diff --git a/changelog.d/1646-room-busy-ack.fixed.md b/changelog.d/1646-room-busy-ack.fixed.md
new file mode 100644
index 000000000..cc26d53a3
--- /dev/null
+++ b/changelog.d/1646-room-busy-ack.fixed.md
@@ -0,0 +1 @@
+A member Bot busy with a tool in a group chat now acknowledges a person's line there, the same one short line the own-chat path already speaks (`#1646`). The ack is keyed by the member's room Session and drawn on that member's row in the room flow — the host's line, or the same blinking indicator #1656 draws while that line is still on its way, never a fixed sentence; a line that reaches no running member, and every own-chat case, is unchanged.
diff --git a/core/client.js b/core/client.js
index c21486ffb..2136cb947 100644
--- a/core/client.js
+++ b/core/client.js
@@ -9867,6 +9867,16 @@ function busyAckVisible({ hostAck, pendingBusy, streamingText }) {
   if (streamingText) return false;
   return busyAckText(hostAck) !== "" || pendingBusy === true;
 }
+function roomBusyAck(room2) {
+  const entries2 = Object.entries(room2?.busyAcks ?? {}).filter(([, ack2]) => ack2 !== void 0 && ack2 !== null);
+  if (entries2.length === 0) return null;
+  const [botId, ack] = entries2.sort((a, b) => (b[1].at ?? 0) - (a[1].at ?? 0))[0];
+  return { botId, text: busyAckText(ack), at: ack.at ?? 0 };
+}
+function roomBusyAckVisible({ ack, pendingBusy }) {
+  if (ack === null || ack === void 0) return false;
+  return ack.text !== "" || pendingBusy === true;
+}
 
 // src/client/busy-ack.js
 var import_react17 = require("react");
@@ -9898,15 +9908,17 @@ function useRunningHost2(active) {
 }
 function BusyAckBubble({ sessionId, useRoster, useBusyAcks, useSessionStatus, useSession, useLive }) {
   const roster = useRoster((value) => value);
+  const room2 = roster.roomsById?.[sessionId];
+  const memberAck = room2 ? roomBusyAck(room2) : null;
   const hostAck = useBusyAcks((map) => map?.[sessionId] ?? null);
   const running = useSessionStatus((map) => map.get(sessionId)?.running === true);
   const pendingBusy = useSession((snapshot) => pendingBusyPlacement(snapshot?.pendingSubmissions));
   const streamingText = useLive((state) => Object.values(state[sessionId] ?? {}).some((entry) => entry?.text));
-  const visible = running && busyAckVisible({ hostAck, pendingBusy, streamingText });
-  const bot = roster.byId[sessionId];
+  const visible = room2 ? roomBusyAckVisible({ ack: memberAck, pendingBusy }) : running && busyAckVisible({ hostAck, pendingBusy, streamingText });
+  const bot = room2 ? roster.byId[memberAck?.botId] : roster.byId[sessionId];
   const host = useRunningHost2(visible);
   const shown = (0, import_react17.useRef)(null);
-  if (visible) shown.current = { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() };
+  if (visible) shown.current = room2 ? { text: memberAck?.text ?? "", at: memberAck?.at ?? Date.now() } : { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() };
   const text = shown.current?.text ?? "";
   if (!visible || !host || !shown.current || !bot) return null;
   return (0, import_react_dom4.createPortal)((0, import_react17.createElement)(
diff --git a/core/src/client/busy-ack-logic.js b/core/src/client/busy-ack-logic.js
index 4a665bcd8..ce89dc862 100644
--- a/core/src/client/busy-ack-logic.js
+++ b/core/src/client/busy-ack-logic.js
@@ -19,3 +19,21 @@ export function busyAckVisible({ hostAck, pendingBusy, streamingText }) {
   if (streamingText) return false
   return busyAckText(hostAck) !== '' || pendingBusy === true
 }
+
+// The ack a room flow draws on its member's row (#1646). The host publishes `room.busyAcks`
+// keyed by the member while that member's turn runs in the room; an entry whose text is still
+// empty means the host's line is not composed yet, which the client draws the way #1656 draws
+// a pending own-chat ack: the mark and the blinking indicator, no fixed sentence.
+export function roomBusyAck(room) {
+  const entries = Object.entries(room?.busyAcks ?? {}).filter(([, ack]) => ack !== undefined && ack !== null)
+  if (entries.length === 0) return null
+  const [botId, ack] = entries.sort((a, b) => (b[1].at ?? 0) - (a[1].at ?? 0))[0]
+  return { botId, text: busyAckText(ack), at: ack.at ?? 0 }
+}
+
+// A room's ack is drawn while that member's turn runs: the host's line as text, or the blinking
+// indicator alone while the person's line is still queued in the room and the line is not here.
+export function roomBusyAckVisible({ ack, pendingBusy }) {
+  if (ack === null || ack === undefined) return false
+  return ack.text !== '' || pendingBusy === true
+}
diff --git a/core/src/client/busy-ack.js b/core/src/client/busy-ack.js
index d88908352..ad309e9de 100644
--- a/core/src/client/busy-ack.js
+++ b/core/src/client/busy-ack.js
@@ -2,9 +2,11 @@ import { createElement as h, useEffect, useRef, useState } from 'react'
 import { createPortal } from 'react-dom'
 import { BotMark } from './mark.js'
 import { RUNNING_HOST } from './activity-row.js'
-import { busyAckText, busyAckVisible, pendingBusyPlacement } from './busy-ack-logic.js'
+import { busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible } from './busy-ack-logic.js'
 
-export { busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement } from './busy-ack-logic.js'
+export {
+  busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible,
+} from './busy-ack-logic.js'
 
 // Spoken busy-ack (#1584): when a human send is accepted while the Bot is running
 // (host live busyAcks, or a local pending queue/steer submission), show one short
@@ -32,15 +34,23 @@ function useRunningHost(active) {
 
 export function BusyAckBubble({ sessionId, useRoster, useBusyAcks, useSessionStatus, useSession, useLive }) {
   const roster = useRoster(value => value)
+  const room = roster.roomsById?.[sessionId]
+  // A group draws one member's ack on the row that member's turn runs in (#1646); its
+  // Session is not the conversation being shown, so `busyAcks[sessionId]` never has it.
+  const memberAck = room ? roomBusyAck(room) : null
   const hostAck = useBusyAcks(map => map?.[sessionId] ?? null)
   const running = useSessionStatus(map => map.get(sessionId)?.running === true)
   const pendingBusy = useSession(snapshot => pendingBusyPlacement(snapshot?.pendingSubmissions))
   const streamingText = useLive(state => Object.values(state[sessionId] ?? {}).some(entry => entry?.text))
-  const visible = running && busyAckVisible({ hostAck, pendingBusy, streamingText })
-  const bot = roster.byId[sessionId]
+  const visible = room
+    ? roomBusyAckVisible({ ack: memberAck, pendingBusy })
+    : running && busyAckVisible({ hostAck, pendingBusy, streamingText })
+  const bot = room ? roster.byId[memberAck?.botId] : roster.byId[sessionId]
   const host = useRunningHost(visible)
   const shown = useRef(null)
-  if (visible) shown.current = { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() }
+  if (visible) shown.current = room
+    ? { text: memberAck?.text ?? '', at: memberAck?.at ?? Date.now() }
+    : { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() }
   const text = shown.current?.text ?? ''
   if (!visible || !host || !shown.current || !bot) return null
   return createPortal(h('div', {
diff --git a/core/src/host/busy-ack.js b/core/src/host/busy-ack.js
index 2cd736d31..f15e603a4 100644
--- a/core/src/host/busy-ack.js
+++ b/core/src/host/busy-ack.js
@@ -129,6 +129,19 @@ export function shouldNoteBusyAck({ sourceKind, turnRunning, ownChat }) {
   return sourceKind === 'user' && turnRunning === true && ownChat === true
 }
 
+// A person's line reaching a member's group Session (#1646). A round relays it as
+// `role: 'room'` with no Bot sender: a Bot's own call carries `senderSessionId`, an
+// @-mention by another Bot carries `askedBy`, and a friend's Bot carries `remote`.
+export function isHumanRoomLine(source) {
+  return source?.role === 'room'
+    && source.senderSessionId === undefined
+    && source.askedBy === undefined
+    && source.remote === undefined
+}
+
+// The relay prefix delivery.js puts on the line; the ack quotes the person's text, not it.
+const relayHeader = /^\[[^\]\n]*\]\r?\n/
+
 const textOf = (content) => {
   if (typeof content === 'string') return content
   if (!Array.isArray(content)) return ''
@@ -145,6 +158,9 @@ export function install(rt) {
 
   const turnRunning = sessionId => rt.live?.get(sessionId)?.turn !== undefined
   const ownChat = sessionId => rt.chatOwners?.has(sessionId) === true
+  const groupSession = sessionId => rt.groupOwners?.has(sessionId) === true
+  /** A person's line into this member's running group Session (#1646), once only. */
+  const roomLine = (sessionId, source) => groupSession(sessionId) && isHumanRoomLine(source)
 
   const note = (sessionId, message) => {
     const now = Date.now()
@@ -173,12 +189,12 @@ export function install(rt) {
     const id = session?.id
     if (id === undefined || event?.type === undefined) return
     if (event.type === 'user/message') {
-      if (!shouldNoteBusyAck({
-        sourceKind: event.data?.source?.kind,
-        turnRunning: turnRunning(id),
-        ownChat: ownChat(id),
-      })) return
-      note(id, textOf(event.data?.content ?? event.data?.message?.content))
+      const source = event.data?.source
+      const room = roomLine(id, source)
+      const own = shouldNoteBusyAck({ sourceKind: source?.kind, turnRunning: turnRunning(id), ownChat: ownChat(id) })
+      if (!own && !(room && turnRunning(id))) return
+      const text = textOf(event.data?.content ?? event.data?.message?.content)
+      note(id, room ? text.replace(relayHeader, '') : text)
       return
     }
     if (event.type === 'assistant/message') {
@@ -196,6 +212,15 @@ export function install(rt) {
 
