Enforce DM call switching and foreground native call ownership

android/app/src/main/java/chat/vojo/app/VojoFirebaseMessagingService.java

@@ -29,13 +29,13 @@ import java.util.Map;
  * Message branch: builds a system notification when the activity is NOT in
  * the foreground — covering both "backgrounded" and "killed" cases.
  *
- * Call branch: for `org.matrix.msc4075.rtc.notification` + `notification_type=ring`
+ * Call branch: when the app is backgrounded we show a CallStyle incoming-call
- * we always show a CallStyle incoming-call notification (independent of
+ * notification with Answer/Decline actions + full-screen intent that wakes the
- * foreground state) with Answer/Decline actions + full-screen intent that
+ * device and launches MainActivity over the lockscreen. When the app is already
- * wakes the device and launches MainActivity over the lockscreen — the
+ * foregrounded, JS owns the UX via the in-app incoming-call strip, so we must
- * WhatsApp/Telegram incoming-call UX. The FSI is also what satisfies AOSP
+ * NOT also surface a system banner. The FSI is also what satisfies AOSP
- * NotificationManagerService.checkDisqualifyingFeatures on API 31+; without
+ * NotificationManagerService.checkDisqualifyingFeatures on API 31+; without it
- * it CallStyle throws IAE and the notification is silently dropped. See
+ * CallStyle throws IAE and the notification is silently dropped. See
  * docs/plans/dm_calls.md ADR 2.5-fsi.
  */
 public class VojoFirebaseMessagingService extends MessagingService {
@@ -72,7 +72,11 @@ public class VojoFirebaseMessagingService extends MessagingService {
         try {
             if (RTC_NOTIFICATION_TYPE.equals(data.get("type"))
                 && "ring".equals(data.get("content_notification_type"))) {
-                Log.d(TAG, "route: call-branch");
+                if (MainActivity.isInForeground) {
+                    Log.d(TAG, "route: skip call notif (foreground, JS strip owns UX)");
+                    return;
+                }
+                Log.d(TAG, "route: call-branch (background)");
                 showIncomingCallNotification(remoteMessage);
                 return;
             }

src/app/components/CallEmbedProvider.tsx

@@ -1,5 +1,5 @@
 import React, { ReactNode, useCallback, useRef } from 'react';
-import { useAtomValue, useSetAtom } from 'jotai';
+import { useAtomValue, useSetAtom, useStore } from 'jotai';
 import {
   CallEmbedContextProvider,
   CallEmbedRefContextProvider,
@@ -15,14 +15,16 @@ import { ScreenSize, useScreenSizeContext } from '../hooks/useScreenSize';
 
 function CallUtils({ embed }: { embed: CallEmbed }) {
   const setCallEmbed = useSetAtom(callEmbedAtom);
+  const store = useStore();
 
   useCallMemberSoundSync(embed);
   useCallThemeSync(embed);
   useCallHangupEvent(
     embed,
     useCallback(() => {
+      if (store.get(callEmbedAtom) !== embed) return;
       setCallEmbed(undefined);
-    }, [setCallEmbed])
+    }, [store, embed, setCallEmbed])
   );
 
   return null;

src/app/features/call-status/IncomingCallStrip.tsx

@@ -12,7 +12,7 @@ import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { UserAvatar } from '../../components/user-avatar';
 import { getMemberAvatarMxc, getMemberDisplayName } from '../../utils/room';
 import { getCanonicalAliasOrRoomId, getMxIdLocalPart, mxcUrlToHttp } from '../../utils/matrix';
-import { useDmCallStart } from '../../hooks/useDmCallStart';
+import { useSwitchOrStartDmCall } from '../../hooks/useSwitchOrStartDmCall';
 import { getDirectRoomPath } from '../../pages/pathUtils';
 import { IncomingCall, incomingCallsAtom } from '../../state/incomingCalls';
 import { getIncomingCallKey } from '../../utils/rtcNotification';
@@ -28,7 +28,7 @@ export function IncomingCallStrip({ call, room }: IncomingCallStripProps) {
   const mx = useMatrixClient();
   const navigate = useNavigate();
   const useAuthentication = useMediaAuthentication();
-  const startDmCall = useDmCallStart();
+  const switchOrStartDmCall = useSwitchOrStartDmCall();
   const setIncoming = useSetAtom(incomingCallsAtom);
 
   const senderId = call.notifEvent.getSender();
@@ -45,9 +45,20 @@ export function IncomingCallStrip({ call, room }: IncomingCallStripProps) {
   const callKey = getIncomingCallKey(call.callId, call.roomId);
 
   const handleAnswer = () => {
-    setIncoming({ type: 'REMOVE', key: callKey });
-    startDmCall(call.roomId);
     navigate(getDirectRoomPath(getCanonicalAliasOrRoomId(mx, call.roomId)));
+    switchOrStartDmCall(call.roomId)
+      .then(() => {
+        const evId = call.notifEvent.getId();
+        if (evId) {
+          setIncoming({ type: 'REMOVE_BY_NOTIF_ID', notifEventId: evId });
+          return;
+        }
+        setIncoming({ type: 'REMOVE', key: callKey });
+      })
+      .catch((err: unknown) => {
+        // eslint-disable-next-line no-console
+        console.warn('[call] strip answer switch/start failed', err);
+      });
   };
 
