2026-06-20 20:34:44 +03:00
46 changed files with 2042 additions and 189 deletions
--- a/apps/client/src/features/editor/components/page-embed/page-embed-ancestry-context.tsx
+++ b/apps/client/src/features/editor/components/page-embed/page-embed-ancestry-context.tsx
@@ -0,0 +1,53 @@
+import React, { createContext, useContext, useMemo } from "react";
+
+/** Hard cap on nesting depth for whole-page embeds (cycle/runaway guard). */
+export const PAGE_EMBED_MAX_DEPTH = 5;
+
+type AncestryValue = {
+  /** sourcePageIds of every ancestor pageEmbed up the render tree. */
+  chain: string[];
+  /** Includes the host page id so a top-level self-embed is also caught. */
+  hostPageId: string | null;
+};
+
+const PageEmbedAncestryContext = createContext<AncestryValue>({
+  chain: [],
+  hostPageId: null,
+});
+
+/**
+ * Carries the ancestor `sourcePageId` chain down the nested read-only editors.
+ * The node view reads it to detect cycles (current id already in the chain) and
+ * to enforce a hard depth limit before mounting a deeper nested editor.
+ */
+export function PageEmbedAncestryProvider({
+  sourcePageId,
+  hostPageId,
+  children,
+}: {
+  sourcePageId?: string | null;
+  hostPageId?: string | null;
+  children: React.ReactNode;
+}) {
+  const parent = useContext(PageEmbedAncestryContext);
+  const value = useMemo<AncestryValue>(() => {
+    const nextHost = parent.hostPageId ?? hostPageId ?? null;
+    if (!sourcePageId) {
+      return { chain: parent.chain, hostPageId: nextHost };
+    }
+    return {
+      chain: [...parent.chain, sourcePageId],
+      hostPageId: nextHost,
+    };
+  }, [parent, sourcePageId, hostPageId]);
+
+  return (
+    <PageEmbedAncestryContext.Provider value={value}>
+      {children}
+    </PageEmbedAncestryContext.Provider>
+  );
+}
+
+export function usePageEmbedAncestry() {
+  return useContext(PageEmbedAncestryContext);
+}
--- a/apps/client/src/features/editor/components/page-embed/page-embed-content.tsx
+++ b/apps/client/src/features/editor/components/page-embed/page-embed-content.tsx
@@ -0,0 +1,49 @@
+import { EditorProvider } from "@tiptap/react";
+import { useMemo } from "react";
+import { mainExtensions } from "@/features/editor/extensions/extensions";
+import { UniqueID } from "@docmost/editor-ext";
+
+type Props = {
+  content: unknown;
+};
+
+/**
+ * Read-only nested renderer for embedded whole-page content. Same pattern as
+ * the transclusion read-only renderer: drop uniqueID/globalDragHandle, never
+ * write back, and isolate pointer/drag events from the host editor. Nested
+ * `pageEmbed`/`transclusionReference` nodes inside the content render with
+ * their own views (the cycle/depth guard lives in the node view itself).
+ */
+export default function PageEmbedContent({ content }: Props) {
+  const extensions = useMemo(() => {
+    const filtered = mainExtensions.filter(
+      (e: any) => e.name !== "uniqueID" && e.name !== "globalDragHandle",
+    );
+    return [
+      ...filtered,
+      UniqueID.configure({
+        types: ["heading", "paragraph", "transclusionSource"],
+        updateDocument: false,
+      }),
+    ];
+  }, []);
+
+  const stop = (e: React.SyntheticEvent) => e.stopPropagation();
+
+  return (
+    <div
+      onMouseDown={stop}
+      onClick={stop}
+      onDragStart={stop}
+      onDragOver={stop}
+      onDrop={stop}
+    >
+      <EditorProvider
+        editable={false}
+        immediatelyRender={true}
+        extensions={extensions}
+        content={content as any}
+      />
+    </div>
+  );
+}
--- a/apps/client/src/features/editor/components/page-embed/page-embed-lookup-context.tsx
+++ b/apps/client/src/features/editor/components/page-embed/page-embed-lookup-context.tsx
@@ -0,0 +1,162 @@
+import React, {
+  createContext,
+  useCallback,
+  useContext,
+  useEffect,
+  useMemo,
+  useRef,
+  useState,
+} from "react";
+import { lookupTemplate } from "@/features/page-embed/services/page-embed-api";
+import type { PageTemplateLookup } from "@/features/page-embed/types/page-embed.types";
+
+type ContextValue = {
+  subscribe: (s: {
+    sourcePageId: string;
+    setResult: (r: PageTemplateLookup) => void;
+  }) => () => void;
+  refresh: (sourcePageId: string) => Promise<void>;
+};
+
+const PageEmbedLookupContext = createContext<ContextValue | null>(null);
+
+/**
+ * Batching/de-dup lookup context for whole-page embeds (pageEmbed). Mirrors the
+ * transclusion lookup context but keys purely on `sourcePageId`. On public
+ * shares there is no lookup in MVP, so the context simply isn't mounted (the
+ * node view renders a placeholder when the context is absent).
+ */
+export function PageEmbedLookupProvider({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  const subscribersRef = useRef(new Map<string, Array<(r: PageTemplateLookup) => void>>());
+  const queueRef = useRef(new Set<string>());
+  const tickRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const resultCacheRef = useRef(new Map<string, PageTemplateLookup>());
+  const inFlightRef = useRef(new Set<string>());
+  const pendingRef = useRef(new Map<string, Array<() => void>>());
+
+  const flush = useCallback(async () => {
+    tickRef.current = null;
+    const ids = Array.from(queueRef.current);
+    queueRef.current.clear();
+    if (ids.length === 0) return;
+
+    for (const id of ids) inFlightRef.current.add(id);
+
+    const resolveWaiters = (id: string) => {
+      const waiters = pendingRef.current.get(id);
+      if (!waiters) return;
+      pendingRef.current.delete(id);
+      for (const w of waiters) w();
+    };
+
+    try {
+      const { items } = await lookupTemplate({ sourcePageIds: ids });
+      for (const r of items) {
+        resultCacheRef.current.set(r.sourcePageId, r);
+        inFlightRef.current.delete(r.sourcePageId);
+        const subs = subscribersRef.current.get(r.sourcePageId);
+        if (subs) {
+          for (const set of subs) set(r);
+        }
+        resolveWaiters(r.sourcePageId);
+      }
+    } catch (err) {
+      // Surface the failure: errors must never be swallowed silently.
+      console.error("[pageEmbed] template lookup failed", err);
+      for (const id of ids) {
+        inFlightRef.current.delete(id);
+        resolveWaiters(id);
+      }
+    }
+  }, []);
+
+  const enqueue = useCallback(
+    (id: string) => {
+      queueRef.current.add(id);
+      if (tickRef.current === null) {
+        tickRef.current = setTimeout(flush, 10);
+      }
+    },
+    [flush],
+  );
+
+  const subscribe = useCallback<ContextValue["subscribe"]>(
+    ({ sourcePageId, setResult }) => {
+      const list = subscribersRef.current.get(sourcePageId) ?? [];
+      list.push(setResult);
+      subscribersRef.current.set(sourcePageId, list);
+
+      const cached = resultCacheRef.current.get(sourcePageId);
+      if (cached) {
+        setResult(cached);
+      } else if (!inFlightRef.current.has(sourcePageId)) {
+        enqueue(sourcePageId);
+      }
+
+      return () => {
+        const cur = subscribersRef.current.get(sourcePageId) ?? [];
+        const next = cur.filter((x) => x !== setResult);
+        if (next.length === 0) subscribersRef.current.delete(sourcePageId);
+        else subscribersRef.current.set(sourcePageId, next);
+      };
+    },
+    [enqueue],
+  );
+
+  const refresh = useCallback<ContextValue["refresh"]>(
+    (sourcePageId) =>
+      new Promise<void>((resolve) => {
+        resultCacheRef.current.delete(sourcePageId);
+        inFlightRef.current.delete(sourcePageId);
+        const waiters = pendingRef.current.get(sourcePageId) ?? [];
+        waiters.push(resolve);
+        pendingRef.current.set(sourcePageId, waiters);
+        enqueue(sourcePageId);
+      }),
+    [enqueue],
+  );
+
+  useEffect(
+    () => () => {
+      if (tickRef.current) clearTimeout(tickRef.current);
+    },
+    [],
+  );
+
+  const value = useMemo<ContextValue>(
+    () => ({ subscribe, refresh }),
+    [subscribe, refresh],
+  );
+
+  return (
+    <PageEmbedLookupContext.Provider value={value}>
+      {children}
+    </PageEmbedLookupContext.Provider>
+  );
+}
+
+export function usePageEmbedLookup(sourcePageId: string | null | undefined): {
+  result: PageTemplateLookup | null;
+  refresh: () => Promise<void>;
+  available: boolean;
+} {
+  const ctx = useContext(PageEmbedLookupContext);
+  const [result, setResult] = useState<PageTemplateLookup | null>(null);
+
+  useEffect(() => {
+    if (!ctx || !sourcePageId) return;
+    const unsubscribe = ctx.subscribe({ sourcePageId, setResult });
+    return unsubscribe;
+  }, [ctx, sourcePageId]);
+
+  const refresh = useCallback(async () => {
+    if (!ctx || !sourcePageId) return;
+    await ctx.refresh(sourcePageId);
+  }, [ctx, sourcePageId]);
+
+  return { result, refresh, available: Boolean(ctx) };
+}
--- a/apps/client/src/features/editor/components/page-embed/page-embed-picker.tsx
+++ b/apps/client/src/features/editor/components/page-embed/page-embed-picker.tsx
@@ -0,0 +1,117 @@
+import { useEffect, useRef, useState } from "react";
+import { Modal, ScrollArea, TextInput, Text, UnstyledButton, Group } from "@mantine/core";
+import { useTranslation } from "react-i18next";
+import { useQuery } from "@tanstack/react-query";
+import { IconFileText, IconSearch } from "@tabler/icons-react";
+import type { Editor, Range } from "@tiptap/core";
+import { searchSuggestions } from "@/features/search/services/search-service";
+import type { IPage } from "@/features/page/types/page.types";
+
+export const PAGE_EMBED_PICKER_EVENT = "open-page-embed-picker";
+
+type PickerDetail = {
+  editor: Editor;
+  range: Range;
+  /** Host page id, used to forbid self-embed in the picker. */
+  hostPageId?: string;
+};
+
+/**
+ * Modal page picker for inserting a `pageEmbed`. Queries search-suggestions
+ * with `onlyTemplates` so only template-flagged pages are offered. Forbids
+ * selecting the current (host) page (self-embed guard at insertion time).
+ * Mounted once per editor; opened via a CustomEvent dispatched by the slash
+ * command item.
+ */
+export default function PageEmbedPicker() {
+  const { t } = useTranslation();
+  const [opened, setOpened] = useState(false);
+  const [query, setQuery] = useState("");
+  const detailRef = useRef<PickerDetail | null>(null);
+
+  useEffect(() => {
+    const handler = (e: Event) => {
+      const detail = (e as CustomEvent<PickerDetail>).detail;
+      if (!detail?.editor) return;
+      detailRef.current = detail;
+      setQuery("");
+      setOpened(true);
+    };
+    document.addEventListener(PAGE_EMBED_PICKER_EVENT, handler);
+    return () => document.removeEventListener(PAGE_EMBED_PICKER_EVENT, handler);
+  }, []);
+
+  const { data, isFetching } = useQuery({
+    queryKey: ["page-embed-template-picker", query],
+    queryFn: () =>
+      searchSuggestions({
+        query,
+        includePages: true,
+        onlyTemplates: true,
+        limit: 20,
+      }),
+    enabled: opened,
+    staleTime: 30 * 1000,
+  });
+
+  const hostPageId = detailRef.current?.hostPageId;
+  const pages = ((data?.pages ?? []) as IPage[]).filter(
+    (p) => p && p.id !== hostPageId,
+  );
+
+  const handleSelect = (page: IPage) => {
+    const detail = detailRef.current;
+    if (!detail) return;
+    const { editor, range } = detail;
+    editor
+      .chain()
+      .focus()
+      .deleteRange(range)
+      .insertPageEmbed({ sourcePageId: page.id })
+      .run();
+    setOpened(false);
+  };
+
+  return (
+    <Modal
+      opened={opened}
+      onClose={() => setOpened(false)}
+      title={t("Embed page")}
+      size="md"
+    >
+      <TextInput
+        placeholder={t("Search templates...")}
+        leftSection={<IconSearch size={16} />}
+        value={query}
+        onChange={(e) => setQuery(e.currentTarget.value)}
+        autoFocus
+        mb="sm"
+      />
+      <ScrollArea.Autosize mah={320}>
+        {pages.length === 0 && !isFetching && (
+          <Text size="sm" c="dimmed" ta="center" py="md">
+            {t("No templates found")}
+          </Text>
+        )}
+        {pages.map((page) => (
+          <UnstyledButton
+            key={page.id}
+            onClick={() => handleSelect(page)}
+            style={{ display: "block", width: "100%", padding: "8px 4px" }}
+          >
+            <Group gap="xs" wrap="nowrap">
+              {page.icon ? (
+                <span>{page.icon}</span>
+              ) : (
+                <IconFileText size={16} />
+              )}
+              <Text size="sm" truncate>
+                {page.title || t("Untitled")}
+              </Text>
+            </Group>
+          </UnstyledButton>
+        ))}
+      </ScrollArea.Autosize>
+    </Modal>
+  );
+}
--- a/apps/client/src/features/editor/components/page-embed/page-embed-view.tsx
+++ b/apps/client/src/features/editor/components/page-embed/page-embed-view.tsx
@@ -0,0 +1,253 @@
+import { NodeViewProps, NodeViewWrapper } from "@tiptap/react";
+import { ActionIcon, Menu, Tooltip } from "@mantine/core";
+import {
+  IconAlertTriangle,
+  IconArrowsMaximize,
+  IconDots,
+  IconExternalLink,
+  IconEyeOff,
+  IconInfoCircle,
+  IconRefresh,
+  IconRepeat,
+  IconTrash,
+} from "@tabler/icons-react";
+import { useState } from "react";
+import { Link } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+import { ErrorBoundary } from "react-error-boundary";
+import { buildPageUrl } from "@/features/page/page.utils.ts";
+import classes from "../transclusion/transclusion.module.css";
+import { usePageEmbedLookup } from "./page-embed-lookup-context";
+import {
+  PageEmbedAncestryProvider,
+  usePageEmbedAncestry,
+  PAGE_EMBED_MAX_DEPTH,
+} from "./page-embed-ancestry-context";
+import PageEmbedContent from "./page-embed-content";
+
+function Placeholder({
+  icon,
+  label,
+}: {
+  icon: React.ReactNode;
+  label: string;
+}) {
+  return (
+    <div className={classes.placeholder}>
+      <span className={classes.placeholderIcon}>{icon}</span>
+      <span>{label}</span>
+    </div>
+  );
+}
+
+export default function PageEmbedView(props: NodeViewProps) {
+  const isEditable = props.editor.isEditable;
+  const sourcePageId: string | null = props.node.attrs.sourcePageId ?? null;
+  const [openMenus, setOpenMenus] = useState(0);
+  const trackOpen = (open: boolean) =>
+    setOpenMenus((n) => Math.max(0, n + (open ? 1 : -1)));
+
+  return (
+    <NodeViewWrapper
+      className={classes.includeWrap}
+      data-editable={isEditable ? "true" : "false"}
+      data-focused={isEditable && props.selected ? "true" : "false"}
+      data-menu-open={openMenus > 0 ? "true" : "false"}
+      contentEditable={false}
+    >
+      <ErrorBoundary
+        resetKeys={[sourcePageId]}
+        onError={(err) =>
+          // Never swallow: log the full error with the offending source id.
+          console.error("[pageEmbed] render error", { sourcePageId, err })
+        }
+        fallback={
+          <Placeholder
+            icon={<IconAlertTriangle size={18} stroke={1.6} />}
+            label="Failed to load this embedded page"
+          />
+        }
+      >
+        <PageEmbedBody {...props} trackOpen={trackOpen} />
+      </ErrorBoundary>
+    </NodeViewWrapper>
+  );
+}
+
+function PageEmbedBody({
+  editor,
+  node,
+  deleteNode,
+  trackOpen,
+}: NodeViewProps & { trackOpen: (open: boolean) => void }) {
+  const { t } = useTranslation();
+  const sourcePageId: string | null = node.attrs.sourcePageId ?? null;
+  const isEditable = editor.isEditable;
+  const ancestry = usePageEmbedAncestry();
+
+  // @ts-ignore - editor.storage.pageId is set by the host editor
+  const hostPageId: string | undefined = editor.storage?.pageId;
+
+  const { result, refresh, available } = usePageEmbedLookup(sourcePageId);
+  const [refreshing, setRefreshing] = useState(false);
+  const handleRefresh = async () => {
+    setRefreshing(true);
+    try {
+      await refresh();
+    } finally {
+      setRefreshing(false);
+    }
+  };
+
+  // --- Cycle / depth guard (evaluated before any lookup is rendered) ---------
+  // Self-embed or a source already present in the ancestor chain → cycle.
+  const isCycle =
+    !!sourcePageId &&
+    (ancestry.chain.includes(sourcePageId) ||
+      ancestry.hostPageId === sourcePageId);
+  const isTooDeep = ancestry.chain.length >= PAGE_EMBED_MAX_DEPTH;
+
+  const sourceTitle =
+    result && !("status" in result) ? result.title : null;
+  const sourceIcon = result && !("status" in result) ? result.icon : null;
+  // The app routes pages by slugId, not the raw UUID. Build the link from the
+  // resolved slugId (the `/p/:pageSlug` route redirects to the full URL).
+  const sourceSlugId =
+    result && !("status" in result) ? result.slugId : null;
+  const sourceHref = sourceSlugId
+    ? buildPageUrl(undefined, sourceSlugId, sourceTitle ?? undefined)
+    : null;
+
+  const controls = isEditable ? (
+    <div
+      className={classes.includeControls}
+      contentEditable={false}
+      onMouseDown={(e) => e.preventDefault()}
+    >
+      <Tooltip label={t("Refresh")}>
+        <ActionIcon
+          variant="subtle"
+          color="gray"
+          size="sm"
+          onClick={handleRefresh}
+          loading={refreshing}
+          disabled={!sourcePageId}
+        >
+          <IconRefresh size={14} />
+        </ActionIcon>
+      </Tooltip>
+      {sourceHref && (
+        <Tooltip label={t("Open source page")}>
+          <ActionIcon
+            component={Link}
+            to={sourceHref}
+            variant="subtle"
+            color="gray"
+            size="sm"
+            style={{ textDecoration: "none", borderBottom: "none" }}
+          >
+            <IconExternalLink size={14} />
+          </ActionIcon>
+        </Tooltip>
+      )}
+      <Menu position="bottom-end" withinPortal onChange={trackOpen}>
+        <Menu.Target>
+          <ActionIcon variant="subtle" color="gray" size="sm">
+            <IconDots size={14} />
+          </ActionIcon>
+        </Menu.Target>
+        <Menu.Dropdown>
+          <Menu.Item
+            color="red"
+            leftSection={<IconTrash size={14} />}
+            onClick={() => deleteNode()}
+          >
+            {t("Remove from page")}
+          </Menu.Item>
+        </Menu.Dropdown>
+      </Menu>
+    </div>
+  ) : null;
+
+  const header =
+    sourceTitle || sourceIcon ? (
+      <div className={classes.transclusionBadge}>
+        {sourceIcon ? `${sourceIcon} ` : <IconArrowsMaximize size={12} />}
+        {sourceHref ? (
+          <Link
+            to={sourceHref}
+            style={{ borderBottom: "none", textDecoration: "none" }}
+          >
+            {sourceTitle || t("Untitled")}
+          </Link>
+        ) : (
+          sourceTitle || t("Untitled")
+        )}
+      </div>
+    ) : null;
+
+  let body: React.ReactNode;
+  if (!sourcePageId) {
+    body = (
+      <Placeholder
+        icon={<IconInfoCircle size={18} stroke={1.6} />}
+        label={t("No page selected")}
+      />
+    );
+  } else if (isCycle) {
+    body = (
+      <Placeholder
+        icon={<IconRepeat size={18} stroke={1.6} />}
+        label={t("Circular embed: this page is already shown above")}
+      />
+    );
+  } else if (isTooDeep) {
+    body = (
+      <Placeholder
+        icon={<IconRepeat size={18} stroke={1.6} />}
+        label={t("Embed nesting limit reached")}
+      />
+    );
+  } else if (!available) {
+    // No lookup context (e.g. public share) → placeholder, no fetch in MVP.
+    body = (
+      <Placeholder
+        icon={<IconEyeOff size={18} stroke={1.6} />}
+        label={t("Embedded page is not available here")}
+      />
+    );
+  } else if (!result) {
+    body = <div style={{ minHeight: 24 }} />;
+  } else if (!("status" in result)) {
+    body = (
+      <PageEmbedAncestryProvider
+        sourcePageId={sourcePageId}
+        hostPageId={hostPageId}
+      >
+        <PageEmbedContent content={result.content} />
+      </PageEmbedAncestryProvider>
+    );
+  } else if (result.status === "no_access") {
+    body = (
+      <Placeholder
+        icon={<IconEyeOff size={18} stroke={1.6} />}
+        label={t("You don't have access to this page")}
+      />
+    );
+  } else {
+    body = (
+      <Placeholder
+        icon={<IconInfoCircle size={18} stroke={1.6} />}
+        label={t("The embedded page no longer exists")}
+      />
+    );
+  }
+
+  return (
+    <>
+      {controls}
+      {header}
+      {body}
+    </>
+  );
+}
--- a/apps/client/src/features/editor/components/slash-menu/menu-items.ts
+++ b/apps/client/src/features/editor/components/slash-menu/menu-items.ts
@@ -28,7 +28,9 @@ import {
  IconTag,
  IconMoodSmile,
  IconRotate2,
+  IconArrowsMaximize,
 } from "@tabler/icons-react";
+import { PAGE_EMBED_PICKER_EVENT } from "@/features/editor/components/page-embed/page-embed-picker";
 import {
  CommandProps,
  SlashMenuGroupedItemsType,
@@ -535,6 +537,29 @@ const CommandGroups: SlashMenuGroupedItemsType = {
          .run();
      },
    },
+    {
+      title: "Embed page",
+      description: "Insert a live, read-only copy of another page.",
+      searchTerms: [
+        "template",
+        "embed",
+        "embed page",
+        "page",
+        "live",
+        "include",
+        "reuse",
+      ],
+      icon: IconArrowsMaximize,
+      command: ({ editor, range }: CommandProps) => {
+        // @ts-ignore - editor.storage.pageId is set by the host editor
+        const hostPageId: string | undefined = editor.storage?.pageId;
+        document.dispatchEvent(
+          new CustomEvent(PAGE_EMBED_PICKER_EVENT, {
+            detail: { editor, range, hostPageId },
+          }),
+        );
+      },
+    },
    {
      title: "2 Columns",
      description: "Split content into two columns.",
--- a/apps/client/src/features/editor/extensions/extensions.ts
+++ b/apps/client/src/features/editor/extensions/extensions.ts
@@ -60,6 +60,7 @@ import {
  Status,
  TransclusionSource,
  TransclusionReference,
+  PageEmbed,
  TableView,
 } from "@docmost/editor-ext";
 import {
@@ -91,6 +92,7 @@ import PdfView from "@/features/editor/components/pdf/pdf-view.tsx";
 import SubpagesView from "@/features/editor/components/subpages/subpages-view.tsx";
 import TransclusionView from "@/features/editor/components/transclusion/transclusion-view.tsx";
 import TransclusionReferenceView from "@/features/editor/components/transclusion/transclusion-reference-view.tsx";
+import PageEmbedView from "@/features/editor/components/page-embed/page-embed-view.tsx";
 import { common, createLowlight } from "lowlight";
 import plaintext from "highlight.js/lib/languages/plaintext";
 import powershell from "highlight.js/lib/languages/powershell";
@@ -230,7 +232,7 @@ export const mainExtensions = [
  Typography,
  TrailingNode,
  GlobalDragHandle.configure({
-    customNodes: ["transclusionSource", "transclusionReference"],
+    customNodes: ["transclusionSource", "transclusionReference", "pageEmbed"],
  }),
  TextStyle,
  Color,
@@ -381,6 +383,9 @@ export const mainExtensions = [
  TransclusionReference.configure({
    view: TransclusionReferenceView,
  }),
+  PageEmbed.configure({
+    view: PageEmbedView,
+  }),
  MarkdownClipboard.configure({
    transformPastedText: true,
  }),
@@ -420,7 +425,8 @@ const TEMPLATE_EXCLUDED_SLASH_ITEMS = new Set([
  "Draw.io (diagrams.net)",
  "Excalidraw (Whiteboard)",
  "Audio",
-  "Synced block"
+  "Synced block",
+  "Embed page"
 ]);

