ["spaceMembers", spaceId, query],
+    queryKey: spaceKeys.members(spaceId, query),
     queryFn: ({ pageParam }) =>
       getSpaceMembers(spaceId, { cursor: pageParam, limit: 50, query }),
     enabled: !!spaceId,

apps/client/src/features/user/hooks/use-current-user.ts

@@ -2,9 +2,19 @@ import { useQuery, UseQueryResult } from "@tanstack/react-query";
 import { getMyInfo } from "@/features/user/services/user-service";
 import { ICurrentUser } from "@/features/user/types/user.types";
 
+/**
+ * Centralized React Query key factory for current-user queries. This hook and
+ * the offline warm path (features/offline/make-offline.ts) share it so the
+ * runtime key can never silently drift, and the OFFLINE_PERSIST_ROOTS guard
+ * test can assert the persisted "currentUser" root maps to a real factory.
+ */
+export const userKeys = {
+  currentUser: () => ["currentUser"] as const,
+};
+
 export default function useCurrentUser(): UseQueryResult<ICurrentUser> {
   return useQuery({
-    queryKey: ["currentUser"],
+    queryKey: userKeys.currentUser(),
     queryFn: async () => {
       return await getMyInfo();
     },

apps/client/src/features/user/user-provider.test.tsx

@@ -0,0 +1,118 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen } from "@testing-library/react";
+import { MantineProvider } from "@mantine/core";
+import { MemoryRouter } from "react-router-dom";
+import { HelmetProvider } from "react-helmet-async";
+
+// Control useCurrentUser per test; stub the rest of UserProvider's network/
+// socket dependencies so we only exercise its render-gating logic.
+const h = vi.hoisted(() => ({ useCurrentUser: vi.fn() }));
+
+vi.mock("@/features/user/hooks/use-current-user", () => ({
+  default: h.useCurrentUser,
+}));
+vi.mock("@/features/auth/queries/auth-query.tsx", () => ({
+  useCollabToken: () => ({ data: undefined }),
+}));
+vi.mock("@/features/websocket/use-query-subscription.ts", () => ({
+  useQuerySubscription: () => {},
+}));
+vi.mock("@/features/websocket/use-tree-socket.ts", () => ({
+  useTreeSocket: () => {},
+}));
+vi.mock("@/features/notification/hooks/use-notification-socket.ts", () => ({
+  useNotificationSocket: () => {},
+}));
+vi.mock("@/main.tsx", () => ({ queryClient: {} }));
+vi.mock("@/features/user/connect-resync.ts", () => ({
+  makeConnectHandler: () => () => {},
+}));
+vi.mock("socket.io-client", () => ({
+  io: () => ({ on: vi.fn(), disconnect: vi.fn() }),
+}));
+vi.mock("react-i18next", () => ({
+  useTranslation: () => ({
+    t: (k: string) => k,
+    i18n: {
+      changeLanguage: vi.fn(),
+      language: "en-US",
+      resolvedLanguage: "en-US",
+    },
+  }),
+}));
+
+import { UserProvider } from "./user-provider";
+
+const networkError = { message: "Network Error" }; // axios network error: no `response`
+
+function renderProvider() {
+  return render(
+    <HelmetProvider>
+      <MemoryRouter>
+        <MantineProvider>
+          <UserProvider>
+            <div data-testid="app-child">app content</div>
+          </UserProvider>
+        </MantineProvider>
+      </MemoryRouter>
+    </HelmetProvider>,
+  );
+}
+
+beforeEach(() => {
+  h.useCurrentUser.mockReset();
+});
+
+describe("UserProvider offline render-gating", () => {
+  it("renders the app (cached children) when useCurrentUser errors offline but a cached user exists", () => {
+    // Offline reload: the persisted ['currentUser'] cache hydrates `data`, but
+    // the background POST /api/users/me refetch fails as a network error.
+    h.useCurrentUser.mockReturnValue({
+      data: {
+        user: { id: "u1", locale: "en" },
+        workspace: { id: "w1" },
+      },
+      isLoading: false,
+      error: networkError,
+      isError: true,
+    });
+
+    renderProvider();
+
+    // The cached app must render — NOT a blank fragment (#237/#238).
+    expect(screen.getByTestId("app-child")).toBeDefined();
+    expect(screen.queryByText("You're offline")).toBeNull();
+  });
+
+  it("renders the offline fallback (not a blank fragment) when erroring with no cached user", () => {
+    h.useCurrentUser.mockReturnValue({
+      data: undefined,
+      isLoading: false,
+      error: networkError,
+      isError: true,
+    });
+
+    const { container } = renderProvider();
+
+    // Previously this returned `<></>` — a blank white screen. Now it must show
+    // an explicit offline fallback.
+    expect(screen.getByText("You're offline")).toBeDefined();
+    expect(screen.queryByTestId("app-child")).toBeNull();
+    expect(container.textContent?.length).toBeGreaterThan(0);
+  });
+
+  it("renders the app normally on a successful currentUser load", () => {
+    h.useCurrentUser.mockReturnValue({
+      data: {
+        user: { id: "u1", locale: "en" },
+        workspace: { id: "w1" },
+      },
+      isLoading: false,
+      error: null,
+      isError: false,
+    });
+
+    renderProvider();
+    expect(screen.getByTestId("app-child")).toBeDefined();
+  });
+});

apps/client/src/features/user/user-provider.tsx

@@ -11,6 +11,7 @@ import { useTreeSocket } from "@/features/websocket/use-tree-socket.ts";
 import { useNotificationSocket } from "@/features/notification/hooks/use-notification-socket.ts";
 import { useCollabToken } from "@/features/auth/queries/auth-query.tsx";
 import { Error404 } from "@/components/ui/error-404.tsx";
+import { OfflineFallback } from "@/features/offline/offline-fallback.tsx";
 import { queryClient } from "@/main.tsx";
 import { makeConnectHandler } from "@/features/user/connect-resync.ts";
 
@@ -70,14 +71,30 @@ export function UserProvider({ children }: React.PropsWithChildren) {
     document.documentElement.lang = i18n.resolvedLanguage || i18n.language || "en-US";
   }, [i18n.language, i18n.resolvedLanguage]);
 
-  if (isLoading) return <></>;
+  // First load with no cached user yet: render nothing briefly while the
+  // persisted ['currentUser'] cache hydrates (avoids flashing the offline
+  // fallback before restore). Once we have a user we render the app even if a
+  // refetch is still in flight.
+  if (isLoading && !data) return <></>;
 
   if (isError && error?.["response"]?.status === 404) {
     return <Error404 />;
   }
 
+  // We have a (possibly cached/stale) user — render the app. Offline, the
+  // POST /api/users/me refetch fails as a network error, but the persisted/
+  // hydrated user is enough to render the cached UI. Previously `if (error)
+  // return <></>` blanked every authenticated route on an offline reload even
+  // though the cached data was present (#237/#238).
+  if (data) {
+    return <>{children}</>;
+  }
+
+  // No user AND an error (offline cold boot of a page never warmed for offline,
+  // or no persisted cache to restore): show an explicit offline fallback rather
+  // than a blank white screen.
   if (error) {
-    return <></>;
+    return <OfflineFallback />;
   }
 
   return <>{children}</>;

apps/client/src/main.tsx

@@ -11,7 +11,8 @@ import { MantineProvider } from "@mantine/core";
 import { BrowserRouter } from "react-router-dom";
 import { ModalsProvider } from "@mantine/modals";
 import { Notifications } from "@mantine/notifications";
-import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+import { QueryClient } from "@tanstack/react-query";
+import { PersistQueryClientProvider } from "@tanstack/react-query-persist-client";
 import { HelmetProvider } from "react-helmet-async";
 import "./i18n";
 import { PostHogProvider } from "posthog-js/react";
@@ -21,6 +22,13 @@ import {
   isCloud,
   isPostHogEnabled,
 } from "@/lib/config.ts";
+import {
+  queryPersister,
+  shouldDehydrateOfflineQuery,
+} from "@/features/offline/query-persister";
+import { registerOfflineMutationDefaults } from "@/features/offline/offline-mutations";
+import { PwaUpdatePrompt } from "@/pwa/pwa-update-prompt";
+import { isCapacitorNativePlatform } from "@/pwa/is-capacitor";
 import posthog from "posthog-js";
 
 export const queryClient = new QueryClient({
@@ -30,10 +38,18 @@ export const queryClient = new QueryClient({
       refetchOnWindowFocus: false,
       retry: false,
       staleTime: 5 * 60 * 1000,
+      // Keep cached read data around long enough to be persisted/restored for offline use.
+      gcTime: 1000 * 60 * 60 * 24,
     },
   },
 });
 
+// Register default mutationFns for the offline-relevant structural mutations so
+// a paused mutation restored from IndexedDB after an offline reload still has a
+// mutationFn and is replayed by resumePausedMutations() on reconnect (instead
+// of silently no-op'ing and dropping the offline create/move/comment).
+registerOfflineMutationDefaults(queryClient);
+
 if (isCloud() && isPostHogEnabled) {
   posthog.init(getPostHogKey(), {
     api_host: getPostHogHost(),
@@ -50,15 +66,34 @@ root.render(
   <BrowserRouter>
     <MantineProvider theme={theme} cssVariablesResolver={mantineCssResolver}>
       <ModalsProvider>
-        <QueryClientProvider client={queryClient}>
+        <PersistQueryClientProvider
+          client={queryClient}
+          persistOptions={{
+            persister: queryPersister,
+            maxAge: 1000 * 60 * 60 * 24,
+            buster: APP_VERSION,
+            dehydrateOptions: {
+              shouldDehydrateQuery: shouldDehydrateOfflineQuery,
+            },
+          }}
+        >
           <Notifications position="bottom-center" limit={3} zIndex={10000} />
+          {/* Skip SW registration inside the Capacitor native WebView — the
+              native shell serves assets itself; a browser SW would conflict. */}
+          {!isCapacitorNativePlatform() && <PwaUpdatePrompt />}
           <HelmetProvider>
             <PostHogProvider client={posthog}>
               <App />
             </PostHogProvider>
           </HelmetProvider>
-        </QueryClientProvider>
+        </PersistQueryClientProvider>
       </ModalsProvider>
     </MantineProvider>
   </BrowserRouter>,
 );
+
+// Service worker registration is owned by <PwaUpdatePrompt /> above (via
+// vite-plugin-pwa's useRegisterSW: Workbox precache + prompt-based updates,
+// and skipped inside the Capacitor native WebView). The earlier hand-written
+// /sw.js registration from the mobile bootstrap was removed here to avoid a
+// double registration / competing service worker.

apps/client/src/pwa/is-capacitor.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect, afterEach } from "vitest";
+import { isCapacitorNativePlatform } from "./is-capacitor";
+
+describe("isCapacitorNativePlatform", () => {
+  afterEach(() => {
+    // Keep tests isolated from each other and from the rest of the suite.
+    delete (globalThis as any).Capacitor;
+  });
+
+  it("returns false when Capacitor is undefined", () => {
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("uses isNativePlatform() when it is a function", () => {
+    (globalThis as any).Capacitor = { isNativePlatform: () => true };
+    expect(isCapacitorNativePlatform()).toBe(true);
+
+    (globalThis as any).Capacitor = { isNativePlatform: () => false };
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("falls back to the boolean property when isNativePlatform is not a function", () => {
+    (globalThis as any).Capacitor = { isNativePlatform: true };
+    expect(isCapacitorNativePlatform()).toBe(true);
+
+    (globalThis as any).Capacitor = { isNativePlatform: false };
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+
+  it("returns false when reading Capacitor throws (try/catch)", () => {
+    Object.defineProperty(globalThis, "Capacitor", {
+      configurable: true,
+      get() {
+        throw new Error("boom");
+      },
+    });
+    expect(isCapacitorNativePlatform()).toBe(false);
+  });
+});

apps/client/src/pwa/is-capacitor.ts

@@ -0,0 +1,23 @@
+/**
+ * Detects whether the client is running inside a Capacitor native WebView
+ * (native iOS/Android shell from the feature/mobile-app-bootstrap branch).
+ *
+ * This is a pure runtime check against the global `Capacitor` object that the
+ * native bridge injects — no `@capacitor/*` dependency is added. On the plain
+ * browser / installed-PWA path `window.Capacitor` is undefined, so this returns
+ * false and the Workbox service worker registers normally.
+ *
+ * Inside the native WebView the SW must NOT register: it would layer a redundant
+ * (and conflicting) cache over Capacitor's own asset serving and interfere with
+ * the native auth/CORS flow.
+ */
+export function isCapacitorNativePlatform(): boolean {
+  try {
+    const cap = (globalThis as any)?.Capacitor;
+    return !!(cap && typeof cap.isNativePlatform === "function"
+      ? cap.isNativePlatform()
+      : cap?.isNativePlatform);
+  } catch {
+    return false;
+  }
+}

apps/client/src/pwa/pwa-update-prompt.tsx

@@ -0,0 +1,59 @@
+import { useEffect } from "react";
+import { Button } from "@mantine/core";
+import { notifications } from "@mantine/notifications";
+import { useTranslation } from "react-i18next";
+import { useRegisterSW } from "virtual:pwa-register/react";
+
+// Stable notification id so we can show/hide a single update prompt.
+const UPDATE_NOTIFICATION_ID = "pwa-update-available";
+
+/**
+ * Listens for a waiting service worker and surfaces a Mantine notification
+ * prompting the user to reload into the new version.
+ *
+ * Must be mounted inside the Mantine provider subtree (Notifications must be
+ * available). Renders nothing itself.
+ */
+export function PwaUpdatePrompt() {
+  const { t } = useTranslation();
+
+  const {
+    needRefresh: [needRefresh],
+    updateServiceWorker,
+  } = useRegisterSW({
+    onRegisterError(error) {
+      // Best-effort: a failed registration must not break the app.
+      console.error("Service worker registration error:", error);
+    },
+  });
+
+  useEffect(() => {
+    if (!needRefresh) return;
+
+    notifications.show({
+      id: UPDATE_NOTIFICATION_ID,
+      title: t("Update available"),
+      message: (
+        <Button
+          size="xs"
+          variant="light"
+          mt="xs"
+          onClick={() => updateServiceWorker(true)}
+        >
+          {t("Reload")}
+        </Button>
+      ),
+      autoClose: false,
+      withCloseButton: true,
+    });
+
+    // Hide the notification when the prompt is no longer needed / on cleanup.
+    return () => {
+      notifications.hide(UPDATE_NOTIFICATION_ID);
+    };
+  }, [needRefresh, t, updateServiceWorker]);
+
+  return null;
+}
+
+export default PwaUpdatePrompt;

apps/client/src/pwa/sw-strategy.test.ts

@@ -0,0 +1,32 @@
+import { describe, it, expect } from "vitest";
+import { isApiPath, isCollabOrSocketPath } from "./sw-strategy";
+
+describe("isApiPath", () => {
+  it("matches the /api segment and its subtree", () => {
+    expect(isApiPath("/api")).toBe(true);
+    expect(isApiPath("/api/")).toBe(true);
+    expect(isApiPath("/api/pages")).toBe(true);
+  });
+
+  it("does not over-match sibling paths", () => {
+    expect(isApiPath("/apidocs")).toBe(false);
+    expect(isApiPath("/apixyz")).toBe(false);
+    expect(isApiPath("/")).toBe(false);
+    expect(isApiPath("/pages")).toBe(false);
+  });
+});
+
+describe("isCollabOrSocketPath", () => {
+  it("matches the /collab and /socket.io segments and their subtrees", () => {
+    expect(isCollabOrSocketPath("/collab")).toBe(true);
+    expect(isCollabOrSocketPath("/collab/x")).toBe(true);
+    expect(isCollabOrSocketPath("/socket.io")).toBe(true);
+    expect(isCollabOrSocketPath("/socket.io/abc")).toBe(true);
+  });
+
+  it("does not over-match sibling paths", () => {
+    expect(isCollabOrSocketPath("/collaborators")).toBe(false);
+    expect(isCollabOrSocketPath("/collabx")).toBe(false);
+    expect(isCollabOrSocketPath("/socket.iox")).toBe(false);
+  });
+});

apps/client/src/pwa/sw-strategy.ts

@@ -0,0 +1,32 @@
+/**
+ * Canonical service-worker routing predicates.
+ *
+ * IMPORTANT: With vite-plugin-pwa using Workbox `generateSW`, the
+ * `runtimeCaching[].urlPattern` functions are serialized standalone into the
+ * generated service worker and CANNOT reference imported symbols. The matching
+ * logic is therefore duplicated as inline regex literals in
+ * apps/client/vite.config.ts. This module is the testable source of truth, and
+ * the two MUST be kept in sync. This duplication is intentional and is the
+ * documented Workbox limitation.
+ *
+ * Matching is anchored to a path SEGMENT boundary (`^/<seg>(/|$)`) so that
+ * sibling paths like `/apidocs`, `/collaborators`, `/socket.iox` are NOT
+ * wrongly treated as API/realtime traffic.
+ */
+
+/**
+ * True when `pathname` is the `/api` segment or anything beneath it.
+ * `/api` and `/api/...` -> true; `/apidocs`, `/apixyz` -> false.
+ */
+export function isApiPath(pathname: string): boolean {
+  return /^\/api(\/|$)/.test(pathname);
+}
+
+/**
+ * True when `pathname` is the `/collab` or `/socket.io` segment (or beneath it).
+ * `/collab`, `/collab/x`, `/socket.io`, `/socket.io/abc` -> true;
+ * `/collaborators`, `/collabx`, `/socket.iox` -> false.
+ */
+export function isCollabOrSocketPath(pathname: string): boolean {
+  return /^\/(collab|socket\.io)(\/|$)/.test(pathname);
+}

apps/client/src/vite-env.d.ts

@@ -1,2 +1,4 @@
 /// <reference types="vite/client" />
+/// <reference types="vite-plugin-pwa/react" />
+/// <reference types="vite-plugin-pwa/info" />
 declare const APP_VERSION: string

apps/client/vite.config.ts

@@ -1,5 +1,6 @@
 import { defineConfig, loadEnv } from "vite";
 import react from "@vitejs/plugin-react";
+import { VitePWA } from "vite-plugin-pwa";
 import * as path from "path";
 import { execSync } from "node:child_process";
 
