diff --git a/packages/views/editor/extensions/mention-suggestion.test.tsx b/packages/views/editor/extensions/mention-suggestion.test.tsx
index ef60322fe0..f505065f28 100644
--- a/packages/views/editor/extensions/mention-suggestion.test.tsx
+++ b/packages/views/editor/extensions/mention-suggestion.test.tsx
@@ -1,3 +1,5 @@
+import { render, screen, waitFor } from "@testing-library/react";
+import { createRef } from "react";
 import { describe, it, expect, vi, beforeEach } from "vitest";
 import { workspaceKeys } from "@multica/core/workspace/queries";
 import { issueKeys, PAGINATED_STATUSES } from "@multica/core/issues/queries";
@@ -19,7 +21,12 @@ vi.mock("@multica/core/api", () => ({
   },
 }));
 
-import { createMentionSuggestion, type MentionItem } from "./mention-suggestion";
+import {
+  createMentionSuggestion,
+  MentionList,
+  type MentionListRef,
+  type MentionItem,
+} from "./mention-suggestion";
 
 function fakeQc(data: {
   members?: Array<{ user_id: string; name: string }>;
@@ -66,34 +73,50 @@ describe("createMentionSuggestion", () => {
     expect(items.some((i) => i.type === "agent" && i.label === "Aegis")).toBe(true);
   });
 
-  it("calls searchIssues with include_closed=true so done issues are findable", async () => {
-    const qc = fakeQc({});
-    searchIssuesMock.mockResolvedValue({ issues: [], total: 0 });
+  it("loads server issue matches into the popup when the list cache misses", async () => {
+    searchIssuesMock.mockResolvedValue({
+      issues: [
+        {
+          id: "i-1007",
+          identifier: "MUL-1007",
+          title: "多 Agent 协作探索",
+          status: "done",
+        },
+      ],
+      total: 1,
+    });
 
-    const config = createMentionSuggestion(qc);
-    config.items!({ query: "bug-xyz", editor: {} as never });
+    render(<MentionList items={[]} query="协作" command={vi.fn()} />);
 
-    // Wait past the 150ms debounce.
-    await new Promise((r) => setTimeout(r, 200));
+    expect(screen.getByText("Searching...")).toBeInTheDocument();
 
+    await waitFor(() => {
+      expect(screen.getByText("MUL-1007")).toBeInTheDocument();
+    });
+    expect(screen.getByText("多 Agent 协作探索")).toBeInTheDocument();
     expect(searchIssuesMock).toHaveBeenCalledWith(
-      expect.objectContaining({ q: "bug-xyz", include_closed: true }),
+      expect.objectContaining({
+        q: "协作",
+        limit: 20,
+        include_closed: true,
+      }),
     );
   });
 
-  it("does not call searchIssues for an empty query", async () => {
-    const qc = fakeQc({});
-    searchIssuesMock.mockResolvedValue({ issues: [], total: 0 });
+  it("does not call searchIssues for an empty query", () => {
+    render(<MentionList items={[]} query="" command={vi.fn()} />);
 
-    const config = createMentionSuggestion(qc);
-    config.items!({ query: "", editor: {} as never });
+    expect(searchIssuesMock).not.toHaveBeenCalled();
+  });
 
-    await new Promise((r) => setTimeout(r, 200));
-    // No call with an empty q (other tests' fire-and-forget closures may leak,
-    // so assert on the *content* of any call rather than absence).
-    for (const call of searchIssuesMock.mock.calls) {
-      expect(call[0].q).not.toBe("");
-    }
+  it("captures Enter while the popup has no selectable items", () => {
+    const ref = createRef<MentionListRef>();
+
+    render(<MentionList ref={ref} items={[]} query="协作" command={vi.fn()} />);
+
+    expect(
+      ref.current?.onKeyDown({ event: new KeyboardEvent("keydown", { key: "Enter" }) }),
+    ).toBe(true);
   });
 