 const TemplateSlashCommand = Command.configure({
--- a/apps/client/src/features/editor/page-editor.tsx
+++ b/apps/client/src/features/editor/page-editor.tsx
@@ -73,6 +73,9 @@ import { useEditorScroll } from "./hooks/use-editor-scroll";
 import { EditorLinkMenu } from "@/features/editor/components/link/link-menu";
 import ColumnsMenu from "@/features/editor/components/columns/columns-menu.tsx";
 import { TransclusionLookupProvider } from "@/features/editor/components/transclusion/transclusion-lookup-context";
+import { PageEmbedLookupProvider } from "@/features/editor/components/page-embed/page-embed-lookup-context";
+import { PageEmbedAncestryProvider } from "@/features/editor/components/page-embed/page-embed-ancestry-context";
+import PageEmbedPicker from "@/features/editor/components/page-embed/page-embed-picker";
 import { useTranslation } from "react-i18next";

 interface PageEditorProps {
@@ -407,6 +410,8 @@ export default function PageEditor({

  return (
    <TransclusionLookupProvider>
+      <PageEmbedLookupProvider>
+        <PageEmbedAncestryProvider hostPageId={pageId}>
      {showStatic ? (
        <EditorProvider
          editable={false}
@@ -454,6 +459,7 @@ export default function PageEditor({
            {showReadOnlyCommentPopup && (
              <CommentDialog editor={editor} pageId={pageId} readOnly />
            )}
+            {editor && editorIsEditable && <PageEmbedPicker />}
          </div>
          <div
            onClick={() => editor.commands.focus("end")}
@@ -461,6 +467,8 @@ export default function PageEditor({
          ></div>
        </div>
      )}
+        </PageEmbedAncestryProvider>
+      </PageEmbedLookupProvider>
    </TransclusionLookupProvider>
  );
 }
--- a/apps/client/src/features/page-embed/queries/page-embed-query.ts
+++ b/apps/client/src/features/page-embed/queries/page-embed-query.ts
@@ -0,0 +1,20 @@
+import { useMutation } from "@tanstack/react-query";
+import { notifications } from "@mantine/notifications";
+import { toggleTemplate } from "@/features/page-embed/services/page-embed-api";
+import type { ToggleTemplateResponse } from "@/features/page-embed/types/page-embed.types";
+
+export function useToggleTemplateMutation() {
+  return useMutation<
+    ToggleTemplateResponse,
+    Error,
+    { pageId: string; isTemplate?: boolean }
+  >({
+    mutationFn: (data) => toggleTemplate(data),
+    onError: (err: any) => {
+      notifications.show({
+        message: err?.response?.data?.message || "Failed to update template",
+        color: "red",
+      });
+    },
+  });
+}
--- a/apps/client/src/features/page-embed/services/page-embed-api.ts
+++ b/apps/client/src/features/page-embed/services/page-embed-api.ts
@@ -0,0 +1,20 @@
+import api from "@/lib/api-client";
+import type {
+  PageTemplateLookup,
+  ToggleTemplateResponse,
+} from "../types/page-embed.types";
+
+export async function lookupTemplate(params: {
+  sourcePageIds: string[];
+}): Promise<{ items: PageTemplateLookup[] }> {
+  const r = await api.post("/pages/template/lookup", params);
+  return r.data;
+}
+
+export async function toggleTemplate(params: {
+  pageId: string;
+  isTemplate?: boolean;
+}): Promise<ToggleTemplateResponse> {
+  const r = await api.post("/pages/toggle-template", params);
+  return r.data;
+}
--- a/apps/client/src/features/page-embed/types/page-embed.types.ts
+++ b/apps/client/src/features/page-embed/types/page-embed.types.ts
@@ -0,0 +1,16 @@
+export type PageTemplateLookup =
+  | {
+      sourcePageId: string;
+      slugId: string;
+      title: string | null;
+      icon: string | null;
+      content: unknown;
+      sourceUpdatedAt: string;
+    }
+  | { sourcePageId: string; status: "not_found" }
+  | { sourcePageId: string; status: "no_access" };
+
+export type ToggleTemplateResponse = {
+  pageId: string;
+  isTemplate: boolean;
+};
--- a/apps/client/src/features/page/tree/components/space-tree-node-menu.tsx
+++ b/apps/client/src/features/page/tree/components/space-tree-node-menu.tsx
@@ -12,6 +12,7 @@ import {
  IconLink,
  IconStar,
  IconStarFilled,
+  IconTemplate,
  IconTrash,
 } from "@tabler/icons-react";