   Object.assign(rt, {
     busyAcksView: () => Object.fromEntries([...acks].map(([id, ack]) => [id, { text: ack.text, at: ack.at }])),
+    // A room draws the ack on its running member's row (#1646), so its flow is keyed by
+    // member, not by the Session a person cannot see. A member whose turn runs before its
+    // line is composed is published with an empty text: the client draws the same blinking
+    // indicator an own-chat pending ack draws (#1656), never a fixed sentence.
+    roomBusyAcksView: sessions => Object.fromEntries(Object.entries(sessions ?? {}).flatMap(([botId, sessionId]) => {
+      if (!turnRunning(sessionId)) return []
+      const ack = acks.get(sessionId)
+      return [[botId, ack === undefined ? { text: '', at: 0 } : { text: ack.text, at: ack.at }]]
+    })),
     noteBusyAck: note,
     clearBusyAck: clear,
   })
diff --git a/core/src/host/channel.js b/core/src/host/channel.js
index d7d51fb34..95a36c048 100644
--- a/core/src/host/channel.js
+++ b/core/src/host/channel.js
@@ -159,6 +159,8 @@ export function install(rt) {
         ...presented,
         log: undefined,
         parts,
+        // A member's busy ack, for the row that member's turn draws in the room flow (#1646).
+        busyAcks: rt.roomBusyAcksView?.(sessions) ?? {},
         pendingApprovals: pending,
         pendingCount: pending.length,
         ...(last ? { preview: previewWho } : {}),
diff --git a/core/test/busy-ack-client.test.js b/core/test/busy-ack-client.test.js
index 71f9a6d3c..b7e8603b3 100644
--- a/core/test/busy-ack-client.test.js
+++ b/core/test/busy-ack-client.test.js
@@ -3,7 +3,9 @@ import { readFileSync } from 'node:fs'
 import { test } from 'node:test'
 import * as logic from '../src/client/busy-ack-logic.js'
 
-const { busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement } = logic
+const {
+  busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible,
+} = logic
 
 test('pendingBusyPlacement is true for queued or steering submissions', () => {
   assert.equal(pendingBusyPlacement([]), false)
@@ -43,3 +45,27 @@ test('#1656: the canned sentence is not shipped anywhere in the client', () => {
   assert.match(bubble, /'aria-busy': text \? undefined : 'true'/)
   assert.match(bubble, /@keyframes bt-busy-blink/)
 })
+
+test('a room ack is the running member\'s, keyed by the member the host noted (#1646)', () => {
+  assert.equal(roomBusyAck(undefined), null)
+  assert.equal(roomBusyAck({}), null)
+  assert.equal(roomBusyAck({ busyAcks: {} }), null)
+  assert.deepEqual(roomBusyAck({ busyAcks: { b: { text: '收到', at: 7 } } }), { botId: 'b', text: '收到', at: 7 })
+  // The host publishes the member as soon as its turn runs; empty text means the ack line is
+  // still being composed, and the client draws the pending dots for it (#1656, #1646).
+  assert.deepEqual(roomBusyAck({ busyAcks: { b: { text: '', at: 1 } } }), { botId: 'b', text: '', at: 1 })
+  assert.equal(roomBusyAck({ busyAcks: { b: { text: '   ', at: 1 } } }).text, '')
+  // Only the speaking member has one; the newest wins if two ever land together.
+  assert.deepEqual(
+    roomBusyAck({ busyAcks: { a: { text: 'older', at: 5 }, b: { text: 'newer', at: 9 } } }),
+    { botId: 'b', text: 'newer', at: 9 },
+  )
+})
+
+test('a room ack shows its line, or the blinking dots while the person\'s line is still queued (#1646)', () => {
+  assert.equal(roomBusyAckVisible({ ack: null, pendingBusy: true }), false)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '', at: 1 }, pendingBusy: false }), false)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '', at: 1 }, pendingBusy: true }), true)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '收到', at: 1 }, pendingBusy: false }), true)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '收到', at: 1 }, pendingBusy: true }), true)
+})
diff --git a/core/test/busy-ack.test.js b/core/test/busy-ack.test.js
index 9700f81d4..677a1f1f6 100644
--- a/core/test/busy-ack.test.js
+++ b/core/test/busy-ack.test.js
@@ -1,8 +1,12 @@
 import assert from 'node:assert/strict'
+import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
 import { test } from 'node:test'
 import {
-  ackLanguage, composeBusyAck, doingOf, shouldNoteBusyAck, topicOf,
+  ackLanguage, composeBusyAck, doingOf, install as installBusyAck, shouldNoteBusyAck, topicOf,
 } from '../src/host/busy-ack.js'
+import { install as installStore } from '../src/host/store.js'
 
 // The pre-#1629 canned lines; an ack must never be either verbatim.
 const OLD_ZH = '收到，我先记着，手头忙完再详细回你。'
@@ -151,3 +155,137 @@ test('a {t} typed in the message is quoted back verbatim, with and without a run
     }
   }
 })
+
+// --- The room side (#1646) -------------------------------------------------
+// A group's member speaks from a hidden Session (`room.sessions[botId]`), and the person's line
+// reaches it as a relayed `role: 'room'` message, not as `source.kind === 'user'`. These tests
+// run the real store beside the real busy-ack install, so `chatOwners` and `groupOwners` are the
+// host's own indexes; only `live` is seeded, as turns.js would have recorded a running turn.
+const roomHost = async (t) => {
+  const dir = mkdtempSync(join(tmpdir(), 'ds-bot-busy-ack-room-'))
+  const statePath = join(dir, 'state.json')
+  writeFileSync(statePath, JSON.stringify({
+    version: 2,
+    mainBotIds: ['a'],
+    members: { 'owner-1': { id: 'owner-1', createdAt: 1, designatedChiefId: 'a' } },
+    bots: {
+      a: { id: 'a', name: 'Chief', sessionId: 'a', ownerId: 'owner-1', createdAt: 1 },
+      b: { id: 'b', name: 'Writer', sessionId: 'b', ownerId: 'owner-1', createdAt: 2 },
+    },
+    rooms: {
+      r1: {
+        id: 'r1', name: 'Ops', members: ['a', 'b'], mode: 'admin', admin: 'b', named: true,
+        sessions: { b: 'gb' }, log: [], seq: 0, seen: {},
+      },
+    },
+    agents: {}, exchanges: [], exchangeTurns: {}, questions: {}, prefs: {}, revision: 0,
+  }))
+  const disposers = []
+  const listeners = new Map()
+  const ctx = {
+    logger: { warn() {}, info() {} },
+    effect(execute) { const dispose = execute(); if (typeof dispose === 'function') disposers.push(dispose) },
+    on(name, fn) { const list = listeners.get(name) ?? listeners.set(name, []).get(name); list.push(fn); return () => {} },
+  }
+  const rt = {
+    ctx, home: dir, statePath,
+    autoRoomName: () => 'Room', retitleRoom: async () => {}, dropGroupSession: () => {}, warn: () => {},
+  }
+  installStore(rt)
+  await rt.load()
+  rt.live = new Map()
+  installBusyAck(rt)
+  t.after(() => {
+    for (const dispose of disposers.splice(0)) dispose()
+    rmSync(dir, { recursive: true, force: true, maxRetries: 5 })
+  })
+  const fire = (name, ...args) => { for (const fn of listeners.get(name) ?? []) fn(...args) }
+  const emit = (id, type, data) => fire('session/event', { id }, { type, seq: 1, data })
+  return { rt, emit, fire, chatOwners: rt.chatOwners, groupOwners: rt.groupOwners }
+}
+
+// The relay a person's line takes into a member's group Session (delivery.js + groups.js).
+const roomSay = text => ({
+  type: 'user/message',
+  data: {
+    source: { kind: 'bot', form: 'relay', role: 'room', roomId: 'r1', exchangeId: 'x1', senderName: 'You', hop: 0 },
+    content: [{ type: 'text', text: `[Group chat "Ops" · new message from the user]\n${text}` }],
+  },
+})
+
+test('the indexes the room case leans on are the store\'s own (#1646)', async (t) => {
+  const host = await roomHost(t)
+  assert.equal(host.chatOwners.get('b'), 'b')
+  assert.equal(host.chatOwners.has('gb'), false)
+  assert.deepEqual(host.groupOwners.get('gb'), { botId: 'b', roomId: 'r1' })
+})
+
+test('a room line steered into a running member\'s Session notes one ack for that Session (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('gb', { turn: 1, tool: 'bash' })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  host.emit('gb', 'user/message', roomSay('帮我把周报再改一下').data)
+  const acks = host.rt.busyAcksView()
+  assert.deepEqual(Object.keys(acks), ['gb'])
+  assert.match(acks.gb.text, /周报/)
+  assert.match(acks.gb.text, /跑命令/)
+  assert.doesNotMatch(acks.gb.text, /Group chat/)
+  // Coalesced: a second line inside the window keeps the one ack.
+  const at = acks.gb.at
+  host.emit('gb', 'user/message', roomSay('again').data)
+  assert.deepEqual(Object.keys(host.rt.busyAcksView()), ['gb'])
+  assert.equal(host.rt.busyAcksView().gb.text, acks.gb.text)
+  assert.ok(host.rt.busyAcksView().gb.at >= at)
+  // No ack survives the turn.
+  host.emit('gb', 'turn/end', { turn: 1, reason: { kind: 'completed' } })
+  assert.deepEqual(host.rt.busyAcksView(), {})
+  host.rt.live.set('gb', { turn: 2 })
+  host.emit('gb', 'user/message', roomSay('还在吗').data)
+  assert.ok(host.rt.busyAcksView().gb)
+  host.fire('agent/status', { agent: { session: { id: 'gb' } }, status: 'idle' })
+  assert.deepEqual(host.rt.busyAcksView(), {})
+})
+
+test('a room line to an idle member, and a line another Bot relayed, note nothing (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.emit('gb', 'user/message', roomSay('没有 turn').data)
+  assert.deepEqual(host.rt.busyAcksView(), {})
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  const fromBot = roomSay('another Bot called you')
+  fromBot.data.source.senderSessionId = 'a'
+  fromBot.data.source.askedBy = 'a'
+  host.emit('gb', 'user/message', fromBot.data)
+  assert.deepEqual(host.rt.busyAcksView(), {})
+})
+
+test('the room view names a running member before its line lands, then carries the line (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  // The member's turn is already running while the person's line is still being composed:
+  // an empty text, which the client draws as the pending blinking indicator, no sentence.
+  assert.deepEqual(host.rt.roomBusyAcksView({ b: 'gb' }), { b: { text: '', at: 0 } })
+  host.emit('gb', 'user/message', roomSay('帮我把周报再改一下').data)
+  assert.match(host.rt.roomBusyAcksView({ b: 'gb' }).b.text, /周报/)
+  assert.doesNotMatch(host.rt.roomBusyAcksView({ b: 'gb' }).b.text, /Group chat/)
+  // No running turn, no entry; an empty member map stays empty.
+  host.rt.live.delete('gb')
+  assert.deepEqual(host.rt.roomBusyAcksView({ b: 'gb' }), {})
+  assert.deepEqual(host.rt.roomBusyAcksView({}), {})
+})
+
+test('the own-chat ack is unchanged beside the room path (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('b', { turn: 1, tool: 'bash' })
+  host.emit('b', 'turn/start', { turn: 1 })
+  host.emit('b', 'user/message', say('check the logs').data)
+  const acks = host.rt.busyAcksView()
+  assert.deepEqual(Object.keys(acks), ['b'])
+  assert.match(acks.b.text, /check the logs/)
+  // The same Session id space: a room line in the member's group Session is its own key.
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  host.emit('gb', 'user/message', roomSay('帮我看日志').data)
+  assert.deepEqual(Object.keys(host.rt.busyAcksView()).sort(), ['b', 'gb'])
+})
diff --git a/docs/subsystems/core-client.md b/docs/subsystems/core-client.md
index 03bb91062..6d790375d 100644
--- a/docs/subsystems/core-client.md
+++ b/docs/subsystems/core-client.md
@@ -122,6 +122,14 @@ The overlay (`flybot-slots.js` `FlyBotApprovals`) is the fallback, not a second
 
