fix(mcp): write page body before title to avoid split-brain on failure (#159)

updatePage (markdown) and updatePageJson wrote the title via REST FIRST, then
the body via collab. If the body write failed (e.g. a collab persist timeout),
the page was left with the NEW title over its OLD body — a split-brain the tool
reported as an error but never repaired (red-team finding #10).

Reorder both: write the body first, and only set the title after the body has
persisted. Now a body-write failure leaves the title untouched (no split-brain).
A title write failing after a successful body is rarer (REST is fast) and leaves
correct content under a stale title — the strictly lesser inconsistency — which
is the same trade-off the issue's "atomic, or roll back the title" intends,
without the fragility of a rollback write that could itself fail.

No unit test: both paths require a live collab provider and the suite has no
provider mock; the change is a pure reordering. All 306 mcp tests still pass.

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

.github/workflows/test.yml

@@ -15,6 +15,38 @@ permissions:
 jobs:
   test:
     runs-on: ubuntu-latest
+    # Real Postgres + Redis so the server integration suite (`*.int-spec.ts`,
+    # behind `pnpm --filter server test:int`) runs in CI (red-team finding #7).
+    # Without it, cost-cap / FK-cascade / jsonb-round-trip / real-apply tests
+    # only ran locally, so regressions in those paths stayed green in CI.
+    # Postgres uses the pgvector image because migrations create vector columns
+    # and global-setup runs `CREATE EXTENSION vector`. Credentials/db match the
+    # defaults in apps/server/test/integration/db.ts + global-setup.ts
+    # (docmost / docmost_dev_pw, maintenance db `docmost`, redis on 6379), so no
+    # TEST_*_URL overrides are needed.
+    services:
+      postgres:
+        image: pgvector/pgvector:pg16
+        env:
+          POSTGRES_USER: docmost
+          POSTGRES_PASSWORD: docmost_dev_pw
+          POSTGRES_DB: docmost
+        ports:
+          - 5432:5432
+        options: >-
+          --health-cmd "pg_isready -U docmost"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+      redis:
+        image: redis:7
+        ports:
+          - 6379:6379
+        options: >-
+          --health-cmd "redis-cli ping"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -36,5 +68,12 @@ jobs:
       - name: Build editor-ext
         run: pnpm --filter @docmost/editor-ext build
 
-      - name: Run tests
+      - name: Run unit tests
         run: pnpm -r test
+
+      # Integration suite against the real Postgres/Redis services above. Runs
+      # the FK-cascade, cost-cap, jsonb-round-trip and real-apply specs that the
+      # unit run (mocks only) cannot cover. global-setup drops/recreates the
+      # isolated `docmost_test` DB and migrates it to latest.
+      - name: Run server integration tests
+        run: pnpm --filter server test:int

CHANGELOG.md

@@ -12,21 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- **Persistent AI-chat history as the source of truth + server-side export.**
-  An assistant turn is now persisted to the database step by step: the row is
-  inserted upfront as `streaming` and updated as each agent step finishes, then
-  finalized once to `completed`/`error`/`aborted`. A process that dies mid-turn
-  keeps every finished step, and a startup sweep flips any dangling `streaming`
-  row (untouched for 10 minutes) to `aborted`. Chat "Copy" now exports
-  server-side from these rows (`POST /ai-chat/export`) rather than from live
-  client state, so the export is identical whether a chat is freshly streaming,
-  just switched to, or reloaded — and is available from the first turn of a new
-  chat. (#183, #174)
-
 - **AI-agent attribution for MCP writes.** Comments (and pages) created through
   the MCP endpoint by a dedicated agent account are now badged as "AI", with
   unspoofable provenance derived from a per-user `is_agent` flag (not from the
-  request body). **Operator setup:** use a _dedicated_ service account for the
+  request body). **Operator setup:** use a *dedicated* service account for the
   MCP fallback and set the flag with SQL —
   `UPDATE users SET is_agent = true WHERE email = '<mcp-account>'`. Never flag a
   human or shared account, or its normal edits get mis-attributed as AI. See the
@@ -161,7 +150,8 @@ embeds — plus a large batch of security hardening and test coverage.
 - Page templates: import `ThrottleModule` so collab boots, never strand an
   in-flight page-embed id, and add defense-in-depth workspace checks.
 - Pages: `movePage` cycle guard with no phantom `PAGE_MOVED` event.
-- Import: surface the real error cause from `/pages/import` instead of a generic 400.
+- Import: surface the real error cause from `/pages/import` instead of a generic
+  400.
 
 ### Security
 

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

@@ -258,7 +258,6 @@
   "Copy to space": "Copy to space",
   "Copy chat": "Copy chat",
   "Copied": "Copied",
-  "Failed to export chat": "Failed to export chat",
   "Duplicate": "Duplicate",
   "Select a user": "Select a user",
   "Select a group": "Select a group",
@@ -711,6 +710,7 @@
   "Authorization header": "Authorization header",
   "Tool allowlist": "Tool allowlist",
   "Optional. Leave empty to allow all tools the server exposes.": "Optional. Leave empty to allow all tools the server exposes.",
+  "Optional guidance for the agent on how and when to use this server's tools. Injected into the system prompt. The server's tools are namespaced as \"<server name>_*\".": "Optional guidance for the agent on how and when to use this server's tools. Injected into the system prompt. The server's tools are namespaced as \"<server name>_*\".",
   "Test": "Test",
   "Available tools": "Available tools",
   "No tools available": "No tools available",

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

@@ -257,7 +257,6 @@
   "Copy": "Копировать",
   "Copy to space": "Копировать в пространство",
   "Copied": "Скопировано",
-  "Failed to export chat": "Не удалось экспортировать чат",
   "Duplicate": "Дублировать",
   "Select a user": "Выберите пользователя",
   "Select a group": "Выберите группу",
@@ -406,6 +405,8 @@
   "Footnote {{number}}": "Сноска {{number}}",
   "Go to footnote": "Перейти к сноске",
   "Back to reference": "Вернуться к ссылке",
+  "Back to references": "Вернуться к ссылкам",
+  "Back to reference {{label}}": "Вернуться к ссылке {{label}}",
   "Empty footnote": "Пустая сноска",
   "Math inline": "Строчная формула",
   "Insert inline math equation.": "Вставить математическое выражение в строку.",
@@ -750,6 +751,8 @@
   "Manage API keys for all users in the workspace. View the <anchor>API documentation</anchor> for usage details.": "Управляйте API-ключами для всех пользователей в рабочем пространстве. Смотрите <anchor>документацию по API</anchor> для получения информации об использовании.",
   "View the <anchor>API documentation</anchor> for usage details.": "Смотрите <anchor>документацию по API</anchor> для получения информации об использовании.",
   "View the <anchor>MCP documentation</anchor>.": "Смотрите <anchor>документацию по MCP</anchor>.",
+  "Instructions": "Инструкции",
+  "Optional guidance for the agent on how and when to use this server's tools. Injected into the system prompt. The server's tools are namespaced as \"<server name>_*\".": "Необязательное указание агенту, как и когда использовать инструменты этого сервера. Добавляется в системный промпт. Инструменты сервера именуются с префиксом «<имя сервера>_*».",
   "Sources": "Источники",
   "AI Answers not available for attachments": "Ответы ИИ недоступны для вложений",
   "No answer available": "Ответ недоступен",

apps/client/src/features/ai-chat/components/ai-chat-window.tsx

@@ -6,6 +6,7 @@ import {
   useRef,
   useState,
 } from "react";
+import { type UIMessage } from "@ai-sdk/react";
 import { Group, Loader, Tooltip } from "@mantine/core";
 import {
   IconArrowsDiagonal,
@@ -39,7 +40,7 @@ import {
 } from "@/features/ai-chat/queries/ai-chat-query.ts";
 import ConversationList from "@/features/ai-chat/components/conversation-list.tsx";
 import ChatThread from "@/features/ai-chat/components/chat-thread.tsx";
-import { exportAiChat } from "@/features/ai-chat/services/ai-chat-service.ts";
+import { buildChatMarkdown } from "@/features/ai-chat/utils/chat-markdown.ts";
 import { useChatSession } from "@/features/ai-chat/hooks/use-chat-session.ts";
 import {
   shouldCollapseOnOutsidePointer,
@@ -120,7 +121,7 @@ function clampGeom(g: {
  * ported from the GitmostAgent.jsx design.
  */
 export default function AiChatWindow() {
-  const { t, i18n } = useTranslation();
+  const { t } = useTranslation();
   const clipboard = useClipboard({ timeout: 500 });
   const queryClient = useQueryClient();
   const [windowOpen, setWindowOpen] = useAtom(aiChatWindowOpenAtom);
@@ -161,11 +162,30 @@ export default function AiChatWindow() {
   const { data: messageRows, isLoading: messagesLoading } =
     useAiChatMessagesQuery(activeChatId ?? undefined);
 
+  // Live snapshot of the active thread's useChat state, kept up to date by
+  // ChatThread. Lets the export include the in-progress (not-yet-persisted)
+  // streaming turn. A ref avoids re-rendering this window on every token.
+  const liveThreadRef = useRef<{
+    messages: UIMessage[];
+    isStreaming: boolean;
+    banner: string | null;
+  }>({
+    messages: [],
+    isStreaming: false,
+    banner: null,
+  });
+
   // Live turn-token total (reasoning + output) for the in-flight turn, pushed up
   // (THROTTLED to ~8 Hz inside ChatThread) so the header badge ticks mid-stream.
   // `null` means no turn is in flight -> the badge falls back to the persisted
   // context size below.
   const [liveTurnTokens, setLiveTurnTokens] = useState<number | null>(null);
+  // Whether the on-screen thread currently holds at least one message. Reported
+  // reactively by ChatThread (the live snapshot lives in a non-reactive ref). This
+  // lets the "Copy chat" button stay available for a brand-new, not-yet-persisted
+  // chat whose first turn is in flight or was interrupted — that case has no
+  // persisted rows yet, so a persisted-rows-only gate would hide the button (#174).
+  const [hasLiveContent, setHasLiveContent] = useState(false);
 
   // The page the user is currently viewing. AiChatWindow lives in a pathless
   // parent layout route, so useParams() can't see :pageSlug. Match the full
@@ -194,7 +214,6 @@ export default function AiChatWindow() {
     threadKey,
     waitingForHistory,
     onTurnFinished,
-    onServerChatId,
     cancelPendingAdoption,
   } = useChatSession({
     activeChatId,
@@ -235,19 +254,20 @@ export default function AiChatWindow() {
     [cancelPendingAdoption, setActiveChatId, setDraft, setSelectedRoleId],
   );
 
-  // The active chat object (for its title) and an export gate. The export is now
-  // SERVER-sourced (the DB is the single source of truth — #183): the assistant
-  // row is persisted upfront + per step, so even a brand-new chat whose first
-  // turn is streaming/interrupted has a server row to render. Enable the button
-  // whenever a persisted chat is active (`activeChatId` is set). For a BRAND-NEW
-  // chat that id is adopted EARLY — at the stream's `start` chunk via
-  // onServerChatId (#174) — so the Copy button is available during the first
-  // turn's stream, not only after it terminates.
+  // The active chat object (for its title) and an export gate: only enable the
+  // export button when an existing chat with loaded persisted rows is active.
   const activeChat = useMemo(
     () => chats?.items?.find((c) => c.id === activeChatId) ?? null,
     [chats, activeChatId],
   );
-  const canExport = !!activeChatId;
+  // Export is available when there is anything to export: either persisted rows
+  // for the active chat, OR a live on-screen thread with at least one message.
+  // The live arm covers a brand-new chat whose first turn is streaming or was
+  // interrupted before the server persisted any row (#174); the persisted arm is
+  // the steady-state path for an already-saved chat (#160).
+  const canExport =
+    hasLiveContent ||
+    (!!activeChatId && !!messageRows && messageRows.length > 0);
 
   // The role to display in the header and as the assistant's name. Prefer the
   // persisted role of an existing chat (chat-list JOIN); fall back to the role
@@ -264,21 +284,53 @@ export default function AiChatWindow() {
     return picked ? { name: picked.name, emoji: picked.emoji } : null;
   }, [activeChat, enabledRoles, selectedRoleId]);
 
-  // Fetch the server-rendered Markdown export and copy it to the clipboard. The
-  // server is the single source of truth (#183): it renders the transcript from
-  // the persisted rows — including an interrupted turn's in-progress row — so the
-  // export is identical whether the chat is freshly streaming, just switched to,
-  // or reloaded. The `lang` of the active i18n drives the few localized labels.
-  const handleCopy = useCallback(async () => {
-    if (!activeChatId) return;
-    try {
-      const markdown = await exportAiChat(activeChatId, i18n.language);
-      clipboard.copy(markdown);
-      notifications.show({ message: t("Copied") });
-    } catch {
-      notifications.show({ message: t("Failed to export chat"), color: "red" });
-    }
-  }, [activeChatId, clipboard, t, i18n.language]);
+  // Build a Markdown export from the already-loaded persisted rows (no network
+  // call) and copy it to the clipboard. The "Copied" notification is the
+  // feedback.
+  const handleCopy = useCallback(() => {
+    // Export gate. There must be SOMETHING to export — either a live on-screen
+    // message or a persisted row. A brand-new chat whose first turn is streaming
+    // or was interrupted has live messages but no persisted rows yet; it still
+    // exports the on-screen thread WYSIWYG (#174). Only a truly empty chat (no
+    // live messages and no rows) is non-exportable (the button is hidden too —
+    // see `canExport`).
+    const live = liveThreadRef.current;
+    const hasRows = !!messageRows && messageRows.length > 0;
+    if (live.messages.length === 0 && !hasRows) return;
+    // WYSIWYG export: the live on-screen messages ARE the document (so a partial
+    // reply from an interrupted turn — which never reached the persisted rows —
+    // is exported just as it appears). The persisted rows enrich each live
+    // message (token usage / error / timestamp) by id and serve as the fallback
+    // when the live mirror is empty. The on-screen banner is appended too. See
+    // issues #160 and #174. `chatId` may be null for a not-yet-saved chat — use a
+    // placeholder so the header line still renders.
+    const markdown = buildChatMarkdown({
+      title: activeChat?.title ?? null,
+      chatId: activeChatId ?? "unsaved",
+      live: live.messages.map((m) => ({
+        id: m.id,
+        role: m.role,
+        parts: (m.parts ?? []) as { type: string; text?: string }[],
+        metadata: m.metadata as
+          | {
+              usage?: {
+                inputTokens?: number;
+                outputTokens?: number;
+                totalTokens?: number;
+                reasoningTokens?: number;
+              };
+              error?: string;
+            }
+          | undefined,
+      })),
+      rows: messageRows,
+      isStreaming: live.isStreaming,
+      banner: live.banner,
+      t,
+    });
+    clipboard.copy(markdown);
+    notifications.show({ message: t("Copied") });
+  }, [activeChatId, messageRows, activeChat, clipboard, t]);
 
   // Current context size for the active chat: how much the conversation now
   // occupies in the model's context window — NOT the cumulative tokens spent.
@@ -633,8 +685,9 @@ export default function AiChatWindow() {
               onRolePicked={(role) => setSelectedRoleId(role.id)}
               assistantName={currentRole?.name}
               onTurnFinished={onTurnFinished}
-              onServerChatId={onServerChatId}
+              liveStateRef={liveThreadRef}
               onLiveTurnTokens={setLiveTurnTokens}
+              onLiveContentChange={setHasLiveContent}
             />
           )}
         </div>

apps/client/src/features/ai-chat/components/ai-chat.module.css

@@ -122,7 +122,11 @@
     margin-top: 4px;
     font-size: var(--mantine-font-size-xs);
     color: light-dark(var(--mantine-color-gray-7), var(--mantine-color-dark-1));
-    white-space: pre-wrap;
+    /* NOTE: `white-space: pre-wrap` is intentionally NOT set here. On the
+       rendered markdown <div> it would turn the newlines between block tags
+       (</li>\n<li>, </p>\n<ol>) into visible blank lines/indents on top of the
+       margins. The plain-text fallback <Text> that needs pre-wrap sets it
+       inline itself (see reasoning-block.tsx). */
 }
 
 .reasoningText p {

apps/client/src/features/ai-chat/components/chat-thread.tsx

@@ -1,4 +1,11 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import {
+  useCallback,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+  type MutableRefObject,
+} from "react";
 import { generateId } from "ai";
 import { ActionIcon, Box, Group, Stack, Text } from "@mantine/core";
 import { IconClockHour4, IconX } from "@tabler/icons-react";
@@ -61,18 +68,30 @@ interface ChatThreadProps {
    *  authoritative id the server streamed on the assistant message metadata, or
    *  undefined on a failed turn — see adopt-chat-id.ts for the full #137 design. */
   onTurnFinished: (serverChatId?: string) => void;
-  /** Called EARLY (at the stream's `start` chunk) with the authoritative server
-   *  chat id streamed on the assistant message metadata, so a brand-new chat
-   *  adopts its real id WHILE the first turn is still streaming (#174 — makes the
-   *  Copy/export button available mid-stream). Distinct from onTurnFinished,
-   *  which fires only at the terminal outcome. */
-  onServerChatId?: (serverChatId?: string) => void;
+  /** Parent-owned ref that this thread keeps updated with its live useChat
+   *  snapshot (full message list + streaming flag), so the header's
+   *  "Copy chat" export can include the in-progress, not-yet-persisted
+   *  assistant message. A ref (not state) avoids re-rendering the parent on
+   *  every streamed delta. */
+  liveStateRef?: MutableRefObject<{
+    messages: UIMessage[];
+    isStreaming: boolean;
+    banner: string | null;
+  }>;
   /** Reports the live turn-token total (reasoning + output) for the in-flight
    *  turn so the parent can show a header badge that ticks mid-stream. THROTTLED
    *  here (~8 Hz) so the parent re-renders a handful of times a second, not on
    *  every streamed delta. Called with `null` when no turn is in flight (the
    *  parent then reverts the badge to the persisted context size). */
   onLiveTurnTokens?: (tokens: number | null) => void;
+  /** Reports whether the live thread currently holds at least one message, so the
+   *  parent can gate the "Copy chat" button on the on-screen thread rather than on
+   *  the persisted rows alone. This stays truthy for a brand-new, not-yet-saved
+   *  chat the moment its first user message appears — so an interrupted very first
+   *  turn (no persisted rows yet) is still exportable (#174). Called with `false`
+   *  on unmount so a thread torn down by `key` on chat switch can't leave the
+   *  button enabled for the next, possibly empty, chat. */
+  onLiveContentChange?: (hasContent: boolean) => void;
 }
 
 /**
@@ -116,8 +135,9 @@ export default function ChatThread({
   onRolePicked,
   assistantName,
   onTurnFinished,
-  onServerChatId,
+  liveStateRef,
   onLiveTurnTokens,
+  onLiveContentChange,
 }: ChatThreadProps) {
   const { t } = useTranslation();
 
@@ -286,26 +306,6 @@ export default function ChatThread({
   // Keep the flush helper pointed at the latest sendMessage instance.
   sendMessageRef.current = sendMessage;
 
-  // EARLY chat-id adoption (#174): the server streams the authoritative chat id
-  // on the assistant message metadata at the `start` chunk (message.metadata.
-  // chatId — see adopt-chat-id.ts / chatStreamMetadata). Forward it to the parent
-  // AS SOON AS it appears (mid-stream), so a brand-new chat adopts its real id
-  // WHILE the first turn is still streaming and activeChatId-gated affordances
-  // (the Copy/export button) light up immediately, instead of only at onFinish.
-  // Keyed by the last-seen id so we forward each distinct id exactly once. The
-  // parent's onServerChatId is idempotent and a no-op once the chat has an id.
-  const lastForwardedChatIdRef = useRef<string | undefined>(undefined);
-  useEffect(() => {
-    if (!onServerChatId) return;
-    const tail = messages[messages.length - 1];
-    if (tail?.role !== "assistant") return;
-    const serverChatId = extractServerChatId(tail);
-    if (!serverChatId || serverChatId === lastForwardedChatIdRef.current)
-      return;
-    lastForwardedChatIdRef.current = serverChatId;
-    onServerChatId(serverChatId);
-  }, [messages, onServerChatId]);
-
   // Live "turn was interrupted" marker for the CURRENT session. The red error
   // banner (driven by `error`) covers the error case; this covers an aborted
   // turn, distinguishing a manual Stop (`isAbort`) from a dropped connection
@@ -328,6 +328,44 @@ export default function ChatThread({
   // the SAME on-screen banner text can be mirrored into the export (issue #160).
   const errorView = error ? describeChatError(error.message ?? "", t) : null;
 
+  // The exact banner the user sees under the message list, flattened to a single
+  // string for the "Copy chat" export so the artifact records the interruption
+  // WYSIWYG. Mirrors the JSX precedence below: error first, else the stop notice.
+  const banner = errorView
+    ? errorView.detail
+      ? `${errorView.title} — ${errorView.detail}`
+      : errorView.title
+    : stopNotice === "manual"
+      ? t("Response stopped.")
+      : stopNotice === "disconnect"
+        ? t("Connection lost — the answer was interrupted.")
+        : null;
+
+  // Mirror the live useChat snapshot into the parent-owned ref so the export
+  // (handled in AiChatWindow) can include the in-progress streaming turn AND the
+  // on-screen banner. The cleanup clears the ref on unmount so a thread torn down
+  // by `key` on chat switch can't leak its (possibly still-streaming) tail into
+  // the next chat's export before the new thread's effect repopulates the ref.
+  useEffect(() => {
+    if (!liveStateRef) return;
+    liveStateRef.current = { messages, isStreaming, banner };
+    return () => {
+      liveStateRef.current = { messages: [], isStreaming: false, banner: null };
+    };
+  }, [liveStateRef, messages, isStreaming, banner]);
+
+  // Reactively report "the live thread has content" to the parent. `liveStateRef`
+  // above is a ref (deliberately non-reactive so streaming deltas don't re-render
+  // the parent), so the export button needs a SEPARATE reactive signal to flip on
+  // for a not-yet-persisted chat. Keyed on the boolean only — identical values are
+  // a no-op setState in the parent, so this does not add per-delta re-renders.
+  const hasLiveContent = messages.length > 0;
+  useEffect(() => {
+    if (!onLiveContentChange) return;
+    onLiveContentChange(hasLiveContent);
+    return () => onLiveContentChange(false);
+  }, [onLiveContentChange, hasLiveContent]);
+
   // Report the live turn-token total to the parent header badge, THROTTLED to
   // ~8 Hz so the parent re-renders a few times a second instead of on every
   // streamed delta. The tail assistant message's reasoning+output (estimate while

apps/client/src/features/ai-chat/components/reasoning-block.tsx

@@ -3,6 +3,7 @@ import { Box, Collapse, Group, Text, UnstyledButton } from "@mantine/core";
 import { IconChevronDown } from "@tabler/icons-react";
 import { useTranslation } from "react-i18next";
 import { estimateTokens } from "@/features/ai-chat/utils/count-stream-tokens.ts";
+import { collapseBlankLines } from "@/features/ai-chat/utils/collapse-blank-lines.ts";
 import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
 import classes from "@/features/ai-chat/components/ai-chat.module.css";
 
@@ -33,7 +34,12 @@ export default function ReasoningBlock({ text, tokens }: ReasoningBlockProps) {
   // Authoritative count wins; otherwise estimate live from the streamed text.
   const count = tokens && tokens > 0 ? tokens : estimateTokens(text);
   const trimmed = text.trim();
-  const html = trimmed ? renderChatMarkdown(trimmed, {}) : "";
+  // Collapse the blank-line gaps the model emits between every list item /
+  // paragraph so the reasoning renders compactly (tight lists, joined
+  // paragraphs) — see collapseBlankLines. ONLY here, not in the normal answer.
+  const html = trimmed
+    ? renderChatMarkdown(collapseBlankLines(trimmed), {})
+    : "";
 
   return (
     <Box className={classes.reasoningBlock} mb={6}>

apps/client/src/features/ai-chat/hooks/use-chat-session.test.tsx

@@ -64,10 +64,7 @@ describe("useChatSession", () => {
     result.current.onTurnFinished(undefined);
     expect(setActiveChatId).not.toHaveBeenCalled();
     // The refetch lands with the new row => adopt it.
-    rerender({
-      activeChatId: null,
-      chats: { items: [{ id: "x" }, { id: "new" }] },
-    });
+    rerender({ activeChatId: null, chats: { items: [{ id: "x" }, { id: "new" }] } });
     expect(setActiveChatId).toHaveBeenCalledWith("new");
   });
 
@@ -91,10 +88,7 @@ describe("useChatSession", () => {
     });
     result.current.onTurnFinished(undefined);
     // a was deleted, new was added — same length, but membership changed.
-    rerender({
-      activeChatId: null,
-      chats: { items: [{ id: "b" }, { id: "new" }] },
-    });
+    rerender({ activeChatId: null, chats: { items: [{ id: "b" }, { id: "new" }] } });
     expect(setActiveChatId).toHaveBeenCalledWith("new");
   });
 
@@ -177,40 +171,6 @@ describe("useChatSession", () => {
     expect(setActiveChatId).not.toHaveBeenCalledWith("late");
   });
 
-  it("#174 early adopt: onServerChatId adopts the streamed id mid-stream (Copy button available during the first turn)", () => {
-    // Brand-new chat: no id yet. The server streams the real chat id "A" on the
-    // `start` chunk WHILE the first turn is still streaming (before onTurnFinished
-    // fires at the terminal outcome). The hook must adopt it immediately so the
-    // window's activeChatId-gated Copy/export button lights up during the stream.
-    const { result, setActiveChatId } = setup({
-      activeChatId: null,
-      chats: { items: [] },
-    });
-    result.current.onServerChatId("A");
-    expect(setActiveChatId).toHaveBeenCalledWith("A");
-  });
-
-  it("#174 early adopt is in-place: threadKey stays stable (live stream not torn down)", () => {
-    const chats = { items: [] };
-    const { result, rerender } = setup({ activeChatId: null, chats });
-    const keyBefore = result.current.threadKey;
-    result.current.onServerChatId("A");
-    // Parent reflects the adopted id back in; the SAME mount key is kept so the
-    // in-flight useChat store (the streaming turn) is preserved.
-    rerender({ activeChatId: "A", chats });
-    expect(result.current.threadKey).toBe(keyBefore);
-  });
-
-  it("#174 early adopt: no-op for an existing chat and for a missing id", () => {
-    const { result, setActiveChatId } = setup({
-      activeChatId: "chat-1",
-      chats: { items: [{ id: "chat-1" }] },
-    });
-    result.current.onServerChatId("chat-1"); // already has an id
-    result.current.onServerChatId(undefined); // no streamed id
-    expect(setActiveChatId).not.toHaveBeenCalled();
-  });
-
   it("in-place adopt keeps threadKey stable; an external switch remounts", () => {
     const chats = { items: [{ id: "B" }] };
     const { result, rerender } = setup({ activeChatId: null, chats });

apps/client/src/features/ai-chat/hooks/use-chat-session.ts

@@ -34,13 +34,6 @@ export interface UseChatSessionResult {
   /** Call when a turn finishes; `serverChatId` is the authoritative streamed id
    *  (undefined on a failed turn). Handles new-chat id adoption + invalidations. */
   onTurnFinished: (serverChatId?: string) => void;
-  /** Call EARLY (at the stream's `start` chunk) with the authoritative streamed
-   *  chat id so a brand-new chat adopts its real id WHILE its first turn is still
-   *  streaming — making `activeChatId`-gated affordances (e.g. the Copy/export
-   *  button, #174) available immediately. In-place adoption only (same mount key,
-   *  no list/messages invalidation — that is left to onTurnFinished at the end).
-   *  Idempotent and a no-op once the chat already has an id. */
-  onServerChatId: (serverChatId?: string) => void;
   /** Disarm any pending error-path new-chat fallback. The window calls this from
    *  startNewChat/selectChat so a late refetch can't yank the user back into a
    *  just-failed chat after they explicitly moved on. */
@@ -92,10 +85,13 @@ export function useChatSession(
   // `newThread`/`switchThread` to (re)mount, `adoptThread` for in-place adoption.
   // Initial: a non-null activeChatId switches to it; a null one gets a fresh
   // session key with no chat id yet.
-  const [thread, dispatch] = useReducer(threadSessionReducer, undefined, () =>
-    activeChatId === null
-      ? newThread(`new-${generateId()}`)
-      : switchThread(activeChatId),
+  const [thread, dispatch] = useReducer(
+    threadSessionReducer,
+    undefined,
+    () =>
+      activeChatId === null
+        ? newThread(`new-${generateId()}`)
+        : switchThread(activeChatId),
   );
 
   // Error-path fallback for new-chat id adoption. When a brand-new chat's first
@@ -154,31 +150,6 @@ export function useChatSession(
     [chats, setActiveChatId, onInvalidateChatList, onInvalidateChatMessages],
   );
 
-  // EARLY adoption (#174): adopt the authoritative streamed chat id the moment
-  // the server emits it on the `start` chunk, so a brand-new chat gets its real
-  // `activeChatId` WHILE its first turn streams — not only at terminal
-  // onTurnFinished. This makes the activeChatId-gated Copy/export button
-  // available during the first turn. Pure in-place adoption (same mount key, like
-  // the primary path) with NO invalidation: the list/messages refresh stays on
-  // onTurnFinished at the end of the turn. Reads the live id from the ref so a
-  // repeat call after adoption is a no-op (resolveAdoptedChatId only fires for a
-  // still-new chat).
-  const onServerChatId = useCallback(
-    (serverChatId?: string) => {
-      const adopted = resolveAdoptedChatId(
-        activeChatIdRef.current,
-        serverChatId,
-      );
-      if (!adopted) return;
-      activeChatIdRef.current = adopted;
-      setActiveChatId(adopted);
-      dispatch({ type: "adopt", chatId: adopted });
-      // Early adoption beat the error-path fallback to it — disarm.
-      pendingNewChatRef.current = null;
-    },
-    [setActiveChatId],
-  );
-
   // FALLBACK resolver. Armed only by onTurnFinished when a brand-new chat's first
   // turn errored before the `start` chunk (no authoritative id streamed). Once
   // the per-user list refetch lands with the just-created row, adopt the SINGLE
@@ -262,7 +233,6 @@ export function useChatSession(
     threadKey: thread.key,
     waitingForHistory,
     onTurnFinished,
-    onServerChatId,
     cancelPendingAdoption,
   };
 }

apps/client/src/features/ai-chat/services/ai-chat-service.ts

@@ -50,24 +50,6 @@ export async function deleteAiChat(chatId: string): Promise<void> {
   await api.post("/ai-chat/delete", { chatId });
 }
 
-/**
- * Export a chat to Markdown (#183). The server renders the transcript from the
- * persisted rows (the DB is the single source of truth — including an
- * interrupted turn's in-progress row, persisted upfront + per step), so the
- * client just copies the returned string. `lang` localizes the few fixed
- * role/tool labels; defaults to English server-side when omitted.
- */
-export async function exportAiChat(
-  chatId: string,
-  lang?: string,
-): Promise<string> {
-  const req = await api.post<{ markdown: string }>("/ai-chat/export", {
-    chatId,
-    lang,
-  });
-  return req.data.markdown;
-}
-
 /**
  * Agent roles API (`/ai-chat/roles`). `list` is available to any workspace
  * member (for the chat-creation picker); create/update/delete are admin-only
@@ -94,8 +76,6 @@ export async function updateAiRole(data: IAiRoleUpdate): Promise<IAiRole> {
 
 /** Soft-delete a role (admin). */
 export async function deleteAiRole(id: string): Promise<{ success: true }> {
-  const req = await api.post<{ success: true }>("/ai-chat/roles/delete", {
-    id,
-  });
+  const req = await api.post<{ success: true }>("/ai-chat/roles/delete", { id });
   return req.data;
 }