@@ -30,6 +31,7 @@ import {
  useRemoveFavoriteMutation,
 } from "@/features/favorite/queries/favorite-query";

+import { useToggleTemplateMutation } from "@/features/page-embed/queries/page-embed-query";
 import { treeDataAtom } from "@/features/page/tree/atoms/tree-data-atom.ts";
 import { treeModel } from "@/features/page/tree/model/tree-model";
 import { useTreeMutation } from "@/features/page/tree/hooks/use-tree-mutation.ts";
@@ -63,6 +65,26 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
  const addFavorite = useAddFavoriteMutation();
  const removeFavorite = useRemoveFavoriteMutation();
  const isFavorited = favoriteIds.has(node.id);
+  const toggleTemplate = useToggleTemplateMutation();
+  const isTemplate = !!node.isTemplate;
+
+  const handleToggleTemplate = async () => {
+    const next = !isTemplate;
+    try {
+      await toggleTemplate.mutateAsync({ pageId: node.id, isTemplate: next });
+      // Reflect the new flag locally so the menu label updates immediately.
+      setData((prev) =>
+        treeModel.update(prev, node.id, { isTemplate: next } as any),
+      );
+      notifications.show({
+        message: next
+          ? t("Page marked as template")
+          : t("Page is no longer a template"),
+      });
+    } catch {
+      // mutation surfaces the error via notifications
+    }
+  };

  const handleCopyLink = () => {
    const pageUrl =
@@ -217,6 +239,17 @@ export function NodeMenu({ node, canEdit }: NodeMenuProps) {
                {t("Copy to space")}
              </Menu.Item>

+              <Menu.Item
+                leftSection={<IconTemplate size={16} />}
+                onClick={(e) => {
+                  e.preventDefault();
+                  e.stopPropagation();
+                  handleToggleTemplate();
+                }}
+              >
+                {isTemplate ? t("Unset as template") : t("Make template")}
+              </Menu.Item>
+
              <Menu.Divider />
              <Menu.Item
                c="red"
--- a/apps/client/src/features/page/tree/types.ts
+++ b/apps/client/src/features/page/tree/types.ts
@@ -8,5 +8,6 @@ export type SpaceTreeNode = {
  parentPageId: string;
  hasChildren: boolean;
  canEdit?: boolean;
+  isTemplate?: boolean;
  children: SpaceTreeNode[];
 };
--- a/apps/client/src/features/page/tree/utils/utils.ts
+++ b/apps/client/src/features/page/tree/utils/utils.ts
@@ -25,6 +25,7 @@ export function buildTree(pages: IPage[]): SpaceTreeNode[] {
      spaceId: page.spaceId,
      parentPageId: page.parentPageId,
      canEdit: page.canEdit ?? page.permissions?.canEdit,
+      isTemplate: page.isTemplate,
      children: [],
    };
  });
--- a/apps/client/src/features/page/types/page.types.ts
+++ b/apps/client/src/features/page/types/page.types.ts
@@ -12,6 +12,7 @@ export interface IPage {
  spaceId: string;
  workspaceId: string;
  isLocked: boolean;
+  isTemplate?: boolean;
  lastUpdatedById: string;
  createdAt: Date;
  updatedAt: Date;
--- a/apps/client/src/features/search/types/search.types.ts
+++ b/apps/client/src/features/search/types/search.types.ts
@@ -22,6 +22,7 @@ export interface SearchSuggestionParams {
  includeUsers?: boolean;
  includeGroups?: boolean;
  includePages?: boolean;
+  onlyTemplates?: boolean;
  spaceId?: string;
  limit?: number;
 }
--- a/apps/server/src/collaboration/collaboration.util.ts
+++ b/apps/server/src/collaboration/collaboration.util.ts
@@ -44,6 +44,7 @@ import {
  htmlToMarkdown,
  TransclusionSource,
  TransclusionReference,
+  PageEmbed,
 } from '@docmost/editor-ext';
 import { generateText, getSchema, JSONContent } from '@tiptap/core';
 import { generateHTML, generateJSON } from '../common/helpers/prosemirror/html';
@@ -109,6 +110,7 @@ export const tiptapExtensions = [
  Status,
  TransclusionSource,
  TransclusionReference,
+  PageEmbed,
 ] as any;

 export function jsonToHtml(tiptapJson: any) {
--- a/apps/server/src/collaboration/extensions/persistence.extension.ts
+++ b/apps/server/src/collaboration/extensions/persistence.extension.ts
@@ -371,5 +371,17 @@ export class PersistenceExtension implements Extension {
        'Failed to sync transclusion references for page',
      );
    }
+    try {
+      await this.transclusionService.syncPageTemplateReferences(
+        pageId,
+        workspaceId,
+        tiptapJson,
+      );
+    } catch (err) {
+      this.logger.error(
+        { err, pageId },
+        'Failed to sync page template references for page',
+      );
+    }
  }
 }
--- a/apps/server/src/collaboration/server/collab-app.module.ts
+++ b/apps/server/src/collaboration/server/collab-app.module.ts
@@ -13,6 +13,11 @@ import { LoggerModule } from '../../common/logger/logger.module';
 import { RedisModule } from '@nestjs-labs/nestjs-ioredis';
 import { RedisConfigService } from '../../integrations/redis/redis-config.service';
 import { CaslModule } from '../../core/casl/casl.module';
+// TransclusionModule (via CollaborationModule) registers PageTemplateController,
+// whose UserThrottlerGuard needs the throttler options from ThrottleModule. The
+// API server's AppModule imports it; the collab process must too or it fails to
+// resolve THROTTLER:MODULE_OPTIONS at boot.
+import { ThrottleModule } from '../../integrations/throttle/throttle.module';
 import { CacheModule } from '@nestjs/cache-manager';
 import KeyvRedis from '@keyv/redis';

@@ -22,6 +27,7 @@ import KeyvRedis from '@keyv/redis';
    DatabaseModule,
    EnvironmentModule,
    CaslModule,
+    ThrottleModule,
    CollaborationModule,
    QueueModule,
    HealthModule,
--- a/apps/server/src/core/page/services/page.service.ts
+++ b/apps/server/src/core/page/services/page.service.ts
@@ -319,6 +319,7 @@ export class PageService {
        'parentPageId',
        'spaceId',
        'creatorId',
+        'isTemplate',
        'deletedAt',
      ])
      .select((eb) => this.pageRepo.withHasChildren(eb))
@@ -665,6 +666,18 @@ export class PageService {
            }
          }

+          // Remap whole-page embeds (pageEmbed) the same way: if the embedded
+          // source page is also part of the copied set, point at its new copy;
+          // otherwise leave it pointing at the original (live embed of original).
+          if (node.type.name === 'pageEmbed') {
+            const sourcePageId = node.attrs.sourcePageId;
+            if (sourcePageId && pageMap.has(sourcePageId)) {
+              const mappedPage = pageMap.get(sourcePageId);
+              //@ts-ignore
+              node.attrs.sourcePageId = mappedPage.newPageId;
+            }
+          }
+
          // Update internal page links in link marks
          for (const mark of node.marks) {
            if (
@@ -757,6 +770,21 @@ export class PageService {
      );
    }

