Merge pull request #3742 from element-hq/toger5/backport-robin/local-transport

[backport] Logically separate the advertised transport from the active transport

.github/workflows/build-element-call.yaml

@@ -7,7 +7,7 @@ on:
         type: string
       package:
         type: string # This would ideally be a `choice` type, but that isn't supported yet
-        description: The package type to be built. Must be one of 'full' or 'embedded'
+        description: The package type to be built. Must be one of 'full', 'embedded', or 'sdk'
         required: true
       build_mode:
         type: string # This would ideally be a `choice` type, but that isn't supported yet

.github/workflows/build.yaml

@@ -69,3 +69,17 @@ jobs:
       SENTRY_URL: ${{ secrets.SENTRY_URL }}
       SENTRY_AUTH_TOKEN: ${{ secrets.SENTRY_AUTH_TOKEN }}
       CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
+
+  build_sdk_element_call:
+    # Use the embedded package vite build
+    uses: ./.github/workflows/build-element-call.yaml
+    with:
+      package: sdk
+      vite_app_version: ${{ github.event.release.tag_name || github.sha }}
+      build_mode: ${{ github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'development build') && 'development' || 'production' }}
+    secrets:
+      SENTRY_ORG: ${{ secrets.SENTRY_ORG }}
+      SENTRY_PROJECT: ${{ secrets.SENTRY_PROJECT }}
+      SENTRY_URL: ${{ secrets.SENTRY_URL }}
+      SENTRY_AUTH_TOKEN: ${{ secrets.SENTRY_AUTH_TOKEN }}
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

.github/workflows/deploy-to-netlify.yaml

@@ -14,6 +14,10 @@ on:
       deployment_ref:
         required: true
         type: string
+      package:
+        required: true
+        type: string
+        description: Which package to deploy - 'full', 'embedded', or 'sdk'
       artifact_run_id:
         required: false
         type: string
@@ -50,7 +54,7 @@ jobs:
         with:
           github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
           run-id: ${{ inputs.artifact_run_id }}
-          name: build-output-full
+          name: build-output-${{ inputs.package }}
           path: webapp
 
       - name: Add redirects file
@@ -58,15 +62,17 @@ jobs:
         run: curl -s https://raw.githubusercontent.com/element-hq/element-call/main/config/netlify_redirects > webapp/_redirects
 
       - name: Add config file
-        run: curl -s "https://raw.githubusercontent.com/${{ inputs.pr_head_full_name }}/${{ inputs.pr_head_ref }}/config/config_netlify_preview.json" > webapp/config.json
-
+        run: |
+          if [ "${{ inputs.package }}" = "full" ]; then
+            curl -s "https://raw.githubusercontent.com/${{ inputs.pr_head_full_name }}/${{ inputs.pr_head_ref }}/config/config_netlify_preview_sdk.json" > webapp/config.json
+          fi
       - name: ☁️ Deploy to Netlify
         id: netlify
         uses: nwtgck/actions-netlify@4cbaf4c08f1a7bfa537d6113472ef4424e4eb654 # v3.0
         with:
           publish-dir: webapp
           deploy-message: "Deploy from GitHub Actions"
-          alias: pr${{ inputs.pr_number }}
+          alias: ${{ inputs.package == 'sdk' && format('pr{0}-sdk', inputs.pr_number) || format('pr{0}', inputs.pr_number) }}
         env:
           NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}
           NETLIFY_SITE_ID: ${{ secrets.NETLIFY_SITE_ID }}

.github/workflows/pr-deploy.yaml

@@ -20,7 +20,7 @@ jobs:
           owner: ${{ github.event.workflow_run.head_repository.owner.login }}
           branch: ${{ github.event.workflow_run.head_branch }}
 
-  netlify:
+  netlify-full:
     needs: prdetails
     permissions:
       deployments: write
@@ -31,6 +31,24 @@ jobs:
       pr_head_full_name: ${{ github.event.workflow_run.head_repository.full_name }}
       pr_head_ref: ${{ needs.prdetails.outputs.pr_data_json && fromJSON(needs.prdetails.outputs.pr_data_json).head.ref }}
       deployment_ref: ${{ needs.prdetails.outputs.pr_data_json && fromJSON(needs.prdetails.outputs.pr_data_json).head.sha || github.ref || github.head_ref }}
+      package: full
+    secrets:
+      ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
+      NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}
+      NETLIFY_SITE_ID: ${{ secrets.NETLIFY_SITE_ID }}
+
+  netlify-sdk:
+    needs: prdetails
+    permissions:
+      deployments: write
+    uses: ./.github/workflows/deploy-to-netlify.yaml
+    with:
+      artifact_run_id: ${{ github.event.workflow_run.id || github.run_id }}
+      pr_number: ${{ needs.prdetails.outputs.pr_number }}
+      pr_head_full_name: ${{ github.event.workflow_run.head_repository.full_name }}
+      pr_head_ref: ${{ needs.prdetails.outputs.pr_data_json && fromJSON(needs.prdetails.outputs.pr_data_json).head.ref }}
+      deployment_ref: ${{ needs.prdetails.outputs.pr_data_json && fromJSON(needs.prdetails.outputs.pr_data_json).head.sha || github.ref || github.head_ref }}
+      package: sdk
     secrets:
       ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
       NETLIFY_AUTH_TOKEN: ${{ secrets.NETLIFY_AUTH_TOKEN }}

package.json

@@ -13,8 +13,9 @@
     "build:embedded": "yarn build:full --config vite-embedded.config.js",
     "build:embedded:production": "yarn build:embedded",
     "build:embedded:development": "yarn build:embedded --mode development",
-    "build:sdk": "yarn build:full --config vite-sdk.config.js",
     "build:sdk:development": "yarn build:sdk --mode development",
+    "build:sdk": "yarn build:full --config vite-sdk.config.js",
+    "build:sdk:production": "yarn build:sdk",
     "serve": "vite preview",
     "prettier:check": "prettier -c .",
     "prettier:format": "prettier -w .",
@@ -104,7 +105,7 @@
     "livekit-client": "^2.13.0",
     "lodash-es": "^4.17.21",
     "loglevel": "^1.9.1",
-    "matrix-js-sdk": "matrix-org/matrix-js-sdk#develop",
+    "matrix-js-sdk": "matrix-org/matrix-js-sdk#6e3efef0c5f660df47cf00874927dec1c75cc3cf",
     "matrix-widget-api": "^1.16.1",
     "node-stdlib-browser": "^1.3.1",
     "normalize.css": "^8.0.1",

sdk/README.md

@@ -1,4 +1,4 @@
-# SDK mode
+# SDK mode (EXPERIMENTAL)
 
 EC can be build in sdk mode. This will result in a compiled js file that can be imported in very simple webapps.
 

sdk/helper.ts

@@ -12,15 +12,12 @@ Please see LICENSE in the repository root for full details.
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { scan } from "rxjs";
 
-import { widget as _widget } from "../src/widget";
+import { type WidgetHelpers } from "../src/widget";
 import { type LivekitRoomItem } from "../src/state/CallViewModel/CallViewModel";
 
 export const logger = rootLogger.getChild("[MatrixRTCSdk]");
 
-if (!_widget) throw Error("No widget. This webapp can only start as a widget");
-export const widget = _widget;
-
-export const tryMakeSticky = (): void => {
+export const tryMakeSticky = (widget: WidgetHelpers): void => {
   logger.info("try making sticky MatrixRTCSdk");
   void widget.api
     .setAlwaysOnScreen(true)

sdk/main.ts

@@ -6,6 +6,8 @@ Please see LICENSE in the repository root for full details.
 */
 
 /**
+ * EXPERIMENTAL
+ *
  * This file is the entrypoint for the sdk build of element call: `yarn build:sdk`
  * use in widgets.
  * It exposes the `createMatrixRTCSdk` which creates the `MatrixRTCSdk` interface (see below) that
@@ -30,8 +32,8 @@ import {
 } from "rxjs";
 import {
   type CallMembership,
-  MatrixRTCSession,
   MatrixRTCSessionEvent,
+  MatrixRTCSessionManager,
 } from "matrix-js-sdk/lib/matrixrtc";
 import {
   type Room as LivekitRoom,
@@ -50,14 +52,12 @@ import { getUrlParams } from "../src/UrlParams";
 import { MuteStates } from "../src/state/MuteStates";
 import { MediaDevices } from "../src/state/MediaDevices";
 import { E2eeType } from "../src/e2ee/e2eeType";
+import { currentAndPrev, logger, TEXT_LK_TOPIC, tryMakeSticky } from "./helper";
 import {
-  currentAndPrev,
-  logger,
-  TEXT_LK_TOPIC,
-  tryMakeSticky,
-  widget,
-} from "./helper";
-import { ElementWidgetActions, initializeWidget } from "../src/widget";
+  ElementWidgetActions,
+  widget as _widget,
+  initializeWidget,
+} from "../src/widget";
 import { type Connection } from "../src/state/CallViewModel/remoteMembers/Connection";
 
 interface MatrixRTCSdk {
@@ -68,7 +68,13 @@ interface MatrixRTCSdk {
   join: () => void;
   /** @throws on leave errors */
   leave: () => void;
-  data$: Observable<{ sender: string; data: string }>;
+  /**
+   * Ends the rtc sdk. This will unsubscribe any event listeners. And end the associated scope.
+   * No updates can be received from the rtc sdk. The sdk cannot be restarted after.
+   * A new sdk needs to be created via createMatrixRTCSdk.
+   */
+  stop: () => void;
+  data$: Observable<{ rtcBackendIdentity: string; data: string }>;
   /**
    * flattened list of members
    */
@@ -79,32 +85,54 @@ interface MatrixRTCSdk {
       participant: LocalParticipant | RemoteParticipant | null;
     }[]
   >;
+  /**
+   * flattened local members
+   */
+  localMember$: Behavior<{
+    connection: Connection | null;
+    membership: CallMembership;
+    participant: LocalParticipant | null;
+  } | null>;
   /** Use the LocalMemberConnectionState returned from `join` for a more detailed connection state  */
   connected$: Behavior<boolean>;
   sendData?: (data: unknown) => Promise<void>;
+  sendRoomMessage?: (message: string) => Promise<void>;
 }
 
 export async function createMatrixRTCSdk(
   application: string = "m.call",
   id: string = "",
+  sticky: boolean = false,
 ): Promise<MatrixRTCSdk> {
-  initializeWidget();
+  const scope = new ObservableScope();
+
+  // widget client
+  initializeWidget(application, true);
+  const widget = _widget;
+  if (!widget) throw Error("No widget. This webapp can only start as a widget");
   const client = await widget.client;
   logger.info("client created");
-  const scope = new ObservableScope();
+
+  // url params
   const { roomId } = getUrlParams();
   if (roomId === null) throw Error("could not get roomId from url params");
-
   const room = client.getRoom(roomId);
   if (room === null) throw Error("could not get room from client");
 
+  // rtc session
+  const slot = { application, id };
+  const rtcSessionManager = new MatrixRTCSessionManager(logger, client, slot);
+  rtcSessionManager.start();
+  const rtcSession = rtcSessionManager.getRoomSession(room);
+
+  // media devices
   const mediaDevices = new MediaDevices(scope);
   const muteStates = new MuteStates(scope, mediaDevices, {
-    audioEnabled: true,
-    videoEnabled: true,
+    audioEnabled: false,
+    videoEnabled: false,
   });
-  const slot = { application, id };
-  const rtcSession = new MatrixRTCSession(client, room, slot);
+
+  // call view model
   const callViewModel = createCallViewModel$(
     scope,
     rtcSession,
@@ -117,8 +145,9 @@ export async function createMatrixRTCSdk(
     constant({ supported: false, processor: undefined }),
   );
   logger.info("CallViewModelCreated");
+
   // create data listener
-  const data$ = new Subject<{ sender: string; data: string }>();
+  const data$ = new Subject<{ rtcBackendIdentity: string; data: string }>();
 
   const lkTextStreamHandlerFunction = async (
     reader: TextStreamReader,
@@ -140,7 +169,7 @@ export async function createMatrixRTCSdk(
     if (participants && participants.includes(participantInfo.identity)) {
       const text = await reader.readAll();
       logger.info(`Received text: ${text}`);
-      data$.next({ sender: participantInfo.identity, data: text });
+      data$.next({ rtcBackendIdentity: participantInfo.identity, data: text });
     } else {
       logger.warn(
         "Received text from unknown participant",
@@ -230,6 +259,16 @@ export async function createMatrixRTCSdk(
     }
   };
 
+  const sendRoomMessage = async (message: string): Promise<void> => {
+    const messageString = JSON.stringify(message);
+    logger.info("try sending to room: ", messageString);
+    try {
+      await client.sendTextMessage(room.roomId, message);
+    } catch (e) {
+      logger.error("failed sending to room: ", messageString, e);
+    }
+  };
+
   // after hangup gets called
   const leaveSubs = callViewModel.leave$.subscribe(() => {
     const scheduleWidgetCloseOnLeave = async (): Promise<void> => {
@@ -257,9 +296,6 @@ export async function createMatrixRTCSdk(
 
