fix(notifications): notification replies re-check encryption at send time and use the right account (#299)

The service worker posts inline notification replies in the clear (it
cannot encrypt). The Reply action was only withheld for rooms that were
encrypted when the notification was shown, so a reply typed hours later
into a room that has since turned on encryption went out unencrypted.
It also posted with the newest session the worker knew, not the
notification's account.

The worker now GETs the room's m.room.encryption state first and only
sends on a definite 404; notifications carry the user id and the worker
uses that account's session (or refuses). "Reply not sent" says why.

Fixes #299

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

package-lock.json

@@ -81,7 +81,7 @@
       },
       "devDependencies": {
         "@axe-core/playwright": "4.13.0",
-        "@lotusguild/element-call-embedded": "0.25.0-lotus.22",
+        "@lotusguild/element-call-embedded": "0.25.0-lotus.23",
         "@playwright/test": "1.63.0",
         "@rollup/plugin-inject": "5.0.5",
         "@rollup/plugin-wasm": "6.2.2",
@@ -2695,9 +2695,9 @@
       "integrity": "sha512-dfLbk+PwWvFzSxwk3n5ySL0hfBog779o8h68wK/7/APo/7cgyWp5jcXockbxdk5kFRkbeXWm4Fbi9FrdN381sA=="
     },
     "node_modules/@lotusguild/element-call-embedded": {
-      "version": "0.25.0-lotus.22",
-      "resolved": "https://code.lotusguild.org/api/packages/LotusGuild/npm/%40lotusguild%2Felement-call-embedded/-/0.25.0-lotus.22/element-call-embedded-0.25.0-lotus.22.tgz",
-      "integrity": "sha512-AimDKZA4xUKEEyl2XUFUSUDl03tBKFv88T/3igKyH2VqNSPMGnqcQJC5HXIkHLTWrOmg8kLcJ//FFbqlUZiLcA==",
+      "version": "0.25.0-lotus.23",
+      "resolved": "https://code.lotusguild.org/api/packages/LotusGuild/npm/%40lotusguild%2Felement-call-embedded/-/0.25.0-lotus.23/element-call-embedded-0.25.0-lotus.23.tgz",
+      "integrity": "sha512-vRmcWeJcU0Accyl2x3mqNEzrIe8djE5BekyYbYOSCsMflC98rZgD1mO7KOe7bA1cX7gparRf6sAt1fotHoU+bA==",
       "dev": true
     },
     "node_modules/@matrix-org/matrix-sdk-crypto-wasm": {

package.json

@@ -108,7 +108,7 @@
   },
   "devDependencies": {
     "@axe-core/playwright": "4.13.0",
-    "@lotusguild/element-call-embedded": "0.25.0-lotus.22",
+    "@lotusguild/element-call-embedded": "0.25.0-lotus.23",
     "@playwright/test": "1.63.0",
     "@rollup/plugin-inject": "5.0.5",
     "@rollup/plugin-wasm": "6.2.2",

src/app/components/CallEmbedProvider.tsx

@@ -111,8 +111,6 @@ type IncomingCallInfo = {
   intent?: string;
   notificationType: RTCNotificationType;
   refEventId: string;
-  /** [Gitea #313] The rtc.notification event itself: what a decline must reference (MSC4310). */
-  notificationEventId?: string;
 };
 type IncomingCallProps = {
   dm: boolean;
@@ -285,9 +283,7 @@ function IncomingCall({ dm, info, onIgnore, onAnswer, onReject }: IncomingCallPr
                   fill="Soft"
                   size="400"
                   radii="400"
-                  onClick={() =>
-                    dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-                  }
+                  onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
                   before={<Icon size="200" src={Icons.Cross} filled />}
                 >
                   <Text as="span" size="B400">
@@ -459,9 +455,7 @@ function IncomingCallBanner({ dm, info, onIgnore, onAnswer, onReject }: Incoming
           size="300"
           radii="300"
           outlined
-          onClick={() =>
-            dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-          }
+          onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
           before={<Icon size="100" src={Icons.Cross} filled />}
         >
           <Text as="span" size="B300">
@@ -602,7 +596,6 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
             : undefined,
         notificationType,
         refEventId,
-        notificationEventId: event.getId(),
       };
 