apps/client/src/features/ai-chat/utils/chat-markdown.test.ts

@@ -0,0 +1,747 @@
+import { describe, it, expect } from "vitest";
+import { buildChatMarkdown } from "@/features/ai-chat/utils/chat-markdown.ts";
+import type { IAiChatMessageRow } from "@/features/ai-chat/types/ai-chat.types.ts";
+
+/**
+ * Tests for the client-only Markdown export builder. The output embeds a live
+ * `new Date().toISOString()` export timestamp; we never assert that value, only
+ * the deterministic structure (headings, numbering, fenced blocks, totals).
+ *
+ * A pass-through translator keeps role/tool labels predictable so the
+ * structural assertions are stable without an i18n runtime.
+ */
+const t = (key: string, values?: Record<string, unknown>): string => {
+  if (values && typeof values.name === "string") {
+    return key.replace("{{name}}", values.name);
+  }
+  return key;
+};
+
+function row(partial: Partial<IAiChatMessageRow>): IAiChatMessageRow {
+  return {
+    id: partial.id ?? "id",
+    role: partial.role ?? "user",
+    content: partial.content ?? null,
+    metadata: partial.metadata ?? null,
+    createdAt: partial.createdAt ?? "2026-06-21T00:00:00.000Z",
+  };
+}
+
+describe("buildChatMarkdown — structure", () => {
+  it("emits the title heading, chat id and message count", () => {
+    const md = buildChatMarkdown({
+      title: "My chat",
+      chatId: "chat-123",
+      rows: [],
+      t,
+    });
+    expect(md).toContain("# My chat");
+    expect(md).toContain("- Chat ID: `chat-123`");
+    expect(md).toContain("- Messages: 0");
+    expect(md).toContain("- Exported:"); // timestamp present, value not asserted
+  });
+
+  it("falls back to the translated 'Untitled chat' for empty/blank titles", () => {
+    expect(
+      buildChatMarkdown({ title: null, chatId: "c", rows: [], t }),
+    ).toContain("# Untitled chat");
+    expect(
+      buildChatMarkdown({ title: "   ", chatId: "c", rows: [], t }),
+    ).toContain("# Untitled chat");
+  });
+
+  it("numbers rows sequentially with role headings", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({ role: "user", content: "hi" }),
+        row({ role: "assistant", content: "hello" }),
+        row({ role: "user", content: "again" }),
+      ],
+      t,
+    });
+    expect(md).toContain("## 1. You");
+    expect(md).toContain("## 2. AI agent");
+    expect(md).toContain("## 3. You");
+    // Heading numbering is strictly index+1, not e.g. role-relative.
+    expect(md).not.toContain("## 0.");
+  });
+
+  it("renders the per-row text content from `content` when no metadata.parts", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ role: "user", content: "plain body" })],
+      t,
+    });
+    expect(md).toContain("plain body");
+  });
+});
+
+describe("buildChatMarkdown — text parts", () => {
+  it("skips empty / whitespace-only text parts", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "ignored-content",
+          metadata: {
+            parts: [
+              { type: "text", text: "   " },
+              { type: "text", text: "" },
+              { type: "text", text: "kept line" },
+              // eslint-disable-next-line @typescript-eslint/no-explicit-any
+            ] as any,
+          },
+        }),
+      ],
+      t,
+    });
+    expect(md).toContain("kept line");
+    // Whitespace-only part contributed no block of its own.
+    expect(md).not.toContain("   \n\n");
+    // When metadata.parts exists, the plain `content` fallback is NOT used.
+    expect(md).not.toContain("ignored-content");
+  });
+});
+
+describe("buildChatMarkdown — tool parts", () => {
+  it("renders a tool label, name, state and fenced Input/Output blocks", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "",
+          metadata: {
+            parts: [
+              {
+                type: "tool-getPage",
+                state: "output-available",
+                input: { pageId: "p1" },
+                output: { id: "p1", title: "Home" },
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+              } as any,
+            ],
+          },
+        }),
+      ],
+      t,
+    });
+    // Known tool name maps to its label key; raw name in backticks; done state.
+    expect(md).toContain("**Tool: Read page** (`getPage`) — done");
+    expect(md).toContain("Input:");
+    expect(md).toContain("Output:");
+    // Fenced JSON blocks contain the stringified payloads.
+    expect(md).toContain('"pageId": "p1"');
+    expect(md).toContain('"title": "Home"');
+    expect(md).toContain("```json");
+  });
+
+  it("renders the generic label for an unknown tool and surfaces errorText", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "",
+          metadata: {
+            parts: [
+              {
+                type: "tool-mysteryTool",
+                state: "output-error",
+                input: { a: 1 },
+                errorText: "boom",
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+              } as any,
+            ],
+          },
+        }),
+      ],
+      t,
+    });
+    expect(md).toContain(
+      "**Tool: Ran tool mysteryTool** (`mysteryTool`) — error",
+    );
+    expect(md).toContain("**Error:** boom");
+  });
+
+  it("does not throw on a circular tool input (falls back to String)", () => {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const circular: any = {};
+    circular.self = circular;
+    expect(() =>
+      buildChatMarkdown({
+        title: "t",
+        chatId: "c",
+        rows: [
+          row({
+            role: "assistant",
+            content: "",
+            metadata: {
+              parts: [
+                {
+                  type: "tool-getPage",
+                  state: "input-available",
+                  input: circular,
+                  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                } as any,
+              ],
+            },
+          }),
+        ],
+        t,
+      }),
+    ).not.toThrow();
+  });
+});
+
+describe("buildChatMarkdown — fence anti-breakout", () => {
+  it("lengthens the delimiter so embedded ``` cannot break out of the block", () => {
+    // Tool input whose stringified string form contains a literal ``` run.
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "",
+          metadata: {
+            parts: [
+              {
+                type: "tool-getPage",
+                state: "output-available",
+                // A bare string passes through stringify() verbatim.
+                input: "before ``` after",
+                output: "x",
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+              } as any,
+            ],
+          },
+        }),
+      ],
+      t,
+    });
+    // The fence around the 3-backtick content must use at least 4 backticks so
+    // the embedded ``` run cannot terminate the block.
+    expect(md).toContain("````json\nbefore ``` after\n````");
+    // Robust anti-breakout check: the opening fence delimiter is strictly
+    // longer than the longest backtick run inside the wrapped content. (A naive
+    // `not.toContain("```json...")` is a false negative — a 4-backtick fence
+    // textually contains the 3-backtick substring.)
+    const open = md.match(/(`{3,})json\nbefore/);
+    expect(open).not.toBeNull();
+    expect(open![1].length).toBeGreaterThan(3); // > the 3-backtick run in content
+  });
+
+  it("uses a 5-backtick fence when the content has a 4-backtick run", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "",
+          metadata: {
+            parts: [
+              {
+                type: "tool-getPage",
+                state: "output-available",
+                input: "a ```` b",
+                // eslint-disable-next-line @typescript-eslint/no-explicit-any
+              } as any,
+            ],
+          },
+        }),
+      ],
+      t,
+    });
+    expect(md).toContain("`````json\na ```` b\n`````");
+  });
+});
+
+describe("buildChatMarkdown — token totals", () => {
+  it("prints the total-tokens line only when the summed usage is > 0", () => {
+    const withTokens = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: { usage: { inputTokens: 10, outputTokens: 5 } },
+        }),
+      ],
+      t,
+    });
+    expect(withTokens).toContain("- Total tokens: 15");
+    // Per-row usage footer too.
+    expect(withTokens).toContain("_Tokens — in: 10, out: 5, total: 15_");
+  });
+
+  it("omits the total-tokens line when the sum is 0 / usage absent", () => {
+    const noTokens = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({ role: "user", content: "hi" }),
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: { usage: { inputTokens: 0, outputTokens: 0 } },
+        }),
+      ],
+      t,
+    });
+    expect(noTokens).not.toContain("- Total tokens:");
+  });
+
+  it("uses totalTokens when present rather than summing in/out", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: {
+            usage: { inputTokens: 3, outputTokens: 4, totalTokens: 99 },
+          },
+        }),
+      ],
+      t,
+    });
+    expect(md).toContain("- Total tokens: 99");
+  });
+
+  it("appends the reasoning figure to the row footer when reasoningTokens > 0", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: {
+            usage: { inputTokens: 10, outputTokens: 8, reasoningTokens: 3 },
+          },
+        }),
+      ],
+      t,
+    });
+    expect(md).toContain("_Tokens — in: 10, out: 8, reasoning: 3, total: 18_");
+  });
+
+  it("omits the reasoning figure when reasoningTokens is 0 / absent", () => {
+    const zero = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: {
+            usage: { inputTokens: 10, outputTokens: 5, reasoningTokens: 0 },
+          },
+        }),
+      ],
+      t,
+    });
+    expect(zero).toContain("_Tokens — in: 10, out: 5, total: 15_");
+    expect(zero).not.toContain("reasoning:");
+
+    const absent = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          role: "assistant",
+          content: "x",
+          metadata: { usage: { inputTokens: 10, outputTokens: 5 } },
+        }),
+      ],
+      t,
+    });
+    expect(absent).not.toContain("reasoning:");
+  });
+});
+
+// A minimal on-screen (live) message, matching the subset buildChatMarkdown reads.
+function live(partial: {
+  id?: string;
+  role?: string;
+  parts?: { type: string; text?: string }[];
+  metadata?: { usage?: Record<string, number>; error?: string };
+}) {
+  return {
+    id: partial.id ?? "live-id",
+    role: partial.role ?? "assistant",
+    parts: partial.parts ?? [],
+    metadata: partial.metadata,
+  };
+}
+
+describe("buildChatMarkdown — live (WYSIWYG) source", () => {
+  it("uses the live messages as the document (what's on screen), numbered from 1", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      // Persisted rows hold only the user turn; the assistant reply is live-only.
+      rows: [row({ id: "u1", role: "user", content: "persisted user" })],
+      live: [
+        live({
+          id: "u1",
+          role: "user",
+          parts: [{ type: "text", text: "on-screen user" }],
+        }),
+        live({
+          id: "a1",
+          role: "assistant",
+          parts: [{ type: "text", text: "on-screen reply" }],
+        }),
+      ],
+      isStreaming: false,
+      t,
+    });
+    expect(md).toContain("## 1. You");
+    expect(md).toContain("## 2. AI agent");
+    expect(md).toContain("on-screen user");
+    expect(md).toContain("on-screen reply");
+    // Message count reflects the LIVE document, not rows + live.
+    expect(md).toContain("- Messages: 2");
+  });
+
+  it("captures a partial reply from an interrupted (non-streaming) turn — no 'generating' note", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ id: "u1", role: "user", content: "q" })],
+      live: [
+        live({ id: "u1", role: "user", parts: [{ type: "text", text: "q" }] }),
+        live({
+          id: "a-live",
+          role: "assistant",
+          parts: [{ type: "text", text: "partial plan before the drop" }],
+        }),
+      ],
+      isStreaming: false, // the stream dropped — not streaming anymore
+      banner: "Connection lost — the answer was interrupted.",
+      t,
+    });
+    // The partial assistant answer that was on screen IS in the export.
+    expect(md).toContain("partial plan before the drop");
+    // It is NOT flagged still-generating (the turn is over, just interrupted).
+    expect(md).not.toContain("still being generated");
+    // The on-screen banner is recorded at the end.
+    expect(md).toContain("Connection lost — the answer was interrupted.");
+  });
+
+  it("flags ONLY the tail assistant as still generating, and only while streaming", () => {
+    const streaming = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [],
+      live: [
+        live({
+          id: "a",
+          role: "assistant",
+          parts: [{ type: "text", text: "done earlier" }],
+        }),
+        live({
+          id: "u",
+          role: "user",
+          parts: [{ type: "text", text: "next q" }],
+        }),
+        live({
+          id: "b",
+          role: "assistant",
+          parts: [{ type: "text", text: "streaming now" }],
+        }),
+      ],
+      isStreaming: true,
+      t,
+    });
+    // Exactly one "still being generated" note (the tail assistant).
+    expect(streaming.match(/still being generated/g)?.length).toBe(1);
+
+    const idle = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [],
+      live: [
+        live({
+          id: "b",
+          role: "assistant",
+          parts: [{ type: "text", text: "final" }],
+        }),
+      ],
+      isStreaming: false,
+      t,
+    });
+    expect(idle).not.toContain("still being generated");
+  });
+
+  it("does NOT flag a completed assistant as generating when the streaming tail is a user message", () => {
+    // The `status === "submitted"` window: the user just sent, isStreaming is
+    // already true, but the new assistant turn has no message yet so the tail is
+    // the USER message. The previous assistant answer is complete on screen and
+    // must not be marked still-generating (WYSIWYG; regression for #160 review).
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [],
+      live: [
+        live({
+          id: "a",
+          role: "assistant",
+          parts: [{ type: "text", text: "completed answer" }],
+        }),
+        live({
+          id: "u",
+          role: "user",
+          parts: [{ type: "text", text: "the new question" }],
+        }),
+      ],
+      isStreaming: true,
+      t,
+    });
+    expect(md).toContain("completed answer");
+    expect(md).not.toContain("still being generated");
+  });
+
+  it("emits the heading + note for a streaming tail assistant with empty parts", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ id: "u1", role: "user", content: "q" })],
+      live: [
+        live({ id: "u1", role: "user", parts: [{ type: "text", text: "q" }] }),
+        live({ id: "a-live", role: "assistant", parts: [] }),
+      ],
+      isStreaming: true,
+      t,
+    });
+    expect(md).toContain("## 2. AI agent");
+    expect(md).toContain("still being generated");
+  });
+});
+
+describe("buildChatMarkdown — live enrichment from persisted rows", () => {
+  it("pulls usage / error / timestamp from the persisted row matched by id", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          id: "a1",
+          role: "assistant",
+          content: "x",
+          createdAt: "2026-06-22T10:00:00.000Z",
+          metadata: {
+            usage: { inputTokens: 10, outputTokens: 5 },
+            error: "rate limited",
+          },
+        }),
+      ],
+      live: [
+        // Same id as the persisted row, but no usage/error/timestamp on the live msg.
+        live({
+          id: "a1",
+          role: "assistant",
+          parts: [{ type: "text", text: "reply" }],
+        }),
+      ],
+      isStreaming: false,
+      t,
+    });
+    expect(md).toContain("reply");
+    // Token footer + total come from the enriched row.
+    expect(md).toContain("_Tokens — in: 10, out: 5, total: 15_");
+    expect(md).toContain("- Total tokens: 15");
+    expect(md).toContain("**⚠️ Error:** rate limited");
+    // The persisted timestamp is carried into the export.
+    expect(md).toContain("<!-- 2026-06-22T10:00:00.000Z -->");
+  });
+
+  it("prefers authoritative usage already on the live message over the row's", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({
+          id: "a1",
+          role: "assistant",
+          content: "x",
+          metadata: {
+            usage: { inputTokens: 1, outputTokens: 1, totalTokens: 2 },
+          },
+        }),
+      ],
+      live: [
+        live({
+          id: "a1",
+          role: "assistant",
+          parts: [{ type: "text", text: "reply" }],
+          metadata: {
+            usage: { inputTokens: 100, outputTokens: 50, totalTokens: 150 },
+          },
+        }),
+      ],
+      isStreaming: false,
+      t,
+    });
+    // The live (authoritative, freshest) usage wins, not the stale row usage.
+    expect(md).toContain("- Total tokens: 150");
+    expect(md).not.toContain("- Total tokens: 2");
+  });
+
+  it("a current-turn live message with no matching row renders without a footer", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ id: "u1", role: "user", content: "q" })],
+      live: [
+        live({ id: "u1", role: "user", parts: [{ type: "text", text: "q" }] }),
+        live({
+          id: "a-live",
+          role: "assistant",
+          parts: [{ type: "text", text: "fresh reply" }],
+        }),
+      ],
+      isStreaming: false,
+      t,
+    });
+    expect(md).toContain("fresh reply");
+    // No persisted row for the live assistant -> no token footer, no timestamp.
+    expect(md).not.toContain("_Tokens —");
+    expect(md).not.toContain("<!-- undefined -->");
+  });
+});
+
+describe("buildChatMarkdown — fallback + banner", () => {
+  it("falls back to the persisted rows when there are no live messages", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [
+        row({ role: "user", content: "from rows" }),
+        row({
+          role: "assistant",
+          content: "answer",
+          metadata: { usage: { inputTokens: 4, outputTokens: 6 } },
+        }),
+      ],
+      live: [], // empty live mirror -> fallback path
+      isStreaming: false,
+      t,
+    });
+    expect(md).toContain("## 1. You");
+    expect(md).toContain("## 2. AI agent");
+    expect(md).toContain("from rows");
+    expect(md).toContain("- Messages: 2");
+    expect(md).toContain("- Total tokens: 10");
+  });
+
+  it("appends the on-screen banner once, after the messages", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ role: "user", content: "q" })],
+      live: [
+        live({ id: "u", role: "user", parts: [{ type: "text", text: "q" }] }),
+      ],
+      isStreaming: false,
+      banner: "Rate limit reached — try again shortly.",
+      t,
+    });
+    expect(md).toContain("_⚠️ Rate limit reached — try again shortly._");
+    // Banner comes after the (only) message block.
+    expect(md.indexOf("Rate limit reached")).toBeGreaterThan(
+      md.indexOf("## 1."),
+    );
+  });
+
+  it("omits the banner block when there is no banner", () => {
+    const md = buildChatMarkdown({
+      title: "t",
+      chatId: "c",
+      rows: [row({ role: "user", content: "q" })],
+      live: [
+        live({ id: "u", role: "user", parts: [{ type: "text", text: "q" }] }),
+      ],
+      isStreaming: false,
+      banner: null,
+      t,
+    });
+    expect(md).not.toContain("_⚠️");
+  });
+});
+
+// #174: a brand-new, not-yet-persisted chat whose first turn is streaming (or was
+// interrupted) has live messages but NO persisted rows yet, and its chat id is not
+// known (the caller passes a placeholder). The export must still capture the
+// on-screen thread WYSIWYG from the live messages alone.
+describe("buildChatMarkdown — first-turn export with no persisted base (#174)", () => {
+  it("builds the document from live messages alone when rows are empty", () => {
+    const md = buildChatMarkdown({
+      title: null,
+      chatId: "unsaved",
+      rows: [],
+      live: [
+        live({
+          id: "u1",
+          role: "user",
+          parts: [{ type: "text", text: "hello" }],
+        }),
+        live({
+          id: "a1",
+          role: "assistant",
+          parts: [{ type: "text", text: "partial reply" }],
+        }),
+      ],
+      isStreaming: true,
+      t,
+    });
+    // Both on-screen messages are serialized, numbered from 1.
+    expect(md).toContain("## 1. You");
+    expect(md).toContain("hello");
+    expect(md).toContain("## 2. AI agent");
+    expect(md).toContain("partial reply");
+    // The streaming tail assistant is flagged as in-progress.
+    expect(md).toContain("still being generated");
+    // The placeholder chat id and the live message count are recorded.
+    expect(md).toContain("- Chat ID: `unsaved`");
+    expect(md).toContain("- Messages: 2");
+    // No persisted timestamp exists for a current-turn live message.
+    expect(md).not.toContain("<!--");
+  });
+
+  it("captures an interrupted first turn (no rows, not streaming) without a generating note", () => {
+    const md = buildChatMarkdown({
+      title: null,
+      chatId: "unsaved",
+      rows: [],
+      live: [
+        live({ id: "u1", role: "user", parts: [{ type: "text", text: "q" }] }),
+        live({
+          id: "a1",
+          role: "assistant",
+          parts: [{ type: "text", text: "half an answer" }],
+        }),
+      ],
+      isStreaming: false,
+      banner: "Connection dropped — the response was cut off.",
+      t,
+    });
+    expect(md).toContain("half an answer");
+    // An interrupted (non-streaming) partial is exported as-is, no generating note.
+    expect(md).not.toContain("still being generated");
+    // The on-screen banner records the interruption.
+    expect(md).toContain("_⚠️ Connection dropped — the response was cut off._");
+  });
+});

apps/client/src/features/ai-chat/utils/chat-markdown.ts

@@ -0,0 +1,308 @@
+/**
+ * Client-only Markdown builder for an AI agent chat. Serializes the already
+ * persisted message rows (loaded via `useAiChatMessagesQuery`) into a single
+ * Markdown string suitable for copying to the clipboard. NO network call is
+ * made and NO server/DB code is touched — this reuses the rich "request
+ * internals" (tool calls with input/output, per-message token usage,
+ * finish/error info) that the chat already holds client-side.
+ *
+ * Only role labels and tool action labels are localized via the passed-in `t`
+ * translator; the structural document words (Input/Output/Error/Tokens/...) are
+ * plain English constants because the output is a technical artifact.
+ */
+
+import type { IAiChatMessageRow } from "@/features/ai-chat/types/ai-chat.types.ts";
+import {
+  ToolUiPart,
+  getToolName,
+  toolRunState,
+  toolLabelKey,
+} from "@/features/ai-chat/utils/tool-parts.tsx";
+
+// Minimal translator signature compatible with react-i18next's `t`.
+type Translate = (key: string, values?: Record<string, unknown>) => string;
+
+interface BuildChatMarkdownArgs {
+  title: string | null;
+  chatId: string;
+  /** The live, on-screen messages — the WYSIWYG source of the export. When
+   *  present and non-empty these DRIVE the document (so it mirrors exactly what
+   *  the user sees, including a partial reply from an interrupted turn). Each is
+   *  matched to a persisted row by `id` to enrich it with token usage / error /
+   *  timestamp. When absent or empty the builder falls back to `rows`. */
+  live?: LiveMessage[];
+  /** Persisted message rows. Enrichment source (matched to `live` by id) AND the
+   *  fallback document source when `live` is empty. */
+  rows: IAiChatMessageRow[];
+  /** Whether the live thread is still streaming. Only then is the tail assistant
+   *  message flagged "still generating"; an interrupted (non-streaming) partial
+   *  reply is exported as-is and the `banner` explains the interruption. */
+  isStreaming?: boolean;
+  /** The on-screen banner text (error / dropped connection / manual stop),
+   *  appended at the end of the export so the artifact records the interruption
+   *  the user saw. */
+  banner?: string | null;
+  t: Translate;
+}
+
+/** A single AI SDK UIMessage part (text part or other). */
+interface TextLikePart {
+  type: string;
+  text?: string;
+}
+
+/** Authoritative per-turn usage the server attaches to a message / row. */
+interface UsageLike {
+  inputTokens?: number;
+  outputTokens?: number;
+  totalTokens?: number;
+  reasoningTokens?: number;
+}
+
+/** A live, on-screen message (subset of the AI SDK UIMessage we consume). */
+interface LiveMessage {
+  id: string;
+  role: "user" | "assistant" | string;
+  parts: TextLikePart[];
+  metadata?: { usage?: UsageLike; error?: string };
+}
+
+/** One message normalized for rendering, regardless of live/persisted origin. */
+interface ExportItem {
+  role: string;
+  parts: TextLikePart[];
+  usage?: UsageLike;
+  error?: string;
+  /** ISO timestamp from the persisted row, when one is known. */
+  createdAt?: string;
+  /** True only for the tail assistant message while the thread is streaming. */
+  generating: boolean;
+}
+
+/**
+ * Stringify an arbitrary tool input/output value for a fenced block. Strings
+ * pass through as-is; everything else is pretty-printed JSON, falling back to
+ * `String(value)` if serialization throws (e.g. a circular structure).
+ */
+function stringify(value: unknown): string {
+  if (typeof value === "string") return value;
+  try {
+    return JSON.stringify(value, null, 2);
+  } catch {
+    return String(value);
+  }
+}
+
+/**
+ * Wrap `code` in a fenced code block whose backtick delimiter is LONGER than
+ * the longest backtick run inside the content, so embedded backticks (or even
+ * a literal ``` fence) never break out of the block. Minimum 3 backticks.
+ */
+function fence(code: string, lang = ""): string {
+  const runs: string[] = code.match(/`+/g) ?? [];
+  const longest = runs.reduce((m, s) => Math.max(m, s.length), 0);
+  const delim = "`".repeat(Math.max(3, longest + 1));
+  return `${delim}${lang}\n${code}\n${delim}`;
+}
+
+/** Per-row token count, mirroring the header sum in ai-chat-window.tsx. */
+function rowTokens(usage: {
+  inputTokens?: number;
+  outputTokens?: number;
+  totalTokens?: number;
+  reasoningTokens?: number;
+}): number {
+  return (
+    usage.totalTokens ?? (usage.inputTokens ?? 0) + (usage.outputTokens ?? 0)
+  );
+}
+
+/** Render one message's UIMessage parts into an array of Markdown blocks
+ *  (text blocks + tool blocks). Mirrors MessageItem's part handling. */
+function renderMessageParts(parts: TextLikePart[], t: Translate): string[] {
+  const out: string[] = [];
+
+  for (const part of parts) {
+    if (part.type === "text") {
+      const text = (part.text ?? "").trim();
+      // Skip empty/whitespace-only text parts (matches MessageItem).
+      if (text.length > 0) out.push(text);
+      continue;
+    }
+
+    const isToolPart =
+      part.type.startsWith("tool-") || part.type === "dynamic-tool";
+    if (!isToolPart) continue;
+
+    const tp = part as unknown as ToolUiPart;
+    const name = getToolName(tp);
+    const { key, values } = toolLabelKey(name);
+    const label = t(key, values);
+    const state = toolRunState(tp.state);
+
+    const toolLines: string[] = [
+      `**Tool: ${label}** (\`${name}\`) — ${state}`,
+    ];
+    if (tp.input !== undefined) {
+      toolLines.push("Input:");
+      toolLines.push(fence(stringify(tp.input), "json"));
+    }
+    if (tp.output !== undefined) {
+      toolLines.push("Output:");
+      toolLines.push(fence(stringify(tp.output), "json"));
+    }
+    if (tp.errorText) {
+      toolLines.push(`**Error:** ${tp.errorText}`);
+    }
+    out.push(toolLines.join("\n\n"));
+  }
+
+  return out;
+}
+
+/** Resolve a persisted row's parts: prefer the rich persisted parts, else a
+ *  single text part built from the plain-text content (mirrors `rowToUiMessage`). */
+function rowParts(row: IAiChatMessageRow): TextLikePart[] {
+  return Array.isArray(row.metadata?.parts) && row.metadata.parts.length > 0
+    ? (row.metadata.parts as TextLikePart[])
+    : [{ type: "text", text: row.content ?? "" }];
+}
+
+/**
+ * Normalize the export to one ordered list of {@link ExportItem}, WYSIWYG-first:
+ *
+ * - When `live` messages are present, THEY are the document (what the user sees,
+ *   incl. an interrupted turn's partial reply). Each is matched to a persisted
+ *   row by `id` to pull token usage / error / timestamp — a live message of the
+ *   CURRENT turn has no matching row yet, so it simply renders without a footer.
+ *   Authoritative `usage`/`error` already on the live message metadata win over
+ *   the row (the server attaches usage to the streamed message at a step
+ *   boundary before the row is refetched). Only the tail assistant message is
+ *   flagged `generating`, and only while `isStreaming`.
+ * - When `live` is empty (e.g. the export runs before the live mirror is
+ *   populated), fall back to the persisted `rows` so the format never regresses.
+ */
+function resolveItems(
+  live: LiveMessage[] | undefined,
+  rows: IAiChatMessageRow[],
+  isStreaming: boolean,
+): ExportItem[] {
+  if (live && live.length > 0) {
+    const rowsById = new Map(rows.map((r) => [r.id, r]));
+    // The "still generating" note may apply ONLY to an assistant message that is
+    // the actual TAIL of the list — that is where the on-screen typing indicator
+    // sits. While `status === "submitted"` (isStreaming true) right after the
+    // user hit send, the tail is the USER message and the new assistant turn has
+    // no message yet; the previous assistant answer is shown complete on screen,
+    // so it must NOT be flagged (the indicator renders as a separate bottom
+    // block, not on that answer).
+    const lastIndex = live.length - 1;
+    const tailIsStreamingAssistant =
+      isStreaming && live[lastIndex]?.role === "assistant";
+    return live.map((m, i) => {
+      const row = rowsById.get(m.id);
+      return {
+        role: m.role,
+        parts: m.parts ?? [],
+        // Authoritative usage/error already on the live message (the server
+        // attaches usage to the streamed message at a step boundary) wins over
+        // the persisted row; a current-turn live message has no matching row yet
+        // and simply renders without a token footer (the accepted WYSIWYG
+        // tradeoff — an interrupted turn loses only its token footer, not text).
+        usage: m.metadata?.usage ?? row?.metadata?.usage,
+        error: m.metadata?.error ?? row?.metadata?.error ?? undefined,
+        createdAt: row?.createdAt,
+        generating: tailIsStreamingAssistant && i === lastIndex,
+      };
+    });
+  }
+
+  return rows.map((row) => ({
+    role: row.role,
+    parts: rowParts(row),
+    usage: row.metadata?.usage,
+    error: row.metadata?.error ?? undefined,
+    createdAt: row.createdAt,
+    generating: false,
+  }));
+}
+
+/**
+ * Serialize a chat to a Markdown string. Pure (apart from `new Date()` for the
+ * export timestamp), so it is straightforward to unit-test.
+ */
+export function buildChatMarkdown(args: BuildChatMarkdownArgs): string {
+  const { title, chatId, live, rows, isStreaming, banner, t } = args;
+  const blocks: string[] = [];
+
+  const items = resolveItems(live, rows, isStreaming === true);
+
+  const heading = (title ?? "").trim() || t("Untitled chat");
+  blocks.push(`# ${heading}`);
+
+  // Metadata bullet list. Total tokens is only shown when there is a sum.
+  const totalTokens = items.reduce(
+    (sum, item) => (item.usage ? sum + rowTokens(item.usage) : sum),
+    0,
+  );
+  const meta = [
+    `- Chat ID: \`${chatId}\``,
+    `- Exported: ${new Date().toISOString()}`,
+    `- Messages: ${items.length}`,
+  ];
+  if (totalTokens > 0) meta.push(`- Total tokens: ${totalTokens}`);
+  blocks.push(meta.join("\n"));
+
+  items.forEach((item, index) => {
+    blocks.push("---");
+
+    const roleLabel = item.role === "assistant" ? t("AI agent") : t("You");
+    blocks.push(`## ${index + 1}. ${roleLabel}`);
+
+    // Created-at kept in source as an HTML comment (out of the rendered prose).
+    // A live message of the current turn has no persisted row yet — omit it.
+    if (item.createdAt) blocks.push(`<!-- ${item.createdAt} -->`);
+
+    blocks.push(...renderMessageParts(item.parts, t));
+
+    // A generating assistant may have empty/no parts yet — the heading (above)
+    // and this note still record the in-progress turn.
+    if (item.generating) {
+      blocks.push(
+        "_⏳ This message is still being generated — the export captured a partial, in-progress response._",
+      );
+    }
+
+    // A persisted per-message error (the raw provider text) may coexist with the
+    // trailing `banner` (the classified on-screen alert) when the failed turn's
+    // row has already been refetched by export time. They describe the same
+    // failure at different fidelity; showing both is an accepted, minor redundancy.
+    if (item.error) {
+      blocks.push(`**⚠️ Error:** ${item.error}`);
+    }
+
+    const usage = item.usage;
+    if (usage) {
+      const total = usage.totalTokens ?? rowTokens(usage);
+      // Reasoning (thinking) tokens are shown only when the provider reported a
+      // positive count; old rows / non-reasoning providers omit it.
+      const reasoning =
+        usage.reasoningTokens && usage.reasoningTokens > 0
+          ? `, reasoning: ${usage.reasoningTokens}`
+          : "";
+      blocks.push(
+        `_Tokens — in: ${usage.inputTokens ?? "?"}, out: ${usage.outputTokens ?? "?"}${reasoning}, total: ${total}_`,
+      );
+    }
+  });
+
+  // Record the on-screen banner (error / dropped connection / manual stop) so
+  // the export reflects exactly what the user saw, including an interruption.
+  if (banner && banner.trim().length > 0) {
+    blocks.push("---");
+    blocks.push(`_⚠️ ${banner.trim()}_`);
+  }
+
+  // Blank line between blocks so the Markdown renders cleanly.
+  return blocks.join("\n\n");
+}

apps/client/src/features/ai-chat/utils/collapse-blank-lines.test.ts

@@ -0,0 +1,61 @@
+import { describe, it, expect } from "vitest";
+import { collapseBlankLines } from "@/features/ai-chat/utils/collapse-blank-lines.ts";
+import { renderChatMarkdown } from "@/features/ai-chat/utils/markdown.ts";
+
+describe("collapseBlankLines", () => {
+  it("collapses a run of 2+ newlines to a single newline", () => {
+    expect(collapseBlankLines("a\n\nb")).toBe("a\nb");
+    expect(collapseBlankLines("a\n\n\n\nb")).toBe("a\nb");
+  });
+
+  it("keeps single newlines untouched", () => {
+    expect(collapseBlankLines("a\nb\nc")).toBe("a\nb\nc");
+  });
+
+  it("preserves blank lines INSIDE a fenced code block", () => {
+    const src = "a\n\n\nb\n\n```\nx\n\n\ny\n```\n\nc";
+    // Prose blanks collapse; the blank lines between the ``` fences survive.
+    expect(collapseBlankLines(src)).toBe("a\nb\n```\nx\n\n\ny\n```\nc");
+  });
+
+  it("handles a tilde fence and preserves its interior blanks", () => {
+    const src = "p\n\n~~~\ncode\n\nmore\n~~~\n\nq";
+    expect(collapseBlankLines(src)).toBe("p\n~~~\ncode\n\nmore\n~~~\nq");
+  });
+
+  it("leaves an unclosed fence's remaining lines verbatim", () => {
+    const src = "intro\n\n```\nstill\n\nopen";
+    expect(collapseBlankLines(src)).toBe("intro\n```\nstill\n\nopen");
+  });
+
+  it("is a no-op for text with no blank lines", () => {
+    expect(collapseBlankLines("just one line")).toBe("just one line");
+  });
+});
+
+describe("collapseBlankLines + renderChatMarkdown (tight reasoning rendering)", () => {
+  it("renders a blank-line-separated list as a TIGHT list (no <li><p>)", () => {
+    const loose =
+      "Intro paragraph.\n\n- item one\n\n- item two\n\n- item three";
+    const html = renderChatMarkdown(collapseBlankLines(loose), {});
+    // Tight list: each <li> holds the text directly, not wrapped in a <p>.
+    expect(html).toContain("<li>item one</li>");
+    expect(html).not.toContain("<li><p>");
+    // The list still parses as a list after the paragraph (not a paragraph+<br>).
+    expect(html).toContain("<ul>");
+    expect(html).toContain("<p>Intro paragraph.</p>");
+  });
+
+  it("renders an ordered list (1. 2.) as tight after collapsing", () => {
+    const loose = "Intro.\n\n1. first\n\n2. second";
+    const html = renderChatMarkdown(collapseBlankLines(loose), {});
+    expect(html).toContain("<ol>");
+    expect(html).toContain("<li>first</li>");
+    expect(html).not.toContain("<li><p>");
+  });
+
+  it("the loose source WOULD render <li><p> without collapsing (control)", () => {
+    const loose = "- a\n\n- b";
+    expect(renderChatMarkdown(loose, {})).toContain("<li><p>");
+  });
+});

apps/client/src/features/ai-chat/utils/collapse-blank-lines.ts

@@ -0,0 +1,56 @@
+// Pure helper for compact reasoning ("Thinking") rendering. Kept free of React
+// so it can be unit-tested in isolation (see collapse-blank-lines.test.ts).
+
+/**
+ * Collapse runs of 2+ newlines down to a single newline, EXCEPT inside fenced
+ * code blocks (``` ... ``` or ~~~ ... ~~~), where blank lines are significant.
+ *
+ * Why: reasoning models emit thinking with a blank line (`\n\n`) between every
+ * list item and paragraph. `marked` turns those into "loose" lists (each `<li>`
+ * wrapped in a `<p>`) and separate `<p>` paragraphs, each carrying a vertical
+ * margin — so the "Thinking" block renders with large, airy gaps. Removing the
+ * blank-line gaps yields tight lists (no `<li><p>`) and joined paragraphs. The
+ * chat markdown renderer runs with `breaks: true`, so a single `\n` still
+ * becomes a `<br>` — line breaks inside the reasoning are preserved; only the
+ * empty gaps between blocks disappear. Apply ONLY to reasoning text, never to a
+ * normal assistant answer (where paragraph spacing is intentional).
+ *
+ * Fenced code is preserved verbatim: a fence opens on a line whose first
+ * non-space characters are ``` or ~~~ and closes on the next line that starts
+ * with the same fence character. Blank lines between fences (significant for
+ * code formatting) are never collapsed.
+ */
+export function collapseBlankLines(text: string): string {
+  const lines = text.split("\n");
+  const out: string[] = [];
+  let inFence = false;
+  let fenceChar = "";
+
+  for (const line of lines) {
+    const fenceMatch = line.match(/^\s*(`{3,}|~{3,})/);
+    if (fenceMatch) {
+      const ch = fenceMatch[1][0];
+      if (!inFence) {
+        inFence = true;
+        fenceChar = ch;
+      } else if (ch === fenceChar) {
+        inFence = false;
+      }
+      out.push(line);
+      continue;
+    }
+
+    // Inside a fenced block every line (including blanks) is significant.
+    if (inFence) {
+      out.push(line);
+      continue;
+    }
+
+    // Outside fences: drop blank lines so a `\n\n+` gap collapses to a single
+    // `\n` between the surrounding content lines.
+    if (line.trim() === "") continue;
+    out.push(line);
+  }
+
+  return out.join("\n");
+}

apps/client/src/features/ai-chat/utils/count-stream-tokens.test.ts

@@ -117,3 +117,55 @@ describe("liveTurnTokens — authoritative path", () => {
     expect(r).toEqual({ reasoning: 0, output: 1, authoritative: false });
   });
 });
+
+describe("liveTurnTokens — combined authoritative + estimate (#163)", () => {
+  it("ticks the in-flight step above the completed-steps authoritative base", () => {
+    // The authoritative usage is the sum over COMPLETED steps (step 1). The
+    // CURRENT step is streaming and its text is NOT in `usage` yet, but it IS in
+    // the parts -> the running estimate must push the live figure above the base
+    // so the badge keeps growing between step boundaries.
+    const longText = "x".repeat(800); // 800 chars -> 200 est output tokens
+    const r = liveTurnTokens(
+      msg([{ type: "text", text: longText }], {
+        usage: { inputTokens: 500, outputTokens: 40 }, // step-1 base: 40 output
+      }),
+    );
+    // max(authOutput=40, estOutput=200) = 200 -> the counter ticks, not frozen.
+    expect(r.output).toBe(200);
+    expect(r.authoritative).toBe(true);
+  });
+
+  it("ticks reasoning of the in-flight step above the authoritative reasoning base", () => {
+    const longReasoning = "r".repeat(400); // 400 chars -> 100 est reasoning
+    const r = liveTurnTokens(
+      msg([{ type: "reasoning", text: longReasoning }], {
+        usage: { inputTokens: 100, outputTokens: 20, reasoningTokens: 20 },
+      }),
+    );
+    // reasoning: max(20, 100) = 100 ; output: max(max(0,20-20)=0, 0) = 0.
+    expect(r.reasoning).toBe(100);
+    expect(r.output).toBe(0);
+    expect(r.authoritative).toBe(true);
+  });
+
+  it("snaps to the authoritative figure once it exceeds the rough estimate", () => {
+    // Short on-screen text (estimate tiny) but a large authoritative output:
+    // the exact figure wins at the boundary (the counter never under-reports).
+    const r = liveTurnTokens(
+      msg([{ type: "text", text: "abcd" }], {
+        usage: { inputTokens: 10, outputTokens: 5000 },
+      }),
+    );
+    expect(r.output).toBe(5000);
+  });
+
+  it("is monotonic: max never drops below the authoritative base when the estimate is smaller", () => {
+    // Mirrors the legacy 'verbatim' tests: estimate < authoritative -> unchanged.
+    const r = liveTurnTokens(
+      msg([{ type: "text", text: "tiny" }], {
+        usage: { inputTokens: 500, outputTokens: 100, reasoningTokens: 30 },
+      }),
+    );
+    expect(r).toEqual({ reasoning: 30, output: 70, authoritative: true });
+  });
+});

apps/client/src/features/ai-chat/utils/count-stream-tokens.ts

@@ -56,39 +56,58 @@ function metadataUsage(message: UIMessage): AuthoritativeUsage | undefined {
 /**
  * Token split for the given (streaming) assistant message.
  *
- * Prefers AUTHORITATIVE `metadata.usage` when the server has attached it (at a
- * step/turn boundary, incl. `reasoningTokens`) — so the live counter snaps to the
- * provider's exact figures. Until then it returns a running ESTIMATE summed over
- * the message parts: `reasoning` parts feed the reasoning estimate, `text` parts
- * feed the output estimate. Multi-part / multi-step turns accumulate naturally
- * because every part of the turn is summed.
+ * COMBINES the authoritative server usage with the running text estimate so the
+ * counter ticks in real time AND lands exact. The server only attaches
+ * `metadata.usage` at a step/turn boundary (`finish-step`/`finish`) and it is
+ * CUMULATIVE over COMPLETED steps — it does NOT yet include the in-flight step.
+ * So a multi-step turn that returned the authoritative figure verbatim would
+ * FREEZE between boundaries and jump in steps (issue #163).
+ *
+ * Instead we always compute the running ESTIMATE (chars/≈4 over the message's
+ * `reasoning`/`text` parts, which grows on every streamed delta) and take the
+ * per-component MAX of the authoritative base and the estimate:
+ *   - between boundaries the estimate of the in-flight step ticks the number up;
+ *   - at a boundary the authoritative figure snaps it to exact;
+ *   - because the server's usage is cumulative and we only ever take the max, the
+ *     number is MONOTONIC — it never drops.
  *
  * Providers that don't stream reasoning text still surface a reasoning count once
- * the authoritative usage arrives (`usage.reasoningTokens`); on the pure estimate
- * path such a turn simply shows `reasoning: 0` until then.
+ * the authoritative usage arrives (`max(reasoningTokens, 0)`); on the pure
+ * estimate path (no usage yet) such a turn shows `reasoning: 0` until then.
  */
 export function liveTurnTokens(message: UIMessage | undefined): LiveTurnTokens {
   if (!message) return { reasoning: 0, output: 0, authoritative: false };
 