     // schedule close first and then leave (scope.end)
     void scheduleWidgetCloseOnLeave();
-
-    // actual hangup (ending scope will send the leave event.. its kinda odd. since you might end up closing the widget too fast)
-    scope.end();
   });
 
   logger.info("createMatrixRTCSdk done");
@@ -267,15 +303,40 @@ export async function createMatrixRTCSdk(
   return {
     join: (): void => {
       // first lets try making the widget sticky
-      tryMakeSticky();
+      if (sticky) tryMakeSticky(widget);
       callViewModel.join();
     },
     leave: (): void => {
-      callViewModel.hangup();
+      callViewModel.leave();
+    },
+    stop: (): void => {
       leaveSubs.unsubscribe();
       livekitRoomItemsSub.unsubscribe();
+      scope.end();
     },
     data$,
+    localMember$: scope.behavior(
+      callViewModel.localMatrixLivekitMember$.pipe(
+        tap((member) =>
+          logger.info("localMatrixLivekitMember$ next: ", member),
+        ),
+        switchMap((member) => {
+          if (member === null) return of(null);
+          return combineLatest([
+            member.connection$,
+            member.membership$,
+            member.participant.value$,
+          ]).pipe(
+            map(([connection, membership, participant]) => ({
+              connection,
+              membership,
+              participant,
+            })),
+          );
+        }),
+        tap((member) => logger.info("localMember$ next: ", member)),
+      ),
+    ),
     connected$: callViewModel.connected$,
     members$: scope.behavior(
       callViewModel.matrixLivekitMembers$.pipe(
@@ -302,5 +363,6 @@ export async function createMatrixRTCSdk(
       [],
     ),
     sendData,
+    sendRoomMessage,
   };
 }

src/livekit/openIDSFU.ts

@@ -78,8 +78,8 @@ export type OpenIDClientParts = Pick<
  * @param membership Our own membership identity parts used to send to jwt service.
  * @param serviceUrl The URL of the livekit SFU service
  * @param roomId The room id used in the jwt request. This is NOT the livekit_alias. The jwt service will provide the alias. It maps matrix room ids <-> Livekit aliases.
- * @param opts Additional options to modify which endpoint with which data will be used to aquire the jwt token.
- * @param opts.forceJwtEndpoint This will use the old jwt endpoint which will create the rtc backend identity based on string concatination
+ * @param opts Additional options to modify which endpoint with which data will be used to acquire the jwt token.
+ * @param opts.forceJwtEndpoint This will use the old jwt endpoint which will create the rtc backend identity based on string concatenation
  * instead of a hash.
  * This function by default uses whatever is possible with the current jwt service installed next to the SFU.
  * For remote connections this does not matter, since we will not publish there we can rely on the newest option.

src/settings/rageshake.test.ts

@@ -0,0 +1,34 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { expect, it } from "vitest";
+
+import { init as initRageshake } from "./rageshake";
+
+it("Logger should not crash if JSON.stringify fails", async () => {
+  // JSON.stringify can throw. We want to make sure that the logger can handle this gracefully.
+  await initRageshake();
+
+  const bigIntObj = { n: 1n };
+  const notStringifiable = {
+    bigIntObj,
+  };
+  // @ts-expect-error - we want to create an object that cannot be stringified
+  notStringifiable.foo = notStringifiable; // circular reference
+
+  // ensure this cannot be stringified
+  expect(() => JSON.stringify(notStringifiable)).toThrow();
+
+  expect(() =>
+    global.mx_rage_logger.log(
+      1,
+      "test",
+      "This is a test message",
+      notStringifiable,
+    ),
+  ).not.toThrow();
+});

src/settings/rageshake.ts

@@ -75,7 +75,14 @@ class ConsoleLogger extends EventEmitter {
       } else if (arg instanceof Error) {
         return arg.message + (arg.stack ? `\n${arg.stack}` : "");
       } else if (typeof arg === "object") {
-        return JSON.stringify(arg, getCircularReplacer());
+        try {
+          return JSON.stringify(arg, getCircularReplacer());
+        } catch {
+          // Stringify can fail if the object has circular references or if
+          // there is a bigInt.
+          // Did happen even with our `getCircularReplacer`. In this case, just log
+          return "<$ failed to serialize object $>";
+        }
       } else {
         return arg;
       }

src/state/CallViewModel/CallNotificationLifecycle.test.ts

@@ -5,10 +5,6 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import {
-  type ICallNotifyContent,
-  type IRTCNotificationContent,
-} from "matrix-js-sdk/lib/matrixrtc";
 import { describe, it } from "vitest";
 import {
   EventType,
@@ -25,23 +21,23 @@ import {
   localRtcMember,
 } from "../../utils/test-fixtures";
 import {
+  type CallNotificationWrapper,
   createCallNotificationLifecycle$,
   type Props as CallNotificationLifecycleProps,
 } from "./CallNotificationLifecycle";
 import { trackEpoch } from "../ObservableScope";
 
-const mockLegacyRingEvent = {} as { event_id: string } & ICallNotifyContent;
 function mockRingEvent(
   eventId: string,
   lifetimeMs: number | undefined,
   sender = local.userId,
-): { event_id: string } & IRTCNotificationContent {
+): CallNotificationWrapper {
   return {
     event_id: eventId,
     ...(lifetimeMs === undefined ? {} : { lifetime: lifetimeMs }),
     notification_type: "ring",
     sender,
-  } as unknown as { event_id: string } & IRTCNotificationContent;
+  } as unknown as CallNotificationWrapper;
 }
 
 describe("waitForCallPickup$", () => {
@@ -54,7 +50,7 @@ describe("waitForCallPickup$", () => {
           behavior("a", { a: [] }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$notif1", 30), mockLegacyRingEvent],
+          a: mockRingEvent("$notif1", 30),
         }),
         receivedDecline$: hot(""),
         options: {
@@ -86,7 +82,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("5ms a", {
-          a: [mockRingEvent("$notif2", 100), mockLegacyRingEvent],
+          a: mockRingEvent("$notif2", 100),
         }),
         receivedDecline$: hot(""),
         options: {
@@ -115,7 +111,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("20ms a", {
-          a: [mockRingEvent("$notif2", 50), mockLegacyRingEvent],
+          a: mockRingEvent("$notif2", 50),
         }),
         receivedDecline$: hot(""),
         options: {
@@ -142,7 +138,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$notif2", undefined), mockLegacyRingEvent],
+          a: mockRingEvent("$notif2", undefined),
         }),
         receivedDecline$: hot(""),
         options: {
@@ -171,7 +167,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$notif5", 30), mockLegacyRingEvent],
+          a: mockRingEvent("$notif5", 30),
         }),
         receivedDecline$: hot(""),
         options: {
@@ -210,7 +206,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$decl1", 50), mockLegacyRingEvent],
+          a: mockRingEvent("$decl1", 50),
         }),
         receivedDecline$: hot("40ms d", {
           d: [
@@ -254,7 +250,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$decl", 20), mockLegacyRingEvent],
+          a: mockRingEvent("$decl", 20),
         }),
         receivedDecline$: hot("40ms d", {
           d: [
@@ -305,7 +301,7 @@ describe("waitForCallPickup$", () => {
           }).pipe(trackEpoch()),
         ),
         sentCallNotification$: hot("10ms a", {
-          a: [mockRingEvent("$right", 50), mockLegacyRingEvent],
+          a: mockRingEvent("$right", 50),
         }),
         receivedDecline$: hot("20ms d", {
           d: [

src/state/CallViewModel/CallNotificationLifecycle.ts

@@ -7,9 +7,9 @@ Please see LICENSE in the repository root for full details.
 
 import {
   type CallMembership,
+  type IRTCNotificationContent,
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
-  type MatrixRTCSessionEventHandlerMap,
 } from "matrix-js-sdk/lib/matrixrtc";
 import {
   combineLatest,
@@ -38,6 +38,7 @@ import {
 
 import { type Behavior } from "../Behavior";
 import { type Epoch, mapEpoch, type ObservableScope } from "../ObservableScope";
+
 export type AutoLeaveReason = "allOthersLeft" | "timeout" | "decline";
 export type CallPickupState =
   | "unknown"
@@ -46,9 +47,11 @@ export type CallPickupState =
   | "decline"
   | "success"
   | null;
-export type CallNotificationWrapper = Parameters<
-  MatrixRTCSessionEventHandlerMap[MatrixRTCSessionEvent.DidSendCallNotification]
->;
+
+export type CallNotificationWrapper = {
+  event_id: string;
+} & IRTCNotificationContent;
+
 export function createSentCallNotification$(
   scope: ObservableScope,
   matrixRTCSession: MatrixRTCSession,
@@ -80,6 +83,7 @@ export interface Props {
   options: { waitForCallPickup?: boolean; autoLeaveWhenOthersLeft?: boolean };
   localUser: { deviceId: string; userId: string };
 }
+
 /**
  * @returns two observables:
  * `callPickupState$` The current call pickup state of the call.
@@ -140,12 +144,12 @@ export function createCallNotificationLifecycle$({
     scope.behavior(
       sentCallNotification$.pipe(
         filter(
-          (newAndLegacyEvents) =>
+          (notificationEventArgs: CallNotificationWrapper | null) =>
             // only care about new events (legacy do not have decline pattern)
-            newAndLegacyEvents?.[0].notification_type === "ring",
+            notificationEventArgs?.notification_type === "ring",
         ),
         map((e) => e as CallNotificationWrapper),
-        switchMap(([notificationEvent]) => {
+        switchMap((notificationEvent) => {
           const lifetimeMs = notificationEvent?.lifetime ?? 0;
           return concat(
             lifetimeMs === 0

src/state/CallViewModel/CallViewModel.test.ts

@@ -29,7 +29,6 @@ import {
   Status,
   type CallMembership,
   type IRTCNotificationContent,
-  type ICallNotifyContent,
   MatrixRTCSessionEvent,
   type LivekitTransport,
 } from "matrix-js-sdk/lib/matrixrtc";
@@ -232,10 +231,6 @@ function mockRingEvent(
   } as unknown as { event_id: string } & IRTCNotificationContent;
 }
 
-// The app doesn't really care about the content of these legacy events, we just
-// need a value to fill in for them when emitting notifications
-const mockLegacyRingEvent = {} as { event_id: string } & ICallNotifyContent;
-
 describe.each([
   [MatrixRTCMode.Legacy],
   [MatrixRTCMode.Compatibility],
@@ -1109,7 +1104,6 @@ describe.each([
                 rtcSession.emit(
                   MatrixRTCSessionEvent.DidSendCallNotification,
                   mockRingEvent("$notif1", 30),
-                  mockLegacyRingEvent,
                 );
               },
             });
@@ -1151,7 +1145,6 @@ describe.each([
                 rtcSession.emit(
                   MatrixRTCSessionEvent.DidSendCallNotification,
                   mockRingEvent("$notif2", 100),
-                  mockLegacyRingEvent,
                 );
               },
               d: () => {

src/state/CallViewModel/CallViewModel.ts

@@ -42,7 +42,7 @@ import {
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import {
   MembershipManagerEvent,
-  type LivekitTransport,
+  type LivekitTransportConfig,
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { type IWidgetApiRequest } from "matrix-widget-api";
@@ -60,6 +60,7 @@ import {
 import {
   accumulate,
   filterBehavior,
+  generateItem,
   generateItems,
   pauseWhen,
 } from "../../utils/observable";
@@ -103,7 +104,7 @@ import {
   type SpotlightPortraitLayoutMedia,
 } from "../layout-types.ts";
 import { ElementCallError, UnknownCallError } from "../../utils/errors.ts";
-import { type ObservableScope } from "../ObservableScope.ts";
+import { type Epoch, type ObservableScope } from "../ObservableScope.ts";
 import { createHomeserverConnected$ } from "./localMember/HomeserverConnected.ts";
 import {
   createLocalMembership$,
@@ -217,15 +218,23 @@ export interface CallViewModel {
     "unknown" | "ringing" | "timeout" | "decline" | "success" | null
   >;
   /** Observable that emits when the user should leave the call (hangup pressed, widget action, error).
-   * THIS DOES NOT LEAVE THE CALL YET. The only way to leave the call (send the hangup event) is by ending the scope.
+   * THIS DOES NOT LEAVE THE CALL YET. The only way to leave the call (send the hangup event) is
+   *  - by ending the scope
+   *  - or calling requestDisconnect
+   *
+   * TODO: it seems more reasonable to add a leave() method (that calls requestDisconnect) that will then update leave$ and remove the hangup pattern
    */
   leave$: Observable<"user" | AutoLeaveReason>;
-  /** Call to initiate hangup. Use in conbination with reconnectino state track the async hangup process. */
+  /** Call to initiate hangup. Use in conbination with reconnection state track the async hangup process. */
   hangup: () => void;
 