@@ -53,7 +54,51 @@ export default defineConfig(({ mode }) => {
       },
       APP_VERSION: JSON.stringify(resolveAppVersion(envPath)),
     },
-    plugins: [react()],
+    plugins: [
+      react(),
+      VitePWA({
+        registerType: "prompt",
+        injectRegister: null,
+        strategies: "generateSW",
+        manifest: false,
+        workbox: {
+          globPatterns: ["**/*.{js,css,html,svg,png,ico,woff2,json}"],
+          navigateFallback: "index.html",
+          // Segment-anchored (`^/<seg>(/|$)`) so navigation requests to these
+          // segments are consistently excluded from the SPA fallback, mirroring
+          // the runtimeCaching urlPattern regexes below.
+          //
+          // `/share`, `/mcp`, and `/robots.txt` mirror the server static-serve
+          // exclude list (apps/server/src/main.ts setGlobalPrefix `exclude`):
+          // robots.txt, the SEO/OG/analytics-injected public share HTML, and the
+          // embedded MCP endpoint are served by server controllers, so the SW must
+          // never shadow them with the precached index.html app shell (doing so
+          // would break SEO and MCP).
+          navigateFallbackDenylist: [
+            /^\/api(\/|$)/,
+            /^\/collab(\/|$)/,
+            /^\/socket\.io(\/|$)/,
+            /^\/share(\/|$)/,
+            /^\/mcp(\/|$)/,
+            /^\/robots\.txt$/,
+          ],
+          cleanupOutdatedCaches: true,
+          clientsClaim: true,
+          // The urlPattern regexes below mirror apps/client/src/pwa/sw-strategy.ts
+          // and MUST be kept in sync with it. Workbox `generateSW` serializes these
+          // functions standalone into the generated service worker, so they cannot
+          // import the module — the matching logic is intentionally duplicated as
+          // self-contained inline regex literals anchored to a path segment boundary.
+          runtimeCaching: [
+            { urlPattern: ({ url }) => /^\/(collab|socket\.io)(\/|$)/.test(url.pathname), handler: "NetworkOnly" },
+            // All /api stays network-only; offline reads come from the persisted
+            // React Query cache (IndexedDB) + y-indexeddb, not the SW HTTP cache.
+            { urlPattern: ({ url }) => /^\/api(\/|$)/.test(url.pathname), handler: "NetworkOnly" },
+          ],
+        },
+        devOptions: { enabled: false },
+      }),
+    ],
     build: {
       rolldownOptions: {
         output: {

apps/server/package.json

@@ -64,6 +64,7 @@
     "@nestjs/platform-fastify": "^11.1.19",
     "@nestjs/platform-socket.io": "^11.1.19",
     "@nestjs/schedule": "^6.1.3",
+    "@nestjs/swagger": "^11.2.0",
     "@nestjs/terminus": "^11.1.1",
     "@nestjs/throttler": "^6.5.0",
     "@nestjs/websockets": "^11.1.19",

apps/server/src/collaboration/collaboration.gateway.ts

@@ -24,7 +24,9 @@ import { CollabWsAdapter } from './adapter/collab-ws.adapter';
 import {
   CollaborationHandler,
   CollabEventHandlers,
+  writeTitleFragment,
 } from './collaboration.handler';
+import { User } from '@docmost/db/types/entity.types';
 
 @Injectable()
 export class CollaborationGateway {
@@ -149,6 +151,45 @@ export class CollaborationGateway {
     return this.hocuspocus.openDirectConnection(documentName, context);
   }
 
+  /**
+   * Write a new page title INTO the page's Yjs 'title' fragment, Redis-INDEPENDENT.
+   *
+   * Unlike the Redis-routed `handleYjsEvent` path — which routes through
+   * `redisSync?.handleEvent` and SILENTLY no-ops when Redis is disabled
+   * (COLLAB_DISABLE_REDIS=true → redisSync === null) — this goes straight
+   * through the local Hocuspocus `openDirectConnection`. The title sync
+   * therefore works in BOTH single-process (no Redis) and Redis-clustered
+   * deployments.
+   *
+   * openDirectConnection loads the doc from persistence when no editor is
+   * connected, so this works whether or not an editor is currently open: the
+   * clear+reseed lands on the loaded doc and is persisted by onStoreDocument.
+   *
+   * Provenance: when the caller is the agent, the actor/aiChatId are threaded
+   * into the connection `context` so onStoreDocument sees `context.actor ===
+   * 'agent'` for the resulting title store (mirrors the body/REST path). The
+   * resulting title store is usually a no-op anyway — PageService already wrote
+   * the same title to the page.title column, so onStoreDocument's
+   * `titleText !== page.title` guard skips the column write — but we wire the
+   * context for correctness regardless.
+   */
+  async writePageTitle(
+    pageId: string,
+    title: string,
+    context?: { user?: User; actor?: string; aiChatId?: string },
+  ): Promise<void> {
+    const documentName = `page.${pageId}`;
+    const connection = await this.hocuspocus.openDirectConnection(
+      documentName,
+      context ?? {},
+    );
+    try {
+      await connection.transact((doc) => writeTitleFragment(doc, title));
+    } finally {
+      await connection.disconnect();
+    }
+  }
+
   /*
    *Can be used before calling openDirectConnection directly
    */

apps/server/src/collaboration/collaboration.handler.spec.ts

@@ -0,0 +1,139 @@
+import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { writeTitleFragment } from './collaboration.handler';
+import { CollaborationGateway } from './collaboration.gateway';
+import {
+  buildTitleSeedYdoc,
+  jsonToText,
+  tiptapExtensions,
+} from './collaboration.util';
+
+// Read the plain text held in the doc's 'title' XmlFragment, the same way
+// PersistenceExtension.onStoreDocument extracts it before writing page.title.
+const readTitleText = (doc: Y.Doc): string => {
+  const titleJson = TiptapTransformer.fromYdoc(doc, 'title');
+  return titleJson ? jsonToText(titleJson).trim() : '';
+};
+
+describe('writeTitleFragment — the clear+seed title write (Bug 1)', () => {
+  it('replaces an OLD title fragment with EXACTLY the new title (no duplication)', () => {
+    // Seed the doc's 'title' fragment with an OLD title, like a real page.
+    const doc = new Y.Doc();
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old Title')));
+    expect(readTitleText(doc)).toBe('Old Title');
+
+    writeTitleFragment(doc, 'New Title');
+
+    // The fragment must contain EXACTLY the new title — not "Old TitleNew Title"
+    // (append) or "New TitleNew Title" (duplication). A single heading node.
+    expect(readTitleText(doc)).toBe('New Title');
+
+    const titleJson = TiptapTransformer.fromYdoc(doc, 'title') as any;
+    expect(titleJson.content).toHaveLength(1);
+    expect(titleJson.content[0].type).toBe('heading');
+  });
+
+  it('seeds the title fragment when it started empty', () => {
+    const doc = new Y.Doc();
+    // Force the 'title' fragment to exist but be empty.
+    doc.getXmlFragment('title');
+    expect(readTitleText(doc)).toBe('');
+
+    writeTitleFragment(doc, 'First Title');
+
+    expect(readTitleText(doc)).toBe('First Title');
+  });
+
+  it('does not corrupt the body when rewriting the title', () => {
+    // A doc with both a body and an old title; the body must survive untouched.
+    const doc = new Y.Doc();
+    const bodyDoc = TiptapTransformer.toYdoc(
+      {
+        type: 'doc',
+        content: [
+          { type: 'paragraph', content: [{ type: 'text', text: 'body text' }] },
+        ],
+      },
+      'default',
+      tiptapExtensions,
+    );
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(bodyDoc));
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old')));
+
+    writeTitleFragment(doc, 'New');
+
+    expect(readTitleText(doc)).toBe('New');
+    const bodyJson = TiptapTransformer.fromYdoc(doc, 'default');
+    expect(jsonToText(bodyJson)).toContain('body text');
+  });
+});
+
+describe('CollaborationGateway.writePageTitle — Redis-independent path', () => {
+  // Build a gateway with only its hocuspocus.openDirectConnection stubbed; the
+  // method must drive the clear+seed through that direct connection (NOT through
+  // redisSync), so the title write survives COLLAB_DISABLE_REDIS.
+  const makeGateway = (doc: Y.Doc) => {
+    const disconnect = jest.fn().mockResolvedValue(undefined);
+    const transact = jest.fn(async (fn: (d: Y.Doc) => void) => {
+      fn(doc);
+    });
+    const openDirectConnection = jest
+      .fn()
+      .mockResolvedValue({ transact, disconnect });
+
+    const gateway = Object.create(CollaborationGateway.prototype);
+    // redisSync is intentionally null — this is the no-Redis scenario.
+    gateway.redisSync = null;
+    gateway.hocuspocus = { openDirectConnection } as any;
+
+    return { gateway, openDirectConnection, transact, disconnect };
+  };
+
+  it('writes the new title via openDirectConnection and disconnects', async () => {
+    const doc = new Y.Doc();
+    Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Old Title')));
+
+    const { gateway, openDirectConnection, disconnect } = makeGateway(doc);
+
+    await gateway.writePageTitle('page-1', 'New Title', { user: { id: 'u1' } });
+
+    expect(openDirectConnection).toHaveBeenCalledWith(
+      'page.page-1',
+      expect.objectContaining({ user: { id: 'u1' } }),
+    );
+    expect(readTitleText(doc)).toBe('New Title');
+    expect(disconnect).toHaveBeenCalledTimes(1);
+  });
+
+  it('threads agent provenance into the connection context', async () => {
+    const doc = new Y.Doc();
+    const { gateway, openDirectConnection } = makeGateway(doc);
+
+    await gateway.writePageTitle('page-1', 'Agent Title', {
+      user: { id: 'u1' },
+      actor: 'agent',
+      aiChatId: 'chat-1',
+    });
+
+    expect(openDirectConnection).toHaveBeenCalledWith(
+      'page.page-1',
+      expect.objectContaining({ actor: 'agent', aiChatId: 'chat-1' }),
+    );
+  });
+
+  it('disconnects even when the transaction throws', async () => {
+    const disconnect = jest.fn().mockResolvedValue(undefined);
+    const openDirectConnection = jest.fn().mockResolvedValue({
+      transact: jest.fn().mockRejectedValue(new Error('boom')),
+      disconnect,
+    });
+    const gateway = Object.create(CollaborationGateway.prototype);
+    gateway.redisSync = null;
+    gateway.hocuspocus = { openDirectConnection } as any;
+
+    await expect(
+      gateway.writePageTitle('page-1', 'X', {}),
+    ).rejects.toThrow('boom');
+    expect(disconnect).toHaveBeenCalledTimes(1);
+  });
+});

apps/server/src/collaboration/collaboration.handler.ts

@@ -2,6 +2,7 @@ import { Injectable, Logger } from '@nestjs/common';
 import { Hocuspocus, Document } from '@hocuspocus/server';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
+  buildTitleSeedYdoc,
   prosemirrorNodeToYElement,
   tiptapExtensions,
 } from './collaboration.util';
@@ -13,6 +14,35 @@ export type CollabEventHandlers = ReturnType<
   CollaborationHandler['getHandlers']
 >;
 
+/**
+ * Clear+reseed the 'title' XmlFragment of `doc` so it holds EXACTLY `title`.
+ *
+ * Used by the gateway's direct `writePageTitle` method to write a new page
+ * title INTO the page's Yjs 'title' fragment. The title lives in the same
+ * Y.Doc as the body; onStoreDocument extracts it on every save, so a REST/MCP
+ * rename that only updated the page.title DB column would be reverted on the
+ * next collaborative save unless the Yjs 'title' fragment is kept in sync.
+ * The whole fragment is replaced (no merge/append),
+ * mirroring the 'replace' body path: the new title fully supersedes the old.
+ *
+ * DELIBERATE TRADE-OFF: because this does a FULL clear+replace of the 'title'
+ * fragment, a REST/MCP rename arriving while a user is actively editing the
+ * title in an open editor WILL overwrite that in-progress edit. This is
+ * acceptable — the title is a short, rarely-concurrently-edited field — and is
+ * preferable to leaving a stale Yjs title that onStoreDocument would revert the
+ * DB column to on the next save.
+ */
+export function writeTitleFragment(doc: Y.Doc, title: string): void {
+  const titleFragment = doc.getXmlFragment('title');
+
+  if (titleFragment.length > 0) {
+    titleFragment.delete(0, titleFragment.length);
+  }
+
+  const newTitleDoc = buildTitleSeedYdoc(title);
+  Y.applyUpdate(doc, Y.encodeStateAsUpdate(newTitleDoc));
+}
+
 @Injectable()
 export class CollaborationHandler {
   private readonly logger = new Logger(CollaborationHandler.name);

apps/server/src/collaboration/collaboration.util.spec.ts

@@ -1,9 +1,12 @@
 import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
   getPageId,
   isEmptyParagraphDoc,
   jsonToNode,
   prosemirrorNodeToYElement,
+  buildTitleSeedYdoc,
+  jsonToText,
 } from './collaboration.util';
 import { Node } from '@tiptap/pm/model';
 
@@ -241,3 +244,43 @@ describe('prosemirrorNodeToYElement', () => {
     expect(element.get(1).get(0).toString()).toBe('two');
   });
 });
+
+describe('buildTitleSeedYdoc', () => {
+  it('builds a level-1 heading carrying the title text', () => {
+    const doc = buildTitleSeedYdoc('Hello World');
+    const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+
+    const first = json.content?.[0];
+    expect(first.type).toBe('heading');
+    expect(first.attrs.level).toBe(1);
+    expect(jsonToText(json).trim()).toBe('Hello World');
+  });
+
+  it('produces a non-empty title fragment for a non-empty title', () => {
+    const doc = buildTitleSeedYdoc('Some Title');
+    expect(doc.get('title', Y.XmlFragment).length).toBeGreaterThan(0);
+  });
+
+  it('produces a heading with no text child for an empty title', () => {
+    const doc = buildTitleSeedYdoc('');
+    const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+
+    const first = json.content?.[0];
+    expect(first.type).toBe('heading');
+    // No text content for an empty title.
+    expect(first.content ?? []).toHaveLength(0);
+    expect(jsonToText(json).trim()).toBe('');
+  });
+
+  it('round-trips a title through build -> extract -> build -> extract', () => {
+    const title = 'Round Trip Title';
+    const doc1 = buildTitleSeedYdoc(title);
+    const text1 = jsonToText(TiptapTransformer.fromYdoc(doc1, 'title')).trim();
+
+    const doc2 = buildTitleSeedYdoc(text1);
+    const text2 = jsonToText(TiptapTransformer.fromYdoc(doc2, 'title')).trim();
+
+    expect(text1).toBe(title);
+    expect(text2).toBe(text1);
+  });
+});

apps/server/src/collaboration/collaboration.util.ts

@@ -59,6 +59,7 @@ import { generateHTML, generateJSON } from '../common/helpers/prosemirror/html';
 import { Node, Schema } from '@tiptap/pm/model';
 import * as Y from 'yjs';
 import { Logger } from '@nestjs/common';
+import { TiptapTransformer } from '@hocuspocus/transformer';
 
 export const tiptapExtensions = [
   StarterKit.configure({
@@ -143,6 +144,34 @@ export function jsonToText(tiptapJson: JSONContent) {
   return generateText(tiptapJson, tiptapExtensions);
 }
 
