Merge pull request #3638 from element-hq/toger5/delayed-event-delegation

Pseudonomous identity and use the new jwt service endpoint (with delayed event delegation)

backend/dev_homeserver-othersite.yaml

@@ -38,6 +38,8 @@ experimental_features:
   # MSC4222 needed for syncv2 state_after. This allow clients to
   # correctly track the state of the room.
   msc4222_enabled: true
+  # sticky events for MatrixRTC user state
+  msc4354_enabled: true
 
 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no

backend/dev_homeserver.yaml

@@ -38,7 +38,7 @@ experimental_features:
   # MSC4222 needed for syncv2 state_after. This allow clients to
   # correctly track the state of the room.
   msc4222_enabled: true
-  # sticky events for matrixRTC user state
+  # sticky events for MatrixRTC user state
   msc4354_enabled: true
 
 # The maximum allowed duration by which sent events can be delayed, as

backend/playwright_homeserver-othersite.yaml

@@ -38,6 +38,8 @@ experimental_features:
   # MSC4222 needed for syncv2 state_after. This allow clients to
   # correctly track the state of the room.
   msc4222_enabled: true
+  # sticky events for MatrixRTC user state
+  msc4354_enabled: true
 
 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no

backend/playwright_homeserver.yaml

@@ -38,6 +38,8 @@ experimental_features:
   # MSC4222 needed for syncv2 state_after. This allow clients to
   # correctly track the state of the room.
   msc4222_enabled: true
+  # sticky events for MatrixRTC user state
+  msc4354_enabled: true
 
 # The maximum allowed duration by which sent events can be delayed, as
 # per MSC4140. Must be a positive value if set.  Defaults to no

dev-backend-docker-compose.yml

@@ -3,7 +3,7 @@ networks:
 
 services:
   auth-service:
-    image: ghcr.io/element-hq/lk-jwt-service:latest-ci
+    image: ghcr.io/element-hq/lk-jwt-service:pr_139
     pull_policy: always
     hostname: auth-server
     environment:
@@ -25,7 +25,7 @@ services:
       - ecbackend
 
   auth-service-1:
-    image: ghcr.io/element-hq/lk-jwt-service:latest-ci
+    image: ghcr.io/element-hq/lk-jwt-service:pr_139
     pull_policy: always
     hostname: auth-server-1
     environment:
@@ -88,7 +88,7 @@ services:
 
   synapse:
     hostname: homeserver
-    image: docker.io/matrixdotorg/synapse:latest
+    image: ghcr.io/element-hq/synapse:pr-18968-dcb7678281bc02d4551043a6338fe5b7e6aa47ce
     pull_policy: always
     environment:
       - SYNAPSE_CONFIG_PATH=/data/cfg/homeserver.yaml
@@ -106,7 +106,7 @@ services:
 
   synapse-1:
     hostname: homeserver-1
-    image: docker.io/matrixdotorg/synapse:latest
+    image: ghcr.io/element-hq/synapse:pr-18968-dcb7678281bc02d4551043a6338fe5b7e6aa47ce
     pull_policy: always
     environment:
       - SYNAPSE_CONFIG_PATH=/data/cfg/homeserver.yaml

locales/en/app.json

@@ -116,6 +116,7 @@
     "matrix_rtc_transport_missing": "The server is not configured to work with {{brand}}. Please contact your server admin (Domain: {{domain}}, Error Code: {{ errorCode }}).",
     "membership_manager": "Membership Manager Error",
     "membership_manager_description": "The Membership Manager had to shut down. This is caused by many consequtive failed network requests.",
+    "no_matrix_2_authorization_service": "Your authorization service for you media server (SFU) is not on the newest version",
     "open_elsewhere": "Opened in another tab",
     "open_elsewhere_description": "{{brand}} has been opened in another tab. If that doesn't sound right, try reloading the page.",
     "room_creation_restricted": "Failed to create call",

package.json

@@ -125,6 +125,7 @@
     "typescript": "^5.8.3",
     "typescript-eslint-language-service": "^5.0.5",
     "unique-names-generator": "^4.6.0",
+    "uuid": "^13.0.0",
     "vaul": "^1.0.0",
     "vite": "^7.0.0",
     "vite-plugin-generate-file": "^0.3.0",

sdk/main.ts

@@ -101,12 +101,7 @@ export async function createMatrixRTCSdk(
   const mediaDevices = new MediaDevices(scope);
   const muteStates = new MuteStates(scope, mediaDevices, constant(true));
   const slot = { application, id };
-  const rtcSession = new MatrixRTCSession(
+  const rtcSession = new MatrixRTCSession(client, room, slot);
-    client,
-    room,
-    MatrixRTCSession.sessionMembershipsForSlot(room, slot),
-    slot,
-  );
   const callViewModel = createCallViewModel$(
     scope,
     rtcSession,

src/RTCConnectionStats.tsx

@@ -20,6 +20,7 @@ interface Props {
   audio?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
   video?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
   focusUrl?: string;
+  rtcBackendIdentity?: string;
 }
 
 const extractDomain = (url: string): string => {
@@ -37,6 +38,7 @@ export const RTCConnectionStats: FC<Props> = ({
   audio,
   video,
   focusUrl,
+  rtcBackendIdentity,
   ...rest
 }) => {
   const [showModal, setShowModal] = useState(false);
@@ -71,6 +73,9 @@ export const RTCConnectionStats: FC<Props> = ({
           </pre>
         </div>
       </Modal>
+      <Text as="span" size="xs" title="rtcBackendIdentity">
+        rtcBackendIdentity:{rtcBackendIdentity}
+      </Text>
       {focusUrl && (
         <div>
           <Text as="span" size="xs" title="focusURL">

src/e2ee/matrixKeyProvider.ts

@@ -6,11 +6,13 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { BaseKeyProvider } from "livekit-client";
-import { logger } from "matrix-js-sdk/lib/logger";
 import {
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
 } from "matrix-js-sdk/lib/matrixrtc";
+import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
+const logger = rootLogger.getChild("[MatrixKeyProvider]");
 
 export class MatrixKeyProvider extends BaseKeyProvider {
   private rtcSession?: MatrixRTCSession;
@@ -42,7 +44,8 @@ export class MatrixKeyProvider extends BaseKeyProvider {
   private onEncryptionKeyChanged = (
     encryptionKey: Uint8Array<ArrayBuffer>,
     encryptionKeyIndex: number,
-    participantId: string,
+    membershipParts: CallMembershipIdentityParts,
+    rtcBackendIdentity: string,
   ): void => {
     crypto.subtle
       .importKey("raw", encryptionKey, "HKDF", false, [
@@ -53,17 +56,17 @@ export class MatrixKeyProvider extends BaseKeyProvider {
         (keyMaterial) => {
           this.onSetEncryptionKey(
             keyMaterial,
-            participantId,
+            rtcBackendIdentity,
             encryptionKeyIndex,
           );
 
           logger.debug(
-            `Sent new key to livekit room=${this.rtcSession?.room.roomId} participantId=${participantId} encryptionKeyIndex=${encryptionKeyIndex}`,
+            `Sent new key to livekit room=${this.rtcSession?.room.roomId} participantId=${rtcBackendIdentity} (before hash: ${membershipParts.userId}:${membershipParts.deviceId}) encryptionKeyIndex=${encryptionKeyIndex}`,
           );
         },
         (e) => {
           logger.error(
-            `Failed to create key material from buffer for livekit room=${this.rtcSession?.room.roomId} participantId=${participantId} encryptionKeyIndex=${encryptionKeyIndex}`,
+            `Failed to create key material from buffer for livekit room=${this.rtcSession?.room.roomId} participantId before hash=${membershipParts.userId}:${membershipParts.deviceId} encryptionKeyIndex=${encryptionKeyIndex}`,
             e,
           );
         },

src/livekit/MatrixAudioRenderer.tsx

@@ -15,7 +15,6 @@ import {
   type AudioTrackProps,
 } from "@livekit/components-react";
 import { logger } from "matrix-js-sdk/lib/logger";
-import { type ParticipantId } from "matrix-js-sdk/lib/matrixrtc";
 
 import { useEarpieceAudioConfig } from "../MediaDevicesContext";
 import { useReactiveState } from "../useReactiveState";
@@ -32,7 +31,7 @@ export interface MatrixAudioRendererProps {
    * This list needs to be composed based on the matrixRTC members so that we do not play audio from users
    * that are not expected to be in the rtc session (local user is excluded).
    */
-  validIdentities: ParticipantId[];
+  validIdentities: string[];
   /**
    * If set to `true`, mutes all audio tracks rendered by the component.
    * @remarks

src/livekit/openIDSFU.test.ts

@@ -18,6 +18,7 @@ import fetchMock from "fetch-mock";
 
 import { getSFUConfigWithOpenID, type OpenIDClientParts } from "./openIDSFU";
 import { testJWTToken } from "../utils/test-fixtures";
+import { ownMemberMock } from "../utils/test";
 
 const sfuUrl = "https://sfu.example.org";
 