 When a human message is accepted while the Bot is already running (DSH queue or steer, including long background job waits), `BusyAckBubble` (`src/client/busy-ack.js`, mounted from `HeaderPill` next to the activity row) draws one short bot bubble promptly: host live `busyAcks` from `busy-ack.js` on the host, or a local pending submission with placement `queued` / `steering` (`busy-ack-logic.js`). The text is the host's composed line (topic + running tool, message language, never the previous one — [#1629](https://github.com/ThinkFlowLab/FlyBot/issues/1629)); with only a local pending submission (the host ack not here yet) the bubble holds the Bot's mark and a short blinking indicator, no fixed sentence, and the host's line replaces it when it lands ([#1656](https://github.com/ThinkFlowLab/FlyBot/issues/1656)). It hides once spoken assistant text streams. Related but separate: [#1509](https://github.com/ThinkFlowLab/FlyBot/issues/1509) (Steer does not abort a tool wait). Covered by `core/test/busy-ack-client.test.js`.
 
+A group room is acknowledged where its round is drawn (#1646). The open chat is the room, not the member's Session, so `BusyAckBubble` reads `roomBusyAck(room)` — the newest entry of `room.busyAcks` — and draws it as one bot bubble in the room flow's running row (`[data-chat-running]`) under that member's `BotMark`. Three rules decide what it shows:
+
+- **Only a running member's turn.** The host publishes `room.busyAcks` per member id through `roomBusyAcksView(sessions)`, which names only members whose turn is still running; a room with no such entry draws nothing. A member whose turn is running before its line is composed is published with an empty text, and the room draws the same blinking indicator an own-chat pending ack draws ([#1656](https://github.com/ThinkFlowLab/FlyBot/issues/1656)) — the mark and the dots, no sentence — until the host's line replaces it. On the host the ack is cleared by `turn/end` and by `agent/status` `idle`, so a finished or idle member loses the row instead of leaving a stale line.
+- **Only a person's line.** A room line counts when `isHumanRoomLine(source)` holds: `role: 'room'` with no `senderSessionId` (the Bot's own call), no `askedBy` (another Bot's @-mention) and no `remote` (a friend's Bot). A Bot talking in the room is acknowledged by nothing.
+- **The person's words, not the relay header.** The host strips the `[Group chat "…" · new message from the user]` header `delivery.js` puts on a room line before composing, so the ack quotes what the person typed.
+
+The member's own chat keeps its `busyAcks[sessionId]` bubble and its visibility rules unchanged; that path and its line are untouched. The fixed fallback sentence `#1584` used is gone (#1656), in the room as in the own chat: a pending ack is the blinking indicator, and the host's composed line is the text. The host side (`isHumanRoomLine`, the relay-header strip, `roomBusyAcksView`, `channel.js` `busyAcks`) is in `core-host.md`.
+
 ### Face-room held bubble and overview
 
 - A face-to-face own message uses `data-held` on `.bt-umsg` while that room's `pendingCount > 0`: dashed, mixed user-surface, `--bt-ink` (not the finished sent user bubble). Incoming lines are unchanged. Face-to-face `GroupOverview` hides the Usage row.
diff --git a/docs/subsystems/core-host.md b/docs/subsystems/core-host.md
index 2587bd2b8..160bde3ce 100644
--- a/docs/subsystems/core-host.md
+++ b/docs/subsystems/core-host.md
@@ -405,7 +405,7 @@ Work a member hands a Bot with `message_bot` from its group Session runs in a hi
 - A friend's line in a Bot's own chat (#420): `deliver()` (`noteFriendLine`) stamps the receiving Bot with `friendLineAt` (published in the roster, so the save moves the revision) and keeps the senders seen per Bot in `state.remoteContacts[botId][handle]` (host only, capped at 200, dropped with the Bot). A sender's first line carries `source.remote.firstContact`. Group lines, and re-deliveries (`deferred`, `resumed`, `retried`, `resent`), stamp nothing. Covered by `core/test/flybot.test.js`.
 ## Busy-send acknowledgment (#1584)
 
-When a human `user/message` lands in a Bot's own chat while that Session already has a live turn, the host records a short spoken acknowledgment on the live payload (`busyAcks`). The line is composed on the host with no model call ([#1629](https://github.com/ThinkFlowLab/FlyBot/issues/1629)): it echoes a clipped topic from the message verbatim — a `{t}` / `{d}` the person typed is quoted as typed, not treated as markup ([#1634](https://github.com/ThinkFlowLab/FlyBot/issues/1634)) — and the running tool in words (`bash` → running a command), follows the message's language, rotates its wording, and never repeats the chat's previous ack. The client draws it as one bot bubble (and also from a local pending queue/steer submission) so the chat is not silent while a blocking job wait holds the next step. Related but separate: [#1509](https://github.com/ThinkFlowLab/FlyBot/issues/1509) (Steer does not abort a tool wait). Host: `core/src/host/busy-ack.js`. Client: `core/src/client/busy-ack.js`. Tests: `core/test/busy-ack.test.js`, `core/test/busy-ack-client.test.js`.
+When a human `user/message` lands in a Bot's own chat while that Session already has a live turn, the host records a short spoken acknowledgment on the live payload (`busyAcks`); a person's line relayed into a running member's group Session (`role: 'room'`, no Bot sender) earns the same one, keyed by that member Session and published per member on the room as `busyAcks` so the room draws it on the member's row ([#1646](https://github.com/ThinkFlowLab/FlyBot/issues/1646)). The line is composed on the host with no model call ([#1629](https://github.com/ThinkFlowLab/FlyBot/issues/1629)): it echoes a clipped topic from the message verbatim — a `{t}` / `{d}` the person typed is quoted as typed, not treated as markup ([#1634](https://github.com/ThinkFlowLab/FlyBot/issues/1634)) — and the running tool in words (`bash` → running a command), follows the message's language, rotates its wording, and never repeats the chat's previous ack. The client draws it as one bot bubble (and also from a local pending queue/steer submission) so the chat is not silent while a blocking job wait holds the next step. Related but separate: [#1509](https://github.com/ThinkFlowLab/FlyBot/issues/1509) (Steer does not abort a tool wait). Host: `core/src/host/busy-ack.js`. Client: `core/src/client/busy-ack.js`. Tests: `core/test/busy-ack.test.js`, `core/test/busy-ack-client.test.js`.
 