+/**
+ * Build a standalone Y.Doc that holds ONLY the page title, in a dedicated Yjs
+ * fragment named exactly 'title' (the collaborative title-editor contract with
+ * the client). The ProseMirror shape is a doc with a single level-1 heading
+ * whose text is the title (empty title => heading with no text child).
+ *
+ * The encoded state of the returned doc can be merged into a body doc via
+ * `Y.applyUpdate(doc, Y.encodeStateAsUpdate(titleSeed))` to seed the title
+ * fragment for legacy pages. Seeding MUST be guarded by an emptiness check on
+ * the existing 'title' fragment to avoid the Yjs duplication trap.
+ */
+export function buildTitleSeedYdoc(title: string): Y.Doc {
+  return TiptapTransformer.toYdoc(
+    {
+      type: 'doc',
+      content: [
+        {
+          type: 'heading',
+          attrs: { level: 1 },
+          content: title ? [{ type: 'text', text: title }] : [],
+        },
+      ],
+    },
+    'title',
+    tiptapExtensions,
+  );
+}
+
 export function jsonToNode(tiptapJson: JSONContent) {
   const schema = getSchema(tiptapExtensions);
   try {

apps/server/src/collaboration/constants.ts

@@ -1,3 +1,9 @@
 export const HISTORY_INTERVAL = 5 * 60 * 1000;
 export const HISTORY_FAST_INTERVAL = 60 * 1000;
 export const HISTORY_FAST_THRESHOLD = 5 * 60 * 1000;
+
+// Redis pub/sub channel that bridges a PAGE_UPDATED tree snapshot (a title/icon
+// rename) from the standalone collab process to the API process, which is the
+// single broadcast authority. Imported by both halves of the bridge:
+// PageTreeBridgePublisher (collab process) and PageTreeBridgeSubscriber (API process).
+export const COLLAB_TREE_UPDATE_CHANNEL = 'collab:tree-update';

apps/server/src/collaboration/extensions/persistence.extension.spec.ts

@@ -0,0 +1,483 @@
+import * as Y from 'yjs';
+import { TiptapTransformer } from '@hocuspocus/transformer';
+import { PersistenceExtension } from './persistence.extension';
+import { buildTitleSeedYdoc, tiptapExtensions } from '../collaboration.util';
+
+// Direct instantiation with stub deps, mirroring the auth/env unit specs.
+const bodyJson = {
+  type: 'doc',
+  content: [{ type: 'paragraph', content: [{ type: 'text', text: 'hello' }] }],
+};
+
+// Build a body Y.Doc with a known JSON, plus a monkey-patched broadcastStateless
+// (the real Hocuspocus Document supplies it; a bare Y.Doc does not).
+const buildDoc = () => {
+  const d: any = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+  d.broadcastStateless = jest.fn();
+  return d;
+};
+
+const cloneOut = (doc: any) =>
+  JSON.parse(JSON.stringify(TiptapTransformer.fromYdoc(doc, 'default')));
+
+const addTitleFragment = (doc: any, title: string) =>
+  Y.applyUpdate(doc, Y.encodeStateAsUpdate(buildTitleSeedYdoc(title)));
+
+describe('PersistenceExtension', () => {
+  let pageRepo: any;
+  let pageHistoryRepo: any;
+  let trx: any;
+  let db: any;
+  let aiQueue: any;
+  let historyQueue: any;
+  let notificationQueue: any;
+  let collabHistory: any;
+  let transclusionService: any;
+  let ext: PersistenceExtension;
+
+  beforeEach(() => {
+    pageRepo = {
+      findById: jest.fn(),
+      updatePage: jest.fn().mockResolvedValue(undefined),
+    };
+    pageHistoryRepo = {
+      findPageLastHistory: jest.fn(),
+      saveHistory: jest.fn(),
+    };
+    trx = {};
+    db = { transaction: () => ({ execute: (fn: any) => fn(trx) }) };
+    aiQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    historyQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    notificationQueue = { add: jest.fn().mockResolvedValue(undefined) };
+    collabHistory = { addContributors: jest.fn().mockResolvedValue(undefined) };
+    transclusionService = {
+      syncPageTransclusions: jest.fn().mockResolvedValue(undefined),
+      syncPageReferences: jest.fn().mockResolvedValue(undefined),
+      syncPageTemplateReferences: jest.fn().mockResolvedValue(undefined),
+    };
+
+    ext = new PersistenceExtension(
+      pageRepo as any,
+      pageHistoryRepo as any,
+      db as any,
+      aiQueue as any,
+      historyQueue as any,
+      notificationQueue as any,
+      collabHistory as any,
+      transclusionService as any,
+    );
+  });
+
+  describe('seedTitleFragment', () => {
+    it('returns false for empty/whitespace/null titles', () => {
+      const doc = new Y.Doc();
+      expect((ext as any).seedTitleFragment(doc, '')).toBe(false);
+      expect((ext as any).seedTitleFragment(doc, '   ')).toBe(false);
+      expect((ext as any).seedTitleFragment(doc, null)).toBe(false);
+    });
+
+    it('does NOT re-seed an existing non-empty title fragment', () => {
+      const doc = new Y.Doc();
+      addTitleFragment(doc, 'Existing');
+
+      expect((ext as any).seedTitleFragment(doc, 'Other')).toBe(false);
+
+      const text = TiptapTransformer.fromYdoc(doc, 'title');
+      expect(JSON.stringify(text)).toContain('Existing');
+      expect(JSON.stringify(text)).not.toContain('Other');
+    });
+
+    it('seeds an empty fragment from a non-empty title and returns true', () => {
+      const doc = new Y.Doc();
+      expect((ext as any).seedTitleFragment(doc, 'Hello')).toBe(true);
+
+      const json: any = TiptapTransformer.fromYdoc(doc, 'title');
+      expect(JSON.stringify(json)).toContain('Hello');
+    });
+
+    it('returns false (defensive) when reading the fragment throws', () => {
+      const fakeDoc = {
+        get: () => {
+          throw new Error('boom');
+        },
+      };
+      expect((ext as any).seedTitleFragment(fakeDoc as any, 'X')).toBe(false);
+    });
+  });
+
+  describe('onStoreDocument', () => {
+    const basePage = (overrides: any) => ({
+      id: 'PAGE_ID',
+      slugId: 'slug',
+      spaceId: 'space',
+      parentPageId: null,
+      creatorId: 'creator',
+      contributorIds: ['creator'],
+      workspaceId: 'ws',
+      title: 'whatever',
+      content: null,
+      lastUpdatedSource: 'user',
+      createdAt: new Date().toISOString(),
+      ...overrides,
+    });
+
+    const context = { user: { id: 'u1', name: 'U', avatarUrl: null } };
+
+    it('no-op when neither body nor title changed', async () => {
+      const document = buildDoc();
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'hello title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(document.broadcastStateless).not.toHaveBeenCalled();
+      expect(collabHistory.addContributors).not.toHaveBeenCalled();
+      expect(transclusionService.syncPageTransclusions).not.toHaveBeenCalled();
+      expect(aiQueue.add).not.toHaveBeenCalled();
+      expect(historyQueue.add).not.toHaveBeenCalled();
+    });
+
+    it('title-only change persists the title without body side-effects', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, 'New Title');
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'Old Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].title).toBe('New Title');
+      expect(call[0].ydoc).toBeDefined();
+      expect(call[0].contributorIds).toBeDefined();
+      expect('content' in call[0]).toBe(false);
+      // Title-only must not touch the body-authorship provenance.
+      expect('lastUpdatedSource' in call[0]).toBe(false);
+      expect(call[1]).toBe('PAGE_ID');
+      expect(call[3].treeUpdate.title).toBe('New Title');
+
+      expect(collabHistory.addContributors).toHaveBeenCalledTimes(1);
+      expect(collabHistory.addContributors).toHaveBeenCalledWith(
+        'PAGE_ID',
+        expect.any(Array),
+      );
+      expect(document.broadcastStateless).toHaveBeenCalledTimes(1);
+      expect(transclusionService.syncPageTransclusions).not.toHaveBeenCalled();
+      expect(aiQueue.add).not.toHaveBeenCalled();
+      expect(historyQueue.add).not.toHaveBeenCalled();
+    });
+
+    it('an EMPTY title fragment does NOT overwrite a non-empty page.title (anti-corruption guard, Bug 2)', async () => {
+      // The client can momentarily seed the 'title' fragment as an EMPTY heading
+      // (hasTitleFragment true, extracted text '') before the real title syncs.
+      // Body is unchanged here, so the only candidate write is the title -> the
+      // guard must turn this into a full no-op (no updatePage, no broadcast).
+      const document = buildDoc();
+      addTitleFragment(document, ''); // empty heading: length > 0 but text ''
+      const page = basePage({
+        content: cloneOut(document),
+        title: 'Real Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      // No write at all: the empty title is not authoritative and the body is
+      // unchanged, so onStoreDocument must take the no-op fast path.
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(document.broadcastStateless).not.toHaveBeenCalled();
+    });
+
+    it('an EMPTY title fragment alongside a body change persists the body but NOT an empty title (anti-corruption guard, Bug 2)', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, ''); // empty title fragment
+      const page = basePage({
+        content: { type: 'doc', content: [] }, // different body -> bodyChanged
+        title: 'Real Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      // Body is persisted, but the title is NOT included (empty == not
+      // authoritative) and no tree update is broadcast for the title.
+      expect(call[0].content).toBeTruthy();
+      expect('title' in call[0]).toBe(false);
+      expect(call[3]).toBeUndefined();
+    });
+
+    it('body + title change persists both with full body side-effects', async () => {
+      const document = buildDoc();
+      addTitleFragment(document, 'New Title');
+      const page = basePage({
+        content: { type: 'doc', content: [] },
+        title: 'Old Title',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].content).toBeTruthy();
+      expect(call[0].title).toBe('New Title');
+      expect(call[0].ydoc).toBeDefined();
+      expect(call[0].lastUpdatedSource).toBe('user');
+      expect(call[3].treeUpdate).toBeDefined();
+
+      expect(transclusionService.syncPageTransclusions).toHaveBeenCalled();
+      expect(aiQueue.add).toHaveBeenCalled();
+      expect(historyQueue.add).toHaveBeenCalled();
+      expect(collabHistory.addContributors).toHaveBeenCalled();
+      expect(document.broadcastStateless).toHaveBeenCalled();
+    });
+
+    it('body-only change persists the body without a tree update', async () => {
+      const document = buildDoc();
+      const page = basePage({
+        content: { type: 'doc', content: [] },
+        title: 'whatever',
+      });
+      pageRepo.findById.mockResolvedValue(page);
+
+      await ext.onStoreDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+        context,
+      } as any);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(call[0].content).toBeTruthy();
+      expect('title' in call[0]).toBe(false);
+      // No treeUpdate for a body-only save.
+      expect(call[3]).toBeUndefined();
+
+      expect(transclusionService.syncPageTransclusions).toHaveBeenCalled();
+      expect(aiQueue.add).toHaveBeenCalled();
+      expect(historyQueue.add).toHaveBeenCalled();
+      expect(document.broadcastStateless).toHaveBeenCalled();
+    });
+  });
+
+  describe('onLoadDocument', () => {
+    it('returns early (no DB read) when the document is not empty', async () => {
+      const document = { isEmpty: () => false };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      expect(result).toBeUndefined();
+      expect(pageRepo.findById).not.toHaveBeenCalled();
+    });
+
+    it('returns undefined and does not persist when the page is null', async () => {
+      const document = { isEmpty: () => true };
+      pageRepo.findById.mockResolvedValue(null);
+
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      expect(result).toBeUndefined();
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+    });
+
+    it('seeds + persists under a lock when the persisted ydoc lacks a title fragment', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Legacy Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      // Both the cheap pre-check and the locked re-read return the same row.
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // The locked re-read must take the row lock inside the tx.
+      const lockedReadCall = pageRepo.findById.mock.calls.find(
+        (c: any[]) => c[1]?.withLock,
+      );
+      expect(lockedReadCall).toBeDefined();
+      expect(lockedReadCall[1].trx).toBe(trx);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(Buffer.isBuffer(call[0].ydoc)).toBe(true);
+      expect(call[1]).toBe('PAGE_ID');
+      // Persist must run inside the transaction.
+      expect(call[2]).toBe(trx);
+      expect(result).toBeTruthy();
+    });
+
+    it('does NOT lock or persist when the ydoc already has a title fragment', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      Y.applyUpdate(src, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Has Title')));
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Has Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // Hot path: only the cheap lock-free read, no locked re-read, no write.
+      expect(pageRepo.findById).toHaveBeenCalledTimes(1);
+      expect(pageRepo.findById.mock.calls[0][1]?.withLock).toBeFalsy();
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      expect(result).toBeTruthy();
+    });
+
+    it('converts legacy content -> ydoc inside a tx and persists a {ydoc} Buffer', async () => {
+      const page = {
+        id: 'PAGE_ID',
+        title: 'T',
+        ydoc: null,
+        content: bodyJson,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      const lockedReadCall = pageRepo.findById.mock.calls.find(
+        (c: any[]) => c[1]?.withLock,
+      );
+      expect(lockedReadCall).toBeDefined();
+      expect(lockedReadCall[1].trx).toBe(trx);
+
+      expect(pageRepo.updatePage).toHaveBeenCalledTimes(1);
+      const call = pageRepo.updatePage.mock.calls[0];
+      expect(Buffer.isBuffer(call[0].ydoc)).toBe(true);
+      expect(call[2]).toBe(trx);
+      // The rebuilt doc carries the body.
+      expect(JSON.stringify(cloneOut(result))).toContain('hello');
+    });
+
+    it('SKIPS rebuild when the locked re-read shows the ydoc was already healed', async () => {
+      // Simulate a concurrent process: the cheap pre-check sees ydoc=null (legacy
+      // rebuild path), but by the time we hold the lock another process has
+      // already persisted a healthy ydoc. We must adopt it, not rebuild/clobber.
+      const healed = TiptapTransformer.toYdoc(
+        { type: 'doc', content: [{ type: 'paragraph', content: [{ type: 'text', text: 'healed' }] }] },
+        'default',
+        tiptapExtensions,
+      );
+      Y.applyUpdate(healed, Y.encodeStateAsUpdate(buildTitleSeedYdoc('Healed Title')));
+      const healedYdoc = Buffer.from(Y.encodeStateAsUpdate(healed));
+
+      const preCheck = { id: 'PAGE_ID', title: 'T', ydoc: null, content: bodyJson };
+      const lockedRow = {
+        id: 'PAGE_ID',
+        title: 'Healed Title',
+        ydoc: healedYdoc,
+        content: bodyJson,
+      };
+      pageRepo.findById
+        .mockResolvedValueOnce(preCheck) // cheap pre-check
+        .mockResolvedValueOnce(lockedRow); // locked re-read
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // The healthy ydoc had a title fragment already, so nothing was rebuilt or
+      // seeded -> no clobbering write.
+      expect(pageRepo.updatePage).not.toHaveBeenCalled();
+      // The returned doc is the healed body, NOT a fresh rebuild of bodyJson.
+      expect(JSON.stringify(cloneOut(result))).toContain('healed');
+    });
+
+    it('REJECTS the load when the rebuild persist fails (does not return an unpersisted doc)', async () => {
+      const page = { id: 'PAGE_ID', title: 'T', ydoc: null, content: bodyJson };
+      pageRepo.findById.mockResolvedValue(page);
+      pageRepo.updatePage.mockRejectedValue(new Error('db down'));
+      const errSpy = jest
+        .spyOn((ext as any).logger, 'error')
+        .mockImplementation(() => undefined);
+
+      const document = { isEmpty: () => true };
+      await expect(
+        ext.onLoadDocument({
+          documentName: 'page.PAGE_ID',
+          document,
+        } as any),
+      ).rejects.toThrow('db down');
+      expect(errSpy).toHaveBeenCalled();
+    });
+
+    it('seed-only persist FAILURE returns the doc from the existing ydoc (no throw)', async () => {
+      const src = TiptapTransformer.toYdoc(bodyJson, 'default', tiptapExtensions);
+      const page = {
+        id: 'PAGE_ID',
+        title: 'Legacy Title',
+        ydoc: Buffer.from(Y.encodeStateAsUpdate(src)),
+        content: null,
+      };
+      pageRepo.findById.mockResolvedValue(page);
+      pageRepo.updatePage.mockRejectedValue(new Error('db down'));
+      const errSpy = jest
+        .spyOn((ext as any).logger, 'error')
+        .mockImplementation(() => undefined);
+
+      const document = { isEmpty: () => true };
+      const result = await ext.onLoadDocument({
+        documentName: 'page.PAGE_ID',
+        document,
+      } as any);
+
+      // Non-fatal: we fall back to the doc loaded from the existing page.ydoc.
+      expect(result).toBeTruthy();
+      expect(JSON.stringify(cloneOut(result))).toContain('hello');
+      expect(errSpy).toHaveBeenCalled();
+    });
+  });
+});

apps/server/src/collaboration/extensions/persistence.extension.ts

@@ -9,6 +9,7 @@ import * as Y from 'yjs';
 import { Injectable, Logger } from '@nestjs/common';
 import { TiptapTransformer } from '@hocuspocus/transformer';
 import {
+  buildTitleSeedYdoc,
   getPageId,
   isEmptyParagraphDoc,
   jsonToText,
@@ -116,6 +117,10 @@ export class PersistenceExtension implements Extension {
       return;
     }
 