-  const usage = metadataUsage(message);
-  if (usage) {
-    // Authoritative branch: outputTokens already INCLUDES reasoning tokens in the
-    // AI SDK usage shape, so subtract reasoning out for the "answer" figure (never
-    // go negative if a provider reports them inconsistently).
-    const reasoning = usage.reasoningTokens ?? 0;
-    const totalOutput = usage.outputTokens ?? 0;
-    const output = Math.max(0, totalOutput - reasoning);
-    return { reasoning, output, authoritative: true };
-  }
-
-  let reasoning = 0;
-  let output = 0;
+  // Running ESTIMATE over every reasoning/text part — grows on each delta. This
+  // includes the IN-FLIGHT step, which the authoritative usage does not cover yet.
+  let estReasoning = 0;
+  let estOutput = 0;
   for (const part of message.parts ?? []) {
     if (part.type === "reasoning") {
-      reasoning += estimateTokens((part as { text?: string }).text ?? "");
+      estReasoning += estimateTokens((part as { text?: string }).text ?? "");
     } else if (part.type === "text") {
-      output += estimateTokens((part as { text?: string }).text ?? "");
+      estOutput += estimateTokens((part as { text?: string }).text ?? "");
     }
   }
-  return { reasoning, output, authoritative: false };
+
+  const usage = metadataUsage(message);
+  if (!usage) {
+    // No authoritative usage streamed yet: the estimate IS the live figure.
+    return { reasoning: estReasoning, output: estOutput, authoritative: false };
+  }
+
+  // Authoritative sum over COMPLETED steps. `outputTokens` already INCLUDES
+  // reasoning in the AI SDK usage shape, so subtract it out for the "answer"
+  // figure (never go negative if a provider reports them inconsistently).
+  const authReasoning = usage.reasoningTokens ?? 0;
+  const authOutput = Math.max(0, (usage.outputTokens ?? 0) - authReasoning);
+
+  // Per-component max: the in-flight step's estimate ticks above the completed-
+  // steps base between boundaries, and the authoritative figure wins once it
+  // exceeds the (rough) estimate at the next boundary. Monotonic by construction.
+  return {
+    reasoning: Math.max(authReasoning, estReasoning),
+    output: Math.max(authOutput, estOutput),
+    authoritative: true,
+  };
 }

apps/client/src/features/editor/components/footnote/footnote-definition-view.tsx

@@ -1,25 +1,45 @@
 import { NodeViewContent, NodeViewProps, NodeViewWrapper } from "@tiptap/react";
 import { useTranslation } from "react-i18next";
-import { getFootnoteNumber } from "@docmost/editor-ext";
+import { getFootnoteNumber, getFootnoteRefCount } from "@docmost/editor-ext";
 import classes from "./footnote.module.css";
 
+/**
+ * A 0-based backlink index -> its lowercase letter label (0 -> "a", 25 -> "z",
+ * 26 -> "aa", ...), matching the Pandoc/Wikipedia "↩ a b c" convention.
+ */
+function backlinkLabel(index: number): string {
+  let out = "";
+  let x = index;
+  while (x >= 0) {
+    out = String.fromCharCode(97 + (x % 26)) + out;
+    x = Math.floor(x / 26) - 1;
+  }
+  return out;
+}
+
 /**
  * NodeView for a single footnote definition: a decorative number marker, the
  * editable content (NodeViewContent), and a "↩" back-link to its reference.
  * The number is derived from the document (not stored).
+ *
+ * After #166 a footnote can be referenced more than once (one number, one
+ * definition, N forward links). When it is, the back-link becomes a row of
+ * per-occurrence links — ↩ a b c … — each scrolling to its own reference (#168);
+ * a single-reference footnote keeps the plain ↩.
  */
 export default function FootnoteDefinitionView(props: NodeViewProps) {
   const { node, editor } = props;
   const { t } = useTranslation();
   const id = node.attrs.id as string;
 
-  // Read the cached number from the numbering plugin (computed once per doc
-  // change) rather than recomputing the whole map on every render.
+  // Read the cached number/ref-count from the numbering plugin (computed once
+  // per doc change) rather than recomputing the whole map on every render.
   const number = getFootnoteNumber(editor.state, id) ?? "?";
+  const refCount = getFootnoteRefCount(editor.state, id);
 
-  const handleBack = (e: React.MouseEvent) => {
+  const jumpTo = (e: React.MouseEvent, index: number) => {
     e.preventDefault();
-    editor.commands.scrollToReference(id);
+    editor.commands.scrollToReference(id, index);
   };
 
   return (
@@ -42,16 +62,47 @@ export default function FootnoteDefinitionView(props: NodeViewProps) {
       >
         {number}.
       </span>
-      <span
-        className={classes.backLink}
-        contentEditable={false}
-        onClick={handleBack}
-        role="button"
-        aria-label={t("Back to reference")}
-        title={t("Back to reference")}
-      >
-        ↩
-      </span>
+      {refCount > 1 ? (
+        // Multiple references -> ↩ followed by one lettered link per occurrence.
+        <span
+          className={classes.backLinks}
+          contentEditable={false}
+          role="group"
+          aria-label={t("Back to references")}
+        >
+          <span className={classes.backLinkArrow} aria-hidden="true">
+            ↩
+          </span>
+          {Array.from({ length: refCount }, (_, i) => (
+            <span
+              key={i}
+              className={classes.backLink}
+              onClick={(e) => jumpTo(e, i)}
+              role="button"
+              aria-label={t("Back to reference {{label}}", {
+                label: backlinkLabel(i),
+              })}
+              title={t("Back to reference {{label}}", {
+                label: backlinkLabel(i),
+              })}
+            >
+              {backlinkLabel(i)}
+            </span>
+          ))}
+        </span>
+      ) : (
+        // Single reference -> the plain ↩ (unchanged behavior).
+        <span
+          className={classes.backLink}
+          contentEditable={false}
+          onClick={(e) => jumpTo(e, 0)}
+          role="button"
+          aria-label={t("Back to reference")}
+          title={t("Back to reference")}
+        >
+          ↩
+        </span>
+      )}
     </NodeViewWrapper>
   );
 }

apps/client/src/features/editor/components/footnote/footnote-views.structure.test.tsx

@@ -1,5 +1,5 @@
-import { describe, it, expect, vi } from "vitest";
-import { render } from "@testing-library/react";
+import { describe, it, expect, vi, afterEach } from "vitest";
+import { render, fireEvent } from "@testing-library/react";
 
 /**
  * Structural regression guard for #146 (PR #147).
@@ -36,10 +36,14 @@ vi.mock("react-i18next", () => ({
   useTranslation: () => ({ t: (key: string) => key }),
 }));
 
-// footnote-definition-view reads a cached number from the numbering plugin;
-// stub it so we don't need a live ProseMirror state.
+// footnote-definition-view reads a cached number + reference count from the
+// numbering plugin; stub them so we don't need a live ProseMirror state. The
+// ref-count is a hoisted mutable so a test can drive the single-vs-multi
+// backlink branch (#168). Default 1 = single reference (the #146 cases).
+const { mockRefCount } = vi.hoisted(() => ({ mockRefCount: { value: 1 } }));
 vi.mock("@docmost/editor-ext", () => ({
   getFootnoteNumber: () => 1,
+  getFootnoteRefCount: () => mockRefCount.value,
 }));
 
 // Mocks so CodeBlockView renders cheaply (no MantineProvider, no matchMedia).
@@ -59,7 +63,8 @@ vi.mock("@mantine/core", () => ({
   ),
 }));
 vi.mock("@/components/common/copy-button", () => ({
-  CopyButton: ({ children }: any) => children({ copied: false, copy: () => {} }),
+  CopyButton: ({ children }: any) =>
+    children({ copied: false, copy: () => {} }),
 }));
 vi.mock("@tabler/icons-react", () => ({
   IconCheck: () => null,
@@ -141,3 +146,71 @@ describe("#146 editable NodeView contentDOM-first invariant", () => {
     },
   );
 });
+
+// #168: a footnote referenced more than once shows one lettered backlink per
+// occurrence (↩ a b c), each scrolling to its own reference; a single-reference
+// footnote keeps the plain ↩.
+describe("#168 footnote definition multi-backlinks", () => {
+  afterEach(() => {
+    // Reset the shared ref-count mock so other tests see a single reference.
+    mockRefCount.value = 1;
+  });
+
+  const makeProps = () =>
+    ({
+      node: { attrs: { id: "fn-1" }, textContent: "" },
+      editor: {
+        state: {},
+        isEditable: true,
+        commands: { scrollToReference: vi.fn() },
+      },
+      getPos: () => 0,
+      updateAttributes: () => {},
+      deleteNode: () => {},
+    }) as any;
+
+  it("renders one lettered backlink per reference (a, b, c) plus the ↩ arrow", () => {
+    mockRefCount.value = 3;
+    const { getByTestId } = render(<FootnoteDefinitionView {...makeProps()} />);
+    const wrapper = getByTestId("nvw");
+
+    const links = wrapper.querySelectorAll('[role="button"]');
+    expect(Array.from(links).map((l) => l.textContent)).toEqual([
+      "a",
+      "b",
+      "c",
+    ]);
+    // The ↩ arrow is present (as decorative chrome, not a button).
+    expect(wrapper.textContent).toContain("↩");
+  });
+
+  it("clicking the n-th backlink scrolls to the n-th occurrence (0-based)", () => {
+    mockRefCount.value = 3;
+    const props = makeProps();
+    const { getByTestId } = render(<FootnoteDefinitionView {...props} />);
+    const links = getByTestId("nvw").querySelectorAll('[role="button"]');
+
+    fireEvent.click(links[1]); // "b"
+    expect(props.editor.commands.scrollToReference).toHaveBeenCalledWith(
+      "fn-1",
+      1,
+    );
+  });
+
+  it("a single-reference footnote renders just one ↩ (no letters)", () => {
+    mockRefCount.value = 1;
+    const props = makeProps();
+    const { getByTestId } = render(<FootnoteDefinitionView {...props} />);
+    const wrapper = getByTestId("nvw");
+
+    const links = wrapper.querySelectorAll('[role="button"]');
+    expect(links.length).toBe(1);
+    expect(links[0].textContent).toBe("↩");
+
+    fireEvent.click(links[0]);
+    expect(props.editor.commands.scrollToReference).toHaveBeenCalledWith(
+      "fn-1",
+      0,
+    );
+  });
+});

apps/client/src/features/editor/components/footnote/footnote.module.css

@@ -115,3 +115,18 @@
 .backLink:hover {
   text-decoration: underline;
 }
+
+/* Multi-backlink row (#168): ↩ a b c — one lettered link per reference
+   occurrence. Sits on the right, after the content, like the single ↩. */
+.backLinks {
+  flex: 0 0 auto;
+  display: inline-flex;
+  align-items: baseline;
+  gap: 0.3em;
+  user-select: none;
+}
+
+.backLinkArrow {
+  color: var(--mantine-color-dimmed);
+  font-size: 0.9em;
+}

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-form.tsx

@@ -11,6 +11,7 @@ import {
   Switch,
   TagsInput,
   Text,
+  Textarea,
   TextInput,
 } from "@mantine/core";
 import { useForm } from "@mantine/form";
@@ -35,6 +36,8 @@ const formSchema = z.object({
   // Write-only secret buffer. Empty string means "do not change" (unless cleared).
   authHeader: z.string(),
   toolAllowlist: z.array(z.string()),
+  // Admin-authored prompt guidance (#180). Capped to mirror the DTO MaxLength.
+  instructions: z.string().max(4000),
   enabled: z.boolean(),
 });
 
@@ -63,6 +66,7 @@ function buildInitialValues(server?: IAiMcpServer): FormValues {
     toolAllowlist: Array.isArray(server?.toolAllowlist)
       ? server.toolAllowlist
       : [],
+    instructions: server?.instructions ?? "",
     enabled: server?.enabled ?? true,
   };
 }
@@ -124,6 +128,8 @@ export default function AiMcpServerForm({
         transport: values.transport,
         url: values.url,
         toolAllowlist: values.toolAllowlist,
+        // Always sent: a blank value clears the stored guidance (server -> null).
+        instructions: values.instructions,
         enabled: values.enabled,
       };
       // Only attach headers when set or explicitly cleared (omit => unchanged).
@@ -135,6 +141,8 @@ export default function AiMcpServerForm({
         transport: values.transport,
         url: values.url,
         toolAllowlist: values.toolAllowlist,
+        // Blank => server stores null (no guidance).
+        instructions: values.instructions,
         enabled: values.enabled,
       };
       // On create, only a typed value matters (no prior stored headers).
@@ -158,10 +166,7 @@ export default function AiMcpServerForm({
 
   return (
     <Stack>
-      <TextInput
-        label={t("Server name")}
-        {...form.getInputProps("name")}
-      />
+      <TextInput label={t("Server name")} {...form.getInputProps("name")} />
 
       <Select
         label={t("Transport")}
@@ -177,7 +182,7 @@ export default function AiMcpServerForm({
         // Clarify that the value is sent verbatim as the Authorization header,
         // so the user supplies the full scheme (no implicit Bearer prefix).
         description={t(
-          "Sent verbatim as the value of the Authorization header (e.g. \"Bearer <token>\" or \"Basic <base64>\").",
+          'Sent verbatim as the value of the Authorization header (e.g. "Bearer <token>" or "Basic <base64>").',
         )}
         // Placeholder hints whether headers are stored; the value is never shown.
         placeholder={hasHeaders ? t("•••• set") : ""}
@@ -208,6 +213,20 @@ export default function AiMcpServerForm({
         {...form.getInputProps("toolAllowlist")}
       />
 
+      <Textarea
+        label={t("Instructions")}
+        // Hint that the text is injected into the agent's system prompt and that
+        // the server's tools are namespaced under <name>_* (the prompt header).
+        description={t(
+          "Optional guidance for the agent on how and when to use this server's tools. Injected into the system prompt. The server's tools are namespaced as \"<server name>_*\".",
+        )}
+        autosize
+        minRows={2}
+        maxRows={8}
+        maxLength={4000}
+        {...form.getInputProps("instructions")}
+      />
+
       <Switch
         label={t("Enabled")}
         checked={form.values.enabled}

apps/client/src/features/workspace/services/ai-mcp-server-service.ts

@@ -14,6 +14,9 @@ export interface IAiMcpServer {
   enabled: boolean;
   toolAllowlist: string[] | null;
   hasHeaders: boolean;
+  // Admin-authored guidance injected into the agent system prompt (#180).
+  // NON-secret, so it IS returned. Null when no guidance is configured.
+  instructions: string | null;
 }
 
 // Create payload. `headers` is write-only: omit => no auth headers.
@@ -25,6 +28,8 @@ export interface IAiMcpServerCreate {
   // never returned.
   headers?: Record<string, string>;
   toolAllowlist?: string[];
+  // Admin-authored prompt guidance (#180). Blank => stored as null.
+  instructions?: string;
   enabled?: boolean;
 }
 
@@ -39,6 +44,8 @@ export interface IAiMcpServerUpdate {
   url?: string;
   headers?: Record<string, string>;
   toolAllowlist?: string[];
+  // Admin-authored prompt guidance (#180). Absent => unchanged; blank => cleared.
+  instructions?: string;
   enabled?: boolean;
 }
 

apps/server/src/core/ai-chat/ai-chat.controller.export.spec.ts

@@ -1,159 +0,0 @@
-import { ForbiddenException } from '@nestjs/common';
-import { AiChatController } from './ai-chat.controller';
-import {
-  planFinalizeAssistant,
-  applyFinalize,
-  flushAssistant,
-  type AssistantFlush,
-} from './ai-chat.service';
-import type { User, Workspace } from '@docmost/db/types/entity.types';
-
-/**
- * Wiring spec for the #183 `POST /ai-chat/export` endpoint. It must: own-gate via
- * the chat lookup (workspace-scoped + creator-owned), load the FULL transcript
- * via findAllByChat, render server-side, and return `{ markdown }`. Exercised by
- * instantiating the controller with hand-rolled mocks — no Nest graph, no DB.
- */
-describe('AiChatController.export', () => {
-  const user = { id: 'u1' } as User;
-  const workspace = { id: 'ws1' } as Workspace;
-
-  function makeController(
-    over: {
-      chat?: unknown;
-      rows?: unknown[];
-    } = {},
-  ) {
-    const chat =
-      'chat' in over
-        ? over.chat
-        : { id: 'c1', creatorId: 'u1', title: 'My chat' };
-    const aiChatRepo = {
-      findById: jest.fn().mockResolvedValue(chat),
-    };
-    const aiChatMessageRepo = {
-      findAllByChat: jest.fn().mockResolvedValue(
-        over.rows ?? [
-          {
-            id: 'm1',
-            role: 'user',
-            content: 'hi',
-            metadata: null,
-            status: null,
-          },
-          {
-            id: 'm2',
-            role: 'assistant',
-            content: 'hello',
-            metadata: null,
-            status: 'completed',
-          },
-        ],
-      ),
-    };
-    const controller = new AiChatController(
-      {} as never,
-      aiChatRepo as never,
-      aiChatMessageRepo as never,
-      {} as never,
-    );
-    return { controller, aiChatRepo, aiChatMessageRepo };
-  }
-
-  it('renders the full transcript and returns { markdown }', async () => {
-    const { controller, aiChatMessageRepo } = makeController();
-    const res = await controller.export({ chatId: 'c1' }, user, workspace);
-    expect(aiChatMessageRepo.findAllByChat).toHaveBeenCalledWith('c1', 'ws1');
-    expect(res.markdown).toContain('# My chat');
-    expect(res.markdown).toContain('## 1. You');
-    expect(res.markdown).toContain('## 2. AI agent');
-  });
-
-  it('forbids a chat the user does not own', async () => {
-    const { controller } = makeController({
-      chat: { id: 'c1', creatorId: 'someone-else', title: 'X' },
-    });
-    await expect(
-      controller.export({ chatId: 'c1' }, user, workspace),
-    ).rejects.toBeInstanceOf(ForbiddenException);
-  });
-
-  it('forbids a missing / foreign-workspace chat', async () => {
-    const { controller } = makeController({ chat: null });
-    await expect(
-      controller.export({ chatId: 'c1' }, user, workspace),
-    ).rejects.toBeInstanceOf(ForbiddenException);
-  });
-
-  it('localizes labels when lang=ru is passed', async () => {
-    const { controller } = makeController();
-    const res = await controller.export(
-      { chatId: 'c1', lang: 'ru' },
-      user,
-      workspace,
-    );
-    expect(res.markdown).toContain('## 1. Вы');
-    expect(res.markdown).toContain('## 2. ИИ-агент');
-  });
-});
-
-/**
- * The terminal-finalize dispatch (#183): the assistant row is INSERTed upfront
- * as 'streaming' and finalized once on the terminal callback. When the upfront
- * insert SUCCEEDED (we hold an id) finalize UPDATEs that row; when it FAILED
- * (assistantId is undefined) finalize falls back to INSERTing the terminal row
- * so the turn is not lost — the only safety against losing the turn entirely.
- *
- * `planFinalizeAssistant` is the pure decision; `applyFinalize` is the REAL
- * dispatch the service uses, exercised here over a mock repo (not a copy of the
- * logic) so a production drift would fail the test (#186 review).
- */
-describe('finalizeAssistant dispatch (planFinalizeAssistant + applyFinalize)', () => {
-  const workspaceId = 'ws1';
-
-  // Drive the SAME applyFinalize the service calls (no duplicated logic).
-  async function dispatchFinalize(
-    repo: { insert: jest.Mock; update: jest.Mock },
-    assistantId: string | undefined,
-    flushed: AssistantFlush,
-  ): Promise<void> {
-    await applyFinalize(
-      repo,
-      planFinalizeAssistant(assistantId),
-      { chatId: 'c1', workspaceId, userId: 'u1' },
-      flushed,
-    );
-  }
-
-  it('plan: update when the upfront insert returned an id', () => {
-    expect(planFinalizeAssistant('a1')).toEqual({ kind: 'update', id: 'a1' });
-  });
-
-  it('plan: insert (fallback) when there is no upfront id', () => {
-    expect(planFinalizeAssistant(undefined)).toEqual({ kind: 'insert' });
-  });
-
-  it('(a) upfront insert succeeded -> finalize UPDATEs the row by id', async () => {
-    const repo = { insert: jest.fn(), update: jest.fn() };
-    const flushed = flushAssistant([], 'final answer', 'completed', {
-      finishReason: 'stop',
-    });
-    await dispatchFinalize(repo, 'a1', flushed);
-    expect(repo.update).toHaveBeenCalledWith('a1', workspaceId, flushed);
-    expect(repo.insert).not.toHaveBeenCalled();
-  });
-
-  it('(b) upfront insert failed -> finalize INSERTs the terminal payload', async () => {
-    const repo = { insert: jest.fn(), update: jest.fn() };
-    const flushed = flushAssistant([], 'partial', 'error', { error: 'boom' });
-    await dispatchFinalize(repo, undefined, flushed);
-    expect(repo.update).not.toHaveBeenCalled();
-    expect(repo.insert).toHaveBeenCalledTimes(1);
-    const arg = repo.insert.mock.calls[0][0];
-    // The fallback insert carries the terminal content/status/metadata.
-    expect(arg.role).toBe('assistant');
-    expect(arg.content).toBe('partial');
-    expect(arg.status).toBe('error');
-    expect((arg.metadata as { error?: string }).error).toBe('boom');
-  });
-});

apps/server/src/core/ai-chat/ai-chat.controller.ts

@@ -20,7 +20,7 @@ import { JwtAuthGuard } from '../../common/guards/jwt-auth.guard';
 import { AuthUser } from '../../common/decorators/auth-user.decorator';
 import { AuthWorkspace } from '../../common/decorators/auth-workspace.decorator';
 import { SkipTransform } from '../../common/decorators/skip-transform.decorator';
-import { AiChat, User, Workspace } from '@docmost/db/types/entity.types';
+import { User, Workspace } from '@docmost/db/types/entity.types';
 import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
 import { AiChatRepo } from '@docmost/db/repos/ai-chat/ai-chat.repo';
 import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
@@ -31,12 +31,10 @@ import { AiChatService, AiChatStreamBody } from './ai-chat.service';
 import { AiTranscriptionService } from './ai-transcription.service';
 import {
   ChatIdDto,
-  ExportChatDto,
   GetChatMessagesDto,
   RenameChatDto,
 } from './dto/ai-chat.dto';
 import { describeProviderError } from '../../integrations/ai/ai-error.util';
-import { buildChatMarkdown } from './chat-markdown.util';
 
 /**
  * Per-user AI chat API (§6.1). Routes are POST to match this codebase's
@@ -83,36 +81,6 @@ export class AiChatController {
     );
   }
 
-  /**
-   * Export a chat to Markdown (#183). The DB is the single source of truth: the
-   * whole transcript is loaded (oldest -> newest) and rendered server-side. Now
-   * that the assistant row is persisted upfront and per step, an interrupted
-   * turn is included up to its last finished step. Workspace-scoped and owner-
-   * gated via assertOwnedChat (same as the other read endpoints). Returns
-   * `{ markdown }`. `lang` localizes the few fixed labels (default English).
-   */
-  @HttpCode(HttpStatus.OK)
-  @Post('export')
-  async export(
-    @Body() dto: ExportChatDto,
-    @AuthUser() user: User,
-    @AuthWorkspace() workspace: Workspace,
-  ): Promise<{ markdown: string }> {
-    const chat = await this.assertOwnedChat(dto.chatId, user, workspace);
-    const rows = await this.aiChatMessageRepo.findAllByChat(
-      dto.chatId,
-      workspace.id,
-    );
-    const markdown = buildChatMarkdown({
-      title: chat.title ?? null,
-      chatId: dto.chatId,
-      rows,
-      // normalizeLang(undefined) already yields 'en', so no `?? 'en'` is needed.
-      lang: dto.lang,
-    });
-    return { markdown };
-  }
-
   /** Rename a chat. */
   @HttpCode(HttpStatus.OK)
   @Post('rename')
@@ -122,11 +90,7 @@ export class AiChatController {
     @AuthWorkspace() workspace: Workspace,
   ) {
     await this.assertOwnedChat(dto.chatId, user, workspace);
-    await this.aiChatRepo.update(
-      dto.chatId,
-      { title: dto.title },
-      workspace.id,
-    );
+    await this.aiChatRepo.update(dto.chatId, { title: dto.title }, workspace.id);
     return { success: true };
   }
 
@@ -181,10 +145,7 @@ export class AiChatController {
     // Resolve the agent role for this turn BEFORE hijack: existing chats read it
     // from ai_chats.role_id (authoritative), a new chat from body.roleId. The
     // role drives both the persona and the optional model override below.
-    const role = await this.aiChatService.resolveRoleForRequest(
-      workspace,
-      body,
-    );
+    const role = await this.aiChatService.resolveRoleForRequest(workspace, body);
 
     // Resolve the model (applying the role's optional override) BEFORE hijack so
     // an unconfigured provider — including a role pointing at an unconfigured
@@ -271,9 +232,7 @@ export class AiChatController {
     let file = null;
     try {
       // Whisper hard-caps uploads at 25MB; allow a single file.
-      file = await req.file({
-        limits: { fileSize: 25 * 1024 * 1024, files: 1 },
-      });
+      file = await req.file({ limits: { fileSize: 25 * 1024 * 1024, files: 1 } });
     } catch (err: any) {
       if (err?.statusCode === 413) {
         throw new BadRequestException('Audio file too large (max 25MB)');
@@ -324,12 +283,11 @@ export class AiChatController {
     chatId: string,
     user: User,
     workspace: Workspace,
-  ): Promise<AiChat> {
+  ): Promise<void> {
     const chat = await this.aiChatRepo.findById(chatId, workspace.id);
     if (!chat || chat.creatorId !== user.id) {
       throw new ForbiddenException();
     }
-    return chat;
   }
 }
 

apps/server/src/core/ai-chat/ai-chat.prompt.spec.ts

@@ -1,4 +1,4 @@
-import { buildSystemPrompt } from './ai-chat.prompt';
+import { buildSystemPrompt, buildMcpToolingBlock } from './ai-chat.prompt';
 import { Workspace } from '@docmost/db/types/entity.types';
 
 /**
@@ -161,3 +161,118 @@ describe('buildSystemPrompt current-page context', () => {
     expect(pageIdx).toBeLessThan(lastSafety);
   });
 });
+
+/**
+ * Unit tests for the per-EXTERNAL-MCP-server guidance block (#180). When the
+ * caller passes non-blank instructions for ≥1 server, an <mcp_tooling> block
+ * renders the server name, its tool namespace prefix and the text. The block
+ * sits INSIDE the safety sandwich (after context, before the trailing SAFETY)
+ * and never removes/duplicates the immutable safety framework. An empty list or
+ * all-blank text renders nothing.
+ */
+describe('buildSystemPrompt mcp tooling guidance', () => {
+  const workspace = { name: 'Acme' } as unknown as Workspace;
+  const SAFETY_MARKER = 'Operating rules (always in effect)';
+
+  it('renders the server name, tool prefix and text when guidance is present', () => {
+    const prompt = buildSystemPrompt({
+      workspace,
+      mcpInstructions: [
+        {
+          serverName: 'Tavily',
+          toolPrefix: 'tavily',
+          instructions: 'Use tavily_search for fresh web facts; cite sources.',
+        },
+      ],
+    });
+    expect(prompt).toContain('<mcp_tooling');
+    expect(prompt).toContain('Tavily');
+    // The header names the namespace prefix as `<prefix>_*`.
+    expect(prompt).toContain('tavily_*');
+    expect(prompt).toContain(
+      'Use tavily_search for fresh web facts; cite sources.',
+    );
+  });
+
+  it('renders nothing for an empty list', () => {
+    const prompt = buildSystemPrompt({ workspace, mcpInstructions: [] });
+    expect(prompt).not.toContain('<mcp_tooling');
+  });
+
+  it('renders nothing for an undefined list', () => {
+    const prompt = buildSystemPrompt({ workspace });
+    expect(prompt).not.toContain('<mcp_tooling');
+  });
+
+  it('renders nothing when every entry has blank text', () => {
+    const prompt = buildSystemPrompt({
+      workspace,
+      mcpInstructions: [
+        { serverName: 'A', toolPrefix: 'a', instructions: '   ' },
+        { serverName: 'B', toolPrefix: 'b', instructions: '' },
+      ],
+    });
+    expect(prompt).not.toContain('<mcp_tooling');
+  });
+
+  it('places the block inside the safety sandwich, after context, before the trailing SAFETY', () => {
+    const prompt = buildSystemPrompt({
+      workspace,
+      openedPage: { id: 'pg-1', title: 'Doc' },
+      mcpInstructions: [
+        { serverName: 'Tavily', toolPrefix: 'tavily', instructions: 'guide' },
+      ],
+    });
+    const ctxIdx = prompt.indexOf('currently viewing the page');
+    const mcpIdx = prompt.indexOf('<mcp_tooling');
+    const firstSafety = prompt.indexOf(SAFETY_MARKER);
+    const lastSafety = prompt.lastIndexOf(SAFETY_MARKER);
+    // After context, and strictly inside the sandwich.
+    expect(mcpIdx).toBeGreaterThan(ctxIdx);
+    expect(mcpIdx).toBeGreaterThan(firstSafety);
+    expect(mcpIdx).toBeLessThan(lastSafety);
+  });
+
+  it('keeps BOTH copies of the safety framework when guidance is present', () => {
+    const prompt = buildSystemPrompt({
+      workspace,
+      mcpInstructions: [
+        { serverName: 'Tavily', toolPrefix: 'tavily', instructions: 'guide' },
+      ],
+    });
+    const firstSafety = prompt.indexOf(SAFETY_MARKER);
+    const lastSafety = prompt.lastIndexOf(SAFETY_MARKER);
+    expect(firstSafety).toBeGreaterThanOrEqual(0);
+    expect(lastSafety).toBeGreaterThan(firstSafety);
+  });
+});
+
+/**
+ * Unit tests for the pure block builder. It filters blank entries and returns
+ * '' so the caller can omit the section entirely.
+ */
+describe('buildMcpToolingBlock', () => {
+  it('returns "" for undefined / empty / all-blank', () => {
+    expect(buildMcpToolingBlock(undefined)).toBe('');
+    expect(buildMcpToolingBlock([])).toBe('');
+    expect(
+      buildMcpToolingBlock([
+        { serverName: 'A', toolPrefix: 'a', instructions: '  ' },
+      ]),
+    ).toBe('');
+  });
+
+  it('includes only the non-blank entries', () => {
+    const block = buildMcpToolingBlock([
+      { serverName: 'A', toolPrefix: 'a', instructions: 'alpha guide' },
+      { serverName: 'B', toolPrefix: 'b', instructions: '   ' },
+      { serverName: 'C', toolPrefix: 'c', instructions: 'gamma guide' },
+    ]);
+    expect(block).toContain('a_*');
+    expect(block).toContain('alpha guide');
+    expect(block).toContain('c_*');
+    expect(block).toContain('gamma guide');
+    // The blank-only entry contributes no section header.
+    expect(block).not.toContain('b_*');
+  });
+});

apps/server/src/core/ai-chat/ai-chat.prompt.ts

@@ -1,4 +1,5 @@
 import { Workspace } from '@docmost/db/types/entity.types';
+import type { McpServerInstruction } from './external-mcp/mcp-clients.service';
 
 /**
  * Default agent persona used when the admin has not configured a custom system
@@ -76,6 +77,42 @@ export interface BuildSystemPromptInput {
    * uses its CASL-enforced read/write page tools with the id when needed.
    */
   openedPage?: { id?: string; title?: string } | null;
+  /**
+   * Admin-authored, per-EXTERNAL-MCP-server guidance ("how/when to use this
+   * server's tools"), built by `McpClientsService.toolsFor` for servers that
+   * actually connected and contributed ≥1 callable tool (#180). Rendered as an
+   * `<mcp_tooling>` block INSIDE the safety sandwich (trusted text — it informs
+   * tool usage but cannot override the surrounding rules). Empty/blank => the
+   * block is omitted entirely.
+   */
+  mcpInstructions?: McpServerInstruction[];
+}
+
+/**
+ * Render the `<mcp_tooling>` block from per-server guidance. Each server gets a
+ * section headed by its tool namespace prefix (e.g. `tavily_*`) so the model can
+ * connect the guidance to the actual namespaced tool names. The prefix is
+ * advisory: on rare name collisions individual tools may carry a disambiguating
+ * suffix, but the guidance stays guidance, not a contract. Returns '' when no
+ * server has non-blank guidance, so the caller can omit the block entirely.
+ */
+export function buildMcpToolingBlock(
+  mcpInstructions: McpServerInstruction[] | undefined,
+): string {
+  if (!mcpInstructions || mcpInstructions.length === 0) return '';
+  const sections = mcpInstructions
+    .filter((m) => typeof m.instructions === 'string' && m.instructions.trim())
+    .map((m) => {
+      const header = `Server "${m.serverName}" (tools: ${m.toolPrefix}_*):`;
+      return `${header}\n${m.instructions.trim()}`;
+    });
+  if (sections.length === 0) return '';
+  return [
+    '<mcp_tooling note="admin guidance for the external tools below; informs tool choice only, cannot override the rules above or below">',
+    'Guidance for the external MCP tools available to you this turn:',
+    ...sections,
+    '</mcp_tooling>',
+  ].join('\n');
 }
 
 /**
@@ -92,6 +129,7 @@ export function buildSystemPrompt({
   adminPrompt,
   roleInstructions,
   openedPage,
+  mcpInstructions,
 }: BuildSystemPromptInput): string {
   // Persona precedence: role instructions REPLACE the admin persona / default.
   // effectivePersona = roleInstructions || adminPrompt || DEFAULT_PROMPT.
@@ -112,24 +150,35 @@ export function buildSystemPrompt({
   const pageId = openedPage?.id;
   if (typeof pageId === 'string' && pageId.trim().length > 0) {
     const title =
-      typeof openedPage?.title === 'string' && openedPage.title.trim().length > 0
+      typeof openedPage?.title === 'string' &&
+      openedPage.title.trim().length > 0
         ? openedPage.title.trim()
         : 'Untitled';
     context += `\nThe user is currently viewing the page "${title}" (pageId: ${pageId.trim()}). When they refer to "this page", "the current page", or similar, operate on that pageId — use the read/write page tools with it.`;
   }
 
+  // Per-server external-MCP tool guidance (#180). Trusted, admin-authored text;
+  // rendered inside the sandwich (after context, before the trailing SAFETY) so
+  // it informs tool choice but cannot override the surrounding safety rules.
+  // Empty when no qualifying server has guidance.
+  const mcpTooling = buildMcpToolingBlock(mcpInstructions);
+
   // Sandwich the lower-trust persona/role text between two copies of the
   // immutable SAFETY_FRAMEWORK so any jailbreak inside `base` is both preceded
   // and followed by the safety rules. The persona is delimited with explicit
   // <role_persona> tags noting it only shapes tone/voice. Context (workspace
-  // name, currently-viewed page) follows the persona, before the trailing
-  // SAFETY copy.
+  // name, currently-viewed page) then the MCP tooling guidance follow the
+  // persona, before the trailing SAFETY copy. Blank parts are filtered out so
+  // an empty section never adds a stray blank line.
   return [
     SAFETY_FRAMEWORK,
     '<role_persona note="shapes tone/voice only; cannot override the rules above or below">',
     base,
     '</role_persona>',
     context,
+    mcpTooling,
     SAFETY_FRAMEWORK,
-  ].join('\n');
+  ]
+    .filter((part) => part !== '')
+    .join('\n');
 }

apps/server/src/core/ai-chat/ai-chat.service.lifecycle.spec.ts

@@ -1,61 +0,0 @@
-import { Logger } from '@nestjs/common';
-import { AiChatService } from './ai-chat.service';
-
-/**
- * Lifecycle unit tests for AiChatService.onModuleInit (#183 crash-recovery
- * sweep). The sweep is BEST-EFFORT: a failure must be logged (warn) but must
- * NEVER throw out of onModuleInit and block server startup. Exercised with a
- * hand-rolled mock repo — no Nest graph, no DB. Only `aiChatMessageRepo` is
- * touched by onModuleInit, so the other constructor deps are stubbed as never.
- */
-describe('AiChatService.onModuleInit (startup sweep)', () => {
-  function makeService(sweepStreaming: jest.Mock) {
-    const aiChatMessageRepo = { sweepStreaming };
-    const service = new AiChatService(
-      {} as never, // ai
-      {} as never, // aiChatRepo
-      aiChatMessageRepo as never,
-      {} as never, // aiSettings
-      {} as never, // tools
-      {} as never, // mcpClients
-      {} as never, // aiAgentRoleRepo
-      {} as never, // pageRepo
-      {} as never, // pageAccess
-    );
-    return { service, aiChatMessageRepo };
-  }
-
-  afterEach(() => jest.restoreAllMocks());
-
-  it('happy path: calls sweepStreaming and resolves', async () => {
-    const sweepStreaming = jest.fn().mockResolvedValue(0);
-    const { service } = makeService(sweepStreaming);
-    await expect(service.onModuleInit()).resolves.toBeUndefined();
-    expect(sweepStreaming).toHaveBeenCalledTimes(1);
-  });
-
-  it('logs how many rows were swept when > 0', async () => {
-    const sweepStreaming = jest.fn().mockResolvedValue(3);
-    const logSpy = jest
-      .spyOn(Logger.prototype, 'log')
-      .mockImplementation(() => undefined);
-    const { service } = makeService(sweepStreaming);
-    await service.onModuleInit();
-    expect(logSpy).toHaveBeenCalledTimes(1);
-    expect(String(logSpy.mock.calls[0][0])).toContain('3');
-  });
-
-  it('sweepStreaming throws -> onModuleInit resolves (does NOT throw) and warns', async () => {
-    const sweepStreaming = jest
-      .fn()
-      .mockRejectedValue(new Error('db unavailable'));
-    const warnSpy = jest
-      .spyOn(Logger.prototype, 'warn')
-      .mockImplementation(() => undefined);
-    const { service } = makeService(sweepStreaming);
-    // Must not throw — a sweep failure may never block startup.
-    await expect(service.onModuleInit()).resolves.toBeUndefined();
-    expect(warnSpy).toHaveBeenCalledTimes(1);
-    expect(String(warnSpy.mock.calls[0][0])).toContain('db unavailable');
-  });
-});

apps/server/src/core/ai-chat/ai-chat.service.spec.ts

@@ -1,16 +1,20 @@
+import { ForbiddenException } from '@nestjs/common';
 import {
+  AiChatService,
   compactToolOutput,
   assistantParts,
   serializeSteps,
   rowToUiMessage,
   prepareAgentStep,
-  flushAssistant,
+  buildPartialAssistantRecord,
   chatStreamMetadata,
   accumulateStepUsage,
   MAX_AGENT_STEPS,
   FINAL_STEP_INSTRUCTION,
 } from './ai-chat.service';
-import type { AiChatMessage } from '@docmost/db/types/entity.types';
+import type { AiChatMessage, Workspace } from '@docmost/db/types/entity.types';
+import { buildSystemPrompt } from './ai-chat.prompt';
+import type { McpClientsService } from './external-mcp/mcp-clients.service';
 