   // joining
   join: () => void;
 
+  /**
+   * calls requestDisconnect. The async leave state can than be observed via connected$
+   */
+  leave: () => void;
   // screen sharing
   /**
    * Callback to toggle screen sharing. If null, screen sharing is not possible.
@@ -436,38 +445,42 @@ export function createCallViewModel$(
     memberId: uuidv4(),
   };
 
-  const localTransport$ = createLocalTransport$({
-    scope: scope,
-    memberships$: memberships$,
-    ownMembershipIdentity,
-    client,
-    delayId$: scope.behavior(
-      (
-        fromEvent(
-          matrixRTCSession,
-          MembershipManagerEvent.DelayIdChanged,
-          // The type of reemitted event includes the original emitted as the second arg.
-        ) as Observable<[string | undefined, IMembershipManager]>
-      ).pipe(map(([delayId]) => delayId ?? null)),
-      matrixRTCSession.delayId ?? null,
-    ),
-    roomId: matrixRoom.roomId,
-    forceJwtEndpoint$: scope.behavior(
-      matrixRTCMode$.pipe(
-        map((v) =>
-          v === MatrixRTCMode.Matrix_2_0
-            ? JwtEndpointVersion.Matrix_2_0
-            : JwtEndpointVersion.Legacy,
-        ),
+  const localTransport$ = scope.behavior(
+    matrixRTCMode$.pipe(
+      generateItem(
+        "CallViewModel localTransport$",
+        // Re-create LocalTransport whenever the mode changes
+        (mode) => ({ keys: [mode], data: undefined }),
+        (scope, _data$, mode) =>
+          createLocalTransport$({
+            scope: scope,
+            memberships$: memberships$,
+            ownMembershipIdentity,
+            client,
+            delayId$: scope.behavior(
+              (
+                fromEvent(
+                  matrixRTCSession,
+                  MembershipManagerEvent.DelayIdChanged,
+                  // The type of reemitted event includes the original emitted as the second arg.
+                ) as Observable<[string | undefined, IMembershipManager]>
+              ).pipe(map(([delayId]) => delayId ?? null)),
+              matrixRTCSession.delayId ?? null,
+            ),
+            roomId: matrixRoom.roomId,
+            forceJwtEndpoint:
+              mode === MatrixRTCMode.Matrix_2_0
+                ? JwtEndpointVersion.Matrix_2_0
+                : JwtEndpointVersion.Legacy,
+            useOldestMember: mode === MatrixRTCMode.Legacy,
+          }),
       ),
     ),
-    useOldestMember$: scope.behavior(
-      matrixRTCMode$.pipe(map((v) => v === MatrixRTCMode.Legacy)),
-    ),
-  });
+  );
 
   const connectionFactory = new ECConnectionFactory(
     client,
+    matrixRoom.roomId,
     mediaDevices,
     trackProcessorState$,
     livekitKeyProvider,
@@ -482,6 +495,7 @@ export function createCallViewModel$(
     connectionFactory: connectionFactory,
     localTransport$: scope.behavior(
       localTransport$.pipe(
+        switchMap((t) => t.active$),
         catchError((e: unknown) => {
           logger.info(
             "could not pass local transport to createConnectionManager$. localTransport$ threw an error",
@@ -496,12 +510,13 @@ export function createCallViewModel$(
     ownMembershipIdentity,
   });
 
-  const matrixLivekitMembers$ = createMatrixLivekitMembers$({
-    scope: scope,
-    membershipsWithTransport$:
-      membershipsAndTransports.membershipsWithTransport$,
-    connectionManager: connectionManager,
-  });
+  const matrixLivekitMembers$: Behavior<Epoch<RemoteMatrixLivekitMember[]>> =
+    createMatrixLivekitMembers$({
+      scope: scope,
+      membershipsWithTransport$:
+        membershipsAndTransports.membershipsWithTransport$,
+      connectionManager: connectionManager,
+    });
 
   const connectOptions$ = scope.behavior(
     matrixRTCMode$.pipe(
@@ -514,14 +529,14 @@ export function createCallViewModel$(
   );
 
   const localMembership = createLocalMembership$({
-    scope: scope,
+    scope,
     homeserverConnected: createHomeserverConnected$(
       scope,
       client,
       matrixRTCSession,
     ),
-    muteStates: muteStates,
-    joinMatrixRTC: (transport: LivekitTransport) => {
+    muteStates,
+    joinMatrixRTC: (transport: LivekitTransportConfig) => {
       return enterRTCSession(
         matrixRTCSession,
         ownMembershipIdentity,
@@ -540,9 +555,11 @@ export function createCallViewModel$(
         ),
       );
     },
-    connectionManager: connectionManager,
-    matrixRTCSession: matrixRTCSession,
-    localTransport$: localTransport$,
+    connectionManager,
+    matrixRTCSession,
+    localTransport$: scope.behavior(
+      localTransport$.pipe(switchMap((t) => t.advertised$)),
+    ),
     logger: logger.getChild(`[${Date.now()}]`),
   });
 
@@ -1494,6 +1511,7 @@ export function createCallViewModel$(
     leave$: leave$,
     hangup: (): void => userHangup$.next(),
     join: localMembership.requestJoinAndPublish,
+    leave: localMembership.requestDisconnect,
     toggleScreenSharing: toggleScreenSharing,
     sharingScreen$: sharingScreen$,
 
@@ -1543,7 +1561,15 @@ export function createCallViewModel$(
       matrixLivekitMembers$.pipe(
         map((members) => members.value),
         tap((v) => {
-          logger.debug("matrixLivekitMembers$ updated (exported)", v);
+          const listForLogs = v
+            .map(
+              (m) =>
+                m.membership$.value.userId + "|" + m.membership$.value.deviceId,
+            )
+            .join(",");
+          logger.debug(
+            `matrixLivekitMembers$ updated (exported) [${listForLogs}]`,
+          );
         }),
       ),
     ),

src/state/CallViewModel/localMember/LocalMember.test.ts

@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.
 
 import {
   Status as RTCMemberStatus,
-  type LivekitTransport,
+  type LivekitTransportConfig,
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { describe, expect, it, vi } from "vitest";
@@ -39,7 +39,6 @@ import { constant } from "../../Behavior";
 import { ConnectionManagerData } from "../remoteMembers/ConnectionManager";
 import { ConnectionState, type Connection } from "../remoteMembers/Connection";
 import { type Publisher } from "./Publisher";
-import { type LocalTransportWithSFUConfig } from "./LocalTransport";
 import { initializeWidget } from "../../../widget";
 
 initializeWidget();
@@ -216,11 +215,10 @@ describe("LocalMembership", () => {
 
   it("throws error on missing RTC config error", () => {
     withTestScheduler(({ scope, hot, expectObservable }) => {
-      const localTransport$ =
-        scope.behavior<null | LocalTransportWithSFUConfig>(
-          hot("1ms #", {}, new MatrixRTCTransportMissingError("domain.com")),
-          null,
-        );
+      const localTransport$ = scope.behavior<null | LivekitTransportConfig>(
+        hot("1ms #", {}, new MatrixRTCTransportMissingError("domain.com")),
+        null,
+      );
 
       // we do not need any connection data since we want to fail before reaching that.
       const mockConnectionManager = {
@@ -279,23 +277,11 @@ describe("LocalMembership", () => {
   });
 
   const aTransport = {
-    transport: {
-      livekit_service_url: "a",
-    } as LivekitTransport,
-    sfuConfig: {
-      url: "sfu-url",
-      jwt: "sfu-token",
-    },
-  } as LocalTransportWithSFUConfig;
+    livekit_service_url: "a",
+  } as LivekitTransportConfig;
   const bTransport = {
-    transport: {
-      livekit_service_url: "b",
-    } as LivekitTransport,
-    sfuConfig: {
-      url: "sfu-url",
-      jwt: "sfu-token",
-    },
-  } as LocalTransportWithSFUConfig;
+    livekit_service_url: "b",
+  } as LivekitTransportConfig;
 
   const connectionTransportAConnected = {
     livekitRoom: mockLivekitRoom({
@@ -305,7 +291,7 @@ describe("LocalMembership", () => {
       } as unknown as LocalParticipant,
     }),
     state$: constant(ConnectionState.LivekitConnected),
-    transport: aTransport.transport,
+    transport: aTransport,
   } as unknown as Connection;
   const connectionTransportAConnecting = {
     ...connectionTransportAConnected,
@@ -314,7 +300,7 @@ describe("LocalMembership", () => {
   } as unknown as Connection;
   const connectionTransportBConnected = {
     state$: constant(ConnectionState.LivekitConnected),
-    transport: bTransport.transport,
+    transport: bTransport,
     livekitRoom: mockLivekitRoom({}),
   } as unknown as Connection;
 
@@ -368,12 +354,8 @@ describe("LocalMembership", () => {
     // stop the first Publisher and let the second one life.
     expect(publishers[0].destroy).toHaveBeenCalled();
     expect(publishers[1].destroy).not.toHaveBeenCalled();
-    expect(publisherFactory.mock.calls[0][0].transport).toBe(
-      aTransport.transport,
-    );
-    expect(publisherFactory.mock.calls[1][0].transport).toBe(
-      bTransport.transport,
-    );
+    expect(publisherFactory.mock.calls[0][0].transport).toBe(aTransport);
+    expect(publisherFactory.mock.calls[1][0].transport).toBe(bTransport);
     scope.end();
     await flushPromises();
     // stop all tracks after ending scopes
@@ -446,8 +428,9 @@ describe("LocalMembership", () => {
     const scope = new ObservableScope();
 
     const connectionManagerData = new ConnectionManagerData();
-    const localTransport$ =
-      new BehaviorSubject<null | LocalTransportWithSFUConfig>(null);
+    const localTransport$ = new BehaviorSubject<null | LivekitTransportConfig>(
+      null,
+    );
     const connectionManagerData$ = new BehaviorSubject(
       new Epoch(connectionManagerData),
     );
@@ -519,7 +502,7 @@ describe("LocalMembership", () => {
     });
 
     (
-      connectionManagerData2.getConnectionForTransport(aTransport.transport)!
+      connectionManagerData2.getConnectionForTransport(aTransport)!
         .state$ as BehaviorSubject<ConnectionState>
     ).next(ConnectionState.LivekitConnected);
     expect(localMembership.localMemberState$.value).toStrictEqual({

src/state/CallViewModel/localMember/LocalMember.ts

@@ -17,6 +17,7 @@ import { observeParticipantEvents } from "@livekit/components-core";
 import {
   Status as RTCSessionStatus,
   type LivekitTransport,
+  type LivekitTransportConfig,
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import {
@@ -61,7 +62,6 @@ import {
 } from "../remoteMembers/Connection.ts";
 import { type HomeserverConnected } from "./HomeserverConnected.ts";
 import { and$ } from "../../../utils/observable.ts";
-import { type LocalTransportWithSFUConfig } from "./LocalTransport.ts";
 
 export enum TransportState {
   /** Not even a transport is available to the LocalMembership */
@@ -125,9 +125,9 @@ interface Props {
   muteStates: MuteStates;
   connectionManager: IConnectionManager;
   createPublisherFactory: (connection: Connection) => Publisher;
-  joinMatrixRTC: (transport: LivekitTransport) => void;
+  joinMatrixRTC: (transport: LivekitTransportConfig) => void;
   homeserverConnected: HomeserverConnected;
-  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
+  localTransport$: Behavior<LivekitTransportConfig | null>;
   matrixRTCSession: Pick<
     MatrixRTCSession,
     "updateCallIntent" | "leaveRoomSession"
@@ -146,7 +146,7 @@ interface Props {
  * @param props.createPublisherFactory Factory to create a publisher once we have a connection.
  * @param props.joinMatrixRTC Callback to join the matrix RTC session once we have a transport.
  * @param props.homeserverConnected The homeserver connected state.
- * @param props.localTransport$ The local transport to use for publishing.
+ * @param props.localTransport$ The transport to advertise in our membership.
  * @param props.logger The logger to use.
  * @param props.muteStates The mute states for video and audio.
  * @param props.matrixRTCSession The matrix RTC session to join.
@@ -236,9 +236,7 @@ export const createLocalMembership$ = ({
           return null;
         }
 