+    // Cheap, lock-free pre-check (hot path stays lock-free). It tells us whether
+    // any heal (legacy rebuild and/or title seed) is needed; the heal itself
+    // re-reads the row FOR UPDATE and re-validates inside a transaction so it
+    // runs exactly once (see healUnderLock).
     const page = await this.pageRepo.findById(pageId, {
       includeContent: true,
       includeYdoc: true,
@@ -127,33 +132,164 @@ export class PersistenceExtension implements Extension {
     }
 
     if (page.ydoc) {
-      this.logger.debug(`ydoc loaded from db: ${pageId}`);
-
       const doc = new Y.Doc();
-      const dbState = new Uint8Array(page.ydoc);
+      Y.applyUpdate(doc, new Uint8Array(page.ydoc));
 
-      Y.applyUpdate(doc, dbState);
-      return doc;
+      // Legacy pages persisted their title only in the `page.title` column; the
+      // ydoc has no 'title' fragment. Decide cheaply (no lock) whether a seed is
+      // needed by inspecting the loaded doc's 'title' fragment. A seed is needed
+      // only when that fragment is empty AND there is a non-empty column title.
+      let titleSeedNeeded = false;
+      try {
+        const titleFrag = doc.get('title', Y.XmlFragment);
+        titleSeedNeeded = titleFrag.length === 0 && !!page.title?.trim();
+      } catch (err) {
+        // A malformed title fragment must not break loading; skip the seed.
+        this.logger.warn(`failed to inspect title fragment: ${err?.['message']}`);
+        titleSeedNeeded = false;
+      }
+
+      if (!titleSeedNeeded) {
+        // Fully healthy: a ydoc with a title fragment (or nothing to seed).
+        this.logger.debug(`ydoc loaded from db: ${pageId}`);
+        return doc;
+      }
+
+      // SEED-ONLY heal: a valid page.ydoc already exists; we only need to add the
+      // title fragment. If the persist fails we must NOT hand out an unpersisted
+      // fresh-client-id seed (it could later duplicate the title), so we fall
+      // back to the healthy doc loaded from the EXISTING page.ydoc, without the
+      // seed. The title just won't render until a later successful heal —
+      // non-fatal, non-corrupting.
+      try {
+        return await this.healUnderLock(pageId);
+      } catch (err) {
+        this.logger.error(
+          `Failed to persist seeded ydoc for page ${pageId}; serving existing ydoc without title seed`,
+          err,
+        );
+        return doc;
+      }
     }
 
-    // if no ydoc state in db convert json in page.content to Ydoc.
+    // NOTE (offline-sync M1, Goal 2): this per-load self-heal converts +
+    // title-seeds + persists every legacy page (content set, ydoc null) on its
+    // first open, which neutralizes the duplication trap incrementally. A
+    // proactive one-shot BATCH migration over all such pages could be added
+    // later, but it requires the tiptap schema + TiptapTransformer (Node/Yjs),
+    // which a Kysely SQL migration cannot run; no runnable-task/CLI convention
+    // exists in this repo yet, so we deliberately avoid a fragile migration.
+    //
+    // If no ydoc state in db, REBUILD a Y.Doc from the JSON in page.content under
+    // a row lock (see healUnderLock).
     if (page.content) {
-      this.logger.debug(`converting json to ydoc: ${pageId}`);
-
-      const ydoc = TiptapTransformer.toYdoc(
-        page.content,
-        'default',
-        tiptapExtensions,
-      );
-
-      Y.encodeStateAsUpdate(ydoc);
-      return ydoc;
+      // REBUILD heal: surface failures. If the persist fails we REFUSE the load
+      // (re-throw) rather than hand out an unpersisted fresh-client-id rebuild —
+      // returning it would re-arm the duplication trap. A transient DB failure
+      // means the client reconnects and retries: correctness over availability.
+      try {
+        return await this.healUnderLock(pageId);
+      } catch (err) {
+        this.logger.error(
+          `Failed to persist rebuilt ydoc for page ${pageId}; refusing load`,
+          err,
+        );
+        throw err;
+      }
     }
 
     this.logger.debug(`creating fresh ydoc: ${pageId}`);
     return new Y.Doc();
   }
 
+  /**
+   * Serialize the legacy self-heal (rebuild from page.content and/or seed the
+   * title fragment, then persist) so it runs exactly ONCE per page, closing the
+   * Yjs duplication trap. Both TiptapTransformer.toYdoc and buildTitleSeedYdoc
+   * mint FRESH Yjs client-ids every call, so two concurrent rebuilds (the API
+   * process via openDirectConnection AND the standalone collab process both
+   * seeing `ydoc IS NULL`) could each persist a different-client-id state and let
+   * a long-offline client merge-and-duplicate. We prevent that by re-reading the
+   * row FOR UPDATE inside a transaction and re-validating state under the lock:
+   * whoever wins the lock heals; the loser observes the healthy `ydoc` and adopts
+   * it instead of rebuilding. The persist happens IN THE SAME TX, so a failed
+   * write rolls back and propagates out (the caller then decides refuse vs.
+   * fall-back).
+   */
+  private async healUnderLock(pageId: string): Promise<Y.Doc> {
+    return executeTx(this.db, async (trx) => {
+      const locked = await this.pageRepo.findById(pageId, {
+        withLock: true,
+        includeContent: true,
+        includeYdoc: true,
+        trx,
+      });
+
+      const doc = new Y.Doc();
+      let rebuilt = false;
+
+      if (locked?.ydoc) {
+        // Another process already healed (or the page always had a ydoc): adopt
+        // the healthy persisted state, do NOT rebuild.
+        Y.applyUpdate(doc, new Uint8Array(locked.ydoc));
+      } else if (locked?.content) {
+        this.logger.debug(`converting json to ydoc: ${pageId}`);
+        const built = TiptapTransformer.toYdoc(
+          locked.content,
+          'default',
+          tiptapExtensions,
+        );
+        Y.applyUpdate(doc, Y.encodeStateAsUpdate(built));
+        rebuilt = true;
+      }
+      // else: no ydoc and no content -> a fresh empty doc.
+
+      // Idempotent, emptiness-guarded title seed (safe to call always).
+      const seeded = this.seedTitleFragment(doc, locked?.title ?? null);
+
+      if (rebuilt || seeded) {
+        // Persist IN THE SAME TX. If this throws, the tx rolls back and the
+        // error propagates out of executeTx to the caller.
+        await this.pageRepo.updatePage(
+          { ydoc: Buffer.from(Y.encodeStateAsUpdate(doc)) },
+          pageId,
+          trx,
+        );
+        this.logger.debug(`persisted rebuilt/seeded ydoc: ${pageId}`);
+      }
+
+      return doc;
+    });
+  }
+
+  /**
+   * Seed the 'title' fragment of `doc` from the `page.title` column for legacy
+   * pages whose persisted ydoc has no title fragment yet.
+   *
+   * Guarded STRICTLY by emptiness: we only seed when the existing 'title'
+   * fragment is empty AND there is a non-empty column title. Seeding a non-empty
+   * fragment would re-introduce the Yjs duplication trap, so we never do it.
+   * Returns true when a seed was applied (so the caller can persist).
+   * Defensive: a malformed title must not break document loading.
+   */
+  private seedTitleFragment(doc: Y.Doc, title: string | null): boolean {
+    const trimmed = (title ?? '').trim();
+    if (!trimmed) return false;
+
+    try {
+      const titleFrag = doc.get('title', Y.XmlFragment);
+      if (titleFrag.length !== 0) return false;
+
+      const titleSeed = buildTitleSeedYdoc(title);
+      Y.applyUpdate(doc, Y.encodeStateAsUpdate(titleSeed));
+      this.logger.debug('seeded title fragment from page.title column');
+      return true;
+    } catch (err) {
+      this.logger.warn(`failed to seed title fragment: ${err?.['message']}`);
+      return false;
+    }
+  }
+
   async onStoreDocument(data: onStoreDocumentPayload) {
     const { documentName, document, context } = data;
 
@@ -171,7 +307,34 @@ export class PersistenceExtension implements Extension {
       this.logger.warn('jsonToText' + err?.['message']);
     }
 
+    // Title lives in the SAME Y.Doc as the body, in a dedicated 'title' fragment
+    // (the collaborative title-editor contract with the client). Extract it
+    // defensively: a malformed title fragment must NOT crash the document store.
+    // `hasTitleFragment` distinguishes "the doc actually carries a title
+    // fragment" from "legacy doc with no title fragment" — only the former may
+    // write page.title, so a legacy doc never clobbers the column with ''.
+    let titleText = '';
+    let hasTitleFragment = false;
+    try {
+      const titleFrag = document.get('title', Y.XmlFragment);
+      hasTitleFragment = !!titleFrag && titleFrag.length > 0;
+      if (hasTitleFragment) {
+        const titleJson = TiptapTransformer.fromYdoc(document, 'title');
+        titleText = titleJson ? jsonToText(titleJson).trim() : '';
+      }
+    } catch (err) {
+      this.logger.warn('title extraction: ' + err?.['message']);
+      hasTitleFragment = false;
+    }
+
     let page: Page = null;
+    // Tracks whether the BODY ('default') changed in this store. The heavy
+    // body-only side-effects (transclusion sync, mentions, RAG, history) stay
+    // gated on this so a title-only change does not trigger them.
+    let bodyChanged = false;
+    // Tracks a successful title-only persist so the post-tx contributor folding
+    // (collabHistory.addContributors) runs for the title-only case too.
+    let titleOnlyPersisted = false;
     const editingUserIds = this.consumeContributors(documentName);
     // Sticky agent marker: 'agent' if any agent edit landed in this window, OR
     // if the current writer is the agent (covers a store with no prior onChange
@@ -205,11 +368,80 @@ export class PersistenceExtension implements Extension {
             return;
           }
 
-          if (isDeepStrictEqual(tiptapJson, page.content)) {
+          bodyChanged = !isDeepStrictEqual(tiptapJson, page.content);
+          // Only a populated 'title' fragment may update page.title; compare
+          // against the current column value (treat null as '').
+          //
+          // ANTI-CORRUPTION GUARD (Bug 2): the client's collaborative title-editor
+          // can momentarily initialize the 'title' fragment as an EMPTY heading
+          // (so `hasTitleFragment` is true, but the extracted `titleText` is '')
+          // BEFORE the server's real-title seed has synced. Writing that '' would
+          // silently wipe a non-empty page.title to "untitled". A wiki page is
+          // never legitimately retitled to empty via this path, so we treat an
+          // empty extracted title as "not authoritative" and never persist it.
+          // The `titleText.length > 0` clause makes this guard apply to BOTH the
+          // title-only branch and the body+title branch below.
+          //
+          // DELIBERATE: this intentionally makes it impossible to retitle a page
+          // to EMPTY via the collab path — a wiki page is never legitimately
+          // empty-titled. If a non-empty-title rule ever needs relaxing or
+          // enforcing differently, the REST UpdatePageDto is the place to validate
+          // the title, not this collab guard.
+          const titleChanged =
+            hasTitleFragment &&
+            titleText.length > 0 &&
+            titleText !== (page.title ?? '');
+
+          // No-op fast path: neither body nor title changed.
+          if (!bodyChanged && !titleChanged) {
             page = null;
             return;
           }
 
+          // Title-only change: the body is unchanged, so skip the heavy body
+          // history/contributor logic and persist just the new title and the
+          // ydoc (the title fragment edit lives in the same ydoc). The early-skip
+          // used to drop this case entirely, losing the title change.
+          if (!bodyChanged) {
+            // Fold the window's editing users into contributors the same way the
+            // body branch does, so a user who edited ONLY the title is not dropped
+            // from page.contributorIds.
+            const contributorIds = Array.from(
+              new Set([
+                ...(page.contributorIds || []),
+                ...editingUserIds,
+                page.creatorId,
+              ]),
+            );
+            await this.pageRepo.updatePage(
+              {
+                title: titleText,
+                ydoc: ydocState,
+                lastUpdatedById: context.user.id,
+                contributorIds,
+                // A title-only change is not a body-authorship transition; leave
+                // lastUpdatedSource/aiChatId untouched so the user->agent history
+                // boundary in the body branch is not bypassed.
+              },
+              pageId,
+              trx,
+              // Mirror PageService.update's tree snapshot so a collaborative rename
+              // propagates to other users' sidebar/breadcrumbs like the REST rename.
+              {
+                treeUpdate: {
+                  id: pageId,
+                  slugId: page.slugId,
+                  spaceId: page.spaceId,
+                  parentPageId: page.parentPageId ?? null,
+                  title: titleText,
+                },
+              },
+            );
+            this.logger.debug(`Page title updated: ${pageId} - SlugId: ${page.slugId}`);
+            titleOnlyPersisted = true;
+            return;
+          }
+
           let contributorIds = undefined;
           try {
             const existingContributors = page.contributorIds || [];
@@ -227,29 +459,22 @@ export class PersistenceExtension implements Extension {
           // Approach A — boundary snapshot before the agent's first edit.
           // When this store is the agent's and the page's currently persisted
           // state was authored by a human, pin that human state as its own
-          // history version BEFORE the agent overwrites it. `page` still holds
-          // the OLD content/provenance here, so saveHistory(page) captures the
-          // pre-agent state tagged 'user'. The agent's new content is
-          // snapshotted later by the debounced PAGE_HISTORY job ('agent'). Skip
-          // if the prior state is already agent-authored (boundary already
-          // pinned on the user->agent transition), if the page is effectively
-          // empty, or if the latest existing snapshot already equals this human
-          // state (avoid duplicates).
-          if (
-            lastUpdatedSource === 'agent' &&
-            page.lastUpdatedSource !== 'agent'
-          ) {
+          // history version BEFORE the agent overwrites it. `page` still holds the
+          // OLD content/provenance here, so saveHistory(page) captures the
+          // pre-agent state tagged 'user'. The agent's new content is snapshotted
+          // later by the debounced PAGE_HISTORY job ('agent'). Skip if the prior
+          // state is already agent-authored (boundary already pinned on the
+          // user->agent transition), if the page is effectively empty, or if the
+          // latest existing snapshot already equals this human state (avoid
+          // duplicates).
+          if (lastUpdatedSource === 'agent' && page.lastUpdatedSource !== 'agent') {
             const lastHistory = await this.pageHistoryRepo.findPageLastHistory(
               pageId,
               { includeContent: true, trx },
             );
             const humanBaselineMissing =
-              !lastHistory ||
-              !isDeepStrictEqual(lastHistory.content, page.content);
-            if (
-              !isEmptyParagraphDoc(page.content as any) &&
-              humanBaselineMissing
-            ) {
+              !lastHistory || !isDeepStrictEqual(lastHistory.content, page.content);
+            if (!isEmptyParagraphDoc(page.content as any) && humanBaselineMissing) {
               await this.pageHistoryRepo.saveHistory(page, {
                 contributorIds: page.contributorIds ?? undefined,
                 trx,
@@ -267,9 +492,27 @@ export class PersistenceExtension implements Extension {
               lastUpdatedSource,
               lastUpdatedAiChatId: context?.aiChatId ?? null,
               contributorIds: contributorIds,
+              // Persist the title in the SAME transaction when the title fragment
+              // changed alongside the body.
+              ...(titleChanged ? { title: titleText } : {}),
             },
             pageId,
             trx,
+            // Mirror PageService.update's tree snapshot so a collaborative rename
+            // propagates to other users' sidebar/breadcrumbs like the REST rename.
+            // Only attach when the title actually changed; a body-only save must
+            // not trigger a tree broadcast.
+            titleChanged
+              ? {
+                  treeUpdate: {
+                    id: pageId,
+                    slugId: page.slugId,
+                    spaceId: page.spaceId,
+                    parentPageId: page.parentPageId ?? null,
+                    title: titleText,
+                  },
+                }
+              : undefined,
           );
 
           this.logger.debug(`Page updated: ${pageId} - SlugId: ${page.slugId}`);
@@ -290,6 +533,8 @@ export class PersistenceExtension implements Extension {
       }
     }
 
+    // `page` is truthy whenever anything was persisted (body OR title-only), so
+    // the page.updated broadcast fires for a title-only change too.
     if (page) {
       document.broadcastStateless(
         JSON.stringify({
@@ -307,11 +552,20 @@ export class PersistenceExtension implements Extension {
             : undefined,
         }),
       );
+    }
 
+    // Record the window's editing users in collab history for a title-only
+    // change too (the body branch does this below, gated on bodyChanged).
+    if (page && titleOnlyPersisted) {
+      await this.collabHistory.addContributors(pageId, editingUserIds);
+    }
+
+    // Body-only side-effects: skip them for a title-only change (body unchanged).
+    if (page && bodyChanged) {
       await this.syncTransclusion(pageId, page.workspaceId, tiptapJson);
     }
 