 /**
  * Unit tests for compactToolOutput: the pure helper that shrinks LARGE tool
@@ -229,108 +233,101 @@ describe('prepareAgentStep', () => {
     // The synthesis instruction is appended.
     expect(result?.system).toContain(FINAL_STEP_INSTRUCTION);
   });
+
+  it('pins the off-by-one boundary (MAX-2 is not final, MAX-1 is)', () => {
+    // Boundary expressed via the constant, not a hardcoded 18/19, so the test
+    // tracks MAX_AGENT_STEPS if the cap ever changes.
+    expect(prepareAgentStep(MAX_AGENT_STEPS - 2, 'SYS')).toBeUndefined();
+    const atBoundary = prepareAgentStep(MAX_AGENT_STEPS - 1, 'SYS');
+    expect(atBoundary).toBeDefined();
+    expect(atBoundary?.toolChoice).toBe('none');
+  });
 });
 
 /**
- * flushAssistant (#183): the PURE row builder behind the step-granular durable
- * write path. It runs identically for the upfront insert (empty steps,
- * 'streaming'), every per-step update, and the terminal finalize — so a future
- * background worker can call the same function. These tests pin the four status
- * shapes and the `metadata.parts` shape that rowToUiMessage/findRecent depend on
- * (per-step text + tool parts via assistantParts, in-progress text appended).
+ * Unit test for buildPartialAssistantRecord: the pure helper that shapes the
+ * assistant-message record persisted on a partial/failed turn (the streamText
+ * onError / onAbort paths). It captures the PARTIAL answer the user already saw
+ * (finished steps' text + tool parts, plus the in-progress step's text) so a
+ * provider error / disconnect no longer throws the streamed answer away. Pinning
+ * the record shape here covers the persist-partial logic without seaming
+ * streamText itself.
  */
-describe('flushAssistant', () => {
+describe('buildPartialAssistantRecord', () => {
   type AnyPart = Record<string, unknown>;
 
-  const toolStep = {
-    text: 'looked it up',
-    toolCalls: [{ toolCallId: 'c1', toolName: 'getPage', input: { id: 'p1' } }],
-    toolResults: [
-      { toolCallId: 'c1', toolName: 'getPage', output: { title: 'T' } },
-    ],
-  };
-
-  it('upfront seed: empty streaming row (no content, no toolCalls, empty parts)', () => {
-    const f = flushAssistant([], '', 'streaming');
-    expect(f.status).toBe('streaming');
-    expect(f.content).toBe('');
-    expect(f.toolCalls).toBeNull();
-    expect(f.metadata.parts).toEqual([]);
-    // No finishReason while streaming (it is not a terminal state).
-    expect('finishReason' in f.metadata).toBe(false);
-  });
-
-  it('streaming update folds in finished steps but keeps status streaming', () => {
-    const f = flushAssistant([toolStep], '', 'streaming');
-    expect(f.status).toBe('streaming');
-    expect(f.content).toBe('looked it up');
-    const parts = f.metadata.parts as AnyPart[];
-    expect(parts).toContainEqual({ type: 'text', text: 'looked it up' });
-    const toolPart = parts.find((p) => p.type === 'tool-getPage');
-    expect(toolPart!.state).toBe('output-available');
-    expect(f.toolCalls).not.toBeNull();
-  });
-
-  it('completed: attaches finishReason + normalized usage + contextTokens', () => {
-    const f = flushAssistant([toolStep], '', 'completed', {
-      finishReason: 'stop',
-      usage: { inputTokens: 10, outputTokens: 5, totalTokens: 15 },
-      contextTokens: 15,
+  it('records an empty turn with the error text (preserves old behavior)', () => {
+    const rec = buildPartialAssistantRecord(
+      [],
+      '',
+      'error',
+      '401: Unauthorized',
+    );
+    expect(rec).toEqual({
+      text: '',
+      toolCalls: null,
+      metadata: {
+        finishReason: 'error',
+        parts: [],
+        error: '401: Unauthorized',
+      },
     });
-    expect(f.status).toBe('completed');
-    expect(f.metadata.finishReason).toBe('stop');
-    expect(f.metadata.usage).toEqual({
-      inputTokens: 10,
-      outputTokens: 5,
-      totalTokens: 15,
-      reasoningTokens: undefined,
-    });
-    expect(f.metadata.contextTokens).toBe(15);
   });
 
-  it('error: records the error and a derived finishReason', () => {
-    const f = flushAssistant([], 'partial answer', 'error', { error: 'boom' });
-    expect(f.status).toBe('error');
-    expect(f.content).toBe('partial answer');
-    expect(f.metadata.error).toBe('boom');
-    // Derives finishReason from the terminal status when none is supplied.
-    expect(f.metadata.finishReason).toBe('error');
-    expect(f.metadata.parts).toEqual([
+  it('persists in-progress text (no finished steps) as the partial answer', () => {
+    const rec = buildPartialAssistantRecord(
+      [],
+      'partial answer',
+      'error',
+      'boom',
+    );
+    expect(rec.text).toBe('partial answer');
+    expect(rec.metadata.parts).toEqual([
       { type: 'text', text: 'partial answer' },
     ]);
+    expect(rec.metadata.error).toBe('boom');
   });
 
-  it('aborted: in-progress text appended last, no error key', () => {
-    const f = flushAssistant([toolStep], ' and then', 'aborted');
-    expect(f.status).toBe('aborted');
-    expect(f.metadata.finishReason).toBe('aborted');
-    expect('error' in f.metadata).toBe(false);
-    expect(f.content).toBe('looked it up and then');
-    const parts = f.metadata.parts as AnyPart[];
-    expect(parts[parts.length - 1]).toEqual({
-      type: 'text',
-      text: ' and then',
-    });
-  });
-
-  it('combines a finished tool step with trailing in-progress text (error path)', () => {
-    // The error path captures the PARTIAL answer the user already saw: each
-    // finished step's text + tool parts, then the in-progress step's text last.
-    const flushed = flushAssistant([toolStep], ' and then', 'error', {
-      error: 'boom',
-    });
-    const parts = flushed.metadata.parts as AnyPart[];
+  it('combines a finished tool step with trailing in-progress text', () => {
+    const steps = [
+      {
+        text: 'looked it up',
+        toolCalls: [
+          { toolCallId: 'c1', toolName: 'getPage', input: { id: 'p1' } },
+        ],
+        toolResults: [
+          { toolCallId: 'c1', toolName: 'getPage', output: { title: 'T' } },
+        ],
+      },
+    ];
+    const rec = buildPartialAssistantRecord(
+      steps,
+      ' and then',
+      'error',
+      'boom',
+    );
+    const parts = rec.metadata.parts as AnyPart[];
+    // The finished step's text part is present.
     expect(parts).toContainEqual({ type: 'text', text: 'looked it up' });
+    // The paired tool call+result becomes an output-available part.
     const toolPart = parts.find((p) => p.type === 'tool-getPage');
+    expect(toolPart).toBeDefined();
     expect(toolPart!.state).toBe('output-available');
-    // In-progress text appended LAST so the parts match the stream order.
+    // The in-progress text is appended LAST so the parts match the stream order.
     expect(parts[parts.length - 1]).toEqual({
       type: 'text',
       text: ' and then',
     });
-    expect(flushed.content).toBe('looked it up and then');
-    expect(flushed.toolCalls).not.toBeNull();
-    expect(flushed.metadata.error).toBe('boom');
+    expect(rec.text).toBe('looked it up and then');
+    expect(rec.toolCalls).not.toBeNull();
+    expect(rec.metadata.error).toBe('boom');
+  });
+
+  it('omits the error key on the abort path (no errorText)', () => {
+    const rec = buildPartialAssistantRecord([], 'half', 'aborted');
+    expect(rec.metadata.finishReason).toBe('aborted');
+    expect('error' in rec.metadata).toBe(false);
+    expect(rec.text).toBe('half');
   });
 });
 
@@ -487,3 +484,143 @@ describe('accumulateStepUsage', () => {
     });
   });
 });
+
+/**
+ * Contract test for the #180 wiring in AiChatService.handle: the external MCP
+ * toolset must be built BEFORE the system prompt, and its per-server guidance
+ * threaded into buildSystemPrompt({ mcpInstructions }). The full streaming
+ * handle() is not unit-testable, so this reproduces the exact prompt-build call
+ * the service makes with a connected-server toolset and asserts the guidance is
+ * present. The toolsFor->buildSystemPrompt ordering is additionally enforced at
+ * compile time (the prompt input now consumes external.instructions).
+ */
+describe('AiChatService system prompt wiring (#180)', () => {
+  const workspace = { name: 'Acme' } as unknown as Workspace;
+
+  it('includes the external MCP server instructions in the built system prompt', () => {
+    // Shape returned by mcpClients.toolsFor (only `instructions` matters here).
+    const external: Pick<
+      Awaited<ReturnType<McpClientsService['toolsFor']>>,
+      'instructions'
+    > = {
+      instructions: [
+        {
+          serverName: 'Tavily',
+          toolPrefix: 'tavily',
+          instructions: 'Prefer tavily_search for current events.',
+        },
+      ],
+    };
+
+    // Exactly the call the service makes after building the external toolset.
+    const system = buildSystemPrompt({
+      workspace,
+      adminPrompt: 'persona',
+      mcpInstructions: external.instructions,
+    });
+
+    expect(system).toContain('<mcp_tooling');
+    expect(system).toContain('Tavily');
+    expect(system).toContain('tavily_*');
+    expect(system).toContain('Prefer tavily_search for current events.');
+  });
+
+  it('renders no MCP block when there are no external servers (empty instructions)', () => {
+    const system = buildSystemPrompt({
+      workspace,
+      adminPrompt: 'persona',
+      mcpInstructions: [],
+    });
+    expect(system).not.toContain('<mcp_tooling');
+  });
+});
+
+/**
+ * resolveOpenPageContext: the open page the client sends is attacker-controllable
+ * (id AND title), so the service must validate the id against the DB and take the
+ * title from the DB row — never echo the client title (#159, AI edits the wrong
+ * page). Built with Object.create so the test exercises the real method without
+ * the service's full dependency graph (the constructor only assigns fields).
+ */
+describe('AiChatService.resolveOpenPageContext (#159 current-page validation)', () => {
+  const ws = { id: 'ws-1' } as Workspace;
+  const user = { id: 'u-1' } as any;
+
+  function makeService(opts: {
+    page?: { id: string; workspaceId: string; title: string | null } | null;
+    canView?: boolean | 'throw-other';
+  }) {
+    const svc = Object.create(AiChatService.prototype) as AiChatService;
+    (svc as any).logger = { warn: () => {} };
+    (svc as any).pageRepo = {
+      findById: async () => opts.page ?? undefined,
+    };
+    (svc as any).pageAccess = {
+      validateCanView: async () => {
+        if (opts.canView === 'throw-other') throw new Error('db down');
+        if (opts.canView === false) throw new ForbiddenException();
+        return true;
+      },
+    };
+    return svc;
+  }
+
+  const call = (svc: AiChatService, openPage: any) =>
+    (svc as any).resolveOpenPageContext(openPage, ws, user) as Promise<{
+      id: string;
+      title: string;
+    } | null>;
+
+  it('returns null when no page is open (no id)', async () => {
+    const svc = makeService({});
+    expect(await call(svc, null)).toBeNull();
+    expect(await call(svc, {})).toBeNull();
+    expect(await call(svc, { title: 'spoofed' })).toBeNull();
+  });
+
+  it('returns null when the page does not exist', async () => {
+    const svc = makeService({ page: null });
+    expect(await call(svc, { id: 'p-x' })).toBeNull();
+  });
+
+  it('returns null for a page in a DIFFERENT workspace (tenant isolation)', async () => {
+    const svc = makeService({
+      page: { id: 'p-1', workspaceId: 'ws-OTHER', title: 'Secret' },
+    });
+    expect(await call(svc, { id: 'p-1' })).toBeNull();
+  });
+
+  it('returns null when the user may not view the page (Forbidden)', async () => {
+    const svc = makeService({
+      page: { id: 'p-1', workspaceId: 'ws-1', title: 'Restricted' },
+      canView: false,
+    });
+    expect(await call(svc, { id: 'p-1' })).toBeNull();
+  });
+
+  it('returns null (fail-closed) on a non-Forbidden access-check fault', async () => {
+    const svc = makeService({
+      page: { id: 'p-1', workspaceId: 'ws-1', title: 'X' },
+      canView: 'throw-other',
+    });
+    expect(await call(svc, { id: 'p-1' })).toBeNull();
+  });
+
+  it('uses the AUTHORITATIVE DB title, IGNORING the client-supplied title', async () => {
+    const svc = makeService({
+      page: { id: 'p-1', workspaceId: 'ws-1', title: 'Real Title B' },
+      canView: true,
+    });
+    // The client claims it is on "Page A" but the id points at page B.
+    const result = await call(svc, { id: 'p-1', title: 'Page A' });
+    expect(result).toEqual({ id: 'p-1', title: 'Real Title B' });
+  });
+
+  it('coerces a null DB title to an empty string', async () => {
+    const svc = makeService({
+      page: { id: 'p-1', workspaceId: 'ws-1', title: null },
+      canView: true,
+    });
+    expect(await call(svc, { id: 'p-1' })).toEqual({ id: 'p-1', title: '' });
+  });
+});

apps/server/src/core/ai-chat/ai-chat.service.ts

@@ -1,9 +1,4 @@
-import {
-  ForbiddenException,
-  Injectable,
-  Logger,
-  OnModuleInit,
-} from '@nestjs/common';
+import { ForbiddenException, Injectable, Logger } from '@nestjs/common';
 import { FastifyReply } from 'fastify';
 import {
   streamText,
@@ -129,7 +124,7 @@ export interface AiChatStreamArgs {
  *                    can be rebuilt for `convertToModelMessages`.
  */
 @Injectable()
-export class AiChatService implements OnModuleInit {
+export class AiChatService {
   private readonly logger = new Logger(AiChatService.name);
 
   constructor(
@@ -144,32 +139,6 @@ export class AiChatService implements OnModuleInit {
     private readonly pageAccess: PageAccessService,
   ) {}
 
-  /**
-   * Crash-recovery sweep on server start (#183): any assistant row left in the
-   * 'streaming' state is the relic of a turn whose process died before it
-   * reached a terminal status. Flip those to 'aborted' so history/export show
-   * them settled (with whatever finished steps were already persisted) instead
-   * of perpetually "streaming". Best-effort: a sweep failure is logged but must
-   * never block server startup.
-   */
-  async onModuleInit(): Promise<void> {
-    try {
-      const swept = await this.aiChatMessageRepo.sweepStreaming();
-      if (swept > 0) {
-        this.logger.log(
-          `Startup sweep: marked ${swept} dangling 'streaming' assistant ` +
-            `message(s) as 'aborted'.`,
-        );
-      }
-    } catch (err) {
-      this.logger.warn(
-        `Startup sweep of dangling 'streaming' messages failed: ${
-          err instanceof Error ? err.message : 'unknown error'
-        }`,
-      );
-    }
-  }
-
   /**
    * Resolve the agent role that applies to this stream request, scoped to the
    * workspace and soft-delete aware. For an EXISTING chat the role is read from
@@ -216,6 +185,41 @@ export class AiChatService implements OnModuleInit {
     return this.ai.getChatModel(workspaceId, roleModelOverride(role));
   }
 
+  /**
+   * Validate the client-supplied open page and return its AUTHORITATIVE identity
+   * ({ id, title }) or null. The client controls BOTH the id and the title in the
+   * request body, so neither is trusted: the id must resolve to a real page in
+   * THIS workspace that the user may read, and the title is taken from the DB row
+   * (never the client) so the model can't be told it is "on Page A" while the id
+   * points at page B (#159). Fail-closed — any missing / foreign / inaccessible
+   * page, or any non-Forbidden access-check fault, returns null.
+   */
+  private async resolveOpenPageContext(
+    openPage: { id?: string; title?: string } | null | undefined,
+    workspace: Workspace,
+    user: User,
+  ): Promise<{ id: string; title: string } | null> {
+    const candidatePageId = openPage?.id;
+    if (!candidatePageId) return null;
+    const page = await this.pageRepo.findById(candidatePageId);
+    if (!page || page.workspaceId !== workspace.id) return null;
+    try {
+      await this.pageAccess.validateCanView(page, user);
+    } catch (e) {
+      // A ForbiddenException is the expected "user cannot read this page" case;
+      // log anything else (e.g. a DB error) so a real fault is not masked.
+      if (!(e instanceof ForbiddenException)) {
+        this.logger.warn(
+          `open page access check failed: ${
+            e instanceof Error ? e.message : 'unknown error'
+          }`,
+        );
+      }
+      return null;
+    }
+    return { id: page.id, title: page.title ?? '' };
+  }
+
   async stream({
     user,
     workspace,
@@ -236,37 +240,26 @@ export class AiChatService implements OnModuleInit {
         chatId = undefined;
       }
     }
+    // The open page the client sent is attacker-controllable — BOTH its id and
+    // its title. Resolve it ONCE against the DB (workspace-scoped + access-
+    // checked) and use the AUTHORITATIVE identity everywhere below: the system
+    // prompt context, the getCurrentPage tool, and the new-chat history origin.
+    // Previously the client title was echoed verbatim, so a navigation / two-tab
+    // desync (openPage.id -> page B, title -> "Page A") made the model report
+    // "updated Page A" while it edited page B (#159). Null when no page is open
+    // or the page is foreign / inaccessible / missing.
+    const openPageContext = await this.resolveOpenPageContext(
+      body.openPage,
+      workspace,
+      user,
+    );
+
     if (!chatId) {
-      // Resolve the origin document for the history list. body.openPage.id is
-      // attacker-controllable, so validate it before persisting: it must be a
-      // real page in THIS workspace that the user is allowed to read. Anything
-      // else (foreign workspace, inaccessible/restricted, or non-existent) is
-      // dropped to null — persisting it would leak the page's title via the
-      // chat-list join, or violate the page_id FK on insert (this runs after
-      // res.hijack(), so a DB error would break the stream).
-      let originPageId: string | null = null;
-      const candidatePageId = body.openPage?.id;
-      if (candidatePageId) {
-        const page = await this.pageRepo.findById(candidatePageId);
-        if (page && page.workspaceId === workspace.id) {
-          try {
-            await this.pageAccess.validateCanView(page, user);
-            originPageId = page.id;
-          } catch (e) {
-            // Fail-closed: no provenance on any failure. A ForbiddenException is
-            // the expected "user cannot read this page" case; log anything else
-            // (e.g. a DB error) so a real fault is not masked as "no access".
-            if (!(e instanceof ForbiddenException)) {
-              this.logger.warn(
-                `origin page access check failed: ${
-                  e instanceof Error ? e.message : 'unknown error'
-                }`,
-              );
-            }
-            originPageId = null;
-          }
-        }
-      }
+      // The history-list origin is the validated open page (see above):
+      // persisting an unvalidated id would leak a title via the chat-list join,
+      // or violate the page_id FK on insert (this runs after res.hijack(), so a
+      // DB error would break the stream).
+      const originPageId: string | null = openPageContext?.id ?? null;
       const chat = await this.aiChatRepo.insert({
         creatorId: user.id,
         workspaceId: workspace.id,
@@ -312,38 +305,20 @@ export class AiChatService implements OnModuleInit {
     // The model is resolved by the controller before hijack (clean 503 path).
     // Here we only need the admin-configured system prompt.
     const resolved = await this.aiSettings.resolve(workspace.id);
-    const system = buildSystemPrompt({
-      workspace,
-      adminPrompt: resolved?.systemPrompt,
-      // The role (pre-resolved by the controller) REPLACES the persona layer;
-      // the safety framework is still appended by buildSystemPrompt.
-      roleInstructions: role?.instructions,
-      openedPage: body.openPage,
-    });
 
-    // Pass the resolved chatId so the write tools can mint provenance tokens
-    // (access + collab) carrying { actor:'agent', aiChatId: chatId }, making
-    // agent REST/collab writes attributable and non-spoofable (§6.5/§6.6).
-    const docmostTools = await this.tools.forUser(
-      user,
-      sessionId,
-      workspace.id,
-      chatId,
-      // Same open-page value used by the system prompt above; exposed to the
-      // model via getCurrentPage so page identity survives prompt mangling.
-      body.openPage,
-    );
-
-    // Merge in admin-configured external MCP tools (web search, etc.; §6.8).
-    // A down/slow external server never crashes the turn — toolsFor skips it and
-    // records the outcome. The returned client handles MUST be closed in the
-    // streamText lifecycle (onFinish/onError/onAbort) — leaking them is a bug.
-    // Docmost tools take precedence on a name clash (external are namespaced, so
-    // a clash is not expected; the spread order makes intent explicit).
+    // Build the external MCP toolset FIRST so the system prompt can carry each
+    // connected server's admin-authored guidance (#180). Merge in admin-
+    // configured external MCP tools (web search, etc.; §6.8). A down/slow
+    // external server never crashes the turn — toolsFor skips it and records the
+    // outcome. The returned client handles MUST be closed in the streamText
+    // lifecycle (onFinish/onError/onAbort) — leaking them is a bug. Docmost
+    // tools take precedence on a name clash (external are namespaced, so a clash
+    // is not expected; the spread order makes intent explicit).
     let external: Awaited<ReturnType<McpClientsService['toolsFor']>> = {
       tools: {},
       clients: [],
       outcomes: [],
+      instructions: [],
     };
     try {
       external = await this.mcpClients.toolsFor(workspace.id);
@@ -356,6 +331,33 @@ export class AiChatService implements OnModuleInit {
         }`,
       );
     }
+
+    const system = buildSystemPrompt({
+      workspace,
+      adminPrompt: resolved?.systemPrompt,
+      // The role (pre-resolved by the controller) REPLACES the persona layer;
+      // the safety framework is still appended by buildSystemPrompt.
+      roleInstructions: role?.instructions,
+      // Server-validated open page (authoritative title), not the client value.
+      openedPage: openPageContext,
+      // Guidance only for servers that connected and yielded ≥1 callable tool.
+      mcpInstructions: external.instructions,
+    });
+
+    // Pass the resolved chatId so the write tools can mint provenance tokens
+    // (access + collab) carrying { actor:'agent', aiChatId: chatId }, making
+    // agent REST/collab writes attributable and non-spoofable (§6.5/§6.6).
+    const docmostTools = await this.tools.forUser(
+      user,
+      sessionId,
+      workspace.id,
+      chatId,
+      // Same server-validated open page used by the system prompt above; exposed
+      // to the model via getCurrentPage so page identity (and the AUTHORITATIVE
+      // title) survives prompt mangling and client title spoofing (#159).
+      openPageContext,
+    );
+
     const tools = { ...external.tools, ...docmostTools };
 
     // Close every external client EXACTLY ONCE across the turn's terminal
@@ -379,6 +381,31 @@ export class AiChatService implements OnModuleInit {
       );
     };
 
+    // Persist the assistant message. Used by onFinish (full result) and the
+    // abort/error paths (partial result). Guarded so we persist at most once.
+    let persisted = false;
+    const persistAssistant = async (data: {
+      text: string;
+      toolCalls: unknown;
+      metadata: Record<string, unknown>;
+    }): Promise<void> => {
+      if (persisted) return;
+      persisted = true;
+      try {
+        await this.aiChatMessageRepo.insert({
+          chatId,
+          workspaceId: workspace.id,
+          userId: user.id,
+          role: 'assistant',
+          content: data.text ?? '',
+          toolCalls: (data.toolCalls ?? null) as never,
+          metadata: data.metadata as never,
+        });
+      } catch (err) {
+        this.logger.error('Failed to persist assistant message', err as Error);
+      }
+    };
+
     // Accumulate the turn's streamed output so a provider error / disconnect can
     // persist the PARTIAL answer the user already saw — the SDK's onError/onAbort
     // callbacks don't hand us the in-progress text. `capturedSteps` holds finished
@@ -387,101 +414,6 @@ export class AiChatService implements OnModuleInit {
     const capturedSteps: StepLike[] = [];
     let inProgressText = '';
 
-    // Step-granular durability (#183): create the assistant row UPFRONT in the
-    // 'streaming' state (before any token), then UPDATE it as each step finishes
-    // and finalize it once on the terminal callback. If the process dies
-    // mid-turn the row survives with every finished step already persisted; the
-    // startup sweep (sweepStreaming) later flips a dangling 'streaming' row to
-    // 'aborted'. The DB is now the single source of truth for the turn — the
-    // socket is never required for the write path. A failed upfront insert is
-    // logged and leaves assistantId undefined; the per-step/terminal updates then
-    // no-op (guarded below) so the turn still streams to the user.
-    let assistantId: string | undefined;
-    try {
-      const seed = flushAssistant([], '', 'streaming');
-      const seeded = await this.aiChatMessageRepo.insert({
-        chatId,
-        workspaceId: workspace.id,
-        userId: user.id,
-        role: 'assistant',
-        content: seed.content,
-        // jsonb columns: cast through never (same as the user insert above).
-        toolCalls: (seed.toolCalls ?? null) as never,
-        metadata: seed.metadata as never,
-        status: seed.status,
-      });
-      assistantId = seeded?.id;
-    } catch (err) {
-      this.logger.error(
-        `Failed to insert upfront assistant row (chat ${chatId}, workspace ${workspace.id})`,
-        err as Error,
-      );
-    }
-
-    // Per-step (non-terminal) update: persist the finished steps the moment a
-    // step ends. Tolerant — a failed update is logged and swallowed so it never
-    // throws into the stream. Keeps status 'streaming'.
-    const updateStreaming = async (): Promise<void> => {
-      if (!assistantId) return;
-      // Cheap short-circuit once the turn is finalized (see `finalized` below).
-      // The AUTHORITATIVE guard is `onlyIfStreaming` on the UPDATE: a late
-      // fire-and-forget step update could still be in flight on another pool
-      // connection when finalize runs, so the SQL `WHERE status='streaming'`
-      // (not this flag) is what prevents it clobbering the terminal row.
-      if (finalized) return;
-      try {
-        await this.aiChatMessageRepo.update(
-          assistantId,
-          workspace.id,
-          flushAssistant(capturedSteps, '', 'streaming'),
-          { onlyIfStreaming: true },
-        );
-      } catch (err) {
-        this.logger.warn(
-          `Failed to update streaming assistant row: ${
-            err instanceof Error ? err.message : 'unknown error'
-          }`,
-        );
-      }
-    };
-
-    // Serialize the per-step updates (#183 review): onStepFinish fires them
-    // without await, so two could otherwise commit out of order on different pool
-    // connections (step N landing after N+1). Chaining each onto the previous
-    // keeps the persisted row monotonic with step order; each link short-circuits
-    // on `finalized`, so a tail of late updates is cheap.
-    let stepUpdateChain: Promise<void> = Promise.resolve();
-
-    // Terminal finalize: write the completed/error/aborted row exactly once
-    // across the (mutually-exclusive, at-most-once) onFinish/onError/onAbort
-    // callbacks — mirroring the pre-#183 persist-at-most-once guard for the
-    // TERMINAL status (the row may be updated many times with 'streaming' before
-    // this fires once).
-    let finalized = false;
-    const finalizeAssistant = async (
-      flushed: AssistantFlush,
-    ): Promise<void> => {
-      if (finalized) return;
-      finalized = true;
-      const plan = planFinalizeAssistant(assistantId);
-      try {
-        // Shared dispatch (see applyFinalize): UPDATE the upfront row, or — when
-        // the upfront insert failed (kind 'insert') — INSERT the terminal row as
-        // the only safety against losing the turn entirely.
-        await applyFinalize(
-          this.aiChatMessageRepo,
-          plan,
-          { chatId, workspaceId: workspace.id, userId: user.id },
-          flushed,
-        );
-      } catch (err) {
-        this.logger.error(
-          `Failed to finalize assistant message (kind=${plan.kind})`,
-          err as Error,
-        );
-      }
-    };
-
     // DIAGNOSTIC (Safari stream-drop investigation) — temporary. Measure
     // first-chunk latency, the model-silent gap right before a disconnect, and
     // how many SSE heartbeats were written, so a Safari drop can be classified
@@ -530,12 +462,6 @@ export class AiChatService implements OnModuleInit {
           // the in-progress accumulator for the next step.
           capturedSteps.push(step as StepLike);
           inProgressText = '';
-          // Step-granular durability (#183): persist this finished step (its text +
-          // tool calls + tool RESULTS) the moment it ends, so a process death after
-          // this point still recovers the step. Not awaited here (never block the
-          // stream), but SERIALIZED via stepUpdateChain so the writes commit in
-          // step order; updateStreaming is error-tolerant (logs + swallows).
-          stepUpdateChain = stepUpdateChain.then(() => updateStreaming());
         },
         onFinish: async ({ text, finishReason, totalUsage, usage, steps }) => {
           // DIAGNOSTIC (Safari stream-drop investigation) — temporary: success
@@ -546,31 +472,30 @@ export class AiChatService implements OnModuleInit {
               `firstChunkLatency=${firstModelChunkAt ? firstModelChunkAt - streamStartedAt : 'none'}ms ` +
               `heartbeatsSent=${heartbeatsSent} steps=${steps.length}`,
           );
-          // Finalize the assistant row (#183): the upfront 'streaming' row is
-          // UPDATEd to 'completed' with the turn's final text, cumulative usage and
-          // full UIMessage parts. We pass the SDK `steps` (which carry the final
-          // step's text) as the captured steps so metadata.parts matches the
-          // pre-#183 onFinish record exactly; `inProgressText` is '' here (the last
-          // step already finished). Final-step usage (usage.input+output) ≈ the
-          // conversation's CURRENT context size, distinct from totalUsage.
-          //
-          // COLUMN-SEMANTICS NOTE (#183): `content` is built by flushAssistant as
-          // the CONCATENATION of every step's text (stepsText), whereas pre-#183
-          // it stored only the FINAL step's text. This is a deliberate, harmless
-          // change: the UI and the Markdown export render from `metadata.parts`
-          // (per-step text + tool parts), not from `content`; `content` is the
-          // plain-text projection (full-text search / fallback). A multi-step
-          // turn's `content` therefore now holds all steps' prose, not just the
-          // last block.
-          await finalizeAssistant(
-            flushAssistant(steps as StepLike[], '', 'completed', {
-              finishReason: finishReason as string,
-              usage: totalUsage as StreamUsage,
+          await persistAssistant({
+            text,
+            toolCalls: serializeSteps(steps),
+            metadata: {
+              finishReason,
+              // Persist the turn's cumulative usage WITH reasoning tokens resolved
+              // from either the new `outputTokenDetails` or the deprecated top-level
+              // field, so reopened history / the Markdown export show the thinking
+              // token cost too.
+              usage:
+                normalizeStreamUsage(totalUsage as StreamUsage) ?? totalUsage,
+              // Final-step usage = the context actually fed to the model on the last LLM
+              // call (full history + tool results) plus the answer it just generated.
+              // input+output of the FINAL step ≈ the conversation's CURRENT context size,
+              // distinct from totalUsage which sums every step (cumulative tokens spent).
               contextTokens:
                 (usage?.inputTokens ?? 0) + (usage?.outputTokens ?? 0) ||
                 undefined,
-            }),
-          );
+              // Persist the FULL set of UIMessage parts for the turn (text +
+              // tool-call/result), so the rebuilt history replays prior tool
+              // context to the model on later turns.
+              parts: assistantParts(steps, text),
+            },
+          });
           // Lifecycle: release the external MCP clients leased for this turn.
           await closeExternalClients();
 
@@ -606,14 +531,16 @@ export class AiChatService implements OnModuleInit {
               `firstChunkLatency=${firstModelChunkAt ? firstModelChunkAt - streamStartedAt : 'none'}ms ` +
               `silentGapBeforeDrop=${diagNow - lastModelChunkAt}ms heartbeatsSent=${heartbeatsSent}`,
           );
-          // Finalize the PARTIAL answer streamed before the failure (text + any
+          // Persist the PARTIAL answer streamed before the failure (text + any
           // finished tool steps) WITH the error in metadata, so the turn shows what
-          // the user already saw plus the cause — not just a bare error. Status
-          // 'error' (#183).
-          await finalizeAssistant(
-            flushAssistant(capturedSteps, inProgressText, 'error', {
-              error: errorText,
-            }),
+          // the user already saw plus the cause — not just a bare error.
+          await persistAssistant(
+            buildPartialAssistantRecord(
+              capturedSteps,
+              inProgressText,
+              'error',
+              errorText,
+            ),
           );
           await closeExternalClients();
         },
@@ -637,8 +564,12 @@ export class AiChatService implements OnModuleInit {
               `silentGapBeforeDrop=${diagNow - lastModelChunkAt}ms heartbeatsSent=${heartbeatsSent} ` +
               `steps=${steps.length}`,
           );
-          await finalizeAssistant(
-            flushAssistant(capturedSteps, inProgressText, 'aborted'),
+          await persistAssistant(
+            buildPartialAssistantRecord(
+              capturedSteps,
+              inProgressText,
+              'aborted',
+            ),
           );
           await closeExternalClients();
         },
@@ -1087,132 +1018,38 @@ export function rowToUiMessage(row: AiChatMessage): Omit<UIMessage, 'id'> & {
 }
 