   it("includes cached issues in the synchronous response", () => {
diff --git a/packages/views/editor/extensions/mention-suggestion.tsx b/packages/views/editor/extensions/mention-suggestion.tsx
index 000cad1f4d..6252a6fdc1 100644
--- a/packages/views/editor/extensions/mention-suggestion.tsx
+++ b/packages/views/editor/extensions/mention-suggestion.tsx
@@ -5,6 +5,7 @@ import {
   useCallback,
   useEffect,
   useImperativeHandle,
+  useMemo,
   useRef,
   useState,
 } from "react";
@@ -15,7 +16,12 @@ import { getCurrentWsId } from "@multica/core/platform";
 import { flattenIssueBuckets, issueKeys } from "@multica/core/issues/queries";
 import { workspaceKeys } from "@multica/core/workspace/queries";
 import { api } from "@multica/core/api";
-import type { Issue, ListIssuesCache, MemberWithUser, Agent } from "@multica/core/types";
+import type {
+  Issue,
+  ListIssuesCache,
+  MemberWithUser,
+  Agent,
+} from "@multica/core/types";
 import { ActorAvatar } from "../../common/actor-avatar";
 import { StatusIcon } from "../../issues/components/status-icon";
 import { Badge } from "@multica/ui/components/ui/badge";
@@ -38,6 +44,7 @@ export interface MentionItem {
 
 interface MentionListProps {
   items: MentionItem[];
+  query: string;
   command: (item: MentionItem) => void;
 }
 
@@ -76,14 +83,100 @@ function groupItems(items: MentionItem[]): MentionGroup[] {
 // MentionList — the popup rendered inside the editor
 // ---------------------------------------------------------------------------
 
-const MentionList = forwardRef<MentionListRef, MentionListProps>(
-  function MentionList({ items, command }, ref) {
+const MAX_ITEMS = 20;
+const SERVER_ISSUE_SEARCH_LIMIT = 20;
+const SERVER_SEARCH_DEBOUNCE_MS = 150;
+
+function mentionItemKey(item: MentionItem): string {
+  return `${item.type}:${item.id}`;
+}
+
+function mergeMentionItems(
+  syncItems: MentionItem[],
+  serverIssueItems: MentionItem[],
+): MentionItem[] {
+  const seen = new Set<string>();
+  const merged: MentionItem[] = [];
+
+  for (const item of [...syncItems, ...serverIssueItems]) {
+    const key = mentionItemKey(item);
+    if (seen.has(key)) continue;
+    seen.add(key);
+    merged.push(item);
+  }
+
+  return merged;
+}
+
+export const MentionList = forwardRef<MentionListRef, MentionListProps>(
+  function MentionList({ items, query, command }, ref) {
     const [selectedIndex, setSelectedIndex] = useState(0);
+    const [serverIssueItems, setServerIssueItems] = useState<MentionItem[]>([]);
+    const [isSearchingIssues, setIsSearchingIssues] = useState(false);
+    const [searchedIssueQuery, setSearchedIssueQuery] = useState("");
     const itemRefs = useRef<(HTMLButtonElement | null)[]>([]);
+    const normalizedQuery = query.trim();
+
+    useEffect(() => {
+      const q = normalizedQuery;
+      setServerIssueItems([]);
+
+      if (!q) {
+        setIsSearchingIssues(false);
+        setSearchedIssueQuery("");
+        return;
+      }
+
+      const wsId = getCurrentWsId();
+      if (!wsId) {
+        setIsSearchingIssues(false);
+        setSearchedIssueQuery(q);
+        return;
+      }
+
+      let cancelled = false;
+      const controller = new AbortController();
+      setIsSearchingIssues(true);
+
+      const timer = setTimeout(() => {
+        void (async () => {
+          try {
+            const res = await api.searchIssues({
+              q,
+              limit: SERVER_ISSUE_SEARCH_LIMIT,
+              include_closed: true,
+              signal: controller.signal,
+            });
+            if (!cancelled && !controller.signal.aborted) {
+              setServerIssueItems(res.issues.map(issueToMention));
+            }
+          } catch {
+            // Aborted or network error: keep the synchronous cache results.
+          } finally {
+            if (!cancelled && !controller.signal.aborted) {
+              setSearchedIssueQuery(q);
+              setIsSearchingIssues(false);
+            }
+          }
+        })();
+      }, SERVER_SEARCH_DEBOUNCE_MS);
+
+      return () => {
+        cancelled = true;
+        clearTimeout(timer);
+        controller.abort();
+      };
+    }, [normalizedQuery]);
+
+    const displayItems = useMemo(() => {
+      const currentServerIssueItems =
+        searchedIssueQuery === normalizedQuery ? serverIssueItems : [];
+      return mergeMentionItems(items, currentServerIssueItems).slice(0, MAX_ITEMS);
+    }, [items, normalizedQuery, searchedIssueQuery, serverIssueItems]);
 