+    try {
+      await this.transclusionService.insertTemplateReferencesForPages(
+        insertablePages.map((p) => ({
+          id: p.id,
+          workspaceId: p.workspaceId,
+          content: p.content,
+        })),
+      );
+    } catch (err) {
+      this.logger.error(
+        'Failed to insert page template references for duplicated pages',
+        err,
+      );
+    }
+
    const insertedPageIds = insertablePages.map((page) => page.id);
    // `spaceId` is the single destination space for the whole copy/duplicate
    // (every inserted page above gets `spaceId: spaceId`). It lets the WS
--- a/apps/server/src/core/page/transclusion/dto/template-lookup.dto.ts
+++ b/apps/server/src/core/page/transclusion/dto/template-lookup.dto.ts
@@ -0,0 +1,12 @@
+import {
+  ArrayMaxSize,
+  IsArray,
+  IsUUID,
+} from 'class-validator';
+
+export class TemplateLookupDto {
+  @IsArray()
+  @ArrayMaxSize(50)
+  @IsUUID('all', { each: true })
+  sourcePageIds!: string[];
+}
--- a/apps/server/src/core/page/transclusion/dto/toggle-template.dto.ts
+++ b/apps/server/src/core/page/transclusion/dto/toggle-template.dto.ts
@@ -0,0 +1,11 @@
+import { IsBoolean, IsOptional, IsUUID } from 'class-validator';
+
+export class ToggleTemplateDto {
+  @IsUUID()
+  pageId!: string;
+
+  /** When omitted, the flag is toggled relative to its current value. */
+  @IsOptional()
+  @IsBoolean()
+  isTemplate?: boolean;
+}
--- a/apps/server/src/core/page/transclusion/page-template.controller.ts
+++ b/apps/server/src/core/page/transclusion/page-template.controller.ts
@@ -0,0 +1,79 @@
+import {
+  Body,
+  Controller,
+  HttpCode,
+  HttpStatus,
+  NotFoundException,
+  Post,
+  UseGuards,
+} from '@nestjs/common';
+import { Throttle } from '@nestjs/throttler';
+import { JwtAuthGuard } from '../../../common/guards/jwt-auth.guard';
+import { AuthUser } from '../../../common/decorators/auth-user.decorator';
+import { User } from '@docmost/db/types/entity.types';
+import { TransclusionService } from './transclusion.service';
+import { TemplateLookupDto } from './dto/template-lookup.dto';
+import { PageRepo } from '@docmost/db/repos/page/page.repo';
+import { PageAccessService } from '../page-access/page-access.service';
+import { ToggleTemplateDto } from './dto/toggle-template.dto';
+import { UserThrottlerGuard } from '../../../integrations/throttle/user-throttler.guard';
+import { PAGE_TEMPLATE_THROTTLER } from '../../../integrations/throttle/throttler-names';
+
+@UseGuards(JwtAuthGuard)
+@Controller('pages')
+export class PageTemplateController {
+  constructor(
+    private readonly transclusionService: TransclusionService,
+    private readonly pageRepo: PageRepo,
+    private readonly pageAccessService: PageAccessService,
+  ) {}
+
+  /**
+   * Whole-page live embed lookup for authenticated viewers. Returns current
+   * content (comment marks stripped) for accessible source pages.
+   *
+   * DoS note: the embed cycle/depth cap (PAGE_EMBED_MAX_DEPTH=5) is enforced
+   * CLIENT-side only — a scripted client could otherwise drive heavy full-doc
+   * fan-out. The server bounds the cost with this per-user throttle plus the
+   * DTO's ArrayMaxSize(50) cap; server-side recursive expansion is out of scope.
+   */
+  @UseGuards(JwtAuthGuard, UserThrottlerGuard)
+  @Throttle({ [PAGE_TEMPLATE_THROTTLER]: { limit: 30, ttl: 60000 } })
+  @HttpCode(HttpStatus.OK)
+  @Post('template/lookup')
+  async lookup(@Body() dto: TemplateLookupDto, @AuthUser() user: User) {
+    return this.transclusionService.lookupTemplate(
+      dto.sourcePageIds,
+      user.id,
+      user.workspaceId,
+    );
+  }
+
+  /**
+   * Flip `pages.is_template`. Requires Edit on the page/space (CASL is enforced
+   * inside `validateCanEdit`). The flag only affects template picker discovery;
+   * it does not restrict editing or embedding.
+   */
+  @UseGuards(JwtAuthGuard, UserThrottlerGuard)
+  @Throttle({ [PAGE_TEMPLATE_THROTTLER]: { limit: 30, ttl: 60000 } })
+  @HttpCode(HttpStatus.OK)
+  @Post('toggle-template')
+  async toggleTemplate(
+    @Body() dto: ToggleTemplateDto,
+    @AuthUser() user: User,
+  ) {
+    const page = await this.pageRepo.findById(dto.pageId);
+    if (!page || page.deletedAt) {
+      throw new NotFoundException('Page not found');
+    }
+
+    await this.pageAccessService.validateCanEdit(page, user);
+
+    const isTemplate =
+      typeof dto.isTemplate === 'boolean' ? dto.isTemplate : !page.isTemplate;
+
+    await this.pageRepo.updatePage({ isTemplate }, page.id);
+
+    return { pageId: page.id, isTemplate };
+  }
+}
--- a/apps/server/src/core/page/transclusion/spec/page-embed.util.spec.ts
+++ b/apps/server/src/core/page/transclusion/spec/page-embed.util.spec.ts
@@ -0,0 +1,102 @@
+import { collectPageEmbedsFromPmJson } from '../utils/transclusion-prosemirror.util';
+import {
+  htmlToJson,
+  jsonToHtml,
+} from '../../../../collaboration/collaboration.util';
+
+describe('collectPageEmbedsFromPmJson', () => {
+  it('returns [] for null/undefined doc', () => {
+    expect(collectPageEmbedsFromPmJson(null)).toEqual([]);
+    expect(collectPageEmbedsFromPmJson(undefined)).toEqual([]);
+  });
+
+  it('returns [] for a doc with no pageEmbed nodes', () => {
+    const doc = {
+      type: 'doc',
+      content: [{ type: 'paragraph', content: [{ type: 'text', text: 'hi' }] }],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([]);
+  });
+
+  it('extracts a top-level pageEmbed', () => {
+    const doc = {
+      type: 'doc',
+      content: [{ type: 'pageEmbed', attrs: { sourcePageId: 'p1' } }],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([{ sourcePageId: 'p1' }]);
+  });
+
+  it('skips pageEmbed nodes missing sourcePageId', () => {
+    const doc = {
+      type: 'doc',
+      content: [
+        { type: 'pageEmbed', attrs: {} },
+        { type: 'pageEmbed', attrs: { sourcePageId: '' } },
+      ],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([]);
+  });
+
+  it('dedupes identical sourcePageIds, first-seen order preserved', () => {
+    const doc = {
+      type: 'doc',
+      content: [
+        { type: 'pageEmbed', attrs: { sourcePageId: 'p1' } },
+        { type: 'pageEmbed', attrs: { sourcePageId: 'p2' } },
+        { type: 'pageEmbed', attrs: { sourcePageId: 'p1' } },
+      ],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([
+      { sourcePageId: 'p1' },
+      { sourcePageId: 'p2' },
+    ]);
+  });
+
+  it('finds pageEmbed nested in other block containers (column)', () => {
+    const doc = {
+      type: 'doc',
+      content: [
+        {
+          type: 'column',
+          content: [{ type: 'pageEmbed', attrs: { sourcePageId: 'nested' } }],
+        },
+      ],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([
+      { sourcePageId: 'nested' },
+    ]);
+  });
+
+  it('does not descend into a transclusion source', () => {
+    const doc = {
+      type: 'doc',
+      content: [
+        {
+          type: 'transclusionSource',
+          attrs: { id: 'src' },
+          content: [{ type: 'pageEmbed', attrs: { sourcePageId: 'hidden' } }],
+        },
+      ],
+    };
+    expect(collectPageEmbedsFromPmJson(doc)).toEqual([]);
+  });
+});
+
+describe('pageEmbed HTML <-> JSON round-trip (server schema)', () => {
+  it('preserves sourcePageId across jsonToHtml -> htmlToJson', () => {
+    const doc = {
+      type: 'doc',
+      content: [
+        { type: 'paragraph', content: [{ type: 'text', text: 'before' }] },
+        { type: 'pageEmbed', attrs: { sourcePageId: 'abc-123' } },
+      ],
+    };
+
+    const html = jsonToHtml(doc);
+    expect(html).toContain('data-source-page-id="abc-123"');
+
+    const back = htmlToJson(html);
+    const embeds = collectPageEmbedsFromPmJson(back);
+    expect(embeds).toEqual([{ sourcePageId: 'abc-123' }]);
+  });
+});
--- a/apps/server/src/core/page/transclusion/spec/page-template-access.spec.ts
+++ b/apps/server/src/core/page/transclusion/spec/page-template-access.spec.ts
@@ -0,0 +1,267 @@
+import { TransclusionService } from '../transclusion.service';
+
+/**
+ * Exercises the REAL security core of the whole-page template feature rather
+ * than mocking it away:
+ *  - `filterViewerAccessiblePageIds` runs for real (space-visibility query +
+ *    page-permission filter are stubbed, but the branching/AND-ing is real), so
+ *    `lookupTemplate` actually maps no_access vs content based on it.
+ *  - the workspace scoping of `page_template_references` writes is verified to
+ *    drop cross-workspace source ids before they are persisted.
+ */
+describe('TransclusionService — template access core (real filter)', () => {
+  /**
+   * Build a chainable kysely `db` stub. `selectFrom(...).select(...).where(...)`
+   * all return the same builder; `.execute()` resolves the supplied rows. The
+   * `where('spaceId','in', getUserSpaceIdsQuery(...))` sub-query argument is
+   * ignored — space visibility is decided by what `execute()` returns.
+   */
+  function makeDb(executeRows: Array<{ id: string }>) {
+    const builder: any = {};
+    builder.selectFrom = jest.fn(() => builder);
+    builder.select = jest.fn(() => builder);
+    builder.where = jest.fn(() => builder);
+    builder.execute = jest.fn(async () => executeRows);
+    return builder;
+  }
+
+  function makeService(opts: {
+    /** rows returned by the space-visibility query (workspace + space scoped) */
+    spaceVisibleRows: Array<{ id: string }>;
+    /** ids that survive page-level permission filtering */
+    permissionAccessibleIds: string[];
+    pages?: Array<{
+      id: string;
+      slugId?: string;
+      title: string | null;
+      icon: string | null;
+      content: unknown;
+      updatedAt: Date;
+    }>;
+  }) {
+    const db = makeDb(opts.spaceVisibleRows);
+
+    const spaceMemberRepo = {
+      // The real code only passes this query object into `.where(...)`; our db
+      // stub ignores it, so a sentinel is fine.
+      getUserSpaceIdsQuery: jest.fn(() => ({ __subquery: true })),
+    };
+
+    const pagePermissionRepo = {
+      filterAccessiblePageIds: jest
+        .fn()
+        .mockResolvedValue(opts.permissionAccessibleIds),
+    };
+
+    const pageRepo = {
+      findManyByIds: jest.fn().mockResolvedValue(opts.pages ?? []),
+    };
+
+    const service = new TransclusionService(
+      db as any,
+      {} as any, // pageTransclusionsRepo
+      {} as any, // pageTransclusionReferencesRepo
+      {} as any, // pageTemplateReferencesRepo
+      pageRepo as any,
+      pagePermissionRepo as any,
+      spaceMemberRepo as any,
+      {} as any, // attachmentRepo
+      {} as any, // storageService
+      {} as any, // pageAccessService
+    );
+
+    return { service, db, pageRepo, spaceMemberRepo, pagePermissionRepo };
+  }
+
+  const now = new Date('2026-06-20T00:00:00.000Z');
+
+  it('returns no_access when the viewer fails the page-permission filter (real filter runs)', async () => {
+    // Space-visible, but page-permission filter rejects it.
+    const { service, pagePermissionRepo } = makeService({
+      spaceVisibleRows: [{ id: 'p1' }],
+      permissionAccessibleIds: [],
+    });
+
+    const { items } = await service.lookupTemplate(['p1'], 'u1', 'w1');
+    expect(items).toEqual([{ sourcePageId: 'p1', status: 'no_access' }]);
+    // proves the real filter executed and consulted page permissions
+    expect(pagePermissionRepo.filterAccessiblePageIds).toHaveBeenCalledWith({
+      pageIds: ['p1'],
+      userId: 'u1',
+    });
+  });
+
+  it('returns no_access for a cross-workspace id (space-visibility query excludes it)', async () => {
+    // The workspace/space-scoped query returns nothing → permission filter is
+    // never reached and the id is not returned as accessible.
+    const { service, pagePermissionRepo } = makeService({
+      spaceVisibleRows: [],
+      permissionAccessibleIds: ['cross-ws'],
+    });
+
+    const { items } = await service.lookupTemplate(['cross-ws'], 'u1', 'w1');
+    expect(items).toEqual([{ sourcePageId: 'cross-ws', status: 'no_access' }]);
+    // short-circuited before page-permission filtering
+    expect(pagePermissionRepo.filterAccessiblePageIds).not.toHaveBeenCalled();
+  });
+
+  it('returns content with comment marks stripped for an accessible page', async () => {
+    const content = {
+      type: 'doc',
+      content: [
+        {
+          type: 'paragraph',
+          content: [
+            {
+              type: 'text',
+              text: 'hello',
+              marks: [{ type: 'comment', attrs: { commentId: 'c1' } }],
+            },
+          ],
+        },
+      ],
+    };
+
+    const { service } = makeService({
+      spaceVisibleRows: [{ id: 'p1' }],
+      permissionAccessibleIds: ['p1'],
+      pages: [
+        {
+          id: 'p1',
+          slugId: 's1',
+          title: 'Tmpl',
+          icon: '📄',
+          content,
+          updatedAt: now,
+        },
+      ],
+    });
+
+    const { items } = await service.lookupTemplate(['p1'], 'u1', 'w1');
+    const item = items[0] as any;
+    expect(item.status).toBeUndefined();
+    expect(item.title).toBe('Tmpl');
+    const json = JSON.stringify(item.content);
+    expect(json).not.toContain('comment');
+    expect(json).toContain('hello');
+  });
+
+  it('mixes accessible and inaccessible ids in one batch positionally', async () => {
+    const { service } = makeService({
+      spaceVisibleRows: [{ id: 'ok' }, { id: 'denied' }],
+      permissionAccessibleIds: ['ok'],
+      pages: [
+        {
+          id: 'ok',
+          slugId: 's',
+          title: 'A',
+          icon: null,
+          content: { type: 'doc', content: [] },
+          updatedAt: now,
+        },
+      ],
+    });
+
+    const { items } = await service.lookupTemplate(
+      ['denied', 'ok', 'cross'],
+      'u1',
+      'w1',
+    );
+    expect((items[0] as any).status).toBe('no_access'); // space-visible but no perm
+    expect((items[1] as any).status).toBeUndefined(); // accessible
+    expect((items[2] as any).status).toBe('no_access'); // not space-visible
+  });
+
+  it('honours the DTO-level ≤50 cap by deduping ids passed to the filter', async () => {
+    // The DTO enforces ArrayMaxSize(50); the service dedupes before filtering.
+    const ids = ['a', 'a', 'b'];
+    const { service, db } = makeService({
+      spaceVisibleRows: [],
+      permissionAccessibleIds: [],
+    });
+
+    await service.lookupTemplate(ids, 'u1', 'w1');
+    // db.where('id','in', <uniqueIds>) — verify the in-clause got deduped ids
+    const inCall = db.where.mock.calls.find((c: any[]) => c[0] === 'id');
+    expect(inCall?.[2]).toEqual(['a', 'b']);
+  });
+});
+
+describe('TransclusionService.syncPageTemplateReferences — workspace scoping', () => {
+  function makeService(opts: { inWorkspaceIds: string[] }) {
+    // db stub: the in-workspace existence query returns only allowed ids.
+    const builder: any = {};
+    builder.selectFrom = jest.fn(() => builder);
+    builder.select = jest.fn(() => builder);
+    builder.where = jest.fn(() => builder);
+    builder.execute = jest.fn(async () =>
+      opts.inWorkspaceIds.map((id) => ({ id })),
+    );
+
+    const insertMany = jest.fn().mockResolvedValue(undefined);
+    const deleteByReferenceAndSources = jest.fn().mockResolvedValue(undefined);
+    const pageTemplateReferencesRepo = {
+      findByReferencePageId: jest.fn().mockResolvedValue([]),
+      insertMany,
+      deleteByReferenceAndSources,
+    };
+
+    const service = new TransclusionService(
+      builder as any,
+      {} as any,
+      {} as any,
+      pageTemplateReferencesRepo as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+      {} as any,
+    );
+
+    return { service, insertMany, pageTemplateReferencesRepo };
+  }
+
+  function docWithEmbeds(sourceIds: string[]) {
+    return {
+      type: 'doc',
+      content: sourceIds.map((id) => ({
+        type: 'pageEmbed',
+        attrs: { sourcePageId: id },
+      })),
+    };
+  }
+
+  it('does NOT write a row for a cross-workspace sourcePageId, but writes the in-workspace one', async () => {
+    const { service, insertMany } = makeService({
+      // only the in-workspace id survives the existence query
+      inWorkspaceIds: ['in-ws'],
+    });
+
+    const result = await service.syncPageTemplateReferences(
+      'host',
+      'w1',
+      docWithEmbeds(['in-ws', 'cross-ws']),
+    );
+
+    expect(result.inserted).toBe(1);
+    expect(insertMany).toHaveBeenCalledTimes(1);
+    const rows = insertMany.mock.calls[0][0];
+    expect(rows).toEqual([
+      { workspaceId: 'w1', referencePageId: 'host', sourcePageId: 'in-ws' },
+    ]);
+  });
+
+  it('inserts nothing when every embed points at a cross-workspace source', async () => {
+    const { service, insertMany } = makeService({ inWorkspaceIds: [] });
+
+    const result = await service.syncPageTemplateReferences(
+      'host',
+      'w1',
+      docWithEmbeds(['cross-a', 'cross-b']),
+    );
+
+    expect(result.inserted).toBe(0);
+    expect(insertMany).not.toHaveBeenCalled();
+  });
+});
--- a/apps/server/src/core/page/transclusion/spec/page-template-lookup.spec.ts
+++ b/apps/server/src/core/page/transclusion/spec/page-template-lookup.spec.ts
@@ -0,0 +1,113 @@
+import { TransclusionService } from '../transclusion.service';
+
+/**
+ * Exercises the pure access/mapping logic of `lookupTemplate`:
+ *  - accessible + present  -> content (comments stripped) + meta
+ *  - accessible + missing  -> not_found
+ *  - inaccessible          -> no_access
+ * The access decision is taken from `filterViewerAccessiblePageIds`, which we
+ * stub; DB/repo internals are mocked.
+ */
+describe('TransclusionService.lookupTemplate (access mapping)', () => {
+  function makeService(opts: {
+    accessibleIds: string[];
+    pages: Array<{
+      id: string;
+      title: string | null;
+      icon: string | null;
+      content: unknown;
+      updatedAt: Date;
+    }>;
+  }) {
+    const pageRepo = {
+      findManyByIds: jest.fn().mockResolvedValue(opts.pages),
+    };
+
+    const service = new TransclusionService(
+      {} as any, // db
+      {} as any, // pageTransclusionsRepo
+      {} as any, // pageTransclusionReferencesRepo
+      {} as any, // pageTemplateReferencesRepo
+      pageRepo as any,
+      {} as any, // pagePermissionRepo
+      {} as any, // spaceMemberRepo
+      {} as any, // attachmentRepo
+      {} as any, // storageService
+      {} as any, // pageAccessService
+    );
+
+    jest
+      .spyOn(service, 'filterViewerAccessiblePageIds')
+      .mockResolvedValue(opts.accessibleIds);
+
+    return { service, pageRepo };
+  }
+
+  const now = new Date('2026-06-20T00:00:00.000Z');
+
+  it('returns no_access for ids the viewer cannot see', async () => {
+    const { service } = makeService({ accessibleIds: [], pages: [] });
+    const { items } = await service.lookupTemplate(['p1'], 'u1', 'w1');
+    expect(items).toEqual([{ sourcePageId: 'p1', status: 'no_access' }]);
+  });
+
+  it('returns not_found for accessible-but-missing pages', async () => {
+    const { service } = makeService({ accessibleIds: ['p1'], pages: [] });
+    const { items } = await service.lookupTemplate(['p1'], 'u1', 'w1');
+    expect(items).toEqual([{ sourcePageId: 'p1', status: 'not_found' }]);
+  });
+
+  it('returns content + meta for accessible pages and strips comment marks', async () => {
+    const content = {
+      type: 'doc',
+      content: [
+        {
+          type: 'paragraph',
+          content: [
+            {
+              type: 'text',
+              text: 'hello',
+              marks: [{ type: 'comment', attrs: { commentId: 'c1' } }],
+            },
+          ],
+        },
+      ],
+    };
+    const { service } = makeService({
+      accessibleIds: ['p1'],
+      pages: [
+        { id: 'p1', title: 'Tmpl', icon: '📄', content, updatedAt: now },
+      ],
+    });
+
+    const { items } = await service.lookupTemplate(['p1'], 'u1', 'w1');
+    expect(items).toHaveLength(1);
+    const item = items[0] as any;
+    expect(item.status).toBeUndefined();
+    expect(item.title).toBe('Tmpl');
+    expect(item.icon).toBe('📄');
+    expect(item.sourceUpdatedAt).toBe(now);
+
+    // comment mark must be gone from the returned content
+    const json = JSON.stringify(item.content);
+    expect(json).not.toContain('comment');
+    expect(json).toContain('hello');
+  });
+
+  it('maps a mixed batch positionally', async () => {
+    const { service } = makeService({
+      accessibleIds: ['ok'],
+      pages: [
+        { id: 'ok', title: 'A', icon: null, content: { type: 'doc', content: [] }, updatedAt: now },
+      ],
+    });
+    const { items } = await service.lookupTemplate(
+      ['no', 'ok', 'gone'],
+      'u1',
+      'w1',
+    );
+    expect((items[0] as any).status).toBe('no_access');
+    expect((items[1] as any).status).toBeUndefined();
+    expect((items[2] as any).status).toBe('no_access');
+  });
+});
--- a/apps/server/src/core/page/transclusion/spec/page-template.controller.spec.ts
+++ b/apps/server/src/core/page/transclusion/spec/page-template.controller.spec.ts
@@ -0,0 +1,93 @@
+import { Test } from '@nestjs/testing';
+import { ForbiddenException, NotFoundException } from '@nestjs/common';
+import { PageTemplateController } from '../page-template.controller';
+import { TransclusionService } from '../transclusion.service';
+import { PageRepo } from '@docmost/db/repos/page/page.repo';
+import { PageAccessService } from '../../page-access/page-access.service';
+import { JwtAuthGuard } from '../../../../common/guards/jwt-auth.guard';
+import { UserThrottlerGuard } from '../../../../integrations/throttle/user-throttler.guard';
+
+describe('PageTemplateController.toggleTemplate', () => {
+  let controller: PageTemplateController;
+  let pageRepo: { findById: jest.Mock; updatePage: jest.Mock };
+  let pageAccessService: { validateCanEdit: jest.Mock };
+  let transclusionService: Partial<jest.Mocked<TransclusionService>>;
+
+  const user = { id: 'u1', workspaceId: 'w1' } as any;
+  const page = {
+    id: 'p1',
+    workspaceId: 'w1',
+    deletedAt: null,
+    isTemplate: false,
+  } as any;
+
+  beforeEach(async () => {
+    pageRepo = {
+      findById: jest.fn().mockResolvedValue(page),
+      updatePage: jest.fn().mockResolvedValue(undefined),
+    };
+    pageAccessService = {
+      validateCanEdit: jest.fn().mockResolvedValue(undefined),
+    };
+    transclusionService = { lookupTemplate: jest.fn() };
+
+    const module = await Test.createTestingModule({
+      controllers: [PageTemplateController],
+      providers: [
+        { provide: TransclusionService, useValue: transclusionService },
+        { provide: PageRepo, useValue: pageRepo },
+        { provide: PageAccessService, useValue: pageAccessService },
+      ],
+    })
+      .overrideGuard(JwtAuthGuard)
+      .useValue({ canActivate: () => true })
+      .overrideGuard(UserThrottlerGuard)
+      .useValue({ canActivate: () => true })
+      .compile();
+
+    controller = module.get(PageTemplateController);
+  });
+
+  it('throws NotFound and does not touch the page when the page is missing', async () => {
+    pageRepo.findById.mockResolvedValue(null);
+    await expect(
+      controller.toggleTemplate({ pageId: 'p1' } as any, user),
+    ).rejects.toBeInstanceOf(NotFoundException);
+    expect(pageAccessService.validateCanEdit).not.toHaveBeenCalled();
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  it('enforces CASL edit: when validateCanEdit throws, the flag is NOT flipped', async () => {
+    pageAccessService.validateCanEdit.mockRejectedValue(
+      new ForbiddenException(),
+    );
+    await expect(
+      controller.toggleTemplate({ pageId: 'p1' } as any, user),
+    ).rejects.toBeInstanceOf(ForbiddenException);
+    expect(pageAccessService.validateCanEdit).toHaveBeenCalledWith(page, user);
+    expect(pageRepo.updatePage).not.toHaveBeenCalled();
+  });
+
+  it('flips is_template (toggle) when the user can edit', async () => {
+    const out = await controller.toggleTemplate(
+      { pageId: 'p1' } as any,
+      user,
+    );
+    expect(pageAccessService.validateCanEdit).toHaveBeenCalledWith(page, user);
+    // page.isTemplate was false → toggled to true
+    expect(pageRepo.updatePage).toHaveBeenCalledWith({ isTemplate: true }, 'p1');
+    expect(out).toEqual({ pageId: 'p1', isTemplate: true });
+  });
+
+  it('respects an explicit isTemplate flag instead of toggling', async () => {
+    const out = await controller.toggleTemplate(
+      { pageId: 'p1', isTemplate: false } as any,
+      user,
+    );
+    expect(pageRepo.updatePage).toHaveBeenCalledWith(
+      { isTemplate: false },
+      'p1',
+    );
+    expect(out).toEqual({ pageId: 'p1', isTemplate: false });
+  });
+});
--- a/apps/server/src/core/page/transclusion/transclusion.module.ts
+++ b/apps/server/src/core/page/transclusion/transclusion.module.ts
@@ -1,9 +1,10 @@
 import { Module } from '@nestjs/common';
 import { TransclusionController } from './transclusion.controller';
+import { PageTemplateController } from './page-template.controller';
 import { TransclusionService } from './transclusion.service';