       // [Gitea #312] Don't ring for a call that is already over or handled: after
@@ -611,10 +604,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       // stale RTC session). The caller's membership can arrive just after the
       // ring, so an absent one gets a short grace period before giving up.
       const myUserId = mx.getSafeUserId();
-      if (
-        declinedRing(room, [refEventId, event.getId()], myUserId) ||
-        hasActiveCallMembership(room, myUserId)
-      ) {
+      if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
         return;
       }
       if (hasActiveCallMembership(room, sender)) {
@@ -623,10 +613,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       }
       setTimeout(() => {
         if (Date.now() >= senderTs + lifetime) return;
-        if (
-          declinedRing(room, [refEventId, event.getId()], myUserId) ||
-          hasActiveCallMembership(room, myUserId)
-        ) {
+        if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
           return;
         }
         if (hasActiveCallMembership(room, sender)) setCallInfo(info);
@@ -698,10 +685,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       if (eventRoom?.roomId !== room.roomId || !data.liveEvent) return;
       if (event.getType() === EventType.RTCDecline && event.getSender() === myUserId) {
         const related = event.getRelation()?.event_id;
-        // [Gitea #313] Correct clients reference the notification; older Lotus
-        // builds referenced the call membership. Accept both.
-        if (!related || related === refEventId || related === callInfo.notificationEventId)
-          dismiss(); // declined elsewhere
+        if (!related || related === refEventId) dismiss(); // declined elsewhere
       }
     };
     session.on(MatrixRTCSessionEvent.MembershipsChanged, checkMemberships);

src/app/components/create-room/utils.ts

@@ -139,8 +139,11 @@ export const createRoom = async (mx: MatrixClient, data: CreateRoomData): Promis
       data.allowFederation,
       data.additionalCreators,
     ),
-    power_level_content_override:
-      data.type === RoomType.Call ? createVoiceRoomPowerLevelsOverride() : undefined,
+    // [Gitea #328] Every non-space room gets call.member at user level, not just
+    // voice rooms: the call button is shown in private group rooms too, and with
+    // Synapse's state_default (50) only admins could start or join a call there
+    // ("You don't have permission to join!").
+    power_level_content_override: createVoiceRoomPowerLevelsOverride(),
     initial_state: initialState,
   };
 

src/app/features/room/RoomTimeline.tsx

@@ -138,7 +138,7 @@ import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { useIgnoredUsers } from '../../hooks/useIgnoredUsers';
 import { useImagePackRooms } from '../../hooks/useImagePackRooms';
 import { useIsDirectRoom } from '../../hooks/useRoom';
-import { declinedRing, isRingableRoom } from '../../utils/callRing';
+import { isRingableRoom } from '../../utils/callRing';
 import { useOpenUserRoomProfile } from '../../state/hooks/userRoomProfile';
 import { useSpaceOptionally } from '../../hooks/useSpace';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
@@ -2037,9 +2037,6 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         // Same rule as ringing: no "Missed call" in voice rooms or space
         // channels, where starting a call is just joining the channel.
         if (!isRingableRoom(room, direct)) return null;
-        // [Gitea #313] A call we declined isn't a missed call.
-        const ringRef = mEvent.getRelation()?.event_id;
-        if (declinedRing(room, [mEventId, ringRef], mx.getSafeUserId())) return null;
         const content = mEvent.getContent();
         const mention =
           content['m.mentions']?.room ||

src/app/features/room/message/Reactions.tsx

@@ -69,8 +69,15 @@ export const Reactions = as<'div', ReactionsProps>(
     const measure = useCallback(() => {
       const container = containerRef.current;
       if (!container) return;
-      const rowWidth = container.getBoundingClientRect().width;
-      const gap = parseFloat(getComputedStyle(container).columnGap) || 8;
+      // [Gitea #305] The width the chips actually get (content box). The border
+      // box grows by 4 px while collapsed (margin -2 / padding 2), and measuring
+      // it made a row within 4 px of fitting flip collapsed↔expanded every frame.
+      const cs = getComputedStyle(container);
+      const rowWidth =
+        container.clientWidth -
+        (parseFloat(cs.paddingLeft) || 0) -
+        (parseFloat(cs.paddingRight) || 0);
+      const gap = parseFloat(cs.columnGap) || 8;
       const chips = keys ? keys.split('\u0000').map((k) => chipRefs.current.get(k)) : [];
       const widths = chips.map((el) => el?.getBoundingClientRect().width ?? 0);
       const moreWidth = moreRef.current?.getBoundingClientRect().width ?? 48;
@@ -110,8 +117,21 @@ export const Reactions = as<'div', ReactionsProps>(
         style={{
           ...props.style,
           ...(collapsed && rowHeight
-            ? // 2px breathing room so row-1 focus outlines are not clipped.
-              { maxHeight: rowHeight + 4, overflow: 'hidden', padding: 2, margin: -2 }
+            ? // 2px breathing room so row-1 focus outlines are not clipped. Longhand
+              // margins so the timeline's marginTop survives (Gitea #305: the
+              // `margin` shorthand overrode it and, once removed, cleared it).
+              {
+                maxHeight: rowHeight + 4,
+                overflow: 'hidden',
+                padding: 2,
+                marginLeft: -2,
+                marginRight: -2,
+                marginBottom: -2,
+                marginTop:
+                  props.style?.marginTop !== undefined
+                    ? `calc(${typeof props.style.marginTop === 'number' ? `${props.style.marginTop}px` : props.style.marginTop} - 2px)`
+                    : -2,
+              }
             : {}),
         }}
         ref={(el) => {