 ## Steering interrupt: a wait over 60s yields to a human send (#1509)
 
diff --git a/patches/ds-bot/0005-social-seams.patch b/patches/ds-bot/0005-social-seams.patch
index 0538906c1..a4e11eba5 100644
--- a/patches/ds-bot/0005-social-seams.patch
+++ b/patches/ds-bot/0005-social-seams.patch
@@ -288,7 +288,7 @@ diff --git a/src/host/channel.js b/src/host/channel.js
  
  const invalid = message => Object.assign(new Error(message), { code: 'bot/invalid' })
  // Programming and file system errors are DS Bot's own faults, logged with their stack;
-@@ -21,32 +21,149 @@ export function install(rt) {
+@@ -21,32 +21,151 @@ export function install(rt) {
  
    // The DSH interface language of the last browser that asked for the team.
    let uiLocale
@@ -429,6 +429,8 @@ diff --git a/src/host/channel.js b/src/host/channel.js
 +        ...presented,
 +        log: undefined,
 +        parts,
++        // A member's busy ack, for the row that member's turn draws in the room flow (#1646).
++        busyAcks: rt.roomBusyAcksView?.(sessions) ?? {},
 +        pendingApprovals: pending,
 +        pendingCount: pending.length,
 +        ...(last ? { preview: previewWho } : {}),
diff --git a/patches/ds-bot/0008-client-bundle.patch b/patches/ds-bot/0008-client-bundle.patch
index cf545dfff..fe58d4536 100644
--- a/patches/ds-bot/0008-client-bundle.patch
+++ b/patches/ds-bot/0008-client-bundle.patch
@@ -5180,8 +5180,13 @@ diff --git a/client.js b/client.js
 -    ) : null,
 -    foot
 +    error ? (0, import_react8.createElement)("div", { className: "bt-flybot-approval-error", role: "alert" }, error) : null
++  );
++  return (0, import_react8.createElement)(
++    "div",
++    { className: "bt-held-actions", "data-flybot": "held-reply-actions" },
++    custom ? (0, import_react8.createElement)(boundary(), { id: custom.id, fallback: plain }, (0, import_react8.createElement)(custom.component, { held, decide, call: call3, actions })) : plain
    );
--}
+ }
 -function SettledQuestion({ question, answer }) {
 -  const options = optionsOf(question);
 -  const prompt = question?.question ?? "";
@@ -5199,12 +5204,6 @@ diff --git a/client.js b/client.js
 -    );
 -  }
 -  return (0, import_react4.createElement)(
-+  return (0, import_react8.createElement)(
-+    "div",
-+    { className: "bt-held-actions", "data-flybot": "held-reply-actions" },
-+    custom ? (0, import_react8.createElement)(boundary(), { id: custom.id, fallback: plain }, (0, import_react8.createElement)(custom.component, { held, decide, call: call3, actions })) : plain
-+  );
-+}
 +
 +// src/client/turn-reasoning.js
 +function turnReasoning(steps, current) {
@@ -5787,6 +5786,9 @@ diff --git a/client.js b/client.js
 -  const long = value.trim().length >= MIN_VALUE;
 -  const save = () => {
 -    if (long && !busy) void run(actions.secretSet({ requestId: request.id, value, scope }));
+-  };
+-  const allow = () => {
+-    if (!busy) void run(actions.secretAllow(request.id));
 +    try {
 +      const got = await call(`flybot/${plugin}/attachment`, { id: file.id, botId });
 +      const value = got?.value ?? got;
@@ -5801,10 +5803,43 @@ diff --git a/client.js b/client.js
 +      setBusy("");
 +    }
    };
--  const allow = () => {
--    if (!busy) void run(actions.secretAllow(request.id));
+-  const filling = request.kind === "fill" || replacing;
+-  const warn = insecure() ? (0, import_react5.createElement)("div", { className: "bt-secret-warn", role: "note" }, (0, import_react5.createElement)(WarnIcon), t("This page is not on HTTPS: the key crosses the network unencrypted.")) : null;
+-  return (0, import_react5.createElement)(
 +  return (0, import_react9.createElement)(
-+    "div",
+     "div",
+-    { className: "bt-q bt-secret", role: "group", "aria-describedby": noteId, "data-kind": request.kind },
+-    (0, import_react5.createElement)(SecretHead, {
+-      bot,
+-      title: request.kind === "allow" ? t("Let {bot} use {name}?", { bot: bot.name, name: request.name }) : t("{name} needs a key", { name: bot.name }),
+-      detail: request.purpose,
+-      name: request.name,
+-      onClose: busy ? void 0 : cancel
+-    }),
+-    request.kind === "allow" ? (0, import_react5.createElement)("div", { className: "bt-secret-saved" }, (0, import_react5.createElement)(KeyIcon), t("Saved for {scope}", { scope: scopeLabel(secret?.scope, roster) })) : null,
+-    filling ? (0, import_react5.createElement)(
+-      "div",
+-      { className: "bt-secret-body" },
+-      (0, import_react5.createElement)("label", { className: "bt-q-field bt-secret-field" }, (0, import_react5.createElement)(MaskedInput, { value, onChange: setValue, onEnter: save, label: t("Value of {name}", { name: request.name }), autoFocus: replacing })),
+-      request.kind === "fill" ? (0, import_react5.createElement)(ScopeSwitch, { value: scope, onChange: setScope, bot }) : null
+-    ) : null,
+-    (0, import_react5.createElement)(
+-      "div",
+-      { className: "bt-secret-note", id: noteId },
+-      t("{bot} never sees the value. It reaches {bot}'s shell as ", { bot: bot.name }),
+-      (0, import_react5.createElement)("code", null, `$DSH_SECRET_${request.name}`),
+-      ".",
+-      filling && value !== "" && !long ? t(" At least {count} characters.", { count: MIN_VALUE }) : ""
+-    ),
+-    warn,
+-    error ? (0, import_react5.createElement)("div", { className: "bt-secret-error", role: "alert" }, error) : null,
+-    (0, import_react5.createElement)(
+-      "div",
+-      { className: "bt-q-foot" },
+-      request.kind === "allow" && !replacing ? (0, import_react5.createElement)("button", { type: "button", className: "bt-q-btn", disabled: busy, onClick: () => setReplacing(true) }, t("Replace value")) : null,
+-      (0, import_react5.createElement)("button", { type: "button", className: "bt-q-btn", disabled: busy, onClick: cancel }, t("Cancel")),
+-      filling ? (0, import_react5.createElement)("button", { type: "button", className: "bt-q-submit", disabled: !long || busy, onClick: save }, busy ? t("Saving…") : t("Save")) : (0, import_react5.createElement)("button", { type: "button", className: "bt-q-submit", disabled: busy, onClick: allow }, busy ? t("Allowing…") : t("Allow"))
+-    )
 +    { className: "bt-file-chips" },
 +    files.map((file) => (0, import_react9.createElement)(
 +      "button",
@@ -5812,11 +5847,17 @@ diff --git a/client.js b/client.js
 +      `📎 ${file.name} · ${fileSize(file.size)}`
 +    )),
 +    error ? (0, import_react9.createElement)("span", { className: "bt-file-error", role: "alert" }, error) : null
-+  );
-+}
+   );
+ }
+-function SettledSecret({ bot, request, roster }) {
+-  const canceled = request.status === "canceled";
+-  const text = canceled ? t("{bot} asked for {name}", { bot: bot.name, name: request.name }) : request.status === "allowed" ? t("Allowed {bot} to use {name}", { bot: bot.name, name: request.name }) : t("Saved {name}", { name: request.name });
+-  return (0, import_react5.createElement)(
 +function GroupEvent({ prefix, room: room2, name, roster, actions }) {
 +  return (0, import_react9.createElement)(
-+    "div",
+     "div",
+-    { className: "bt-q bt-q-settled bt-secret bt-secret-done", role: "group", "aria-label": text, "data-status": request.status },
+-    (0, import_react5.createElement)(
 +    { className: "bt-event" },
 +    (0, import_react9.createElement)("span", null, prefix),
 +    room2 ? (0, import_react9.createElement)("button", { type: "button", onClick: () => actions.openSession(room2.id) }, (0, import_react9.createElement)(RoomAvatar, { room: room2, roster, size: 16 }), room2.name) : name ? (0, import_react9.createElement)("span", null, name) : null
@@ -5865,10 +5906,7 @@ diff --git a/client.js b/client.js
 +      busy.current = false;
 +      if (alive.current) setView((current) => ({ ...current, loading: false, failed: true }));
 +    });
-   };
--  const filling = request.kind === "fill" || replacing;
--  const warn = insecure() ? (0, import_react5.createElement)("div", { className: "bt-secret-warn", role: "note" }, (0, import_react5.createElement)(WarnIcon), t("This page is not on HTTPS: the key crosses the network unencrypted.")) : null;
--  return (0, import_react5.createElement)(
++  };
 +  (0, import_react9.useEffect)(() => {
 +    alive.current = true;
 +    load(void 0);
@@ -5898,43 +5936,23 @@ diff --git a/client.js b/client.js
 +    else rows.push(item.kind === "bot" ? { kind: "bot", texts: [item.text] } : item);
 +  }
 +  return (0, import_react9.createElement)(
-     "div",
--    { className: "bt-q bt-secret", role: "group", "aria-describedby": noteId, "data-kind": request.kind },
--    (0, import_react5.createElement)(SecretHead, {
--      bot,
--      title: request.kind === "allow" ? t("Let {bot} use {name}?", { bot: bot.name, name: request.name }) : t("{name} needs a key", { name: bot.name }),
--      detail: request.purpose,
--      name: request.name,
--      onClose: busy ? void 0 : cancel
--    }),
--    request.kind === "allow" ? (0, import_react5.createElement)("div", { className: "bt-secret-saved" }, (0, import_react5.createElement)(KeyIcon), t("Saved for {scope}", { scope: scopeLabel(secret?.scope, roster) })) : null,
--    filling ? (0, import_react5.createElement)(
--      "div",
--      { className: "bt-secret-body" },
--      (0, import_react5.createElement)("label", { className: "bt-q-field bt-secret-field" }, (0, import_react5.createElement)(MaskedInput, { value, onChange: setValue, onEnter: save, label: t("Value of {name}", { name: request.name }), autoFocus: replacing })),
--      request.kind === "fill" ? (0, import_react5.createElement)(ScopeSwitch, { value: scope, onChange: setScope, bot }) : null
--    ) : null,
--    (0, import_react5.createElement)(
++    "div",
 +    { className: "bt-earlier", role: "feed", "aria-label": t("Earlier messages"), "aria-busy": view.loading },
 +    (0, import_react9.createElement)(
        "div",
--      { className: "bt-secret-note", id: noteId },
--      t("{bot} never sees the value. It reaches {bot}'s shell as ", { bot: bot.name }),
--      (0, import_react5.createElement)("code", null, `$DSH_SECRET_${request.name}`),
--      ".",
--      filling && value !== "" && !long ? t(" At least {count} characters.", { count: MIN_VALUE }) : ""
+-      { className: "bt-q-head" },
+-      (0, import_react5.createElement)("span", { className: "bt-secret-who" }, (0, import_react5.createElement)(BotMark, { bot, size: 22 })),
