diff --git a/client/mentions.test.ts b/client/mentions.test.ts
new file mode 100644
index 0000000..da7f567
--- /dev/null
+++ b/client/mentions.test.ts
@@ -0,0 +1,52 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { TASK_KEY, matchTasks } from "./mentions.ts";
+import type { Task, TaskStatus } from "./types.ts";
+
+const task = (key: string, title: string, status: TaskStatus, updated: number) =>
+  ({
+    id: `id-${key}`,
+    key,
+    title,
+    outcome: "",
+    status,
+    discussion_channel_id: "c1",
+    created_by: "u1",
+    created_at: 0,
+    updated_at: updated,
+    position: 0,
+  }) as Task;
+
+const tasks = [
+  task("PW-1", "Ship the relay", "done", 300),
+  task("PW-42", "Allow mentioning tasks", "planned", 100),
+  task("ACME-7", "Cache the pricing endpoint", "running", 200),
+];
+
+test("open work is offered before finished work, newest first", () => {
+  assert.deepEqual(
+    matchTasks(tasks, "").map((found) => found.key),
+    ["ACME-7", "PW-42", "PW-1"],
+  );
+});
+
+test("a key or a word from the title finds the task", () => {
+  assert.deepEqual(
+    matchTasks(tasks, "pw-4").map((found) => found.key),
+    ["PW-42"],
+  );
+  assert.deepEqual(
+    matchTasks(tasks, "pricing").map((found) => found.key),
+    ["ACME-7"],
+  );
+  assert.deepEqual(matchTasks(tasks, "nothing here"), []);
+});
+
+test("a key is recognised in prose but not inside a longer token", () => {
+  const find = (text: string) => text.match(new RegExp(TASK_KEY.source))?.[1];
+  assert.equal(find("landed in PW-42, see above"), "PW-42");
+  assert.equal(find("ACME-7"), "ACME-7");
+  assert.equal(find("v2-1024-beta"), undefined);
+  assert.equal(find("plain words"), undefined);
+});
diff --git a/client/mentions.ts b/client/mentions.ts
new file mode 100644
index 0000000..0806abd
--- /dev/null
+++ b/client/mentions.ts
@@ -0,0 +1,29 @@
+// Mentioning a task is just writing its key. `PW-42` in a message is the same
+// reference everywhere — typed by a person, printed by an agent, or copied out
+// of the CLI — so the composer only has to help find the key, and the renderer
+// only has to recognise the keys that name a real task.
+
+import type { Task } from "./types";
+
+/// The shape of a key: the workspace prefix is configurable, so this matches
+/// `ACME-7` as readily as `PW-42` and the caller decides which keys are real.
+export const TASK_KEY = /(?<![\w-])([A-Za-z][A-Za-z0-9]*-\d+)(?![\w-])/;
+
+const finished = (task: Task) => task.status === "done" || task.status === "canceled";
+
+/// Tasks worth offering for what has been typed after `#`, open work first and
+/// most recently touched before the rest.
+export function matchTasks(tasks: Task[], query: string, limit = 6): Task[] {
+  const needle = query.trim().toLowerCase();
+  return tasks
+    .filter(
+      (task) =>
+        task.key.toLowerCase().includes(needle) ||
+        task.title.toLowerCase().includes(needle),
+    )
+    .sort(
+      (a, b) =>
+        Number(finished(a)) - Number(finished(b)) || b.updated_at - a.updated_at,
+    )
+    .slice(0, limit);
+}
diff --git a/desktop/src/components/Chat.tsx b/desktop/src/components/Chat.tsx
index b60c942..000313c 100644
--- a/desktop/src/components/Chat.tsx
+++ b/desktop/src/components/Chat.tsx
@@ -7,7 +7,8 @@ import {
   useState,
 } from "react";
 import { store, useApi, useAppSelector } from "../lib/store";
-import { bytes, dayLabel, duration, timeOfDay } from "../lib/format";
+import { bytes, dayLabel, duration, statusLabel, timeOfDay } from "../lib/format";
+import { matchTasks } from "@client/mentions";
 import { useVirtualWindow } from "../lib/virtual";
 import { useBottomAnchor } from "../lib/scroll";
 import { useFileUrl } from "../lib/file";
@@ -27,6 +28,7 @@ import {
   RunIcon,
   SendIcon,
   Spinner,
+  TasksIcon,
   ThreadIcon,
 } from "./icons";
 import { Menu, type MenuItem } from "./ui";
@@ -257,7 +259,8 @@ export function Timeline({
       <div className="timeline-inner" ref={contentRef}>
         {messages.length === 0 && (
           <div className="empty">
-            Nothing here yet. Say something, or bring an agent in with @.
+            Nothing here yet. Say something, bring an agent in with @, or point
+            at a task with #.
           </div>
         )}
         {window_.padTop > 0 && <div style={{ height: window_.padTop }} />}
@@ -919,14 +922,16 @@ function ComposerBox({
   onCancelReply,
 }: ComposerProps & { draftKey: string }) {
   const api = useApi();
-  const { members, me } = useAppSelector((data) => ({
+  const { members, me, tasks } = useAppSelector((data) => ({
     members: data.members,
     me: data.me,
+    tasks: data.tasks,
   }));
   const [text, setText] = useState(() => localStorage.getItem(draftKey) ?? "");
   const files = useAttachments({ incoming, onConsumed, taskId: channel.task_id });
   const [busy, setBusy] = useState(false);
-  const [mentionQuery, setMentionQuery] = useState<string | null>(null);
+  // `@` brings a teammate in, `#` points at a task. One menu, one keyboard.
+  const [mention, setMention] = useState<{ sigil: string; query: string } | null>(null);
   const [mentionIndex, setMentionIndex] = useState(0);
   const box = useRef<HTMLTextAreaElement>(null);
   const wrap = useRef<HTMLDivElement>(null);
@@ -983,27 +988,42 @@ function ComposerBox({
     }
   };
 