src/app/pages/client/ClientNonUIFeatures.tsx

@@ -571,7 +571,8 @@ function MessageNotifications() {
                 // NotificationOptions typing.
                 actions: [{ action: 'reply', title: 'Reply', type: 'text', placeholder: 'Reply…' }],
               }),
-          data: { path: roomPath, roomId, threadId: threadId || undefined },
+          // userId: [Gitea #299] the SW replies as this account only.
+          data: { path: roomPath, roomId, threadId: threadId || undefined, userId: mx.getUserId() },
         },
         () => {
           window.focus();
@@ -579,7 +580,7 @@ function MessageNotifications() {
         },
       );
     },
-    [navigate, setToast, mDirects],
+    [navigate, setToast, mDirects, mx],
   );
 
   // N105: when a service-worker-owned notification is clicked, the SW focuses

src/app/plugins/call/CallEmbed.ts

@@ -31,6 +31,7 @@ import { verifyDenoiseAssets } from './denoiseSmokeCheck';
 import { canDelegateCapability } from './utils';
 import { getCallPageUrl } from './callPageUrl';
 import { restrictWidgetMessages } from '../widgetTransport';
+import { isRingableRoom } from '../../utils/callRing';
 
 // Maximum time to wait for the embedded Element Call iframe to progress from
 // initial load to a ready/joined state. If it hasn't by then, we assume the
@@ -251,8 +252,18 @@ export class CallEmbed {
       verifyDenoiseAssets(denoiseModel).catch(() => undefined);
     }
 
+    // [Gitea #295] Only ask Element Call to notify where a call can ring at all
+    // (DMs, invite-only groups outside a space). In a voice channel or space
+    // room the notification carries an @room mention, so every member got a
+    // highlighted ping (and phone push) whenever a moderator hopped in, and
+    // other clients showed it as a missed call.
+    // `none` needs element-call-embedded ≥ 0.25.0-lotus.23 (older builds ignore it).
     if (CallEmbed.startingCall(intent)) {
-      params.append('sendNotificationType', CallEmbed.dmCall(intent) ? 'ring' : 'notification');
+      let notify = 'none';
+      if (isRingableRoom(room, CallEmbed.dmCall(intent))) {
+        notify = CallEmbed.dmCall(intent) ? 'ring' : 'notification';
+      }
+      params.append('sendNotificationType', notify);
     }
 
     // [Gitea #43] On its own origin when config.json sets elementCallUrl.

src/app/utils/callRing.test.ts

@@ -67,18 +67,3 @@ test('declinedRing finds our own decline of that ring only (#312)', () => {
   assert.equal(declinedRing(room, '$ring2', '@me:x'), false, "someone else's decline");
   assert.equal(declinedRing(room, '$ring3', '@me:x'), false);
 });
-
-test('declinedRing matches a decline of the notification or of the membership (#313)', () => {
-  const decline = (rel: string) => ({
-    getType: () => 'org.matrix.msc4310.rtc.decline',
-    getSender: () => '@me:x',
-    getRelation: () => ({ event_id: rel }),
-  });
-  const room = stateRoom([], [decline('$notification')]);
-  assert.equal(declinedRing(room, ['$membership', '$notification'], '@me:x'), true);
-  assert.equal(declinedRing(room, ['$membership'], '@me:x'), false);
-  assert.equal(
-    declinedRing(stateRoom([], [decline('$membership')]), ['$membership', undefined], '@me:x'),
-    true,
-  );
-});