@Module({
-  controllers: [TransclusionController],
+  controllers: [TransclusionController, PageTemplateController],
  providers: [TransclusionService],
  exports: [TransclusionService],
 })
--- a/apps/server/src/core/page/transclusion/transclusion.service.ts
+++ b/apps/server/src/core/page/transclusion/transclusion.service.ts
@@ -10,17 +10,27 @@ import { InjectKysely } from 'nestjs-kysely';
 import { KyselyDB, KyselyTransaction } from '@docmost/db/types/kysely.types';
 import { PageTransclusionsRepo } from '@docmost/db/repos/page-transclusions/page-transclusions.repo';
 import { PageTransclusionReferencesRepo } from '@docmost/db/repos/page-transclusions/page-transclusion-references.repo';
+import { PageTemplateReferencesRepo } from '@docmost/db/repos/page-template-references/page-template-references.repo';
 import { PageRepo } from '@docmost/db/repos/page/page.repo';
 import { PagePermissionRepo } from '@docmost/db/repos/page/page-permission.repo';
 import { SpaceMemberRepo } from '@docmost/db/repos/space/space-member.repo';
 import { AttachmentRepo } from '@docmost/db/repos/attachment/attachment.repo';
 import { StorageService } from '../../../integrations/storage/storage.service';
 import {
+  collectPageEmbedsFromPmJson,
  collectReferencesFromPmJson,
  collectTransclusionsFromPmJson,
 } from './utils/transclusion-prosemirror.util';
 import { rewriteAttachmentsForUnsync } from './utils/transclusion-unsync.util';
-import { TransclusionLookup } from './transclusion.types';
+import {
+  PageTemplateLookup,
+  TransclusionLookup,
+} from './transclusion.types';
+import {
+  getProsemirrorContent,
+  removeMarkTypeFromDoc,
+} from '../../../common/helpers/prosemirror/utils';
+import { jsonToNode } from '../../../collaboration/collaboration.util';
 import { Page, User } from '@docmost/db/types/entity.types';
 import { PageAccessService } from '../page-access/page-access.service';

@@ -41,6 +51,7 @@ export class TransclusionService {
    @InjectKysely() private readonly db: KyselyDB,
    private readonly pageTransclusionsRepo: PageTransclusionsRepo,
    private readonly pageTransclusionReferencesRepo: PageTransclusionReferencesRepo,
+    private readonly pageTemplateReferencesRepo: PageTemplateReferencesRepo,
    private readonly pageRepo: PageRepo,
    private readonly pagePermissionRepo: PagePermissionRepo,
    private readonly spaceMemberRepo: SpaceMemberRepo,
@@ -217,6 +228,225 @@ export class TransclusionService {
    return { inserted: rows.length };
  }