-  const candidates =
-    mentionQuery === null
-      ? []
-      : members
-          .filter(
-            (member) =>
-              member.handle.startsWith(mentionQuery.toLowerCase()) &&
-              member.id !== me?.id,
-          )
-          .slice(0, 6);
-
-  const applyMention = (handle: string) => {
-    setText((current) => current.replace(/@[\w-]*$/, `@${handle} `));
-    setMentionQuery(null);
+  const candidates = useMemo(() => {
+    if (!mention) return [];
+    const query = mention.query.toLowerCase();
+    if (mention.sigil === "#") {
+      // The key is the mention: what lands in the message is what every other
+      // surface already writes, so the reference reads the same everywhere.
+      return matchTasks(tasks, query).map((task) => ({
+        id: task.id,
+        insert: `${task.key} `,
+        name: task.title,
+        sub: `${task.key} · ${statusLabel(task.status)}`,
+        member: undefined as Member | undefined,
+      }));
+    }
+    return members
+      .filter((member) => member.handle.startsWith(query) && member.id !== me?.id)
+      .slice(0, 6)
+      .map((member) => ({
+        id: member.id,
+        insert: `@${member.handle} `,
+        name: member.display_name,
+        sub: `@${member.handle}${member.kind === "agent" ? " · agent" : ""}`,
+        member,
+      }));
+  }, [mention, members, me?.id, tasks]);
+
+  const applyMention = (insert: string) => {
+    setText((current) => current.replace(/[@#][\w-]*$/, insert));
+    setMention(null);
     box.current?.focus();
   };
 
   const onChange = (value: string) => {
     setText(value);
-    const match = value.match(/@([\w-]*)$/);
-    setMentionQuery(match ? match[1] : null);
+    const match = value.match(/([@#])([\w-]*)$/);
+    setMention(match ? { sigil: match[1], query: match[2] } : null);
     setMentionIndex(0);
     store.typing(channel.id);
   };
@@ -1047,20 +1067,21 @@ function ComposerBox({
 
       {candidates.length > 0 && (
         <div className="mention-menu">
-          {candidates.map((member, index) => (
+          {candidates.map((candidate, index) => (
             <button
-              key={member.id}
+              key={candidate.id}
               className={`row${index === mentionIndex ? " active" : ""}`}
               onMouseEnter={() => setMentionIndex(index)}
-              onClick={() => applyMention(member.handle)}
+              onClick={() => applyMention(candidate.insert)}
             >
-              <Avatar member={member} size={22} />
+              {candidate.member ? (
+                <Avatar member={candidate.member} size={22} />
+              ) : (
+                <TasksIcon size={16} />
+              )}
               <span className="grow">
-                <span className="name">{member.display_name}</span>
-                <span className="sub">
-                  @{member.handle}
-                  {member.kind === "agent" ? " · agent" : ""}
-                </span>
+                <span className="name">{candidate.name}</span>
+                <span className="sub">{candidate.sub}</span>
               </span>
             </button>
           ))}
@@ -1114,11 +1135,11 @@ function ComposerBox({
               }
               if (event.key === "Tab" || (event.key === "Enter" && !event.shiftKey)) {
                 event.preventDefault();
-                applyMention(candidates[mentionIndex].handle);
+                applyMention(candidates[mentionIndex].insert);
                 return;
               }
               if (event.key === "Escape") {
-                setMentionQuery(null);
+                setMention(null);
                 return;
               }
             }
diff --git a/desktop/src/components/Markdown.tsx b/desktop/src/components/Markdown.tsx
index eac0ce0..99948a1 100644
--- a/desktop/src/components/Markdown.tsx
+++ b/desktop/src/components/Markdown.tsx
@@ -9,6 +9,8 @@ import type { ReactNode } from "react";
 import { parseBlocks, renderInline } from "../lib/markdown";
 import type { InlineOptions } from "../lib/markdown";
 import { CheckIcon, CopyIcon } from "./icons";
+import { useNavigation } from "./common";
+import { useAppSelector } from "../lib/store";
 