src/app/utils/callRing.ts

@@ -40,18 +40,7 @@ export const hasActiveCallMembership = (room: Room, userId: string): boolean =>
  * declined it (our own RTCDecline relates to it) — e.g. replayed together with
  * the ring in the first sync after a restart, before any dismiss listener.
  */
-export const declinedRing = (
-  room: Room,
-  ringIds: string | Array<string | undefined>,
-  myUserId: string,
-): boolean => {
-  // [Gitea #313] A decline references the notification event (MSC4310); older
-  // Lotus builds referenced the call membership instead. Match either.
-  const ids = new Set((Array.isArray(ringIds) ? ringIds : [ringIds]).filter(Boolean));
-  return declinedAny(room, ids, myUserId);
-};
-
-const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string): boolean =>
+export const declinedRing = (room: Room, refEventId: string, myUserId: string): boolean =>
   room
     .getLiveTimeline()
     .getEvents()
@@ -59,5 +48,5 @@ const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string)
       (ev) =>
         ev.getType() === 'org.matrix.msc4310.rtc.decline' &&
         ev.getSender() === myUserId &&
-        ids.has(ev.getRelation()?.event_id),
+        ev.getRelation()?.event_id === refEventId,
     );

src/index.tsx

@@ -43,7 +43,7 @@ if ('serviceWorker' in navigator && swProtocolOk) {
 
   const sendSessionToSW = () => {
     const session = getFallbackSession();
-    pushSessionToSW(session?.baseUrl, session?.accessToken);
+    pushSessionToSW(session?.baseUrl, session?.accessToken, session?.userId);
   };
 
   // The dev worker is an ES module (it imports workbox), so it must be

src/sw-session.ts

@@ -1,4 +1,4 @@
-export function pushSessionToSW(baseUrl?: string, accessToken?: string) {
+export function pushSessionToSW(baseUrl?: string, accessToken?: string, userId?: string) {
   if (!('serviceWorker' in navigator)) return;
   if (!navigator.serviceWorker.controller) return;
 
@@ -6,5 +6,6 @@ export function pushSessionToSW(baseUrl?: string, accessToken?: string) {
     type: 'setSession',
     accessToken,
     baseUrl,
+    userId,
   });
 }

src/sw.ts

@@ -2,7 +2,7 @@
 
 import { precacheAndRoute, type PrecacheEntry } from 'workbox-precaching';
 import { SHARE_TARGET_PATH, stashSharedForm } from './swShare';
-import { sendNotificationReply } from './swReply';
+import { pickReplySession, replyFailureText, sendNotificationReply } from './swReply';
 
 export type {};
 declare const self: ServiceWorkerGlobalScope & {
@@ -40,6 +40,8 @@ precacheAndRoute(self.__WB_MANIFEST);
 type SessionInfo = {
   accessToken: string;
   baseUrl: string;
+  /** [Gitea #299] whose session this is, so a notification reply uses its own account */
+  userId?: string;
 };
 
 /**
@@ -63,9 +65,13 @@ async function cleanupDeadClients() {
   });
 }
 
-function setSession(clientId: string, accessToken: string, baseUrl: string) {
+function setSession(clientId: string, accessToken: string, baseUrl: string, userId?: unknown) {
   if (typeof accessToken === 'string' && typeof baseUrl === 'string') {
-    sessions.set(clientId, { accessToken, baseUrl });
+    sessions.set(clientId, {
+      accessToken,
+      baseUrl,
+      userId: typeof userId === 'string' ? userId : undefined,
+    });
   } else {
     // Logout or invalid session
     sessions.delete(clientId);
@@ -130,10 +136,10 @@ self.addEventListener('message', (event: ExtendableMessageEvent) => {
   const client = event.source as Client | null;
   if (!client) return;
 
-  const { type, accessToken, baseUrl } = event.data || {};
+  const { type, accessToken, baseUrl, userId } = event.data || {};
 
   if (type === 'setSession') {
-    setSession(client.id, accessToken, baseUrl);
+    setSession(client.id, accessToken, baseUrl, userId);
     cleanupDeadClients();
   }
 });
@@ -155,15 +161,19 @@ self.addEventListener('notificationclick', (event: NotificationEvent) => {
     if (text) {
       event.waitUntil(
         sendNotificationReply(
-          Array.from(sessions.values()).pop(),
+          // [Gitea #299] The notification's own account, not the newest session.
+          pickReplySession(
+            Array.from(sessions.values()),
+            typeof data.userId === 'string' ? data.userId : undefined,
+          ),
           data.roomId,
           data.threadId,
           text,
-        ).then((ok) => {
-          if (!ok) {
+        ).then((result) => {
+          if (result !== 'sent') {
             // Let the user know it didn't go out, and keep their text reachable.
             return self.registration.showNotification('Reply not sent', {
-              body: `Couldn't send "${text.slice(0, 60)}" — open the app to retry.`,
+              body: replyFailureText(result, text),
               tag: `swreply-fail-${data.roomId}`,
               data: { path },
             });