@@ -33,6 +34,7 @@ describe("getSFUConfigWithOpenID", () => {
     vitest.clearAllMocks();
     fetchMock.reset();
   });
+
   it("should handle fetching a token", async () => {
     fetchMock.post("https://sfu.example.org/sfu/get", () => {
       return {
@@ -42,6 +44,7 @@ describe("getSFUConfigWithOpenID", () => {
     });
     const config = await getSFUConfigWithOpenID(
       matrixClient,
+      ownMemberMock,
       "https://sfu.example.org",
       "!example_room_id",
     );
@@ -53,6 +56,7 @@ describe("getSFUConfigWithOpenID", () => {
     });
     void (await fetchMock.flush());
   });
+
   it("should fail if the SFU errors", async () => {
     fetchMock.post("https://sfu.example.org/sfu/get", () => {
       return {
@@ -63,11 +67,12 @@ describe("getSFUConfigWithOpenID", () => {
     try {
       await getSFUConfigWithOpenID(
         matrixClient,
+        ownMemberMock,
         "https://sfu.example.org",
         "!example_room_id",
       );
     } catch (ex) {
-      expect(((ex as Error).cause as Error).message).toEqual(
+      expect((ex as Error).message).toEqual(
         "SFU Config fetch failed with status code 500",
       );
       void (await fetchMock.flush());
@@ -76,6 +81,104 @@ describe("getSFUConfigWithOpenID", () => {
     expect.fail("Expected test to throw;");
   });
 
+  it("should try legacy and then new endpoint with delay delegation", async () => {
+    fetchMock.post("https://sfu.example.org/get_token", () => {
+      return {
+        status: 500,
+        body: { error: "Test failure" },
+      };
+    });
+    fetchMock.post("https://sfu.example.org/sfu/get", () => {
+      return {
+        status: 500,
+        body: { error: "Test failure" },
+      };
+    });
+    try {
+      await getSFUConfigWithOpenID(
+        matrixClient,
+        ownMemberMock,
+        "https://sfu.example.org",
+        "!example_room_id",
+        {
+          delayEndpointBaseUrl: "https://matrix.homeserverserver.org",
+          delayId: "mock_delay_id",
+        },
+      );
+    } catch (ex) {
+      expect((ex as Error).message).toEqual(
+        "SFU Config fetch failed with status code 500",
+      );
+      void (await fetchMock.flush());
+    }
+    const calls = fetchMock.calls();
+    expect(calls.length).toBe(2);
+
+    expect(calls[0][0]).toStrictEqual("https://sfu.example.org/get_token");
+    expect(calls[0][1]).toStrictEqual({
+      // check if it uses correct delayID!
+      body: '{"room_id":"!example_room_id","slot_id":"m.call#ROOM","member":{"id":"@alice:example.org:DEVICE","claimed_user_id":"@alice:example.org","claimed_device_id":"DEVICE"},"delay_id":"mock_delay_id","delay_timeout":1000,"delay_cs_api_url":"https://matrix.homeserverserver.org"}',
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+    });
+
+    expect(calls[1][0]).toStrictEqual("https://sfu.example.org/sfu/get");
+
+    expect(calls[1][1]).toStrictEqual({
+      body: '{"room":"!example_room_id","device_id":"DEVICE"}',
+      headers: {
+        "Content-Type": "application/json",
+      },
+      method: "POST",
+    });
+  });
+
+  it("dont try legacy if endpoint with delay delegation is sucessful", async () => {
+    fetchMock.post("https://sfu.example.org/get_token", () => {
+      return {
+        status: 200,
+        body: { url: sfuUrl, jwt: testJWTToken },
+      };
+    });
+    fetchMock.post("https://sfu.example.org/sfu/get", () => {
+      return {
+        status: 500,
+        body: { error: "Test failure" },
+      };
+    });
+    try {
+      await getSFUConfigWithOpenID(
+        matrixClient,
+        ownMemberMock,
+        "https://sfu.example.org",
+        "!example_room_id",
+        {
+          delayEndpointBaseUrl: "https://matrix.homeserverserver.org",
+          delayId: "mock_delay_id",
+        },
+      );
+    } catch (ex) {
+      expect((ex as Error).message).toEqual(
+        "SFU Config fetch failed with status code 500",
+      );
+      void (await fetchMock.flush());
+    }
+    const calls = fetchMock.calls();
+    expect(calls.length).toBe(1);
+
+    expect(calls[0][0]).toStrictEqual("https://sfu.example.org/get_token");
+    expect(calls[0][1]).toStrictEqual({
+      // check if it uses correct delayID!
+      body: '{"room_id":"!example_room_id","slot_id":"m.call#ROOM","member":{"id":"@alice:example.org:DEVICE","claimed_user_id":"@alice:example.org","claimed_device_id":"DEVICE"},"delay_id":"mock_delay_id","delay_timeout":1000,"delay_cs_api_url":"https://matrix.homeserverserver.org"}',
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+    });
+  });
+
   it("should retry fetching the openid token", async () => {
     let count = 0;
     matrixClient.getOpenIdToken.mockImplementation(async () => {
@@ -98,6 +201,7 @@ describe("getSFUConfigWithOpenID", () => {
     });
     const config = await getSFUConfigWithOpenID(
       matrixClient,
+      ownMemberMock,
       "https://sfu.example.org",
       "!example_room_id",
     );

src/livekit/openIDSFU.ts

@@ -5,11 +5,21 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { type IOpenIDToken, type MatrixClient } from "matrix-js-sdk";
+import {
-import { logger } from "matrix-js-sdk/lib/logger";
+  retryNetworkOperation,
+  type IOpenIDToken,
+  type MatrixClient,
+} from "matrix-js-sdk";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
+import { type Logger } from "matrix-js-sdk/lib/logger";
 
-import { FailToGetOpenIdToken } from "../utils/errors";
+import {
+  FailToGetOpenIdToken,
+  NoMatrix2AuthorizationService,
+} from "../utils/errors";
 import { doNetworkOperationWithRetry } from "../utils/matrix";
+import { Config } from "../config/Config";
+import { JwtEndpointVersion } from "../state/CallViewModel/localMember/LocalTransport";
 
 /**
  * Configuration and access tokens provided by the SFU on successful authentication.
@@ -18,6 +28,7 @@ export interface SFUConfig {
   url: string;
   jwt: string;
   livekitAlias: string;
+  // NOTE: Currently unused.
   livekitIdentity: string;
 }
 
@@ -64,15 +75,32 @@ export type OpenIDClientParts = Pick<
  * to the matrix RTC backend in order to get acces to the SFU.
  * It has built-in retry for calls to the homeserver with a backoff policy.
  * @param client The Matrix client
+ * @param membership Our own membership identity parts used to send to jwt service.
  * @param serviceUrl The URL of the livekit SFU service
- * @param matrixRoomId The Matrix room ID for which to get the SFU config
+ * @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
+ * 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.
+ * For our own connection we can only use the hashed version if we also send the new matrix2.0 sticky events.
+ * @param opts.delayEndpointBaseUrl The URL of the matrix homeserver.
+ * @param opts.delayId The delay id used for the jwt service to manage.
+ * @param logger optional logger.
  * @returns Object containing the token information
  * @throws FailToGetOpenIdToken
  */
 export async function getSFUConfigWithOpenID(
   client: OpenIDClientParts,
+  membership: CallMembershipIdentityParts,
   serviceUrl: string,
-  matrixRoomId: string,
+  roomId: string,
+  opts?: {
+    forceJwtEndpoint?: JwtEndpointVersion;
+    delayEndpointBaseUrl?: string;
+    delayId?: string;
+  },
+  logger?: Logger,
 ): Promise<SFUConfig> {
   let openIdToken: IOpenIDToken;
   try {
@@ -84,16 +112,67 @@ export async function getSFUConfigWithOpenID(
       error instanceof Error ? error : new Error("Unknown error"),
     );
   }
-  logger.debug("Got openID token", openIdToken);
+  logger?.debug("Got openID token", openIdToken);
 