-        return connectionData.getConnectionForTransport(
-          localTransport.transport,
-        );
+        return connectionData.getConnectionForTransport(localTransport);
       }),
       tap((connection) => {
         logger.info(
@@ -548,7 +546,7 @@ export const createLocalMembership$ = ({
       if (!shouldConnect) return;
 
       try {
-        joinMatrixRTC(transport.transport);
+        joinMatrixRTC(transport);
       } catch (error) {
         logger.error("Error entering RTC session", error);
         if (error instanceof Error)
@@ -717,7 +715,7 @@ interface EnterRTCSessionOptions {
 export function enterRTCSession(
   rtcSession: MatrixRTCSession,
   ownMembershipIdentity: CallMembershipIdentityParts,
-  transport: LivekitTransport,
+  transport: LivekitTransportConfig,
   options: EnterRTCSessionOptions,
 ): void {
   const { encryptMedia, matrixRTCMode } = options;
@@ -735,12 +733,26 @@ export function enterRTCSession(
   const multiSFU =
     matrixRTCMode === MatrixRTCMode.Compatibility ||
     matrixRTCMode === MatrixRTCMode.Matrix_2_0;
+
+  // For backwards compatibility with Element Call versions that do not do Matrix 2.0,
+  // we add the livekit alias to the transport.
+  let backwardCompatibleTransport: LivekitTransport | LivekitTransportConfig;
+  if (matrixRTCMode === MatrixRTCMode.Matrix_2_0) {
+    backwardCompatibleTransport = transport;
+  } else {
+    backwardCompatibleTransport = {
+      livekit_alias: rtcSession.room.roomId,
+      ...transport,
+    };
+  }
+
   // Multi-sfu does not need a preferred foci list. just the focus that is actually used.
   // TODO where/how do we track errors originating from the ongoing rtcSession?
+
   rtcSession.joinRTCSession(
     ownMembershipIdentity,
-    multiSFU ? [] : [transport],
-    multiSFU ? transport : undefined,
+    multiSFU ? [] : [backwardCompatibleTransport],
+    multiSFU ? backwardCompatibleTransport : undefined,
     {
       notificationType,
       callIntent,

src/state/CallViewModel/localMember/LocalTransport.test.ts

@@ -13,15 +13,24 @@ import {
   it,
   type MockedObject,
   vi,
+  type MockInstance,
 } from "vitest";
-import { type CallMembership } from "matrix-js-sdk/lib/matrixrtc";
+import {
+  type CallMembership,
+  type LivekitTransportConfig,
+} from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject, lastValueFrom } from "rxjs";
 import fetchMock from "fetch-mock";
 
-import { mockConfig, flushPromises, ownMemberMock } from "../../../utils/test";
+import {
+  mockConfig,
+  flushPromises,
+  ownMemberMock,
+  mockRtcMembership,
+} from "../../../utils/test";
 import { createLocalTransport$, JwtEndpointVersion } from "./LocalTransport";
 import { constant } from "../../Behavior";
-import { Epoch, ObservableScope } from "../../ObservableScope";
+import { Epoch, ObservableScope, trackEpoch } from "../../ObservableScope";
 import {
   MatrixRTCTransportMissingError,
   FailToGetOpenIdToken,
@@ -34,7 +43,7 @@ describe("LocalTransport", () => {
   const openIdResponse: openIDSFU.SFUConfig = {
     url: "https://lk.example.org",
     jwt: testJWTToken,
-    livekitAlias: "!example_room_id",
+    livekitAlias: "Akph4alDMhen",
     livekitIdentity: "@lk_user:ABCDEF",
   };
 
@@ -43,10 +52,10 @@ describe("LocalTransport", () => {
   afterEach(() => scope.end());
 
   it("throws if config is missing", async () => {
-    const localTransport$ = createLocalTransport$({
+    const { advertised$, active$ } = createLocalTransport$({
       scope,
       roomId: "!room:example.org",
-      useOldestMember$: constant(false),
+      useOldestMember: false,
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
         // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -58,14 +67,15 @@ describe("LocalTransport", () => {
         getDeviceId: vi.fn(),
       },
       ownMembershipIdentity: ownMemberMock,
-      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      forceJwtEndpoint: JwtEndpointVersion.Legacy,
       delayId$: constant("delay_id_mock"),
     });
     await flushPromises();
 
-    expect(() => localTransport$.value).toThrow(
+    expect(() => advertised$.value).toThrow(
       new MatrixRTCTransportMissingError(""),
     );
+    expect(() => active$.value).toThrow(new MatrixRTCTransportMissingError(""));
   });
 
   it("throws FailToGetOpenIdToken when OpenID fetch fails", async () => {
@@ -83,10 +93,10 @@ describe("LocalTransport", () => {
     );
     const observations: unknown[] = [];
     const errors: Error[] = [];
-    const localTransport$ = createLocalTransport$({
+    const { advertised$, active$ } = createLocalTransport$({
       scope,
       roomId: "!example_room_id",
-      useOldestMember$: constant(false),
+      useOldestMember: false,
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
         baseUrl: "https://lk.example.org",
@@ -98,10 +108,10 @@ describe("LocalTransport", () => {
         getDeviceId: vi.fn(),
       },
       ownMembershipIdentity: ownMemberMock,
-      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      forceJwtEndpoint: JwtEndpointVersion.Legacy,
       delayId$: constant("delay_id_mock"),
     });
-    localTransport$.subscribe(
+    active$.subscribe(
       (o) => observations.push(o),
       (e) => errors.push(e),
     );
@@ -111,7 +121,8 @@ describe("LocalTransport", () => {
     const expectedError = new FailToGetOpenIdToken(new Error("no openid"));
     expect(observations).toStrictEqual([null]);
     expect(errors).toStrictEqual([expectedError]);
-    expect(() => localTransport$.value).toThrow(expectedError);
+    expect(() => advertised$.value).toThrow(expectedError);
+    expect(() => active$.value).toThrow(expectedError);
   });
 
   it("emits preferred transport after OpenID resolves", async () => {
@@ -126,10 +137,10 @@ describe("LocalTransport", () => {
       openIdResolver.promise,
     );
 
-    const localTransport$ = createLocalTransport$({
+    const { advertised$, active$ } = createLocalTransport$({
       scope,
       roomId: "!room:example.org",
-      useOldestMember$: constant(false),
+      useOldestMember: false,
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
         // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -140,80 +151,152 @@ describe("LocalTransport", () => {
         baseUrl: "https://lk.example.org",
       },
       ownMembershipIdentity: ownMemberMock,
-      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      forceJwtEndpoint: JwtEndpointVersion.Legacy,
       delayId$: constant("delay_id_mock"),
     });
 
     openIdResolver.resolve?.({
       url: "https://lk.example.org",
       jwt: "jwt",
-      livekitAlias: "!room:example.org",
+      livekitAlias: "Akph4alDMhen",
       livekitIdentity: ownMemberMock.userId + ":" + ownMemberMock.deviceId,
     });
-    expect(localTransport$.value).toBe(null);
+    expect(advertised$.value).toBe(null);
+    expect(active$.value).toBe(null);
     await flushPromises();
     // final
-    expect(localTransport$.value).toStrictEqual({
-      transport: {
-        livekit_alias: "!room:example.org",
-        livekit_service_url: "https://lk.example.org",
-        type: "livekit",
-      },
+    const expectedTransport = {
+      livekit_service_url: "https://lk.example.org",
+      type: "livekit",
+    };
+    expect(advertised$.value).toStrictEqual(expectedTransport);
+    expect(active$.value).toStrictEqual({
+      transport: expectedTransport,
       sfuConfig: {
         jwt: "jwt",
-        livekitAlias: "!room:example.org",
+        livekitAlias: "Akph4alDMhen",
         livekitIdentity: "@alice:example.org:DEVICE",
         url: "https://lk.example.org",
       },
     });
   });
 
-  it("updates local transport when oldest member changes", async () => {
-    // Use config so transport discovery succeeds, but delay OpenID JWT fetch
-    mockConfig({
-      livekit: { livekit_service_url: "https://lk.example.org" },
+  describe("oldest member mode", () => {
+    const aliceTransport: LivekitTransportConfig = {
+      type: "livekit",
+      livekit_service_url: "https://alice.example.org",
+    };
+    const bobTransport: LivekitTransportConfig = {
+      type: "livekit",
+      livekit_service_url: "https://bob.example.org",
+    };
+    const aliceMembership = mockRtcMembership("@alice:example.org", "AAA", {
+      fociPreferred: [aliceTransport],
     });
-    const memberships$ = new BehaviorSubject(new Epoch([]));
-    const openIdResolver = Promise.withResolvers<openIDSFU.SFUConfig>();
-
-    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockReturnValue(
-      openIdResolver.promise,
-    );
-
-    const localTransport$ = createLocalTransport$({
-      scope,
-      roomId: "!example_room_id",
-      useOldestMember$: constant(true),
-      memberships$,
-      client: {
-        getDomain: () => "",
-        // eslint-disable-next-line @typescript-eslint/naming-convention
-        _unstable_getRTCTransports: async () => Promise.resolve([]),
-        getOpenIdToken: vi.fn(),
-        getDeviceId: vi.fn(),
-        baseUrl: "https://lk.example.org",
-      },
-      ownMembershipIdentity: ownMemberMock,
-      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
-      delayId$: constant("delay_id_mock"),
+    const bobMembership = mockRtcMembership("@bob:example.org", "BBB", {
+      fociPreferred: [bobTransport],
     });
 
-    openIdResolver.resolve?.(openIdResponse);
-    expect(localTransport$.value).toBe(null);
-    await flushPromises();
-    // final
-    expect(localTransport$.value).toStrictEqual({
-      transport: {
-        livekit_alias: "!example_room_id",
-        livekit_service_url: "https://lk.example.org",
-        type: "livekit",
-      },
-      sfuConfig: {
-        jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-        livekitAlias: "!example_room_id",
-        livekitIdentity: "@lk_user:ABCDEF",
-        url: "https://lk.example.org",
-      },
+    let openIdSpy: MockInstance<(typeof openIDSFU)["getSFUConfigWithOpenID"]>;
+    beforeEach(() => {
+      openIdSpy = vi
+        .spyOn(openIDSFU, "getSFUConfigWithOpenID")
+        .mockResolvedValue(openIdResponse);
+    });
+
+    it("updates active transport when oldest member changes", async () => {
+      // Initially, Alice is the only member
+      const memberships$ = new BehaviorSubject([aliceMembership]);
+
+      const { advertised$, active$ } = createLocalTransport$({
+        scope,
+        roomId: "!example_room_id",
+        useOldestMember: true,
+        memberships$: scope.behavior(memberships$.pipe(trackEpoch())),
+        client: {
+          getDomain: () => "",
+          // eslint-disable-next-line @typescript-eslint/naming-convention
+          _unstable_getRTCTransports: async () => Promise.resolve([]),
+          getOpenIdToken: vi.fn(),
+          getDeviceId: vi.fn(),
+          baseUrl: "https://lk.example.org",
+        },
+        ownMembershipIdentity: ownMemberMock,
+        forceJwtEndpoint: JwtEndpointVersion.Legacy,
+        delayId$: constant("delay_id_mock"),
+      });
+
+      expect(active$.value).toBe(null);
+      await flushPromises();
+      // SFU config should've been fetched
+      expect(openIdSpy).toHaveBeenCalled();
+      // Alice's transport should be active and advertised
+      expect(active$.value?.transport).toStrictEqual(aliceTransport);
+      expect(advertised$.value).toStrictEqual(aliceTransport);
+
+      // Now Bob joins the call, but Alice is still the oldest member
+      openIdSpy.mockClear();
+      memberships$.next([aliceMembership, bobMembership]);
+      await flushPromises();
+      // No new SFU config should've been fetched
+      expect(openIdSpy).not.toHaveBeenCalled();
+      // Alice's transport should still be active and advertised
+      expect(active$.value?.transport).toStrictEqual(aliceTransport);
+      expect(advertised$.value).toStrictEqual(aliceTransport);
+
+      // Now Bob takes Alice's place as the oldest member
+      openIdSpy.mockClear();
+      memberships$.next([bobMembership, aliceMembership]);
+      // Active transport should reset to null until we have Bob's SFU config
+      expect(active$.value).toStrictEqual(null);
+      await flushPromises();
+      // Bob's SFU config should've been fetched
+      expect(openIdSpy).toHaveBeenCalled();
+      // Bob's transport should be active, but Alice's should remain advertised
+      // (since we don't want the change in oldest member to cause a wave of new
+      // state events)
+      expect(active$.value?.transport).toStrictEqual(bobTransport);
+      expect(advertised$.value).toStrictEqual(aliceTransport);
+    });
+
+    it("advertises preferred transport when no other member exists", async () => {
+      // Initially, there are no members
+      const memberships$ = new BehaviorSubject<CallMembership[]>([]);
+
+      const { advertised$, active$ } = createLocalTransport$({
+        scope,
+        roomId: "!example_room_id",
+        useOldestMember: true,
+        memberships$: scope.behavior(memberships$.pipe(trackEpoch())),
+        client: {
+          getDomain: () => "",
+          // eslint-disable-next-line @typescript-eslint/naming-convention
+          _unstable_getRTCTransports: async () =>
+            Promise.resolve([aliceTransport]),
+          getOpenIdToken: vi.fn(),
+          getDeviceId: vi.fn(),
+          baseUrl: "https://lk.example.org",
+        },
+        ownMembershipIdentity: ownMemberMock,
+        forceJwtEndpoint: JwtEndpointVersion.Legacy,
+        delayId$: constant("delay_id_mock"),
+      });
+
+      expect(active$.value).toBe(null);
+      await flushPromises();
+      // Our own preferred transport should be advertised
+      expect(advertised$.value).toStrictEqual(aliceTransport);
+      // No transport should be active however (there is still no oldest member)
+      expect(active$.value).toBe(null);
+
+      // Now Bob joins the call and becomes the oldest member
+      memberships$.next([bobMembership]);
+      await flushPromises();
+      // We should still advertise our own preferred transport (to avoid
+      // unnecessary state changes)
+      expect(advertised$.value).toStrictEqual(aliceTransport);
+      // Bob's transport should become active
+      expect(active$.value?.transport).toBe(bobTransport);
     });
   });
 