+-      (0, import_react5.createElement)("div", { className: "bt-q-text" }, (0, import_react5.createElement)(
+-        "p",
+-        { className: "bt-q-title" },
+-        text,
+-        canceled ? null : (0, import_react5.createElement)("span", { className: "bt-secret-scope-tag" }, ` · ${scopeLabel(request.scope, roster)}`)
+-      )),
+-      canceled ? (0, import_react5.createElement)("span", { className: "bt-q-badge" }, t("Canceled")) : (0, import_react5.createElement)("span", { className: "bt-q-check bt-secret-check", title: t("Done") }, (0, import_react5.createElement)(CheckIcon))
+-    )
 +      { ref: top, className: "bt-earlier-top" },
 +      view.loading ? (0, import_react9.createElement)(Shimmer, null, t("Loading earlier messages…")) : view.failed ? (0, import_react9.createElement)("button", { type: "button", className: "bt-soft", onClick: () => load(view.cursor) }, t("Couldn’t load earlier messages · Retry")) : view.cursor ? (0, import_react9.createElement)("button", { type: "button", className: "bt-soft", onClick: () => load(view.cursor) }, t("Load earlier")) : null
-     ),
--    warn,
--    error ? (0, import_react5.createElement)("div", { className: "bt-secret-error", role: "alert" }, error) : null,
--    (0, import_react5.createElement)(
--      "div",
--      { className: "bt-q-foot" },
--      request.kind === "allow" && !replacing ? (0, import_react5.createElement)("button", { type: "button", className: "bt-q-btn", disabled: busy, onClick: () => setReplacing(true) }, t("Replace value")) : null,
--      (0, import_react5.createElement)("button", { type: "button", className: "bt-q-btn", disabled: busy, onClick: cancel }, t("Cancel")),
--      filling ? (0, import_react5.createElement)("button", { type: "button", className: "bt-q-submit", disabled: !long || busy, onClick: save }, busy ? t("Saving…") : t("Save")) : (0, import_react5.createElement)("button", { type: "button", className: "bt-q-submit", disabled: busy, onClick: allow }, busy ? t("Allowing…") : t("Allow"))
--    )
++    ),
 +    rows.map((row, index) => {
 +      const key = rows.length - index;
 +      switch (row.kind) {
@@ -5966,25 +5984,8 @@ diff --git a/client.js b/client.js
 +    (0, import_react9.createElement)(PartLine, { time: view.startedAt })
    );
  }
--function SettledSecret({ bot, request, roster }) {
--  const canceled = request.status === "canceled";
--  const text = canceled ? t("{bot} asked for {name}", { bot: bot.name, name: request.name }) : request.status === "allowed" ? t("Allowed {bot} to use {name}", { bot: bot.name, name: request.name }) : t("Saved {name}", { name: request.name });
--  return (0, import_react5.createElement)(
--    "div",
--    { className: "bt-q bt-q-settled bt-secret bt-secret-done", role: "group", "aria-label": text, "data-status": request.status },
--    (0, import_react5.createElement)(
--      "div",
--      { className: "bt-q-head" },
--      (0, import_react5.createElement)("span", { className: "bt-secret-who" }, (0, import_react5.createElement)(BotMark, { bot, size: 22 })),
--      (0, import_react5.createElement)("div", { className: "bt-q-text" }, (0, import_react5.createElement)(
--        "p",
--        { className: "bt-q-title" },
--        text,
--        canceled ? null : (0, import_react5.createElement)("span", { className: "bt-secret-scope-tag" }, ` · ${scopeLabel(request.scope, roster)}`)
--      )),
--      canceled ? (0, import_react5.createElement)("span", { className: "bt-q-badge" }, t("Canceled")) : (0, import_react5.createElement)("span", { className: "bt-q-check bt-secret-check", title: t("Done") }, (0, import_react5.createElement)(CheckIcon))
--    )
--  );
+-function RequestView({ bot, request, roster, actions }) {
+-  return request.status === "pending" ? (0, import_react5.createElement)(SecretCard, { key: `${request.id}:${request.kind}`, bot, request, roster, actions }) : (0, import_react5.createElement)(SettledSecret, { bot, request, roster });
 +function TriggerCell({ node, sessionId, useRoster, useSessions, useTurnClock, useUi, actions }) {
 +  const roster = useRoster((value) => value);
 +  const data = node.data;
@@ -6067,7 +6068,15 @@ diff --git a/client.js b/client.js
 +}
 +function NewDivider() {
 +  return (0, import_react9.createElement)("div", { className: "bt-new-sep", role: "separator", "aria-label": t("New messages") }, (0, import_react9.createElement)("span", null, t("New")));
-+}
+ }
+-function SecretToolCell({ sessionId, callId, name, done, content, roster, actions }) {
+-  const bot = roster.byId[sessionId];
+-  if (!bot) return null;
+-  const request = (roster.secretRequests?.[bot.id] ?? []).find((entry) => entry.callId === callId && (entry.sessionId ?? sessionId) === sessionId);
+-  if (request) return (0, import_react5.createElement)("div", { className: "bt-q-inline" }, (0, import_react5.createElement)(RequestView, { bot, request, roster, actions }));
+-  if (done && /already saved/.test(contentText(content))) {
+-    return (0, import_react5.createElement)("div", { className: "bt-event" }, (0, import_react5.createElement)("span", { className: "bt-secret-event" }, (0, import_react5.createElement)(KeyIcon), t("{bot} is using {name}", { bot: bot.name, name: name ?? t("a saved key") })));
+-  }
 +function TurnProcessCell({ node, sessionId, turnProcess, useRoster, useUi, useTurnClock, actions }) {
 +  const open = turnProcess === void 0 || !turnProcess.foldable || turnProcess.open;
 +  (0, import_react9.useEffect)(() => {
@@ -6085,19 +6094,20 @@ diff --git a/client.js b/client.js
 +    return !hidden && typeof visit?.seen === "number" && own?.first !== void 0 && own.first <= visit.seen && own.end !== void 0 && own.end > visit.seen && own.end <= visit.entered;
 +  });
 +  return fresh ? (0, import_react9.createElement)(NewDivider) : null;
- }
--function RequestView({ bot, request, roster, actions }) {
--  return request.status === "pending" ? (0, import_react5.createElement)(SecretCard, { key: `${request.id}:${request.kind}`, bot, request, roster, actions }) : (0, import_react5.createElement)(SettledSecret, { bot, request, roster });
++}
 +function Nothing() {
-+  return null;
+   return null;
  }
--function SecretToolCell({ sessionId, callId, name, done, content, roster, actions }) {
+-function SecretDock({ sessionId, useRoster, useCards, useSession, actions }) {
+-  const roster = useRoster((value) => value);
+-  const shown = useCards?.((state) => state[sessionId]) ?? NONE;
+-  const loading = useSession?.(historyLoading) === true;
 -  const bot = roster.byId[sessionId];
--  if (!bot) return null;
--  const request = (roster.secretRequests?.[bot.id] ?? []).find((entry) => entry.callId === callId && (entry.sessionId ?? sessionId) === sessionId);
--  if (request) return (0, import_react5.createElement)("div", { className: "bt-q-inline" }, (0, import_react5.createElement)(RequestView, { bot, request, roster, actions }));
--  if (done && /already saved/.test(contentText(content))) {
--    return (0, import_react5.createElement)("div", { className: "bt-event" }, (0, import_react5.createElement)("span", { className: "bt-secret-event" }, (0, import_react5.createElement)(KeyIcon), t("{bot} is using {name}", { bot: bot.name, name: name ?? t("a saved key") })));
+-  if (!bot || currentPart(bot) !== sessionId) return null;
+-  const drawn = (entry) => entry.callId && entry.sessionId === sessionId && (loading || shown[entry.callId] > 0);
+-  const waiting = (roster.secretRequests?.[bot.id] ?? []).filter((entry) => entry.status === "pending" && !drawn(entry));
+-  if (waiting.length === 0) return null;
+-  return (0, import_react5.createElement)("div", { className: "bt-q-dock bt-secret-dock" }, waiting.map((request) => (0, import_react5.createElement)(SecretCard, { key: `${request.id}:${request.kind}`, bot, request, roster, actions })));
 +var HIDDEN_REMOVED_TOOLS = /* @__PURE__ */ new Set(["ask_user_question"]);
 +var isConnectorTool = (name) => typeof name === "string" && /^mcp__(github|composio)__/.test(name);
 +var SILENT_REGISTRATION_TOOLS = /* @__PURE__ */ new Set([
@@ -6146,32 +6156,10 @@ diff --git a/client.js b/client.js
 +    if (isHiddenNotice(block)) continue;
 +    if (block?.type === "tool-removal" && block.toolName) parts.push(`Tool removed: ${block.toolName}`);
 +    else if (block?.type === "tool-addition" && block.toolName) parts.push(`Tool added: ${block.toolName}`);
-   }
--  return null;
++  }
 +  if (parts.length === 0) return null;
 +  return (0, import_react9.createElement)("div", { className: "bt-event" }, parts.join(" · "));
  }
--function SecretDock({ sessionId, useRoster, useCards, useSession, actions }) {
--  const roster = useRoster((value) => value);
--  const shown = useCards?.((state) => state[sessionId]) ?? NONE;
--  const loading = useSession?.(historyLoading) === true;
--  const bot = roster.byId[sessionId];
--  if (!bot || currentPart(bot) !== sessionId) return null;
--  const drawn = (entry) => entry.callId && entry.sessionId === sessionId && (loading || shown[entry.callId] > 0);
--  const waiting = (roster.secretRequests?.[bot.id] ?? []).filter((entry) => entry.status === "pending" && !drawn(entry));
--  if (waiting.length === 0) return null;
--  return (0, import_react5.createElement)("div", { className: "bt-q-dock bt-secret-dock" }, waiting.map((request) => (0, import_react5.createElement)(SecretCard, { key: `${request.id}:${request.kind}`, bot, request, roster, actions })));
-+var SEPARATOR_GAP_MS = 30 * 60 * 1e3;
-+function clockLabel(time, now = Date.now()) {
-+  const date = new Date(time);
-+  const midnight = (value) => new Date(value.getFullYear(), value.getMonth(), value.getDate()).getTime();
-+  const days = Math.round((midnight(new Date(now)) - midnight(date)) / 864e5);
-+  const clock4 = date.toLocaleTimeString(dateLocale(), { hour: "numeric", minute: "2-digit" });
-+  if (days === 0) return t("Today {time}", { time: clock4 });
-+  if (days === 1) return t("Yesterday {time}", { time: clock4 });
-+  const sameYear = date.getFullYear() === new Date(now).getFullYear();
-+  return `${date.toLocaleDateString(dateLocale(), { weekday: "short", month: "short", day: "numeric", ...sameYear ? {} : { year: "numeric" } })} ${clock4}`;
- }
 -function ScopeEditor({ secret, roster, onSave }) {
 -  const [mode, setMode] = (0, import_react5.useState)(secret.scope === "all" ? "all" : "some");