-    if (page) {
+    if (page && bodyChanged) {
       await this.collabHistory.addContributors(pageId, editingUserIds);
 
       const mentions = extractMentions(tiptapJson);

apps/server/src/collaboration/listeners/page-tree-bridge.publisher.spec.ts

@@ -0,0 +1,81 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import { PageTreeBridgePublisher } from './page-tree-bridge.publisher';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../constants';
+import {
+  PageEvent,
+  TreeUpdateSnapshot,
+} from '../../database/listeners/page.listener';
+
+const treeUpdate: TreeUpdateSnapshot = {
+  id: 'page-1',
+  slugId: 'slug-1',
+  spaceId: 'space-1',
+  parentPageId: null,
+  title: 'Renamed',
+  icon: '🚀',
+};
+
+describe('PageTreeBridgePublisher', () => {
+  let publisher: PageTreeBridgePublisher;
+  let redis: { publish: jest.Mock };
+
+  beforeEach(async () => {
+    redis = { publish: jest.fn().mockResolvedValue(1) };
+    const redisService = { getOrThrow: () => redis } as unknown as RedisService;
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        PageTreeBridgePublisher,
+        { provide: RedisService, useValue: redisService },
+      ],
+    }).compile();
+
+    publisher = module.get<PageTreeBridgePublisher>(PageTreeBridgePublisher);
+  });
+
+  it('WITH a `treeUpdate`: publishes the JSON snapshot on the channel', async () => {
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+      treeUpdate,
+    };
+
+    await publisher.onPageUpdated(event);
+
+    expect(redis.publish).toHaveBeenCalledTimes(1);
+    expect(redis.publish).toHaveBeenCalledWith(
+      COLLAB_TREE_UPDATE_CHANNEL,
+      JSON.stringify(treeUpdate),
+    );
+  });
+
+  it('content-only save (NO `treeUpdate`): does NOT publish', async () => {
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+    };
+
+    await publisher.onPageUpdated(event);
+
+    expect(redis.publish).not.toHaveBeenCalled();
+  });
+
+  it('a publish rejection is caught (no throw)', async () => {
+    redis.publish.mockRejectedValueOnce(new Error('redis down'));
+    const errorSpy = jest
+      .spyOn(publisher['logger'], 'error')
+      .mockImplementation(() => undefined);
+
+    const event: PageEvent = {
+      pageIds: ['page-1'],
+      workspaceId: 'ws-1',
+      treeUpdate,
+    };
+
+    await expect(publisher.onPageUpdated(event)).resolves.toBeUndefined();
+    expect(errorSpy).toHaveBeenCalledTimes(1);
+
+    errorSpy.mockRestore();
+  });
+});

apps/server/src/collaboration/listeners/page-tree-bridge.publisher.ts

@@ -0,0 +1,55 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import type { Redis } from 'ioredis';
+import { EventName } from '../../common/events/event.contants';
+import { PageEvent } from '../../database/listeners/page.listener';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../constants';
+
+/**
+ * Collab-process half of the cross-process tree-update bridge.
+ *
+ * The standalone collab process bootstraps `CollabAppModule`, which does NOT
+ * import `WsModule`/`PageWsListener`. So when a collaborative title/icon rename
+ * persists and emits `EventName.PAGE_UPDATED` with a `treeUpdate` snapshot, there
+ * is no listener in this process to broadcast it — the live tree update would be
+ * lost for 2-process (COLLAB_URL set) deployments.
+ *
+ * This publisher fills that gap: it forwards the `treeUpdate` snapshot over a
+ * Redis pub/sub channel to the API process, which re-broadcasts it via
+ * `WsTreeService` (the single broadcast authority).
+ *
+ * It is registered ONLY in `CollabAppModule.providers`, so it never runs in the
+ * API process (where `PageWsListener` already broadcasts the same event locally).
+ * That module placement is what prevents a double broadcast. In single-process
+ * mode `CollabAppModule` is not loaded at all, so this publisher never runs.
+ */
+@Injectable()
+export class PageTreeBridgePublisher {
+  private readonly logger = new Logger(PageTreeBridgePublisher.name);
+  private readonly redis: Redis;
+
+  constructor(private readonly redisService: RedisService) {
+    this.redis = this.redisService.getOrThrow();
+  }
+
+  @OnEvent(EventName.PAGE_UPDATED)
+  async onPageUpdated(event: PageEvent): Promise<void> {
+    // Mirror PageWsListener's gating: only title/icon changes carry a snapshot.
+    // Content-only saves leave `treeUpdate` undefined and are ignored.
+    if (!event.treeUpdate) return;
+
+    try {
+      await this.redis.publish(
+        COLLAB_TREE_UPDATE_CHANNEL,
+        JSON.stringify(event.treeUpdate),
+      );
+    } catch (err) {
+      // A Redis publish failure must not break the store path.
+      this.logger.error(
+        `Failed to publish tree update to ${COLLAB_TREE_UPDATE_CHANNEL}`,
+        err instanceof Error ? err.stack : String(err),
+      );
+    }
+  }
+}

apps/server/src/collaboration/server/collab-app.module.ts

@@ -20,6 +20,7 @@ import { CaslModule } from '../../core/casl/casl.module';
 import { ThrottleModule } from '../../integrations/throttle/throttle.module';
 import { CacheModule } from '@nestjs/cache-manager';
 import KeyvRedis from '@keyv/redis';
+import { PageTreeBridgePublisher } from '../listeners/page-tree-bridge.publisher';
 
 @Module({
   imports: [
@@ -54,6 +55,6 @@ import KeyvRedis from '@keyv/redis';
       ? [CollaborationController]
       : []),
   ],
-  providers: [AppService],
+  providers: [AppService, PageTreeBridgePublisher],
 })
 export class CollabAppModule {}

apps/server/src/core/auth/auth.controller.spec.ts

@@ -19,4 +19,87 @@ describe('AuthController', () => {
   it('should be defined', () => {
     expect(controller).toBeDefined();
   });
+
+  // The EE MFA module is absent in this repo, so require() throws and is caught;
+  // login falls through to authService.login -> setAuthCookie -> returnToken.
+  describe('login returnToken branch', () => {
+    const workspace = { id: 'ws1', enforceSso: false };
+
+    const makeController = () => {
+      const authService = {
+        login: jest.fn().mockResolvedValue('jwt-token-123'),
+      };
+      const environmentService = {
+        getCookieExpiresIn: jest.fn().mockReturnValue(new Date()),
+        isHttps: jest.fn().mockReturnValue(false),
+      };
+      const ctrl = new AuthController(
+        authService as any,
+        {} as any,
+        environmentService as any,
+        {} as any,
+        {} as any,
+      );
+      const res = { setCookie: jest.fn() };
+      return { ctrl, authService, res };
+    };
+
+    it('returns the body token and sets the cookie when returnToken is true', async () => {
+      const { ctrl, authService, res } = makeController();
+      const loginInput = {
+        email: 'a@b.com',
+        password: 'pw',
+        returnToken: true,
+      };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toEqual({ authToken: 'jwt-token-123' });
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+      expect(res.setCookie).toHaveBeenCalledWith(
+        'authToken',
+        'jwt-token-123',
+        expect.objectContaining({ httpOnly: true }),
+      );
+      expect(authService.login).toHaveBeenCalled();
+    });
+
+    it('returns no body token but still sets the cookie when returnToken is omitted', async () => {
+      const { ctrl, res } = makeController();
+      const loginInput = { email: 'a@b.com', password: 'pw' };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toBeUndefined();
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+    });
+
+    // Guards against an `!== undefined`-style bug: an explicit `false` must
+    // behave exactly like the omitted case (cookie set, no token in the body).
+    it('returns no body token but still sets the cookie when returnToken is false', async () => {
+      const { ctrl, res } = makeController();
+      const loginInput = {
+        email: 'a@b.com',
+        password: 'pw',
+        returnToken: false,
+      };
+
+      const result = await ctrl.login(
+        workspace as any,
+        res as any,
+        loginInput as any,
+      );
+
+      expect(result).toBeUndefined();
+      expect(res.setCookie).toHaveBeenCalledTimes(1);
+    });
+  });
 });

apps/server/src/core/auth/auth.controller.ts

@@ -97,6 +97,12 @@ export class AuthController {
         } else if (mfaResult.authToken) {
           // User doesn't have MFA and workspace doesn't require it
           this.setAuthCookie(res, mfaResult.authToken);
+          // Opt-in body token for native clients (Bearer auth). The response is
+          // wrapped by TransformHttpResponseInterceptor, so clients read it at
+          // `data.authToken`. Web clients omit returnToken and keep the cookie.
+          if (loginInput.returnToken) {
+            return { authToken: mfaResult.authToken };
+          }
           return;
         }
       }
@@ -104,6 +110,12 @@ export class AuthController {
 
     const authToken = await this.authService.login(loginInput, workspace.id);
     this.setAuthCookie(res, authToken);
+    // Opt-in body token for native clients (Bearer auth). The response is wrapped
+    // by TransformHttpResponseInterceptor, so clients read it at `data.authToken`.
+    // Web clients omit returnToken and keep using the httpOnly cookie only.
+    if (loginInput.returnToken) {
+      return { authToken };
+    }
   }
 
   @UseGuards(SetupGuard)

apps/server/src/core/auth/dto/login.dto.ts

@@ -1,4 +1,10 @@
-import { IsEmail, IsNotEmpty, IsString } from 'class-validator';
+import {
+  IsBoolean,
+  IsEmail,
+  IsNotEmpty,
+  IsOptional,
+  IsString,
+} from 'class-validator';
 
 export class LoginDto {
   @IsNotEmpty()
@@ -8,4 +14,13 @@ export class LoginDto {
   @IsNotEmpty()
   @IsString()
   password: string;
+
+  // When true, the access token is returned in the response body (in addition
+  // to the httpOnly cookie) so native/mobile clients can store it in
+  // Keychain/Keystore and send it as 'Authorization: Bearer'. Web clients omit
+  // this flag and keep using the cookie. Opt-in only: the token is never put in
+  // the body otherwise.
+  @IsOptional()
+  @IsBoolean()
+  returnToken?: boolean;
 }

apps/server/src/core/page/services/page.service.spec.ts

@@ -31,6 +31,102 @@ describe('PageService', () => {
     expect(service).toBeDefined();
   });
 
+  describe('update — title sync into collab doc (Bug 1)', () => {
+    const makeUpdateService = () => {
+      const pageRepo = {
+        updatePage: jest.fn().mockResolvedValue(undefined),
+        findById: jest.fn().mockResolvedValue({ id: 'page-1' }),
+      };
+      const generalQueue = { add: jest.fn().mockResolvedValue(undefined) };
+      const collaborationGateway = {
+        writePageTitle: jest.fn().mockResolvedValue(undefined),
+      };
+
+      const svc = new PageService(
+        pageRepo as any, // pageRepo
+        {} as any, // pagePermissionRepo
+        {} as any, // attachmentRepo
+        {} as any, // db
+        {} as any, // storageService
+        {} as any, // attachmentQueue
+        {} as any, // aiQueue
+        generalQueue as any, // generalQueue
+        {} as any, // eventEmitter
+        collaborationGateway as any, // collaborationGateway
+        {} as any, // watcherService
+        {} as any, // transclusionService
+      );
+
+      return { svc, pageRepo, collaborationGateway };
+    };
+
+    const basePage = (): Page =>
+      ({
+        id: 'page-1',
+        slugId: 'slug-1',
+        spaceId: 'space-1',
+        workspaceId: 'ws-1',
+        parentPageId: null,
+        title: 'Old Title',
+        icon: null,
+        contributorIds: [],
+      }) as any;
+
+    const user = { id: 'u1' } as any;
+
+    it('writes the new title into the collab doc when the title actually changed', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { title: 'New Title' } as any, user);
+
+      // Must use the Redis-independent writePageTitle (direct
+      // openDirectConnection), NOT handleYjsEvent which no-ops without Redis.
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledTimes(1);
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledWith(
+        'page-1',
+        'New Title',
+        expect.objectContaining({ user }),
+      );
+    });
+
+    it('threads agent provenance into the collab title write', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { title: 'New Title' } as any, user, {
+        actor: 'agent',
+        aiChatId: 'chat-1',
+      } as any);
+
+      expect(collaborationGateway.writePageTitle).toHaveBeenCalledWith(
+        'page-1',
+        'New Title',
+        expect.objectContaining({ actor: 'agent', aiChatId: 'chat-1' }),
+      );
+    });
+
+    it('does NOT write into the collab doc when the title is unchanged', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      // Same title -> titleChanged is false; an icon-only change must not fire
+      // the title sync.
+      await svc.update(
+        basePage(),
+        { title: 'Old Title', icon: '📄' } as any,
+        user,
+      );
+
+      expect(collaborationGateway.writePageTitle).not.toHaveBeenCalled();
+    });
+
+    it('does NOT write into the collab doc when the DTO omits the title', async () => {
+      const { svc, collaborationGateway } = makeUpdateService();
+
+      await svc.update(basePage(), { icon: '📄' } as any, user);
+
+      expect(collaborationGateway.writePageTitle).not.toHaveBeenCalled();
+    });
+  });
+
   describe('movePage cycle guard (#67)', () => {
     // A valid fractional-indexing key — movePage validates `position` by feeding
     // it to generateJitteredKeyBetween(position, null) before anything else.

apps/server/src/core/page/services/page.service.ts

@@ -265,6 +265,8 @@ export class PageService {
     contributors.add(user.id);
     const contributorIds = Array.from(contributors);
 
+    const isAgent = provenance?.actor === 'agent';
+
     // Detect a real title/icon change so the WS tree listener can broadcast an
     // `updateOne` to the space (rename / icon swap) WITHOUT re-broadcasting on a
     // content-only save. Only treat a field as changed when the DTO actually
@@ -307,6 +309,43 @@ export class PageService {
         : undefined,
     );
 
+    // Bug 1: a REST/MCP rename wrote the new title ONLY to the page.title DB
+    // column above. The title's source of truth is the Yjs 'title' fragment in
+    // the page's collab doc, which onStoreDocument re-extracts on every save —
+    // so leaving the fragment stale would REVERT this rename on the page's next
+    // collaborative save (and re-broadcast the old title). Push the new title
+    // into the Yjs 'title' fragment so Yjs stays in sync and never reverts.
+    //
+    // Use the gateway's writePageTitle (direct openDirectConnection) rather than
+    // a Redis-routed handleYjsEvent path: handleYjsEvent routes through
+    // redisSync and SILENTLY no-ops when Redis is disabled
+    // (COLLAB_DISABLE_REDIS=true), which would let the rename revert in a
+    // single-process deployment. writePageTitle is Redis-independent and
+    // openDirectConnection loads the doc from persistence when no editor is
+    // connected, so this also works for an offline page. Thread agent provenance
+    // into the context so onStoreDocument tags the title store 'agent' too.
+    if (titleChanged) {
+      try {
+        await this.collaborationGateway.writePageTitle(
+          page.id,
+          updatePageDto.title,
+          {
+            user,
+            ...(isAgent
+              ? { actor: 'agent', aiChatId: provenance.aiChatId }
+              : {}),
+          },
+        );
+      } catch (err) {
+        // The DB column write already succeeded (fast-read source stays
+        // correct); a failure to sync Yjs here must not fail the rename. Log so
+        // a persistent desync is visible.
+        this.logger.warn(
+          `Failed to sync renamed title into collab doc for page ${page.id}: ${err?.['message']}`,
+        );
+      }
+    }
+
     this.generalQueue
       .add(QueueJob.ADD_PAGE_WATCHERS, {
         userIds: [user.id],

apps/server/src/integrations/environment/cors.util.spec.ts

@@ -0,0 +1,93 @@
+import { buildCorsAllowlist, isOriginAllowed } from './cors.util';
+
+const WEBVIEW_ORIGINS = [
+  'capacitor://localhost',
+  'ionic://localhost',
+  'https://localhost',
+];
+
+describe('isOriginAllowed', () => {
+  const allowlist = buildCorsAllowlist({
+    appUrl: 'https://app.example',
+    configuredOrigins: ['https://other.example'],
+  });
+
+  it('allows requests with no Origin header', () => {
+    expect(isOriginAllowed(undefined, allowlist)).toBe(true);
+    expect(isOriginAllowed('', allowlist)).toBe(true);
+  });
+
+  it('allows an exact allowlisted origin', () => {
+    expect(isOriginAllowed('https://app.example', allowlist)).toBe(true);
+    expect(isOriginAllowed('https://other.example', allowlist)).toBe(true);
+  });
+
+  it('allows each native WebView origin', () => {
+    for (const origin of WEBVIEW_ORIGINS) {
+      expect(isOriginAllowed(origin, allowlist)).toBe(true);
+    }
+  });
+
+  it('rejects a foreign credentialed origin', () => {
+    // With credentials:true a foreign credentialed origin must be rejected.
+    expect(isOriginAllowed('https://evil.example', allowlist)).toBe(false);
+  });
+
+  it('rejects the cleartext http://localhost origin', () => {
+    // The native shell uses the secure scheme (https://localhost) on Android and
+    // the capacitor:// custom scheme on iOS, so cleartext http://localhost must
+    // not be trusted.
+    expect(isOriginAllowed('http://localhost', allowlist)).toBe(false);
+  });
+
+  it('rejects a trailing-slash mismatch', () => {
+    expect(isOriginAllowed('https://app.example/', allowlist)).toBe(false);
+  });
+
+  it('rejects a host-case mismatch', () => {
+    expect(isOriginAllowed('https://APP.example', allowlist)).toBe(false);
+  });
+
+  it('allows no-Origin but rejects cross-origin with an empty allowlist', () => {
+    const empty: ReadonlySet<string> = new Set<string>();
+    expect(isOriginAllowed(undefined, empty)).toBe(true);
+    expect(isOriginAllowed('https://app.example', empty)).toBe(false);
+  });
+});
+
+describe('buildCorsAllowlist', () => {
+  it('contains the app URL, each configured origin, and all WebView origins', () => {
+    const allowlist = buildCorsAllowlist({
+      appUrl: 'https://app.example',
+      configuredOrigins: ['https://a.example', 'https://b.example'],
+    });
+
+    expect(allowlist.has('https://app.example')).toBe(true);
+    expect(allowlist.has('https://a.example')).toBe(true);
+    expect(allowlist.has('https://b.example')).toBe(true);
+    for (const origin of WEBVIEW_ORIGINS) {
+      expect(allowlist.has(origin)).toBe(true);
+    }
+  });
+
+  it('deduplicates when a configured origin coincides with the app URL', () => {
+    const allowlist = buildCorsAllowlist({
+      appUrl: 'https://app.example',
+      configuredOrigins: ['https://app.example'],
+    });
+
+    // app URL + WebView origins, the duplicate configured origin collapses.
+    expect(allowlist.size).toBe(1 + WEBVIEW_ORIGINS.length);
+  });
+
+  it('always includes every WebView origin even with no configured origins', () => {
+    const allowlist = buildCorsAllowlist({
+      appUrl: 'https://app.example',
+      configuredOrigins: [],
+    });
+
+    for (const origin of WEBVIEW_ORIGINS) {
+      expect(allowlist.has(origin)).toBe(true);
+    }
+  });
+});