@@ -231,8 +314,8 @@ describe("LocalTransport", () => {
         ownMembershipIdentity: ownMemberMock,
         scope,
         roomId: "!example_room_id",
-        useOldestMember$: constant(false),
-        forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+        useOldestMember: false,
+        forceJwtEndpoint: JwtEndpointVersion.Legacy,
         delayId$: constant(null),
         memberships$: constant(new Epoch<CallMembership[]>([])),
         client: {
@@ -258,66 +341,75 @@ describe("LocalTransport", () => {
       mockConfig({
         livekit: { livekit_service_url: "https://lk.example.org" },
       });
-      const localTransport$ = createLocalTransport$(localTransportOpts);
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
       openIdResolver.resolve?.(openIdResponse);
-      expect(localTransport$.value).toBe(null);
+      expect(advertised$.value).toBe(null);
+      expect(active$.value).toBe(null);
       await flushPromises();
-      expect(localTransport$.value).toStrictEqual({
-        transport: {
-          livekit_alias: "!example_room_id",
-          livekit_service_url: "https://lk.example.org",
-          type: "livekit",
-        },
+      const expectedTransport = {
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      };
+      expect(advertised$.value).toStrictEqual(expectedTransport);
+      expect(active$.value).toStrictEqual({
+        transport: expectedTransport,
         sfuConfig: {
           jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
           livekitIdentity: "@lk_user:ABCDEF",
           url: "https://lk.example.org",
         },
       });
     });
+
     it("supports getting transport via user settings", async () => {
       customLivekitUrl.setValue("https://lk.example.org");
-      const localTransport$ = createLocalTransport$(localTransportOpts);
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
       openIdResolver.resolve?.(openIdResponse);
-      expect(localTransport$.value).toBe(null);
+      expect(advertised$.value).toBe(null);
       await flushPromises();
-      expect(localTransport$.value).toStrictEqual({
+      expect(active$.value).toStrictEqual({
         transport: {
-          livekit_alias: "!example_room_id",
           livekit_service_url: "https://lk.example.org",
           type: "livekit",
         },
         sfuConfig: {
           jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
           livekitIdentity: "@lk_user:ABCDEF",
           url: "https://lk.example.org",
         },
       });
     });
+
     it("supports getting transport via backend", async () => {
       localTransportOpts.client._unstable_getRTCTransports.mockResolvedValue([
         { type: "livekit", livekit_service_url: "https://lk.example.org" },
       ]);
-      const localTransport$ = createLocalTransport$(localTransportOpts);
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
       openIdResolver.resolve?.(openIdResponse);
-      expect(localTransport$.value).toBe(null);
+      expect(advertised$.value).toBe(null);
+      expect(active$.value).toBe(null);
       await flushPromises();
-      expect(localTransport$.value).toStrictEqual({
-        transport: {
-          livekit_alias: "!example_room_id",
-          livekit_service_url: "https://lk.example.org",
-          type: "livekit",
-        },
+      const expectedTransport = {
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      };
+      expect(advertised$.value).toStrictEqual(expectedTransport);
+      expect(active$.value).toStrictEqual({
+        transport: expectedTransport,
         sfuConfig: {
           jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
           livekitIdentity: "@lk_user:ABCDEF",
           url: "https://lk.example.org",
         },
       });
     });
+
     it("fails fast if the openID request fails for backend config", async () => {
       localTransportOpts.client._unstable_getRTCTransports.mockResolvedValue([
         { type: "livekit", livekit_service_url: "https://lk.example.org" },
@@ -325,13 +417,11 @@ describe("LocalTransport", () => {
       openIdResolver.reject(
         new FailToGetOpenIdToken(new Error("Test driven error")),
       );
-      try {
-        await lastValueFrom(createLocalTransport$(localTransportOpts));
-        throw Error("Expected test to throw");
-      } catch (ex) {
-        expect(ex).toBeInstanceOf(FailToGetOpenIdToken);
-      }
+      await expect(async () =>
+        lastValueFrom(createLocalTransport$(localTransportOpts).active$),
+      ).rejects.toThrow(expect.any(FailToGetOpenIdToken));
     });
+
     it("supports getting transport via well-known", async () => {
       localTransportOpts.client.getDomain.mockReturnValue("example.org");
       fetchMock.getOnce("https://example.org/.well-known/matrix/client", {
@@ -339,25 +429,29 @@ describe("LocalTransport", () => {
           { type: "livekit", livekit_service_url: "https://lk.example.org" },
         ],
       });
-      const localTransport$ = createLocalTransport$(localTransportOpts);
+      const { advertised$, active$ } =
+        createLocalTransport$(localTransportOpts);
       openIdResolver.resolve?.(openIdResponse);
-      expect(localTransport$.value).toBe(null);
+      expect(advertised$.value).toBe(null);
+      expect(active$.value).toBe(null);
       await flushPromises();
-      expect(localTransport$.value).toStrictEqual({
-        transport: {
-          livekit_alias: "!example_room_id",
-          livekit_service_url: "https://lk.example.org",
-          type: "livekit",
-        },
+      const expectedTransport = {
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      };
+      expect(advertised$.value).toStrictEqual(expectedTransport);
+      expect(active$.value).toStrictEqual({
+        transport: expectedTransport,
         sfuConfig: {
           jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
           livekitIdentity: "@lk_user:ABCDEF",
           url: "https://lk.example.org",
         },
       });
       expect(fetchMock.done()).toEqual(true);
     });
+
     it("fails fast if the openId request fails for the well-known config", async () => {
       localTransportOpts.client.getDomain.mockReturnValue("example.org");
       fetchMock.getOnce("https://example.org/.well-known/matrix/client", {
@@ -368,20 +462,18 @@ describe("LocalTransport", () => {
       openIdResolver.reject(
         new FailToGetOpenIdToken(new Error("Test driven error")),
       );
-      try {
-        await lastValueFrom(createLocalTransport$(localTransportOpts));
-        throw Error("Expected test to throw");
-      } catch (ex) {
-        expect(ex).toBeInstanceOf(FailToGetOpenIdToken);
-      }
+      await expect(async () =>
+        lastValueFrom(createLocalTransport$(localTransportOpts).active$),
+      ).rejects.toThrow(expect.any(FailToGetOpenIdToken));
     });
+
     it("throws if no options are available", async () => {
-      const localTransport$ = createLocalTransport$({
+      const { advertised$, active$ } = createLocalTransport$({
         scope,
         ownMembershipIdentity: ownMemberMock,
         roomId: "!example_room_id",
-        useOldestMember$: constant(false),
-        forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+        useOldestMember: false,
+        forceJwtEndpoint: JwtEndpointVersion.Legacy,
         delayId$: constant(null),
         memberships$: constant(new Epoch<CallMembership[]>([])),
         client: {
@@ -396,7 +488,10 @@ describe("LocalTransport", () => {
       });
       await flushPromises();
 
-      expect(() => localTransport$.value).toThrow(
+      expect(() => advertised$.value).toThrow(
+        new MatrixRTCTransportMissingError(""),
+      );
+      expect(() => active$.value).toThrow(
         new MatrixRTCTransportMissingError(""),
       );
     });

src/state/CallViewModel/localMember/LocalTransport.ts

@@ -7,19 +7,21 @@ Please see LICENSE in the repository root for full details.
 
 import {
   type CallMembership,
-  isLivekitTransport,
-  type LivekitTransport,
   isLivekitTransportConfig,
   type Transport,
+  type LivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { MatrixError, type MatrixClient } from "matrix-js-sdk";
 import {
-  combineLatest,
   distinctUntilChanged,
+  first,
   from,
   map,
+  merge,
   of,
+  startWith,
   switchMap,
+  tap,
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { AutoDiscovery } from "matrix-js-sdk/lib/autodiscovery";
@@ -57,9 +59,10 @@ interface Props {
     "getDomain" | "baseUrl" | "_unstable_getRTCTransports"
   > &
     OpenIDClientParts;
+  // Used by the jwt service to create the livekit room and compute the livekit alias.
   roomId: string;
-  useOldestMember$: Behavior<boolean>;
-  forceJwtEndpoint$: Behavior<JwtEndpointVersion>;
+  useOldestMember: boolean;
+  forceJwtEndpoint: JwtEndpointVersion;
   delayId$: Behavior<string | null>;
 }
 
@@ -90,26 +93,38 @@ export enum JwtEndpointVersion {
 // 2.
 // We need to make sure we do not sent livekit_alias in sticky events and that we drop all code for sending state events!
 export interface LocalTransportWithSFUConfig {
-  transport: LivekitTransport;
+  transport: LivekitTransportConfig;
   sfuConfig: SFUConfig;
 }
+
 export function isLocalTransportWithSFUConfig(
-  obj: LivekitTransport | LocalTransportWithSFUConfig,
+  obj: LivekitTransportConfig | LocalTransportWithSFUConfig,
 ): obj is LocalTransportWithSFUConfig {
   return "transport" in obj && "sfuConfig" in obj;
 }
 
+interface LocalTransport {
+  /**
+   * The transport to be advertised in our MatrixRTC membership. `null` when not
+   * yet fetched/validated.
+   */
+  advertised$: Behavior<LivekitTransportConfig | null>;
+  /**
+   * The transport to connect to and publish media on. `null` when not yet known
+   * or available.
+   */
+  active$: Behavior<LocalTransportWithSFUConfig | null>;
+}
+
 /**
- * This class is responsible for managing the local transport.
- * "Which transport is the local member going to use"
+ * Connects to the JWT service and determines the transports that the local member should use.
  *
  * @prop useOldestMember Whether to use the same transport as the oldest member.
  * This will only update once the first oldest member appears. Will not recompute if the oldest member leaves.
- *
- * @prop useOldJwtEndpoint$ Whether to set forceOldJwtEndpoint on the returned transport and to use the old JWT endpoint.
+ * @prop useOldJwtEndpoint Whether to set forceOldJwtEndpoint on the returned transport and to use the old JWT endpoint.
  * This is used when the connection manager needs to know if it has to use the legacy endpoint which implies a string concatenated rtcBackendIdentity.
  * (which is expected for non sticky event based rtc member events)
- * @returns The local transport. It will be created using the correct sfu endpoint based on the useOldJwtEndpoint$ value.
+ * @returns The transport to advertise in the local MatrixRTC membership, along with the transport to actively publish media to.
  * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
  */
 export const createLocalTransport$ = ({
@@ -118,115 +133,156 @@ export const createLocalTransport$ = ({
   ownMembershipIdentity,
   client,
   roomId,
-  useOldestMember$,
-  forceJwtEndpoint$,
+  useOldestMember,
+  forceJwtEndpoint,
   delayId$,
-}: Props): Behavior<LocalTransportWithSFUConfig | null> => {
+}: Props): LocalTransport => {
   /**
-   * The transport over which we should be actively publishing our media.
-   * undefined when not joined.
+   * The LiveKit transport in use by the oldest RTC membership. `null` when the
+   * oldest member has no such transport.
    */
-  const oldestMemberTransport$ =
-    scope.behavior<LocalTransportWithSFUConfig | null>(
-      combineLatest([memberships$, useOldestMember$]).pipe(
-        map(([memberships, useOldestMember]) => {
-          if (!useOldestMember) return null; // No need to do any prefetching if not using oldest member
-          const oldestMember = memberships.value[0];
-          const transport = oldestMember?.getTransport(oldestMember);
-          if (!transport) return null;
-          return transport;
-        }),
-        switchMap((transport) => {
-          if (transport !== null && isLivekitTransport(transport)) {
-            // Get the open jwt token to connect to the sfu
-            const computeLocalTransportWithSFUConfig =
-              async (): Promise<LocalTransportWithSFUConfig> => {
-                // await sleep(1000);
-                return {
-                  transport,
-                  sfuConfig: await getSFUConfigWithOpenID(
-                    client,
-                    ownMembershipIdentity,
-                    transport.livekit_service_url,
-                    roomId,
-                    { forceJwtEndpoint: JwtEndpointVersion.Legacy },
-                    logger,
-                  ),
-                };
-              };
-            return from(computeLocalTransportWithSFUConfig());
-          }
-          return of(null);
-        }),
-      ),
-      null,
-    );
+  const oldestMemberTransport$ = scope.behavior<LivekitTransportConfig | null>(
+    memberships$.pipe(
+      map((memberships) => {
+        const oldestMember = memberships.value[0];
+        if (oldestMember === undefined) {
+          logger.info("Oldest member: not found");
+          return null;
+        }
+        const transport = oldestMember.getTransport(oldestMember);
+        if (transport === undefined) {
+          logger.warn(
+            `Oldest member: ${oldestMember.userId}|${oldestMember.deviceId}|${oldestMember.memberId} has no transport`,
+          );
+          return null;
+        }
+        if (!isLivekitTransportConfig(transport)) {
+          logger.warn(
+            `Oldest member: ${oldestMember.userId}|${oldestMember.deviceId}|${oldestMember.memberId} has invalid transport`,
+          );
+          return null;
+        }
+        logger.info(
+          "Oldest member: ${oldestMember.userId}|${oldestMember.deviceId}|${oldestMember.memberId} has valid transport",
+        );
+        return transport;
+      }),
+      distinctUntilChanged(areLivekitTransportsEqual),
+    ),
+  );
 