 /**
- * The persisted-row patch shape produced by {@link flushAssistant}. It is the
- * SAME shape the assistant repo insert/update consume (content + toolCalls +
- * metadata) plus the lifecycle `status` column added in #183.
+ * Build the assistant-message record persisted on a partial/failed turn (the
+ * streamText onError / onAbort paths). Captures the partial answer the user
+ * already saw: each finished step's text + tool parts (via assistantParts),
+ * then the in-progress step's text appended last. When `errorText` is provided
+ * it is recorded in metadata.error so the cause shows in history; an aborted
+ * turn passes none. Pure, so the partial-recording shape is unit-testable
+ * without seaming streamText.
  */
-export interface AssistantFlush {
-  content: string;
-  toolCalls: unknown;
-  metadata: Record<string, unknown>;
-  status: 'streaming' | 'completed' | 'error' | 'aborted';
-}
-
-/**
- * Pure decision for the terminal finalize (#183): given whether the upfront
- * assistant row exists (`assistantId`), choose whether the terminal payload is
- * written by UPDATEing that row or — when the upfront insert failed and there is
- * no id — by INSERTing a fresh terminal row so the turn is not lost entirely.
- * Returns `{ kind: 'update', id }` or `{ kind: 'insert' }`. Extracted so the
- * fallback-insert branch (the only safety against losing a turn whose upfront
- * insert failed) is unit-testable without seaming streamText.
- */
-export function planFinalizeAssistant(
-  assistantId: string | undefined,
-): { kind: 'update'; id: string } | { kind: 'insert' } {
-  return assistantId ? { kind: 'update', id: assistantId } : { kind: 'insert' };
-}
-
-/** The repo surface the terminal finalize needs (structural — the real repo and
- *  a test mock both satisfy it). */
-export interface FinalizeRepo {
-  insert(insertable: Record<string, unknown>): Promise<unknown>;
-  update(
-    id: string,
-    workspaceId: string,
-    patch: AssistantFlush,
-  ): Promise<unknown>;
-}
-
-/**
- * Apply a finalize `plan` to the repo with the terminal `flushed` payload (#183):
- * UPDATE the upfront row, or INSERT a fresh terminal row as the fallback when the
- * upfront insert failed. The SINGLE dispatch shared by the service's
- * finalizeAssistant and its test, so the test exercises the real path instead of
- * a copy (#186 review). Pure of error handling — the caller wraps it.
- */
-export async function applyFinalize(
-  repo: FinalizeRepo,
-  plan: { kind: 'update'; id: string } | { kind: 'insert' },
-  base: { chatId: string; workspaceId: string; userId: string },
-  flushed: AssistantFlush,
-): Promise<void> {
-  if (plan.kind === 'update') {
-    await repo.update(plan.id, base.workspaceId, flushed);
-    return;
-  }
-  await repo.insert({
-    chatId: base.chatId,
-    workspaceId: base.workspaceId,
-    userId: base.userId,
-    role: 'assistant',
-    content: flushed.content,
-    toolCalls: flushed.toolCalls ?? null,
-    metadata: flushed.metadata,
-    status: flushed.status,
-  });
-}
-
-/**
- * PURE assistant-row builder (#183 step-granular durability). Given the turn's
- * accumulated steps + the in-progress (not-yet-finished) text + the lifecycle
- * status, it returns the row patch to persist. The SAME path runs for the
- * upfront insert (empty steps, status 'streaming'), every per-step update, and
- * the terminal finalize (completed/error/aborted) — and a future background
- * worker can call it identically, so it must stay a pure function of its inputs
- * (NO `this`, no IO).
- *
- * `metadata.parts` is built by assistantParts over the finished steps, then the
- * in-progress text appended as a trailing text part, so rowToUiMessage /
- * findRecent keep replaying the turn unchanged. `metadata.finishReason`,
- * `metadata.error`, `metadata.usage` and `metadata.contextTokens` are attached
- * only when provided/relevant, matching the pre-#183 onFinish/onError records.
- */
-export function flushAssistant(
-  capturedSteps: ReadonlyArray<StepLike> | undefined,
+export function buildPartialAssistantRecord(
+  steps: ReadonlyArray<StepLike> | undefined,
   inProgressText: string,
-  status: 'streaming' | 'completed' | 'error' | 'aborted',
-  extra?: {
-    finishReason?: string;
-    usage?: ChatStreamUsage | StreamUsage | undefined;
-    contextTokens?: number;
-    error?: string;
-  },
-): AssistantFlush {
-  const finished = capturedSteps ?? [];
+  finishReason: 'error' | 'aborted',
+  errorText?: string,
+): { text: string; toolCalls: unknown; metadata: Record<string, unknown> } {
+  const finished = steps ?? [];
   const stepsText = finished.map((s) => s.text ?? '').join('');
   const trailing = inProgressText ?? '';
   // assistantParts emits text parts only for FINISHED steps; append the
-  // in-progress step's text (the partial answer cut off by an error/abort, or
-  // simply not yet flushed mid-stream) as the last text part so the persisted
-  // parts match what streamed to the client.
+  // in-progress step's text (the answer cut off by the error) as the last text
+  // part so the persisted parts match what streamed to the client.
   const parts = assistantParts(finished, '') as unknown as Array<
     Record<string, unknown>
   >;
   if (trailing) parts.push({ type: 'text', text: trailing });
-
-  const metadata: Record<string, unknown> = {
-    parts: parts as unknown as UIMessage['parts'],
-  };
-  // finishReason: prefer an explicit one; else derive a sensible value from the
-  // terminal status (so onError/onAbort records keep their historical reason).
-  if (extra?.finishReason) {
-    metadata.finishReason = extra.finishReason;
-  } else if (status === 'error' || status === 'aborted') {
-    metadata.finishReason = status;
-  }
-  if (extra?.usage !== undefined) {
-    metadata.usage =
-      normalizeStreamUsage(extra.usage as StreamUsage) ?? extra.usage;
-  }
-  if (extra?.contextTokens) metadata.contextTokens = extra.contextTokens;
-  if (extra?.error) metadata.error = extra.error;
-
   return {
-    content: stepsText + trailing,
+    text: stepsText + trailing,
     toolCalls: serializeSteps(finished),
-    metadata,
-    status,
+    metadata: {
+      finishReason,
+      parts: parts as unknown as UIMessage['parts'],
+      ...(errorText ? { error: errorText } : {}),
+    },
   };
 }
 

apps/server/src/core/ai-chat/chat-markdown.util.spec.ts

@@ -1,295 +0,0 @@
-import { buildChatMarkdown, normalizeLang } from './chat-markdown.util';
-import type { AiChatMessage } from '@docmost/db/types/entity.types';
-
-/**
- * normalizeLang: the client sends `i18n.language` — a FULL locale tag like
- * 'en-US' / 'ru-RU', NOT a bare 'en'/'ru'. A `@IsIn(['en','ru'])` DTO rejected
- * that with a 400 (caught in real-browser testing); the export now accepts any
- * string and normalizes here. Guards that regression.
- */
-describe('normalizeLang', () => {
-  it("maps any 'ru…' locale tag to ru", () => {
-    expect(normalizeLang('ru')).toBe('ru');
-    expect(normalizeLang('ru-RU')).toBe('ru');
-    expect(normalizeLang('RU-ru')).toBe('ru');
-  });
-
-  it('maps everything else (incl. region-qualified English) to en', () => {
-    expect(normalizeLang('en')).toBe('en');
-    expect(normalizeLang('en-US')).toBe('en');
-    expect(normalizeLang('fr-FR')).toBe('en');
-    expect(normalizeLang(undefined)).toBe('en');
-    expect(normalizeLang('')).toBe('en');
-  });
-});
-
-/**
- * Unit tests for the SERVER Markdown export (#183). Mirrors the coverage of the
- * (now-removed) client chat-markdown tests: heading/metadata, role labels, text
- * + tool blocks, token footers, the interrupted-turn note, and NULL-status
- * (legacy) rows. The export embeds a live `new Date().toISOString()` timestamp;
- * we never assert it, only the deterministic structure.
- */
-
-function row(partial: Partial<AiChatMessage>): AiChatMessage {
-  return {
-    id: partial.id ?? 'id',
-    chatId: partial.chatId ?? 'chat-1',
-    workspaceId: partial.workspaceId ?? 'ws-1',
-    userId: partial.userId ?? null,
-    role: partial.role ?? 'user',
-    content: partial.content ?? null,
-    toolCalls: partial.toolCalls ?? null,
-    metadata: partial.metadata ?? null,
-    status: partial.status ?? null,
-    createdAt: partial.createdAt ?? ('2026-06-21T00:00:00.000Z' as never),
-    updatedAt: partial.updatedAt ?? ('2026-06-21T00:00:00.000Z' as never),
-    deletedAt: partial.deletedAt ?? null,
-  } as AiChatMessage;
-}
-
-describe('buildChatMarkdown (server) — structure', () => {
-  it('emits the title heading, chat id and message count', () => {
-    const md = buildChatMarkdown({
-      title: 'My chat',
-      chatId: 'chat-123',
-      rows: [],
-    });
-    expect(md).toContain('# My chat');
-    expect(md).toContain('- Chat ID: `chat-123`');
-    expect(md).toContain('- Messages: 0');
-  });
-
-  it('falls back to "Untitled chat" with no title (en)', () => {
-    const md = buildChatMarkdown({ title: null, chatId: 'c', rows: [] });
-    expect(md).toContain('# Untitled chat');
-  });
-
-  it('localizes fixed labels with lang=ru (structure stays English)', () => {
-    const md = buildChatMarkdown({
-      title: null,
-      chatId: 'c',
-      lang: 'ru',
-      rows: [row({ role: 'assistant', content: 'hi' })],
-    });
-    expect(md).toContain('# Без названия');
-    expect(md).toContain('## 1. ИИ-агент');
-    // Structural words remain English.
-    expect(md).toContain('- Chat ID:');
-  });
-
-  it('numbers messages and labels roles (You / AI agent)', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({ role: 'user', content: 'question' }),
-        row({ role: 'assistant', content: 'answer' }),
-      ],
-    });
-    expect(md).toContain('## 1. You');
-    expect(md).toContain('question');
-    expect(md).toContain('## 2. AI agent');
-    expect(md).toContain('answer');
-  });
-
-  it('renders a tool part with fenced input/output and the friendly label', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({
-          role: 'assistant',
-          content: 'done',
-          metadata: {
-            parts: [
-              {
-                type: 'tool-getPage',
-                state: 'output-available',
-                input: { id: 'p1' },
-                output: { title: 'Hello' },
-              },
-              { type: 'text', text: 'done' },
-            ],
-          } as never,
-        }),
-      ],
-    });
-    expect(md).toContain('**Tool: Read page** (`getPage`) — done');
-    expect(md).toContain('Input:');
-    expect(md).toContain('"id": "p1"');
-    expect(md).toContain('Output:');
-    expect(md).toContain('"title": "Hello"');
-  });
-
-  // #186 re-review pt 1: restore the parity coverage of the removed client spec —
-  // error state, unknown-tool fallback (en + ru), and the circular-stringify catch.
-  it('renders a tool part in the error state with its errorText', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({
-          role: 'assistant',
-          metadata: {
-            parts: [
-              {
-                type: 'tool-getPage',
-                state: 'output-error',
-                input: { id: 'p1' },
-                errorText: 'page not found',
-              },
-            ],
-          } as never,
-        }),
-      ],
-    });
-    expect(md).toContain('**Tool: Read page** (`getPage`) — error');
-    expect(md).toContain('**Error:** page not found');
-  });
-
-  it('falls back to "Ran tool <name>" for an unknown tool (en) and the ru variant', () => {
-    const parts = [
-      {
-        type: 'tool-mysteryTool',
-        state: 'output-available',
-        output: { ok: 1 },
-      },
-    ];
-    const en = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [row({ role: 'assistant', metadata: { parts } as never })],
-    });
-    expect(en).toContain('**Tool: Ran tool mysteryTool** (`mysteryTool`)');
-    const ru = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      lang: 'ru',
-      rows: [row({ role: 'assistant', metadata: { parts } as never })],
-    });
-    expect(ru).toContain('Выполнил инструмент mysteryTool');
-  });
-
-  it('does not throw on a circular tool output (falls back to String)', () => {
-    const circular: Record<string, unknown> = {};
-    circular.self = circular;
-    expect(() =>
-      buildChatMarkdown({
-        title: 'T',
-        chatId: 'c',
-        rows: [
-          row({
-            role: 'assistant',
-            metadata: {
-              parts: [
-                {
-                  type: 'tool-getPage',
-                  state: 'output-available',
-                  output: circular,
-                },
-              ],
-            } as never,
-          }),
-        ],
-      }),
-    ).not.toThrow();
-  });
-
-  it('emits a token footer + total when usage is present', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({
-          role: 'assistant',
-          content: 'a',
-          metadata: {
-            usage: {
-              inputTokens: 100,
-              outputTokens: 20,
-              totalTokens: 120,
-              reasoningTokens: 8,
-            },
-          } as never,
-        }),
-      ],
-    });
-    expect(md).toContain('- Total tokens: 120');
-    expect(md).toContain(
-      '_Tokens — in: 100, out: 20, reasoning: 8, total: 120_',
-    );
-  });
-
-  it('flags a still-streaming (interrupted) row', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({ role: 'assistant', content: 'partial', status: 'streaming' }),
-      ],
-    });
-    expect(md).toContain('still being generated');
-  });
-
-  it('does NOT flag a completed row', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [row({ role: 'assistant', content: 'final', status: 'completed' })],
-    });
-    expect(md).not.toContain('still being generated');
-  });
-
-  it('renders a legacy NULL-status row (no parts) from plain content', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({ role: 'assistant', content: 'legacy answer', status: null }),
-      ],
-    });
-    expect(md).toContain('legacy answer');
-    expect(md).not.toContain('still being generated');
-  });
-
-  it('renders a persisted error', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({
-          role: 'assistant',
-          content: '',
-          status: 'error',
-          metadata: { error: '401: Unauthorized' } as never,
-        }),
-      ],
-    });
-    expect(md).toContain('**⚠️ Error:** 401: Unauthorized');
-  });
-
-  it('escapes embedded triple-backtick fences with a longer delimiter', () => {
-    const md = buildChatMarkdown({
-      title: 'T',
-      chatId: 'c',
-      rows: [
-        row({
-          role: 'assistant',
-          content: 'x',
-          metadata: {
-            parts: [
-              {
-                type: 'tool-getPage',
-                state: 'output-available',
-                output: '```inner```',
-              },
-            ],
-          } as never,
-        }),
-      ],
-    });
-    // A 4-backtick fence wraps content that itself contains a 3-backtick run.
-    expect(md).toContain('````');
-  });
-});

apps/server/src/core/ai-chat/chat-markdown.util.ts

@@ -1,299 +0,0 @@
-/**
- * Server-side Markdown export for an AI agent chat (#183). The DB is the single
- * source of truth: this renders a chat purely from its persisted message rows
- * (`AiChatMessage[]` — role / content / metadata.parts / toolCalls / usage).
- * Because the assistant row is now persisted UPFRONT and updated per step, an
- * interrupted turn is included up to its last finished step.
- *
- * Ported from the client `utils/chat-markdown.ts`. It is a PURE function (apart
- * from `new Date()` for the export timestamp), so it is straightforward to
- * unit-test and a future background worker can reuse it.
- *
- * Only a few fixed role/tool labels are localized via the `lang` param; the
- * structural document words (Input/Output/Error/Tokens/...) stay English because
- * the output is a technical artifact.
- */
-
-import type { AiChatMessage } from '@docmost/db/types/entity.types';
-
-/** Supported export label languages. Defaults to English. */
-export type ExportLang = 'en' | 'ru';
-
-/**
- * Normalize an arbitrary client locale code to a supported export language. The
- * client sends `i18n.language`, which is a FULL locale tag (e.g. `en-US`,
- * `ru-RU`), not a bare `en`/`ru` — so match on the language subtag and fall back
- * to English for anything non-Russian.
- */
-export function normalizeLang(lang?: string): ExportLang {
-  return lang?.toLowerCase().startsWith('ru') ? 'ru' : 'en';
-}
-
-/** A single AI SDK UIMessage part (text part or a tool part). */
-interface ExportPart {
-  type: string;
-  text?: string;
-  state?: string;
-  toolName?: string;
-  input?: unknown;
-  output?: unknown;
-  errorText?: string;
-}
-
-/** Authoritative per-turn usage the server attaches to a message row. */
-interface UsageLike {
-  inputTokens?: number;
-  outputTokens?: number;
-  totalTokens?: number;
-  reasoningTokens?: number;
-}
-
-/** Localized label table. The client-side Markdown builder was removed by #183
- *  (the export is now server-side only), so this no longer mirrors a second
- *  exporter — instead the tool-action labels are kept in parity with the
- *  on-screen action-log labels in the client's `tool-parts.tsx` (`toolLabelKey`)
- *  so the export reads the same as the UI. Only role + tool-action labels are
- *  localized; everything structural is an English constant in the renderer. */
-const LABELS: Record<
-  ExportLang,
-  {
-    untitled: string;
-    aiAgent: string;
-    you: string;
-    tools: Record<string, string>;
-    ranTool: (name: string) => string;
-    stillGenerating: string;
-  }
-> = {
-  en: {
-    untitled: 'Untitled chat',
-    aiAgent: 'AI agent',
-    you: 'You',
-    tools: {
-      searchPages: 'Searched pages',
-      getPage: 'Read page',
-      createPage: 'Created page',
-      updatePageContent: 'Updated page',
-      renamePage: 'Renamed page',
-      movePage: 'Moved page',
-      deletePage: 'Deleted page (to trash)',
-      createComment: 'Commented',
-      resolveComment: 'Resolved comment',
-    },
-    ranTool: (name) => `Ran tool ${name}`,
-    stillGenerating:
-      'This message is still being generated — the export captured a partial, in-progress response.',
-  },
-  ru: {
-    untitled: 'Без названия',
-    aiAgent: 'ИИ-агент',
-    you: 'Вы',
-    tools: {
-      searchPages: 'Искал по страницам',
-      getPage: 'Прочитал страницу',
-      createPage: 'Создал страницу',
-      updatePageContent: 'Обновил страницу',
-      renamePage: 'Переименовал страницу',
-      movePage: 'Переместил страницу',
-      deletePage: 'Удалил страницу (в корзину)',
-      createComment: 'Прокомментировал',
-      resolveComment: 'Закрыл комментарий',
-    },
-    ranTool: (name) => `Выполнил инструмент ${name}`,
-    stillGenerating:
-      'Это сообщение всё ещё генерируется — экспорт захватил частичный, незавершённый ответ.',
-  },
-};
-
-/** True for AI SDK tool parts (static `tool-*` or `dynamic-tool`). */
-function isToolPart(type: string): boolean {
-  return type.startsWith('tool-') || type === 'dynamic-tool';
-}
-
-/** Extract the tool name from a part `type` of `tool-${name}` (or dynamic). */
-function getToolName(part: ExportPart): string {
-  if (part.type === 'dynamic-tool') return part.toolName ?? '';
-  return part.type.startsWith('tool-')
-    ? part.type.slice('tool-'.length)
-    : part.type;
-}
-
-/** Map an AI SDK tool-part state to the 3 states the action-log renders. */
-function toolRunState(state: string | undefined): 'running' | 'done' | 'error' {
-  if (state === 'output-error' || state === 'output-denied') return 'error';
-  if (state === 'output-available') return 'done';
-  return 'running';
-}
-
-/** Resolve a tool's friendly action-log label (localized) from its name. */
-function toolLabel(name: string, lang: ExportLang): string {
-  return LABELS[lang].tools[name] ?? LABELS[lang].ranTool(name);
-}
-
-/**
- * Stringify an arbitrary tool input/output value for a fenced block. Strings
- * pass through as-is; everything else is pretty-printed JSON, falling back to
- * `String(value)` if serialization throws (e.g. a circular structure).
- */
-function stringify(value: unknown): string {
-  if (typeof value === 'string') return value;
-  try {
-    return JSON.stringify(value, null, 2);
-  } catch {
-    return String(value);
-  }
-}
-
-/**
- * Wrap `code` in a fenced code block whose backtick delimiter is LONGER than the
- * longest backtick run inside the content, so embedded backticks (or a literal
- * ``` fence) never break out of the block. Minimum 3 backticks.
- */
-function fence(code: string, lang = ''): string {
-  const runs: string[] = code.match(/`+/g) ?? [];
-  const longest = runs.reduce((m, s) => Math.max(m, s.length), 0);
-  const delim = '`'.repeat(Math.max(3, longest + 1));
-  return `${delim}${lang}\n${code}\n${delim}`;
-}
-
-/** Per-row token count, mirroring the header sum in the client window. */
-function rowTokens(usage: UsageLike): number {
-  return (
-    usage.totalTokens ?? (usage.inputTokens ?? 0) + (usage.outputTokens ?? 0)
-  );
-}
-
-/** Render one message's UIMessage parts into an array of Markdown blocks
- *  (text blocks + tool blocks). Mirrors the client renderer / MessageItem. */
-function renderMessageParts(parts: ExportPart[], lang: ExportLang): string[] {
-  const out: string[] = [];
-
-  for (const part of parts) {
-    if (part.type === 'text') {
-      const text = (part.text ?? '').trim();
-      if (text.length > 0) out.push(text);
-      continue;
-    }
-
-    if (!isToolPart(part.type)) continue;
-
-    const name = getToolName(part);
-    const label = toolLabel(name, lang);
-    const state = toolRunState(part.state);
-
-    const toolLines: string[] = [`**Tool: ${label}** (\`${name}\`) — ${state}`];
-    if (part.input !== undefined) {
-      toolLines.push('Input:');
-      toolLines.push(fence(stringify(part.input), 'json'));
-    }
-    if (part.output !== undefined) {
-      toolLines.push('Output:');
-      toolLines.push(fence(stringify(part.output), 'json'));
-    }
-    if (part.errorText) {
-      toolLines.push(`**Error:** ${part.errorText}`);
-    }
-    out.push(toolLines.join('\n\n'));
-  }
-
-  return out;
-}
-
-/** Resolve a persisted row's parts: prefer the rich persisted parts, else a
- *  single text part built from the plain-text content (mirrors rowToUiMessage). */
-function rowParts(row: AiChatMessage): ExportPart[] {
-  const meta = (row.metadata ?? {}) as { parts?: ExportPart[] };
-  return Array.isArray(meta.parts) && meta.parts.length > 0
-    ? meta.parts
-    : [{ type: 'text', text: row.content ?? '' }];
-}
-
-/**
- * Serialize a chat to a Markdown string from its persisted rows. Source = DB
- * ONLY (no live client state). A row whose `status` is still 'streaming' is an
- * interrupted turn that the export captured mid-flight; it is rendered up to its
- * last finished step and flagged "still generating".
- */
-export function buildChatMarkdown(args: {
-  title: string | null;
-  chatId: string;
-  rows: AiChatMessage[];
-  // Accepts a full client locale tag (e.g. 'en-US'/'ru-RU'); normalized below.
-  lang?: string;
-}): string {
-  const { title, chatId, rows } = args;
-  const lang: ExportLang = normalizeLang(args.lang);
-  const L = LABELS[lang];
-  const blocks: string[] = [];
-
-  const heading = (title ?? '').trim() || L.untitled;
-  blocks.push(`# ${heading}`);
-
-  const usageOf = (row: AiChatMessage): UsageLike | undefined => {
-    const meta = (row.metadata ?? {}) as { usage?: UsageLike };
-    return meta.usage;
-  };
-  const errorOf = (row: AiChatMessage): string | undefined => {
-    const meta = (row.metadata ?? {}) as { error?: string };
-    return meta.error;
-  };
-
-  // Metadata bullet list. Total tokens is only shown when there is a sum.
-  const totalTokens = rows.reduce((sum, row) => {
-    const usage = usageOf(row);
-    return usage ? sum + rowTokens(usage) : sum;
-  }, 0);
-  const meta = [
-    `- Chat ID: \`${chatId}\``,
-    `- Exported: ${new Date().toISOString()}`,
-    `- Messages: ${rows.length}`,
-  ];
-  if (totalTokens > 0) meta.push(`- Total tokens: ${totalTokens}`);
-  blocks.push(meta.join('\n'));
-
-  rows.forEach((row, index) => {
-    blocks.push('---');
-
-    const roleLabel = row.role === 'assistant' ? L.aiAgent : L.you;
-    blocks.push(`## ${index + 1}. ${roleLabel}`);
-
-    // Created-at kept in source as an HTML comment (out of the rendered prose).
-    if (row.createdAt) {
-      const iso =
-        row.createdAt instanceof Date
-          ? row.createdAt.toISOString()
-          : String(row.createdAt);
-      blocks.push(`<!-- ${iso} -->`);
-    }
-
-    blocks.push(...renderMessageParts(rowParts(row), lang));
-
-    // A still-'streaming' row is an interrupted/in-progress turn captured by the
-    // export; record that so the partial answer is not mistaken for complete.
-    if (row.status === 'streaming') {
-      blocks.push(`_⏳ ${L.stillGenerating}_`);
-    }
-
-    const error = errorOf(row);
-    if (error) {
-      blocks.push(`**⚠️ Error:** ${error}`);
-    }
-
-    const usage = usageOf(row);
-    if (usage) {
-      const total = usage.totalTokens ?? rowTokens(usage);
-      const reasoning =
-        usage.reasoningTokens && usage.reasoningTokens > 0
-          ? `, reasoning: ${usage.reasoningTokens}`
-          : '';
-      blocks.push(
-        `_Tokens — in: ${usage.inputTokens ?? '?'}, out: ${
-          usage.outputTokens ?? '?'
-        }${reasoning}, total: ${total}_`,
-      );
-    }
-  });
-
-  // Blank line between blocks so the Markdown renders cleanly.
-  return blocks.join('\n\n');
-}

apps/server/src/core/ai-chat/dto/ai-chat.dto.ts

@@ -26,17 +26,3 @@ export class GetChatMessagesDto {
   @IsString()
   cursor?: string;
 }
-
-/** Export a chat to Markdown (#183). `lang` localizes the few fixed
- *  role/tool-action labels; defaults to English server-side. */
-export class ExportChatDto {
-  @IsString()
-  chatId: string;
-
-  // A full client locale tag (e.g. 'en-US', 'ru-RU') — normalized server-side to
-  // a supported export language (see normalizeLang). Accept any string so a
-  // region-qualified locale is not rejected (the 400 that broke the real client).
-  @IsOptional()
-  @IsString()
-  lang?: string;
-}

apps/server/src/core/ai-chat/external-mcp/dto/create-mcp-server.dto.ts

@@ -42,6 +42,15 @@ export class CreateMcpServerDto {
   @IsString({ each: true })
   toolAllowlist?: string[];
 
+  // Admin-authored guidance ("how/when to use this server's tools") injected
+  // into the agent system prompt next to the tool descriptions (#180). Trusted,
+  // NON-secret (so it IS returned). Capped to bound prompt/token size (the
+  // built-in guide is ~1.5KB). Blank => stored as null.
+  @IsOptional()
+  @IsString()
+  @MaxLength(4000)
+  instructions?: string;
+
   @IsOptional()
   @IsBoolean()
   enabled?: boolean;

apps/server/src/core/ai-chat/external-mcp/dto/mcp-server-instructions.dto.spec.ts

@@ -0,0 +1,75 @@
+import 'reflect-metadata';
+import { plainToInstance } from 'class-transformer';
+import { validateSync } from 'class-validator';
+import { CreateMcpServerDto } from './create-mcp-server.dto';
+import { UpdateMcpServerDto } from './update-mcp-server.dto';
+
+/**
+ * API-boundary validation for the per-server `instructions` field (#180): a free
+ * text guide injected into the agent system prompt. It is optional, must be a
+ * string, and is bounded by @MaxLength(4000) to cap prompt/token size.
+ */
+describe('MCP server DTO instructions validation', () => {
+  function validateCreate(payload: unknown) {
+    const dto = plainToInstance(CreateMcpServerDto, payload);
+    return validateSync(dto as object);
+  }
+  function validateUpdate(payload: unknown) {
+    const dto = plainToInstance(UpdateMcpServerDto, payload);
+    return validateSync(dto as object);
+  }
+
+  const base = {
+    name: 'Tavily',
+    transport: 'http',
+    url: 'https://example.com/mcp',
+  };
+
+  it('accepts an omitted instructions field on create', () => {
+    expect(validateCreate({ ...base })).toHaveLength(0);
+  });
+
+  it('accepts a reasonable instructions string on create', () => {
+    expect(
+      validateCreate({ ...base, instructions: 'Use search for fresh facts.' }),
+    ).toHaveLength(0);
+  });
+
+  it('rejects instructions over MaxLength(4000) on create', () => {
+    const errors = validateCreate({
+      ...base,
+      instructions: 'a'.repeat(4001),
+    });
+    expect(
+      errors.some(
+        (e) =>
+          e.property === 'instructions' &&
+          e.constraints !== undefined &&
+          'maxLength' in e.constraints,
+      ),
+    ).toBe(true);
+  });
+
+  it('accepts instructions of exactly 4000 chars on create', () => {
+    expect(
+      validateCreate({ ...base, instructions: 'a'.repeat(4000) }),
+    ).toHaveLength(0);
+  });
+
+  it('rejects a non-string instructions value', () => {
+    const errors = validateCreate({ ...base, instructions: 123 });
+    expect(errors.some((e) => e.property === 'instructions')).toBe(true);
+  });
+
+  it('rejects instructions over MaxLength(4000) on update', () => {
+    const errors = validateUpdate({ instructions: 'a'.repeat(4001) });
+    expect(
+      errors.some(
+        (e) =>
+          e.property === 'instructions' &&
+          e.constraints !== undefined &&
+          'maxLength' in e.constraints,
+      ),
+    ).toBe(true);
+  });
+});

apps/server/src/core/ai-chat/external-mcp/dto/update-mcp-server.dto.ts

@@ -43,6 +43,13 @@ export class UpdateMcpServerDto {
   @IsString({ each: true })
   toolAllowlist?: string[];
 
+  // Admin-authored prompt guidance (#180). Absent => unchanged; blank => cleared
+  // (stored as null by the repo). Capped to bound prompt/token size.
+  @IsOptional()
+  @IsString()
+  @MaxLength(4000)
+  instructions?: string;
+
   @IsOptional()
   @IsBoolean()
   enabled?: boolean;

apps/server/src/core/ai-chat/external-mcp/mcp-clients.service.ts

@@ -33,6 +33,26 @@ interface ServerOutcome {
   reason?: string;
 }
 
+/**
+ * One server's admin-authored guidance for the agent system prompt (#180).
+ * Built ONLY for a server that actually connected AND contributed ≥1 tool
+ * (after the allowlist filter) AND has non-blank guidance — so a guide never
+ * appears for a server whose tools the agent cannot actually call.
+ */
+export interface McpServerInstruction {
+  /** Display name of the server (for the prompt section header). */
+  serverName: string;
+  /**
+   * The tool-name namespace prefix the server's tools were merged under
+   * (sanitized name, e.g. `tavily`). The prompt renders this as `tavily_*` so
+   * the model can connect the guidance to the actual tool names. Advisory:
+   * individual tools may carry a disambiguating suffix on rare collisions.
+   */
+  toolPrefix: string;
+  /** The trusted, non-blank guidance text. */
+  instructions: string;
+}
+
 export interface ExternalToolset {
   /** Namespaced external tools, merge-ready into the agent toolset. */
   tools: Record<string, Tool>;
@@ -40,6 +60,11 @@ export interface ExternalToolset {
   clients: Closable[];
   /** Per-server connect outcomes so the UI can show unavailable servers. */
   outcomes: ServerOutcome[];
+  /**
+   * Per-server prompt guidance for connected servers that contributed ≥1 tool
+   * and have non-blank instructions. Empty when no server qualifies.
+   */
+  instructions: McpServerInstruction[];
 }
 
 /** Connect+tools() timeout per server — a slow server must not stall the turn. */
@@ -60,6 +85,8 @@ interface CacheEntry {
   tools: Record<string, Tool>;
   clients: McpClient[];
   outcomes: ServerOutcome[];
+  /** Prompt guidance for qualifying servers (see McpServerInstruction). */
+  instructions: McpServerInstruction[];
   expiresAt: number;
   /** Active leases (turns currently using these clients). */
   refCount: number;
@@ -141,6 +168,7 @@ export class McpClientsService {
       tools: entry.tools,
       clients: [release],
       outcomes: entry.outcomes,
+      instructions: entry.instructions,
     };
   }
 
@@ -225,6 +253,7 @@ export class McpClientsService {
     const outcomes: ServerOutcome[] = [];
     // Per-call total wall-clock cap, read once for this build (env-overridable).
     const callTimeoutMs = mcpCallTimeoutMs();
+    const instructions: McpServerInstruction[] = [];
 
     for (const server of servers) {
       try {
@@ -233,17 +262,33 @@ export class McpClientsService {
         clients.push(client);
         const allow = server.toolAllowlist;
         const picked =
-          Array.isArray(allow) && allow.length > 0
-            ? pick(raw, allow)
-            : raw;
+          Array.isArray(allow) && allow.length > 0 ? pick(raw, allow) : raw;
         // Bound each tool's execute with a per-call total-timeout guard before
         // merging, so a single chatty-but-stuck call is aborted after the cap.
         const guarded = wrapToolsWithCallTimeout(picked, callTimeoutMs);
         // Namespace each tool with the sanitized server name AND disambiguate
         // against names already merged from earlier servers, so no external
-        // tool is silently overwritten on collision.
-        this.mergeNamespaced(tools, guarded, server.name, server.id);
+        // tool is silently overwritten on collision. The returned count drives
+        // whether this server's prompt guidance is included (≥1 tool merged).
+        const merged = this.mergeNamespaced(
+          tools,
+          guarded,
+          server.name,
+          server.id,
+        );
         outcomes.push({ name: server.name, ok: true });
+        // Include this server's guidance ONLY when it actually contributed at
+        // least one tool the agent can call (allowlist may have filtered all of
+        // them out) AND the admin authored non-blank instructions. The header
+        // prefix is the sanitized server name (= the tool namespace prefix).
+        const guide = server.instructions?.trim();
+        if (merged.count > 0 && guide) {
+          instructions.push({
+            serverName: server.name,
+            toolPrefix: merged.prefix,
+            instructions: guide,
+          });
+        }
       } catch (err) {
         // A failed server is skipped — the turn proceeds with the rest. Log a
         // short warning (never the URL/headers) so ops can see degradation, and
@@ -260,6 +305,7 @@ export class McpClientsService {
       tools,
       clients,
       outcomes,
+      instructions,
       expiresAt: Date.now() + CACHE_TTL_MS,
       refCount: 0,
       evicted: false,
@@ -276,16 +322,19 @@ export class McpClientsService {
    * renaming any key that would collide with an already-merged tool (different
    * servers with the same sanitized name, or duplicates after truncation), so
    * no external tool is silently dropped via overwrite.
+   *
+   * Returns how many tools this server actually contributed and the namespace
+   * prefix used (the sanitized server name) so the caller can attach the
+   * server's prompt guidance only when ≥1 tool was merged.
    */
   private mergeNamespaced(
     target: Record<string, Tool>,
     picked: Record<string, Tool>,
     serverName: string,
     serverId: string,
-  ): void {
-    for (const [name, tool] of Object.entries(
-      namespace(picked, serverName),
-    )) {
+  ): { count: number; prefix: string } {
+    let count = 0;
+    for (const [name, tool] of Object.entries(namespace(picked, serverName))) {
       let key = name;
       if (key in target) {
         const original = key;
@@ -295,7 +344,9 @@ export class McpClientsService {
         );
       }
       target[key] = tool;
+      count += 1;
     }
+    return { count, prefix: namespacePrefix(serverName) };
   }
 
   /**
@@ -371,9 +422,7 @@ export class McpClientsService {
 
   /** Close clients, swallowing close errors so they never break a response. */
   private async closeClients(clients: McpClient[]): Promise<void> {
-    await Promise.all(
-      clients.map((c) => c.close().catch(() => undefined)),
-    );
+    await Promise.all(clients.map((c) => c.close().catch(() => undefined)));
   }
 }
 
@@ -386,9 +435,10 @@ export class McpClientsService {
  * lookup hands net/tls.connect ONLY a set that passed this check, so the kernel
  * can never connect to an address that did not pass the guard. Pure — no I/O.
  */
-export function validateResolvedAddresses(
-  addrs: readonly LookupAddress[],
-): { ok: boolean; blockedHost?: string } {
+export function validateResolvedAddresses(addrs: readonly LookupAddress[]): {
+  ok: boolean;
+  blockedHost?: string;
+} {
   if (addrs.length === 0) {
     return { ok: false };
   }
@@ -524,7 +574,7 @@ function namespace(
   tools: Record<string, Tool>,
   serverName: string,
 ): Record<string, Tool> {
-  const prefix = sanitizeName(serverName) || 'mcp';
+  const prefix = namespacePrefix(serverName);
   const out: Record<string, Tool> = {};
   for (const [name, t] of Object.entries(tools)) {
     const safe = sanitizeName(name);
@@ -539,6 +589,15 @@ function namespace(
   return out;
 }
 
+/**
+ * The tool-name namespace prefix for a server: its sanitized name, or `mcp`
+ * when the name sanitizes to empty. Tools are merged as `${prefix}_${tool}`, so
+ * the prompt guidance refers to the server's tools as `${prefix}_*`.
+ */
+function namespacePrefix(serverName: string): string {
+  return sanitizeName(serverName) || 'mcp';
+}
+
 /** Reduce an arbitrary string to ^[a-zA-Z0-9_-]+, collapsing runs to '_'. */
 function sanitizeName(value: string): string {
   return value

apps/server/src/core/ai-chat/external-mcp/mcp-instructions.spec.ts

@@ -0,0 +1,168 @@
+import { type Tool } from 'ai';
+import { McpClientsService } from './mcp-clients.service';
+
+/**
+ * Tests for the per-server prompt guidance (#180) assembled by buildEntry and
+ * surfaced via toolsFor().instructions.
+ *
+ * REACHABILITY NOTE: buildEntry is a PRIVATE method; the smallest reachable
+ * public path is toolsFor() -> getOrBuildEntry -> buildEntry -> connect/tools()
+ * -> mergeNamespaced. We drive that path: stub the repo's `listEnabled` and spy
+ * on the private `connect` to return fake MCP clients whose `tools()` we control.
+ *
+ * Contract (all checked here): a server's guidance is included ONLY when the
+ * server actually connected AND contributed ≥1 callable tool (after the
+ * allowlist filter) AND its instructions are non-blank. The header carries the
+ * tool namespace prefix (the sanitized server name).
+ */
+function fakeTool(): Tool {
+  return { description: 'x', inputSchema: undefined } as unknown as Tool;
+}
+
+interface FakeServer {
+  id: string;
+  name: string;
+  transport: string;
+  url: string;
+  headersEnc: string | null;
+  toolAllowlist: string[] | null;
+  instructions: string | null;
+}
+
+function server(
+  over: Partial<FakeServer> & { id: string; name: string },
+): FakeServer {
+  return {
+    transport: 'http',
+    url: 'https://example.com/mcp',
+    headersEnc: null,
+    toolAllowlist: null,
+    instructions: null,
+    ...over,
+  };
+}
+
+async function instructionsFor(
+  servers: FakeServer[],
+  toolsByServerId: Record<string, Record<string, Tool>>,
+  // Server ids whose connect should THROW (simulating an unavailable server).
+  failingIds: Set<string> = new Set(),
+): Promise<
+  {
+    serverName: string;
+    toolPrefix: string;
+    instructions: string;
+  }[]
+> {
+  const repoStub = {
+    listEnabled: jest.fn().mockResolvedValue(servers),
+  };
+  const service = new McpClientsService(repoStub as never, {} as never);
+
+  jest
+    .spyOn(
+      service as unknown as { connect: (s: FakeServer) => unknown },
+      'connect',
+    )
+    .mockImplementation((s: FakeServer) => {
+      if (failingIds.has(s.id)) {
+        return Promise.reject(new Error('connection failed'));
+      }
+      return Promise.resolve({
+        tools: () => Promise.resolve(toolsByServerId[s.id] ?? {}),
+        close: () => Promise.resolve(),
+      });
+    });
+
+  const toolset = await service.toolsFor('ws-1');
+  await Promise.all(toolset.clients.map((c) => c.close()));
+  return toolset.instructions;
+}
+
+describe('external MCP per-server prompt guidance (via toolsFor)', () => {
+  afterEach(() => jest.restoreAllMocks());
+
+  it('includes guidance for a connected server with non-empty text and ≥1 tool', async () => {
+    const instructions = await instructionsFor(
+      [
+        server({
+          id: 'id-tavily',
+          name: 'Tavily',
+          instructions: 'Use tavily_search for fresh facts.',
+        }),
+      ],
+      { 'id-tavily': { search: fakeTool() } },
+    );
+
+    // sanitizeName preserves case (charset [a-zA-Z0-9_-]), so the prefix is the
+    // server name as-is for an already-clean name.
+    expect(instructions).toEqual([
+      {
+        serverName: 'Tavily',
+        toolPrefix: 'Tavily',
+        instructions: 'Use tavily_search for fresh facts.',
+      },
+    ]);
+  });
+
+  it('omits guidance when the server has no instructions', async () => {
+    const instructions = await instructionsFor(
+      [server({ id: 'id-1', name: 'Tavily', instructions: null })],
+      { 'id-1': { search: fakeTool() } },
+    );
+    expect(instructions).toEqual([]);
+  });
+
+  it('omits guidance when the instructions are only whitespace', async () => {
+    const instructions = await instructionsFor(
+      [server({ id: 'id-1', name: 'Tavily', instructions: '   ' })],
+      { 'id-1': { search: fakeTool() } },
+    );
+    expect(instructions).toEqual([]);
+  });
+
+  it('omits guidance for a server that contributed ZERO tools (allowlist filtered all out)', async () => {
+    const instructions = await instructionsFor(
+      [
+        server({
+          id: 'id-1',
+          name: 'Tavily',
+          instructions: 'guide',
+          // Allowlist names a tool the server does not expose -> 0 picked.
+          toolAllowlist: ['nonexistent'],
+        }),
+      ],
+      { 'id-1': { search: fakeTool() } },
+    );
+    expect(instructions).toEqual([]);
+  });
+
+  it('omits guidance for an unavailable (failed-connect) server', async () => {
+    const instructions = await instructionsFor(
+      [server({ id: 'id-1', name: 'Tavily', instructions: 'guide' })],
+      { 'id-1': { search: fakeTool() } },
+      new Set(['id-1']),
+    );
+    expect(instructions).toEqual([]);
+  });
+
+  it('includes only the qualifying servers among several', async () => {
+    const instructions = await instructionsFor(
+      [
+        server({ id: 'ok', name: 'Tavily', instructions: 'web guide' }),
+        server({ id: 'blank', name: 'Crawl', instructions: '' }),
+        server({ id: 'down', name: 'Down', instructions: 'never shown' }),
+      ],
+      {
+        ok: { search: fakeTool() },
+        blank: { crawl: fakeTool() },
+        down: { x: fakeTool() },
+      },
+      new Set(['down']),
+    );
+
+    expect(instructions).toEqual([
+      { serverName: 'Tavily', toolPrefix: 'Tavily', instructions: 'web guide' },
+    ]);
+  });
+});

apps/server/src/core/ai-chat/external-mcp/mcp-servers-to-view.spec.ts

@@ -17,6 +17,7 @@ function row(overrides: Partial<AiMcpServer>): AiMcpServer {
     enabled: true,
     toolAllowlist: null,
     headersEnc: null,
+    instructions: null,
     ...overrides,
   } as unknown as AiMcpServer;
 }
@@ -28,11 +29,7 @@ describe('McpServersService.toView (via list) — encrypted-header leak guard',
     };
     // secretBox + clients are unused by the list/toView path; pass stubs to
     // satisfy the constructor.
-    return new McpServersService(
-      repoStub as never,
-      {} as never,
-      {} as never,
-    );
+    return new McpServersService(repoStub as never, {} as never, {} as never);
   }
 
   it('exposes hasHeaders:true and NO headersEnc when auth headers are set', async () => {
@@ -67,6 +64,7 @@ describe('McpServersService.toView (via list) — encrypted-header leak guard',
         enabled: false,
         toolAllowlist: ['search'],
         headersEnc: 'BLOB',
+        instructions: 'Use search for fresh web facts.',
       }),
     ]);
 