apps/server/src/integrations/environment/cors.util.ts

@@ -0,0 +1,50 @@
+// CORS trust boundary helpers. `buildCorsAllowlist` produces the exact set of
+// origins the API trusts, and `isOriginAllowed` is the predicate the enableCors
+// origin callback uses to accept/reject each request. With credentials:true a
+// foreign credentialed origin must never be allowed, so anything not in the
+// allowlist (apart from no-Origin requests) is rejected.
+
+// Native WebView origins used by the Capacitor/Ionic mobile shell. Always
+// trusted so the native client can call the API.
+//
+//   - `capacitor://localhost` — iOS native custom scheme.
+//   - `ionic://localhost`     — legacy native custom scheme.
+//   - `https://localhost`     — Android default secure scheme.
+//
+// The cleartext `http://localhost` origin is intentionally NOT trusted: the
+// Capacitor shell uses the secure scheme (capacitor.config.ts sets
+// `cleartext: false` and does not override `androidScheme`, so Capacitor's
+// default Android scheme is `https` => origin `https://localhost`), and iOS runs
+// in hosted mode (`server.url` = CAP_SERVER_URL, whose origin is the app URL
+// already in the allowlist). No native client legitimately uses
+// `http://localhost`, so allowing it would only widen the credentialed-CORS
+// surface to arbitrary local http content.
+const NATIVE_WEBVIEW_ORIGINS = [
+  'capacitor://localhost',
+  'ionic://localhost',
+  'https://localhost',
+] as const;
+
+// Build the CORS allowlist: the app URL, all configured cross-origin clients,
+// and the native WebView origins. Dedup is automatic via Set.
+export function buildCorsAllowlist(input: {
+  appUrl: string;
+  configuredOrigins: readonly string[];
+}): Set<string> {
+  return new Set<string>([
+    input.appUrl,
+    ...input.configuredOrigins,
+    ...NATIVE_WEBVIEW_ORIGINS,
+  ]);
+}
+
+// Decide whether a request's Origin is allowed. A missing Origin header (curl,
+// server-to-server, some native WebViews) is allowed; otherwise the origin must
+// be present in the allowlist.
+export function isOriginAllowed(
+  origin: string | undefined,
+  allowlist: ReadonlySet<string>,
+): boolean {
+  if (!origin) return true;
+  return allowlist.has(origin);
+}

apps/server/src/integrations/environment/environment.service.spec.ts

@@ -5,6 +5,13 @@ import { EnvironmentService } from './environment.service';
 describe('EnvironmentService', () => {
   let service: EnvironmentService;
 
+  // Build a service over a stub ConfigService whose get(key, def) returns
+  // values from the supplied env map (falling back to the provided default).
+  const makeService = (env: Record<string, string>) =>
+    new EnvironmentService({
+      get: (k: string, d?: string) => (k in env ? env[k] : d),
+    } as any);
+
   beforeEach(() => {
     service = new EnvironmentService(
       {} as any, // configService
@@ -14,4 +21,72 @@ describe('EnvironmentService', () => {
   it('should be defined', () => {
     expect(service).toBeDefined();
   });
+
+  describe('getCorsAllowedOrigins', () => {
+    it('splits, trims, and drops empty entries', () => {
+      const svc = makeService({
+        CORS_ALLOWED_ORIGINS: 'https://a.com, https://b.com ,, https://c.com',
+      });
+      expect(svc.getCorsAllowedOrigins()).toEqual([
+        'https://a.com',
+        'https://b.com',
+        'https://c.com',
+      ]);
+    });
+
+    it('returns an empty array when the var is absent', () => {
+      const svc = makeService({});
+      expect(svc.getCorsAllowedOrigins()).toEqual([]);
+    });
+
+    it('returns an empty array for an empty string', () => {
+      const svc = makeService({ CORS_ALLOWED_ORIGINS: '' });
+      expect(svc.getCorsAllowedOrigins()).toEqual([]);
+    });
+
+    it('returns a single origin unchanged', () => {
+      const svc = makeService({
+        CORS_ALLOWED_ORIGINS: 'https://app.example',
+      });
+      expect(svc.getCorsAllowedOrigins()).toEqual(['https://app.example']);
+    });
+
+    // Adversarial case: leading/trailing/duplicate commas with surrounding
+    // spaces must be dropped, exercising both .map(trim) and .filter(Boolean).
+    it('drops leading/trailing commas with surrounding spaces', () => {
+      const svc = makeService({ CORS_ALLOWED_ORIGINS: ' , a , , b ' });
+      expect(svc.getCorsAllowedOrigins()).toEqual(['a', 'b']);
+    });
+  });
+
+  describe('isSwaggerEnabled', () => {
+    // Case-insensitive: "true" in any casing enables Swagger.
+    it.each(['true', 'TRUE', 'True'])('is true for "%s"', (value) => {
+      expect(
+        makeService({ SWAGGER_ENABLED: value }).isSwaggerEnabled(),
+      ).toBe(true);
+    });
+
+    it('defaults to false when absent', () => {
+      expect(makeService({}).isSwaggerEnabled()).toBe(false);
+    });
+
+    it('is false for non-"true" values', () => {
+      expect(makeService({ SWAGGER_ENABLED: '0' }).isSwaggerEnabled()).toBe(
+        false,
+      );
+      expect(makeService({ SWAGGER_ENABLED: 'yes' }).isSwaggerEnabled()).toBe(
+        false,
+      );
+      expect(makeService({ SWAGGER_ENABLED: 'false' }).isSwaggerEnabled()).toBe(
+        false,
+      );
+      expect(makeService({ SWAGGER_ENABLED: '' }).isSwaggerEnabled()).toBe(
+        false,
+      );
+      expect(makeService({ SWAGGER_ENABLED: '1' }).isSwaggerEnabled()).toBe(
+        false,
+      );
+    });
+  });
 });

apps/server/src/integrations/environment/environment.service.ts

@@ -332,4 +332,19 @@ export class EnvironmentService {
       .map((o) => o.trim())
       .filter(Boolean);
   }
+
+  getCorsAllowedOrigins(): string[] {
+    const raw = this.configService.get<string>('CORS_ALLOWED_ORIGINS', '');
+    return raw
+      .split(',')
+      .map((o) => o.trim())
+      .filter(Boolean);
+  }
+
+  isSwaggerEnabled(): boolean {
+    const enabled = this.configService
+      .get<string>('SWAGGER_ENABLED', 'false')
+      .toLowerCase();
+    return enabled === 'true';
+  }
 }

apps/server/src/main.ts

@@ -15,6 +15,11 @@ import { InternalLogFilter } from './common/logger/internal-log-filter';
 import { EnvironmentService } from './integrations/environment/environment.service';
 import { resolveFrameHeader } from './common/helpers';
 import { resolveTrustProxy } from './integrations/environment/trust-proxy.util';
+import {
+  buildCorsAllowlist,
+  isOriginAllowed,
+} from './integrations/environment/cors.util';
+import { DocumentBuilder, SwaggerModule } from '@nestjs/swagger';
 
 async function bootstrap() {
   const app = await NestFactory.create<NestFastifyApplication>(
@@ -149,8 +154,43 @@ async function bootstrap() {
     }),
   );
 
-  app.enableCors();
+  // Configure CORS explicitly (replaces the previous unconfigured enableCors()).
+  // The web client is same-origin in production; an explicit allowlist lets
+  // native/mobile WebView origins (Capacitor) and any configured cross-origin
+  // clients call the API, while everything else is rejected.
+  const corsAllowedOrigins = buildCorsAllowlist({
+    appUrl: environmentService.getAppUrl(),
+    configuredOrigins: environmentService.getCorsAllowedOrigins(),
+  });
+
+  app.enableCors({
+    // Allow requests with no Origin header (curl, server-to-server, some native
+    // WebView requests) and any origin in the allowlist; reject the rest.
+    origin: (
+      origin: string | undefined,
+      callback: (err: Error | null, allow?: boolean) => void,
+    ) => {
+      callback(null, isOriginAllowed(origin, corsAllowedOrigins));
+    },
+    credentials: true,
+    methods: ['GET', 'HEAD', 'PUT', 'PATCH', 'POST', 'DELETE', 'OPTIONS'],
+    allowedHeaders: ['Content-Type', 'Authorization'],
+  });
+
   app.useGlobalInterceptors(new TransformHttpResponseInterceptor(reflector));
+
+  if (environmentService.isSwaggerEnabled()) {
+    // Optional OpenAPI docs to speed up typed mobile-client generation.
+    const swaggerConfig = new DocumentBuilder()
+      .setTitle('Gitmost API')
+      .setDescription('Gitmost REST API (RPC-style POST endpoints).')
+      .setVersion(process.env.APP_VERSION || '0.0.0')
+      .addBearerAuth()
+      .build();
+    const document = SwaggerModule.createDocument(app, swaggerConfig);
+    SwaggerModule.setup('api/docs', app, document);
+  }
+
   app.enableShutdownHooks();
 
   const logger = new Logger('NestApplication');

apps/server/src/ws/listeners/page-tree-bridge.subscriber.spec.ts

@@ -0,0 +1,114 @@
+import { Test, TestingModule } from '@nestjs/testing';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import { PageTreeBridgeSubscriber } from './page-tree-bridge.subscriber';
+import { WsTreeService } from '../ws-tree.service';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../../collaboration/constants';
+import { TreeUpdateSnapshot } from '../../database/listeners/page.listener';
+
+const treeUpdate: TreeUpdateSnapshot = {
+  id: 'page-1',
+  slugId: 'slug-1',
+  spaceId: 'space-1',
+  parentPageId: null,
+  title: 'Renamed',
+  icon: '🚀',
+};
+
+describe('PageTreeBridgeSubscriber.onMessage', () => {
+  let subscriber: PageTreeBridgeSubscriber;
+  let wsTree: { broadcastPageUpdated: jest.Mock };
+
+  beforeEach(async () => {
+    wsTree = {
+      broadcastPageUpdated: jest.fn().mockResolvedValue(undefined),
+    };
+    // onMessage is driven directly; no real redis connection is needed.
+    const redisService = {
+      getOrThrow: () => ({ duplicate: () => ({}) }),
+    } as unknown as RedisService;
+
+    const module: TestingModule = await Test.createTestingModule({
+      providers: [
+        PageTreeBridgeSubscriber,
+        { provide: RedisService, useValue: redisService },
+        { provide: WsTreeService, useValue: wsTree },
+      ],
+    }).compile();
+
+    subscriber = module.get<PageTreeBridgeSubscriber>(PageTreeBridgeSubscriber);
+  });
+
+  it('valid JSON on the channel: broadcasts the parsed snapshot', async () => {
+    await subscriber.onMessage(
+      COLLAB_TREE_UPDATE_CHANNEL,
+      JSON.stringify(treeUpdate),
+    );
+
+    expect(wsTree.broadcastPageUpdated).toHaveBeenCalledTimes(1);
+    expect(wsTree.broadcastPageUpdated).toHaveBeenCalledWith(treeUpdate);
+  });
+
+  it('malformed JSON: does NOT broadcast and does not throw', async () => {
+    const warnSpy = jest
+      .spyOn(subscriber['logger'], 'warn')
+      .mockImplementation(() => undefined);
+
+    await expect(
+      subscriber.onMessage(COLLAB_TREE_UPDATE_CHANNEL, '{not json'),
+    ).resolves.toBeUndefined();
+
+    expect(wsTree.broadcastPageUpdated).not.toHaveBeenCalled();
+    expect(warnSpy).toHaveBeenCalledTimes(1);
+
+    warnSpy.mockRestore();
+  });
+
+  it('message on a different channel: ignored', async () => {
+    await subscriber.onMessage('some:other:channel', JSON.stringify(treeUpdate));
+
+    expect(wsTree.broadcastPageUpdated).not.toHaveBeenCalled();
+  });
+
+  it('broadcast rejects: onMessage does not throw / produce unhandled rejection', async () => {
+    wsTree.broadcastPageUpdated.mockRejectedValueOnce(new Error('db down'));
+    const warnSpy = jest
+      .spyOn(subscriber['logger'], 'warn')
+      .mockImplementation(() => undefined);
+
+    await expect(
+      subscriber.onMessage(
+        COLLAB_TREE_UPDATE_CHANNEL,
+        JSON.stringify(treeUpdate),
+      ),
+    ).resolves.toBeUndefined();
+
+    expect(wsTree.broadcastPageUpdated).toHaveBeenCalledTimes(1);
+    expect(warnSpy).toHaveBeenCalledTimes(1);
+
+    warnSpy.mockRestore();
+  });
+
+  it('onModuleInit when subscribe() rejects: resolves without throwing', async () => {
+    const sub = {
+      on: jest.fn(),
+      subscribe: jest.fn().mockRejectedValue(new Error('redis down')),
+    };
+    const redisService = {
+      getOrThrow: () => ({ duplicate: () => sub }),
+    } as unknown as RedisService;
+    const local = new PageTreeBridgeSubscriber(
+      redisService,
+      wsTree as unknown as WsTreeService,
+    );
+    const errorSpy = jest
+      .spyOn(local['logger'], 'error')
+      .mockImplementation(() => undefined);
+
+    await expect(local.onModuleInit()).resolves.toBeUndefined();
+
+    expect(sub.subscribe).toHaveBeenCalledTimes(1);
+    expect(errorSpy).toHaveBeenCalledTimes(1);
+
+    errorSpy.mockRestore();
+  });
+});