   /**
    * The transport that we would personally prefer to publish on (if not for the
-   * transport preferences of others, perhaps).
+   * transport preferences of others, perhaps). `null` until fetched and
+   * validated.
    *
    * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
    */
-  const preferredTransport$ = scope.behavior(
-    // preferredTransport$ (used for multi sfu) needs to know if we are using the old or new
-    // jwt endpoint (`get_token` vs `sfu/get`) based on that the jwt endpoint will compute the rtcBackendIdentity
-    // differently. (sha(`${userId}|${deviceId}|${memberId}`) vs `${userId}|${deviceId}|${memberId}`)
-    // When using sticky events (we need to use the new endpoint).
-    combineLatest([customLivekitUrl.value$, delayId$, forceJwtEndpoint$]).pipe(
-      switchMap(([customUrl, delayId, forceEndpoint]) => {
-        logger.info(
-          "Creating preferred transport based on: ",
-          "customUrl: ",
-          customUrl,
-          "delayId: ",
-          delayId,
-          "forceEndpoint: ",
-          forceEndpoint,
-        );
-        return from(
-          makeTransport(
-            client,
-            ownMembershipIdentity,
-            roomId,
-            customUrl,
-            forceEndpoint,
-            delayId ?? undefined,
+  const preferredTransport$ =
+    scope.behavior<LocalTransportWithSFUConfig | null>(
+      // preferredTransport$ (used for multi sfu) needs to know if we are using the old or new
+      // jwt endpoint (`get_token` vs `sfu/get`) based on that the jwt endpoint will compute the rtcBackendIdentity
+      // differently. (sha(`${userId}|${deviceId}|${memberId}`) vs `${userId}|${deviceId}|${memberId}`)
+      // When using sticky events (we need to use the new endpoint).
+      customLivekitUrl.value$.pipe(
+        switchMap((customUrl) =>
+          startWith<LocalTransportWithSFUConfig | null>(null)(
+            // Fetch the SFU config, and repeat this asynchronously for every
+            // change in delay ID.
+            delayId$.pipe(
+              switchMap(async (delayId) => {
+                logger.info(
+                  "Creating preferred transport based on: ",
+                  "customUrl: ",
+                  customUrl,
+                  "delayId: ",
+                  delayId,
+                  "forceJwtEndpoint: ",
+                  forceJwtEndpoint,
+                );
+                return makeTransport(
+                  client,
+                  ownMembershipIdentity,
+                  roomId,
+                  customUrl,
+                  forceJwtEndpoint,
+                  delayId ?? undefined,
+                );
+              }),
+              // We deliberately hide any changes to the SFU config because we
+              // do not actually want the app to reconnect whenever the JWT
+              // token changes due to us delegating a new delayed event. The
+              // initial SFU config for the transport is all the app needs.
+              distinctUntilChanged((prev, next) =>
+                areLivekitTransportsEqual(prev.transport, next.transport),
+              ),
+            ),
           ),
-        );
-      }),
-    ),
-    null,
-  );
+        ),
+      ),
+    );
 
-  /**
-   * The chosen transport we should advertise in our MatrixRTC membership.
-   */
-  return scope.behavior(
-    combineLatest([
-      useOldestMember$,
-      oldestMemberTransport$,
-      preferredTransport$,
-    ]).pipe(
-      map(([useOldestMember, oldestMemberTransport, preferredTransport]) => {
-        return useOldestMember
-          ? (oldestMemberTransport ?? preferredTransport)
-          : preferredTransport;
-      }),
-      distinctUntilChanged((t1, t2) => {
-        logger.info(
-          "Local Transport Update from:",
-          t1?.transport.livekit_service_url,
-          " to ",
-          t2?.transport.livekit_service_url,
-        );
-        return areLivekitTransportsEqual(
-          t1?.transport ?? null,
-          t2?.transport ?? null,
-        );
-      }),
+  if (useOldestMember) {
+    // --- Oldest member mode ---
+    return {
+      // Never update the transport that we advertise in our membership. Just
+      // take the first valid oldest member or preferred transport that we learn
+      // about, and stick with that. This avoids unnecessary SFU hops and room
+      // state changes.
+      advertised$: scope.behavior(
+        merge(
+          oldestMemberTransport$,
+          preferredTransport$.pipe(map((t) => t?.transport ?? null)),
+        ).pipe(
+          first((t) => t !== null),
+          tap((t) =>
+            logger.info(`Advertise transport: ${t.livekit_service_url}`),
+          ),
+        ),
+        null,
+      ),
+      // Publish on the transport used by the oldest member.
+      active$: scope.behavior(
+        oldestMemberTransport$.pipe(
+          switchMap((transport) => {
+            // Oldest member not available (or invalid SFU config).
+            if (transport === null) return of(null);
+            // Oldest member available: fetch the SFU config.
+            const fetchOldestMemberTransport =
+              async (): Promise<LocalTransportWithSFUConfig> => ({
+                transport,
+                sfuConfig: await getSFUConfigWithOpenID(
+                  client,
+                  ownMembershipIdentity,
+                  transport.livekit_service_url,
+                  roomId,
+                  { forceJwtEndpoint: JwtEndpointVersion.Legacy },
+                  logger,
+                ),
+              });
+            return from(fetchOldestMemberTransport()).pipe(startWith(null));
+          }),
+          tap((t) =>
+            logger.info(
+              `Publish on transport: ${t?.transport.livekit_service_url}`,
+            ),
+          ),
+        ),
+      ),
+    };
+  }
+
+  // --- Multi-SFU mode ---
+  // Always publish on and advertise the preferred transport.
+  return {
+    advertised$: scope.behavior(
+      preferredTransport$.pipe(
+        map((t) => t?.transport ?? null),
+        distinctUntilChanged(areLivekitTransportsEqual),
+      ),
     ),
-  );
+    active$: preferredTransport$,
+  };
 };
 
 const FOCI_WK_KEY = "org.matrix.msc4143.rtc_foci";
@@ -288,18 +344,6 @@ async function makeTransport(
       transport: {
         type: "livekit",
         livekit_service_url: url,
-        // WARNING PLS READ ME!!!
-        // This looks unintuitive especially considering that `sfuConfig.livekitAlias` exists.
-        // Why do we not use: `livekit_alias: sfuConfig.livekitAlias`
-        //
-        //  - This is going to be used for sending our state event transport (focus_preferred)
-        //  - In sticky events it is expected to NOT send this field at all. The transport is only the `type`, `livekit_service_url`
-        //  - If we set it to the hased alias we get from the jwt, we will end up using the hashed alias as the body.roomId field
-        //    in v0.16.0. (It will use oldest member transport. It is using the transport.livekit_alias as the body.roomId)
-        //
-        // TLDR this is a temporal field that allow for comaptibilty but the spec expects it to not exists. (but its existance also does not break anything)
-        // It is just named poorly: It was intetended to be the actual alias. But now we do pseudonymys ids so we use a hashed alias.
-        livekit_alias: roomId,
       },
       sfuConfig,
     };

src/state/CallViewModel/remoteMembers/Connection.test.ts

@@ -26,7 +26,7 @@ import fetchMock from "fetch-mock";
 import EventEmitter from "events";
 import { type IOpenIDToken } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc/LivekitTransport";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 
 import {
   Connection,
@@ -51,8 +51,9 @@ let fakeLivekitRoom: MockedObject<LivekitRoom>;
 let localParticipantEventEmiter: EventEmitter;
 let fakeLocalParticipant: MockedObject<LocalParticipant>;
 
-const livekitFocus: LivekitTransport = {
-  livekit_alias: "!roomID:example.org",
+const ROOM_ID = "!roomID:example.org";
+
+const livekitFocus: LivekitTransportConfig = {
   livekit_service_url: "https://matrix-rtc.example.org/livekit/jwt",
   type: "livekit",
 };
@@ -112,6 +113,7 @@ function setupTest(): void {
 function setupRemoteConnection(): Connection {
   const opts: ConnectionOpts = {
     client: client,
+    roomId: ROOM_ID,
     transport: livekitFocus,
     scope: testScope,
     ownMembershipIdentity: ownMemberMock,
@@ -154,6 +156,7 @@ describe("Start connection states", () => {
 
     const opts: ConnectionOpts = {
       client: client,
+      roomId: ROOM_ID,
       transport: livekitFocus,
       scope: testScope,
       ownMembershipIdentity: ownMemberMock,
@@ -170,6 +173,7 @@ describe("Start connection states", () => {
 
     const opts: ConnectionOpts = {
       client: client,
+      roomId: ROOM_ID,
       transport: livekitFocus,
       scope: testScope,
       ownMembershipIdentity: ownMemberMock,
@@ -221,6 +225,7 @@ describe("Start connection states", () => {
 
     const opts: ConnectionOpts = {
       client: client,
+      roomId: ROOM_ID,
       transport: livekitFocus,
       scope: testScope,
       ownMembershipIdentity: ownMemberMock,
@@ -279,6 +284,7 @@ describe("Start connection states", () => {
 
     const opts: ConnectionOpts = {
       client: client,
+      roomId: ROOM_ID,
       transport: livekitFocus,
       scope: testScope,
       ownMembershipIdentity: ownMemberMock,

src/state/CallViewModel/remoteMembers/Connection.ts

@@ -15,7 +15,7 @@ import {
   type Room as LivekitRoom,
   type RemoteParticipant,
 } from "livekit-client";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject, map } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
@@ -49,9 +49,11 @@ export interface ConnectionOpts {
   /** The identity parts to use on this connection */
   ownMembershipIdentity: CallMembershipIdentityParts;
   /** The media transport to connect to. */
-  transport: LivekitTransport;
+  transport: LivekitTransportConfig;
   /** The Matrix client to use for OpenID and SFU config requests. */
   client: OpenIDClientParts;
+  /** The room ID this connection is associated with. */
+  roomId: string;
   /** The observable scope to use for this connection. */
   scope: ObservableScope;
 
@@ -102,7 +104,7 @@ export class Connection {
   /**
    * The media transport to connect to.
    */
-  public readonly transport: LivekitTransport;
+  public readonly transport: LivekitTransportConfig;
 
   public readonly livekitRoom: LivekitRoom;
 
@@ -131,6 +133,47 @@ export class Connection {
    * */
   protected stopped = false;
 