+  // ---------------------------------------------------------------------------
+  // Whole-page live embeds (pageEmbed node)
+  // ---------------------------------------------------------------------------
+
+  /**
+   * Restrict a set of candidate `pageEmbed` source ids to the pages that
+   * actually live in `workspaceId` (and are not soft-deleted). Defense in depth:
+   * `page_template_references` is NOT access-filtered, so we must never persist a
+   * reference to a cross-workspace source page. This is a single workspace-scoped
+   * existence query; it does NOT do per-viewer permission filtering (that stays
+   * the job of `lookupTemplate` at read time — see the warning below).
+   */
+  private async filterInWorkspaceSourceIds(
+    sourceIds: string[],
+    workspaceId: string,
+    trx?: KyselyTransaction,
+  ): Promise<Set<string>> {
+    if (sourceIds.length === 0) return new Set();
+    const db = trx ?? this.db;
+    const rows = await db
+      .selectFrom('pages')
+      .select('id')
+      .where('id', 'in', sourceIds)
+      .where('workspaceId', '=', workspaceId)
+      .where('deletedAt', 'is', null)
+      .execute();
+    return new Set(rows.map((r) => r.id));
+  }
+
+  /**
+   * Diff `page_template_references` for a host page against the `pageEmbed`
+   * nodes currently in its content. Mirror of `syncPageReferences` but keyed by
+   * `sourcePageId` only (whole-page, no transclusionId). Idempotent.
+   *
+   * SECURITY: `page_template_references` rows are NOT access-filtered. Inserts
+   * are restricted here to in-workspace source pages so the graph can never
+   * accumulate cross-workspace edges, but rows are still NOT per-viewer
+   * permission-filtered. EVERY consumer of these rows MUST permission-filter at
+   * read time (as `lookupTemplate` does via `filterViewerAccessiblePageIds`).
+   */
+  async syncPageTemplateReferences(
+    referencePageId: string,
+    workspaceId: string,
+    pmJson: unknown,
+    trx?: KyselyTransaction,
+  ): Promise<{ inserted: number; deleted: number }> {
+    const desired = collectPageEmbedsFromPmJson(pmJson);
+    const inWorkspace = await this.filterInWorkspaceSourceIds(
+      desired.map((d) => d.sourcePageId),
+      workspaceId,
+      trx,
+    );
+    const desiredIds = new Set(
+      desired.map((d) => d.sourcePageId).filter((id) => inWorkspace.has(id)),
+    );
+
+    const existing =
+      await this.pageTemplateReferencesRepo.findByReferencePageId(
+        referencePageId,
+        trx,
+      );
+    const existingIds = new Set(existing.map((e) => e.sourcePageId));
+
+    const toInsert = Array.from(desiredIds)
+      .filter((id) => !existingIds.has(id))
+      .map((sourcePageId) => ({
+        workspaceId,
+        referencePageId,
+        sourcePageId,
+      }));
+
+    const toDelete = existing
+      .filter((e) => !desiredIds.has(e.sourcePageId))
+      .map((e) => e.sourcePageId);
+
+    if (toInsert.length > 0) {
+      await this.pageTemplateReferencesRepo.insertMany(toInsert, trx);
+    }
+    if (toDelete.length > 0) {
+      await this.pageTemplateReferencesRepo.deleteByReferenceAndSources(
+        referencePageId,
+        toDelete,
+        trx,
+      );
+    }
+
+    return { inserted: toInsert.length, deleted: toDelete.length };
+  }
+
+  /**
+   * Bulk-insert `page_template_references` for brand-new pages (duplication,
+   * import) where there is nothing to diff against.
+   *
+   * SECURITY: like `syncPageTemplateReferences`, inserts are restricted to
+   * in-workspace source pages so the (non-access-filtered) reference graph never
+   * gains a cross-workspace edge. Read-time per-viewer permission filtering is
+   * still required by every consumer.
+   */
+  async insertTemplateReferencesForPages(
+    pages: Array<{ id: string; workspaceId: string; content: unknown }>,
+    trx?: KyselyTransaction,
+  ): Promise<{ inserted: number }> {
+    // Collect candidate source ids per workspace, then validate each workspace's
+    // set in a single existence query before building insert rows.
+    const candidatesByWorkspace = new Map<string, Set<string>>();
+    const pageEmbeds = pages.map((page) => {
+      const sourceIds = collectPageEmbedsFromPmJson(page.content).map(
+        (e) => e.sourcePageId,
+      );
+      let set = candidatesByWorkspace.get(page.workspaceId);
+      if (!set) {
+        set = new Set();
+        candidatesByWorkspace.set(page.workspaceId, set);
+      }
+      for (const id of sourceIds) set.add(id);
+      return { page, sourceIds };
+    });
+
+    const inWorkspaceByWorkspace = new Map<string, Set<string>>();
+    for (const [workspaceId, candidates] of candidatesByWorkspace) {
+      inWorkspaceByWorkspace.set(
+        workspaceId,
+        await this.filterInWorkspaceSourceIds(
+          Array.from(candidates),
+          workspaceId,
+          trx,
+        ),
+      );
+    }
+
+    const rows: Array<{
+      workspaceId: string;
+      referencePageId: string;
+      sourcePageId: string;
+    }> = [];
+    for (const { page, sourceIds } of pageEmbeds) {
+      const inWorkspace = inWorkspaceByWorkspace.get(page.workspaceId);
+      for (const sourcePageId of sourceIds) {
+        if (!inWorkspace?.has(sourcePageId)) continue;
+        rows.push({
+          workspaceId: page.workspaceId,
+          referencePageId: page.id,
+          sourcePageId,
+        });
+      }
+    }
+    if (rows.length === 0) return { inserted: 0 };
+    await this.pageTemplateReferencesRepo.insertMany(rows, trx);
+    return { inserted: rows.length };
+  }
+
+  /**
+   * Resolve whole-page content for a set of source page ids on behalf of an
+   * authenticated viewer. For each accessible page returns its current content
+   * with `comment` marks stripped (comments belong to the source). Inaccessible
+   * pages return `no_access`, missing/deleted pages return `not_found`. Does NOT
+   * require `is_template` — any accessible page can be embedded (the template
+   * flag only affects picker discovery).
+   */
+  async lookupTemplate(
+    sourcePageIds: string[],
+    viewerUserId: string,
+    workspaceId: string,
+  ): Promise<{ items: PageTemplateLookup[] }> {
+    if (sourcePageIds.length === 0) return { items: [] };
+
+    const uniqueIds = Array.from(new Set(sourcePageIds));
+    const accessibleSet = new Set(
+      await this.filterViewerAccessiblePageIds(
+        uniqueIds,
+        viewerUserId,
+        workspaceId,
+      ),
+    );
+
+    const accessibleIds = uniqueIds.filter((id) => accessibleSet.has(id));
+    const pages = await this.pageRepo.findManyByIds(accessibleIds, {
+      workspaceId,
+      includeContent: true,
+    });
+    const pageById = new Map(pages.map((p) => [p.id, p]));
+
+    const items: PageTemplateLookup[] = sourcePageIds.map((sourcePageId) => {
+      if (!accessibleSet.has(sourcePageId)) {
+        return { sourcePageId, status: 'no_access' as const };
+      }
+      const page = pageById.get(sourcePageId);
+      if (!page) {
+        return { sourcePageId, status: 'not_found' as const };
+      }
+
+      let content: unknown = null;
+      try {
+        const pmJson = getProsemirrorContent(page.content);
+        const doc = jsonToNode(pmJson);
+        content = doc ? removeMarkTypeFromDoc(doc, 'comment').toJSON() : pmJson;
+      } catch (err) {
+        this.logger.error(
+          { err, sourcePageId },
+          'Failed to prepare template content for lookup',
+        );
+        // Never return content carrying the source's comment marks. If the
+        // happy-path stripping failed, treat the page as not resolvable.
+        return { sourcePageId, status: 'not_found' as const };
+      }
+
+      return {
+        sourcePageId,
+        slugId: page.slugId,
+        title: page.title ?? null,
+        icon: page.icon ?? null,
+        content,
+        sourceUpdatedAt: page.updatedAt,
+      };
+    });
+
+    return { items };
+  }
+
  /**
   * Resolve viewer access for source page IDs supplied by an authenticated
   * caller. Restricts candidates to pages the viewer can see at the space
@@ -224,7 +454,7 @@ export class TransclusionService {
   * cannot read a sync block from a private space they don't belong to via
   * an unrestricted source page.
   */
-  private async filterViewerAccessiblePageIds(
+  async filterViewerAccessiblePageIds(
    pageIds: string[],
    viewerUserId: string,
    workspaceId: string,
--- a/apps/server/src/core/page/transclusion/transclusion.types.ts
+++ b/apps/server/src/core/page/transclusion/transclusion.types.ts
@@ -12,3 +12,15 @@ export type TransclusionNodeSnapshot = {
  transclusionId: string;
  content: unknown;
 };
+
+export type PageTemplateLookup =
+  | {
+      sourcePageId: string;
+      slugId: string;
+      title: string | null;
+      icon: string | null;
+      content: unknown;
+      sourceUpdatedAt: Date;
+    }
+  | { sourcePageId: string; status: 'not_found' }
+  | { sourcePageId: string; status: 'no_access' };
--- a/apps/server/src/core/page/transclusion/utils/transclusion-prosemirror.util.ts
+++ b/apps/server/src/core/page/transclusion/utils/transclusion-prosemirror.util.ts
@@ -2,12 +2,17 @@ import { TransclusionNodeSnapshot } from '../transclusion.types';

 const TRANSCLUSION_TYPE = 'transclusionSource';
 const REFERENCE_TYPE = 'transclusionReference';
+const PAGE_EMBED_TYPE = 'pageEmbed';

 export type TransclusionReferenceSnapshot = {
  sourcePageId: string;
  transclusionId: string;
 };

+export type PageEmbedSnapshot = {
+  sourcePageId: string;
+};
+
 /**
 * Walks a ProseMirror JSON document and returns one snapshot per top-level
 * `transclusion` node. Does not recurse into transclusions (schema disallows
@@ -93,3 +98,42 @@ export function collectReferencesFromPmJson(
  visit(doc);
  return out;
 }
+
+/**
+ * Walks a ProseMirror JSON document and returns one snapshot per unique
+ * `sourcePageId` found on `pageEmbed` nodes (whole-page live embeds). Order
+ * preserved by first-seen, duplicates deduped. `pageEmbed` is an atom so it
+ * has no relevant children; we don't descend into transclusion sources.
+ */
+export function collectPageEmbedsFromPmJson(
+  doc: unknown,
+): PageEmbedSnapshot[] {
+  if (!doc || typeof doc !== 'object') return [];
+
+  const seen = new Set<string>();
+  const out: PageEmbedSnapshot[] = [];
+
+  const visit = (node: any): void => {
+    if (!node || typeof node !== 'object') return;
+
+    if (node.type === PAGE_EMBED_TYPE) {
+      const sourcePageId = node.attrs?.sourcePageId;
+      if (typeof sourcePageId === 'string' && sourcePageId.length > 0) {
+        if (!seen.has(sourcePageId)) {
+          seen.add(sourcePageId);
+          out.push({ sourcePageId });
+        }
+      }
+      return; // atom node - no children
+    }
+
+    if (node.type === TRANSCLUSION_TYPE) return;
+
+    if (Array.isArray(node.content)) {
+      for (const child of node.content) visit(child);
+    }
+  };
+
+  visit(doc);
+  return out;
+}
--- a/apps/server/src/core/search/dto/search.dto.ts
+++ b/apps/server/src/core/search/dto/search.dto.ts
@@ -58,6 +58,10 @@ export class SearchSuggestionDTO {
  @IsBoolean()
  includePages?: boolean;

+  @IsOptional()
+  @IsBoolean()
+  onlyTemplates?: boolean;
+
  @IsOptional()
  @IsString()
  spaceId?: string;
--- a/apps/server/src/core/search/search.service.ts
+++ b/apps/server/src/core/search/search.service.ts
@@ -216,6 +216,11 @@ export class SearchService {
        .where('workspaceId', '=', workspaceId)
        .limit(limit);

+      // Template picker: restrict to pages flagged as templates.
+      if (suggestion.onlyTemplates) {
+        pageSearch = pageSearch.where('isTemplate', '=', true);
+      }
+
      // search all spaces the user has access to, prioritizing the current space
      const userSpaceIds = await this.spaceMemberRepo.getUserSpaceIds(userId);

--- a/apps/server/src/database/database.module.ts
+++ b/apps/server/src/database/database.module.ts
@@ -13,6 +13,7 @@ import { PagePermissionRepo } from './repos/page/page-permission.repo';
 import { CommentRepo } from './repos/comment/comment.repo';
 import { PageTransclusionsRepo } from './repos/page-transclusions/page-transclusions.repo';
 import { PageTransclusionReferencesRepo } from './repos/page-transclusions/page-transclusion-references.repo';
+import { PageTemplateReferencesRepo } from './repos/page-template-references/page-template-references.repo';
 import { PageHistoryRepo } from './repos/page/page-history.repo';
 import { AttachmentRepo } from './repos/attachment/attachment.repo';
 import { KyselyDB } from '@docmost/db/types/kysely.types';
@@ -86,6 +87,7 @@ import { normalizePostgresUrl } from '../common/helpers';
    PagePermissionRepo,
    PageTransclusionsRepo,
    PageTransclusionReferencesRepo,
+    PageTemplateReferencesRepo,
    PageHistoryRepo,
    CommentRepo,
    FavoriteRepo,
@@ -117,6 +119,7 @@ import { normalizePostgresUrl } from '../common/helpers';
    PagePermissionRepo,
    PageTransclusionsRepo,
    PageTransclusionReferencesRepo,
+    PageTemplateReferencesRepo,
    PageHistoryRepo,
    CommentRepo,
    FavoriteRepo,
--- a/apps/server/src/database/migrations/20260620T130000-page-is-template.ts
+++ b/apps/server/src/database/migrations/20260620T130000-page-is-template.ts
@@ -0,0 +1,20 @@
+import { type Kysely, sql } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .alterTable('pages')
+    .addColumn('is_template', 'boolean', (col) =>
+      col.notNull().defaultTo(false),
+    )
+    .execute();
+
+  // Partial index backing the template picker: only template rows are indexed.
+  await sql`CREATE INDEX pages_is_template_idx ON pages (workspace_id) WHERE is_template`.execute(
+    db,
+  );
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropIndex('pages_is_template_idx').execute();
+  await db.schema.alterTable('pages').dropColumn('is_template').execute();
+}
--- a/apps/server/src/database/migrations/20260620T131000-page-template-references.ts
+++ b/apps/server/src/database/migrations/20260620T131000-page-template-references.ts
@@ -0,0 +1,42 @@
+import { type Kysely, sql } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  await db.schema
+    .createTable('page_template_references')
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.notNull().references('workspaces.id').onDelete('cascade'),
+    )
+    .addColumn('reference_page_id', 'uuid', (col) =>
+      col.notNull().references('pages.id').onDelete('cascade'),
+    )
+    .addColumn('source_page_id', 'uuid', (col) =>
+      col.notNull().references('pages.id').onDelete('cascade'),
+    )
+    .addColumn('created_at', 'timestamptz', (col) =>
+      col.notNull().defaultTo(sql`now()`),
+    )
+    .addUniqueConstraint('page_template_references_unique', [
+      'reference_page_id',
+      'source_page_id',
+    ])
+    .execute();
+
+  await db.schema
+    .createIndex('page_template_references_source_idx')
+    .on('page_template_references')
+    .column('source_page_id')
+    .execute();
+
+  await db.schema
+    .createIndex('page_template_references_ws_idx')
+    .on('page_template_references')
+    .column('workspace_id')
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropTable('page_template_references').execute();
+}
--- a/apps/server/src/database/repos/page-template-references/page-template-references.repo.ts
+++ b/apps/server/src/database/repos/page-template-references/page-template-references.repo.ts
@@ -0,0 +1,66 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB, KyselyTransaction } from '@docmost/db/types/kysely.types';
+import { dbOrTx } from '@docmost/db/utils';
+import {
+  InsertablePageTemplateReference,
+  PageTemplateReference,
+} from '@docmost/db/types/entity.types';
+
+@Injectable()
+export class PageTemplateReferencesRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  async findByReferencePageId(
+    referencePageId: string,
+    trx?: KyselyTransaction,
+  ): Promise<PageTemplateReference[]> {
+    return dbOrTx(this.db, trx)
+      .selectFrom('pageTemplateReferences')
+      .selectAll()
+      .where('referencePageId', '=', referencePageId)
+      .execute();
+  }
+
+  async findReferencePageIdsBySource(
+    sourcePageId: string,
+    workspaceId: string,
+    trx?: KyselyTransaction,
+  ): Promise<string[]> {
+    const rows = await dbOrTx(this.db, trx)
+      .selectFrom('pageTemplateReferences')
+      .select('referencePageId')
+      .distinct()
+      .where('workspaceId', '=', workspaceId)
+      .where('sourcePageId', '=', sourcePageId)
+      .execute();
+    return rows.map((r) => r.referencePageId);
+  }
+
+  async insertMany(
+    rows: InsertablePageTemplateReference[],
+    trx?: KyselyTransaction,
+  ): Promise<void> {
+    if (rows.length === 0) return;
+    await dbOrTx(this.db, trx)
+      .insertInto('pageTemplateReferences')
+      .values(rows)
+      .onConflict((oc) =>
+        oc.columns(['referencePageId', 'sourcePageId']).doNothing(),
+      )
+      .execute();
+  }
+
+  async deleteByReferenceAndSources(
+    referencePageId: string,
+    sourcePageIds: string[],
+    trx?: KyselyTransaction,
+  ): Promise<void> {
+    if (sourcePageIds.length === 0) return;
+    await dbOrTx(this.db, trx)
+      .deleteFrom('pageTemplateReferences')
+      .where('referencePageId', '=', referencePageId)
+      .where('sourcePageId', 'in', sourcePageIds)
+      .execute();
+  }
+}
--- a/apps/server/src/database/repos/page/page.repo.ts
+++ b/apps/server/src/database/repos/page/page.repo.ts
@@ -40,6 +40,7 @@ export class PageRepo {
    'spaceId',
    'workspaceId',
    'isLocked',
+    'isTemplate',
    'createdAt',
    'updatedAt',
    'deletedAt',
@@ -112,6 +113,7 @@ export class PageRepo {
    opts?: {
      trx?: KyselyTransaction;
      workspaceId?: string;
+      includeContent?: boolean;
    },
  ): Promise<Page[]> {
    if (pageIds.length === 0) return [];
@@ -120,6 +122,7 @@ export class PageRepo {
    let query = db
      .selectFrom('pages')
      .select(this.baseFields)
+      .$if(opts?.includeContent, (qb) => qb.select('content'))
      .where('id', 'in', pageIds);

    if (opts?.workspaceId) {
--- a/apps/server/src/database/types/db.d.ts
+++ b/apps/server/src/database/types/db.d.ts
@@ -240,6 +240,14 @@ export interface PageTransclusionReferences {
  workspaceId: string;
 }