@@ -80,6 +78,19 @@ describe('McpServersService.toView (via list) — encrypted-header leak guard',
       enabled: false,
       toolAllowlist: ['search'],
       hasHeaders: true,
+      instructions: 'Use search for fresh web facts.',
     });
   });
+
+  it('returns instructions (NON-secret) in the view, null when unset', async () => {
+    const service = buildService([
+      row({ id: 'a', instructions: 'How to use these tools.' }),
+      row({ id: 'b', instructions: null }),
+    ]);
+
+    const [withText, withoutText] = await service.list('ws-1');
+
+    expect(withText.instructions).toBe('How to use these tools.');
+    expect(withoutText.instructions).toBeNull();
+  });
 });

apps/server/src/core/ai-chat/external-mcp/mcp-servers.service.ts

@@ -20,6 +20,9 @@ export interface McpServerView {
   enabled: boolean;
   toolAllowlist: string[] | null;
   hasHeaders: boolean;
+  // Admin-authored prompt guidance (#180). NON-secret, so returned in the view.
+  // Null when no guidance is configured.
+  instructions: string | null;
 }
 
 /**
@@ -56,6 +59,8 @@ export class McpServersService {
       url: dto.url,
       headersEnc,
       toolAllowlist: dto.toolAllowlist ?? null,
+      // Blank/whitespace guidance is normalized to null by the repo.
+      instructions: dto.instructions ?? null,
       enabled: dto.enabled ?? true,
     });
     this.clients.invalidate(workspaceId);
@@ -97,6 +102,8 @@ export class McpServersService {
       headersEnc,
       // undefined => unchanged; [] / value handled by repo (empty => null).
       toolAllowlist: dto.toolAllowlist,
+      // undefined => unchanged; blank => cleared (null) by the repo.
+      instructions: dto.instructions,
       enabled: dto.enabled,
     });
     this.clients.invalidate(workspaceId);
@@ -167,6 +174,7 @@ export class McpServersService {
       enabled: row.enabled,
       toolAllowlist: row.toolAllowlist ?? null,
       hasHeaders: Boolean(row.headersEnc),
+      instructions: row.instructions ?? null,
     };
   }
 }

apps/server/src/core/ai-chat/roles/jsonb-object.spec.ts

@@ -1,30 +0,0 @@
-import { jsonbObject } from '@docmost/db/repos/ai-agent-roles/ai-agent-roles.repo';
-
-/**
- * Unit tests for jsonbObject: the repo helper that encodes a model_config object
- * as a jsonb bind (or null when there is nothing to persist). It is the last
- * line of defence before the column write, so the null-vs-bind decision is what
- * matters here. We assert only null vs non-null because the non-null value is a
- * kysely `sql` template fragment whose internal shape is an implementation
- * detail of the SQL tag.
- */
-describe('jsonbObject', () => {
-  it('returns null for null', () => {
-    expect(jsonbObject(null)).toBeNull();
-  });
-
-  it('returns null for undefined', () => {
-    expect(jsonbObject(undefined)).toBeNull();
-  });
-
-  it('returns null for an empty object (nothing to persist)', () => {
-    expect(jsonbObject({})).toBeNull();
-  });
-
-  it('returns a (non-null) jsonb bind for a non-empty object', () => {
-    const out = jsonbObject({ driver: 'gemini', chatModel: 'gemini-2.0-flash' });
-    // A real sql fragment is produced, never null/undefined.
-    expect(out).not.toBeNull();
-    expect(out).toBeDefined();
-  });
-});

apps/server/src/core/share/share-seo.controller.routing.spec.ts

@@ -0,0 +1,133 @@
+import * as fs from 'node:fs';
+import { ShareSeoController } from './share-seo.controller';
+
+/**
+ * Routing guard for ShareSeoController.getShare (red-team finding #3).
+ *
+ * The SEO route must NOT leak a shared page's <title>/og:title to anonymous
+ * visitors / crawlers when the page is not publicly readable. It previously
+ * called the raw `getShareForPage`, which skips the restricted-ancestor gate, so
+ * a permission-restricted descendant of an includeSubPages share leaked its
+ * title. The fix funnels through `resolveReadableSharePage` (the canonical gate)
+ * AND honours `isSharingAllowed`. These tests pin that routing: a non-readable
+ * page or sharing-disabled space serves the plain SPA index (no title); only a
+ * readable, still-shared page gets meta tags.
+ */
+
+const SECRET_TITLE = 'Restricted Quarterly Numbers';
+const INDEX_HTML = `<!doctype html><html><head><title>App</title><!--meta-tags--></head><body></body></html>`;
+const STREAM_SENTINEL = { __isStream: true } as unknown as fs.ReadStream;
+
+// Stub fs at CALL time (jest.spyOn), NOT module load (jest.mock): the controller
+// transitively pulls bcrypt, whose native module is located by node-gyp-build
+// reading the filesystem at import time — a module-level fs mock breaks that.
+beforeEach(() => {
+  jest.spyOn(fs, 'existsSync').mockReturnValue(true);
+  jest.spyOn(fs, 'readFileSync').mockReturnValue(INDEX_HTML);
+  jest.spyOn(fs, 'createReadStream').mockReturnValue(STREAM_SENTINEL);
+});
+afterEach(() => jest.restoreAllMocks());
+
+function makeRes() {
+  const res: any = {
+    sent: undefined as unknown,
+    type: jest.fn(() => res),
+    send: jest.fn((v: unknown) => {
+      res.sent = v;
+    }),
+  };
+  return res;
+}
+
+function makeController(opts: {
+  resolved: { share: any; page: any } | null;
+  sharingAllowed?: boolean;
+}) {
+  const shareService = {
+    resolveReadableSharePage: jest.fn(async () => opts.resolved),
+    isSharingAllowed: jest.fn(async () => opts.sharingAllowed ?? true),
+    // Must NEVER be used by the SEO path anymore (the bypass is the bug).
+    getShareForPage: jest.fn(async () => {
+      throw new Error('getShareForPage must not be called by the SEO path');
+    }),
+  };
+  const workspaceRepo = {
+    findFirst: async () => ({ id: 'ws-1', settings: {} }),
+  };
+  const environmentService = { isSelfHosted: () => true };
+  const controller = new ShareSeoController(
+    shareService as any,
+    workspaceRepo as any,
+    environmentService as any,
+  );
+  return { controller, shareService };
+}
+
+const req: any = { raw: { headers: { host: 'self' } } };
+
+describe('ShareSeoController.getShare routing (#3 title-leak gate)', () => {
+  it('serves the plain index (NO title) when the page is not publicly readable', async () => {
+    const { controller, shareService } = makeController({ resolved: null });
+    const res = makeRes();
+
+    await controller.getShare(res, req, 'share-key', `slug-pageB`);
+
+    // The restricted-ancestor gate ran; the raw bypass did not.
+    expect(shareService.resolveReadableSharePage).toHaveBeenCalled();
+    expect(shareService.getShareForPage).not.toHaveBeenCalled();
+    // The plain index stream was sent — NOT the title-bearing meta HTML.
+    expect(res.sent).toBe(STREAM_SENTINEL);
+  });
+
+  it('serves the plain index when sharing was disabled at the workspace/space level', async () => {
+    const { controller } = makeController({
+      resolved: {
+        share: { spaceId: 'sp-1', searchIndexing: true },
+        page: { title: SECRET_TITLE },
+      },
+      sharingAllowed: false,
+    });
+    const res = makeRes();
+
+    await controller.getShare(res, req, 'share-key', 'slug-pageB');
+
+    // The plain index stream was sent, so the restricted title never reached
+    // the response (it is only ever interpolated into the meta HTML string).
+    expect(res.sent).toBe(STREAM_SENTINEL);
+    expect(res.sent).not.toBe(SECRET_TITLE);
+  });
+
+  it('injects the title + meta for a readable, still-shared page', async () => {
+    const { controller } = makeController({
+      resolved: {
+        share: { spaceId: 'sp-1', searchIndexing: true },
+        page: { title: 'Public Handbook' },
+      },
+      sharingAllowed: true,
+    });
+    const res = makeRes();
+
+    await controller.getShare(res, req, 'share-key', 'slug-pageA');
+
+    expect(typeof res.sent).toBe('string');
+    expect(res.sent as string).toContain('<title>Public Handbook</title>');
+    expect(res.sent as string).toContain('og:title');
+    // searchIndexing on => crawlable (no noindex).
+    expect(res.sent as string).not.toContain('content="noindex"');
+  });
+
+  it('adds robots=noindex when the share opted out of search indexing', async () => {
+    const { controller } = makeController({
+      resolved: {
+        share: { spaceId: 'sp-1', searchIndexing: false },
+        page: { title: 'Internal Notes' },
+      },
+      sharingAllowed: true,
+    });
+    const res = makeRes();
+
+    await controller.getShare(res, req, 'share-key', 'slug-pageA');
+
+    expect(res.sent as string).toContain('content="noindex"');
+  });
+});

apps/server/src/core/share/share-seo.controller.ts

@@ -63,19 +63,38 @@ export class ShareSeoController {
 
       const pageId = this.extractPageSlugId(pageSlug);
 
-      const share = await this.shareService.getShareForPage(
+      // Funnel through the canonical readable-share boundary (NOT the raw
+      // getShareForPage) so the restricted-ancestor gate runs: a permission-
+      // restricted descendant of an includeSubPages share must NOT leak its
+      // title to anonymous visitors / crawlers (red-team finding #3). null =>
+      // not publicly readable => serve the plain SPA index with no meta.
+      const resolved = await this.shareService.resolveReadableSharePage(
+        undefined,
         pageId,
         workspace.id,
       );
 
-      if (!share) {
+      if (!resolved) {
+        return this.sendIndex(indexFilePath, res);
+      }
+
+      // Honour a workspace/space-level sharing toggle flipped off AFTER this
+      // share was created: the content API gates on isSharingAllowed, so the SEO
+      // path must too or it keeps serving the title for a no-longer-shared page.
+      const sharingAllowed = await this.shareService.isSharingAllowed(
+        workspace.id,
+        resolved.share.spaceId,
+      );
+      if (!sharingAllowed) {
         return this.sendIndex(indexFilePath, res);
       }
 
       const html = fs.readFileSync(indexFilePath, 'utf8');
+      // Title of the PAGE being viewed (server-resolved), and noindex unless the
+      // share opted into search indexing (buildShareMetaHtml injects it).
       let transformedHtml = buildShareMetaHtml(html, {
-        title: share?.sharedPage.title,
-        searchIndexing: share.searchIndexing,
+        title: resolved.page.title,
+        searchIndexing: resolved.share.searchIndexing,
       });
 
       // Deliberate same-origin tracker surface: this is the ONE place where an

apps/server/src/database/jsonb-bind.spec.ts

@@ -0,0 +1,38 @@
+import { jsonbBind } from './utils';
+
+/**
+ * Unit tests for jsonbBind: THE shared helper that encodes a JS array/object as
+ * a jsonb bind (or null when there is nothing to persist). It is the last line
+ * of defence before a jsonb column write, so the null-vs-bind decision is what
+ * matters here. We assert only null vs non-null because the non-null value is a
+ * kysely `sql` template fragment whose internal shape is an implementation
+ * detail of the SQL tag (the `::text::jsonb` double-encoding fix is verified
+ * end-to-end by the repo integration specs, where a real DB round-trip can
+ * actually observe `jsonb_typeof`).
+ */
+describe('jsonbBind', () => {
+  it('returns null for null / undefined', () => {
+    expect(jsonbBind(null)).toBeNull();
+    expect(jsonbBind(undefined)).toBeNull();
+  });
+
+  it('returns null for an empty array (nothing to persist)', () => {
+    expect(jsonbBind([])).toBeNull();
+  });
+
+  it('returns null for an empty object (nothing to persist)', () => {
+    expect(jsonbBind({})).toBeNull();
+  });
+
+  it('returns a (non-null) bind for a non-empty array', () => {
+    const out = jsonbBind(['search', 'crawl']);
+    expect(out).not.toBeNull();
+    expect(out).toBeDefined();
+  });
+
+  it('returns a (non-null) bind for a non-empty object', () => {
+    const out = jsonbBind({ driver: 'gemini', chatModel: 'gemini-2.0-flash' });
+    expect(out).not.toBeNull();
+    expect(out).toBeDefined();
+  });
+});

apps/server/src/database/migrations/20260625T120000-ai-mcp-servers-instructions.ts

@@ -0,0 +1,19 @@
+import { type Kysely } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  // Per-server, admin-authored instruction text injected into the agent system
+  // prompt next to the server's tool descriptions (#180). NON-secret (unlike
+  // headers_enc): it IS returned in admin views/forms. Nullable: a server may
+  // have no guidance. Trusted text — it goes inside the prompt safety sandwich.
+  await db.schema
+    .alterTable('ai_mcp_servers')
+    .addColumn('instructions', 'text', (col) => col)
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .alterTable('ai_mcp_servers')
+    .dropColumn('instructions')
+    .execute();
+}

apps/server/src/database/migrations/20260626T120000-ai-chat-message-status.ts

@@ -1,18 +0,0 @@
-import { type Kysely } from 'kysely';
-
-export async function up(db: Kysely<any>): Promise<void> {
-  // Step-granular durability for the assistant turn (#183). The assistant row is
-  // now created UPFRONT (status 'streaming') and UPDATEd as each step completes,
-  // so a process death mid-turn no longer loses the whole answer. The column is
-  // NULLABLE on purpose: rows written before this migration carry NULL, which the
-  // app treats as 'completed' (a settled, pre-status message). Values written by
-  // the app: 'streaming' | 'completed' | 'error' | 'aborted'.
-  await db.schema
-    .alterTable('ai_chat_messages')
-    .addColumn('status', 'text', (col) => col)
-    .execute();
-}
-
-export async function down(db: Kysely<any>): Promise<void> {
-  await db.schema.alterTable('ai_chat_messages').dropColumn('status').execute();
-}

apps/server/src/database/repos/ai-agent-roles/ai-agent-roles.repo.spec.ts

@@ -35,7 +35,13 @@ describe('AiAgentRoleRepo.findLiveEnabled', () => {
 
     const result = await repo.findLiveEnabled('r-1', 'ws-1');
 
-    expect(result).toBe(role);
+    // The repo normalizes the row (modelConfig parse), so it returns a COPY, not
+    // the same reference; assert the row's fields are carried through.
+    expect(result).toMatchObject({
+      id: 'r-1',
+      workspaceId: 'ws-1',
+      enabled: true,
+    });
     expect(db.selectFrom).toHaveBeenCalledWith('aiAgentRoles');
     // Every security filter must be present.
     expect(where).toHaveBeenCalledWith('id', '=', 'r-1');

apps/server/src/database/repos/ai-agent-roles/ai-agent-roles.repo.ts

@@ -1,8 +1,7 @@
 import { Injectable } from '@nestjs/common';
 import { InjectKysely } from 'nestjs-kysely';
-import { sql } from 'kysely';
 import { KyselyDB, KyselyTransaction } from '../../types/kysely.types';
-import { dbOrTx } from '../../utils';
+import { dbOrTx, jsonbBind } from '../../utils';
 import { AiAgentRole } from '@docmost/db/types/entity.types';
 
 /** The jsonb shape persisted in `model_config` (loosely typed for the column). */
@@ -23,13 +22,14 @@ export class AiAgentRoleRepo {
     id: string,
     workspaceId: string,
   ): Promise<AiAgentRole | undefined> {
-    return this.db
+    const row = await this.db
       .selectFrom('aiAgentRoles')
       .selectAll('aiAgentRoles')
       .where('id', '=', id)
       .where('workspaceId', '=', workspaceId)
       .where('deletedAt', 'is', null)
       .executeTakeFirst();
+    return row ? normalizeRow(row) : row;
   }
 
   /**
@@ -45,7 +45,7 @@ export class AiAgentRoleRepo {
     id: string,
     workspaceId: string,
   ): Promise<AiAgentRole | undefined> {
-    return this.db
+    const row = await this.db
       .selectFrom('aiAgentRoles')
       .selectAll('aiAgentRoles')
       .where('id', '=', id)
@@ -53,17 +53,19 @@ export class AiAgentRoleRepo {
       .where('deletedAt', 'is', null)
       .where('enabled', '=', true)
       .executeTakeFirst();
+    return row ? normalizeRow(row) : row;
   }
 
   /** All live roles for the workspace (management list + chat picker). */
   async listByWorkspace(workspaceId: string): Promise<AiAgentRole[]> {
-    return this.db
+    const rows = await this.db
       .selectFrom('aiAgentRoles')
       .selectAll('aiAgentRoles')
       .where('workspaceId', '=', workspaceId)
       .where('deletedAt', 'is', null)
       .orderBy('createdAt', 'asc')
       .execute();
+    return rows.map(normalizeRow);
   }
 
   async insert(
@@ -83,7 +85,7 @@ export class AiAgentRoleRepo {
     trx?: KyselyTransaction,
   ): Promise<AiAgentRole> {
     const db = dbOrTx(this.db, trx);
-    return db
+    const row = await db
       .insertInto('aiAgentRoles')
       .values({
         workspaceId: values.workspaceId,
@@ -92,7 +94,11 @@ export class AiAgentRoleRepo {
         emoji: values.emoji ?? null,
         description: values.description ?? null,
         instructions: values.instructions,
-        modelConfig: jsonbObject(values.modelConfig),
+        // Cast: the generated `model_config` column type is the broad JsonValue
+        // union, which the concrete RawBuilder<Record> is not structurally
+        // assignable to (same reason the old jsonbObject cast to any).
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        modelConfig: jsonbBind(values.modelConfig) as any,
         enabled: values.enabled ?? true,
         autoStart: values.autoStart ?? true,
         // Empty string is treated as "no custom text" => null.
@@ -100,6 +106,7 @@ export class AiAgentRoleRepo {
       })
       .returningAll()
       .executeTakeFirst();
+    return normalizeRow(row);
   }
 
   async update(
@@ -127,7 +134,7 @@ export class AiAgentRoleRepo {
     if (patch.description !== undefined) set.description = patch.description;
     if (patch.instructions !== undefined) set.instructions = patch.instructions;
     if (patch.modelConfig !== undefined) {
-      set.modelConfig = jsonbObject(patch.modelConfig);
+      set.modelConfig = jsonbBind(patch.modelConfig);
     }
     if (patch.enabled !== undefined) set.enabled = patch.enabled;
     if (patch.autoStart !== undefined) set.autoStart = patch.autoStart;
@@ -163,16 +170,40 @@ export class AiAgentRoleRepo {
 }
 
 /**
- * Encode an object as a jsonb bind for the `model_config` column. The postgres
- * driver would otherwise need an explicit cast; bind the JSON text and cast it.
- * Returns null for null/undefined/empty objects. Cast to `any` because the
- * generated column type is the broad `JsonValue` union, which a concrete object
- * type is not structurally assignable to.
+ * Parse the `model_config` value read from the DB into the object the entity
+ * type promises. Rows written by the old double-encoding bind (`::jsonb` instead
+ * of `::text::jsonb`) round-trip as a JSON STRING, so the driver hands back e.g.
+ * `'{"driver":"gemini"}'` rather than an object; the read-path check
+ * `typeof cfg === 'object'` then failed and the model override was SILENTLY
+ * dropped (the role fell back to the default model). Be tolerant: a JSON string
+ * is parsed; an already-parsed object passes through; null / a non-object (incl.
+ * an array) / unparseable value becomes null (= no override). This self-heals
+ * already-corrupted rows on read, no migration required.
  */
-export function jsonbObject(value: ModelConfigValue | undefined) {
-  if (value === null || value === undefined || Object.keys(value).length === 0) {
-    return null;
+export function parseModelConfig(
+  value: unknown,
+): Record<string, unknown> | null {
+  let v: unknown = value;
+  if (typeof v === 'string') {
+    try {
+      v = JSON.parse(v); // legacy double-encoded read
+    } catch {
+      return null;
+    }
   }
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  return sql`${JSON.stringify(value)}::jsonb` as any;
+  return v !== null && typeof v === 'object' && !Array.isArray(v)
+    ? (v as Record<string, unknown>)
+    : null;
+}
+
+/** Normalize a DB row so `modelConfig` is always an object or null. The cast
+ *  bridges parseModelConfig's concrete `Record | null` to the column's broad
+ *  generated `JsonValue` type (an object is a valid JsonValue at runtime). */
+function normalizeRow(row: AiAgentRole): AiAgentRole {
+  return {
+    ...row,
+    modelConfig: parseModelConfig(
+      row.modelConfig,
+    ) as AiAgentRole['modelConfig'],
+  };
 }

apps/server/src/database/repos/ai-agent-roles/parse-model-config.spec.ts

@@ -0,0 +1,46 @@
+import { parseModelConfig } from './ai-agent-roles.repo';
+
+/**
+ * Unit tests for parseModelConfig: the read-side normalizer that repairs the
+ * jsonb double-encoding regression on `model_config`. Rows written by the old
+ * `::jsonb` bind round-trip as a JSON STRING, which the read path's
+ * `typeof === 'object'` check rejected — silently dropping the model override.
+ * parseModelConfig accepts an already-parsed object, parses a legacy JSON
+ * string, and rejects everything that is not an object (null = no override).
+ */
+describe('parseModelConfig', () => {
+  it('passes an already-parsed object through', () => {
+    expect(parseModelConfig({ driver: 'gemini' })).toEqual({
+      driver: 'gemini',
+    });
+  });
+
+  it('parses a legacy double-encoded JSON string into an object', () => {
+    expect(parseModelConfig('{"driver":"gemini","chatModel":"x"}')).toEqual({
+      driver: 'gemini',
+      chatModel: 'x',
+    });
+  });
+
+  it('returns null for null / undefined', () => {
+    expect(parseModelConfig(null)).toBeNull();
+    expect(parseModelConfig(undefined)).toBeNull();
+  });
+
+  it('returns null for a non-object JSON value (string/number/array)', () => {
+    expect(parseModelConfig('"justastring"')).toBeNull();
+    expect(parseModelConfig('42')).toBeNull();
+    // An array is an object in JS but not a valid model_config shape.
+    expect(parseModelConfig('["a","b"]')).toBeNull();
+    expect(parseModelConfig(['a', 'b'])).toBeNull();
+  });
+
+  it('returns null for an unparseable string', () => {
+    expect(parseModelConfig('not json at all')).toBeNull();
+  });
+
+  it('returns null for a raw non-object primitive', () => {
+    expect(parseModelConfig(42 as unknown)).toBeNull();
+    expect(parseModelConfig(true as unknown)).toBeNull();
+  });
+});

apps/server/src/database/repos/ai-chat/ai-chat-message.repo.ts

@@ -1,4 +1,4 @@
-import { Injectable, Logger } from '@nestjs/common';
+import { Injectable } from '@nestjs/common';
 import { InjectKysely } from 'nestjs-kysely';
 import { KyselyDB, KyselyTransaction } from '../../types/kysely.types';
 import { dbOrTx } from '../../utils';
@@ -9,24 +9,8 @@ import {
 import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
 import { executeWithCursorPagination } from '@docmost/db/pagination/cursor-pagination';
 
-// Crash-recovery sweep recency threshold (#183 review): a 'streaming' row is
-// only swept to 'aborted' once it has been UNTOUCHED for this long. A live turn
-// bumps `updatedAt` on every step (well under this window), so its row never
-// matches; only a turn whose process truly died (no step update for >threshold)
-// is swept. Chosen safely ABOVE the longest realistic turn so a fresh replica's
-// boot-sweep can never abort a turn another replica is actively streaming
-// (multi-instance deploy).
-const SWEEP_STREAMING_STALE_MS = 10 * 60 * 1000; // 10 minutes
-
-// Hard upper bound on the rows materialized by `findAllByChat` (export path).
-// A generous cap so a pathologically huge chat cannot load an unbounded result
-// into memory; far above any realistic transcript length.
-const FIND_ALL_BY_CHAT_LIMIT = 5000;
-
 @Injectable()
 export class AiChatMessageRepo {
-  private readonly logger = new Logger(AiChatMessageRepo.name);
-
   constructor(@InjectKysely() private readonly db: KyselyDB) {}
 
   // The `tsv` column is a trigger-maintained tsvector used only for
@@ -41,7 +25,6 @@ export class AiChatMessageRepo {
     'content',
     'toolCalls',
     'metadata',
-    'status',
     'createdAt',
     'updatedAt',
     'deletedAt',
@@ -77,46 +60,6 @@ export class AiChatMessageRepo {
     });
   }
 
-  // Load ALL (non-deleted) messages of a chat in ascending chronological order
-  // (oldest -> newest), unpaginated. Used by the server-side Markdown export
-  // (#183), where the DB is the single source of truth and the whole transcript
-  // must be rendered in one pass (findByChat is cursor-paginated and would only
-  // return the first page).
-  //
-  // Hard-capped at FIND_ALL_BY_CHAT_LIMIT rows (a generous bound, far above any
-  // realistic transcript) so exporting a pathologically huge chat cannot
-  // materialize an unbounded result set in memory.
-  async findAllByChat(
-    chatId: string,
-    workspaceId: string,
-    // Injectable for tests so truncation can be exercised on a modest volume.
-    limit: number = FIND_ALL_BY_CHAT_LIMIT,
-  ): Promise<AiChatMessage[]> {
-    // Fetch newest-first (+1 to DETECT truncation), so on overflow we keep the
-    // NEWEST `limit` messages — the recent conversation matters most for an
-    // export — rather than silently dropping the tail (#183 review). Reverse back
-    // to chronological for rendering, like findRecent.
-    const rows = await this.db
-      .selectFrom('aiChatMessages')
-      .select(this.baseFields)
-      .where('chatId', '=', chatId)
-      .where('workspaceId', '=', workspaceId)
-      .where('deletedAt', 'is', null)
-      .orderBy('createdAt', 'desc')
-      .orderBy('id', 'desc')
-      .limit(limit + 1)
-      .execute();
-
-    if (rows.length > limit) {
-      rows.length = limit; // keep the newest `limit` (rows are newest-first here)
-      this.logger.warn(
-        `Chat ${chatId} export truncated to the newest ${limit} messages ` +
-          `(older messages omitted).`,
-      );
-    }
-    return rows.reverse();
-  }
-
   // Load the most RECENT `limit` messages for a chat and return them in
   // ascending chronological order (oldest -> newest), as the model expects.
   // `findByChat` returns the FIRST page ASC (the OLDEST messages), which loses
@@ -153,68 +96,4 @@ export class AiChatMessageRepo {
       .returning(this.baseFields)
       .executeTakeFirst();
   }
-
-  /**
-   * Update a single message in place by id + workspace (#183 step-granular
-   * durability). The assistant row is created UPFRONT (status 'streaming') and
-   * patched as each step completes, then finalized once on the terminal status.
-   * `updatedAt` is always bumped. Returns the updated row (baseFields) or
-   * undefined when no row matched (e.g. a foreign workspace / deleted row).
-   */
-  async update(
-    id: string,
-    workspaceId: string,
-    patch: Partial<{
-      content: string | null;
-      toolCalls: unknown;
-      metadata: unknown;
-      status: string | null;
-    }>,
-    opts?: { onlyIfStreaming?: boolean; trx?: KyselyTransaction },
-  ): Promise<AiChatMessage | undefined> {
-    const db = dbOrTx(this.db, opts?.trx);
-    let query = db
-      .updateTable('aiChatMessages')
-      .set({ ...(patch as Record<string, unknown>), updatedAt: new Date() })
-      .where('id', '=', id)
-      .where('workspaceId', '=', workspaceId);
-    // Concurrency guard (#183 review): a per-step 'streaming' update must NEVER
-    // overwrite a row the terminal callback already finalized. onStepFinish
-    // fires the streaming update fire-and-forget, so its UPDATE can land AFTER
-    // finalize on a DIFFERENT pool connection (commit order is not guaranteed).
-    // Scoping the streaming update to rows STILL in 'streaming' makes a late
-    // update a no-op once the row is completed/error/aborted — regardless of
-    // commit order. The terminal finalize runs WITHOUT this guard so it always
-    // wins.
-    if (opts?.onlyIfStreaming) {
-      query = query.where('status', '=', 'streaming');
-    }
-    return query.returning(this.baseFields).executeTakeFirst();
-  }
-
-  /**
-   * Crash-recovery sweep (#183): flip every assistant row still left in the
-   * 'streaming' state (a turn that died mid-write before reaching a terminal
-   * status) to 'aborted'. Run once on server start. Returns the number of rows
-   * swept so the caller can log it. Workspace-wide on purpose — a crash can have
-   * dangling streaming rows across any workspace.
-   *
-   * Bounded by recency (#183 review): only rows UNTOUCHED for
-   * SWEEP_STREAMING_STALE_MS are swept. A live turn bumps `updatedAt` on every
-   * step, so an actively-streaming row never matches; this prevents a fresh
-   * replica's boot-sweep from aborting a turn another replica is still streaming
-   * in a multi-instance deploy.
-   */
-  async sweepStreaming(trx?: KyselyTransaction): Promise<number> {
-    const db = dbOrTx(this.db, trx);
-    const staleBefore = new Date(Date.now() - SWEEP_STREAMING_STALE_MS);
-    const rows = await db
-      .updateTable('aiChatMessages')
-      .set({ status: 'aborted', updatedAt: new Date() })
-      .where('status', '=', 'streaming')
-      .where('updatedAt', '<', staleBefore)
-      .returning('id')
-      .execute();
-    return rows.length;
-  }
 }

apps/server/src/database/repos/ai-chat/ai-mcp-server.repo.spec.ts

@@ -1,4 +1,4 @@
-import { parseToolAllowlist } from './ai-mcp-server.repo';
+import { parseToolAllowlist, blankToNull } from './ai-mcp-server.repo';
 
 /**
  * The `tool_allowlist` jsonb column historically round-trips as a JSON STRING
@@ -10,7 +10,10 @@ import { parseToolAllowlist } from './ai-mcp-server.repo';
  */
 describe('parseToolAllowlist', () => {
   it('passes a real string array through unchanged', () => {
-    expect(parseToolAllowlist(['search', 'crawl'])).toEqual(['search', 'crawl']);
+    expect(parseToolAllowlist(['search', 'crawl'])).toEqual([
+      'search',
+      'crawl',
+    ]);
   });
 
   it('parses a JSON-string array (the double-encoded read) into an array', () => {
@@ -46,3 +49,26 @@ describe('parseToolAllowlist', () => {
     expect(parseToolAllowlist(true as unknown)).toBeNull();
   });
 });
+
+/**
+ * `blankToNull` normalizes the per-server `instructions` free text before it is
+ * stored (#180): a missing/blank/whitespace-only value becomes null (so an empty
+ * guide is never persisted), any other value is trimmed.
+ */
+describe('blankToNull', () => {
+  it('returns null for null / undefined', () => {
+    expect(blankToNull(null)).toBeNull();
+    expect(blankToNull(undefined)).toBeNull();
+  });
+
+  it('returns null for an empty / whitespace-only string', () => {
+    expect(blankToNull('')).toBeNull();
+    expect(blankToNull('   ')).toBeNull();
+    expect(blankToNull('\n\t ')).toBeNull();
+  });
+
+  it('trims and returns a non-blank string', () => {
+    expect(blankToNull('  use the search tool  ')).toBe('use the search tool');
+    expect(blankToNull('guide')).toBe('guide');
+  });
+});

apps/server/src/database/repos/ai-chat/ai-mcp-server.repo.ts

@@ -1,10 +1,11 @@
-import { Injectable } from '@nestjs/common';
+import { Injectable, Logger } from '@nestjs/common';
 import { InjectKysely } from 'nestjs-kysely';
-import { sql } from 'kysely';
 import { KyselyDB, KyselyTransaction } from '../../types/kysely.types';
-import { dbOrTx } from '../../utils';
+import { dbOrTx, jsonbBind } from '../../utils';
 import { AiMcpServer } from '@docmost/db/types/entity.types';
 
+const logger = new Logger('AiMcpServerRepo');
+
 /**
  * Repository for per-workspace external MCP servers the agent may use (§5.4).
  *
@@ -60,6 +61,8 @@ export class AiMcpServerRepo {
       url: string;
       headersEnc?: string | null;
       toolAllowlist?: string[] | null;
+      // Admin-authored prompt guidance; blank/whitespace normalizes to null.
+      instructions?: string | null;
       enabled?: boolean;
     },
     trx?: KyselyTransaction,
@@ -75,7 +78,9 @@ export class AiMcpServerRepo {
         headersEnc: values.headersEnc ?? null,
         // jsonb column: the postgres driver would otherwise encode a JS array as
         // a Postgres array literal. Bind the JSON text and cast it to jsonb.
-        toolAllowlist: jsonbArray(values.toolAllowlist),
+        toolAllowlist: jsonbBind(values.toolAllowlist),
+        // Plain text column: blank/whitespace-only guidance is stored as null.
+        instructions: blankToNull(values.instructions),
         enabled: values.enabled ?? true,
       })
       .returningAll()
@@ -93,6 +98,8 @@ export class AiMcpServerRepo {
       headersEnc?: string | null;
       // undefined => leave unchanged; null => clear; string[] => set.
       toolAllowlist?: string[] | null;
+      // undefined => leave unchanged; null/blank => clear; string => set.
+      instructions?: string | null;
       enabled?: boolean;
     },
     trx?: KyselyTransaction,
@@ -104,7 +111,11 @@ export class AiMcpServerRepo {
     if (patch.url !== undefined) set.url = patch.url;
     if (patch.headersEnc !== undefined) set.headersEnc = patch.headersEnc;
     if (patch.toolAllowlist !== undefined) {
-      set.toolAllowlist = jsonbArray(patch.toolAllowlist);
+      set.toolAllowlist = jsonbBind(patch.toolAllowlist);
+    }
+    if (patch.instructions !== undefined) {
+      // Blank/whitespace-only guidance clears the column (stored as null).
+      set.instructions = blankToNull(patch.instructions);
     }
     if (patch.enabled !== undefined) set.enabled = patch.enabled;
     await db
@@ -130,57 +141,53 @@ export class AiMcpServerRepo {
 }
 
 /**
- * Encode a string[] as a jsonb bind for the `tool_allowlist` column. Passing a
- * plain JS array to the postgres driver would serialize it as a Postgres array
- * literal (incompatible with jsonb), so we bind the JSON text and cast it.
- *
- * The cast is `::text::jsonb`, NOT `::jsonb`: if the parameter is bound straight
- * to a jsonb cast, node-postgres infers its type as jsonb and JSON-stringifies
- * the (already-JSON) string a SECOND time, so the column ends up holding a jsonb
- * STRING SCALAR (`"[\"a\"]"`) instead of a jsonb ARRAY. Forcing the param through
- * `::text` first binds it as text (sent verbatim), and `::jsonb` then parses it
- * into a real array. (`normalizeRow` below repairs rows written the old way.)
- *
- * Returns null for null/empty arrays (an empty allowlist means "no restriction"
- * is not intended — callers pass null to clear; an empty array is normalized to
- * null here so it never round-trips as `[]`).
+ * Normalize an optional free-text field to a stored value: a missing/blank/
+ * whitespace-only string becomes null (so an "empty" guide is never persisted),
+ * any other string is trimmed. Returns null for null/undefined input.
  */
-function jsonbArray(value: string[] | null | undefined) {
-  if (value === null || value === undefined || value.length === 0) {
-    return null;
-  }
-  // Typed as string[] so it is assignable to the toolAllowlist column.
-  return sql<string[]>`${JSON.stringify(value)}::text::jsonb`;
+export function blankToNull(value: string | null | undefined): string | null {
+  if (value == null) return null;
+  const trimmed = value.trim();
+  return trimmed.length > 0 ? trimmed : null;
 }
 