src/swReply.test.ts

@@ -1,6 +1,12 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { buildReplyContent, replySendUrl, sendNotificationReply } from './swReply';
+import {
+  buildReplyContent,
+  pickReplySession,
+  replyFailureText,
+  replySendUrl,
+  sendNotificationReply,
+} from './swReply';
 
 test('thread replies carry the m.thread relation, room replies do not', () => {
   assert.deepEqual(buildReplyContent('hi'), { msgtype: 'm.text', body: 'hi', 'm.mentions': {} });
@@ -19,40 +25,64 @@ test('send URL encodes the room id against the session base URL', () => {
   );
 });
 
-test('sendNotificationReply PUTs with the bearer token and reports ok / failure', async () => {
+test('sendNotificationReply checks encryption, then PUTs with the bearer token (#203, #299)', async () => {
   const calls: { url: string; init: RequestInit }[] = [];
-  const fetchOk = (async (url: string, init: RequestInit) => {
-    calls.push({ url, init });
-    return { ok: true } as Response;
-  }) as unknown as typeof fetch;
-  assert.equal(
-    await sendNotificationReply(
-      { accessToken: 'tok', baseUrl: 'https://hs' },
-      '!r:hs',
-      '$t',
-      'yo',
-      fetchOk,
-    ),
-    true,
-  );
-  assert.equal(calls[0].init.method, 'PUT');
-  assert.equal((calls[0].init.headers as Record<string, string>).Authorization, 'Bearer tok');
+  const fetchFor = (encStatus: number, sendOk = true) =>
+    (async (url: string, init: RequestInit = {}) => {
+      calls.push({ url, init });
+      if (url.includes('/state/m.room.encryption/')) {
+        return { ok: encStatus === 200, status: encStatus } as Response;
+      }
+      return { ok: sendOk, status: sendOk ? 200 : 500 } as Response;
+    }) as unknown as typeof fetch;
+  const session = { accessToken: 'tok', baseUrl: 'https://hs' };
+
+  assert.equal(await sendNotificationReply(session, '!r:hs', '$t', 'yo', fetchFor(404)), 'sent');
+  assert.match(calls[0].url, /\/rooms\/!r%3Ahs\/state\/m\.room\.encryption\/$/);
+  const put = calls[1];
+  assert.equal(put.init.method, 'PUT');
+  assert.equal((put.init.headers as Record<string, string>).Authorization, 'Bearer tok');
   assert.match(
-    calls[0].url,
+    put.url,
     /^https:\/\/hs\/_matrix\/client\/v3\/rooms\/!r%3Ahs\/send\/m\.room\.message\/swreply-/,
   );
-  assert.equal(JSON.parse(calls[0].init.body as string)['m.relates_to'].event_id, '$t');
+  assert.equal(JSON.parse(put.init.body as string)['m.relates_to'].event_id, '$t');
 
-  const fetchFail = (async () => ({ ok: false }) as Response) as unknown as typeof fetch;
+  // Encryption turned on since the notification was shown: nothing is sent.
+  calls.length = 0;
   assert.equal(
-    await sendNotificationReply(
-      { accessToken: 'tok', baseUrl: 'https://hs' },
-      '!r:hs',
-      undefined,
-      'yo',
-      fetchFail,
-    ),
-    false,
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(200)),
+    'encrypted',
+  );
+  assert.equal(calls.length, 1);
+  // Can't tell (server error): fail safe, nothing is sent.
+  calls.length = 0;
+  assert.equal(
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(500)),
+    'failed',
+  );
+  assert.equal(calls.length, 1);
+  assert.equal(
+    await sendNotificationReply(session, '!r:hs', undefined, 'yo', fetchFor(404, false)),
+    'failed',
+  );
+  assert.equal(
+    await sendNotificationReply(undefined, '!r:hs', undefined, 'yo', fetchFor(404)),
+    'no-session',
   );
-  assert.equal(await sendNotificationReply(undefined, '!r:hs', undefined, 'yo', fetchOk), false);
+});
+
+test('pickReplySession: the notification account only (#299)', () => {
+  const a = { accessToken: 'a', baseUrl: 'https://hs', userId: '@a:hs' };
+  const b = { accessToken: 'b', baseUrl: 'https://hs', userId: '@b:hs' };
+  assert.equal(pickReplySession([a, b], '@a:hs'), a);
+  assert.equal(pickReplySession([b], '@a:hs'), undefined, 'logged out of @a here');
+  assert.equal(pickReplySession([a], undefined), a, 'old notification, one session');
+  assert.equal(pickReplySession([a, b], undefined), undefined, 'old notification, ambiguous');
+});
+
+test('replyFailureText says why', () => {
+  assert.match(replyFailureText('encrypted', 'hi'), /now encrypted/);
+  assert.match(replyFailureText('no-session', 'hi'), /no longer signed in/);
+  assert.match(replyFailureText('failed', 'hi'), /retry/);
 });