-  logger.info(`Trying to get JWT for focus ${serviceUrl}...`);
+  logger?.info(`Trying to get JWT for focus ${serviceUrl}...`);
-  const sfuConfig = await getLiveKitJWT(
+
-    client,
+  let sfuConfig: { url: string; jwt: string } | undefined;
-    serviceUrl,
+
-    matrixRoomId,
+  const tryBothJwtEndpoints = opts?.forceJwtEndpoint === undefined; // This is for SFUs where we do not publish.
-    openIdToken,
+
-  );
+  const forceMatrix2Jwt =
-  logger.info(`Got JWT from call's active focus URL.`);
+    opts?.forceJwtEndpoint === JwtEndpointVersion.Matrix_2_0;
+
+  // We want to start using the new endpoint (with optional delay delegation)
+  // if we can use both or if we are forced to use the new one.
+  if (tryBothJwtEndpoints || forceMatrix2Jwt) {
+    try {
+      sfuConfig = await getLiveKitJWTWithDelayDelegation(
+        membership,
+        serviceUrl,
+        roomId,
+        openIdToken,
+        opts?.delayEndpointBaseUrl,
+        opts?.delayId,
+      );
+      logger?.info(`Got JWT from call's active focus URL.`);
+    } catch (e) {
+      if (e instanceof NotSupportedError) {
+        logger?.warn(
+          `Failed fetching jwt with matrix 2.0 endpoint (retry with legacy) Not supported`,
+          e,
+        );
+        sfuConfig = undefined;
+      } else {
+        logger?.warn(
+          `Failed fetching jwt with matrix 2.0 endpoint other issues ->`,
+          `(not going to try with legacy endpoint: forceOldJwtEndpoint is set to false, we did not get a not supported error from the sfu)`,
+          e,
+        );
+        // Make this throw a hard error in case we force the matrix2.0 endpoint.
+        if (forceMatrix2Jwt)
+          throw new NoMatrix2AuthorizationService(e as Error);
+        // NEVER get bejond this point if we forceMatrix2 and it failed!
+      }
+    }
+  }
+
+  // DEPRECATED
+  // here we either have a sfuConfig or we alredy exited because of `if (forceMatrix2) throw ...`
+  // The only case we can get into this condition is, if `forceMatrix2` is `false`
+  if (sfuConfig === undefined) {
+    sfuConfig = await getLiveKitJWT(
+      membership.deviceId,
+      serviceUrl,
+      roomId,
+      openIdToken,
+    );
+    logger?.info(`Got JWT from call's active focus URL.`);
+  }
+
+  if (!sfuConfig) {
+    throw new Error("No `sfuConfig` after trying with old and new endpoints");
+  }
 
   // Pull the details from the JWT
   const [, payloadStr] = sfuConfig.jwt.split(".");
@@ -104,33 +183,108 @@ export async function getSFUConfigWithOpenID(
     url: sfuConfig.url,
     livekitAlias: payload.video.room,
     // NOTE: Currently unused.
+    // Probably also not helpful since we now compute the backendIdentity on joining the call so we can use it for the encryption manager.
+    // The only reason for us to know it locally is to connect the right users with the lk world. (and to set our own keys)
     livekitIdentity: payload.sub,
   };
 }
-
+const RETRIES = 4;
 async function getLiveKitJWT(
-  client: OpenIDClientParts,
+  deviceId: string,
   livekitServiceURL: string,
-  roomName: string,
+  matrixRoomId: string,
   openIDToken: IOpenIDToken,
 ): Promise<{ url: string; jwt: string }> {
-  try {
+  let res: Response | undefined;
-    const res = await fetch(livekitServiceURL + "/sfu/get", {
+  await retryNetworkOperation(RETRIES, async () => {
+    res = await fetch(livekitServiceURL + "/sfu/get", {
       method: "POST",
       headers: {
         "Content-Type": "application/json",
       },
       body: JSON.stringify({
-        room: roomName,
+        // This is the actual livekit room alias. For the legacy jwt endpoint simply the room id was used.
+        room: matrixRoomId,
         openid_token: openIDToken,
-        device_id: client.getDeviceId(),
+        device_id: deviceId,
       }),
     });
-    if (!res.ok) {
+  });
-      throw new Error("SFU Config fetch failed with status code " + res.status);
+  if (!res) {
-    }
+    throw new Error(
-    return await res.json();
+      `Network error while connecting to jwt service after ${RETRIES} retries`,
-  } catch (e) {
+    );
-    throw new Error("SFU Config fetch failed with exception", { cause: e });
+  }
+  if (!res.ok) {
+    throw new Error("SFU Config fetch failed with status code " + res.status);
+  }
+  return await res.json();
+}
+
+class NotSupportedError extends Error {
+  public constructor(message: string) {
+    super(message);
+    this.name = "NotSupported";
   }
 }
+
+export async function getLiveKitJWTWithDelayDelegation(
+  membership: CallMembershipIdentityParts,
+  livekitServiceURL: string,
+  matrixRoomId: string,
+  openIDToken: IOpenIDToken,
+  delayEndpointBaseUrl?: string,
+  delayId?: string,
+): Promise<{ url: string; jwt: string }> {
+  const { userId, deviceId, memberId } = membership;
+
+  const body = {
+    room_id: matrixRoomId,
+    slot_id: "m.call#ROOM",
+    openid_token: openIDToken,
+    member: {
+      id: memberId,
+      claimed_user_id: userId,
+      claimed_device_id: deviceId,
+    },
+  };
+
+  let bodyDalayParts = {};
+  // Also check for empty string
+  if (delayId && delayEndpointBaseUrl) {
+    const delayTimeoutMs =
+      Config.get().matrix_rtc_session?.delayed_leave_event_delay_ms ?? 1000;
+    bodyDalayParts = {
+      delay_id: delayId,
+      delay_timeout: delayTimeoutMs,
+      delay_cs_api_url: delayEndpointBaseUrl,
+    };
+  }
+
+  let res: Response | undefined;
+
+  await retryNetworkOperation(RETRIES, async () => {
+    res = await fetch(livekitServiceURL + "/get_token", {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+      },
+      body: JSON.stringify({ ...body, ...bodyDalayParts }),
+    });
+  });
+
+  if (!res) {
+    throw new Error(
+      `Network error while connecting to jwt service after ${RETRIES} retries`,
+    );
+  }
+  if (!res.ok) {
+    const msg = "SFU Config fetch failed with status code " + res.status;
+    if (res.status === 404) {
+      throw new NotSupportedError(msg);
+    } else {
+      throw new Error(msg);
+    }
+  }
+  return await res.json();
+}

src/room/InCallView.tsx

@@ -798,6 +798,8 @@ export const InCallView: FC<InCallViewProps> = ({
     </div>
   );
 
+  const allConnections = useBehavior(vm.allConnections$);
+
   return (
     <div
       className={styles.inRoom}
@@ -836,8 +838,14 @@ export const InCallView: FC<InCallViewProps> = ({
             onDismiss={closeSettings}
             tab={settingsTab}
             onTabChange={setSettingsTab}
-            // TODO expose correct data to setttings modal
+            livekitRooms={allConnections
-            livekitRooms={[]}
+              .getConnections()
+              .map((connectionItem) => ({
+                room: connectionItem.livekitRoom,
+                // TODO compute is local or tag it in the livekit room items already
+                isLocal: undefined,
+                url: connectionItem.transport.livekit_service_url,
+              }))}
           />
         </>
       )}

src/settings/DeveloperSettingsTab.module.css

@@ -8,3 +8,14 @@ Please see LICENSE in the repository root for full details.
 pre {
   font-size: var(--font-size-micro);
 }
+
+.livekit_room_box {
+  border: 3px solid var(--cpd-color-bg-subtle-secondary);
+  border-radius: var(--cpd-space-8x);
+  padding: var(--cpd-space-4x);
+  margin-bottom: var(--cpd-space-4x);
+  margin-top: var(--cpd-space-4x);
+  li {
+    font-size: var(--font-size-micro);
+  }
+}

src/settings/DeveloperSettingsTab.test.tsx

@@ -7,9 +7,9 @@ Please see LICENSE in the repository root for full details.
 
 import { describe, expect, it, vi } from "vitest";
 import { render, waitFor } from "@testing-library/react";
+import { type Room as LivekitRoom } from "livekit-client";
 
 import type { MatrixClient } from "matrix-js-sdk";
-import type { Room as LivekitRoom } from "livekit-client";
 import { DeveloperSettingsTab } from "./DeveloperSettingsTab";
 