+  // TODO: can we just keep the ConnectionOpts object instead of spreading?
+  private readonly client: OpenIDClientParts;
+  private readonly roomId: string;
+  private readonly logger: Logger;
+  private readonly ownMembershipIdentity: CallMembershipIdentityParts;
+  private readonly existingSFUConfig?: SFUConfig;
+  /**
+   * Creates a new connection to a matrix RTC LiveKit backend.
+   *
+   * @param opts - Connection options {@link ConnectionOpts}.
+   *
+   * @param logger - The logger to use.
+   */
+  public constructor(opts: ConnectionOpts, logger: Logger) {
+    this.ownMembershipIdentity = opts.ownMembershipIdentity;
+    this.existingSFUConfig = opts.existingSFUConfig;
+    this.roomId = opts.roomId;
+    this.logger = logger.getChild(
+      "[Connection " + opts.transport.livekit_service_url + "]",
+    );
+    this.logger.info(
+      `constructor: ${opts.transport.livekit_service_url} roomId: ${this.roomId} withSfuConfig?: ${opts.existingSFUConfig ? JSON.stringify(opts.existingSFUConfig) : "undefined"}`,
+    );
+    const { transport, client, scope } = opts;
+
+    this.scope = scope;
+    this.livekitRoom = opts.livekitRoomFactory();
+    this.transport = transport;
+    this.client = client;
+
+    this.remoteParticipants$ = scope.behavior(
+      // Only tracks remote participants
+      connectedParticipantsObserver(this.livekitRoom),
+    );
+
+    scope.onEnd(() => {
+      this.logger.info(`Connection scope ended, stopping connection`);
+      void this.stop();
+    });
+  }
+
   /**
    * Starts the connection.
    *
@@ -231,7 +274,7 @@ export class Connection {
       this.client,
       this.ownMembershipIdentity,
       this.transport.livekit_service_url,
-      this.transport.livekit_alias,
+      this.roomId,
       // dont pass any custom opts for the subscribe only connections
       {},
       this.logger,
@@ -256,42 +299,4 @@ export class Connection {
       `stop: DONE disconnecing from lk room ${this.transport.livekit_service_url}`,
     );
   }
-
-  private readonly client: OpenIDClientParts;
-  private readonly logger: Logger;
-  private readonly ownMembershipIdentity: CallMembershipIdentityParts;
-  private readonly existingSFUConfig?: SFUConfig;
-  /**
-   * Creates a new connection to a matrix RTC LiveKit backend.
-   *
-   * @param opts - Connection options {@link ConnectionOpts}.
-   *
-   * @param logger - The logger to use.
-   */
-  public constructor(opts: ConnectionOpts, logger: Logger) {
-    this.ownMembershipIdentity = opts.ownMembershipIdentity;
-    this.existingSFUConfig = opts.existingSFUConfig;
-    this.logger = logger.getChild(
-      "[Connection " + opts.transport.livekit_service_url + "]",
-    );
-    this.logger.info(
-      `constructor: ${opts.transport.livekit_service_url} alias: ${opts.transport.livekit_alias} withSfuConfig?: ${opts.existingSFUConfig ? JSON.stringify(opts.existingSFUConfig) : "undefined"}`,
-    );
-    const { transport, client, scope } = opts;
-
-    this.scope = scope;
-    this.livekitRoom = opts.livekitRoomFactory();
-    this.transport = transport;
-    this.client = client;
-
-    this.remoteParticipants$ = scope.behavior(
-      // Only tracks remote participants
-      connectedParticipantsObserver(this.livekitRoom),
-    );
-
-    scope.onEnd(() => {
-      this.logger.info(`Connection scope ended, stopping connection`);
-      void this.stop();
-    });
-  }
 }

src/state/CallViewModel/remoteMembers/ConnectionFactory.ts

@@ -16,7 +16,7 @@ import { type Logger } from "matrix-js-sdk/lib/logger";
 // imported as inline to support worker when loaded from a cdn (cross domain)
 import E2EEWorker from "livekit-client/e2ee-worker?worker&inline";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc/LivekitTransport";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 
 import { type ObservableScope } from "../../ObservableScope.ts";
 import { Connection } from "./Connection.ts";
@@ -33,7 +33,7 @@ import { defaultLiveKitOptions } from "../../../livekit/options.ts";
 export interface ConnectionFactory {
   createConnection(
     scope: ObservableScope,
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
     ownMembershipIdentity: CallMembershipIdentityParts,
     logger: Logger,
     sfuConfig?: SFUConfig,
@@ -47,6 +47,7 @@ export class ECConnectionFactory implements ConnectionFactory {
    * Creates a ConnectionFactory for LiveKit connections.
    *
    * @param client - The OpenID client parts for authentication, needed to get openID and JWT tokens.
+   * @param roomId - The current room ID.
    * @param devices - Used for video/audio out/in capture options.
    * @param processorState$ - Effects like background blur (only for publishing connection?)
    * @param livekitKeyProvider - Optional key provider for end-to-end encryption.
@@ -57,6 +58,7 @@ export class ECConnectionFactory implements ConnectionFactory {
    */
   public constructor(
     private client: OpenIDClientParts,
+    private readonly roomId: string,
     private devices: MediaDevices,
     private processorState$: Behavior<ProcessorState>,
     livekitKeyProvider: BaseKeyProvider | undefined,
@@ -95,7 +97,7 @@ export class ECConnectionFactory implements ConnectionFactory {
    */
   public createConnection(
     scope: ObservableScope,
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
     ownMembershipIdentity: CallMembershipIdentityParts,
     logger: Logger,
     sfuConfig?: SFUConfig,
@@ -103,6 +105,7 @@ export class ECConnectionFactory implements ConnectionFactory {
     return new Connection(
       {
         existingSFUConfig: sfuConfig,
+        roomId: this.roomId,
         transport,
         client: this.client,
         scope: scope,

src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts

@@ -7,7 +7,7 @@ Please see LICENSE in the repository root for full details.
 
 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
 import { BehaviorSubject } from "rxjs";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { type RemoteParticipant } from "livekit-client";
 import { logger } from "matrix-js-sdk/lib/logger";
 
@@ -24,16 +24,14 @@ import { constant, type Behavior } from "../../Behavior.ts";
 
 // Some test constants
 
-const TRANSPORT_1: LivekitTransport = {
+const TRANSPORT_1: LivekitTransportConfig = {
   type: "livekit",
   livekit_service_url: "https://lk.example.org",
-  livekit_alias: "!alias:example.org",
 };
 
-const TRANSPORT_2: LivekitTransport = {
+const TRANSPORT_2: LivekitTransportConfig = {
   type: "livekit",
   livekit_service_url: "https://lk.sample.com",
-  livekit_alias: "!alias:sample.com",
 };
 
 let fakeConnectionFactory: ConnectionFactory;
@@ -49,7 +47,7 @@ beforeEach(() => {
   vi.mocked(fakeConnectionFactory).createConnection = vi
     .fn()
     .mockImplementation(
-      (scope: ObservableScope, transport: LivekitTransport) => {
+      (scope: ObservableScope, transport: LivekitTransportConfig) => {
         const mockConnection = {
           transport,
           remoteParticipants$: new BehaviorSubject([]),
@@ -209,15 +207,15 @@ describe("connectionManagerData$ stream", () => {
   // Used in test to control fake connections' remoteParticipants$ streams
   let fakeRemoteParticipantsStreams: Map<string, Behavior<RemoteParticipant[]>>;
 
-  function keyForTransport(transport: LivekitTransport): string {
-    return `${transport.livekit_service_url}|${transport.livekit_alias}`;
+  function keyForTransport(transport: LivekitTransportConfig): string {
+    return `${transport.livekit_service_url}`;
   }
 
   beforeEach(() => {
     fakeRemoteParticipantsStreams = new Map();
 
     function getRemoteParticipantsFor(
-      transport: LivekitTransport,
+      transport: LivekitTransportConfig,
     ): Behavior<RemoteParticipant[]> {
       return (
         fakeRemoteParticipantsStreams.get(keyForTransport(transport)) ??
@@ -229,7 +227,7 @@ describe("connectionManagerData$ stream", () => {
     vi.mocked(fakeConnectionFactory).createConnection = vi
       .fn()
       .mockImplementation(
-        (scope: ObservableScope, transport: LivekitTransport) => {
+        (scope: ObservableScope, transport: LivekitTransportConfig) => {
           const fakeRemoteParticipants$ = new BehaviorSubject<
             RemoteParticipant[]
           >([]);

src/state/CallViewModel/remoteMembers/ConnectionManager.ts

@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, map, of, switchMap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type RemoteParticipant } from "livekit-client";
@@ -42,8 +42,10 @@ export class ConnectionManagerData {
     }
   }
 
-  private getKey(transport: LivekitTransport): string {
-    return transport.livekit_service_url + "|" + transport.livekit_alias;
+  private getKey(transport: LivekitTransportConfig): string {
+    // This is enough as a key because the ConnectionManager is already scoped by room.
+    // We also do not need to consider the slotId at this point since each `MatrixRTCSession` is already scoped by `slotDescription: {id, application}`.
+    return transport.livekit_service_url;
   }
 
   public getConnections(): Connection[] {
@@ -51,15 +53,15 @@ export class ConnectionManagerData {
   }
 
   public getConnectionForTransport(
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
   ): Connection | null {
     return this.store.get(this.getKey(transport))?.connection ?? null;
   }
 
   public getParticipantsForTransport(
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
   ): RemoteParticipant[] {
-    const key = transport.livekit_service_url + "|" + transport.livekit_alias;
+    const key = this.getKey(transport);
     const existing = this.store.get(key);
     if (existing) {
       return existing.participants;
@@ -72,7 +74,7 @@ interface Props {
   scope: ObservableScope;
   connectionFactory: ConnectionFactory;
   localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
-  remoteTransports$: Behavior<Epoch<LivekitTransport[]>>;
+  remoteTransports$: Behavior<Epoch<LivekitTransportConfig[]>>;
 
   logger: Logger;
   ownMembershipIdentity: CallMembershipIdentityParts;
@@ -88,7 +90,7 @@ export interface IConnectionManager {
  * @param props - Configuration object
  * @param props.scope - The observable scope used by this object
  * @param props.connectionFactory - Used to create new connections
- * @param props.localTransport$ - The local transport to use. (deduplicated with remoteTransports$)
+ * @param props.localTransport$ - The transport to publish local media on. (deduplicated with remoteTransports$)
  * @param props.remoteTransports$ - All other transports. The connection manager will create connections for each transport. (deduplicated with localTransport$)
  * @param props.ownMembershipIdentity - The own membership identity to use.
  * @param props.logger - The logger to use.
@@ -123,7 +125,7 @@ export function createConnectionManager$({
    * externally this is modified via `registerTransports()`.
    */
   const localAndRemoteTransports$: Behavior<
-    Epoch<(LivekitTransport | LocalTransportWithSFUConfig)[]>
+    Epoch<(LivekitTransportConfig | LocalTransportWithSFUConfig)[]>
   > = scope.behavior(
     combineLatest([remoteTransports$, localTransport$]).pipe(
       // Combine local and remote transports into one transport array
@@ -161,43 +163,38 @@ export function createConnectionManager$({
     localAndRemoteTransports$.pipe(
       generateItemsWithEpoch(
         function* (transports) {
-          for (const transportWithOrWithoutSfuConfig of transports) {
-            if (
-              isLocalTransportWithSFUConfig(transportWithOrWithoutSfuConfig)
-            ) {
-              // This is the local transport only the `LocalTransportWithSFUConfig` has a `sfuConfig` field
-              const { transport, sfuConfig } = transportWithOrWithoutSfuConfig;
+          for (const transport of transports) {
+            if (isLocalTransportWithSFUConfig(transport)) {
+              // This is the local transport; only the `LocalTransportWithSFUConfig` has a `sfuConfig` field.
               yield {
                 keys: [
-                  transport.livekit_service_url,
-                  transport.livekit_alias,
-                  sfuConfig,
+                  transport.transport.livekit_service_url,
+                  transport.sfuConfig,
                 ],
                 data: undefined,
               };
             } else {
-              const transport = transportWithOrWithoutSfuConfig;
               yield {
                 keys: [
                   transport.livekit_service_url,
-                  transport.livekit_alias,
-                  undefined as undefined | SFUConfig,
+                  undefined as SFUConfig | undefined,
                 ],
                 data: undefined,
               };
             }
           }
         },
-        (scope, _data$, serviceUrl, alias, sfuConfig) => {
+        (scope, _data$, serviceUrl, sfuConfig) => {
           const connection = connectionFactory.createConnection(
             scope,
             {
               type: "livekit",
               livekit_service_url: serviceUrl,
-              livekit_alias: alias,
             },
             ownMembershipIdentity,
             logger,
+            // TODO: This whole optional SFUConfig parameter is not particularly elegant.
+            // I would like it if connections always fetched the SFUConfig by themselves.
             sfuConfig,
           );
           // Start the connection immediately
@@ -254,7 +251,7 @@ export function createConnectionManager$({
   return { connectionManagerData$ };
 }
 
-function removeDuplicateTransports<T extends LivekitTransport>(
+function removeDuplicateTransports<T extends LivekitTransportConfig>(
   transports: T[],
 ): T[] {
   return transports.reduce((acc, transport) => {

src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts

@@ -65,6 +65,7 @@ describe("ECConnectionFactory - Audio inputs options", () => {
 
       const ecConnectionFactory = new ECConnectionFactory(
         mockClient,
+        "!roomid:example.org",
         mockMediaDevices({}),
         new BehaviorSubject<ProcessorState>({
           supported: true,
@@ -105,6 +106,7 @@ describe("ECConnectionFactory - ControlledAudioDevice", () => {
 
       const ecConnectionFactory = new ECConnectionFactory(
         mockClient,
+        "!roomid:example.org",
         mockMediaDevices({
           audioOutput: {
             available$: constant(new Map<never, never>()),

src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts

@@ -7,8 +7,8 @@ Please see LICENSE in the repository root for full details.
 