   const handleDecline = async () => {

src/app/features/room/RoomViewHeader.tsx

@@ -72,7 +72,7 @@ import { ContainerColor } from '../../styles/ContainerColor.css';
 import { RoomSettingsPage } from '../../state/roomSettings';
 import { useLivekitSupport } from '../../hooks/useLivekitSupport';
 import { useCallMembers, useCallSession } from '../../hooks/useCall';
-import { useDmCallStart } from '../../hooks/useDmCallStart';
+import { useSwitchOrStartDmCall } from '../../hooks/useSwitchOrStartDmCall';
 import { callEmbedAtom } from '../../state/callEmbed';
 
 type RoomMenuProps = {
@@ -263,7 +263,7 @@ const RoomMenu = forwardRef<HTMLDivElement, RoomMenuProps>(({ room, requestClose
 function DmCallButton({ room }: { room: Room }) {
   const { t } = useTranslation();
   const mx = useMatrixClient();
-  const startDmCall = useDmCallStart();
+  const switchOrStartDmCall = useSwitchOrStartDmCall();
   const livekitSupported = useLivekitSupport();
   const session = useCallSession(room);
   const members = useCallMembers(room, session);
@@ -273,19 +273,20 @@ function DmCallButton({ room }: { room: Room }) {
   const inCallHere = currentEmbed?.roomId === room.roomId;
   if (inCallHere) return null;
 
-  const inCallElsewhere = !!currentEmbed && currentEmbed.roomId !== room.roomId;
   const ongoingByOthers = members.length > 0 && !members.some((m) => m.sender === myUserId);
 
-  const disabled = !livekitSupported || inCallElsewhere;
+  const disabled = !livekitSupported;
   let tooltipText: string;
   if (!livekitSupported) tooltipText = t('Call.unavailable');
-  else if (inCallElsewhere) tooltipText = t('Call.busy_other_room');
   else if (ongoingByOthers) tooltipText = t('Call.join');
   else tooltipText = t('Call.start');
 
   const handleClick = () => {
     if (disabled) return;
-    startDmCall(room.roomId);
+    switchOrStartDmCall(room.roomId).catch((err: unknown) => {
+      // eslint-disable-next-line no-console
+      console.warn('[call] header switch/start failed', err);
+    });
   };
 
   return (

src/app/hooks/useCallerAutoHangup.ts

@@ -10,9 +10,7 @@
 //   3. Peer joins then leaves — memberships go empty → hangup after grace.
 //   4. Peer membership flaps on LiveKit reconnect — grace absorbs the blip.
 //
-// KNOWN GAPS (also in dm_calls_techdebt.md):
+// KNOWN GAP (also in dm_calls_techdebt.md):
-//   §5.16 Decline is not tied to our specific ring event id. Any RTCDecline
-//         from peer in this room kills our call.
 //   §5.18 Grace constants are empirically chosen, may need tuning with
 //         real-world /sync + LiveKit reconnect metrics.
 //
@@ -34,6 +32,7 @@ import {
 } from 'matrix-js-sdk';
 import { CallMembership } from 'matrix-js-sdk/lib/matrixrtc/CallMembership';
 import { MatrixRTCSessionEvent } from 'matrix-js-sdk/lib/matrixrtc/MatrixRTCSession';
+import { IRTCNotificationContent } from 'matrix-js-sdk/lib/matrixrtc/types';
 import { useMatrixClient } from './useMatrixClient';
 import { callEmbedAtom } from '../state/callEmbed';
 import { mDirectAtom } from '../state/mDirectList';
@@ -48,6 +47,21 @@ const NO_ANSWER_GRACE_MS = 10_000;
 // grace we'd kill a live call on every blip.
 const PEER_LEAVE_GRACE_MS = 8_000;
 
+const findLatestOwnRingNotifEvent = (
+  selfId: string,
+  events: MatrixEvent[]
+): MatrixEvent | undefined => {
+  for (let i = events.length - 1; i >= 0; i -= 1) {
+    const ev = events[i];
+    if (ev.getSender() === selfId && ev.getType() === EventType.RTCNotification) {
+      const content = ev.getContent<IRTCNotificationContent>();
+      if (content.notification_type === 'ring') return ev;
+    }
+  }
+
+  return undefined;
+};
+
 export const useCallerAutoHangup = (): void => {
   const mx = useMatrixClient();
   const callEmbed = useAtomValue(callEmbedAtom);
@@ -56,7 +70,7 @@ export const useCallerAutoHangup = (): void => {
 
   useEffect(() => {
     if (!callEmbed) return undefined;
-    const roomId = callEmbed.roomId;
+    const { roomId } = callEmbed;
     if (!mDirect.has(roomId)) return undefined;
 