 // Mock url params hook to avoid environment-dependent snapshot churn.
@@ -30,6 +30,8 @@ function createMockLivekitRoom(
     serverInfo,
     metadata,
     engine: { client: { ws: { url: wsUrl } } },
+    localParticipant: { identity: "localParticipantIdentity" },
+    remoteParticipants: new Map(),
   } as unknown as LivekitRoom;
 
   return {
@@ -69,6 +71,8 @@ describe("DeveloperSettingsTab", () => {
         isLocal: false,
         url: "wss://remote-sfu.example.org",
         room: {
+          localParticipant: { identity: "localParticipantIdentity" },
+          remoteParticipants: new Map(),
           serverInfo: { region: "remote", version: "4.5.6" },
           metadata: "remote-metadata",
           engine: { client: { ws: { url: "wss://remote-sfu.example.org" } } },

src/settings/DeveloperSettingsTab.tsx

@@ -29,6 +29,7 @@ import {
   Label,
   RadioControl,
 } from "@vector-im/compound-web";
+import { type Room as LivekitRoom } from "livekit-client";
 
 import { FieldRow, InputField } from "../input/Input";
 import {
@@ -42,7 +43,6 @@ import {
   customLivekitUrl as customLivekitUrlSetting,
   MatrixRTCMode,
 } from "./settings";
-import type { Room as LivekitRoom } from "livekit-client";
 import styles from "./DeveloperSettingsTab.module.css";
 import { useUrlParams } from "../UrlParams";
 
@@ -275,8 +275,8 @@ export const DeveloperSettingsTab: FC<Props> = ({
           name={matrixRTCModeRadioGroup}
           control={
             <RadioControl
-              checked={matrixRTCMode === MatrixRTCMode.Compatibil}
+              checked={matrixRTCMode === MatrixRTCMode.Compatibility}
-              value={MatrixRTCMode.Compatibil}
+              value={MatrixRTCMode.Compatibility}
               onChange={onMatrixRTCModeChange}
             />
           }
@@ -304,12 +304,12 @@ export const DeveloperSettingsTab: FC<Props> = ({
         </InlineField>
       </Form>
       {livekitRooms?.map((livekitRoom) => (
-        <>
+        <div className={styles.livekit_room_box}>
-          <h3>
+          <h4>
             {t("developer_mode.livekit_sfu", {
               url: livekitRoom.url || "unknown",
             })}
-          </h3>
+          </h4>
           {livekitRoom.isLocal && <p>ws-url: {localSfuUrl?.href}</p>}
           <p>
             {t("developer_mode.livekit_server_info")}(
@@ -321,7 +321,19 @@ export const DeveloperSettingsTab: FC<Props> = ({
               : "undefined"}
             {livekitRoom.room.metadata}
           </pre>
-        </>
+          <p>Local Participant</p>
+          <pre className={styles.pre}>
+            {livekitRoom.room.localParticipant.identity}
+          </pre>
+          <p>Remote Participants</p>
+          <ul>
+            {Array.from(livekitRoom.room.remoteParticipants.keys()).map(
+              (id) => (
+                <li key={id}>{id}</li>
+              ),
+            )}
+          </ul>
+        </div>
       ))}
       <p>{t("developer_mode.environment_variables")}</p>
       <pre>{JSON.stringify(env, null, 2)}</pre>

src/settings/__snapshots__/DeveloperSettingsTab.test.tsx.snap

@@ -284,7 +284,7 @@ exports[`DeveloperSettingsTab > renders and matches snapshot 1`] = `
             name="_r_0_"
             title=""
             type="radio"
-            value="compatibil"
+            value="compatibility"
           />
           <div
             class="_ui_1qhtc_19"
@@ -349,46 +349,78 @@ exports[`DeveloperSettingsTab > renders and matches snapshot 1`] = `
       </div>
     </div>
   </form>
-  <h3>
+  <div
-    LiveKit SFU: wss://local-sfu.example.org
+    class="livekit_room_box"
-  </h3>
-  <p>
-    ws-url: 
-    wss://local-sfu.example.org/
-  </p>
-  <p>
-    LiveKit Server Info
-    (
-    local
-    )
-  </p>
-  <pre
-    class="pre"
   >
-    {
+    <h4>
+      LiveKit SFU: wss://local-sfu.example.org
+    </h4>
+    <p>
+      ws-url: 
+      wss://local-sfu.example.org/
+    </p>
+    <p>
+      LiveKit Server Info
+      (
+      local
+      )
+    </p>
+    <pre
+      class="pre"
+    >
+      {
   "region": "local",
   "version": "1.2.3"
 }
-    local-metadata
+      local-metadata
-  </pre>
+    </pre>
-  <h3>
+    <p>
-    LiveKit SFU: wss://remote-sfu.example.org
+      Local Participant
-  </h3>
+    </p>
-  <p>
+    <pre
-    LiveKit Server Info
+      class="pre"
-    (
+    >
-    remote
+      localParticipantIdentity
-    )
+    </pre>
-  </p>
+    <p>
-  <pre
+      Remote Participants
-    class="pre"
+    </p>
+    <ul />
+  </div>
+  <div
+    class="livekit_room_box"
   >
-    {
+    <h4>
+      LiveKit SFU: wss://remote-sfu.example.org
+    </h4>
+    <p>
+      LiveKit Server Info
+      (
+      remote
+      )
+    </p>
+    <pre
+      class="pre"
+    >
+      {
   "region": "remote",
   "version": "4.5.6"
 }
-    remote-metadata
+      remote-metadata
-  </pre>
+    </pre>
+    <p>
+      Local Participant
+    </p>
+    <pre
+      class="pre"
+    >
+      localParticipantIdentity
+    </pre>
+    <p>
+      Remote Participants
+    </p>
+    <ul />
+  </div>
   <p>
     Environment variables
   </p>

src/settings/settings.ts

@@ -126,7 +126,13 @@ export const alwaysShowIphoneEarpiece = new Setting<boolean>(
 
 export enum MatrixRTCMode {
   Legacy = "legacy",
-  Compatibil = "compatibil",
+  Compatibility = "compatibility",
+  /** This implies using
+   *  - sticky events
+   *  - hashed RTC backend identity
+   *  - the new endpoint for the jwt token on the local membership (remote memberships will always try the new jwt endpoint first -> then the legacy one)
+   *  - use the hashed identity for the local membership
+   */
   Matrix_2_0 = "matrix_2_0",
 }
 

src/state/CallViewModel/CallViewModel.test.ts

@@ -78,11 +78,14 @@ vi.mock("../e2ee/matrixKeyProvider");
 const getUrlParams = vi.hoisted(() => vi.fn(() => ({})));
 vi.mock("../UrlParams", () => ({ getUrlParams }));
 
-vi.mock("../rtcSessionHelpers", async (importOriginal) => ({
+vi.mock(
-  ...(await importOriginal()),
+  "../state/CallViewModel/localMember/localTransport",
-  makeTransport: async (): Promise<LivekitTransport> =>
+  async (importOriginal) => ({
-    Promise.resolve(exampleTransport),
+    ...(await importOriginal()),
-}));
+    makeTransport: async (): Promise<LivekitTransport> =>
+      Promise.resolve(exampleTransport),
+  }),
+);
 
 const yesNo = {
   y: true,
@@ -232,7 +235,7 @@ const mockLegacyRingEvent = {} as { event_id: string } & ICallNotifyContent;
 
 describe.each([
   [MatrixRTCMode.Legacy],
-  [MatrixRTCMode.Compatibil],
+  [MatrixRTCMode.Compatibility],
   [MatrixRTCMode.Matrix_2_0],
 ])("CallViewModel (%s mode)", (mode) => {
   const withCallViewModel = withCallViewModelInMode(mode);
@@ -1255,11 +1258,6 @@ describe.each([
             y: () => {
               rtcSession.membershipStatus = Status.Connected;
             },
-            n: () => {
-              // NOTE: This was removed in https://github.com/matrix-org/matrix-js-sdk/pull/5103 accidentally.
-              // eslint-disable-next-line @typescript-eslint/no-explicit-any
-              rtcSession.membershipStatus = "Reconnecting" as any;
-            },
           });
           schedule(probablyLeftMarbles, {
             y: () => {

src/state/CallViewModel/CallViewModel.ts

@@ -41,10 +41,13 @@ import {
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import {
+  MembershipManagerEvent,
   type LivekitTransport,
   type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { type IWidgetApiRequest } from "matrix-widget-api";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
+import { v4 as uuidv4 } from "uuid";
 