 -  const [picked, setPicked] = (0, import_react5.useState)(secret.scope === "all" ? [] : secret.scope);
@@ -6204,13 +6192,16 @@ diff --git a/client.js b/client.js
 -      (0, import_react5.createElement)("button", { type: "button", className: "bt-soft bt-soft-sm", disabled: same, onClick: () => onSave(mode === "all" ? "all" : picked) }, t("Save access"))
 -    )
 -  );
-+function nextTurnStart(turns, turn) {
-+  let next;
-+  for (const key in turns) {
-+    const candidate = Number(key);
-+    if (candidate > turn && turns[key].first !== void 0 && (next === void 0 || candidate < next)) next = candidate;
-+  }
-+  return next === void 0 ? void 0 : turns[next].first;
++var SEPARATOR_GAP_MS = 30 * 60 * 1e3;
++function clockLabel(time, now = Date.now()) {
++  const date = new Date(time);
++  const midnight = (value) => new Date(value.getFullYear(), value.getMonth(), value.getDate()).getTime();
++  const days = Math.round((midnight(new Date(now)) - midnight(date)) / 864e5);
++  const clock4 = date.toLocaleTimeString(dateLocale(), { hour: "numeric", minute: "2-digit" });
++  if (days === 0) return t("Today {time}", { time: clock4 });
++  if (days === 1) return t("Yesterday {time}", { time: clock4 });
++  const sameYear = date.getFullYear() === new Date(now).getFullYear();
++  return `${date.toLocaleDateString(dateLocale(), { weekday: "short", month: "short", day: "numeric", ...sameYear ? {} : { year: "numeric" } })} ${clock4}`;
  }
 -function ValueEditor({ secret, onSave }) {
 -  const [value, setValue] = (0, import_react5.useState)("");
@@ -6241,14 +6232,13 @@ diff --git a/client.js b/client.js
 -    ),
 -    value !== "" && !long ? (0, import_react5.createElement)("div", { className: "bt-set-hint" }, t("At least {count} characters.", { count: MIN_VALUE })) : replaced ? (0, import_react5.createElement)("div", { className: "bt-set-hint bt-secret-ok", role: "status" }, (0, import_react5.createElement)(CheckIcon), t("Replaced. Bots get the new value from their next command.")) : null
 -  );
-+function openingTurn(turns, firstTurns, hiddenTurns) {
-+  if (!turns || !firstTurns) return null;
-+  const start = nextTurnStart(turns, -Infinity);
-+  if (start === void 0) return null;
-+  const turn = Number(Object.keys(turns).filter((key) => turns[key].first === start)[0]);
-+  const listed = firstTurns.split(",").map(Number);
-+  const earlier = listed.filter((entry) => entry < turn);
-+  return listed.includes(turn) && earlier.every((entry) => hiddenTurns?.includes(entry)) ? { turn, start } : null;
++function nextTurnStart(turns, turn) {
++  let next;
++  for (const key in turns) {
++    const candidate = Number(key);
++    if (candidate > turn && turns[key].first !== void 0 && (next === void 0 || candidate < next)) next = candidate;
++  }
++  return next === void 0 ? void 0 : turns[next].first;
  }
 -function SecretRow({ secret, roster, actions, run, open, onToggle }) {
 -  const [confirm, setConfirm] = (0, import_react5.useState)(false);
@@ -6292,14 +6282,14 @@ diff --git a/client.js b/client.js
 -      )
 -    ) : null
 -  );
-+var unseenSince = (visit, time) => typeof visit?.seen === "number" && time > visit.seen && time <= visit.entered;
-+function movedOnSince(visit, turns, hiddenTurns) {
-+  if (typeof visit?.entered !== "number") return false;
-+  for (const key in turns ?? {}) {
-+    if (hiddenTurns?.includes(Number(key))) continue;
-+    if (turns[key].first !== void 0 && turns[key].first > visit.entered) return true;
-+  }
-+  return false;
++function openingTurn(turns, firstTurns, hiddenTurns) {
++  if (!turns || !firstTurns) return null;
++  const start = nextTurnStart(turns, -Infinity);
++  if (start === void 0) return null;
++  const turn = Number(Object.keys(turns).filter((key) => turns[key].first === start)[0]);
++  const listed = firstTurns.split(",").map(Number);
++  const earlier = listed.filter((entry) => entry < turn);
++  return listed.includes(turn) && earlier.every((entry) => hiddenTurns?.includes(entry)) ? { turn, start } : null;
  }
 -function AddSecret({ actions, run, onDone }) {
 -  const [name, setName] = (0, import_react5.useState)("");
@@ -6328,6 +6318,15 @@ diff --git a/client.js b/client.js
 -      (0, import_react5.createElement)("button", { type: "button", className: "bt-soft bt-soft-sm", onClick: onDone }, t("Cancel")),
 -      (0, import_react5.createElement)("button", { type: "button", className: "bt-soft bt-soft-sm", disabled: !ready, onClick: save }, t("Save key"))
 -    )
++var unseenSince = (visit, time) => typeof visit?.seen === "number" && time > visit.seen && time <= visit.entered;
++function movedOnSince(visit, turns, hiddenTurns) {
++  if (typeof visit?.entered !== "number") return false;
++  for (const key in turns ?? {}) {
++    if (hiddenTurns?.includes(Number(key))) continue;
++    if (turns[key].first !== void 0 && turns[key].first > visit.entered) return true;
++  }
++  return false;
++}
 +var settledVisit = (visit) => typeof visit?.seen === "number" && visit.seen < visit.entered ? { ...visit, seen: visit.entered } : visit;
 +function TurnTailCell({ turn: location2, sessionId, useTurnClock, useUi, actions }) {
 +  const turn = location2.turn;
@@ -10306,7 +10305,7 @@ diff --git a/client.js b/client.js
  @keyframes bt-update-pop{from{opacity:0;transform:scale(.96);filter:blur(4px)}}
  .bt-update-title{font-size:14px;line-height:20px;font-weight:600}
  .bt-update-text{margin-top:2px;font-size:12.5px;line-height:18px;color:var(--bt-ink-2)}
-@@ -5491,18 +5491,128 @@ var SIDEBAR_CSS = `
+@@ -5491,18 +5491,140 @@ var SIDEBAR_CSS = `
  .bt-agent-sub[data-open] .bt-agent-sub-row{animation:bt-agent-row-in .24s ease both;animation-delay:calc(var(--i, 0)*30ms)}
  @keyframes bt-agent-row-in{from{opacity:0;filter:blur(4px)}to{opacity:1;filter:blur(0)}}
  @media (prefers-reduced-motion:reduce){.bt-agent-sub{transition:none}.bt-agent-sub .bt-agent-sub-row{animation:none}}
@@ -10339,6 +10338,16 @@ diff --git a/client.js b/client.js
 +  if (streamingText) return false;
 +  return busyAckText(hostAck) !== "" || pendingBusy === true;
 +}
++function roomBusyAck(room2) {
++  const entries2 = Object.entries(room2?.busyAcks ?? {}).filter(([, ack2]) => ack2 !== void 0 && ack2 !== null);
++  if (entries2.length === 0) return null;
++  const [botId, ack] = entries2.sort((a, b) => (b[1].at ?? 0) - (a[1].at ?? 0))[0];
++  return { botId, text: busyAckText(ack), at: ack.at ?? 0 };
++}
++function roomBusyAckVisible({ ack, pendingBusy }) {
++  if (ack === null || ack === void 0) return false;
++  return ack.text !== "" || pendingBusy === true;
++}
 +
 +// src/client/busy-ack.js
 +var import_react17 = require("react");
@@ -10371,15 +10380,17 @@ diff --git a/client.js b/client.js
 +}
 +function BusyAckBubble({ sessionId, useRoster, useBusyAcks, useSessionStatus, useSession, useLive }) {
 +  const roster = useRoster((value) => value);
++  const room2 = roster.roomsById?.[sessionId];
++  const memberAck = room2 ? roomBusyAck(room2) : null;
 +  const hostAck = useBusyAcks((map) => map?.[sessionId] ?? null);
 +  const running = useSessionStatus((map) => map.get(sessionId)?.running === true);
 +  const pendingBusy = useSession((snapshot) => pendingBusyPlacement(snapshot?.pendingSubmissions));
 +  const streamingText = useLive((state) => Object.values(state[sessionId] ?? {}).some((entry) => entry?.text));
-+  const visible = running && busyAckVisible({ hostAck, pendingBusy, streamingText });
-+  const bot = roster.byId[sessionId];
++  const visible = room2 ? roomBusyAckVisible({ ack: memberAck, pendingBusy }) : running && busyAckVisible({ hostAck, pendingBusy, streamingText });
++  const bot = room2 ? roster.byId[memberAck?.botId] : roster.byId[sessionId];
 +  const host = useRunningHost2(visible);
 +  const shown = (0, import_react17.useRef)(null);
-+  if (visible) shown.current = { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() };
++  if (visible) shown.current = room2 ? { text: memberAck?.text ?? "", at: memberAck?.at ?? Date.now() } : { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() };
 +  const text = shown.current?.text ?? "";
 +  if (!visible || !host || !shown.current || !bot) return null;
 +  return (0, import_react_dom4.createPortal)((0, import_react17.createElement)(
diff --git a/patches/ds-bot/files/src/client/busy-ack-logic.js b/patches/ds-bot/files/src/client/busy-ack-logic.js
index 4a665bcd8..ce89dc862 100644
--- a/patches/ds-bot/files/src/client/busy-ack-logic.js
+++ b/patches/ds-bot/files/src/client/busy-ack-logic.js
@@ -19,3 +19,21 @@ export function busyAckVisible({ hostAck, pendingBusy, streamingText }) {
   if (streamingText) return false
   return busyAckText(hostAck) !== '' || pendingBusy === true
 }
+
+// The ack a room flow draws on its member's row (#1646). The host publishes `room.busyAcks`
+// keyed by the member while that member's turn runs in the room; an entry whose text is still
+// empty means the host's line is not composed yet, which the client draws the way #1656 draws
+// a pending own-chat ack: the mark and the blinking indicator, no fixed sentence.
+export function roomBusyAck(room) {
+  const entries = Object.entries(room?.busyAcks ?? {}).filter(([, ack]) => ack !== undefined && ack !== null)
+  if (entries.length === 0) return null
+  const [botId, ack] = entries.sort((a, b) => (b[1].at ?? 0) - (a[1].at ?? 0))[0]
+  return { botId, text: busyAckText(ack), at: ack.at ?? 0 }
+}
+
+// A room's ack is drawn while that member's turn runs: the host's line as text, or the blinking
+// indicator alone while the person's line is still queued in the room and the line is not here.
+export function roomBusyAckVisible({ ack, pendingBusy }) {
+  if (ack === null || ack === undefined) return false
+  return ack.text !== '' || pendingBusy === true
+}
diff --git a/patches/ds-bot/files/src/client/busy-ack.js b/patches/ds-bot/files/src/client/busy-ack.js
index d88908352..ad309e9de 100644
--- a/patches/ds-bot/files/src/client/busy-ack.js
+++ b/patches/ds-bot/files/src/client/busy-ack.js
@@ -2,9 +2,11 @@ import { createElement as h, useEffect, useRef, useState } from 'react'
 import { createPortal } from 'react-dom'
 import { BotMark } from './mark.js'
 import { RUNNING_HOST } from './activity-row.js'
-import { busyAckText, busyAckVisible, pendingBusyPlacement } from './busy-ack-logic.js'
+import { busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible } from './busy-ack-logic.js'
 