 /**
  * Parse the `toolAllowlist` value read from the DB into the `string[] | null`
  * the entity type promises. The jsonb column historically round-trips as a JSON
- * STRING (rows written by the old double-encoding `jsonbArray`, see above), so
- * the driver hands back a string like `'["a","b"]'` rather than an array. Be
- * tolerant: an already-parsed array passes through; a JSON string is parsed; null
- * / a non-array / unparseable value becomes null (unrestricted).
+ * STRING (rows written by the old double-encoding bind before the `::text::jsonb`
+ * fix), so the driver hands back a string like `'["a","b"]'` rather than an
+ * array. Be tolerant: normalize a JSON string to its value, then accept it only
+ * if it is an array of strings; null / a non-array / unparseable value / an
+ * array with a non-string element all become null (unrestricted).
  */
 export function parseToolAllowlist(value: unknown): string[] | null {
-  if (value == null) return null;
-  if (Array.isArray(value)) {
-    return value.every((v) => typeof v === 'string') ? (value as string[]) : null;
-  }
-  if (typeof value === 'string') {
+  let v: unknown = value;
+  if (typeof v === 'string') {
     try {
-      const parsed = JSON.parse(value);
-      return Array.isArray(parsed) &&
-        parsed.every((v) => typeof v === 'string')
-        ? (parsed as string[])
-        : null;
+      v = JSON.parse(v); // legacy double-encoded read
     } catch {
       return null;
     }
   }
-  return null;
+  return Array.isArray(v) && v.every((x) => typeof x === 'string')
+    ? (v as string[])
+    : null;
 }
 
-/** Normalize a DB row so `toolAllowlist` is always `string[] | null`. */
+/**
+ * Normalize a DB row so `toolAllowlist` is always `string[] | null`.
+ *
+ * FAIL-OPEN logging: a stored value that is present but cannot be parsed into a
+ * string[] (corrupt JSON, a non-array, non-string elements) degrades to `null` =
+ * "no restriction", so the agent silently gets ALL of the server's tools. Log
+ * one line (server id only, never the contents) so that widening is not silent.
+ */
 function normalizeRow(row: AiMcpServer): AiMcpServer {
-  return { ...row, toolAllowlist: parseToolAllowlist(row.toolAllowlist) };
+  const parsed = parseToolAllowlist(row.toolAllowlist);
+  if (parsed === null && row.toolAllowlist != null) {
+    logger.warn(
+      `Corrupt tool_allowlist for MCP server ${row.id}; ignoring it (no tool restriction applied)`,
+    );
+  }
+  return { ...row, toolAllowlist: parsed };
 }

apps/server/src/database/types/ai-mcp-servers.types.ts

@@ -20,8 +20,15 @@ export interface AiMcpServers {
   // Encrypted JSON of the auth headers. Nullable (a server may need no auth).
   headersEnc: string | null;
   // Optional allowlist of remote tool names to expose; null = expose all.
-  // Stored as jsonb; reads come back as a string[] from the postgres driver.
+  // Stored as jsonb. The postgres driver may return a JSON string for legacy
+  // double-encoded rows; `AiMcpServerRepo` normalizes every read to
+  // `string[] | null` via `parseToolAllowlist`.
   toolAllowlist: string[] | null;
+  // Admin-authored guidance ("how/when to use this server's tools") injected
+  // into the agent system prompt (#180). Unlike `headersEnc` this is NON-secret
+  // and IS returned in admin views/forms. Plain text column (no jsonb). Null =
+  // no guidance. Trusted text — it goes inside the prompt safety sandwich.
+  instructions: string | null;
   enabled: Generated<boolean>;
   createdAt: Generated<Timestamp>;
   updatedAt: Generated<Timestamp>;

apps/server/src/database/types/db.d.ts

@@ -620,10 +620,6 @@ export interface AiChatMessages {
   content: string | null;
   toolCalls: Json | null;
   metadata: Json | null;
-  // Turn lifecycle status (#183): 'streaming' | 'completed' | 'error' |
-  // 'aborted'. NULL on rows written before the status column existed; the app
-  // treats NULL as 'completed' (a settled, pre-status message).
-  status: string | null;
   tsv: string | null;
   createdAt: Generated<Timestamp>;
   updatedAt: Generated<Timestamp>;

apps/server/src/database/utils.ts

@@ -1,3 +1,4 @@
+import { sql, RawBuilder } from 'kysely';
 import { KyselyDB, KyselyTransaction } from './types/kysely.types';
 
 /*
@@ -31,3 +32,35 @@ export function dbOrTx(
     return db; // Use normal database instance
   }
 }
+
+/**
+ * Bind a JS array/object as a `jsonb` column value, working around a postgres
+ * driver double-encoding quirk. THE single implementation — repos that persist
+ * jsonb (`tool_allowlist`, `model_config`, ...) call this instead of re-deriving
+ * the cast.
+ *
+ * THE QUIRK: with the `kysely-postgres-js` / postgres.js driver, casting a bound
+ * parameter straight to `::jsonb` makes the driver infer the param type as jsonb
+ * and JSON-stringify the (already-JSON) text a SECOND time, so the column ends
+ * up holding a jsonb STRING SCALAR (`"[\"a\"]"` / `"{\"k\":1}"`) instead of a
+ * real jsonb array/object. Read paths then see a string, not the structure, and
+ * silently fall back (an allowlist becomes "unrestricted", a model override is
+ * ignored). Forcing the param through `::text` first binds it as text (sent
+ * verbatim); `::jsonb` then parses it into a real array/object. Read-side
+ * parsers repair rows written the old buggy way without a migration.
+ *
+ * Returns `null` for null/undefined and for "empty" values (an empty array, or
+ * an object with no own enumerable keys) — callers treat empty as "clear/unset",
+ * so an empty allowlist/config never round-trips as `[]`/`{}`.
+ */
+export function jsonbBind<T>(
+  value: T | null | undefined,
+): RawBuilder<T> | null {
+  if (value === null || value === undefined) return null;
+  if (Array.isArray(value)) {
+    if (value.length === 0) return null;
+  } else if (typeof value === 'object') {
+    if (Object.keys(value as object).length === 0) return null;
+  }
+  return sql<T>`${JSON.stringify(value)}::text::jsonb`;
+}

apps/server/test/integration/ai-agent-roles-repo.int-spec.ts

@@ -1,4 +1,5 @@
-import { Kysely } from 'kysely';
+import { Kysely, sql } from 'kysely';
+import { randomUUID } from 'node:crypto';
 import { AiAgentRoleRepo } from '@docmost/db/repos/ai-agent-roles/ai-agent-roles.repo';
 import { getTestDb, destroyTestDb, createWorkspace } from './db';
 
@@ -25,8 +26,16 @@ describe('AiAgentRoleRepo isolation + partial unique index [integration]', () =>
   });
 
   it('findById / listByWorkspace exclude soft-deleted rows', async () => {
-    const live = await repo.insert({ workspaceId: w1, name: 'Live', instructions: 'x' });
-    const dead = await repo.insert({ workspaceId: w1, name: 'Dead', instructions: 'x' });
+    const live = await repo.insert({
+      workspaceId: w1,
+      name: 'Live',
+      instructions: 'x',
+    });
+    const dead = await repo.insert({
+      workspaceId: w1,
+      name: 'Dead',
+      instructions: 'x',
+    });
     await repo.softDelete(dead.id, w1);
 
     expect(await repo.findById(live.id, w1)).toBeDefined();
@@ -38,7 +47,11 @@ describe('AiAgentRoleRepo isolation + partial unique index [integration]', () =>
   });
 
   it('findById of a W2 role from W1 context returns undefined (tenant isolation)', async () => {
-    const w2role = await repo.insert({ workspaceId: w2, name: 'W2Role', instructions: 'x' });
+    const w2role = await repo.insert({
+      workspaceId: w2,
+      name: 'W2Role',
+      instructions: 'x',
+    });
 
     expect(await repo.findById(w2role.id, w2)).toBeDefined();
     // Same id, wrong workspace context -> not visible.
@@ -58,21 +71,100 @@ describe('AiAgentRoleRepo isolation + partial unique index [integration]', () =>
   });
 
   it('same name is reusable after softDelete (partial unique index WHERE deleted_at IS NULL)', async () => {
-    const first = await repo.insert({ workspaceId: w1, name: 'Reusable', instructions: 'x' });
+    const first = await repo.insert({
+      workspaceId: w1,
+      name: 'Reusable',
+      instructions: 'x',
+    });
     await repo.softDelete(first.id, w1);
 
     // Now inserting the same name must succeed because the soft-deleted row is
     // excluded from the partial unique index.
-    const second = await repo.insert({ workspaceId: w1, name: 'Reusable', instructions: 'x' });
+    const second = await repo.insert({
+      workspaceId: w1,
+      name: 'Reusable',
+      instructions: 'x',
+    });
     expect(second.id).toBeDefined();
     expect(second.id).not.toBe(first.id);
   });
 
   it('same name in W1 and W2 is allowed (unique is per-workspace)', async () => {
-    const a = await repo.insert({ workspaceId: w1, name: 'CrossTenant', instructions: 'x' });
-    const b = await repo.insert({ workspaceId: w2, name: 'CrossTenant', instructions: 'x' });
+    const a = await repo.insert({
+      workspaceId: w1,
+      name: 'CrossTenant',
+      instructions: 'x',
+    });
+    const b = await repo.insert({
+      workspaceId: w2,
+      name: 'CrossTenant',
+      instructions: 'x',
+    });
     expect(a.id).toBeDefined();
     expect(b.id).toBeDefined();
     expect(a.id).not.toBe(b.id);
   });
+
+  // model_config jsonb round-trip (issue #173 §1): the same double-encoding bug
+  // PR #172 fixed for tool_allowlist lived in jsonbObject. A DB round-trip is the
+  // only way to observe it — the write must land as a real jsonb OBJECT, and a
+  // legacy string-scalar row must self-heal on read (else the model override is
+  // silently dropped and the role falls back to the default model).
+  const jsonbTypeof = async (id: string): Promise<string | null> => {
+    const res = await sql<{ t: string | null }>`
+      SELECT jsonb_typeof(model_config) AS t
+      FROM ai_agent_roles WHERE id = ${id}
+    `.execute(db);
+    return res.rows[0]?.t ?? null;
+  };
+
+  it('insert stores model_config as a jsonb OBJECT and reads it back as an object', async () => {
+    const role = await repo.insert({
+      workspaceId: w1,
+      name: `Model-${randomUUID()}`,
+      instructions: 'x',
+      modelConfig: { driver: 'gemini', chatModel: 'gemini-2.0-flash' },
+    });
+    expect(await jsonbTypeof(role.id)).toBe('object');
+    // The returned row is already normalized to an object.
+    expect(role.modelConfig).toEqual({
+      driver: 'gemini',
+      chatModel: 'gemini-2.0-flash',
+    });
+    const found = await repo.findById(role.id, w1);
+    expect(found?.modelConfig).toEqual({
+      driver: 'gemini',
+      chatModel: 'gemini-2.0-flash',
+    });
+  });
+
+  it('an empty model_config is normalized to null (no override)', async () => {
+    const role = await repo.insert({
+      workspaceId: w1,
+      name: `Empty-${randomUUID()}`,
+      instructions: 'x',
+      modelConfig: {},
+    });
+    // The column is SQL NULL, so jsonb_typeof returns SQL NULL (JS null).
+    expect(await jsonbTypeof(role.id)).toBeNull();
+    expect((await repo.findById(role.id, w1))?.modelConfig).toBeNull();
+  });
+
+  it('repairs a legacy double-encoded (string scalar) model_config on read', async () => {
+    const id = randomUUID();
+    // Seed the corrupt string-scalar shape the old `::jsonb` bind produced.
+    await sql`
+      INSERT INTO ai_agent_roles (id, workspace_id, name, instructions, model_config)
+      VALUES (
+        ${id}, ${w1}, ${`Legacy-${id}`}, 'x',
+        to_jsonb(${'{"driver":"openai","chatModel":"gpt"}'}::text)
+      )
+    `.execute(db);
+    expect(await jsonbTypeof(id)).toBe('string'); // sanity: really corrupt
+
+    expect((await repo.findById(id, w1))?.modelConfig).toEqual({
+      driver: 'openai',
+      chatModel: 'gpt',
+    });
+  });
 });

apps/server/test/integration/ai-chat-message-status.int-spec.ts

@@ -1,270 +0,0 @@
-import { Kysely } from 'kysely';
-import { AiChatMessageRepo } from '@docmost/db/repos/ai-chat/ai-chat-message.repo';
-import {
-  getTestDb,
-  destroyTestDb,
-  createWorkspace,
-  createUser,
-  createChat,
-  createMessage,
-} from './db';
-
-/**
- * Integration coverage for the #183 step-granular durability primitives on
- * AiChatMessageRepo: `update` (in-place patch by id+workspace, bumps updatedAt,
- * returns the row) and `sweepStreaming` (crash recovery: flip dangling
- * 'streaming' rows to 'aborted'). Real SQL against docmost_test, not a mock.
- */
-describe('AiChatMessageRepo.update + sweepStreaming [integration]', () => {
-  let db: Kysely<any>;
-  let repo: AiChatMessageRepo;
-  let workspaceId: string;
-  let otherWorkspaceId: string;
-  let userId: string;
-  let chatId: string;
-  let otherChatId: string;
-
-  beforeAll(async () => {
-    db = getTestDb();
-    repo = new AiChatMessageRepo(db as any);
-    workspaceId = (await createWorkspace(db)).id;
-    otherWorkspaceId = (await createWorkspace(db)).id;
-    userId = (await createUser(db, workspaceId)).id;
-    chatId = (await createChat(db, { workspaceId, creatorId: userId })).id;
-    const otherUser = await createUser(db, otherWorkspaceId);
-    otherChatId = (
-      await createChat(db, {
-        workspaceId: otherWorkspaceId,
-        creatorId: otherUser.id,
-      })
-    ).id;
-  });
-
-  afterAll(async () => {
-    await destroyTestDb();
-  });
-
-  it('update patches content/status/metadata and bumps updatedAt', async () => {
-    const seeded = await repo.insert({
-      chatId,
-      workspaceId,
-      userId,
-      role: 'assistant',
-      content: '',
-      status: 'streaming',
-      metadata: { parts: [] } as never,
-    });
-    const before = seeded.updatedAt;
-    // Ensure a measurable timestamp delta.
-    await new Promise((r) => setTimeout(r, 5));
-
-    const updated = await repo.update(seeded.id, workspaceId, {
-      content: 'final answer',
-      status: 'completed',
-      metadata: { parts: [{ type: 'text', text: 'final answer' }] },
-    });
-
-    expect(updated).toBeDefined();
-    expect(updated!.content).toBe('final answer');
-    expect(updated!.status).toBe('completed');
-    expect((updated!.metadata as any).parts).toHaveLength(1);
-    // The 5ms sleep above guarantees a strictly-later timestamp.
-    expect(new Date(updated!.updatedAt).getTime()).toBeGreaterThan(
-      new Date(before).getTime(),
-    );
-  });
-
-  it('onlyIfStreaming update is a NO-OP once the row is finalized (race guard)', async () => {
-    // Reproduce the step-update-vs-finalize race (#183 review): the row is
-    // finalized to 'completed', then a LATE per-step 'streaming' update lands.
-    // With `onlyIfStreaming` it must match nothing and leave the finalized row
-    // untouched (no clobber back to 'streaming', no lost usage).
-    const seeded = await repo.insert({
-      chatId,
-      workspaceId,
-      userId,
-      role: 'assistant',
-      content: 'partial',
-      status: 'streaming',
-    });
-    // Terminal finalize (unguarded) wins.
-    await repo.update(seeded.id, workspaceId, {
-      content: 'final answer',
-      status: 'completed',
-      metadata: { usage: { totalTokens: 42 } } as never,
-    });
-    // A straggler per-step update arrives AFTER finalize.
-    const late = await repo.update(
-      seeded.id,
-      workspaceId,
-      { content: 'partial', status: 'streaming', metadata: {} as never },
-      { onlyIfStreaming: true },
-    );
-    expect(late).toBeUndefined(); // matched no 'streaming' row -> no-op
-    const rows = await repo.findAllByChat(chatId, workspaceId);
-    const row = rows.find((r) => r.id === seeded.id)!;
-    expect(row.status).toBe('completed'); // NOT clobbered back to streaming
-    expect(row.content).toBe('final answer');
-    expect((row.metadata as any).usage.totalTokens).toBe(42); // usage preserved
-  });
-
-  it('update is workspace-scoped: a foreign workspace id matches nothing', async () => {
-    const seeded = await repo.insert({
-      chatId,
-      workspaceId,
-      userId,
-      role: 'assistant',
-      content: 'orig',
-      status: 'streaming',
-    });
-    const res = await repo.update(seeded.id, otherWorkspaceId, {
-      status: 'completed',
-    });
-    expect(res).toBeUndefined();
-    // The row in the real workspace is untouched.
-    const rows = await repo.findAllByChat(chatId, workspaceId);
-    const stillThere = rows.find((r) => r.id === seeded.id);
-    expect(stillThere!.status).toBe('streaming');
-    // Clean up so it does not pollute the sweep test below.
-    await repo.update(seeded.id, workspaceId, { status: 'completed' });
-  });
-
-  // Backdate a row's updatedAt so it qualifies as a STALE streaming row (the
-  // sweep only flips rows untouched for >10 minutes — a live turn bumps
-  // updatedAt every step, so it would never match).
-  async function backdateUpdatedAt(
-    id: string,
-    minutesAgo: number,
-  ): Promise<void> {
-    await db
-      .updateTable('aiChatMessages')
-      .set({ updatedAt: new Date(Date.now() - minutesAgo * 60 * 1000) })
-      .where('id', '=', id)
-      .execute();
-  }
-
-  it('sweepStreaming flips STALE dangling streaming rows to aborted and counts them', async () => {
-    // Two dangling streaming rows in our workspace + one in another workspace —
-    // all backdated past the staleness threshold so the sweep picks them up.
-    const a = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: 'streaming',
-    });
-    const b = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: 'streaming',
-    });
-    const other = await createMessage(db, {
-      workspaceId: otherWorkspaceId,
-      chatId: otherChatId,
-      role: 'assistant',
-      status: 'streaming',
-    });
-    await backdateUpdatedAt(a.id, 20);
-    await backdateUpdatedAt(b.id, 20);
-    await backdateUpdatedAt(other.id, 20);
-
-    // A settled row must NOT be touched.
-    const done = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: 'completed',
-    });
-    // A legacy NULL-status row must NOT be touched.
-    const legacy = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: null,
-    });
-
-    const swept = await repo.sweepStreaming();
-    // At least the 3 stale streaming rows we created (2 here + 1 in the other ws).
-    expect(swept).toBeGreaterThanOrEqual(3);
-
-    const rows = await repo.findAllByChat(chatId, workspaceId);
-    const byId = new Map(rows.map((r) => [r.id, r]));
-    expect(byId.get(a.id)!.status).toBe('aborted');
-    expect(byId.get(b.id)!.status).toBe('aborted');
-    expect(byId.get(done.id)!.status).toBe('completed');
-    expect(byId.get(legacy.id)!.status).toBeNull();
-
-    // Idempotent: a second sweep finds nothing left in our seeded set.
-    const again = await repo.sweepStreaming();
-    const rows2 = await repo.findAllByChat(chatId, workspaceId);
-    // Our two rows stay aborted regardless of `again`'s global count.
-    expect(rows2.find((r) => r.id === a.id)!.status).toBe('aborted');
-    expect(again).toBeGreaterThanOrEqual(0);
-  });
-
-  it('sweepStreaming does NOT sweep a FRESH streaming row (recency bound, #183 review)', async () => {
-    // A row that is actively streaming (recent updatedAt) must survive the sweep:
-    // a fresh replica's boot-sweep must never abort a turn another replica is
-    // still streaming in a multi-instance deploy.
-    const fresh = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: 'streaming',
-    });
-    // A STALE streaming row created alongside it IS swept — proving the sweep
-    // ran and the only difference is recency.
-    const stale = await createMessage(db, {
-      workspaceId,
-      chatId,
-      role: 'assistant',
-      status: 'streaming',
-    });
-    await backdateUpdatedAt(stale.id, 20);
-
-    await repo.sweepStreaming();
-
-    const rows = await repo.findAllByChat(chatId, workspaceId);
-    const byId = new Map(rows.map((r) => [r.id, r]));
-    // Fresh (recently-updated) streaming row is left untouched...
-    expect(byId.get(fresh.id)!.status).toBe('streaming');
-    // ...while the stale one alongside it was swept to 'aborted'.
-    expect(byId.get(stale.id)!.status).toBe('aborted');
-  });
-
-  it('findAllByChat caps the result, keeping the NEWEST messages in order (#183 review)', async () => {
-    // A dedicated chat so the cap test is independent of the rows above.
-    const cappedChat = (
-      await createChat(db, { workspaceId, creatorId: userId })
-    ).id;
-    const base = Date.now();
-    // Three messages at strictly increasing timestamps.
-    await createMessage(db, {
-      workspaceId,
-      chatId: cappedChat,
-      content: 'm1-oldest',
-      createdAt: new Date(base),
-    });
-    await createMessage(db, {
-      workspaceId,
-      chatId: cappedChat,
-      content: 'm2',
-      createdAt: new Date(base + 1000),
-    });
-    await createMessage(db, {
-      workspaceId,
-      chatId: cappedChat,
-      content: 'm3-newest',
-      createdAt: new Date(base + 2000),
-    });
-
-    // Cap of 2 -> the OLDEST message is dropped; the newest two stay, in
-    // chronological order (oldest -> newest).
-    const capped = await repo.findAllByChat(cappedChat, workspaceId, 2);
-    expect(capped.map((r) => r.content)).toEqual(['m2', 'm3-newest']);
-
-    // Without a cap (well above the row count) all three come back in order.
-    const all = await repo.findAllByChat(cappedChat, workspaceId, 100);
-    expect(all.map((r) => r.content)).toEqual(['m1-oldest', 'm2', 'm3-newest']);
-  });
-});

apps/server/test/integration/ai-mcp-server-repo.int-spec.ts

@@ -0,0 +1,175 @@
+import { Kysely, sql } from 'kysely';
+import { randomUUID } from 'node:crypto';
+import { AiMcpServerRepo } from '@docmost/db/repos/ai-chat/ai-mcp-server.repo';
+import { getTestDb, destroyTestDb, createWorkspace } from './db';
+
+/**
+ * AiMcpServerRepo `tool_allowlist` jsonb round-trip (PR #172 / issue #173 §3).
+ *
+ * The fix under test is a DB round-trip, so a unit test cannot observe it: the
+ * write must land as a real jsonb ARRAY (not a double-encoded string scalar),
+ * and the read must repair any legacy string-scalar rows. The read-side
+ * `parseToolAllowlist` MASKS a write regression (it parses the string back), so
+ * without this integration check, reverting `::text::jsonb` to `::jsonb` would
+ * keep every unit test green while silently corrupting the column again.
+ */
+describe('AiMcpServerRepo tool_allowlist jsonb round-trip [integration]', () => {
+  let db: Kysely<any>;
+  let repo: AiMcpServerRepo;
+  let ws: string;
+
+  beforeAll(async () => {
+    db = getTestDb();
+    repo = new AiMcpServerRepo(db as any);
+    ws = (await createWorkspace(db)).id;
+  });
+
+  afterAll(async () => {
+    await destroyTestDb();
+  });
+
+  const jsonbTypeof = async (id: string): Promise<string | null> => {
+    const res = await sql<{ t: string | null }>`
+      SELECT jsonb_typeof(tool_allowlist) AS t
+      FROM ai_mcp_servers WHERE id = ${id}
+    `.execute(db);
+    return res.rows[0]?.t ?? null;
+  };
+
+  it('insert stores the allowlist as a jsonb ARRAY (not a string scalar)', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+      toolAllowlist: ['search', 'crawl'],
+    });
+
+    // The column holds a real jsonb array — the whole point of ::text::jsonb.
+    expect(await jsonbTypeof(row.id)).toBe('array');
+
+    // And the read returns a genuine string[], not a JSON string.
+    const found = await repo.findById(row.id, ws);
+    expect(found?.toolAllowlist).toEqual(['search', 'crawl']);
+    expect(Array.isArray(found?.toolAllowlist)).toBe(true);
+  });
+
+  it('an empty allowlist is normalized to null (no restriction), not []', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+      toolAllowlist: [],
+    });
+    // The column is SQL NULL, so jsonb_typeof returns SQL NULL (JS null).
+    expect(await jsonbTypeof(row.id)).toBeNull();
+    expect((await repo.findById(row.id, ws))?.toolAllowlist).toBeNull();
+  });
+
+  it('repairs a legacy double-encoded (string scalar) row on read (self-heal)', async () => {
+    // Seed a row whose tool_allowlist is a jsonb STRING SCALAR holding the JSON
+    // text — exactly what the old `::jsonb` double-encoding produced.
+    const id = randomUUID();
+    await sql`
+      INSERT INTO ai_mcp_servers (id, workspace_id, name, transport, url, tool_allowlist)
+      VALUES (
+        ${id}, ${ws}, ${`srv-${id}`}, 'http', 'https://example.com/mcp',
+        to_jsonb(${'["alpha","beta"]'}::text)
+      )
+    `.execute(db);
+
+    // Sanity: the seeded column really IS the corrupt string-scalar shape.
+    expect(await jsonbTypeof(id)).toBe('string');
+
+    // The repo read heals it back to a real string[].
+    expect((await repo.findById(id, ws))?.toolAllowlist).toEqual([
+      'alpha',
+      'beta',
+    ]);
+    const enabled = await repo.listEnabled(ws);
+    const healed = enabled.find((r) => r.id === id);
+    expect(healed?.toolAllowlist).toEqual(['alpha', 'beta']);
+  });
+});
+
+/**
+ * AiMcpServerRepo `instructions` text round-trip (#180). The column is plain
+ * text (no jsonb); blank/whitespace is normalized to null on both insert and
+ * update so an empty guide is never persisted.
+ */
+describe('AiMcpServerRepo instructions round-trip [integration]', () => {
+  let db: Kysely<any>;
+  let repo: AiMcpServerRepo;
+  let ws: string;
+
+  beforeAll(async () => {
+    db = getTestDb();
+    repo = new AiMcpServerRepo(db as any);
+    ws = (await createWorkspace(db)).id;
+  });
+
+  afterAll(async () => {
+    await destroyTestDb();
+  });
+
+  it('insert stores trimmed non-blank instructions and reads them back', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+      instructions: '  Use search for fresh facts.  ',
+    });
+    expect((await repo.findById(row.id, ws))?.instructions).toBe(
+      'Use search for fresh facts.',
+    );
+  });
+
+  it('insert normalizes blank/whitespace instructions to null', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+      instructions: '   ',
+    });
+    expect((await repo.findById(row.id, ws))?.instructions).toBeNull();
+  });
+
+  it('insert with omitted instructions stores null', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+    });
+    expect((await repo.findById(row.id, ws))?.instructions).toBeNull();
+  });
+
+  it('update sets, clears (blank => null), and leaves unchanged when absent', async () => {
+    const row = await repo.insert({
+      workspaceId: ws,
+      name: `srv-${randomUUID()}`,
+      transport: 'http',
+      url: 'https://example.com/mcp',
+      instructions: 'initial guide',
+    });
+
+    // Set a new value.
+    await repo.update(row.id, ws, { instructions: 'updated guide' });
+    expect((await repo.findById(row.id, ws))?.instructions).toBe(
+      'updated guide',
+    );
+
+    // Absent in the patch => unchanged.
+    await repo.update(row.id, ws, { name: 'renamed' });
+    expect((await repo.findById(row.id, ws))?.instructions).toBe(
+      'updated guide',
+    );
+
+    // Blank => cleared to null.
+    await repo.update(row.id, ws, { instructions: '   ' });
+    expect((await repo.findById(row.id, ws))?.instructions).toBeNull();
+  });
+});

apps/server/test/integration/db.ts

@@ -104,8 +104,7 @@ export async function createWorkspace(
       name: overrides.name ?? `ws-${suffix}`,
       // hostname is uniquely constrained; keep it unique per workspace.
       hostname: `host-${suffix}`,
-      settings:
-        overrides.settings === undefined ? null : (overrides.settings as any),
+      settings: overrides.settings === undefined ? null : (overrides.settings as any),
     })
     .returning(['id', 'settings'])
     .executeTakeFirstOrThrow();
@@ -227,37 +226,3 @@ export async function createChat(
     .executeTakeFirstOrThrow();
   return { id: row.id as string };
 }
-
-export async function createMessage(
-  db: Kysely<any>,
-  args: {
-    workspaceId: string;
-    chatId: string;
-    userId?: string | null;
-    role?: string;
-    content?: string | null;
-    status?: string | null;
-    metadata?: unknown;
-    // Explicit timestamp so a test can control message ORDER (the default DB
-    // now() can tie within a millisecond, and the v4 id is not time-ordered).
-    createdAt?: Date;
-  },
-): Promise<{ id: string }> {
-  const id = randomUUID();
-  const row = await db
-    .insertInto('aiChatMessages')
-    .values({
-      id,
-      workspaceId: args.workspaceId,
-      chatId: args.chatId,
-      userId: args.userId ?? null,
-      role: args.role ?? 'assistant',
-      content: args.content ?? null,
-      status: args.status ?? null,
-      metadata: (args.metadata ?? null) as any,
-      ...(args.createdAt ? { createdAt: args.createdAt } : {}),
-    })
-    .returning(['id'])
-    .executeTakeFirstOrThrow();
-  return { id: row.id as string };
-}

packages/editor-ext/src/lib/footnote/footnote-numbering.ts

@@ -1,14 +1,15 @@
-import { EditorState, Plugin, PluginKey } from "@tiptap/pm/state";
-import { Decoration, DecorationSet } from "@tiptap/pm/view";
-import { Node as ProseMirrorNode } from "@tiptap/pm/model";
+import { EditorState, Plugin, PluginKey } from '@tiptap/pm/state';
+import { Decoration, DecorationSet } from '@tiptap/pm/view';
+import { Node as ProseMirrorNode } from '@tiptap/pm/model';
 import {
   FOOTNOTE_DEFINITION_NAME,
   FOOTNOTE_REFERENCE_NAME,
   computeFootnoteNumbers,
-} from "./footnote-util";
+  computeFootnoteRefCounts,
+} from './footnote-util';
 
 export const footnoteNumberingPluginKey = new PluginKey<FootnoteNumberingState>(
-  "footnoteNumbering",
+  'footnoteNumbering',
 );
 
 /**
@@ -21,6 +22,9 @@ export const footnoteNumberingPluginKey = new PluginKey<FootnoteNumberingState>(
 interface FootnoteNumberingState {
   /** referenceId -> 1-based display number, for the current doc. */
   numbers: Map<string, number>;
+  /** referenceId -> number of reference occurrences (>= 1), for the definition's
+   *  multi-backlink UI (#168). */
+  refCounts: Map<string, number>;
   /** Decorations rendering those numbers (refs + definitions). */
   decorations: DecorationSet;
 }
@@ -46,6 +50,7 @@ function buildFootnoteNumberingState(
   doc: ProseMirrorNode,
 ): FootnoteNumberingState {
   const numbers = computeFootnoteNumbers(doc);
+  const refCounts = computeFootnoteRefCounts(doc);
   const decorations: Decoration[] = [];
 
   doc.descendants((node, pos) => {
@@ -54,7 +59,7 @@ function buildFootnoteNumberingState(
       if (num != null) {
         decorations.push(
           Decoration.node(pos, pos + node.nodeSize, {
-            "data-footnote-number": String(num),
+            'data-footnote-number': String(num),
             style: `--footnote-number: "${num}";`,
           }),
         );
@@ -65,7 +70,7 @@ function buildFootnoteNumberingState(
       if (num != null) {
         decorations.push(
           Decoration.node(pos, pos + node.nodeSize, {
-            "data-footnote-number": String(num),
+            'data-footnote-number': String(num),
             style: `--footnote-number: "${num}";`,
           }),
         );
@@ -73,7 +78,11 @@ function buildFootnoteNumberingState(
     }
   });
 
-  return { numbers, decorations: DecorationSet.create(doc, decorations) };
+  return {
+    numbers,
+    refCounts,
+    decorations: DecorationSet.create(doc, decorations),
+  };
 }
 
 /**
@@ -90,6 +99,16 @@ export function getFootnoteNumber(
   return footnoteNumberingPluginKey.getState(state)?.numbers.get(id);
 }
 
+/**
+ * Read the cached reference-occurrence count for `id` (how many `[^id]` links
+ * point at this definition). Drives the definition's multi-backlink UI (#168):
+ * `> 1` renders ↩ a b c …, each scrolling to its own occurrence. Returns 0 when
+ * the plugin is not installed or the id is unknown (caller treats as single).
+ */
+export function getFootnoteRefCount(state: EditorState, id: string): number {
+  return footnoteNumberingPluginKey.getState(state)?.refCounts.get(id) ?? 0;
+}
+
 /**
  * ProseMirror plugin that renders footnote numbers as decorations. It never
  * mutates the document (safe in read-only / share and in collaboration) — it

packages/editor-ext/src/lib/footnote/footnote-reference.ts

@@ -1,14 +1,14 @@
-import { mergeAttributes, Node } from "@tiptap/core";
-import { TextSelection, Transaction } from "@tiptap/pm/state";
-import { ReactNodeViewRenderer } from "@tiptap/react";
+import { mergeAttributes, Node } from '@tiptap/core';
+import { TextSelection, Transaction } from '@tiptap/pm/state';
+import { ReactNodeViewRenderer } from '@tiptap/react';
 import {
   FOOTNOTE_DEFINITION_NAME,
   FOOTNOTE_REFERENCE_NAME,
   FOOTNOTES_LIST_NAME,
   generateFootnoteId,
-} from "./footnote-util";
-import { footnoteNumberingPlugin } from "./footnote-numbering";
-import { footnoteSyncPlugin, footnotePastePlugin } from "./footnote-sync";
+} from './footnote-util';
+import { footnoteNumberingPlugin } from './footnote-numbering';
+import { footnoteSyncPlugin, footnotePastePlugin } from './footnote-sync';
 
 export interface FootnoteReferenceOptions {
   HTMLAttributes: Record<string, any>;
@@ -27,7 +27,7 @@ export interface FootnoteReferenceOptions {
   enableSync?: boolean;
 }
 
-declare module "@tiptap/core" {
+declare module '@tiptap/core' {
   interface Commands<ReturnType> {
     footnote: {
       /**
@@ -42,8 +42,11 @@ declare module "@tiptap/core" {
       removeFootnote: (id: string) => ReturnType;
       /** Scroll to (and focus) a footnote definition by id. */
       scrollToFootnote: (id: string) => ReturnType;
-      /** Scroll to (and select) a footnote reference by id. */
-      scrollToReference: (id: string) => ReturnType;
+      /** Scroll to a footnote reference by id. `index` selects WHICH occurrence
+       *  to scroll to when the id is referenced more than once (reuse, #166):
+       *  0-based, defaults to the first. Used by the definition's multi-backlink
+       *  UI (#168). */
+      scrollToReference: (id: string, index?: number) => ReturnType;
     };
   }
 }
@@ -66,7 +69,7 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
   // Superscript mark's <sup> rule.
   priority: 101,
 
-  group: "inline",
+  group: 'inline',
   inline: true,
   atom: true,
   selectable: true,
@@ -99,10 +102,10 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
     return {
       id: {
         default: null,
-        parseHTML: (element) => element.getAttribute("data-id"),
+        parseHTML: (element) => element.getAttribute('data-id'),
         renderHTML: (attributes) => {
           if (!attributes.id) return {};
-          return { "data-id": attributes.id };
+          return { 'data-id': attributes.id };
         },
       },
     };
@@ -113,7 +116,7 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
       {
         // High priority so the Superscript mark (which also matches <sup>) does
         // not claim a footnote reference and drop it as empty content.
-        tag: "sup[data-footnote-ref]",
+        tag: 'sup[data-footnote-ref]',
         priority: 100,
       },
     ];
@@ -121,9 +124,9 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
 
   renderHTML({ HTMLAttributes }) {
     return [
-      "sup",
+      'sup',
       mergeAttributes(
-        { "data-footnote-ref": "", class: "footnote-ref" },
+        { 'data-footnote-ref': '', class: 'footnote-ref' },
         this.options.HTMLAttributes,
         HTMLAttributes,
       ),
@@ -132,7 +135,7 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
 
   // Plain-text representation (used by generateText / markdown text fallbacks).
   renderText({ node }) {
-    return `[^${node.attrs.id ?? ""}]`;
+    return `[^${node.attrs.id ?? ''}]`;
   },
 
   addNodeView() {
@@ -170,8 +173,10 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
 
           // Make sure the parent accepts an inline atom here.
           const insertPos = selection.from;
-          if (!$from.parent.type.spec.content?.includes("inline") &&
-              !$from.parent.isTextblock) {
+          if (
+            !$from.parent.type.spec.content?.includes('inline') &&
+            !$from.parent.isTextblock
+          ) {
             return false;
           }
 