 import {
   LocalUserMediaViewModel,
@@ -98,7 +101,7 @@ import {
   type SpotlightLandscapeLayoutMedia,
   type SpotlightPortraitLayoutMedia,
 } from "../layout-types.ts";
-import { ElementCallError } from "../../utils/errors.ts";
+import { ElementCallError, UnknownCallError } from "../../utils/errors.ts";
 import { type ObservableScope } from "../ObservableScope.ts";
 import { createHomeserverConnected$ } from "./localMember/HomeserverConnected.ts";
 import {
@@ -106,13 +109,19 @@ import {
   enterRTCSession,
   TransportState,
 } from "./localMember/LocalMember.ts";
-import { createLocalTransport$ } from "./localMember/LocalTransport.ts";
+import {
+  createLocalTransport$,
+  JwtEndpointVersion,
+} from "./localMember/LocalTransport.ts";
 import {
   createMemberships$,
   membershipsAndTransports$,
 } from "../SessionBehaviors.ts";
 import { ECConnectionFactory } from "./remoteMembers/ConnectionFactory.ts";
-import { createConnectionManager$ } from "./remoteMembers/ConnectionManager.ts";
+import {
+  type ConnectionManagerData,
+  createConnectionManager$,
+} from "./remoteMembers/ConnectionManager.ts";
 import {
   createMatrixLivekitMembers$,
   type TaggedParticipant,
@@ -261,6 +270,7 @@ export interface CallViewModel {
    *    multiple devices.
    */
   participantCount$: Behavior<number>;
+  allConnections$: Behavior<ConnectionManagerData>;
   /** Participants sorted by livekit room so they can be used in the audio rendering */
   livekitRoomItems$: Behavior<LivekitRoomItem[]>;
   userMedia$: Behavior<UserMedia[]>;
@@ -381,8 +391,11 @@ export function createCallViewModel$(
   trackProcessorState$: Behavior<ProcessorState>,
 ): CallViewModel {
   const client = matrixRoom.client;
-  const userId = client.getUserId()!;
+  const userId = client.getUserId();
-  const deviceId = client.getDeviceId()!;
+  const deviceId = client.getDeviceId();
+  if (!(userId && deviceId))
+    throw new UnknownCallError(new Error("userId and deviceId are required"));
+
   const livekitKeyProvider = getE2eeKeyProvider(
     options.encryptionSystem,
     matrixRTCSession,
@@ -415,11 +428,37 @@ export function createCallViewModel$(
     memberships$,
   );
 
+  const ownMembershipIdentity: CallMembershipIdentityParts = {
+    userId,
+    deviceId,
+    // This will only be consumed by the sticky membership manager. So it has no impact on legacy calls.
+    memberId: uuidv4(),
+  };
+
   const localTransport$ = createLocalTransport$({
     scope: scope,
     memberships$: memberships$,
+    ownMembershipIdentity,
     client,
+    delayId$: scope.behavior(
+      (
+        fromEvent(
+          matrixRTCSession,
+          MembershipManagerEvent.DelayIdChanged,
+        ) as Observable<string | undefined>
+      ).pipe(map((v) => v ?? 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,
+        ),
+      ),
+    ),
     useOldestMember$: scope.behavior(
       matrixRTCMode$.pipe(map((v) => v === MatrixRTCMode.Legacy)),
     ),
@@ -439,30 +478,20 @@ export function createCallViewModel$(
   const connectionManager = createConnectionManager$({
     scope: scope,
     connectionFactory: connectionFactory,
-    inputTransports$: scope.behavior(
+    localTransport$: scope.behavior(
-      combineLatest(
+      localTransport$.pipe(
-        [
+        catchError((e: unknown) => {
-          localTransport$.pipe(
+          logger.info(
-            catchError((e: unknown) => {
+            "could not pass local transport to createConnectionManager$. localTransport$ threw an error",
-              logger.info(
+            e,
-                "dont pass local transport to createConnectionManager$. localTransport$ threw an error",
+          );
-                e,
+          return of(null);
-              );
+        }),
-              return of(null);
-            }),
-          ),
-          membershipsAndTransports.transports$,
-        ],
-        (localTransport, transports) => {
-          const localTransportAsArray = localTransport ? [localTransport] : [];
-          return transports.mapInner((transports) => [
-            ...localTransportAsArray,
-            ...transports,
-          ]);
-        },
       ),
     ),
-    logger,
+    remoteTransports$: membershipsAndTransports.transports$,
+    logger: logger,
+    ownMembershipIdentity,
   });
 
   const matrixLivekitMembers$ = createMatrixLivekitMembers$({
@@ -493,6 +522,7 @@ export function createCallViewModel$(
     joinMatrixRTC: (transport: LivekitTransport) => {
       return enterRTCSession(
         matrixRTCSession,
+        ownMembershipIdentity,
         transport,
         connectOptions$.value,
       );
@@ -604,15 +634,14 @@ export function createCallViewModel$(
     ),
   );
 
+  const allConnections$ = scope.behavior(
+    connectionManager.connectionManagerData$.pipe(map((d) => d.value)),
+  );
   const livekitRoomItems$ = scope.behavior(
     matrixLivekitMembers$.pipe(
-      tap((val) => {
+      switchMap((members) => {
-        logger.debug("matrixLivekitMembers$ updated", val.value);
-      }),
-      switchMap((membersWithEpoch) => {
-        const members = membersWithEpoch.value;
         const a$ = combineLatest(
-          members.map((member) =>
+          members.value.map((member) =>
             combineLatest([member.connection$, member.participant.value$]).pipe(
               map(([connection, participant]) => {
                 // do not render audio for local participant
@@ -685,29 +714,29 @@ export function createCallViewModel$(
       generateItems(
         function* ([
           localMatrixLivekitMember,
-          { value: matrixLivekitMembers },
+          matrixLivekitMembers,
           duplicateTiles,
         ]) {
-          let localParticipantId: string | undefined = undefined;
+          let localUserMediaId: string | undefined = undefined;
           // add local member if available
           if (localMatrixLivekitMember) {
             const { userId, participant, connection$, membership$ } =
               localMatrixLivekitMember;
-            localParticipantId = `${userId}:${membership$.value.deviceId}`; // should be membership$.value.membershipID which is not optional
+
-            // const participantId = membership$.value.membershipID;
+            localUserMediaId = `${userId}:${membership$.value.deviceId}`;
-            if (localParticipantId) {
+            const rtcBackendIdentity = membership$.value.rtcBackendIdentity;
-              for (let dup = 0; dup < 1 + duplicateTiles; dup++) {
+            for (let dup = 0; dup < 1 + duplicateTiles; dup++) {
-                yield {
+              yield {
-                  keys: [
+                keys: [
-                    dup,
+                  dup,
-                    localParticipantId,
+                  localUserMediaId,
-                    userId,
+                  userId,
-                    participant satisfies TaggedParticipant as TaggedParticipant, // Widen the type safely
+                  participant satisfies TaggedParticipant as TaggedParticipant, // Widen the type safely
-                    connection$,
+                  connection$,
-                  ],
+                  rtcBackendIdentity,
-                  data: undefined,
+                ],
-                };
+                data: undefined,
-              }
+              };
             }
           }
           // add remote members that are available
@@ -716,13 +745,22 @@ export function createCallViewModel$(
             participant,
             connection$,
             membership$,
-          } of matrixLivekitMembers) {
+          } of matrixLivekitMembers.value) {
-            const participantId = `${userId}:${membership$.value.deviceId}`;
+            const userMediaId = `${userId}:${membership$.value.deviceId}`;
-            if (participantId === localParticipantId) continue;
+            const rtcBackendIdentity = membership$.value.rtcBackendIdentity;
-            // const participantId = membership$.value?.identity;
+            // skip local user as we added them manually before
+            if (userMediaId === localUserMediaId) continue;
+
             for (let dup = 0; dup < 1 + duplicateTiles; dup++) {
               yield {
-                keys: [dup, participantId, userId, participant, connection$],
+                keys: [
+                  dup,
+                  userMediaId,
+                  userId,
+                  participant,
+                  connection$,
+                  rtcBackendIdentity,
+                ],
                 data: undefined,
               };
             }
@@ -732,10 +770,11 @@ export function createCallViewModel$(
           scope,
           _data$,
           dup,
-          participantId,
+          userMediaId,
           userId,
           participant,
           connection$,
+          rtcBackendIdentity,
         ) => {
           const livekitRoom$ = scope.behavior(
             connection$.pipe(map((c) => c?.livekitRoom)),
@@ -751,8 +790,9 @@ export function createCallViewModel$(
 
           return new UserMedia(
             scope,
-            `${participantId}:${dup}`,
+            `${userMediaId}:${dup}`,
             userId,
+            rtcBackendIdentity,
             participant,
             options.encryptionSystem,
             livekitRoom$,
@@ -761,8 +801,8 @@ export function createCallViewModel$(
             localMembership.reconnecting$,
             displayName$,
             matrixMemberMetadataStore.createAvatarUrlBehavior$(userId),
-            handsRaised$.pipe(map((v) => v[participantId]?.time ?? null)),
+            handsRaised$.pipe(map((v) => v[userMediaId]?.time ?? null)),
-            reactions$.pipe(map((v) => v[participantId] ?? undefined)),
+            reactions$.pipe(map((v) => v[userMediaId] ?? undefined)),
           );
         },
       ),
@@ -1503,6 +1543,7 @@ export function createCallViewModel$(
       ),
       null,
     ),
+    allConnections$,
     participantCount$: participantCount$,
     handsRaised$: handsRaised$,
     reactions$: reactions$,