 export const Markdown = memo(function Markdown({
   body,
@@ -23,7 +25,18 @@ export const Markdown = memo(function Markdown({
   compact?: boolean;
 }) {
   const blocks = useMemo(() => parseBlocks(body), [body]);
-  const options: InlineOptions = useMemo(() => ({ handles }), [handles]);
+  const { go } = useNavigation();
+  // Read here rather than handed down: a task key means the same task in every
+  // surface that renders a message, and the list only moves when a task does.
+  const allTasks = useAppSelector((data) => data.tasks);
+  const tasks = useMemo(
+    () => new Map(allTasks.map((task) => [task.key.toUpperCase(), task.id])),
+    [allTasks],
+  );
+  const options: InlineOptions = useMemo(
+    () => ({ handles, tasks, onTask: (id: string) => go({ kind: "task", id }) }),
+    [handles, tasks, go],
+  );
 
   return (
     <div className={`md${compact ? " compact" : ""}${className ? ` ${className}` : ""}`}>
diff --git a/desktop/src/lib/markdown.tsx b/desktop/src/lib/markdown.tsx
index d6fa13f..03f729d 100644
--- a/desktop/src/lib/markdown.tsx
+++ b/desktop/src/lib/markdown.tsx
@@ -8,6 +8,7 @@
 // table has to render as something calm rather than flickering into garbage.
 
 import type { ReactNode } from "react";
+import { TASK_KEY } from "@client/mentions";
 
 // --- blocks -----------------------------------------------------------------
 
@@ -346,6 +347,9 @@ export interface InlineOptions {
   /// Handles that resolve to a real member, so `@nobody` stays plain text.
   handles?: Set<string>;
   onMention?: (handle: string) => void;
+  /// Uppercased task keys to task ids, so `PW-999` stays plain text.
+  tasks?: Map<string, string>;
+  onTask?: (taskId: string) => void;
 }
 
 /// Only schemes that can't execute anything. A `javascript:` href in an agent's
@@ -371,6 +375,7 @@ const INLINE = new RegExp(
     "<(https?://[^>\\s]+)>", // autolink
     "(?<![\\w/])(https?://[^\\s<>()\\[\\]]+[^\\s<>()\\[\\].,;:!?'\"])", // bare url
     "@([a-z0-9][\\w-]*)", // mention
+    TASK_KEY.source, // task mention: PW-42
   ].join("|"),
   "gi",
 );
@@ -423,6 +428,7 @@ export function renderInline(
       autolink,
       bareUrl,
       mention,
+      taskKey,
     ] = match;
 
     if (code !== undefined) {
@@ -484,6 +490,26 @@ export function renderInline(
           <span key={k}>@{mention}</span>
         ),
       );
+    } else if (taskKey !== undefined) {
+      // Every surface writes the key the same way, so recognising it here makes
+      // a task someone typed and a task an agent cited the same live reference.
+      const taskId = options.tasks?.get(taskKey.toUpperCase());
+      push(
+        taskId ? (
+          <span
+            key={k}
+            className="mention task"
+            onClick={(event) => {
+              event.stopPropagation();
+              options.onTask?.(taskId);
+            }}
+          >
+            {taskKey.toUpperCase()}
+          </span>
+        ) : (
+          <span key={k}>{taskKey}</span>
+        ),
+      );
     }
   }
 
diff --git a/desktop/src/styles.css b/desktop/src/styles.css
index c7a434c..9feda87 100644
--- a/desktop/src/styles.css
+++ b/desktop/src/styles.css
@@ -1046,6 +1046,9 @@ body.resizing {
   color: var(--accent);
   font-weight: 550;
 }
+.mention.task {
+  cursor: pointer;
+}
 