     const selfId = mx.getUserId();
@@ -71,6 +85,11 @@ export const useCallerAutoHangup = (): void => {
     let disposed = false;
     let peerSeen = session.memberships.some((m) => !isSelf(m));
     let peerLeaveTimer: ReturnType<typeof setTimeout> | undefined;
+    let ownRingNotifEvent = findLatestOwnRingNotifEvent(
+      selfId,
+      callEmbed.room.getLiveTimeline()?.getEvents() ?? []
+    );
+    let pendingDeclineForNotifEventId: string | undefined;
 
     const performHangup = () => {
       if (disposed) return;
@@ -108,12 +127,40 @@ export const useCallerAutoHangup = (): void => {
       }
     };
 
+    const maybeTrackOwnRing = (ev: MatrixEvent): void => {
+      if (ev.getRoomId() !== roomId) return;
+      if (ev.getType() !== EventType.RTCNotification) return;
+      if (ev.getSender() !== selfId) return;
+      const content = ev.getContent<IRTCNotificationContent>();
+      if (content.notification_type !== 'ring') return;
+      ownRingNotifEvent = ev;
+      if (pendingDeclineForNotifEventId === ev.getId()) {
+        performHangup();
+      }
+    };
+
     const maybeHangupOnDecline = (ev: MatrixEvent): void => {
       // onDecrypted fires for every decrypted event client-wide; gate on room
       // first to avoid walking type/sender on unrelated rooms.
       if (ev.getRoomId() !== roomId) return;
       if (ev.getType() !== EventType.RTCDecline) return;
       if (ev.getSender() === selfId) return;
+      const declinedNotifEventId = ev.getRelation()?.event_id;
+      if (!declinedNotifEventId) return;
+
+      // Same-room retries can leave multiple historical ring events behind.
+      // We only honor a decline that targets the ring this embed most recently
+      // sent; older declines must not tear down the new attempt.
+      if (!ownRingNotifEvent) {
+        pendingDeclineForNotifEventId = declinedNotifEventId;
+        return;
+      }
+      if (declinedNotifEventId !== ownRingNotifEvent.getId()) {
+        if (ownRingNotifEvent.getAssociatedStatus() !== null) {
+          pendingDeclineForNotifEventId = declinedNotifEventId;
+        }
+        return;
+      }
       performHangup();
     };
 
@@ -123,20 +170,30 @@ export const useCallerAutoHangup = (): void => {
       // Encrypted RTCDecline lands as m.room.encrypted here; let the Decrypted
       // handler see it once cleartext is available.
       if (ev.isEncrypted()) {
-        mx.decryptEventIfNeeded(ev).catch(() => {});
+        mx.decryptEventIfNeeded(ev).catch(() => undefined);
         return;
       }
+      maybeTrackOwnRing(ev);
       maybeHangupOnDecline(ev);
     };
 
     const onDecrypted: MatrixEventHandlerMap[MatrixEventEvent.Decrypted] = (ev, err) => {
       if (err) return;
+      maybeTrackOwnRing(ev);
       maybeHangupOnDecline(ev);
     };
 
+    const onLocalEchoUpdated: RoomEventHandlerMap[RoomEvent.LocalEchoUpdated] = (ev, room) => {
+      if (!room || room.roomId !== roomId) return;
+      if (ev !== ownRingNotifEvent) return;
+      if (pendingDeclineForNotifEventId !== ev.getId()) return;
+      performHangup();
+    };
+
     session.on(MatrixRTCSessionEvent.MembershipsChanged, onMemberships);
     mx.on(RoomEvent.Timeline, onTimeline);
     mx.on(MatrixEventEvent.Decrypted, onDecrypted);
+    mx.on(RoomEvent.LocalEchoUpdated, onLocalEchoUpdated);
 
     return () => {
       disposed = true;
@@ -145,6 +202,7 @@ export const useCallerAutoHangup = (): void => {
       session.off(MatrixRTCSessionEvent.MembershipsChanged, onMemberships);
       mx.removeListener(RoomEvent.Timeline, onTimeline);
       mx.removeListener(MatrixEventEvent.Decrypted, onDecrypted);
+      mx.removeListener(RoomEvent.LocalEchoUpdated, onLocalEchoUpdated);
     };
   }, [mx, callEmbed, mDirect, setCallEmbed]);
 };

src/app/hooks/useDismissNativeCallNotifications.ts

@@ -3,49 +3,7 @@ import { useAtomValue } from 'jotai';
 import { incomingCallsAtom } from '../state/incomingCalls';
 import { isNativePlatform } from '../utils/capacitor';
 