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

@@ -24,6 +24,7 @@ import {
   mockLivekitRoom,
   mockMuteStates,
   withTestScheduler,
+  ownMemberMock,
 } from "../../../utils/test";
 import {
   TransportState,
@@ -38,6 +39,7 @@ 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";
 
 const MATRIX_RTC_MODE = MatrixRTCMode.Legacy;
 const getUrlParams = vi.hoisted(() => vi.fn(() => ({})));
@@ -103,11 +105,12 @@ describe("LocalMembership", () => {
         getOldestMembership: vi.fn().mockReturnValue({
           getPreferredFoci: vi.fn().mockReturnValue([focusFromOlderMembership]),
         }),
-        joinRoomSession: vi.fn(),
+        joinRTCSession: vi.fn(),
       }) as unknown as MatrixRTCSession;
 
       enterRTCSession(
         mockedSession,
+        ownMemberMock,
         {
           livekit_alias: "roomId",
           livekit_service_url: "http://my-well-known-service-url.com",
@@ -119,7 +122,12 @@ describe("LocalMembership", () => {
         },
       );
 
-      expect(mockedSession.joinRoomSession).toHaveBeenLastCalledWith(
+      expect(mockedSession.joinRTCSession).toHaveBeenLastCalledWith(
+        {
+          deviceId: "DEVICE",
+          memberId: "@alice:example.org:DEVICE",
+          userId: "@alice:example.org",
+        },
         [
           {
             livekit_alias: "roomId",
@@ -161,11 +169,12 @@ describe("LocalMembership", () => {
         },
         memberships: [],
         getFocusInUse: vi.fn(),
-        joinRoomSession: vi.fn(),
+        joinRTCSession: vi.fn(),
       }) as unknown as MatrixRTCSession;
 
       enterRTCSession(
         mockedSession,
+        ownMemberMock,
         {
           livekit_alias: "roomId",
           livekit_service_url: "http://my-well-known-service-url.com",
@@ -204,10 +213,11 @@ describe("LocalMembership", () => {
 
   it("throws error on missing RTC config error", () => {
     withTestScheduler(({ scope, hot, expectObservable }) => {
-      const localTransport$ = scope.behavior<null | LivekitTransport>(
+      const localTransport$ =
-        hot("1ms #", {}, new MatrixRTCTransportMissingError("domain.com")),
+        scope.behavior<null | LocalTransportWithSFUConfig>(
-        null,
+          hot("1ms #", {}, new MatrixRTCTransportMissingError("domain.com")),
-      );
+          null,
+        );
 
       // we do not need any connection data since we want to fail before reaching that.
       const mockConnectionManager = {
@@ -235,11 +245,23 @@ describe("LocalMembership", () => {
   });
 
   const aTransport = {
-    livekit_service_url: "a",
+    transport: {
-  } as LivekitTransport;
+      livekit_service_url: "a",
+    } as LivekitTransport,
+    sfuConfig: {
+      url: "sfu-url",
+      jwt: "sfu-token",
+    },
+  } as LocalTransportWithSFUConfig;
   const bTransport = {
-    livekit_service_url: "b",
+    transport: {
-  } as LivekitTransport;
+      livekit_service_url: "b",
+    } as LivekitTransport,
+    sfuConfig: {
+      url: "sfu-url",
+      jwt: "sfu-token",
+    },
+  } as LocalTransportWithSFUConfig;
 
   const connectionTransportAConnected = {
     livekitRoom: mockLivekitRoom({
@@ -249,7 +271,7 @@ describe("LocalMembership", () => {
       } as unknown as LocalParticipant,
     }),
     state$: constant(ConnectionState.LivekitConnected),
-    transport: aTransport,
+    transport: aTransport.transport,
   } as unknown as Connection;
   const connectionTransportAConnecting = {
     ...connectionTransportAConnected,
@@ -258,11 +280,11 @@ describe("LocalMembership", () => {
   } as unknown as Connection;
   const connectionTransportBConnected = {
     state$: constant(ConnectionState.LivekitConnected),
-    transport: bTransport,
+    transport: bTransport.transport,
     livekitRoom: mockLivekitRoom({}),
   } as unknown as Connection;
 
-  it("recreates publisher if new connection is used and ENDS always unpublish and end tracks", async () => {
+  it("recreates publisher if new connection is used, always unpublish and end tracks", async () => {
     const scope = new ObservableScope();
 
     const localTransport$ = new BehaviorSubject(aTransport);
@@ -310,8 +332,12 @@ describe("LocalMembership", () => {
     expect(publishers[1].stopTracks).not.toHaveBeenCalled();
     expect(publishers[0].stopPublishing).toHaveBeenCalled();
     expect(publishers[1].stopPublishing).not.toHaveBeenCalled();
-    expect(publisherFactory.mock.calls[0][0].transport).toBe(aTransport);
+    expect(publisherFactory.mock.calls[0][0].transport).toBe(
-    expect(publisherFactory.mock.calls[1][0].transport).toBe(bTransport);
+      aTransport.transport,
+    );
+    expect(publisherFactory.mock.calls[1][0].transport).toBe(
+      bTransport.transport,
+    );
     scope.end();
     await flushPromises();
     // stop all tracks after ending scopes
@@ -383,7 +409,8 @@ describe("LocalMembership", () => {
     const scope = new ObservableScope();
 
     const connectionManagerData = new ConnectionManagerData();
-    const localTransport$ = new BehaviorSubject<null | LivekitTransport>(null);
+    const localTransport$ =
+      new BehaviorSubject<null | LocalTransportWithSFUConfig>(null);
     const connectionManagerData$ = new BehaviorSubject(
       new Epoch(connectionManagerData),
     );
@@ -460,7 +487,7 @@ describe("LocalMembership", () => {
     });
 
     (
-      connectionManagerData2.getConnectionForTransport(aTransport)!
+      connectionManagerData2.getConnectionForTransport(aTransport.transport)!
         .state$ as BehaviorSubject<ConnectionState>
     ).next(ConnectionState.LivekitConnected);
     expect(localMembership.localMemberState$.value).toStrictEqual({

src/state/CallViewModel/localMember/LocalMember.ts

@@ -36,6 +36,7 @@ import {
 } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { deepCompare } from "matrix-js-sdk/lib/utils";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type IConnectionManager } from "../remoteMembers/ConnectionManager.ts";
@@ -60,6 +61,7 @@ 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 */
@@ -125,7 +127,7 @@ interface Props {
   createPublisherFactory: (connection: Connection) => Publisher;
   joinMatrixRTC: (transport: LivekitTransport) => void;
   homeserverConnected: HomeserverConnected;
-  localTransport$: Behavior<LivekitTransport | null>;
+  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
   matrixRTCSession: Pick<
     MatrixRTCSession,
     "updateCallIntent" | "leaveRoomSession"
@@ -233,7 +235,9 @@ export const createLocalMembership$ = ({
           return null;
         }
 
-        return connectionData.getConnectionForTransport(localTransport);
+        return connectionData.getConnectionForTransport(
+          localTransport.transport,
+        );
       }),
       tap((connection) => {
         logger.info(
@@ -532,7 +536,7 @@ export const createLocalMembership$ = ({
       if (!shouldConnect) return;
 
       try {
-        joinMatrixRTC(transport);
+        joinMatrixRTC(transport.transport);
       } catch (error) {
         logger.error("Error entering RTC session", error);
         if (error instanceof Error)
@@ -551,7 +555,12 @@ export const createLocalMembership$ = ({
   );
 
   const participant$ = scope.behavior(
-    localConnection$.pipe(map((c) => c?.livekitRoom?.localParticipant ?? null)),
+    localConnection$.pipe(
+      map((c) => c?.livekitRoom?.localParticipant ?? null),
+      tap((p) => {
+        logger.debug("participant$ updated:", p?.identity);
+      }),
+    ),
   );
 