-export { busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement } from './busy-ack-logic.js'
+export {
+  busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible,
+} from './busy-ack-logic.js'
 
 // Spoken busy-ack (#1584): when a human send is accepted while the Bot is running
 // (host live busyAcks, or a local pending queue/steer submission), show one short
@@ -32,15 +34,23 @@ function useRunningHost(active) {
 
 export function BusyAckBubble({ sessionId, useRoster, useBusyAcks, useSessionStatus, useSession, useLive }) {
   const roster = useRoster(value => value)
+  const room = roster.roomsById?.[sessionId]
+  // A group draws one member's ack on the row that member's turn runs in (#1646); its
+  // Session is not the conversation being shown, so `busyAcks[sessionId]` never has it.
+  const memberAck = room ? roomBusyAck(room) : null
   const hostAck = useBusyAcks(map => map?.[sessionId] ?? null)
   const running = useSessionStatus(map => map.get(sessionId)?.running === true)
   const pendingBusy = useSession(snapshot => pendingBusyPlacement(snapshot?.pendingSubmissions))
   const streamingText = useLive(state => Object.values(state[sessionId] ?? {}).some(entry => entry?.text))
-  const visible = running && busyAckVisible({ hostAck, pendingBusy, streamingText })
-  const bot = roster.byId[sessionId]
+  const visible = room
+    ? roomBusyAckVisible({ ack: memberAck, pendingBusy })
+    : running && busyAckVisible({ hostAck, pendingBusy, streamingText })
+  const bot = room ? roster.byId[memberAck?.botId] : roster.byId[sessionId]
   const host = useRunningHost(visible)
   const shown = useRef(null)
-  if (visible) shown.current = { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() }
+  if (visible) shown.current = room
+    ? { text: memberAck?.text ?? '', at: memberAck?.at ?? Date.now() }
+    : { text: busyAckText(hostAck), at: hostAck?.at ?? Date.now() }
   const text = shown.current?.text ?? ''
   if (!visible || !host || !shown.current || !bot) return null
   return createPortal(h('div', {
diff --git a/patches/ds-bot/files/src/host/busy-ack.js b/patches/ds-bot/files/src/host/busy-ack.js
index 2cd736d31..f15e603a4 100644
--- a/patches/ds-bot/files/src/host/busy-ack.js
+++ b/patches/ds-bot/files/src/host/busy-ack.js
@@ -129,6 +129,19 @@ export function shouldNoteBusyAck({ sourceKind, turnRunning, ownChat }) {
   return sourceKind === 'user' && turnRunning === true && ownChat === true
 }
 
+// A person's line reaching a member's group Session (#1646). A round relays it as
+// `role: 'room'` with no Bot sender: a Bot's own call carries `senderSessionId`, an
+// @-mention by another Bot carries `askedBy`, and a friend's Bot carries `remote`.
+export function isHumanRoomLine(source) {
+  return source?.role === 'room'
+    && source.senderSessionId === undefined
+    && source.askedBy === undefined
+    && source.remote === undefined
+}
+
+// The relay prefix delivery.js puts on the line; the ack quotes the person's text, not it.
+const relayHeader = /^\[[^\]\n]*\]\r?\n/
+
 const textOf = (content) => {
   if (typeof content === 'string') return content
   if (!Array.isArray(content)) return ''
@@ -145,6 +158,9 @@ export function install(rt) {
 
   const turnRunning = sessionId => rt.live?.get(sessionId)?.turn !== undefined
   const ownChat = sessionId => rt.chatOwners?.has(sessionId) === true
+  const groupSession = sessionId => rt.groupOwners?.has(sessionId) === true
+  /** A person's line into this member's running group Session (#1646), once only. */
+  const roomLine = (sessionId, source) => groupSession(sessionId) && isHumanRoomLine(source)
 
   const note = (sessionId, message) => {
     const now = Date.now()
@@ -173,12 +189,12 @@ export function install(rt) {
     const id = session?.id
     if (id === undefined || event?.type === undefined) return
     if (event.type === 'user/message') {
-      if (!shouldNoteBusyAck({
-        sourceKind: event.data?.source?.kind,
-        turnRunning: turnRunning(id),
-        ownChat: ownChat(id),
-      })) return
-      note(id, textOf(event.data?.content ?? event.data?.message?.content))
+      const source = event.data?.source
+      const room = roomLine(id, source)
+      const own = shouldNoteBusyAck({ sourceKind: source?.kind, turnRunning: turnRunning(id), ownChat: ownChat(id) })
+      if (!own && !(room && turnRunning(id))) return
+      const text = textOf(event.data?.content ?? event.data?.message?.content)
+      note(id, room ? text.replace(relayHeader, '') : text)
       return
     }
     if (event.type === 'assistant/message') {
@@ -196,6 +212,15 @@ export function install(rt) {
 
   Object.assign(rt, {
     busyAcksView: () => Object.fromEntries([...acks].map(([id, ack]) => [id, { text: ack.text, at: ack.at }])),
+    // A room draws the ack on its running member's row (#1646), so its flow is keyed by
+    // member, not by the Session a person cannot see. A member whose turn runs before its
+    // line is composed is published with an empty text: the client draws the same blinking
+    // indicator an own-chat pending ack draws (#1656), never a fixed sentence.
+    roomBusyAcksView: sessions => Object.fromEntries(Object.entries(sessions ?? {}).flatMap(([botId, sessionId]) => {
+      if (!turnRunning(sessionId)) return []
+      const ack = acks.get(sessionId)
+      return [[botId, ack === undefined ? { text: '', at: 0 } : { text: ack.text, at: ack.at }]]
+    })),
     noteBusyAck: note,
     clearBusyAck: clear,
   })
diff --git a/patches/ds-bot/files/test/busy-ack-client.test.js b/patches/ds-bot/files/test/busy-ack-client.test.js
index 71f9a6d3c..b7e8603b3 100644
--- a/patches/ds-bot/files/test/busy-ack-client.test.js
+++ b/patches/ds-bot/files/test/busy-ack-client.test.js
@@ -3,7 +3,9 @@ import { readFileSync } from 'node:fs'
 import { test } from 'node:test'
 import * as logic from '../src/client/busy-ack-logic.js'
 