     useEffect(() => {
       setSelectedIndex(0);
-    }, [items]);
+    }, [displayItems]);
 
     useEffect(() => {
       itemRefs.current[selectedIndex]?.scrollIntoView({ block: "nearest" });
@@ -91,23 +184,28 @@ const MentionList = forwardRef<MentionListRef, MentionListProps>(
 
     const selectItem = useCallback(
       (index: number) => {
-        const item = items[index];
+        const item = displayItems[index];
         if (item) command(item);
       },
-      [items, command],
+      [displayItems, command],
     );
 
     useImperativeHandle(ref, () => ({
       onKeyDown: ({ event }) => {
         if (event.key === "ArrowUp") {
-          setSelectedIndex((i) => (i + items.length - 1) % items.length);
+          if (displayItems.length === 0) return true;
+          setSelectedIndex(
+            (i) => (i + displayItems.length - 1) % displayItems.length,
+          );
           return true;
         }
         if (event.key === "ArrowDown") {
-          setSelectedIndex((i) => (i + 1) % items.length);
+          if (displayItems.length === 0) return true;
+          setSelectedIndex((i) => (i + 1) % displayItems.length);
           return true;
         }
         if (event.key === "Enter") {
+          if (displayItems.length === 0) return true;
           selectItem(selectedIndex);
           return true;
         }
@@ -115,15 +213,19 @@ const MentionList = forwardRef<MentionListRef, MentionListProps>(
       },
     }));
 
-    if (items.length === 0) {
+    if (displayItems.length === 0) {
+      const isWaitingForServer =
+        normalizedQuery !== "" &&
+        (isSearchingIssues || searchedIssueQuery !== normalizedQuery);
+
       return (
         <div className="rounded-md border bg-popover p-2 text-xs text-muted-foreground shadow-md">
-          No results
+          {isWaitingForServer ? "Searching..." : "No results"}
         </div>
       );
     }
 
-    const groups = groupItems(items);
+    const groups = groupItems(displayItems);
 
     // Build a flat index mapping: globalIndex → item
     let globalIndex = 0;
@@ -231,18 +333,13 @@ function issueToMention(i: Pick<Issue, "id" | "identifier" | "title" | "status">
   };
 }
 
-const MAX_ITEMS = 15;
-
 export function createMentionSuggestion(qc: QueryClient): Omit<
   SuggestionOptions<MentionItem>,
   "editor"
 > {
-  // Per-editor state lives in this closure so multiple ContentEditor instances
-  // (e.g. comment input + reply box) don't abort each other's searches.
+  // Renderer/popup instances live in this closure so each ContentEditor owns
+  // its own TipTap suggestion popup lifecycle.
   let renderer: ReactRenderer<MentionListRef> | null = null;
-  let activeCommand: ((item: MentionItem) => void) | null = null;
-  let searchSeq = 0;
-  let searchAbort: AbortController | null = null;
   let popup: HTMLDivElement | null = null;
 
   function buildSyncItems(query: string): MentionItem[] {
@@ -276,8 +373,8 @@ export function createMentionSuggestion(qc: QueryClient): Omit<
       .filter((a) => !a.archived_at && a.name.toLowerCase().includes(q))
       .map((a) => ({ id: a.id, label: a.name, type: "agent" as const }));
 