+export interface PageTemplateReferences {
+  createdAt: Generated<Timestamp>;
+  id: Generated<string>;
+  referencePageId: string;
+  sourcePageId: string;
+  workspaceId: string;
+}
+
 export interface PageTransclusions {
  content: Json;
  createdAt: Generated<Timestamp>;
@@ -281,6 +289,7 @@ export interface Pages {
  icon: string | null;
  id: Generated<string>;
  isLocked: Generated<boolean>;
+  isTemplate: Generated<boolean>;
  lastUpdatedAiChatId: string | null;
  lastUpdatedById: string | null;
  lastUpdatedSource: Generated<string>;
@@ -643,6 +652,7 @@ export interface DB {
  notifications: Notifications;
  pageAccess: PageAccess;
  pageTransclusionReferences: PageTransclusionReferences;
+  pageTemplateReferences: PageTemplateReferences;
  pageTransclusions: PageTransclusions;
  pagePermissions: PagePermissions;
  pageHistory: PageHistory;
--- a/apps/server/src/database/types/entity.types.ts
+++ b/apps/server/src/database/types/entity.types.ts
@@ -12,6 +12,7 @@ import {
  PageAccess as _PageAccess,
  PageTransclusions,
  PageTransclusionReferences,
+  PageTemplateReferences,
  PagePermissions as _PagePermissions,
  PageVerifications as _PageVerifications,
  PageVerifiers as _PageVerifiers,
@@ -188,6 +189,14 @@ export type UpdatablePageTransclusionReference = Updateable<
  Omit<PageTransclusionReferences, 'id'>
 >;