-// When the in-app incomingCallsAtom drops an entry (user accepted, declined,
+const SUMMARY_NOTIFICATION_ID = -2147483648;
-// other device joined, lifetime expired), also clear the CallStyle notification
-// the native service posted for that room. The AlarmManager fallback in the
-// Java service handles killed-process dismiss on lifetime expiry; this hook
-// covers the live-client paths where JS knows the truth sooner than the alarm.
-export const useDismissNativeCallNotifications = (): void => {
-  const incoming = useAtomValue(incomingCallsAtom);
-  const prevRoomsRef = useRef<Set<string>>(new Set());
-
-  useEffect(() => {
-    const nextRooms = new Set<string>();
-    incoming.forEach((call) => nextRooms.add(call.roomId));
-
-    const dropped: string[] = [];
-    prevRoomsRef.current.forEach((roomId) => {
-      if (!nextRooms.has(roomId)) dropped.push(roomId);
-    });
-    prevRoomsRef.current = nextRooms;
-
-    if (dropped.length === 0) return;
-    if (!isNativePlatform()) return;
-
-    (async () => {
-      const { PushNotifications } = await import('@capacitor/push-notifications');
-      // Shape mirrors VojoFirebaseMessagingService.showIncomingCallNotification:
-      //   tag = "call_" + roomId, id = tag.hashCode(). The Android Capacitor
-      //   plugin reads id via JSObject.getInteger (PushNotificationsPlugin.java
-      //   line 166), so the id must go over the bridge as a number — the TS
-      //   type declares string, hence the cast.
-      const notifications = dropped.map((roomId) => {
-        const tag = `call_${roomId}`;
-        return { id: javaStringHashCode(tag), tag };
-      });
-      await PushNotifications.removeDeliveredNotifications({
-        notifications: notifications as unknown as Parameters<
-          typeof PushNotifications.removeDeliveredNotifications
-        >[0]['notifications'],
-      }).catch(() => {
-        /* best-effort — alarm fallback still dismisses at lifetime expiry */
-      });
-    })();
-  }, [incoming]);
-};
 
 // Reproduces java.lang.String#hashCode so JS-side ids match the tag ids the
 // Java service computed. Must stay in sync with CallCancelReceiver / the
@@ -58,3 +16,52 @@ function javaStringHashCode(s: string): number {
   }
   return h;
 }
+
+// Keep native CallStyle in sync with the JS-owned incoming-calls atom. When JS
+// either loses a ring (accepted, declined, other device joined, lifetime
+// expired) OR newly takes ownership of one after the app returns foreground,
+// clear the system notification for that room. The AlarmManager fallback in the
+// Java service still handles killed-process dismiss on lifetime expiry.
+export const useDismissNativeCallNotifications = (): void => {
+  const incoming = useAtomValue(incomingCallsAtom);
+  const prevRoomsRef = useRef<Set<string>>(new Set());
+
+  useEffect(() => {
+    const nextRooms = new Set<string>();
+    incoming.forEach((call) => nextRooms.add(call.roomId));
+
+    const changed: string[] = [];
+    prevRoomsRef.current.forEach((roomId) => {
+      if (!nextRooms.has(roomId)) changed.push(roomId);
+    });
+    nextRooms.forEach((roomId) => {
+      if (!prevRoomsRef.current.has(roomId)) changed.push(roomId);
+    });
+    prevRoomsRef.current = nextRooms;
+
+    if (changed.length === 0) return;
+    if (!isNativePlatform()) return;
+
+    (async () => {
+      const { PushNotifications } = await import('@capacitor/push-notifications');
+      // Shape mirrors VojoFirebaseMessagingService.showIncomingCallNotification:
+      //   tag = "call_" + roomId, id = tag.hashCode(). The Android Capacitor
+      //   plugin reads id via JSObject.getInteger (PushNotificationsPlugin.java
+      //   line 166), so the id must go over the bridge as a number — the TS
+      //   type declares string, hence the cast.
+      const notifications = changed.map((roomId) => {
+        const tag = `call_${roomId}`;
+        let id = javaStringHashCode(tag);
+        if (id === SUMMARY_NOTIFICATION_ID) id += 1;
+        return { id, tag };
+      });
+      await PushNotifications.removeDeliveredNotifications({
+        notifications: notifications as unknown as Parameters<
+          typeof PushNotifications.removeDeliveredNotifications
+        >[0]['notifications'],
+      }).catch(() => {
+        /* best-effort — alarm fallback still dismisses at lifetime expiry */
+      });
+    })();
+  }, [incoming]);
+};

src/app/hooks/useDmCallStart.ts

@@ -1,24 +1,16 @@
 import { useCallback } from 'react';
-import { useAtomValue } from 'jotai';
+import { useSwitchOrStartDmCall } from './useSwitchOrStartDmCall';
-import { useMatrixClient } from './useMatrixClient';
-import { useCallStart } from './useCallEmbed';
-import { useCallPreferencesAtom } from '../state/hooks/callPreferences';
 
 export const useDmCallStart = () => {
-  const mx = useMatrixClient();
+  const switchOrStartDmCall = useSwitchOrStartDmCall();
-  const startCall = useCallStart(true, true);
-  const callPref = useAtomValue(useCallPreferencesAtom());
 