   // Pause upstream of all local media tracks when we're disconnected from
@@ -686,18 +695,19 @@ interface EnterRTCSessionOptions {
  *      - Handles retries (fails only after several attempts)
  *
  * @param rtcSession - The MatrixRTCSession to join.
+ * @param ownMembershipIdentity - Options for entering the RTC session.
  * @param transport - The LivekitTransport to use for this session.
- * @param options - Options for entering the RTC session.
+ * @param options - `encryptMedia`: Whether to encrypt media `matrixRTCMode`: The Matrix RTC mode to use.
- * @param options.encryptMedia - Whether to encrypt media.
- * @param options.matrixRTCMode - The Matrix RTC mode to use.
  * @throws If the widget could not send ElementWidgetActions.JoinCall action.
  */
 // Exported for unit testing
 export function enterRTCSession(
   rtcSession: MatrixRTCSession,
+  ownMembershipIdentity: CallMembershipIdentityParts,
   transport: LivekitTransport,
-  { encryptMedia, matrixRTCMode }: EnterRTCSessionOptions,
+  options: EnterRTCSessionOptions,
 ): void {
+  const { encryptMedia, matrixRTCMode } = options;
   PosthogAnalytics.instance.eventCallEnded.cacheStartCall(new Date());
   PosthogAnalytics.instance.eventCallStarted.track(rtcSession.room.roomId);
 
@@ -709,10 +719,13 @@ export function enterRTCSession(
   const useDeviceSessionMemberEvents =
     features?.feature_use_device_session_member_events;
   const { sendNotificationType: notificationType, callIntent } = getUrlParams();
-  const multiSFU = matrixRTCMode !== MatrixRTCMode.Legacy;
+  const multiSFU =
+    matrixRTCMode === MatrixRTCMode.Compatibility ||
+    matrixRTCMode === MatrixRTCMode.Matrix_2_0;
   // 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.joinRoomSession(
+  rtcSession.joinRTCSession(
+    ownMembershipIdentity,
     multiSFU ? [] : [transport],
     multiSFU ? transport : undefined,
     {

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

@@ -18,8 +18,8 @@ import { type CallMembership } from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject, lastValueFrom } from "rxjs";
 import fetchMock from "fetch-mock";
 
-import { mockConfig, flushPromises } from "../../../utils/test";
+import { mockConfig, flushPromises, ownMemberMock } from "../../../utils/test";
-import { createLocalTransport$ } from "./LocalTransport";
+import { createLocalTransport$, JwtEndpointVersion } from "./LocalTransport";
 import { constant } from "../../Behavior";
 import { Epoch, ObservableScope } from "../../ObservableScope";
 import {
@@ -39,11 +39,35 @@ describe("LocalTransport", () => {
   };
 
   let scope: ObservableScope;
-  beforeEach(() => {
+  beforeEach(() => (scope = new ObservableScope()));
-    scope = new ObservableScope();
-  });
   afterEach(() => scope.end());
 
+  it("throws if config is missing", async () => {
+    const localTransport$ = createLocalTransport$({
+      scope,
+      roomId: "!room:example.org",
+      useOldestMember$: constant(false),
+      memberships$: constant(new Epoch<CallMembership[]>([])),
+      client: {
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        _unstable_getRTCTransports: async () => Promise.resolve([]),
+        getDomain: () => "",
+        baseUrl: "example.org",
+        // These won't be called in this error path but satisfy the type
+        getOpenIdToken: vi.fn(),
+        getDeviceId: vi.fn(),
+      },
+      ownMembershipIdentity: ownMemberMock,
+      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      delayId$: constant("delay_id_mock"),
+    });
+    await flushPromises();
+
+    expect(() => localTransport$.value).toThrow(
+      new MatrixRTCTransportMissingError(""),
+    );
+  });
+
   it("throws FailToGetOpenIdToken when OpenID fetch fails", async () => {
     // Provide a valid config so makeTransportInternal resolves a transport
     const scope = new ObservableScope();
@@ -65,6 +89,7 @@ describe("LocalTransport", () => {
       useOldestMember$: constant(false),
       memberships$: constant(new Epoch<CallMembership[]>([])),
       client: {
+        baseUrl: "https://lk.example.org",
         // Use empty domain to skip .well-known and use config directly
         getDomain: () => "",
         // eslint-disable-next-line @typescript-eslint/naming-convention
@@ -72,6 +97,9 @@ describe("LocalTransport", () => {
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
       },
+      ownMembershipIdentity: ownMemberMock,
+      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      delayId$: constant("delay_id_mock"),
     });
     localTransport$.subscribe(
       (o) => observations.push(o),
@@ -86,6 +114,60 @@ describe("LocalTransport", () => {
     expect(() => localTransport$.value).toThrow(expectedError);
   });
 
+  it("emits preferred transport after OpenID resolves", async () => {
+    // Use config so transport discovery succeeds, but delay OpenID JWT fetch
+    mockConfig({
+      livekit: { livekit_service_url: "https://lk.example.org" },
+    });
+
+    const openIdResolver = Promise.withResolvers<openIDSFU.SFUConfig>();
+
+    vi.spyOn(openIDSFU, "getSFUConfigWithOpenID").mockReturnValue(
+      openIdResolver.promise,
+    );
+
+    const localTransport$ = createLocalTransport$({
+      scope,
+      roomId: "!room:example.org",
+      useOldestMember$: constant(false),
+      memberships$: constant(new Epoch<CallMembership[]>([])),
+      client: {
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        _unstable_getRTCTransports: async () => Promise.resolve([]),
+        getDomain: () => "",
+        getOpenIdToken: vi.fn(),
+        getDeviceId: vi.fn(),
+        baseUrl: "https://lk.example.org",
+      },
+      ownMembershipIdentity: ownMemberMock,
+      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      delayId$: constant("delay_id_mock"),
+    });
+
+    openIdResolver.resolve?.({
+      url: "https://lk.example.org",
+      jwt: "jwt",
+      livekitAlias: "!room:example.org",
+      livekitIdentity: ownMemberMock.userId + ":" + ownMemberMock.deviceId,
+    });
+    expect(localTransport$.value).toBe(null);
+    await flushPromises();
+    // final
+    expect(localTransport$.value).toStrictEqual({
+      transport: {
+        livekit_alias: "!room:example.org",
+        livekit_service_url: "https://lk.example.org",
+        type: "livekit",
+      },
+      sfuConfig: {
+        jwt: "jwt",
+        livekitAlias: "!room:example.org",
+        livekitIdentity: "@alice:example.org:DEVICE",
+        url: "https://lk.example.org",
+      },
+    });
+  });
+
   it("updates local transport when oldest member changes", async () => {
     // Use config so transport discovery succeeds, but delay OpenID JWT fetch
     mockConfig({
@@ -109,7 +191,11 @@ describe("LocalTransport", () => {
         _unstable_getRTCTransports: async () => Promise.resolve([]),
         getOpenIdToken: vi.fn(),
         getDeviceId: vi.fn(),
+        baseUrl: "https://lk.example.org",
       },
+      ownMembershipIdentity: ownMemberMock,
+      forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+      delayId$: constant("delay_id_mock"),
     });
 
     openIdResolver.resolve?.(openIdResponse);
@@ -117,9 +203,17 @@ describe("LocalTransport", () => {
     await flushPromises();
     // final
     expect(localTransport$.value).toStrictEqual({
-      livekit_alias: "!example_room_id",
+      transport: {
-      livekit_service_url: "https://lk.example.org",
+        livekit_alias: "!example_room_id",
-      type: "livekit",
+        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",
+      },
     });
   });
 