apps/server/src/ws/listeners/page-tree-bridge.subscriber.ts

@@ -0,0 +1,115 @@
+import {
+  Injectable,
+  Logger,
+  OnModuleDestroy,
+  OnModuleInit,
+} from '@nestjs/common';
+import { RedisService } from '@nestjs-labs/nestjs-ioredis';
+import type { Redis } from 'ioredis';
+import { COLLAB_TREE_UPDATE_CHANNEL } from '../../collaboration/constants';
+import { TreeUpdateSnapshot } from '../../database/listeners/page.listener';
+import { WsTreeService } from '../ws-tree.service';
+
+/**
+ * API-process half of the cross-process tree-update bridge.
+ *
+ * It subscribes to the Redis pub/sub channel that the collab process's
+ * `PageTreeBridgePublisher` publishes to and re-broadcasts each collab-originated
+ * `treeUpdate` snapshot through `WsTreeService`. This is what makes a
+ * collaborative rename reach other users' sidebars in 2-process (COLLAB_URL set)
+ * deployments. The API process is the single broadcast authority:
+ * `broadcastPageUpdated` routes through the restriction-aware `emitTreeEvent`, so
+ * this path stays authorization-safe.
+ *
+ * In single-process mode this subscriber still subscribes, but nobody publishes
+ * (the publisher lives only in `CollabAppModule`), so it stays idle and harmless.
+ *
+ * NOTE: this assumes a SINGLE API broadcaster. With multiple horizontally-scaled
+ * API replicas, every replica would receive the pub/sub message and re-broadcast,
+ * duplicating the client update (the Socket.IO Redis adapter already fans a single
+ * emit out to all replicas' clients). Scaling the API horizontally would require a
+ * consumer-group / leader-election scheme instead of fan-out pub/sub. That is out
+ * of scope for the current single-API deployment.
+ */
+@Injectable()
+export class PageTreeBridgeSubscriber
+  implements OnModuleInit, OnModuleDestroy
+{
+  private readonly logger = new Logger(PageTreeBridgeSubscriber.name);
+  private sub?: Redis;
+
+  constructor(
+    private readonly redisService: RedisService,
+    private readonly wsTree: WsTreeService,
+  ) {}
+
+  async onModuleInit(): Promise<void> {
+    // A connection in subscribe mode cannot run other commands, so use a
+    // dedicated duplicated client (mirrors RedisSyncExtension's `sub`).
+    this.sub = this.redisService.getOrThrow().duplicate();
+    // ioredis connections emit 'error' on disconnect/reconnect; an EventEmitter
+    // 'error' with no listener THROWS and can crash the process. The bridge is
+    // optional, so just log and stay alive (mirrors RedisSyncExtension).
+    this.sub.on('error', (err) =>
+      this.logger.warn(`tree-update subscriber redis error: ${err?.message}`),
+    );
+    this.sub.on('message', (channel, message) =>
+      this.onMessage(channel, message),
+    );
+    // The bridge is optional for core API operation: if Redis is down at boot,
+    // subscribe() rejects — log and continue rather than crash API bootstrap.
+    try {
+      await this.sub.subscribe(COLLAB_TREE_UPDATE_CHANNEL);
+    } catch (err) {
+      this.logger.error(
+        `Failed to subscribe to ${COLLAB_TREE_UPDATE_CHANNEL}; cross-process tree updates disabled: ${
+          err instanceof Error ? err.message : String(err)
+        }`,
+      );
+    }
+  }
+
+  async onMessage(channel: string, message: string): Promise<void> {
+    if (channel !== COLLAB_TREE_UPDATE_CHANNEL) return;
+
+    let snapshot: TreeUpdateSnapshot;
+    try {
+      snapshot = JSON.parse(message) as TreeUpdateSnapshot;
+    } catch (err) {
+      // Malformed payload must never throw out of the message handler.
+      this.logger.warn(
+        `Dropping malformed tree update on ${COLLAB_TREE_UPDATE_CHANNEL}: ${
+          err instanceof Error ? err.message : String(err)
+        }`,
+      );
+      return;
+    }
+
+    // broadcastPageUpdated -> emitTreeEvent does a DB permission read that can
+    // reject. ioredis does not await this handler, so a rejection would become
+    // an unhandled promise rejection — swallow it (warn, never rethrow).
+    try {
+      await this.wsTree.broadcastPageUpdated(snapshot);
+    } catch (err) {
+      this.logger.warn(
+        `Failed to broadcast tree update for page ${snapshot.id}: ${
+          err instanceof Error ? err.message : String(err)
+        }`,
+      );
+    }
+  }
+
+  async onModuleDestroy(): Promise<void> {
+    if (!this.sub) return;
+    try {
+      await this.sub.unsubscribe(COLLAB_TREE_UPDATE_CHANNEL);
+      await this.sub.quit();
+    } catch (err) {
+      this.logger.warn(
+        `Failed to tear down tree-update subscriber: ${
+          err instanceof Error ? err.message : String(err)
+        }`,
+      );
+    }
+  }
+}

apps/server/src/ws/ws.module.ts

@@ -3,12 +3,19 @@ import { WsGateway } from './ws.gateway';
 import { WsService } from './ws.service';
 import { WsTreeService } from './ws-tree.service';
 import { PageWsListener } from './listeners/page-ws.listener';
+import { PageTreeBridgeSubscriber } from './listeners/page-tree-bridge.subscriber';
 import { TokenModule } from '../core/auth/token.module';
 
 @Global()
 @Module({
   imports: [TokenModule],
-  providers: [WsGateway, WsService, WsTreeService, PageWsListener],
+  providers: [
+    WsGateway,
+    WsService,
+    WsTreeService,
+    PageWsListener,
+    PageTreeBridgeSubscriber,
+  ],
   exports: [WsGateway, WsService, WsTreeService],
 })
 export class WsModule {}

capacitor.config.ts

@@ -0,0 +1,29 @@
+import type { CapacitorConfig } from "@capacitor/cli";
+
+// Capacitor configuration for the Gitmost mobile shell.
+//
+// AGPL / App Store note (see docs/mobile-app-plan.md section 9): the AGPL web
+// client must NOT be bundled into the iOS .ipa. On iOS, point the shell at a
+// hosted client via CAP_SERVER_URL (server.url) so the AGPL bytes are served
+// from our own server rather than redistributed under Apple's DRM/usage-rules.
+// Android may bundle the local web build (webDir) directly.
+const serverUrl = process.env.CAP_SERVER_URL?.trim();
+
+const config: CapacitorConfig = {
+  appId: "xyz.vvzvlad.gitmost",
+  appName: "Gitmost",
+  // Web build output of apps/client (Android bundled mode / local assets).
+  // Build it with `pnpm run client:build` before `cap sync`.
+  webDir: "apps/client/dist",
+  ...(serverUrl
+    ? {
+        // iOS / hosted mode: load the client from our server (AGPL-clean).
+        server: {
+          url: serverUrl,
+          cleartext: false,
+        },
+      }
+    : {}),
+};
+
+export default config;

docs/mobile-app-plan.md

@@ -0,0 +1,367 @@
+# Мобильное приложение gitmost — исследование и план
+
+> Статус: исследовательский + проектный документ.
+> Контекст: gitmost — форк Docmost, чистое веб-приложение. Отдельного
+> мобильного (нативного/устанавливаемого) приложения **нет**.
+> Цель: определить путь к мобильным приложениям — **iOS обязательно, Android
+> как пойдёт** — с заделом на оффлайн в будущем (оффлайн сейчас не требуется).
+
+Документ фиксирует, что уже есть в коде, почему путь к мобилке предопределён
+устройством продукта, сравнивает варианты и описывает рекомендуемый план с
+привязкой к файлам.
+
+---
+
+## 1. TL;DR
+
+1. **Нативного приложения нет.** В проекте отсутствуют Capacitor, React Native,
+   Cordova и т.п. Мобильного клиента ещё не начинали.
+2. **Адаптивная веб-версия — есть, и довольно проработанная.** Веб-клиент
+   открывается с телефона как mobile-friendly сайт: сворачиваемый сайдбар-drawer,
+   отдельные мобильные компоненты (история, поиск, хлебные крошки), responsive-
+   примитивы Mantine, mobile-tuned `viewport`. Это готовый фундамент UI.
+3. **Ядро продукта — веб-редактор — нативно не воспроизвести.** TipTap 3
+   (ProseMirror) + совместное редактирование на Yjs/Hocuspocus плотно сшиты с
+   React. Production-порта Yjs под Swift/Kotlin нет. Любой реалистичный путь
+   оставляет редактор в **WebView**.
+4. **API уже готов к нативному клиенту.** Сервер принимает JWT не только из
+   cookie, но и из заголовка `Authorization: Bearer`. Есть точка входа для
+   вебсокета совместного редактирования (`POST /auth/collab-token`).
+5. **Рекомендуемый путь — Capacitor:** обернуть существующий React-SPA в
+   нативную оболочку (iOS + Android из одного кода), добавить нативные плагины
+   (push, биометрия, share, файлы). Эволюция в гибрид (нативная навигация +
+   WebView-редактор) делается потом инкрементально, без переписывания.
+6. **Оффлайн-будущее уже заложено** (Yjs + `y-indexeddb`). Детальный план
+   оффлайн-синхронизации (этапы M0…M4) ведётся отдельно; мобильное приложение
+   этот план переиспользует, а не дублирует.
+7. **Главный блокер — не технический, а лицензионный.** AGPL форка несовместима
+   с условиями App Store, если зашивать веб-клиент в бинарник: DRM/usage-rules
+   Apple = «дополнительные ограничения», запрещённые AGPLv3 §10. Развязки —
+   грузить клиент с сервера (не из `.ipa`), PWA или sideload. Детали и матрица —
+   в §9; закрывать **до** кода обёртки.
+
+---
+
+## 2. Текущее состояние (как есть)
+
+### 2.1. Стек
+
+| Слой | Технологии |
+|---|---|
+| Бэкенд | NestJS 11 + Fastify, Kysely/Postgres, Redis/BullMQ. API в стиле RPC-POST (соглашение Docmost). Аутентификация — JWT. |
+| Фронт | React 18 + Vite + Mantine + TanStack Query + i18next. Обычный SPA. |
+| Ядро (редактор) | TipTap 3 (ProseMirror) + совместное редактирование на Yjs через Hocuspocus — см. [page-editor.tsx](../apps/client/src/features/editor/page-editor.tsx). |
+| Оффлайн-фундамент | `yjs` + `y-indexeddb` уже в зависимостях клиента (локальная CRDT-копия тела документа). |
+
+### 2.2. Мобильного приложения нет
+
+В `package.json` и `apps/*/package.json` нет `capacitor`, `react-native`,
+`cordova`, `expo`. Нативной оболочки в репозитории не заведено.
+
+### 2.3. Адаптивная веб-версия — есть
+
+| Что | Где |
+|---|---|
+| Адаптивная оболочка Mantine `AppShell` с `breakpoint: "sm"`, раздельные состояния `collapsed.mobile` / `collapsed.desktop` | [global-app-shell.tsx](../apps/client/src/components/layouts/global/global-app-shell.tsx) (L85–99) |
+| Отдельный мобильный сайдбар-drawer (`mobileSidebarAtom` отделён от `desktopSidebarAtom`), авто-закрытие при навигации по дереву | [sidebar-atom.ts](../apps/client/src/components/layouts/global/hooks/atoms/sidebar-atom.ts), [space-tree-row.tsx](../apps/client/src/features/page/tree/components/space-tree-row.tsx) (L147–148) |
+| Мобильная модалка истории + свой CSS | [history-modal.tsx](../apps/client/src/features/page-history/components/history-modal.tsx) (L17–19), `history-modal-mobile.tsx` |
+| Мобильный контрол поиска | [search-control.tsx](../apps/client/src/features/search/components/search-control.tsx) (L38–42) |
+| Мобильный рендер хлебных крошек через `useMediaQuery` | [breadcrumb.tsx](../apps/client/src/features/page/components/breadcrumbs/breadcrumb.tsx) (L41) |
+| Responsive-примитивы `hiddenFrom`/`visibleFrom` (~16 мест), медиа-запросы в CSS-модулях | по всему `apps/client/src` |
+| Mobile-tuned viewport (`width=device-width, user-scalable=no`) | [index.html](../apps/client/index.html) (L8) |
+
+> Важно: адаптив проверялся в мобильном **браузере**, а не в WebView нативной
+> оболочки. Перед сборкой приложения нужно прогнать UI как PWA/в WebView и
+> отловить отличия (жесты, экранная клавиатура/IME в редакторе, safe-area).
+
+### 2.4. Готовность API к нативному клиенту
+
+- **Bearer-токен уже поддержан.** JWT извлекается из cookie **или** из заголовка
+  `Authorization`: см. [jwt.strategy.ts](../apps/server/src/core/auth/strategies/jwt.strategy.ts) (L27–29).
+  Серверная сторона нативной авторизации менять не нужно. (Подтверждено
+  мобильным бутстрапом.)
+- **Токен можно вернуть в теле логина (opt-in).** [`login`](../apps/server/src/core/auth/auth.controller.ts)
+  по-прежнему кладёт JWT в `httpOnly`-cookie, а при флаге `returnToken` дополнительно
+  возвращает его в теле ответа (`data.authToken`) для нативных клиентов; веб-клиент
+  остаётся на cookie. Реализовано мобильным бутстрапом.
+- **Точка входа вебсокета коллаборации:** [`POST /auth/collab-token`](../apps/server/src/core/auth/auth.controller.ts) (L187–193).
+  (Подтверждено мобильным бутстрапом.)
+- **CORS — явный allowlist.** Вместо безусловного `app.enableCors()` теперь
+  настраиваемый whitelist через `CORS_ALLOWED_ORIGINS` плюс автоматически
+  разрешённые нативные WebView-origin'ы (Capacitor/Ionic/localhost). Реализовано
+  мобильным бутстрапом.
+- **OpenAPI/Swagger — опционально.** Swagger UI доступен на `/api/docs` за флагом
+  `SWAGGER_ENABLED` (по умолчанию выключен), что даёт авто-генерацию типизированного
+  клиента. Реализовано мобильным бутстрапом.
+
+---
+
+## 3. Почему путь к мобилке предопределён
+
+Три факта диктуют решение независимо от моды:
+
+1. **Редактор практически невозможно переписать нативно.** ProseMirror + весь
+   набор TipTap-расширений + Yjs-CRDT — это не «поле ввода». Нативного
+   production-порта Yjs под Swift/Kotlin нет (есть Rust `yrs` с биндингами, но
+   это отдельный тяжёлый проект). Переписывание ядра нативно = годы и вечное
+   расхождение с веб-версией. **Вывод: редактор остаётся в WebView.**
+2. **API уже умеет нативного клиента** (Bearer, collab-token).
+3. **Оффлайн-фундамент уже заложен** на веб-уровне (Yjs + `y-indexeddb`),
+   и он работает внутри WebView.
+
+---
+
+## 4. Три возможных пути
+
+| Путь | Суть | Плюсы | Минусы | Вердикт |
+|---|---|---|---|---|
+| **A. Полностью нативно** (Swift/Kotlin) | Переписать всё, включая редактор и CRDT-синк | Максимально нативный UX | Воспроизвести ProseMirror + расширения + Yjs; несоразмерные трудозатраты; вечное отставание от веба | ❌ Не наш случай |
+| **B. WebView-обёртка SPA (Capacitor)** | Обернуть существующий React-клиент в нативную оболочку, native-возможности — плагинами | Реюз ~100% кода (редактор, коллаборация, оффлайн); один кодовый бэйз → iOS+Android; быстро | Менее «нативно»; риск отказа App Store за «просто сайт» (4.2) — лечится нативной ценностью | ✅ Рекомендуется |
+| **C. Гибрид: нативная оболочка + WebView-редактор** | Навигация/списки/поиск/логин — нативно (React Native/Swift), экран редактирования — web в WebView | Лучший UX; путь Notion/Linear | Заметно больше работы; нужен мост JS↔native | ⚖️ Цель эволюции из B |
+
+---
+
+## 5. Рекомендуемый путь
+
+**B (Capacitor) как первый релиз, с заложенной эволюцией в C.**
+
+Почему:
+- Capacitor создан под сценарий «есть веб-приложение → хочу его в App Store с
+  нативными возможностями». Переиспользуется весь React-клиент и, главное,
+  редактор — то, что нативно не сделать.
+- Один кодовый бэйз закрывает «iOS обязательно» и «Android как пойдёт»
+  одновременно, без второй команды.
+- Адаптивная вёрстка уже есть (см. §2.3) — переверстывать под телефон с нуля
+  не нужно; работа смещается в нативную обвязку.
+- Оффлайн-будущее подготовлено (Yjs + `y-indexeddb`); оффлайн-синхронизация
+  ведётся отдельным планом (этапы M0…M4).
+- Когда упрётесь в UX отдельных экранов — их по одному выносят в нативную
+  оболочку, оставив редактор в WebView. То есть B → C делается инкрементально.
+
+Почему **не** чистый React Native сразу: редактор всё равно придётся держать в
+WebView (ядро web-only), но при этом теряется прямой реюз остального React-кода
+и появляется мост как обязательная сложность с первого дня — для iOS-first
+старта это лишний оверхед.
+
+> Альтернатива: если критичен максимально нативный UX с первого релиза и есть
+> ресурс — сразу путь C на React Native (Expo) с WebView только под редактор.
+> Это сознательный размен «больше работы сейчас» за «более нативное ощущение».
+
+⚠️ **Лицензионная оговорка к iOS.** Обычный Capacitor зашивает веб-билд
+`apps/client` в `.ipa` — для публикации в App Store это **нарушает AGPL**
+(см. §9). Выбор Capacitor для **Android** остаётся в силе, но на **iOS**
+веб-клиент нельзя бандлить в бинарник: либо грузить его с сервера
+(`server.url`), либо PWA. То есть рекомендация «B (Capacitor)» применима к
+Android как есть, а к iOS — только в конфигурации без зашитого AGPL.
+
+---
+
+## 6. Что доработать на бэкенде
+
+Немного, но конкретно:
+
+1. **Выдача токена в теле ответа для нативного хранения.** Сейчас логин кладёт
+   JWT только в `httpOnly`-cookie и не возвращает его в body. На мобиле
+   `httpOnly`-cookie между разными origin (`capacitor://localhost` ↔ API) — боль
+   с SameSite/CORS. Чище: мобильный логин-флоу, возвращающий JWT в ответе, чтобы
+   хранить его в Keychain/Keystore и слать как `Authorization: Bearer`. Сервер
+   уже принимает Bearer — менять надо только **выдачу**.
+   Файлы: [auth.controller.ts](../apps/server/src/core/auth/auth.controller.ts).
+2. **CORS.** Сейчас [`app.enableCors()`](../apps/server/src/main.ts) (L144) без
+   конфигурации. Под мобильные origin'ы и для безопасности задать явный whitelist.
+3. **Push-уведомления.** Модуль `notification` уже есть — добавить регистрацию
+   device-token и интеграцию **APNs** (iOS) / **FCM** (Android).
+4. **Опционально — OpenAPI/Swagger.** Сейчас спецификации нет; добавить
+   `@nestjs/swagger` дёшево и сильно ускорит мобильную разработку
+   (типизированный клиент).
+
+---
+
+## 7. Android-специфика
+
+На пути Capacitor Android едет почти бесплатно (`npx cap add android` из того же
+веб-билда), но есть нюансы:
+
+- **Движок в плюс.** Android System WebView (Chromium) обновляется через Play
+  Store независимо от ОС и обычно свежее iOS WKWebView. Более рискованный движок
+  по совместимости — это iOS, а не Android.
+- **Фрагментация.** Дешёвые/старые устройства с малой памятью и устаревшим
+  WebView; стек тяжёлый (ProseMirror + Yjs + mermaid + katex + excalidraw) —
+  тестировать на бюджетных аппаратах.
+- **Обвязка под Android:** аппаратная/жестовая кнопка «Назад» (навигация внутри
+  приложения, а не выход), **FCM** для push, Android App Links (вместо iOS
+  Universal Links), подписание и Play Console.
+- **Главный риск именно для Android — ввод текста в ProseMirror на Gboard/IME.**
+  Историческая боль `contenteditable` на Android (прыжки курсора, дубли символов
+  при композиции). Стало лучше, но **проверять в первую очередь и рано**.
+- **Магазин.** Google Play лояльнее к webview-обёрткам, чем App Store; риск
+  «отклонят как просто сайт» для Play практически неактуален.
+
+---
+
+## 8. iOS-специфика
+
+- **WKWebView** на движке WebKit жёстко привязан к версии ОС — это более
+  рискованный по совместимости движок (тестировать прежде всего его).
+- **App Store guideline 4.2 (minimum functionality).** Чистая webview-обёртка
+  рискует отклонением «это просто сайт». Лечится реальной нативной ценностью:
+  push, share-extension, биометрический разблок, оффлайн-кэш — всё это Capacitor
+  даёт плагинами.
+- **safe-area** под «чёлку»/системные панели, поведение экранной клавиатуры в
+  редакторе.
+
+---
+
+## 9. Лицензионный блокер: AGPL ↔ App Store (iOS)
+
+> Это не инженерная, а **лицензионная** задача — закрывать её надо **до** кода
+> обёртки, иначе можно сделать приложение, которое некуда легально опубликовать.
+> Ниже — инженерно-лицензионный разбор, **не** юридическая консультация; финально
+> подтверждать у того, кто разбирается в лицензиях.
+
+### 9.1. Суть конфликта
+
+gitmost — форк Docmost под **AGPL-3.0** (константа форка: «100% open, AGPL-only»).
+Две вещи несовместимы:
+
+- **AGPLv3 §10** (последний абзац) запрещает накладывать на получателя кода
+  **любые дополнительные ограничения** сверх самой лицензии.
+- **Стандартный EULA App Store** ровно их и накладывает: **FairPlay/DRM**,
+  привязка установки к Apple ID с лимитом устройств (**usage rules**), запрет
+  свободного перераспространения бинарника.
+
+Приняв условия Apple, чтобы попасть в App Store, вы нарушаете AGPL кода, который
+раздаёте.
+
+### 9.2. Почему это бьёт именно по форку
+
+Запрет «дополнительных ограничений» связывает **лицензиатов, но не самого
+правообладателя**: владелец 100% копирайта может опубликовать свой код в App Store.
+Но в gitmost бóльшая часть копирайта принадлежит **upstream-Docmost** и
+контрибьюторам — вы выступаете дистрибьютором *чужого* AGPL-кода и не можете
+единолично добавить App-Store-исключение.
+
+Прецеденты: **VLC** (удалён из App Store в 2011 по жалобе на конфликт GPL с
+условиями стора; вернулся только после перелицензирования и согласия
+правообладателей), **GNU Go** — снят по той же причине. Это не теоретический риск.
+
+### 9.3. Ключевой принцип развязки: лицензия смотрит на `.ipa`, а не на устройство
+
+Определяющее — **что раздаёт сам Apple** (`.ipa` под FairPlay) и **кто раздаёт
+AGPL-байты**, а не то, окажутся ли они в итоге на устройстве:
+
+- AGPL **внутри `.ipa`** → получен под ограничениями Apple → **нарушение**.
+- AGPL **скачан с вашего сервера** → получен от вас под AGPL (исходники открыты,
+  §13 выполнен) → ограничения Apple на него **не** накладываются, даже если бандл
+  кэшируется в песочнице приложения.
+
+Следствие: **офлайн на iOS легально достижим** — если кэшированный бандл пришёл с
+вашего сервера, а не из `.ipa`. Ограничение тут не лицензионное, а в **ревью
+Apple** (см. §9.5).
+
+### 9.4. Варианты «грузить веб-клиент с сервера»
+
+**A. WebView навигируется на хостед-клиент (`server.url`).** Capacitor умеет
+`server: { url: 'https://app.example.com' }` — оболочка грузит WebView с удалённого
+URL, мост и нативные плагины по-прежнему инжектятся. В `.ipa` — ноль AGPL.
+
+- Плюс: лицензионно самый чистый; **origin = ваш домен**, поэтому cookie/CORS
+  работают как в браузере (боль `capacitor://localhost` ↔ API из §6 исчезает —
+  токен в body/Keychain может и не понадобиться).
+- Минус: холодный старт требует сети; сервер лёг → приложение кирпич; офлайна по
+  умолчанию нет.
+
+**B. OTA: пустой шелл скачивает и кэширует бандл.** Шелл при первом запуске тянет
+JS-бандл с вашего сервера и кэширует как веб-ассеты (механизм Cordova/CodePush).
+Open-source self-host-вариант — `@capgo/capacitor-updater` (важно для AGPL-проекта:
+без привязки к проприетарному Appflow).
+
+- Плюс: **даёт офлайн** — кэш AGPL легален, т.к. распространён вами, а не Apple.
+- Минус: упирается в политику Apple по hot-update (§9.5).
+
+**Не-обходы (мифы):** «никто не засудит» — это нарушение, а не обход; «LGPL-нуть
+обёртку» — не помогает (проблема в AGPL-веб-клиенте, а не в обёртке); «mere
+aggregation» — не катит: зашитый бандл это комбинированное распространяемое
+произведение, а не простая агрегация.
+
+### 9.5. Гейты Apple
+
+| # | Guideline | Суть | Влияние |
+|---|---|---|---|
+| 1 | **2.5.2** (исполняемый код) | Скачивать/исполнять **нативный** код нельзя, **но** есть исключение для скриптов, исполняемых встроенным WebKit/JavascriptCore, если они не меняют назначение приложения | Загрузка веб-клиента в `WKWebView` под исключение попадает: вариант A — чистый, B — терпимый, но с границами |
+| 2 | **4.2** (minimum functionality) | Чистый WebView-«просто сайт» рискует отклонением | Лечится нативной ценностью в оболочке (push/APNs, биометрия, share, файлы — ваш нативный код, не AGPL) |
+| 3 | конфликт двух гейтов | «Лицензионно чистый» вариант (пустой шелл качает всё) — самый рискованный для ревью; «безопасный для ревью» (зашить веб-билд в `.ipa`) — лицензионное нарушение | **Совместить (офлайн) + (чистая AGPL) + (низкий риск ревью) в одной конфигурации нельзя — выбираете любые два** |
+
+Безопасность: раз исполняете удалённый код — только HTTPS, желательно cert-pinning
+(подмена сервера = произвольный JS в WebView пользователя).
+
+### 9.6. Итоговая матрица распространения iOS
+
+| Конфигурация | AGPL-чистота | Офлайн | Риск ревью Apple |
+|---|---|---|---|
+| A. `server.url` на хостед-клиент | ✅ чистая | ❌ нет | средний (4.2, лечится плагинами) |
+| B. OTA пустой шелл + кэш бандла | ✅ чистая | ✅ есть | выше (2.5.2 + 4.2) |
+| Зашить веб-билд в `.ipa` (обычный Capacitor) | ❌ нарушение | ✅ | низкий |
+| **PWA** | ✅ чистая | ✅ | App Store не нужен |
+| Sideload / EU DMA-маркетплейсы (iOS 17.4+) | ✅ чистая | ✅ | вне App Store; **только ЕС** |
+
+**Вывод:** для iOS **PWA** — самое дешёвое решение, закрывающее всё сразу. Если
+присутствие именно в App Store критично — **вариант A** (`server.url` + нативные
+плагины под 4.2) легальный и реалистичный ценой «онлайн для холодного старта».
+Офлайн в App Store (вариант B) технически и лицензионно возможен, но это
+максимальный риск на ревью — закладывать только если офлайн на iOS обязателен.
+Совместить «App Store + зашитый офлайн AGPL» легально нельзя, пока копирайт не ваш.
+
+---
+
+## 10. Оффлайн в будущем
+
+Оффлайн сейчас не требуется, но позиция хорошая:
+
+- Тело документа уже редактируется через Yjs (CRDT) + `y-indexeddb` — локальная
+  копия и автослияние правок работают, в том числе в WebView.
+- «Полностью онлайн» — это всё вокруг тела (навигация, заголовки, комментарии,
+  CRUD, вложения, авторизация). Их оффлайн-синхронизация описана отдельным
+  планом с этапами M0…M4.
+- Мобильное приложение **переиспользует** этот план, а не строит оффлайн заново.
+  Нюанс Android: System WebView под нехваткой места может чистить хранилище →
+  для оффлайна, возможно, понадобится дублировать критичные данные в нативное
+  хранилище, чтобы локальные копии не вычищались.
+
+---
+
+## 11. Открытые вопросы (зафиксировать до старта)
+
+- **Q1.** Путь: Capacitor (B) с эволюцией в гибрид, или сразу React Native (C)?
+  Рекомендация — B.
+- **Q2.** Мобильная авторизация: отдельный логин-флоу с токеном в body + Keychain/
+  Keystore + Bearer (рекомендуется) или попытка работать через cookie в WebView?
+- **Q3.** Push: APNs + FCM сразу или iOS-first?
+- **Q4.** Подключать ли OpenAPI/Swagger для генерации мобильного клиента?
+- **Q5.** Когда включать оффлайн (этапы M0…M4) относительно
+  первого мобильного релиза?
+- **Q6.** iOS-дистрибуция при AGPL (§9): App Store через `server.url`
+  (онлайн-клиент, без зашитого AGPL), PWA или sideload/EU-маркетплейсы? Этот
+  лицензионный путь нужно подтвердить **до** кода обёртки. Рекомендация — PWA для
+  iOS, Capacitor для Android.
+
+---
+
+## 12. Чеклист первого шага (бутстрап Capacitor, iOS-first)
+
+- [ ] **Закрыть лицензионный путь iOS (§9) ДО кода обёртки:** выбрать
+      `server.url` / PWA / sideload и подтвердить у разбирающегося в лицензиях.
+- [ ] **Не бандлить AGPL-веб-клиент в iOS `.ipa`** (DRM/usage-rules App Store ⟂
+      AGPLv3 §10) — на iOS грузить клиент с сервера или идти через PWA.
+- [ ] Прогнать существующий адаптивный UI как PWA/в WebView, отловить отличия
+      (жесты, IME в редакторе, safe-area).
+- [x] Добавить Capacitor в монорепо, нацелить на веб-билд `apps/client`
+      (Android — зашитый билд; iOS — `server.url`/PWA без зашитого AGPL, см. §9).
+- [ ] `npx cap add ios` (Android — `npx cap add android`, когда будет готова обвязка) — нативные проекты генерируются локально и намеренно не хранятся в VCS (см. §9).
+- [x] Бэкенд: мобильный логин-флоу с токеном в body; хранить токен в Keychain/
+      Keystore; слать `Authorization: Bearer`.
+- [x] Бэкенд: явный CORS-whitelist под мобильные origin'ы.
+- [ ] Native-плагины под App Store 4.2: push, биометрия, share, файлы.
+- [ ] Push: APNs (iOS); FCM добавить вместе с Android.
+- [ ] Проверить вебсокет коллаборации из WebView (`/auth/collab-token` + Hocuspocus).
+- [x] (Опционально) Подключить `@nestjs/swagger`.