   return useCallback(
     (roomId: string) => {
-      const room = mx.getRoom(roomId);
+      switchOrStartDmCall(roomId).catch((err: unknown) => {
-      if (!room) {
         // eslint-disable-next-line no-console
-        console.warn('[dm-call] room not found', roomId);
+        console.warn('[dm-call] switch/start failed', err);
-        return;
+      });
-      }
-      startCall(room, callPref);
     },
-    [mx, startCall, callPref]
+    [switchOrStartDmCall]
   );
 };

src/app/hooks/useIncomingRtcNotifications.ts

@@ -90,10 +90,7 @@ const resolveCallId = async (
   // Race: ring arrived before /sync delivered the membership state event.
   const session = mx.matrixRTC.getRoomSession(room);
   const waited = await new Promise<string | undefined>((resolve) => {
-    const timeout = setTimeout(() => {
+    let timeout: ReturnType<typeof setTimeout>;
-      session.off(MatrixRTCSessionEvent.MembershipsChanged, handler);
-      resolve(undefined);
-    }, 5000);
     const handler = () => {
       const found = findCallIdSync(mx, room, sender, membershipEventId);
       if (found !== undefined) {
@@ -102,6 +99,10 @@ const resolveCallId = async (
         resolve(found);
       }
     };
+    timeout = setTimeout(() => {
+      session.off(MatrixRTCSessionEvent.MembershipsChanged, handler);
+      resolve(undefined);
+    }, 5000);
     session.on(MatrixRTCSessionEvent.MembershipsChanged, handler);
   });
   if (waited !== undefined) return waited;
@@ -131,8 +132,6 @@ export const useIncomingRtcNotifications = (): void => {
 
   const mDirectRef = useRef(mDirect);
   mDirectRef.current = mDirect;
-  const inCallRef = useRef(callEmbed !== undefined);
-  inCallRef.current = callEmbed !== undefined;
 
   const registryRef = useRef<Map<string, RegistryEntry>>(new Map());
 
@@ -220,7 +219,6 @@ export const useIncomingRtcNotifications = (): void => {
       // Only DM ring — group call notifications use 'notification' type and are out of scope.
       if (content.notification_type !== 'ring') return;
       if (!mDirectRef.current.has(room.roomId)) return;
-      if (inCallRef.current) return;
       if (isRtcNotificationExpired(ev)) return;
 
       // Already participating in the room session → suppress duplicate toast.
@@ -241,7 +239,6 @@ export const useIncomingRtcNotifications = (): void => {
       // Re-check membership after the (possibly networked) callId resolve —
       // a join event from another device could have landed during the await.
       if (session.memberships.some((m) => m.sender === mx.getUserId())) return;
-      if (inCallRef.current) return;
 
       const key = getIncomingCallKey(callId, room.roomId);
       if (registry.has(key)) return;
@@ -274,7 +271,7 @@ export const useIncomingRtcNotifications = (): void => {
       // Encrypted events land here as m.room.encrypted; kick decryption and let
       // the Decrypted handler pick them up once the cleartext is available.
       if (ev.isEncrypted()) {
-        mx.decryptEventIfNeeded(ev).catch(() => {});
+        mx.decryptEventIfNeeded(ev).catch(() => undefined);
         return;
       }
       processEvent(ev, room);

src/app/hooks/usePendingCallActionConsumer.ts

@@ -3,54 +3,66 @@ import { useAtomValue, useSetAtom } from 'jotai';
 import { App } from '@capacitor/app';
 import { pendingCallActionAtom } from '../state/pendingCallAction';
 import { incomingCallsAtom } from '../state/incomingCalls';
-import { useDmCallStart } from './useDmCallStart';
 import { useMatrixClient } from './useMatrixClient';
 import { isNativePlatform } from '../utils/capacitor';
+import { useSwitchOrStartDmCall } from './useSwitchOrStartDmCall';
 
 // Consumes pending call actions emitted by the native Android push-action
 // listener (see usePushNotifications.ts). Must be mounted inside CallEmbedProvider
-// so useDmCallStart can reach the embed atom.
+// so useSwitchOrStartDmCall can reach the embed atom.
 export const usePendingCallActionConsumer = (): void => {
   const pending = useAtomValue(pendingCallActionAtom);
   const setPending = useSetAtom(pendingCallActionAtom);
   const setIncoming = useSetAtom(incomingCallsAtom);
-  const startDmCall = useDmCallStart();
+  const switchOrStartDmCall = useSwitchOrStartDmCall();
   const mx = useMatrixClient();
 