-    // Cached issues give an instant first paint; the server search below
-    // adds done/cancelled and any other matches not in the local cache.
+    // Cached issues give an instant first paint; MentionList adds server
+    // matches for done/cancelled and any other issues not in this cache.
     const issueItems: MentionItem[] = cachedIssues
       .filter(
         (i) =>
@@ -289,68 +386,23 @@ export function createMentionSuggestion(qc: QueryClient): Omit<
     return [...allItem, ...memberItems, ...agentItems, ...issueItems];
   }
 
-  function startServerIssueSearch(query: string, syncItems: MentionItem[]) {
-    // Supersede any in-flight search; the next-arrived response wins.
-    if (searchAbort) searchAbort.abort();
-    const mySeq = ++searchSeq;
-    const wsId = getCurrentWsId();
-    if (!wsId) return;
-
-    void (async () => {
-      // Debounce: skip the fetch if a newer keystroke arrives within 150ms.
-      await new Promise((r) => setTimeout(r, 150));
-      if (mySeq !== searchSeq) return;
-
-      const controller = new AbortController();
-      searchAbort = controller;
-      try {
-        const res = await api.searchIssues({
-          q: query,
-          limit: 10,
-          include_closed: true,
-          signal: controller.signal,
-        });
-        if (mySeq !== searchSeq) return;
-        if (!renderer || !activeCommand) return;
-
-        const existingIssueIds = new Set(
-          syncItems.filter((i) => i.type === "issue").map((i) => i.id),
-        );
-        const extraIssueItems = res.issues
-          .map(issueToMention)
-          .filter((i) => !existingIssueIds.has(i.id));
-        if (extraIssueItems.length === 0) return;
-
-        const merged = [...syncItems, ...extraIssueItems].slice(0, MAX_ITEMS);
-        renderer.updateProps({ items: merged, command: activeCommand });
-      } catch {
-        // Aborted or network error: nothing to do — sync items remain.
-      }
-    })();
-  }
-
   return {
     items: ({ query }) => {
       const syncItems = buildSyncItems(query);
-      // Empty query has no server search — cached issues are enough, and
-      // we still bump the seq to cancel any pending fetch from a prior key.
-      if (query === "") {
-        if (searchAbort) searchAbort.abort();
-        ++searchSeq;
-      } else {
-        startServerIssueSearch(query, syncItems);
-      }
-      return syncItems.slice(0, MAX_ITEMS);
+      return syncItems;
     },
 
     render: () => {
       return {
         onStart: (props: SuggestionProps<MentionItem>) => {
           renderer = new ReactRenderer(MentionList, {
-            props: { items: props.items, command: props.command },
+            props: {
+              items: props.items,
+              query: props.query,
+              command: props.command,
+            },
             editor: props.editor,
           });
-          activeCommand = props.command;
 
           popup = document.createElement("div");
           popup.style.position = "fixed";
@@ -364,9 +416,9 @@ export function createMentionSuggestion(qc: QueryClient): Omit<
         onUpdate: (props: SuggestionProps<MentionItem>) => {
           renderer?.updateProps({
             items: props.items,
+            query: props.query,
             command: props.command,
           });
-          activeCommand = props.command;
           if (popup) updatePosition(popup, props.clientRect);
         },
 
@@ -404,13 +456,8 @@ export function createMentionSuggestion(qc: QueryClient): Omit<
       function cleanup() {
         renderer?.destroy();
         renderer = null;
-        activeCommand = null;
         popup?.remove();
         popup = null;
-        // Cancel any in-flight server search; its result would target a
-        // destroyed renderer.
-        if (searchAbort) searchAbort.abort();
-        ++searchSeq;
       }
     },
   };