+// Page Template Reference (whole-page live embed back-references)
+export type PageTemplateReference = Selectable<PageTemplateReferences>;
+export type InsertablePageTemplateReference =
+  Insertable<PageTemplateReferences>;
+export type UpdatablePageTemplateReference = Updateable<
+  Omit<PageTemplateReferences, 'id'>
+>;
+
 // File Task
 export type FileTask = Selectable<FileTasks>;
 export type InsertableFileTask = Insertable<FileTasks>;
--- a/apps/server/src/integrations/throttle/throttle.module.ts
+++ b/apps/server/src/integrations/throttle/throttle.module.ts
@@ -7,6 +7,7 @@ import { parseRedisUrl } from '../../common/helpers';
 import {
  AUTH_THROTTLER,
  AI_CHAT_THROTTLER,
+  PAGE_TEMPLATE_THROTTLER,
  PUBLIC_SHARE_AI_THROTTLER,
 } from './throttler-names';
 import Redis from 'ioredis';
@@ -22,6 +23,11 @@ import Redis from 'ioredis';
          throttlers: [
            { name: AUTH_THROTTLER, ttl: 60_000, limit: 10 },
            { name: AI_CHAT_THROTTLER, ttl: 60_000, limit: 25 },
+            // Whole-page template lookup returns full ProseMirror docs for up
+            // to 50 ids per call and the embed depth cap is client-side only, so
+            // a scripted client could drive heavy content fan-out. 30 req/min
+            // per user is plenty for legitimate render-time batched lookups.
+            { name: PAGE_TEMPLATE_THROTTLER, ttl: 60_000, limit: 30 },
            // Anonymous public-share assistant: ~5 req/min per IP.
            { name: PUBLIC_SHARE_AI_THROTTLER, ttl: 60_000, limit: 5 },
          ],
--- a/apps/server/src/integrations/throttle/throttler-names.ts
+++ b/apps/server/src/integrations/throttle/throttler-names.ts
@@ -1,5 +1,6 @@
 export const AUTH_THROTTLER = 'auth';
 export const AI_CHAT_THROTTLER = 'ai-chat';
+export const PAGE_TEMPLATE_THROTTLER = 'page-template';
 // IP-keyed throttler for the anonymous public-share AI assistant. There is no
 // authenticated user on that route, so it is keyed by client IP (the default
 // ThrottlerGuard tracker) to bound anonymous abuse — the workspace owner pays
--- a/docs/page-templates-plan.md
+++ b/docs/page-templates-plan.md
@@ -1,184 +0,0 @@
-# Шаблоны страниц — живая вставка целой страницы в другие — дизайн
-
-> Статус: **черновик / дизайн**. Реализация ещё не начата.
-> Исходный кейс: одну страницу-«шаблон» нужно вставлять в несколько других так,
-> чтобы при правке источника вставки обновлялись автоматически.
->
-> Принятые на старте решения (выбор пользователя):
-> - **Семантика** — живая синхронная вставка (контент источника обновляется в местах вставки), НЕ статическая копия.
-> - **Сценарий** — вставка ноды в тело существующей страницы через slash-команду + пикер.
-> - **Источник** — обычная страница со спец-флагом `is_template`.
-
-## 1. Что уже есть в кодовой базе (и почему мы это расширяем)
-
-В Gitmost уже реализована **блочная транслюзия** (synced blocks) — она покрывает «вставить ОДИН блок живой ссылкой в другие страницы»:
-
- Ноды `transclusionSource` / `transclusionReference` — [packages/editor-ext/src/lib/transclusion/](../packages/editor-ext/src/lib/transclusion/).
- Таблицы `page_transclusions` (снапшот каждого source-блока на странице) и `page_transclusion_references` (кто кого ссылается) — [миграция](../apps/server/src/database/migrations/20260501T202258-page-transclusions.ts).
- Сервис [transclusion.service.ts](../apps/server/src/core/page/transclusion/transclusion.service.ts): `lookup`, `lookupWithAccessSet`, `syncPageTransclusions`, `syncPageReferences`, `unsyncReference`, `listReferences`, `insert*ForPages`.
- Контроль доступа: `filterViewerAccessiblePageIds` (членство в space + page-permissions) и публичный share-путь `ShareService.lookupTransclusionForShare` (граф доступа share, токенизация вложений, срезание комментариев).
- Клиент: read-only рендерер [transclusion-content.tsx](../apps/client/src/features/editor/components/transclusion/transclusion-content.tsx), батчинг-контекст [transclusion-lookup-context.tsx](../apps/client/src/features/editor/components/transclusion/transclusion-lookup-context.tsx), вьюха ссылки [transclusion-reference-view.tsx](../apps/client/src/features/editor/components/transclusion/transclusion-reference-view.tsx).
- Синхронизация ссылок происходит в [persistence.extension.ts](../apps/server/src/collaboration/extensions/persistence.extension.ts) (`syncTransclusion` после сохранения документа), **только для Yjs-путей** (живой коллаб). REST-обновления контента сейчас транслюзию не пересинхронизируют.
-
-**Вывод:** нужная фича — это та же транслюзия, но на уровне **целой страницы**, а не блока, плюс пометка источника флагом. ~70 % инфраструктуры переиспользуется; писать с нуля нужно только нодy `pageEmbed`, whole-page lookup, флаг `is_template` и UI-вставку.
-
-### Что НЕ переиспользуем
-
-В БД есть upstream-таблица `Templates` (Docmost), настройка `allowMemberTemplates`, тип избранного `template` и урезанный `TemplateSlashCommand`/`templateExtensions`. **Это другая, статическая механика** («создать страницу из шаблона-копии») и она не подходит под выбранный сценарий (живой синхрон + источник-страница). Не конфликтуем с ней, но и не строим на ней — ведём отдельный флаг `is_template` на странице. Урезанный `TemplateSlashCommand` к нашей фиче отношения не имеет.
-
-## 2. Модель
-
- **Шаблон** = обычная, живая, редактируемая страница с `pages.is_template = true`. Флаг меняет только то, *как* страница всплывает (пикер шаблонов, опционально — группировка/скрытие в дереве), но не запрещает её редактировать или открывать как обычную.
- **Вставка** = новая Tiptap-нода `pageEmbed` (блочная, `atom`, `isolating`) с атрибутом `sourcePageId`. Рендерится read-only: вьюха тянет **весь** текущий контент страницы-источника и показывает его. Снапшот контента в документе хоста НЕ хранится — только ссылка `sourcePageId`. За счёт этого вставка «живая».
- **Обратные ссылки** = таблица `page_template_references` (`reference_page_id`, `source_page_id`) — чтобы знать «где используется этот шаблон» (для предупреждения при удалении и инвалидации кэша). Аналог `page_transclusion_references`, но whole-page.
-
-## 3. Развилка: отдельная нода `pageEmbed` vs расширение `transclusionReference`
-
-### Вариант A (рекомендуется) — отдельная нода `pageEmbed`
-`transclusionReference` адресует конкретный блок по `transclusionId` внутри `sourcePageId`. У whole-page нет `transclusionId`. Можно было бы подставлять sentinel (`transclusionId = '__page__'`), но это засоряет инварианты уже работающей блочной транслюзии и её UNIQUE-констрейнт.
-
- **Плюсы:** проверенный блочный путь не трогаем (нулевой риск регрессии); чистое разделение; при этом переиспользуем хелперы (рендерер, батчинг, контроль доступа).
- **Минусы:** чуть больше нового кода (новая нода, вьюха, эндпоинт, таблица).
-
-### Вариант B — расширить `transclusionReference` на whole-page (`transclusionId = null`)
- **Плюсы:** максимум переиспользования (та же нода, lookup, unsync, ремап при duplicate).
- **Минусы:** NULL в UNIQUE-констрейнте Postgres ведёт себя нетривиально (NULL-ы различны); ломаются инварианты рабочей фичи; риск регрессии блочной транслюзии.
-
-**Решение:** Вариант A. Дальше дизайн исходит из `pageEmbed`.
-
-## 4. Модель данных (миграции)
-
-Соглашение по именованию: `apps/server/src/database/migrations/YYYYMMDDThhmmss-description.ts`. Только ДОБАВЛЯЕМ столбцы/таблицы. После — `pnpm --filter server migration:codegen` для регенерации `src/database/types/db.d.ts`.
-
-**Миграция 1 — флаг шаблона:**
-```sql
-ALTER TABLE pages ADD COLUMN is_template boolean NOT NULL DEFAULT false;
-- частичный индекс под пикер шаблонов
-CREATE INDEX pages_is_template_idx ON pages (workspace_id) WHERE is_template;
-```
-
-**Миграция 2 — обратные ссылки whole-page (можно отложить до фазы 2, см. §9):**
-```sql
-CREATE TABLE page_template_references (
-  id uuid PRIMARY KEY DEFAULT gen_uuid_v7(),
-  workspace_id uuid NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
-  reference_page_id uuid NOT NULL REFERENCES pages(id) ON DELETE CASCADE, -- где встроено
-  source_page_id    uuid NOT NULL REFERENCES pages(id) ON DELETE CASCADE, -- какой шаблон
-  created_at timestamptz NOT NULL DEFAULT now(),
-  UNIQUE (reference_page_id, source_page_id)
-);
-CREATE INDEX page_template_references_source_idx ON page_template_references (source_page_id);
-CREATE INDEX page_template_references_ws_idx     ON page_template_references (workspace_id);
-```
-
-## 5. Бэкенд
-
-### 5.1. Флаг `is_template`
- Тоггл: новый `POST /pages/toggle-template` (или поле в существующем `POST /pages/update`) → `pages.is_template`. Авторизация — стандартная CASL (право `Edit` на page/space, как у прочих мутаций страницы).
- `is_template` добавить в выдачу `pageRepo.findById` (колонка уже попадёт в `pages` select; убедиться, что отдаётся клиенту в `IPage`).
- Поиск: расширить search-suggestions фильтром `onlyTemplates` (для пикера показывать только `is_template = true`).
-
-### 5.2. Whole-page lookup (для авторизованных)
-Новый эндпоинт `POST /pages/template/lookup`:
-```
-Body: { sourcePageIds: string[] }   // ≤ 50, как у block-lookup
-Resp: { items: Array<
-          | { sourcePageId, title, icon, content, sourceUpdatedAt }
-          | { sourcePageId, status: 'no_access' | 'not_found' }
-        > }
-```
- Доступ: переиспользовать `filterViewerAccessiblePageIds` (членство в space + `pagePermissionRepo.filterAccessiblePageIds`). Если страница недоступна → `no_access`; удалена/нет → `not_found`.
- Контент: брать `pages.content`; **срезать `comment`-марки** (комментарии принадлежат источнику) через `removeMarkTypeFromDoc(doc, 'comment')` — как делает share-путь.
- `not_template`: можно НЕ запрещать встраивать не-шаблон (флаг — это про обнаружение в пикере, а не жёсткий констрейнт). Решение: lookup отдаёт контент любой доступной страницы; пикер же показывает только шаблоны. Это упрощает и не создаёт «битых» вставок, если со страницы потом сняли флаг.
-
-### 5.3. Синхронизация обратных ссылок
- Добавить `collectPageEmbedsFromPmJson(doc)` рядом с [transclusion-prosemirror.util.ts](../apps/server/src/core/page/transclusion/utils/transclusion-prosemirror.util.ts) — обход PM JSON, сбор `pageEmbed` нод → `{ sourcePageId }[]` (дедуп).
- Добавить `syncPageTemplateReferences(referencePageId, workspaceId, pmJson)` (diff с `page_template_references`) и дёрнуть его в `persistence.extension.syncTransclusion`.
- **Известный пробел:** REST-обновления контента (агент/AI через `updatePageContent`) не вызывают `syncTransclusion`. Для нашей фичи это терпимо: lookup работает по `sourcePageId` из самой ноды, а рассинхрон затронет только обратную таблицу (UI «где используется»). Отметить как follow-up.
-
-### 5.4. Публичный share-путь (фаза 2)
-Зеркалить `ShareService.lookupTransclusionForShare` → `POST /shares/template/lookup`:
- источник-шаблон резолвится, только если он сам попадает в граф доступа share (его шарили / есть расшаренный предок с `includeSubPages`);
- токенизация вложений источника, срезание комментариев, схлопывание `not_found → no_access` (анти-утечка).
- **UX-нюанс:** шаблоны обычно лежат вне расшаренного поддерева → по умолчанию в публичном share они дадут `no_access` (вьюха покажет плейсхолдер). Это безопасный дефолт (без случайной утечки). Альтернатива «запекать контент шаблона в хост для share-зрителя» — отдельное решение, фаза 3.
-
-### 5.5. Ремап при дублировании страниц
-В `duplicatePage` ([page.service.ts](../apps/server/src/core/page/services/page.service.ts)) уже ремапятся `mention` и `transclusionReference.sourcePageId`. Добавить ремап `pageEmbed.sourcePageId` (если источник тоже в копируемом наборе → указать на новую копию; иначе оставить как есть). Плюс `insertTemplateReferencesForPages` по аналогии с `insertReferencesForPages`.
-
-### 5.6. Регистрация ноды в серверной схеме (критично!)
-Нода `pageEmbed` должна быть зарегистрирована в **серверном** `tiptapExtensions` ([collaboration.util.ts](../apps/server/src/collaboration/collaboration.util.ts)), иначе сервер вырежет её при сохранении/коллаборации (та же ловушка, что описана в [arbitrary-html-embed-plan.md](./arbitrary-html-embed-plan.md) §2). MCP-зеркало схемы (`packages/mcp/src/lib/`) — обновлять не обязательно для MVP (MCP может трактовать ноду как opaque), отметить как follow-up.
-
-## 6. Клиент
-
-### 6.1. Нода `pageEmbed`
- Новый модуль `packages/editor-ext/src/lib/page-embed/page-embed.ts`: `Node.create({ name:'pageEmbed', group:'block', atom:true, isolating:true })`, атрибут `sourcePageId` с `parseHTML`/`renderHTML` через `data-source-page-id` (для round-trip HTML↔JSON и paste). Экспорт в `packages/editor-ext/src/index.ts`.
- Регистрация в клиентских `mainExtensions` ([extensions.ts](../apps/client/src/features/editor/extensions/extensions.ts)) и серверной схеме (§5.6).
-
-### 6.2. NodeView `page-embed-view.tsx`
- Тянет whole-page контент через `useTemplateLookup` (расширить/обобщить батчинг-паттерн `transclusion-lookup-context.tsx`, или TanStack Query с ключом `sourcePageId`).
- Тело рендерит read-only вложенным редактором по образцу [transclusion-content.tsx](../apps/client/src/features/editor/components/transclusion/transclusion-content.tsx) (изоляция событий, `editable=false`, `UniqueID` с `updateDocument:false`).
- Шапка: иконка+заголовок шаблона со ссылкой на источник, кнопка «обновить», меню «отвязать → превратить в статическую копию» (новый `unsyncPageEmbed`, запекает текущий контент в документ хоста — по образцу `unsyncReference`).
- **Защита от циклов** (см. §7.1).
-
-### 6.3. Slash-команда + пикер
- Slash-пункт `/template` (или `/embed page`) открывает пикер страниц — переиспользовать [mention-list.tsx](../apps/client/src/features/editor/components/mention/mention-list.tsx) + search-query с фильтром `onlyTemplates` → вставляет `pageEmbed` с выбранным `sourcePageId`.
-
-### 6.4. Пометить страницу как шаблон
- Тоггл «Сделать шаблоном / Снять» в меню узла дерева ([space-tree-node-menu.tsx](../apps/client/src/features/page/tree/components/space-tree-node-menu.tsx)) и/или в «...» меню заголовка страницы → мутация на `POST /pages/toggle-template`.
- (Опционально, фаза 2) Галерея/раздел «Шаблоны».
-
-## 7. Краевые случаи (главное)
-
-### 7.1. Циклы / бесконечная рекурсия (самое важное)
-A встраивает B, B встраивает A → бесконечная вложенность на клиенте. Сервер из lookup отдаёт «сырой» контент одного уровня и зациклиться не может — **гард обязателен на клиенте**:
- React-контекст с цепочкой `sourcePageId` предков; если текущий `sourcePageId` уже в цепочке → рендерить плейсхолдер «циклическая вставка», не рекурсировать.
- Жёсткий лимит глубины вложенности (например, 5).
- При выборе в пикере запрещать вставку самой текущей страницы (self-embed). Полное обнаружение циклов на вставке (обход графа) — избыточно, опираемся на рендер-гард.
-
-### 7.2. Удаление шаблона
-Удаление страницы-шаблона — soft-delete (корзина) → вставки дают `not_found`/`no_access`, вьюха показывает «шаблон в корзине/не найден». Таблица `page_template_references` позволяет предупредить «используется в N страницах» перед удалением. При восстановлении вставки снова резолвятся.
-
-### 7.3. Доступ
-Зритель хоста может не иметь доступа к странице-источнику (другой space/ограничение) → lookup вернёт `no_access`, вьюха — плейсхолдер. Это корректно (без утечки).
-
-### 7.4. Комментарии
-Срезать `comment`-марки из встроенного контента (`removeMarkTypeFromDoc`) — комментарии относятся к источнику.
-
-### 7.5. Вложения
-Встроенный контент ссылается на вложения источника. Для авторизованных доступ обычный (lookup уже проверил доступ к источнику). Для публичных share — токенизация по образцу share-пути (фаза 2).
-
-### 7.6. Вложенные транслюзии внутри шаблона
-Шаблон может содержать `transclusionSource`/`transclusionReference`/`pageEmbed`. При whole-page рендере они отрисуются своими вьюхами (доп. вложенные lookup-и) — работает, но учитывать в гарде глубины (§7.1).
-
-### 7.7. История версий хоста
-В истории хоста хранится только нода-ссылка (мелкая), не снапшот. Значит старые версии хоста покажут *текущий* контент шаблона (живой), без point-in-time точности. Снапшот-режим — вне scope, отметить.
-
-### 7.8. Экспорт (Markdown/HTML) и RAG/поиск
-`jsonToHtml`/`jsonToMarkdown`/`jsonToText` на сервере не развернут `pageEmbed` (в документе только ссылка) → экспорт и `textContent` хоста не содержат текста шаблона; полнотекстовый/RAG-поиск не найдёт хост по тексту шаблона. Для MVP — плейсхолдер/ссылка; серверное разворачивание вставок при экспорте/индексации — фаза 3.
-
-## 8. Реестр переиспользования
-
-| Что | Файл | Как используем |
-| --- | --- | --- |
-| Read-only рендерер | `transclusion-content.tsx` | тело `pageEmbed` |
-| Батчинг lookup | `transclusion-lookup-context.tsx` | `useTemplateLookup` |
-| Контроль доступа | `transclusion.service.ts::filterViewerAccessiblePageIds` / `lookupWithAccessSet` | whole-page lookup |
-| Share-путь | `share.service.ts::lookupTransclusionForShare` | `lookupTemplateForShare` (фаза 2) |
-| Sync ссылок | `persistence.extension.ts::syncTransclusion` + `collectReferencesFromPmJson` | `+ collectPageEmbedsFromPmJson` / `syncPageTemplateReferences` |
-| Unsync→копия | `transclusion.service.ts::unsyncReference` | `unsyncPageEmbed` |
-| Пикер страниц | `mention-list.tsx` + search-query | пикер шаблонов (`onlyTemplates`) |
-| Ремап при копировании | `page.service.ts::duplicatePage` | `+ ремап pageEmbed.sourcePageId` |
-| Меню страницы | `space-tree-node-menu.tsx` | тоггл «Сделать шаблоном» |
-| Серверная схема | `collaboration.util.ts::tiptapExtensions` | регистрация `pageEmbed` (критично) |
-
-## 9. Этапность
-
- **MVP:** флаг `is_template` + тоггл-UI; нода `pageEmbed` + вьюха (живой read-only fetch с гардом циклов); `/template` slash + пикер; auth-эндпоинт lookup; синхронизация ссылок; ремап при duplicate. Без share (на публичных страницах — плейсхолдер), без разворачивания при экспорте. Таблица `page_template_references` — желательна, но можно начать с резолва по in-doc нодам.
- **Фаза 2:** публичный share-lookup; «отвязать → статическая копия»; «используется в N страницах» + предупреждение при удалении; галерея шаблонов.
- **Фаза 3:** разворачивание вставок на сервере для экспорта/RAG/textContent; режим point-in-time снапшота; обновление MCP-зеркала схемы; sync ссылок на REST-пути.
-
-## 10. Открытые вопросы
-
-1. Прятать ли страницы-шаблоны из обычного дерева space или показывать с бейджем? (предлагаю: показывать с бейджем, отдельную «галерею» — фаза 2).
-2. Ограничивать ли источник только `is_template`-страницами на бэке, или разрешать встраивать любую доступную (флаг — только для пикера)? (предлагаю второе — меньше «битых» вставок).
-3. Нужен ли whole-page embed на публичных share сразу в MVP или плейсхолдер достаточен на старте? (предлагаю плейсхолдер → фаза 2).
--- a/packages/editor-ext/src/index.ts
+++ b/packages/editor-ext/src/index.ts
@@ -22,6 +22,7 @@ export * from "./lib/search-and-replace";
 export * from "./lib/embed-provider";
 export * from "./lib/subpages";
 export * from "./lib/transclusion";
+export * from "./lib/page-embed";
 export * from "./lib/highlight";
 export * from "./lib/indent";
 export * from "./lib/heading/heading";
--- a/packages/editor-ext/src/lib/page-embed/index.ts
+++ b/packages/editor-ext/src/lib/page-embed/index.ts
@@ -0,0 +1 @@
+export * from "./page-embed";
--- a/packages/editor-ext/src/lib/page-embed/page-embed.ts
+++ b/packages/editor-ext/src/lib/page-embed/page-embed.ts
@@ -0,0 +1,88 @@
+import { mergeAttributes, Node } from "@tiptap/core";
+import { ReactNodeViewRenderer } from "@tiptap/react";
+
+export interface PageEmbedOptions {
+  HTMLAttributes: Record<string, any>;
+  view: any;
+}
+
+export interface PageEmbedAttributes {
+  sourcePageId?: string | null;
+}
+
+declare module "@tiptap/core" {
+  interface Commands<ReturnType> {
+    pageEmbed: {
+      insertPageEmbed: (attributes: PageEmbedAttributes) => ReturnType;
+    };
+  }
+}
+
+/**
+ * Whole-page live embed. Holds only a `sourcePageId` reference; the node view
+ * fetches the source page's current content at render time, so the embed stays
+ * live (no snapshot is stored in the host document). Separate from
+ * `transclusionReference` (which addresses a single block by `transclusionId`).
+ */
+export const PageEmbed = Node.create<PageEmbedOptions>({
+  name: "pageEmbed",
+
+  addOptions() {
+    return {
+      HTMLAttributes: {},
+      view: null,
+    };
+  },
+
+  group: "block",
+  atom: true,
+  isolating: true,
+  selectable: true,
+  draggable: true,
+
+  addAttributes() {
+    return {
+      sourcePageId: {
+        default: null,
+        parseHTML: (el) => el.getAttribute("data-source-page-id"),
+        renderHTML: (attrs) =>
+          attrs.sourcePageId
+            ? { "data-source-page-id": attrs.sourcePageId }
+            : {},
+      },
+    };
+  },
+
+  parseHTML() {
+    return [{ tag: `div[data-type="${this.name}"]` }];
+  },
+
+  renderHTML({ HTMLAttributes }) {
+    return [
+      "div",
+      mergeAttributes(
+        { "data-type": this.name },
+        this.options.HTMLAttributes,
+        HTMLAttributes,
+      ),
+    ];
+  },
+
+  addCommands() {
+    return {
+      insertPageEmbed:
+        (attributes) =>
+        ({ commands }) =>
+          commands.insertContent({
+            type: this.name,
+            attrs: attributes,
+          }),
+    };
+  },
+
+  addNodeView() {
+    if (!this.options.view) return null;
+    this.editor.isInitialized = true;
+    return ReactNodeViewRenderer(this.options.view);
+  },
+});