   useEffect(() => {
     if (!pending) return;
     if (pending.kind === 'answer') {
-      // In-app strip (if any) is stale after accept — drop it so the overlay
+      const { roomId, notifEventId } = pending;
-      // can own the UX without a parallel decline button lingering.
+      setPending(undefined);
-      setIncoming({ type: 'REMOVE_BY_ROOM', roomId: pending.roomId });
+      switchOrStartDmCall(roomId)
-      startDmCall(pending.roomId);
+        .then(() => {
-    } else {
+          if (notifEventId) {
-      // Unreachable in practice after techdebt §5.35 landed: every Decline
+            setIncoming({ type: 'REMOVE_BY_NOTIF_ID', notifEventId });
-      // button press now fires CallDeclineReceiver via PendingIntent.getBroadcast,
+            return;
-      // so MainActivity never boots and `pushNotificationActionPerformed` never
+          }
-      // fires with call_action='decline'. Nothing else queues a decline onto
+          setIncoming({ type: 'REMOVE_BY_ROOM', roomId });
-      // pendingCallActionAtom. Kept as a safety-net in case a future JS-path
+        })
-      // (in-app banner decline, retry flow, etc.) starts emitting here.
+        .catch((err: unknown) => {
-      setIncoming({ type: 'REMOVE_BY_NOTIF_ID', notifEventId: pending.notifEventId });
-      // Fire-and-minimize: dispatch the decline then minimize the app once the
-      // request settles (success OR failure). Minimizing before sendRtcDecline
-      // resolves risks the WebView getting paused mid-request on slower devices;
-      // waiting for settlement gives the network call the tick it needs.
-      const minimize = () => {
-        if (!isNativePlatform()) return;
-        App.minimizeApp().catch(() => {
-          /* minimize not supported / already in background */
-        });
-      };
-      mx.sendRtcDecline(pending.roomId, pending.notifEventId).then(
-        () => minimize(),
-        (err: unknown) => {
           // eslint-disable-next-line no-console
-          console.warn('[call] sendRtcDecline (from push action) failed', err);
+          console.warn('[call] native answer switch/start failed', err);
-          minimize();
+        });
-        }
+      return;
-      );
     }
+
+    const { roomId, notifEventId } = pending;
     setPending(undefined);
-  }, [pending, setPending, setIncoming, startDmCall, mx]);
+    // Unreachable in practice after techdebt §5.35 landed: every Decline
+    // button press now fires CallDeclineReceiver via PendingIntent.getBroadcast,
+    // so MainActivity never boots and `pushNotificationActionPerformed` never
+    // fires with call_action='decline'. Nothing else queues a decline onto
+    // pendingCallActionAtom. Kept as a safety-net in case a future JS-path
+    // (in-app banner decline, retry flow, etc.) starts emitting here.
+    setIncoming({ type: 'REMOVE_BY_NOTIF_ID', notifEventId });
+    // Fire-and-minimize: dispatch the decline then minimize the app once the
+    // request settles (success OR failure). Minimizing before sendRtcDecline
+    // resolves risks the WebView getting paused mid-request on slower devices;
+    // waiting for settlement gives the network call the tick it needs.
+    const minimize = () => {
+      if (!isNativePlatform()) return;
+      App.minimizeApp().catch(() => {
+        /* minimize not supported / already in background */
+      });
+    };
+    mx.sendRtcDecline(roomId, notifEventId).then(
+      () => minimize(),
+      (err: unknown) => {
+        // eslint-disable-next-line no-console
+        console.warn('[call] sendRtcDecline (from push action) failed', err);
+        minimize();
+      }
+    );
+  }, [pending, setPending, setIncoming, switchOrStartDmCall, mx]);
 };

src/app/hooks/usePushNotifications.ts

@@ -341,14 +341,19 @@ export function usePushNotificationsLifecycle(): void {
               notif_event_id?: string;
             };
 
-            // Native CallStyle Answer → open the room and queue an auto-join via
+            // Native CallStyle Answer → open the room and queue a JS-side
+            // switch/start via
             // pendingCallActionAtom. The consumer hook picks it up once the
             // CallEmbedProvider tree is mounted. DM rooms live in the Direct tab
             // route; `getHomeRoomPath` resolves to a Home-tab placeholder for IDs
             // it doesn't have in its left-rail, hence the DM path here.
             if (data.call_action === 'answer' && data.room_id) {
               navigate(getDirectRoomPath(data.room_id));
-              setPendingCallAction({ kind: 'answer', roomId: data.room_id });
+              setPendingCallAction({
+                kind: 'answer',
+                roomId: data.room_id,
+                notifEventId: data.notif_event_id,
+              });
               return;
             }
 
@@ -443,10 +448,12 @@ export function usePushNotificationsLifecycle(): void {
 
       // Display is handled entirely by the native VojoFirebaseMessagingService
       // (which fires for both backgrounded and killed process states via FCM's
-      // direct delivery). JS-side pushNotificationReceived would double-fire
+      // direct delivery). We intentionally do NOT subscribe to
-      // alongside native when the bridge is alive but backgrounded, so we don't
+      // `pushNotificationReceived` here: doing so would create a second incoming
-      // subscribe to it here — foreground dedup stays the in-app responsibility
+      // call delivery path next to the native service / timeline listener pair.
-      // (MessageNotifications cards), everything else goes through the native path.
+      // Foreground incoming-call UX is owned by the in-app strip via
+      // useIncomingRtcNotifications; background/killed UX is owned by native
+      // CallStyle. Keep this invariant unless the whole dedup model changes.
 