 import { type LocalParticipant, type RemoteParticipant } from "livekit-client";
 import {
-  type LivekitTransport,
   type CallMembership,
+  type LivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, filter, map } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
@@ -62,7 +62,7 @@ export interface RemoteMatrixLivekitMember extends MatrixLivekitMember {
 interface Props {
   scope: ObservableScope;
   membershipsWithTransport$: Behavior<
-    Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
+    Epoch<{ membership: CallMembership; transport?: LivekitTransportConfig }[]>
   >;
   connectionManager: IConnectionManager;
 }
@@ -147,18 +147,12 @@ export function createMatrixLivekitMembers$({
 // TODO add back in the callviewmodel pauseWhen(this.pretendToBeDisconnected$)
 
 // TODO add this to the JS-SDK
-export function areLivekitTransportsEqual<T extends LivekitTransport>(
+export function areLivekitTransportsEqual<T extends LivekitTransportConfig>(
   t1: T | null,
   t2: T | null,
 ): boolean {
-  if (t1 && t2)
-    return (
-      t1.livekit_service_url === t2.livekit_service_url &&
-      // In case we have different lk rooms in the same SFU (depends on the livekit authorization service)
-      // It is only needed in case the livekit authorization service is not behaving as expected (or custom implementation)
-      // Also LivekitTransport is planned to become a `ConnectionIdentifier` which moves this equal somewhere else.
-      t1.livekit_alias === t2.livekit_alias
-    );
-  if (!t1 && !t2) return true;
-  return false;
+  if (t1 && t2) {
+    return t1.livekit_service_url === t2.livekit_service_url;
+  }
+  return !t1 && !t2;
 }

src/state/CallViewModel/remoteMembers/integration.test.ts

@@ -10,7 +10,7 @@ import { BehaviorSubject } from "rxjs";
 import { type Room as LivekitRoom } from "livekit-client";
 import EventEmitter from "events";
 import fetchMock from "fetch-mock";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { logger } from "matrix-js-sdk/lib/logger";
 
 import {
@@ -71,6 +71,7 @@ beforeEach(() => {
 
   ecConnectionFactory = new ECConnectionFactory(
     mockClient,
+    "!roomid:example.org",
     mockMediaDevices({}),
     new BehaviorSubject<ProcessorState>({
       supported: true,
@@ -148,7 +149,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
           a: expect.toSatisfy((co) =>
             areLivekitTransportsEqual(
               co.transport,
-              bobMembership.transports[0]! as LivekitTransport,
+              bobMembership.transports[0]! as LivekitTransportConfig,
             ),
           ),
         });
@@ -185,7 +186,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
               expect(
                 areLivekitTransportsEqual(
                   connection.transport,
-                  carlMembership.transports[0]! as LivekitTransport,
+                  carlMembership.transports[0]! as LivekitTransportConfig,
                 ),
               ).toBe(true);
               return true;
@@ -215,7 +216,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
               expect(
                 areLivekitTransportsEqual(
                   connection.transport,
-                  daveMembership.transports[0]! as LivekitTransport,
+                  daveMembership.transports[0]! as LivekitTransportConfig,
                 ),
               ).toBe(true);
               return true;

src/state/SessionBehaviors.ts

@@ -7,10 +7,10 @@ Please see LICENSE in the repository root for full details.
 
 import {
   type CallMembership,
-  isLivekitTransport,
-  type LivekitTransport,
+  type LivekitTransportConfig,
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
+  isLivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { fromEvent } from "rxjs";
 
@@ -27,19 +27,26 @@ export const membershipsAndTransports$ = (
   memberships$: Behavior<Epoch<CallMembership[]>>,
 ): {
   membershipsWithTransport$: Behavior<
-    Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
+    Epoch<{ membership: CallMembership; transport?: LivekitTransportConfig }[]>
   >;
-  transports$: Behavior<Epoch<LivekitTransport[]>>;
+  transports$: Behavior<Epoch<LivekitTransportConfig[]>>;
 } => {
   /**
    * Lists the transports used by ourselves, plus all other MatrixRTC session
-   * members. For completeness this also lists the preferred transport and
-   * whether we are in multi-SFU mode or sticky events mode (because
-   * advertisedTransport$ wants to read them at the same time, and bundling data
-   * together when it might change together is what you have to do in RxJS to
-   * avoid reading inconsistent state or observing too many changes.)
+   * members.
+   * For completeness this also lists the preferred transport and
+   * whether we are in multi-SFU mode or sticky events mode.
+   * `advertisedTransport$` reads these values together, so bundling them avoids inconsistent state or
+   * excessive updates when using RxJS.
    */
-  const membershipsWithTransport$ = scope.behavior(
+  const membershipsWithTransport$: Behavior<
+    Epoch<
+      {
+        membership: CallMembership;
+        transport: LivekitTransportConfig | undefined;
+      }[]
+    >
+  > = scope.behavior(
     memberships$.pipe(
       mapEpoch((memberships) => {
         return memberships.map((membership) => {
@@ -47,14 +54,16 @@ export const membershipsAndTransports$ = (
           const transport = membership.getTransport(oldestMembership);
           return {
             membership,
-            transport: isLivekitTransport(transport) ? transport : undefined,
+            transport: isLivekitTransportConfig(transport)
+              ? transport
+              : undefined,
           };
         });
       }),
     ),
   );
 
-  const transports$ = scope.behavior(
+  const transports$: Behavior<Epoch<LivekitTransportConfig[]>> = scope.behavior(
     membershipsWithTransport$.pipe(
       mapEpoch((mts) => mts.flatMap(({ transport: t }) => (t ? [t] : []))),
     ),

src/utils/observable.ts

@@ -207,6 +207,37 @@ export function filterBehavior<T, S extends T>(
     );
 }
 
+/**
+ * Maps a changing input value to an item whose lifetime is tied to a certain
+ * computed key. The item may capture some dynamic data from the input.
+ */
+export function generateItem<
+  Input,
+  Keys extends [unknown, ...unknown[]],
+  Data,
+  Item,
+>(
+  name: string,
+  generator: (input: Input) => { keys: readonly [...Keys]; data: Data },
+  factory: (
+    scope: ObservableScope,
+    data$: Behavior<Data>,
+    ...keys: Keys
+  ) => Item,
+): OperatorFunction<Input, Item> {
+  return (input$) =>
+    input$.pipe(
+      generateItemsInternal(
+        function* (input) {
+          yield generator(input);
+        },
+        factory,
+        (items) => items,
+      ),
+      map(([item]) => item),
+    );
+}
+
 function generateItemsInternal<
   Input,
   Keys extends [unknown, ...unknown[]],

src/widget.test.ts

@@ -5,7 +5,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { beforeAll, describe, expect, vi, it } from "vitest";
+import { describe, expect, vi, it, beforeEach } from "vitest";
 import { createRoomWidgetClient, EventType } from "matrix-js-sdk";
 
 import { getUrlParams } from "./UrlParams";
@@ -35,11 +35,14 @@ vi.mock("./UrlParams", () => ({
   })),
 }));
 
-initializeWidget();
-describe("widget", () => {
-  beforeAll(() => {});
+beforeEach(() => {
+  createRoomWidgetClientSpy.mockClear();
+});
 
+describe("widget", () => {
   it("should create an embedded client with the correct params", () => {
+    initializeWidget("ANYRTCAPP");
+
     expect(getUrlParams()).toStrictEqual({
       widgetId: "id",
       parentUrl: "http://parentUrl",
@@ -66,13 +69,16 @@ describe("widget", () => {
     ];
 
     const sendState = [
-      "myYser", // Legacy call membership events
-      `_myYser_AAAAA_m.call`, // Session membership events
-      `myYser_AAAAA_m.call`, // The above with no leading underscore, for room versions whose auth rules allow it
-    ].map((stateKey) => ({
-      eventType: EventType.GroupCallMemberPrefix,
-      stateKey,
-    }));
+      { eventType: "org.matrix.msc3401.call.member", stateKey: "myYser" }, // Legacy call membership events
+      {
+        eventType: "org.matrix.msc3401.call.member",
+        stateKey: `_myYser_AAAAA_ANYRTCAPP`,
+      }, // Session membership events
+      {
+        eventType: "org.matrix.msc3401.call.member",
+        stateKey: `myYser_AAAAA_ANYRTCAPP`,
+      }, // The above with no leading underscore, for room versions whose auth rules allow it
+    ];
     const receiveState = [
       { eventType: EventType.RoomCreate },
       { eventType: EventType.RoomName },
@@ -124,4 +130,32 @@ describe("widget", () => {
     });
     expect(createRoomWidgetClientSpy.mock.calls[0][4]).toStrictEqual(false);
   });
+
+  it("should request send message permission if requested", () => {
+    initializeWidget("ANYRTCAPP", true);
+    expect(createRoomWidgetClientSpy).toHaveBeenLastCalledWith(
+      expect.anything(),
+      // capabilities
+      expect.objectContaining({
+        sendEvent: expect.arrayContaining(["m.room.message"]),
+      }),
+      expect.anything(),
+      expect.anything(),
+      expect.anything(),
+    );
+  });
+
+  it("should not request send message permission when not requested", () => {
+    initializeWidget("", false);
+    expect(createRoomWidgetClientSpy).toHaveBeenLastCalledWith(
+      expect.anything(),
+      // capabilities
+      expect.objectContaining({
+        sendEvent: expect.not.arrayContaining(["m.room.message"]),
+      }),
+      expect.anything(),
+      expect.anything(),
+      expect.anything(),
+    );
+  });
 });

src/widget.ts

@@ -68,7 +68,10 @@ export let widget: WidgetHelpers | null;
  */
 // this needs to be a seperate call and cannot be done on import to allow us to spy on methods in here before
 // execution.
-export const initializeWidget = (): void => {
+export const initializeWidget = (
+  rtcApplication: string = "m.call",
+  sendRoomEvents = false,
+): void => {
   try {
     const {
       widgetId,
@@ -116,6 +119,9 @@ export const initializeWidget = (): void => {
         EventType.CallNotify, // Sent as a deprecated fallback
         EventType.RTCNotification,
       ];
+      if (sendRoomEvents) {
+        sendEvent.push(EventType.RoomMessage);
+      }
       const sendRecvEvent = [
         "org.matrix.rageshake_request",
         EventType.CallEncryptionKeysPrefix,
@@ -128,8 +134,8 @@ export const initializeWidget = (): void => {
 
       const sendState = [
         userId, // Legacy call membership events
-        `_${userId}_${deviceId}_m.call`, // Session membership events
-        `${userId}_${deviceId}_m.call`, // The above with no leading underscore, for room versions whose auth rules allow it
+        `_${userId}_${deviceId}_${rtcApplication}`, // Session membership events
+        `${userId}_${deviceId}_${rtcApplication}`, // The above with no leading underscore, for room versions whose auth rules allow it
       ].map((stateKey) => ({
         eventType: EventType.GroupCallMemberPrefix,
         stateKey,

yarn.lock

@@ -8364,7 +8364,7 @@ __metadata:
     livekit-client: "npm:^2.13.0"
     lodash-es: "npm:^4.17.21"
     loglevel: "npm:^1.9.1"
-    matrix-js-sdk: "matrix-org/matrix-js-sdk#develop"
+    matrix-js-sdk: "matrix-org/matrix-js-sdk#6e3efef0c5f660df47cf00874927dec1c75cc3cf"
     matrix-widget-api: "npm:^1.16.1"
     node-stdlib-browser: "npm:^1.3.1"
     normalize.css: "npm:^8.0.1"
@@ -11452,9 +11452,9 @@ __metadata:
   languageName: node
   linkType: hard
 
-"matrix-js-sdk@matrix-org/matrix-js-sdk#develop":
-  version: 40.0.0
-  resolution: "matrix-js-sdk@https://github.com/matrix-org/matrix-js-sdk.git#commit=dbb2ae5c0752c28639502e93f26cb3003d0d0595"
+"matrix-js-sdk@matrix-org/matrix-js-sdk#6e3efef0c5f660df47cf00874927dec1c75cc3cf":
+  version: 40.1.0
+  resolution: "matrix-js-sdk@https://github.com/matrix-org/matrix-js-sdk.git#commit=6e3efef0c5f660df47cf00874927dec1c75cc3cf"
   dependencies:
     "@babel/runtime": "npm:^7.12.5"
     "@matrix-org/matrix-sdk-crypto-wasm": "npm:^17.0.0"
@@ -11470,7 +11470,7 @@ __metadata:
     sdp-transform: "npm:^3.0.0"
     unhomoglyph: "npm:^1.0.6"
     uuid: "npm:13"
-  checksum: 10c0/9f97cec346e0dcce8599bc3afa1608f5166408260937f8311fa9af95b8fd2ff6d86422124fcb721fc830a3ec269389067334c344b4f512b64299561484135326
+  checksum: 10c0/2c4db56fd0164d801c2f125ab2a442e3659314d4cc2fd640ea152b829d0db8b05ff808020e387a761afde4ff7a07b271c25431337de9f7c765c523c8cd837e36
   languageName: node
   linkType: hard