src/swReply.ts

@@ -1,9 +1,42 @@
 /**
  * [Gitea #203] Build and send an inline reply typed into a notification's
  * text action. Lives outside sw.ts so it can be unit-tested; the SW passes in
- * its newest known session and the global fetch.
+ * the notification account's session and the global fetch.
  */
-export type SwReplySession = { accessToken: string; baseUrl: string };
+export type SwReplySession = { accessToken: string; baseUrl: string; userId?: string };
+
+export type SwReplyResult = 'sent' | 'failed' | 'encrypted' | 'no-session';
+
+/**
+ * [Gitea #299] The session to reply with: the notification's own account. A
+ * notification without a user id (shown before this change) may only use the
+ * session if it is the only one, so a reply never posts as another account.
+ */
+export const pickReplySession = (
+  sessions: SwReplySession[],
+  userId: string | undefined,
+): SwReplySession | undefined => {
+  if (userId) return sessions.filter((x) => x.userId === userId).pop();
+  return sessions.length === 1 ? sessions[0] : undefined;
+};
+
+/** What the "Reply not sent" notification says for each failure. */
+export const replyFailureText = (result: SwReplyResult, text: string): string => {
+  const quoted = `"${text.slice(0, 60)}"`;
+  if (result === 'encrypted') {
+    return `This room is now encrypted, so ${quoted} wasn't sent. Open the app to reply.`;
+  }
+  if (result === 'no-session') {
+    return `You're no longer signed in to that account here, so ${quoted} wasn't sent.`;
+  }
+  return `Couldn't send ${quoted}. Open the app to retry.`;
+};
+
+export const encryptionStateUrl = (baseUrl: string, roomId: string): string =>
+  new URL(
+    `/_matrix/client/v3/rooms/${encodeURIComponent(roomId)}/state/m.room.encryption/`,
+    baseUrl,
+  ).href;
 
 export const buildReplyContent = (text: string, threadId?: string): Record<string, unknown> => {
   const content: Record<string, unknown> = { msgtype: 'm.text', body: text, 'm.mentions': {} };
@@ -30,20 +63,24 @@ export async function sendNotificationReply(
   threadId: string | undefined,
   text: string,
   fetchFn: typeof fetch = fetch,
-): Promise<boolean> {
-  if (!session?.accessToken || !session.baseUrl) return false;
-  const txn = `swreply-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+): Promise<SwReplyResult> {
+  if (!session?.accessToken || !session.baseUrl) return 'no-session';
+  const headers = { Authorization: `Bearer ${session.accessToken}` };
   try {
+    // [Gitea #299] The SW can't encrypt, and the reply action was offered when
+    // the notification was shown — possibly hours ago. Re-check now: only a
+    // definite "no encryption state" (404) lets the plain reply go out.
+    const enc = await fetchFn(encryptionStateUrl(session.baseUrl, roomId), { headers });
+    if (enc.ok) return 'encrypted';
+    if (enc.status !== 404) return 'failed';
+    const txn = `swreply-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
     const res = await fetchFn(replySendUrl(session.baseUrl, roomId, txn), {
       method: 'PUT',
-      headers: {
-        Authorization: `Bearer ${session.accessToken}`,
-        'Content-Type': 'application/json',
-      },
+      headers: { ...headers, 'Content-Type': 'application/json' },
       body: JSON.stringify(buildReplyContent(text, threadId)),
     });
-    return res.ok;
+    return res.ok ? 'sent' : 'failed';
   } catch {
-    return false;
+    return 'failed';
   }
 }