docs/mobile-bootstrap.md

@@ -0,0 +1,61 @@
+# Mobile app bootstrap
+
+Purpose: this document records what has been bootstrapped in the repo to enable a
+mobile app for Gitmost, per the first-step checklist in
+[docs/mobile-app-plan.md](./mobile-app-plan.md) section 12.
+
+## What is in the repo now
+
+- **PWA**: web app manifest plus a service worker generated by `vite-plugin-pwa`
+  using Workbox (`strategies: "generateSW"` — not hand-rolled). The SW is built
+  for production only (`devOptions: { enabled: false }`) and uses
+  `registerType: "prompt"`, so the user is asked to apply an update rather than it
+  auto-updating; registration goes through `virtual:pwa-register/react`
+  (`useRegisterSW`) in `apps/client/src/pwa/pwa-update-prompt.tsx`, mounted from
+  `main.tsx` and skipped inside the Capacitor native WebView. The SW precaches the
+  app shell (`globPatterns` js/css/html/...) and serves `navigateFallback:
+  "index.html"` for SPA routes, with `navigateFallbackDenylist` excluding the
+  server-owned routes `/api`, `/collab`, `/socket.io`, `/share/`, `/mcp`, and
+  `/robots.txt`. `runtimeCaching` keeps `/collab`, `/socket.io`, and all `/api`
+  as `NetworkOnly` — offline reads are served by the persisted TanStack Query
+  cache (IndexedDB) and `y-indexeddb` for the page Yjs doc, not by an SW HTTP
+  cache. This lets the existing responsive web UI be installed and run as a
+  Progressive Web App. The offline/sync design (stages M0…M4) is summarized in
+  [mobile-app-plan.md](./mobile-app-plan.md).
+- **Backend mobile auth**: opt-in token return from the login flow. The login
+  request accepts a `returnToken` flag (must be sent as a JSON boolean) that makes
+  the server include the auth token in the response body, and the server already
+  accepts a `Bearer` token in the `Authorization` header. Note the global response
+  interceptor wraps every payload, so the native client reads the token at
+  `response.data.authToken` (not at the top level). A native client can store this
+  token (Keychain / Keystore) and send it as `Authorization: Bearer` on each request.
+- **Explicit CORS allowlist**: the server reads a `CORS_ALLOWED_ORIGINS` env
+  variable for the allowed origins, and always allows the native WebView origins
+  (`capacitor://localhost`, `ionic://localhost`, `https://localhost`) so the
+  mobile shell can call the API.
+- **Optional OpenAPI / Swagger**: an opt-in OpenAPI/Swagger surface gated behind
+  the `SWAGGER_ENABLED` env flag, useful for developing the native client.
+- **Capacitor config**: [capacitor.config.ts](../capacitor.config.ts) at the
+  repo root. It targets the `apps/client` web build output (`apps/client/dist`)
+  for the Android bundled mode, and on iOS loads the client from a hosted server
+  via `CAP_SERVER_URL` (`server.url`) so the AGPL web client is not bundled into
+  the `.ipa` (see mobile-app-plan section 9).
+
+## Remaining MANUAL / local steps (require Xcode / external accounts, out of scope here)
+
+- Run `pnpm install` to fetch the Capacitor packages and `@nestjs/swagger`.
+- Run `pnpm run client:build` to produce the web build in `apps/client/dist`.
+- Run `npx cap add ios` and/or `npx cap add android` to generate the native
+  platform projects (these live outside version control; see `.gitignore`).
+- Set `CAP_SERVER_URL` for the iOS build so the shell loads the hosted client
+  (AGPL-clean), then run `pnpm run mobile:build` / `cap sync`.
+- Set up push notifications: APNs for iOS and FCM for Android.
+- Obtain an Apple Developer account and the App Store / Play Console listings.
+- Confirm the AGPL iOS distribution decision (mobile-app-plan section 9) before
+  shipping anything to the App Store.
+
+## See also
+
+For the full background, rationale, and the licensing analysis, see
+[docs/mobile-app-plan.md](./mobile-app-plan.md) (section 12 for the bootstrap
+checklist, section 9 for the AGPL / App Store licensing path).

package.json

@@ -16,10 +16,18 @@
     "server:start": "nx run server:start:prod",
     "email:dev": "nx run server:email:dev",
     "dev": "pnpm concurrently -n \"frontend,backend\" -c \"cyan,green\" \"pnpm run client:dev\" \"pnpm run server:dev\"",
-    "clean": "rm -rf apps/*/dist packages/*/dist apps/client/node_modules/.vite"
+    "clean": "rm -rf apps/*/dist packages/*/dist apps/client/node_modules/.vite",
+    "cap:copy": "cap copy",
+    "cap:sync": "cap sync",
+    "cap:ios": "cap open ios",
+    "cap:android": "cap open android",
+    "mobile:build": "pnpm run client:build && cap sync"
   },
   "dependencies": {
     "@braintree/sanitize-url": "^7.1.2",
+    "@capacitor/android": "^7.0.0",
+    "@capacitor/core": "^7.0.0",
+    "@capacitor/ios": "^7.0.0",
     "@casl/ability": "6.8.0",
     "@docmost/editor-ext": "workspace:*",
     "@floating-ui/dom": "^1.7.3",
@@ -78,6 +86,7 @@
     "yjs": "^13.6.30"
   },
   "devDependencies": {
+    "@capacitor/cli": "^7.0.0",
     "@nx/js": "22.6.1",
     "@types/bytes": "^3.1.5",
     "@types/qrcode": "^1.5.6",