       // Kick off token delivery on startup if push was previously enabled and
       // permission is still granted. The listener above picks up the token.

src/app/hooks/useSwitchOrStartDmCall.ts

@@ -0,0 +1,146 @@
+// DM call entry point that unifies start, join and switch flows.
+//
+// Contract (dm_calls_techdebt.md §5.36):
+//   - no prev embed       → start a new DM call
+//   - prev.roomId === arg → no-op (healthy same-room click)
+//   - prev.roomId !== arg → switch: hangup prev, wait for clean leave,
+//     dispose prev, then start new
+//
+// Switch barrier waits for one of two success signals:
+//   1. MembershipsChanged removing our (user, device) from prev room session
+//      — server-authoritative, this is what the peer actually observes
+//   2. action:im.vector.hangup from the widget — widget-side confirmation,
+//      including pre-join / not-yet-member states where there is nothing to
+//      observe via MembershipsChanged
+//   3. 3s timeout — fail-closed: abort switch, do not start the new call
+//
+// Listeners are armed BEFORE hangup() to avoid missing a fast action ack.
+//
+// The function is serialized via inFlightRef: concurrent double-taps await the
+// same promise and then re-enter. After re-entry the same-room branch usually
+// makes the second tap a noop, matching user intent.
+
+import { useCallback, useRef } from 'react';
+import { useAtomValue, useStore } from 'jotai';
+import { CallMembership } from 'matrix-js-sdk/lib/matrixrtc/CallMembership';
+import { MatrixRTCSessionEvent } from 'matrix-js-sdk/lib/matrixrtc/MatrixRTCSession';
+import { useMatrixClient } from './useMatrixClient';
+import { useTheme } from './useTheme';
+import { createCallEmbed, useCallEmbedRef } from './useCallEmbed';
+import { useCallPreferencesAtom } from '../state/hooks/callPreferences';
+import { callEmbedAtom } from '../state/callEmbed';
+import { CallEmbed } from '../plugins/call';
+
+const SWITCH_LEAVE_TIMEOUT_MS = 3000;
+
+const createSwitchTimeoutError = (roomId: string): Error =>
+  new Error(`[dm-call] switch timed out waiting for clean leave in ${roomId}`);
+
+export const useSwitchOrStartDmCall = (): ((roomId: string) => Promise<void>) => {
+  const mx = useMatrixClient();
+  const theme = useTheme();
+  const store = useStore();
+  const callEmbedRef = useCallEmbedRef();
+  const callPref = useAtomValue(useCallPreferencesAtom());
+
+  const inFlightRef = useRef<Promise<void> | undefined>(undefined);
+
+  const waitLeave = useCallback(
+    (prev: CallEmbed): Promise<void> => {
+      const session = mx.matrixRTC.getRoomSession(prev.room);
+      const selfUserId = mx.getSafeUserId();
+      const selfDeviceId = mx.getDeviceId();
+      const selfPresent = (memberships: CallMembership[]): boolean =>
+        memberships.some(
+          (m) => m.sender === selfUserId && (!selfDeviceId || m.deviceId === selfDeviceId)
+        );
+
+      return new Promise<void>((resolve, reject) => {
+        let done = false;
+        // Assigned once listeners are wired — set to a real cleanup below
+        // so the pre-wire window is never reachable (finish can only fire
+        // after the listeners/timer exist).
+        let cleanup: () => void = () => undefined;
+        const finish = () => {
+          if (done) return;
+          done = true;
+          cleanup();
+          resolve();
+        };
+        const fail = () => {
+          if (done) return;
+          done = true;
+          cleanup();
+          reject(createSwitchTimeoutError(prev.roomId));
+        };
+
+        const onMemberships = (_old: CallMembership[], next: CallMembership[]): void => {
+          if (!selfPresent(next)) finish();
+        };
+        const onHangupAction = (): void => finish();
+
+        session.on(MatrixRTCSessionEvent.MembershipsChanged, onMemberships);
+        prev.call.on('action:im.vector.hangup', onHangupAction);
+        const timer = setTimeout(fail, SWITCH_LEAVE_TIMEOUT_MS);
+
+        cleanup = () => {
+          session.off(MatrixRTCSessionEvent.MembershipsChanged, onMemberships);
+          prev.call.off('action:im.vector.hangup', onHangupAction);
+          clearTimeout(timer);
+        };
+
+        prev.hangup().catch((err: unknown) => {
+          // eslint-disable-next-line no-console
+          console.warn('[dm-call] hangup transport fail (barrier still armed)', err);
+        });
+      });
+    },
+    [mx]
+  );
+
+  const doSwitchOrStart = useCallback(
+    async (roomId: string): Promise<void> => {
+      const room = mx.getRoom(roomId);
+      if (!room) {
+        // eslint-disable-next-line no-console
+        console.warn('[dm-call] room not found', roomId);
+        return;
+      }
+
+      const prev = store.get(callEmbedAtom);
+      if (prev?.roomId === roomId) return;
+
+      const container = callEmbedRef.current;
+      if (!container) {
+        throw new Error('Failed to start call, No embed container element found!');
+      }
+
+      if (prev) {
+        await waitLeave(prev);
+        prev.dispose();
+      }
+
+      const embed = createCallEmbed(mx, room, true, theme.kind, container, callPref, true);
+      store.set(callEmbedAtom, embed);
+    },
+    [mx, store, callEmbedRef, callPref, theme, waitLeave]
+  );
+
+  return useCallback(
+    (roomId: string): Promise<void> => {
+      const enter = (): Promise<void> => {
+        if (inFlightRef.current) {
+          return inFlightRef.current.then(enter, enter);
+        }
+        const task = doSwitchOrStart(roomId);
+        const tracked: Promise<void> = task.finally(() => {
+          if (inFlightRef.current === tracked) inFlightRef.current = undefined;
+        });
+        inFlightRef.current = tracked;
+        return tracked;
+      };
+      return enter();
+    },
+    [doSwitchOrStart]
+  );
+};