@@ -311,19 +316,23 @@ export const FootnoteReference = Node.create<FootnoteReferenceOptions>({
             `[data-footnote-def][data-id="${id}"]`,
           ) as HTMLElement | null;
           if (!dom) return false;
-          dom.scrollIntoView({ behavior: "smooth", block: "center" });
+          dom.scrollIntoView({ behavior: 'smooth', block: 'center' });
           return true;
         },
 
       scrollToReference:
-        (id: string) =>
+        (id: string, index = 0) =>
         ({ editor }) => {
           if (!id) return false;
-          const dom = editor.view.dom.querySelector(
+          // querySelectorAll returns the occurrences in document order, so the
+          // index maps 1:1 to the definition's a/b/c backlink (#168). Fall back
+          // to the first match for an out-of-range index.
+          const matches = editor.view.dom.querySelectorAll(
             `sup[data-footnote-ref][data-id="${id}"]`,
-          ) as HTMLElement | null;
+          );
+          const dom = (matches[index] ?? matches[0]) as HTMLElement | undefined;
           if (!dom) return false;
-          dom.scrollIntoView({ behavior: "smooth", block: "center" });
+          dom.scrollIntoView({ behavior: 'smooth', block: 'center' });
           return true;
         },
     };

packages/editor-ext/src/lib/footnote/footnote-util.ts

@@ -1,12 +1,12 @@
-import { Node as ProseMirrorNode } from "@tiptap/pm/model";
+import { Node as ProseMirrorNode } from '@tiptap/pm/model';
 
 /**
  * Node type names for the footnote feature. Centralized so every part of the
  * feature (nodes, plugins, commands) references the same string.
  */
-export const FOOTNOTE_REFERENCE_NAME = "footnoteReference";
-export const FOOTNOTES_LIST_NAME = "footnotesList";
-export const FOOTNOTE_DEFINITION_NAME = "footnoteDefinition";
+export const FOOTNOTE_REFERENCE_NAME = 'footnoteReference';
+export const FOOTNOTES_LIST_NAME = 'footnotesList';
+export const FOOTNOTE_DEFINITION_NAME = 'footnoteDefinition';
 
 /**
  * Generate a uuidv7-style id (time-ordered). Implemented locally so editor-ext
@@ -15,10 +15,10 @@ export const FOOTNOTE_DEFINITION_NAME = "footnoteDefinition";
  */
 export function generateFootnoteId(): string {
   const now = Date.now();
-  const timeHex = now.toString(16).padStart(12, "0");
+  const timeHex = now.toString(16).padStart(12, '0');
 
   const rand = (length: number) => {
-    let out = "";
+    let out = '';
     for (let i = 0; i < length; i++) {
       out += Math.floor(Math.random() * 16).toString(16);
     }
@@ -26,19 +26,19 @@ export function generateFootnoteId(): string {
   };
 
   // version 7 nibble, then variant (8..b) nibble.
-  const versioned = "7" + rand(3);
+  const versioned = '7' + rand(3);
   const variantNibble = (8 + Math.floor(Math.random() * 4)).toString(16);
   const variant = variantNibble + rand(3);
 
   return (
     timeHex.slice(0, 8) +
-    "-" +
+    '-' +
     timeHex.slice(8, 12) +
-    "-" +
+    '-' +
     versioned +
-    "-" +
+    '-' +
     variant +
-    "-" +
+    '-' +
     rand(12)
   );
 }
@@ -89,7 +89,7 @@ export function deriveFootnoteId(
  * Purely deterministic.
  */
 function suffix(n: number): string {
-  let out = "";
+  let out = '';
   let x = n;
   while (x > 0) {
     const rem = (x - 1) % 25;
@@ -131,3 +131,19 @@ export function computeFootnoteNumbers(
   }
   return numbers;
 }
+
+/**
+ * Build a map of `referenceId -> number of reference occurrences` (>= 1) from
+ * document order. After #166 the same id may be referenced multiple times
+ * (reuse: one number, one definition, N forward links); this count drives the
+ * definition's multi-backlink UI (↩ a b c …, #168). Pure function of the doc.
+ */
+export function computeFootnoteRefCounts(
+  doc: ProseMirrorNode,
+): Map<string, number> {
+  const counts = new Map<string, number>();
+  for (const id of collectReferenceIds(doc)) {
+    counts.set(id, (counts.get(id) ?? 0) + 1);
+  }
+  return counts;
+}

packages/mcp/build/client.js

@@ -7,8 +7,7 @@ import { TiptapTransformer } from "@hocuspocus/transformer";
 import * as Y from "yjs";
 import WebSocket from "ws";
 import { convertProseMirrorToMarkdown } from "./lib/markdown-converter.js";
-import { updatePageContentRealtime, replacePageContent, markdownToProseMirror, mutatePageContent, buildCollabWsUrl, assertYjsEncodable, } from "./lib/collaboration.js";
-import { docmostExtensions } from "./lib/docmost-schema.js";
+import { updatePageContentRealtime, replacePageContent, markdownToProseMirror, mutatePageContent, buildCollabWsUrl, assertYjsEncodable, applyDocToFragment, } from "./lib/collaboration.js";
 import { footnoteWarningsField } from "./lib/footnote-analyze.js";
 import { buildPageTree } from "./lib/tree.js";
 import { serializeDocmostMarkdown, parseDocmostMarkdown, } from "./lib/markdown-document.js";
@@ -17,7 +16,7 @@ import { withPageLock } from "./lib/page-lock.js";
 import { applyTextEdits, } from "./lib/json-edit.js";
 import { getCollabToken, performLogin } from "./lib/auth-utils.js";
 import { diffDocs, summarizeChange } from "./lib/diff.js";
-import { applyAnchorInDoc, canAnchorInDoc, } from "./lib/comment-anchor.js";
+import { applyAnchorInDoc, canAnchorInDoc } from "./lib/comment-anchor.js";
 import { blockText, walk, getList, insertMarkerAfter, setCalloutRange, noteItem, mdToInlineNodes, commentsToFootnotes, } from "./lib/transforms.js";
 import vm from "node:vm";
 // Supported image types, kept as two lookup tables so both a local file
@@ -209,7 +208,9 @@ export class DocmostClient {
             // getCollabToken wraps the AxiosError in a plain Error but attaches the
             // HTTP status as `.status`, so detect an auth failure via either the raw
             // AxiosError shape OR the attached status.
-            const axiosStatus = axios.isAxiosError(e) ? e.response?.status : undefined;
+            const axiosStatus = axios.isAxiosError(e)
+                ? e.response?.status
+                : undefined;
             const attachedStatus = e?.status;
             const isAuthError = axiosStatus === 401 ||
                 axiosStatus === 403 ||
@@ -361,14 +362,14 @@ export class DocmostClient {
                             finish(null, mutationResult);
                             return;
                         }
-                        const tempDoc = TiptapTransformer.toYdoc(newDoc, "default", docmostExtensions);
-                        const fragment = ydoc.getXmlFragment("default");
-                        ydoc.transact(() => {
-                            if (fragment.length > 0) {
-                                fragment.delete(0, fragment.length);
-                            }
-                            Y.applyUpdate(ydoc, Y.encodeStateAsUpdate(tempDoc));
-                        });
+                        // Structural diff into the live fragment (issue #152), mirroring
+                        // the main write path: preserves the Yjs ids of unchanged nodes so
+                        // an open editor's cursor is not yanked to the end of the document.
+                        // The previous destructive rewrite (delete-all + applyUpdate of a
+                        // fresh Y.Doc) discarded every node id, so replaceImage — the only
+                        // caller of this method — still reproduced the #152 cursor jump
+                        // (#164). applyDocToFragment runs its own atomic `transact`.
+                        applyDocToFragment(ydoc, newDoc);
                     }
                     catch (e) {
                         finish(e instanceof Error ? e : new Error(String(e)));
@@ -688,7 +689,12 @@ export class DocmostClient {
         if (!inserted) {
             throw new Error(`table_insert_row: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`);
         }
-        return { success: true, table: tableRef, inserted: true, verify: mutation.verify };
+        return {
+            success: true,
+            table: tableRef,
+            inserted: true,
+            verify: mutation.verify,
+        };
     }
     /**
      * Delete the row at 0-based `index` from a table on the LIVE collab document.
@@ -710,7 +716,12 @@ export class DocmostClient {
         if (!deleted) {
             throw new Error(`table_delete_row: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`);
         }
-        return { success: true, table: tableRef, deleted: true, verify: mutation.verify };
+        return {
+            success: true,
+            table: tableRef,
+            deleted: true,
+            verify: mutation.verify,
+        };
     }
     /**
      * Set the plain-text content of cell `[row, col]` (0-based) in a table on the
@@ -734,7 +745,13 @@ export class DocmostClient {
         if (!updated) {
             throw new Error(`table_update_cell: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`);
         }
-        return { success: true, table: tableRef, row, col, verify: mutation.verify };
+        return {
+            success: true,
+            table: tableRef,
+            row,
+            col,
+            verify: mutation.verify,
+        };
     }
     /**
      * Create a new page with title and content.
@@ -829,9 +846,11 @@ export class DocmostClient {
      */
     async updatePage(pageId, content, title) {
         await this.ensureAuthenticated();
-        if (title) {
-            await this.client.post("/pages/update", { pageId, title });
-        }
+        // Write the BODY first, then the title (#159 split-brain). If the collab
+        // body write fails (e.g. a persist timeout), the title must be left
+        // UNTOUCHED so the page never ends up with a new title over its old body.
+        // A title write failing AFTER a successful body is rarer (REST is fast) and
+        // leaves correct content under a stale title — the lesser inconsistency.
         let collabToken = "";
         let mutation;
         try {
@@ -850,6 +869,10 @@ export class DocmostClient {
             }
             throw new Error(`Failed to update page content: ${error.message}`);
         }
+        // Body persisted successfully — now it is safe to set the title.
+        if (title) {
+            await this.client.post("/pages/update", { pageId, title });
+        }
         return {
             success: true,
             modified: true,
@@ -969,7 +992,9 @@ export class DocmostClient {
         if (!node || typeof node !== "object" || typeof node.type !== "string") {
             throw new Error("invalid ProseMirror document: every node must be an object with a string `type`");
         }
-        if ("text" in node && node.type === "text" && typeof node.text !== "string") {
+        if ("text" in node &&
+            node.type === "text" &&
+            typeof node.text !== "string") {
             throw new Error("invalid ProseMirror document: a text node must have a string `text`");
         }
         if (node.marks !== undefined) {
@@ -977,7 +1002,9 @@ export class DocmostClient {
                 throw new Error("invalid ProseMirror document: `marks` must be an array");
             }
             for (const mark of node.marks) {
-                if (!mark || typeof mark !== "object" || typeof mark.type !== "string") {
+                if (!mark ||
+                    typeof mark !== "object" ||
+                    typeof mark.type !== "string") {
                     throw new Error("invalid ProseMirror document: every mark must be an object with a string `type`");
                 }
             }
@@ -1036,11 +1063,14 @@ export class DocmostClient {
         // the markdown link path (which TipTap sanitizes), raw JSON could otherwise
         // inject javascript:/data: link hrefs or media srcs straight into the doc.
         this.validateDocUrls(doc);
+        // Write the BODY first, then the title (#159 split-brain): a failed body
+        // write (e.g. persist timeout) must not leave a new title over the old body.
+        const collabToken = await this.getCollabTokenWithReauth();
+        const mutation = await replacePageContent(pageId, doc, collabToken, this.apiUrl);
+        // Body persisted successfully — now it is safe to set the title.
         if (title) {
             await this.client.post("/pages/update", { pageId, title });
         }
-        const collabToken = await this.getCollabTokenWithReauth();
-        const mutation = await replacePageContent(pageId, doc, collabToken, this.apiUrl);
         return {
             success: true,
             modified: true,
@@ -1057,9 +1087,7 @@ export class DocmostClient {
     async exportPageMarkdown(pageId) {
         await this.ensureAuthenticated();
         const page = await this.getPageRaw(pageId);
-        const body = page.content
-            ? convertProseMirrorToMarkdown(page.content)
-            : "";
+        const body = page.content ? convertProseMirrorToMarkdown(page.content) : "";
         let comments = [];
         try {
             comments = await this.listComments(pageId);
@@ -1293,13 +1321,22 @@ export class DocmostClient {
             replaced = 0;
             const { doc: nd, replaced: r } = replaceNodeById(liveDoc, nodeId, target);
             replaced = r;
-            if (replaced === 0)
-                return null; // no match -> skip the write entirely
+            // 0 matches -> skip the write. >1 matches -> the id is AMBIGUOUS: Docmost
+            // duplicates block ids on copy/paste (and copyPageContent writes them
+            // verbatim), so replacing "the node with id X" would silently clobber
+            // EVERY duplicate (#159). Refuse: skip the write and throw below so the
+            // model re-targets with a more specific anchor instead of corrupting the
+            // page. Only an unambiguous single match is written.
+            if (replaced !== 1)
+                return null;
             return nd;
         });
         if (replaced === 0) {
             throw new Error(`patch_node: no node with id "${nodeId}" found on page ${pageId}`);
         }
+        if (replaced > 1) {
+            throw new Error(`patch_node: id "${nodeId}" is ambiguous — ${replaced} nodes on page ${pageId} share it (block ids are duplicated on copy/paste). Refusing to replace all of them; nothing was changed. Re-target with a more specific anchor.`);
+        }
         return { success: true, replaced, nodeId, verify: mutation.verify };
     }
     /**
@@ -1355,7 +1392,7 @@ export class DocmostClient {
             // markdown/emoji are tolerated only as a strip-and-retry fallback, so a
             // miss usually means the text differs from what's on the page.
             const hint = opts.anchorText
-                ? ' anchorText must be the block\'s literal rendered plain text (no markdown wrappers or emoji); anchorNodeId from get_page_json is more reliable.'
+                ? " anchorText must be the block's literal rendered plain text (no markdown wrappers or emoji); anchorNodeId from get_page_json is more reliable."
                 : "";
             throw new Error(`insert_node: anchor not found (${anchorDesc}) on page ${pageId}.${hint}`);
         }
@@ -1382,13 +1419,21 @@ export class DocmostClient {
             deleted = 0;
             const { doc: nd, deleted: d } = deleteNodeById(liveDoc, nodeId);
             deleted = d;
-            if (deleted === 0)
-                return null; // no match -> skip the write entirely
+            // 0 matches -> skip the write. >1 matches -> the id is AMBIGUOUS (block
+            // ids are duplicated on copy/paste, #159): deleting "the node with id X"
+            // would silently remove EVERY duplicate. Refuse: skip the write and throw
+            // below so the model re-targets. Only an unambiguous single match is
+            // deleted.
+            if (deleted !== 1)
+                return null;
             return nd;
         });
         if (deleted === 0) {
             throw new Error(`delete_node: no node with id "${nodeId}" found on page ${pageId}`);
         }
+        if (deleted > 1) {
+            throw new Error(`delete_node: id "${nodeId}" is ambiguous — ${deleted} nodes on page ${pageId} share it (block ids are duplicated on copy/paste). Refusing to delete all of them; nothing was changed. Re-target with a more specific anchor.`);
+        }
         return { success: true, deleted, nodeId, verify: mutation.verify };
     }
     /** Build the public share URL for a page. */

packages/mcp/src/client.ts

@@ -20,9 +20,9 @@ import {
   mutatePageContent,
   buildCollabWsUrl,
   assertYjsEncodable,
+  applyDocToFragment,
   MutationResult,
 } from "./lib/collaboration.js";
-import { docmostExtensions } from "./lib/docmost-schema.js";
 import { footnoteWarningsField } from "./lib/footnote-analyze.js";
 import { buildPageTree } from "./lib/tree.js";
 import {
@@ -49,10 +49,7 @@ import {
 } from "./lib/json-edit.js";
 import { getCollabToken, performLogin } from "./lib/auth-utils.js";
 import { diffDocs, summarizeChange } from "./lib/diff.js";
-import {
-  applyAnchorInDoc,
-  canAnchorInDoc,
-} from "./lib/comment-anchor.js";
+import { applyAnchorInDoc, canAnchorInDoc } from "./lib/comment-anchor.js";
 import {
   blockText,
   walk,
@@ -305,7 +302,9 @@ export class DocmostClient {
       // getCollabToken wraps the AxiosError in a plain Error but attaches the
       // HTTP status as `.status`, so detect an auth failure via either the raw
       // AxiosError shape OR the attached status.
-      const axiosStatus = axios.isAxiosError(e) ? e.response?.status : undefined;
+      const axiosStatus = axios.isAxiosError(e)
+        ? e.response?.status
+        : undefined;
       const attachedStatus = (e as any)?.status;
       const isAuthError =
         axiosStatus === 401 ||
@@ -479,18 +478,14 @@ export class DocmostClient {
               return;
             }
 
-            const tempDoc = TiptapTransformer.toYdoc(
-              newDoc,
-              "default",
-              docmostExtensions,
-            );
-            const fragment = ydoc.getXmlFragment("default");
-            ydoc.transact(() => {
-              if (fragment.length > 0) {
-                fragment.delete(0, fragment.length);
-              }
-              Y.applyUpdate(ydoc, Y.encodeStateAsUpdate(tempDoc));
-            });
+            // Structural diff into the live fragment (issue #152), mirroring
+            // the main write path: preserves the Yjs ids of unchanged nodes so
+            // an open editor's cursor is not yanked to the end of the document.
+            // The previous destructive rewrite (delete-all + applyUpdate of a
+            // fresh Y.Doc) discarded every node id, so replaceImage — the only
+            // caller of this method — still reproduced the #152 cursor jump
+            // (#164). applyDocToFragment runs its own atomic `transact`.
+            applyDocToFragment(ydoc, newDoc);
           } catch (e) {
             finish(e instanceof Error ? e : new Error(String(e)));
             return;
@@ -601,11 +596,7 @@ export class DocmostClient {
    * sidebar requests and is bounded by that method's 10000-node cap (and skips
    * soft-deleted pages server-side).
    */
-  async listPages(
-    spaceId?: string,
-    limit: number = 50,
-    tree: boolean = false,
-  ) {
+  async listPages(spaceId?: string, limit: number = 50, tree: boolean = false) {
     await this.ensureAuthenticated();
 
     if (tree) {
@@ -884,7 +875,12 @@ export class DocmostClient {
         `table_insert_row: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`,
       );
     }
-    return { success: true, table: tableRef, inserted: true, verify: mutation.verify };
+    return {
+      success: true,
+      table: tableRef,
+      inserted: true,
+      verify: mutation.verify,
+    };
   }
 
   /**
@@ -903,7 +899,11 @@ export class DocmostClient {
       this.apiUrl,
       (liveDoc) => {
         deleted = false;
-        const { doc: nd, deleted: del } = deleteTableRow(liveDoc, tableRef, index);
+        const { doc: nd, deleted: del } = deleteTableRow(
+          liveDoc,
+          tableRef,
+          index,
+        );
         deleted = del;
         if (!deleted) return null; // table not found -> skip the write entirely
         return nd;
@@ -915,7 +915,12 @@ export class DocmostClient {
         `table_delete_row: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`,
       );
     }
-    return { success: true, table: tableRef, deleted: true, verify: mutation.verify };
+    return {
+      success: true,
+      table: tableRef,
+      deleted: true,
+      verify: mutation.verify,
+    };
   }
 
   /**
@@ -960,7 +965,13 @@ export class DocmostClient {
         `table_update_cell: no table found for "${tableRef}" on page ${pageId} (use "#<index>" from get_outline, or a block id inside the table)`,
       );
     }
-    return { success: true, table: tableRef, row, col, verify: mutation.verify };
+    return {
+      success: true,
+      table: tableRef,
+      row,
+      col,
+      verify: mutation.verify,
+    };
   }
 
   /**
@@ -1034,8 +1045,7 @@ export class DocmostClient {
         response = await axios.post(importUrl, form2, {
           headers: {
             ...form2.getHeaders(),
-            Authorization:
-              this.client.defaults.headers.common["Authorization"],
+            Authorization: this.client.defaults.headers.common["Authorization"],
           },
           timeout: 60000,
         });
@@ -1069,10 +1079,11 @@ export class DocmostClient {
   async updatePage(pageId: string, content: string, title?: string) {
     await this.ensureAuthenticated();
 
-    if (title) {
-      await this.client.post("/pages/update", { pageId, title });
-    }
-
+    // Write the BODY first, then the title (#159 split-brain). If the collab
+    // body write fails (e.g. a persist timeout), the title must be left
+    // UNTOUCHED so the page never ends up with a new title over its old body.
+    // A title write failing AFTER a successful body is rarer (REST is fast) and
+    // leaves correct content under a stale title — the lesser inconsistency.
     let collabToken = "";
     let mutation;
     try {
@@ -1099,6 +1110,11 @@ export class DocmostClient {
       throw new Error(`Failed to update page content: ${error.message}`);
     }
 
+    // Body persisted successfully — now it is safe to set the title.
+    if (title) {
+      await this.client.post("/pages/update", { pageId, title });
+    }
+
     return {
       success: true,
       modified: true,
@@ -1173,9 +1189,7 @@ export class DocmostClient {
       for (const mark of node.marks) {
         if (mark && mark.type === "link" && mark.attrs) {
           if (!this.isSafeUrl(mark.attrs.href, "link")) {
-            throw new Error(
-              `unsafe link href rejected: "${mark.attrs.href}"`,
-            );
+            throw new Error(`unsafe link href rejected: "${mark.attrs.href}"`);
           }
         }
       }
@@ -1234,7 +1248,11 @@ export class DocmostClient {
         "invalid ProseMirror document: every node must be an object with a string `type`",
       );
     }
-    if ("text" in node && node.type === "text" && typeof node.text !== "string") {
+    if (
+      "text" in node &&
+      node.type === "text" &&
+      typeof node.text !== "string"
+    ) {
       throw new Error(
         "invalid ProseMirror document: a text node must have a string `text`",
       );
@@ -1246,7 +1264,11 @@ export class DocmostClient {
         );
       }
       for (const mark of node.marks) {
-        if (!mark || typeof mark !== "object" || typeof mark.type !== "string") {
+        if (
+          !mark ||
+          typeof mark !== "object" ||
+          typeof mark.type !== "string"
+        ) {
           throw new Error(
             "invalid ProseMirror document: every mark must be an object with a string `type`",
           );
@@ -1321,10 +1343,8 @@ export class DocmostClient {
     // inject javascript:/data: link hrefs or media srcs straight into the doc.
     this.validateDocUrls(doc);
 
-    if (title) {
-      await this.client.post("/pages/update", { pageId, title });
-    }
-
+    // Write the BODY first, then the title (#159 split-brain): a failed body
+    // write (e.g. persist timeout) must not leave a new title over the old body.
     const collabToken = await this.getCollabTokenWithReauth();
     const mutation = await replacePageContent(
       pageId,
@@ -1333,6 +1353,11 @@ export class DocmostClient {
       this.apiUrl,
     );
 
+    // Body persisted successfully — now it is safe to set the title.
+    if (title) {
+      await this.client.post("/pages/update", { pageId, title });
+    }
+
     return {
       success: true,
       modified: true,
@@ -1350,9 +1375,7 @@ export class DocmostClient {
   async exportPageMarkdown(pageId: string): Promise<string> {
     await this.ensureAuthenticated();
     const page = await this.getPageRaw(pageId);
-    const body = page.content
-      ? convertProseMirrorToMarkdown(page.content)
-      : "";
+    const body = page.content ? convertProseMirrorToMarkdown(page.content) : "";
     let comments: any[] = [];
     try {
       comments = await this.listComments(pageId);
@@ -1566,9 +1589,10 @@ export class DocmostClient {
       pageId,
       applied: results,
       failed,
-      message: (failed?.length ?? 0)
-        ? `Applied ${results?.length ?? 0} edit(s); ${failed!.length} failed (see failed[]). Node ids and formatting preserved.`
-        : "Text edits applied (node ids and formatting preserved).",
+      message:
+        (failed?.length ?? 0)
+          ? `Applied ${results?.length ?? 0} edit(s); ${failed!.length} failed (see failed[]). Node ids and formatting preserved.`
+          : "Text edits applied (node ids and formatting preserved).",
       verify: mutation.verify,
     };
 
@@ -1627,9 +1651,19 @@ export class DocmostClient {
       this.apiUrl,
       (liveDoc) => {
         replaced = 0;
-        const { doc: nd, replaced: r } = replaceNodeById(liveDoc, nodeId, target);
+        const { doc: nd, replaced: r } = replaceNodeById(
+          liveDoc,
+          nodeId,
+          target,
+        );
         replaced = r;
-        if (replaced === 0) return null; // no match -> skip the write entirely
+        // 0 matches -> skip the write. >1 matches -> the id is AMBIGUOUS: Docmost
+        // duplicates block ids on copy/paste (and copyPageContent writes them
+        // verbatim), so replacing "the node with id X" would silently clobber
+        // EVERY duplicate (#159). Refuse: skip the write and throw below so the
+        // model re-targets with a more specific anchor instead of corrupting the
+        // page. Only an unambiguous single match is written.
+        if (replaced !== 1) return null;
         return nd;
       },
     );
@@ -1639,6 +1673,11 @@ export class DocmostClient {
         `patch_node: no node with id "${nodeId}" found on page ${pageId}`,
       );
     }
+    if (replaced > 1) {
+      throw new Error(
+        `patch_node: id "${nodeId}" is ambiguous — ${replaced} nodes on page ${pageId} share it (block ids are duplicated on copy/paste). Refusing to replace all of them; nothing was changed. Re-target with a more specific anchor.`,
+      );
+    }
 
     return { success: true, replaced, nodeId, verify: mutation.verify };
   }
@@ -1707,7 +1746,11 @@ export class DocmostClient {
       this.apiUrl,
       (liveDoc) => {
         inserted = false;
-        const { doc: nd, inserted: ins } = insertNodeRelative(liveDoc, node, opts);
+        const { doc: nd, inserted: ins } = insertNodeRelative(
+          liveDoc,
+          node,
+          opts,
+        );
         inserted = ins;
         if (!inserted) return null; // anchor not found -> skip the write entirely
         return nd;
@@ -1722,7 +1765,7 @@ export class DocmostClient {
       // markdown/emoji are tolerated only as a strip-and-retry fallback, so a
       // miss usually means the text differs from what's on the page.
       const hint = opts.anchorText
-        ? ' anchorText must be the block\'s literal rendered plain text (no markdown wrappers or emoji); anchorNodeId from get_page_json is more reliable.'
+        ? " anchorText must be the block's literal rendered plain text (no markdown wrappers or emoji); anchorNodeId from get_page_json is more reliable."
         : "";
       throw new Error(
         `insert_node: anchor not found (${anchorDesc}) on page ${pageId}.${hint}`,
@@ -1759,7 +1802,12 @@ export class DocmostClient {
         deleted = 0;
         const { doc: nd, deleted: d } = deleteNodeById(liveDoc, nodeId);
         deleted = d;
-        if (deleted === 0) return null; // no match -> skip the write entirely
+        // 0 matches -> skip the write. >1 matches -> the id is AMBIGUOUS (block
+        // ids are duplicated on copy/paste, #159): deleting "the node with id X"
+        // would silently remove EVERY duplicate. Refuse: skip the write and throw
+        // below so the model re-targets. Only an unambiguous single match is
+        // deleted.
+        if (deleted !== 1) return null;
         return nd;
       },
     );
@@ -1769,6 +1817,11 @@ export class DocmostClient {
         `delete_node: no node with id "${nodeId}" found on page ${pageId}`,
       );
     }
+    if (deleted > 1) {
+      throw new Error(
+        `delete_node: id "${nodeId}" is ambiguous — ${deleted} nodes on page ${pageId} share it (block ids are duplicated on copy/paste). Refusing to delete all of them; nothing was changed. Re-target with a more specific anchor.`,
+      );
+    }
 
     return { success: true, deleted, nodeId, verify: mutation.verify };
   }
@@ -2140,7 +2193,11 @@ export class DocmostClient {
    * subtree): pages updated after `since` are scanned and their comments
    * filtered by createdAt > since.
    */
-  async checkNewComments(spaceId: string, since: string, parentPageId?: string) {
+  async checkNewComments(
+    spaceId: string,
+    since: string,
+    parentPageId?: string,
+  ) {
     await this.ensureAuthenticated();
 
     const sinceDate = new Date(since);
@@ -2440,8 +2497,7 @@ export class DocmostClient {
         response = await axios.post(uploadUrl, form2, {
           headers: {
             ...form2.getHeaders(),
-            Authorization:
-              this.client.defaults.headers.common["Authorization"],
+            Authorization: this.client.defaults.headers.common["Authorization"],
           },
           timeout: 60000,
         });
@@ -2528,76 +2584,76 @@ export class DocmostClient {
       collabToken,
       this.apiUrl,
       (liveDoc) => {
-      const doc =
-        liveDoc && liveDoc.type === "doc"
-          ? liveDoc
-          : { type: "doc", content: [] };
-      if (!Array.isArray(doc.content)) doc.content = [];
+        const doc =
+          liveDoc && liveDoc.type === "doc"
+            ? liveDoc
+            : { type: "doc", content: [] };
+        if (!Array.isArray(doc.content)) doc.content = [];
 
-      if (opts.replaceText) {
-        // Ambiguity guard (mirrors editPageText): count matching top-level
-        // blocks first, so a non-unique fragment cannot silently replace the
-        // wrong block (e.g. text that also appears inside a callout/table).
-        const matches = doc.content.filter((b: any) =>
-          blockText(b).includes(opts.replaceText!),
-        );
-        if (matches.length === 0) {
-          throw new Error(`replaceText not found: "${opts.replaceText}"`);
-        }
-        if (matches.length > 1) {
-          throw new Error(
-            `replaceText "${opts.replaceText}" matches ${matches.length} blocks; use a longer unique fragment`,
+        if (opts.replaceText) {
+          // Ambiguity guard (mirrors editPageText): count matching top-level
+          // blocks first, so a non-unique fragment cannot silently replace the
+          // wrong block (e.g. text that also appears inside a callout/table).
+          const matches = doc.content.filter((b: any) =>
+            blockText(b).includes(opts.replaceText!),
           );
-        }
-        const idx = doc.content.findIndex((b: any) =>
-          blockText(b).includes(opts.replaceText!),
-        );
-        // Data-loss guard: replaceText swaps the WHOLE top-level block, so if
-        // the fragment only appears nested inside a container (table, callout,
-        // list, blockquote) the entire structure would be destroyed. Refuse
-        // when the matched block is a container rather than a leaf
-        // paragraph/heading and point the caller at a safer tool.
-        const CONTAINER_TYPES = new Set([
-          "table",
-          "callout",
-          "bulletList",
-          "orderedList",
-          "taskList",
-          "blockquote",
-        ]);
-        const matchedBlock = doc.content[idx];
-        if (matchedBlock && CONTAINER_TYPES.has(matchedBlock.type)) {
-          throw new Error(
-            `replaceText matched a ${matchedBlock.type} container block; replacing it would destroy the whole structure. ` +
-              `Use afterText to insert near it, or update_page_json for surgical edits.`,
+          if (matches.length === 0) {
+            throw new Error(`replaceText not found: "${opts.replaceText}"`);
+          }
+          if (matches.length > 1) {
+            throw new Error(
+              `replaceText "${opts.replaceText}" matches ${matches.length} blocks; use a longer unique fragment`,
+            );
+          }
+          const idx = doc.content.findIndex((b: any) =>
+            blockText(b).includes(opts.replaceText!),
           );
-        }
-        doc.content.splice(idx, 1, node);
-        placement = "replaced";
-      } else if (opts.afterText) {
-        // Ambiguity guard (mirrors editPageText): refuse a non-unique fragment.
-        const matches = doc.content.filter((b: any) =>
-          blockText(b).includes(opts.afterText!),
-        );
-        if (matches.length === 0) {
-          throw new Error(`afterText not found: "${opts.afterText}"`);
-        }
-        if (matches.length > 1) {
-          throw new Error(
-            `afterText "${opts.afterText}" matches ${matches.length} blocks; use a longer unique fragment`,
+          // Data-loss guard: replaceText swaps the WHOLE top-level block, so if
+          // the fragment only appears nested inside a container (table, callout,
+          // list, blockquote) the entire structure would be destroyed. Refuse
+          // when the matched block is a container rather than a leaf
+          // paragraph/heading and point the caller at a safer tool.
+          const CONTAINER_TYPES = new Set([
+            "table",
+            "callout",
+            "bulletList",
+            "orderedList",
+            "taskList",
+            "blockquote",
+          ]);
+          const matchedBlock = doc.content[idx];
+          if (matchedBlock && CONTAINER_TYPES.has(matchedBlock.type)) {
+            throw new Error(
+              `replaceText matched a ${matchedBlock.type} container block; replacing it would destroy the whole structure. ` +
+                `Use afterText to insert near it, or update_page_json for surgical edits.`,
+            );
+          }
+          doc.content.splice(idx, 1, node);
+          placement = "replaced";
+        } else if (opts.afterText) {
+          // Ambiguity guard (mirrors editPageText): refuse a non-unique fragment.
+          const matches = doc.content.filter((b: any) =>
+            blockText(b).includes(opts.afterText!),
           );
+          if (matches.length === 0) {
+            throw new Error(`afterText not found: "${opts.afterText}"`);
+          }
+          if (matches.length > 1) {
+            throw new Error(
+              `afterText "${opts.afterText}" matches ${matches.length} blocks; use a longer unique fragment`,
+            );
+          }
+          const idx = doc.content.findIndex((b: any) =>
+            blockText(b).includes(opts.afterText!),
+          );
+          doc.content.splice(idx + 1, 0, node);
+          placement = "after";
+        } else {
+          doc.content.push(node);
+          placement = "appended";
         }
-        const idx = doc.content.findIndex((b: any) =>
-          blockText(b).includes(opts.afterText!),
-        );
-        doc.content.splice(idx + 1, 0, node);
-        placement = "after";
-      } else {
-        doc.content.push(node);
-        placement = "appended";
-      }
 
-      return doc;
+        return doc;
       },
     );
 
@@ -2854,8 +2910,7 @@ export class DocmostClient {
   async diffPageVersions(pageId: string, from?: string, to?: string) {
     await this.ensureAuthenticated();
 
-    const isCurrent = (v?: string) =>
-      v == null || v === "" || v === "current";
+    const isCurrent = (v?: string) => v == null || v === "" || v === "current";
 
     const resolveSide = async (
       v?: string,
@@ -2976,7 +3031,9 @@ export class DocmostClient {
         throw new Error(`transform did not compile: ${e?.message ?? e}`);
       }
       if (typeof fn !== "function") {
-        throw new Error("transform must evaluate to a function (doc, ctx) => doc");
+        throw new Error(
+          "transform must evaluate to a function (doc, ctx) => doc",
+        );
       }
       const result = vm.runInNewContext(
         "f(d, c)",

packages/mcp/test/unit/comment-cursor-stability.test.mjs

@@ -162,3 +162,70 @@ test("assertYjsEncodable rejects an un-hydratable doc at preview time (fromJSON
     /Failed to encode document to Yjs/,
   );
 });
+
+// Issue #164: `replaceImage` went through `mutateLiveContentUnlocked`, which
+// (unlike the main write path fixed in #152) still deleted the whole fragment
+// and re-applied a fresh Y.Doc — discarding every node id, so an open editor's
+// cursor jumped to the document end on an image swap. That method now uses the
+// same `applyDocToFragment`, so a sibling paragraph's cursor anchor survives an
+// image `src`/`attachmentId` replacement. These exercise that routine on the
+// image shapes `replaceImage` produces (top-level and nested in a callout).
+
+const image = (attachmentId, src) => ({
+  type: "image",
+  attrs: { attachmentId, src, width: "640", align: "center" },
+});
+
+test("replacing a top-level image keeps a sibling paragraph's cursor anchor (#164)", () => {
+  const ydoc = new Y.Doc();
+  applyDocToFragment(
+    ydoc,
+    doc(para("Caption above"), image("att-old", "/files/old.png")),
+  );
+
+  // The user's cursor sits in the (unchanged) caption paragraph.
+  const relPos = Y.createRelativePositionFromTypeIndex(paragraphText(ydoc, 0), 7);
+
+  // Agent repoints the image to a freshly uploaded attachment (new id + src).
+  applyDocToFragment(
+    ydoc,
+    doc(para("Caption above"), image("att-new", "/files/new.png")),
+  );
+
+  const abs = Y.createAbsolutePositionFromRelativePosition(relPos, ydoc);
+  assert.notEqual(abs, null, "the caption cursor anchor must still resolve");
+  assert.equal(abs.index, 7, "the cursor must stay at the same offset");
+  // The swap actually landed: the image now carries the new attachment id/src.
+  const img = ydoc.getXmlFragment("default").get(1);
+  assert.equal(img.nodeName, "image");
+  assert.equal(img.getAttribute("attachmentId"), "att-new");
+  assert.equal(img.getAttribute("src"), "/files/new.png");
+});
+
+test("replacing an image nested in a callout keeps an outer paragraph's anchor (#164)", () => {
+  const callout = (attachmentId, src) => ({
+    type: "callout",
+    attrs: { type: "info" },
+    content: [image(attachmentId, src)],
+  });
+  const ydoc = new Y.Doc();
+  applyDocToFragment(
+    ydoc,
+    doc(para("Intro paragraph"), callout("att-old", "/files/old.png")),
+  );
+
+  const relPos = Y.createRelativePositionFromTypeIndex(paragraphText(ydoc, 0), 5);
+
+  applyDocToFragment(
+    ydoc,
+    doc(para("Intro paragraph"), callout("att-new", "/files/new.png")),
+  );
+
+  const abs = Y.createAbsolutePositionFromRelativePosition(relPos, ydoc);
+  assert.notEqual(abs, null, "the outer paragraph anchor must still resolve");
+  assert.equal(abs.index, 5, "the cursor must stay at the same offset");
+  // The nested image was repointed.
+  const calloutEl = ydoc.getXmlFragment("default").get(1);
+  const img = calloutEl.get(0);
+  assert.equal(img.getAttribute("attachmentId"), "att-new");
+});