 /* --- composer ------------------------------------------------------------ */
 
diff --git a/mobile/package.json b/mobile/package.json
index 352c91d..5866356 100644
--- a/mobile/package.json
+++ b/mobile/package.json
@@ -8,7 +8,7 @@
     "android": "expo run:android",
     "ios": "expo run:ios",
     "typecheck": "tsc --noEmit",
-    "test": "node --test --experimental-strip-types ../client/mobile-store-reducer.test.ts ../client/run-activity.test.ts ../client/scroll.test.ts src/lib/format.test.ts src/lib/workspace-cache.test.ts",
+    "test": "node --test --experimental-strip-types ../client/mentions.test.ts ../client/mobile-store-reducer.test.ts ../client/run-activity.test.ts ../client/scroll.test.ts src/lib/format.test.ts src/lib/workspace-cache.test.ts",
     "export": "expo export --platform all"
   },
   "dependencies": {
diff --git a/mobile/src/components/Composer.tsx b/mobile/src/components/Composer.tsx
index 7a552c6..20b3f1d 100644
--- a/mobile/src/components/Composer.tsx
+++ b/mobile/src/components/Composer.tsx
@@ -10,6 +10,7 @@ import {
   View,
 } from "react-native";
 
+import { matchTasks } from "@client/mentions";
 import type { Id, Message } from "@client/types";
 import { useDictation } from "@/lib/dictation";
 import { useWorkspace, useWorkspaceStore } from "@/lib/store";
@@ -42,14 +43,30 @@ export function Composer({
   const typingAt = useRef(0);
   const input = useRef<TextInput>(null);
   const members = workspace.bootstrap?.members ?? [];
+  const tasks = workspace.bootstrap?.tasks ?? [];
+  // `@` brings a teammate in, `#` points at a task. A task mention is its key,
+  // the same reference every other surface writes.
   const mention = useMemo(() => {
-    const match = text.match(/(?:^|\s)@([\w-]*)$/);
+    const match = text.match(/(?:^|\s)([@#])([\w-]*)$/);
     if (!match) return [];
-    const query = match[1].toLowerCase();
+    const query = match[2].toLowerCase();
+    if (match[1] === "#")
+      return matchTasks(tasks, query, 5).map((task) => ({
+        id: task.id,
+        insert: `${task.key} `,
+        name: task.title,
+        sub: task.key,
+      }));
     return members
       .filter((member) => member.handle.toLowerCase().startsWith(query))
-      .slice(0, 5);
-  }, [members, text]);
+      .slice(0, 5)
+      .map((member) => ({
+        id: member.id,
+        insert: `@${member.handle} `,
+        name: member.display_name,
+        sub: `@${member.handle}`,
+      }));
+  }, [members, tasks, text]);
   const dictation = useDictation((value) => store.setDraft(draftKey, value));
   const offline = workspace.connection !== "live";
   const empty = !text.trim() && images.pending.length === 0;
@@ -67,8 +84,8 @@ export function Composer({
     }
   };
 
-  const insertMention = (handle: string) => {
-    change(text.replace(/@[\w-]*$/, `@${handle} `));
+  const insertMention = (insert: string) => {
+    change(text.replace(/[@#][\w-]*$/, insert));
   };
 
   const send = async () => {
@@ -103,10 +120,10 @@ export function Composer({
       <View style={[styles.wrap, { backgroundColor: theme.bg, borderTopColor: theme.line }]}>
         {mention.length ? (
           <View style={[styles.mentions, { backgroundColor: theme.raised, borderColor: theme.line }]}>
-            {mention.map((member) => (
-              <Pressable accessibilityRole="button" key={member.id} onPress={() => insertMention(member.handle)} style={styles.mentionRow}>
-                <Text style={{ color: theme.text, fontWeight: "600" }}>{member.display_name}</Text>
-                <Text style={{ color: theme.muted }}>@{member.handle}</Text>
+            {mention.map((candidate) => (
+              <Pressable accessibilityRole="button" key={candidate.id} onPress={() => insertMention(candidate.insert)} style={styles.mentionRow}>
+                <Text numberOfLines={1} style={{ color: theme.text, flexShrink: 1, fontWeight: "600" }}>{candidate.name}</Text>
+                <Text style={{ color: theme.muted }}>{candidate.sub}</Text>
               </Pressable>
             ))}
           </View>