src/app/pages/IncomingCallStripRenderer.tsx

@@ -3,11 +3,11 @@
 // Mounted in Router.tsx inside `CallEmbedProvider`, rendered right before
 // `CallStatusRenderer` so the strip stacks above the in-call pill.
 //
-// On native Android the OS CallStyle notification (see
+// IncomingCallStripRenderer is platform-agnostic: if JS knows about an incoming
-// VojoFirebaseMessagingService) owns the incoming-call UX end-to-end: heads-up,
+// ring, we render the in-app strip. On Android the native FCM service decides
-// ringtone, Answer/Decline buttons, full-screen wakeup. Rendering the in-app
+// independently whether to surface a system CallStyle notification; when the
-// strip in parallel just duplicates UI and plays a second ringtone on top of
+// app is foregrounded it now suppresses that banner, so this renderer no longer
-// the system one — so the renderer is a no-op on native.
+// needs to mirror native foreground policy in JS.
 //
 // KNOWN GAP §5.17: if the browser blocks `audio.play()` (cold page load, no
 // user gesture yet), the ring is silent — strip is still visible but user may
@@ -20,7 +20,6 @@ import { Box } from 'folds';
 import { incomingCallsAtom } from '../state/incomingCalls';
 import { useMatrixClient } from '../hooks/useMatrixClient';
 import { IncomingCallStrip } from '../features/call-status';
-import { isNativePlatform } from '../utils/capacitor';
 // eslint-disable-next-line import/no-relative-packages
 import RingSoundOgg from '../../../public/sound/ring.ogg';
 // eslint-disable-next-line import/no-relative-packages
@@ -32,12 +31,11 @@ export function IncomingCallStripRenderer() {
   const audioRef = useRef<HTMLAudioElement>(null);
 
   const hasIncoming = incoming.size > 0;
-  const suppress = isNativePlatform();
 
   useEffect(() => {
     const audio = audioRef.current;
     if (!audio) return;
-    if (hasIncoming && !suppress) {
+    if (hasIncoming) {
       audio.currentTime = 0;
       audio.play().catch(() => {
         // autoplay blocked — strip UI still visible
@@ -46,9 +44,7 @@ export function IncomingCallStripRenderer() {
       audio.pause();
       audio.currentTime = 0;
     }
-  }, [hasIncoming, suppress]);
+  }, [hasIncoming]);
-
-  if (suppress) return null;
 
   const entries = Array.from(incoming.values());
 

src/app/plugins/call/CallEmbed.ts

@@ -29,6 +29,8 @@ import { CallControlState } from './CallControlState';
 export class CallEmbed {
   private mx: MatrixClient;
 
+  private disposed = false;
+
   public readonly call: ClientWidgetApi;
 
   public readonly iframe: HTMLIFrameElement;
@@ -242,6 +244,9 @@ export class CallEmbed {
    * @param opts
    */
   public dispose(): void {
+    if (this.disposed) return;
+    this.disposed = true;
+
     this.disposables.forEach((disposable) => {
       disposable();
     });

src/app/state/pendingCallAction.ts

@@ -3,9 +3,9 @@ import { atom } from 'jotai';
 // Bridge between the native Capacitor push-action listener (which fires outside
 // any React render context) and the in-app call flow. The listener sets the
 // atom; usePendingCallActionConsumer — mounted inside CallEmbedProvider — reads
-// it and triggers useDmCallStart / mx.sendRtcDecline.
+// it and triggers switch-or-start / mx.sendRtcDecline.
 export type PendingCallAction =
-  | { kind: 'answer'; roomId: string }
+  | { kind: 'answer'; roomId: string; notifEventId?: string }
   | { kind: 'decline'; roomId: string; notifEventId: string };
 
 export const pendingCallActionAtom = atom<PendingCallAction | undefined>(undefined);