-const { busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement } = logic
+const {
+  busyAckPending, busyAckText, busyAckVisible, pendingBusyPlacement, roomBusyAck, roomBusyAckVisible,
+} = logic
 
 test('pendingBusyPlacement is true for queued or steering submissions', () => {
   assert.equal(pendingBusyPlacement([]), false)
@@ -43,3 +45,27 @@ test('#1656: the canned sentence is not shipped anywhere in the client', () => {
   assert.match(bubble, /'aria-busy': text \? undefined : 'true'/)
   assert.match(bubble, /@keyframes bt-busy-blink/)
 })
+
+test('a room ack is the running member\'s, keyed by the member the host noted (#1646)', () => {
+  assert.equal(roomBusyAck(undefined), null)
+  assert.equal(roomBusyAck({}), null)
+  assert.equal(roomBusyAck({ busyAcks: {} }), null)
+  assert.deepEqual(roomBusyAck({ busyAcks: { b: { text: '收到', at: 7 } } }), { botId: 'b', text: '收到', at: 7 })
+  // The host publishes the member as soon as its turn runs; empty text means the ack line is
+  // still being composed, and the client draws the pending dots for it (#1656, #1646).
+  assert.deepEqual(roomBusyAck({ busyAcks: { b: { text: '', at: 1 } } }), { botId: 'b', text: '', at: 1 })
+  assert.equal(roomBusyAck({ busyAcks: { b: { text: '   ', at: 1 } } }).text, '')
+  // Only the speaking member has one; the newest wins if two ever land together.
+  assert.deepEqual(
+    roomBusyAck({ busyAcks: { a: { text: 'older', at: 5 }, b: { text: 'newer', at: 9 } } }),
+    { botId: 'b', text: 'newer', at: 9 },
+  )
+})
+
+test('a room ack shows its line, or the blinking dots while the person\'s line is still queued (#1646)', () => {
+  assert.equal(roomBusyAckVisible({ ack: null, pendingBusy: true }), false)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '', at: 1 }, pendingBusy: false }), false)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '', at: 1 }, pendingBusy: true }), true)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '收到', at: 1 }, pendingBusy: false }), true)
+  assert.equal(roomBusyAckVisible({ ack: { botId: 'b', text: '收到', at: 1 }, pendingBusy: true }), true)
+})
diff --git a/patches/ds-bot/files/test/busy-ack.test.js b/patches/ds-bot/files/test/busy-ack.test.js
index 9700f81d4..677a1f1f6 100644
--- a/patches/ds-bot/files/test/busy-ack.test.js
+++ b/patches/ds-bot/files/test/busy-ack.test.js
@@ -1,8 +1,12 @@
 import assert from 'node:assert/strict'
+import { mkdtempSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
 import { test } from 'node:test'
 import {
-  ackLanguage, composeBusyAck, doingOf, shouldNoteBusyAck, topicOf,
+  ackLanguage, composeBusyAck, doingOf, install as installBusyAck, shouldNoteBusyAck, topicOf,
 } from '../src/host/busy-ack.js'
+import { install as installStore } from '../src/host/store.js'
 
 // The pre-#1629 canned lines; an ack must never be either verbatim.
 const OLD_ZH = '收到，我先记着，手头忙完再详细回你。'
@@ -151,3 +155,137 @@ test('a {t} typed in the message is quoted back verbatim, with and without a run
     }
   }
 })
+
+// --- The room side (#1646) -------------------------------------------------
+// A group's member speaks from a hidden Session (`room.sessions[botId]`), and the person's line
+// reaches it as a relayed `role: 'room'` message, not as `source.kind === 'user'`. These tests
+// run the real store beside the real busy-ack install, so `chatOwners` and `groupOwners` are the
+// host's own indexes; only `live` is seeded, as turns.js would have recorded a running turn.
+const roomHost = async (t) => {
+  const dir = mkdtempSync(join(tmpdir(), 'ds-bot-busy-ack-room-'))
+  const statePath = join(dir, 'state.json')
+  writeFileSync(statePath, JSON.stringify({
+    version: 2,
+    mainBotIds: ['a'],
+    members: { 'owner-1': { id: 'owner-1', createdAt: 1, designatedChiefId: 'a' } },
+    bots: {
+      a: { id: 'a', name: 'Chief', sessionId: 'a', ownerId: 'owner-1', createdAt: 1 },
+      b: { id: 'b', name: 'Writer', sessionId: 'b', ownerId: 'owner-1', createdAt: 2 },
+    },
+    rooms: {
+      r1: {
+        id: 'r1', name: 'Ops', members: ['a', 'b'], mode: 'admin', admin: 'b', named: true,
+        sessions: { b: 'gb' }, log: [], seq: 0, seen: {},
+      },
+    },
+    agents: {}, exchanges: [], exchangeTurns: {}, questions: {}, prefs: {}, revision: 0,
+  }))
+  const disposers = []
+  const listeners = new Map()
+  const ctx = {
+    logger: { warn() {}, info() {} },
+    effect(execute) { const dispose = execute(); if (typeof dispose === 'function') disposers.push(dispose) },
+    on(name, fn) { const list = listeners.get(name) ?? listeners.set(name, []).get(name); list.push(fn); return () => {} },
+  }
+  const rt = {
+    ctx, home: dir, statePath,
+    autoRoomName: () => 'Room', retitleRoom: async () => {}, dropGroupSession: () => {}, warn: () => {},
+  }
+  installStore(rt)
+  await rt.load()
+  rt.live = new Map()
+  installBusyAck(rt)
+  t.after(() => {
+    for (const dispose of disposers.splice(0)) dispose()
+    rmSync(dir, { recursive: true, force: true, maxRetries: 5 })
+  })
+  const fire = (name, ...args) => { for (const fn of listeners.get(name) ?? []) fn(...args) }
+  const emit = (id, type, data) => fire('session/event', { id }, { type, seq: 1, data })
+  return { rt, emit, fire, chatOwners: rt.chatOwners, groupOwners: rt.groupOwners }
+}
+
+// The relay a person's line takes into a member's group Session (delivery.js + groups.js).
+const roomSay = text => ({
+  type: 'user/message',
+  data: {
+    source: { kind: 'bot', form: 'relay', role: 'room', roomId: 'r1', exchangeId: 'x1', senderName: 'You', hop: 0 },
+    content: [{ type: 'text', text: `[Group chat "Ops" · new message from the user]\n${text}` }],
+  },
+})
+
+test('the indexes the room case leans on are the store\'s own (#1646)', async (t) => {
+  const host = await roomHost(t)
+  assert.equal(host.chatOwners.get('b'), 'b')
+  assert.equal(host.chatOwners.has('gb'), false)
+  assert.deepEqual(host.groupOwners.get('gb'), { botId: 'b', roomId: 'r1' })
+})
+
+test('a room line steered into a running member\'s Session notes one ack for that Session (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('gb', { turn: 1, tool: 'bash' })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  host.emit('gb', 'user/message', roomSay('帮我把周报再改一下').data)
+  const acks = host.rt.busyAcksView()
+  assert.deepEqual(Object.keys(acks), ['gb'])
+  assert.match(acks.gb.text, /周报/)
+  assert.match(acks.gb.text, /跑命令/)
+  assert.doesNotMatch(acks.gb.text, /Group chat/)
+  // Coalesced: a second line inside the window keeps the one ack.
+  const at = acks.gb.at
+  host.emit('gb', 'user/message', roomSay('again').data)
+  assert.deepEqual(Object.keys(host.rt.busyAcksView()), ['gb'])
+  assert.equal(host.rt.busyAcksView().gb.text, acks.gb.text)
+  assert.ok(host.rt.busyAcksView().gb.at >= at)
+  // No ack survives the turn.
+  host.emit('gb', 'turn/end', { turn: 1, reason: { kind: 'completed' } })
+  assert.deepEqual(host.rt.busyAcksView(), {})
+  host.rt.live.set('gb', { turn: 2 })
+  host.emit('gb', 'user/message', roomSay('还在吗').data)
+  assert.ok(host.rt.busyAcksView().gb)
+  host.fire('agent/status', { agent: { session: { id: 'gb' } }, status: 'idle' })
+  assert.deepEqual(host.rt.busyAcksView(), {})
+})
+
+test('a room line to an idle member, and a line another Bot relayed, note nothing (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.emit('gb', 'user/message', roomSay('没有 turn').data)
+  assert.deepEqual(host.rt.busyAcksView(), {})
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  const fromBot = roomSay('another Bot called you')
+  fromBot.data.source.senderSessionId = 'a'
+  fromBot.data.source.askedBy = 'a'
+  host.emit('gb', 'user/message', fromBot.data)
+  assert.deepEqual(host.rt.busyAcksView(), {})
+})
+
+test('the room view names a running member before its line lands, then carries the line (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  // The member's turn is already running while the person's line is still being composed:
+  // an empty text, which the client draws as the pending blinking indicator, no sentence.
+  assert.deepEqual(host.rt.roomBusyAcksView({ b: 'gb' }), { b: { text: '', at: 0 } })
+  host.emit('gb', 'user/message', roomSay('帮我把周报再改一下').data)
+  assert.match(host.rt.roomBusyAcksView({ b: 'gb' }).b.text, /周报/)
+  assert.doesNotMatch(host.rt.roomBusyAcksView({ b: 'gb' }).b.text, /Group chat/)
+  // No running turn, no entry; an empty member map stays empty.
+  host.rt.live.delete('gb')
+  assert.deepEqual(host.rt.roomBusyAcksView({ b: 'gb' }), {})
+  assert.deepEqual(host.rt.roomBusyAcksView({}), {})
+})
+
+test('the own-chat ack is unchanged beside the room path (#1646)', async (t) => {
+  const host = await roomHost(t)
+  host.rt.live.set('b', { turn: 1, tool: 'bash' })
+  host.emit('b', 'turn/start', { turn: 1 })
+  host.emit('b', 'user/message', say('check the logs').data)
+  const acks = host.rt.busyAcksView()
+  assert.deepEqual(Object.keys(acks), ['b'])
+  assert.match(acks.b.text, /check the logs/)
+  // The same Session id space: a room line in the member's group Session is its own key.
+  host.rt.live.set('gb', { turn: 1 })
+  host.emit('gb', 'turn/start', { turn: 1 })
+  host.emit('gb', 'user/message', roomSay('帮我看日志').data)
+  assert.deepEqual(Object.keys(host.rt.busyAcksView()).sort(), ['b', 'gb'])
+})