@@ -134,11 +228,15 @@ describe("LocalTransport", () => {
       mockConfig({});
       customLivekitUrl.setValue(customLivekitUrl.defaultValue);
       localTransportOpts = {
+        ownMembershipIdentity: ownMemberMock,
         scope,
         roomId: "!example_room_id",
         useOldestMember$: constant(false),
+        forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+        delayId$: constant(null),
         memberships$: constant(new Epoch<CallMembership[]>([])),
         client: {
+          baseUrl: "https://example.org",
           getDomain: vi.fn().mockReturnValue(""),
           // eslint-disable-next-line @typescript-eslint/naming-convention
           _unstable_getRTCTransports: vi.fn().mockResolvedValue([]),
@@ -165,9 +263,17 @@ describe("LocalTransport", () => {
       expect(localTransport$.value).toBe(null);
       await flushPromises();
       expect(localTransport$.value).toStrictEqual({
-        livekit_alias: "!example_room_id",
+        transport: {
-        livekit_service_url: "https://lk.example.org",
+          livekit_alias: "!example_room_id",
-        type: "livekit",
+          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",
+        },
       });
     });
     it("supports getting transport via user settings", async () => {
@@ -177,9 +283,17 @@ describe("LocalTransport", () => {
       expect(localTransport$.value).toBe(null);
       await flushPromises();
       expect(localTransport$.value).toStrictEqual({
-        livekit_alias: "!example_room_id",
+        transport: {
-        livekit_service_url: "https://lk.example.org",
+          livekit_alias: "!example_room_id",
-        type: "livekit",
+          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",
+        },
       });
     });
     it("supports getting transport via backend", async () => {
@@ -191,9 +305,17 @@ describe("LocalTransport", () => {
       expect(localTransport$.value).toBe(null);
       await flushPromises();
       expect(localTransport$.value).toStrictEqual({
-        livekit_alias: "!example_room_id",
+        transport: {
-        livekit_service_url: "https://lk.example.org",
+          livekit_alias: "!example_room_id",
-        type: "livekit",
+          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",
+        },
       });
     });
     it("fails fast if the openID request fails for backend config", async () => {
@@ -222,9 +344,17 @@ describe("LocalTransport", () => {
       expect(localTransport$.value).toBe(null);
       await flushPromises();
       expect(localTransport$.value).toStrictEqual({
-        livekit_alias: "!example_room_id",
+        transport: {
-        livekit_service_url: "https://lk.example.org",
+          livekit_alias: "!example_room_id",
-        type: "livekit",
+          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",
+        },
       });
       expect(fetchMock.done()).toEqual(true);
     });
@@ -248,11 +378,15 @@ describe("LocalTransport", () => {
     it("throws if no options are available", async () => {
       const localTransport$ = createLocalTransport$({
         scope,
+        ownMembershipIdentity: ownMemberMock,
         roomId: "!example_room_id",
         useOldestMember$: constant(false),
+        forceJwtEndpoint$: constant(JwtEndpointVersion.Legacy),
+        delayId$: constant(null),
         memberships$: constant(new Epoch<CallMembership[]>([])),
         client: {
           getDomain: () => "",
+          baseUrl: "https://example.org",
           // eslint-disable-next-line @typescript-eslint/naming-convention
           _unstable_getRTCTransports: async () => Promise.resolve([]),
           // These won't be called in this error path but satisfy the type

src/state/CallViewModel/localMember/LocalTransport.ts

@@ -23,6 +23,7 @@ import {
 } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import { AutoDiscovery } from "matrix-js-sdk/lib/autodiscovery";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Epoch, type ObservableScope } from "../../ObservableScope.ts";
@@ -30,9 +31,11 @@ import { Config } from "../../../config/Config.ts";
 import {
   FailToGetOpenIdToken,
   MatrixRTCTransportMissingError,
+  NoMatrix2AuthorizationService,
 } from "../../../utils/errors.ts";
 import {
   getSFUConfigWithOpenID,
+  type SFUConfig,
   type OpenIDClientParts,
 } from "../../../livekit/openIDSFU.ts";
 import { areLivekitTransportsEqual } from "../remoteMembers/MatrixLivekitMembers.ts";
@@ -47,11 +50,32 @@ const logger = rootLogger.getChild("[LocalTransport]");
  */
 interface Props {
   scope: ObservableScope;
+  ownMembershipIdentity: CallMembershipIdentityParts;
   memberships$: Behavior<Epoch<CallMembership[]>>;
-  client: Pick<MatrixClient, "getDomain" | "_unstable_getRTCTransports"> &
+  client: Pick<
+    MatrixClient,
+    "getDomain" | "baseUrl" | "_unstable_getRTCTransports"
+  > &
     OpenIDClientParts;
   roomId: string;
   useOldestMember$: Behavior<boolean>;
+  forceJwtEndpoint$: Behavior<JwtEndpointVersion>;
+  delayId$: Behavior<string | null>;
+}
+
+export enum JwtEndpointVersion {
+  Legacy = "legacy",
+  Matrix_2_0 = "matrix_2_0",
+}
+
+export interface LocalTransportWithSFUConfig {
+  transport: LivekitTransport;
+  sfuConfig: SFUConfig;
+}
+export function isLocalTransportWithSFUConfig(
+  obj: LivekitTransport | LocalTransportWithSFUConfig,
+): obj is LocalTransportWithSFUConfig {
+  return "transport" in obj && "sfuConfig" in obj;
 }
 
 /**
@@ -61,26 +85,53 @@ interface Props {
  * @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.
+ * 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.
  * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
  */
 export const createLocalTransport$ = ({
   scope,
   memberships$,
+  ownMembershipIdentity,
   client,
   roomId,
   useOldestMember$,
-}: Props): Behavior<LivekitTransport | null> => {
+  forceJwtEndpoint$,
+  delayId$,
+}: Props): Behavior<LocalTransportWithSFUConfig | null> => {
   /**
    * The transport over which we should be actively publishing our media.
    * undefined when not joined.
    */
   const oldestMemberTransport$ = scope.behavior(
-    memberships$.pipe(
+    combineLatest([memberships$]).pipe(
-      map(
+      map(([memberships]) => {
-        (memberships) =>
+        const oldestMember = memberships.value[0];
-          memberships.value[0]?.getTransport(memberships.value[0]) ?? null,
+        const transport = oldestMember?.getTransport(memberships.value[0]);
-      ),
+        if (!transport) return null;
+        return transport;
+      }),
       first((t) => t != null && isLivekitTransport(t)),
+      switchMap((transport) => {
+        // Get the open jwt token to connect to the sfu
+        const computeLocalTransportWithSFUConfig =
+          async (): Promise<LocalTransportWithSFUConfig> => {
+            return {
+              transport,
+              sfuConfig: await getSFUConfigWithOpenID(
+                client,
+                ownMembershipIdentity,
+                transport.livekit_service_url,
+                roomId,
+                { forceJwtEndpoint: JwtEndpointVersion.Legacy },
+                logger,
+              ),
+            };
+          };
+        return from(computeLocalTransportWithSFUConfig());
+      }),
     ),
     null,
   );
@@ -91,9 +142,30 @@ export const createLocalTransport$ = ({
    *
    * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
    */
-  const preferredTransport$: Behavior<LivekitTransport | null> = scope.behavior(
+  const preferredTransport$ = scope.behavior(
-    customLivekitUrl.value$.pipe(
+    // preferredTransport$ (used for multi sfu) needs to know if we are using the old or new
-      switchMap((customUrl) => from(makeTransport(client, roomId, customUrl))),
+    // 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$]).pipe(
+      switchMap(([customUrl, delayId, forceEndpoint]) => {
+        logger.info(
+          "Creating preferred transport based on: ",
+          customUrl,
+          delayId,
+          forceEndpoint,
+        );
+        return from(
+          makeTransport(
+            client,
+            ownMembershipIdentity,
+            roomId,
+            customUrl,
+            forceEndpoint,
+            delayId ?? undefined,
+          ),
+        );
+      }),
     ),
     null,
   );
@@ -112,7 +184,9 @@ export const createLocalTransport$ = ({
           ? (oldestMemberTransport ?? preferredTransport)
           : preferredTransport,
       ),
-      distinctUntilChanged(areLivekitTransportsEqual),
+      distinctUntilChanged((t1, t2) =>
+        areLivekitTransportsEqual(t1?.transport ?? null, t2?.transport ?? null),
+      ),
     ),
   );
 };
@@ -124,25 +198,63 @@ const FOCI_WK_KEY = "org.matrix.msc4143.rtc_foci";
  * validating auth against the service to ensure it's correct.
  * Prefers in order:
  *
+
  * 1. The `urlFromDevSettings` value. If this cannot be validated, the function will throw.
  * 2. The transports returned via the homeserver.
  * 3. The transports returned via .well-known.
  * 4. The transport configured in Element Call's config.
  *
  * @param client The authenticated Matrix client for the current user
+ * @param membership The membership identity of the user.
  * @param roomId The ID of the room to be connected to.
  * @param urlFromDevSettings Override URL provided by the user's local config.
+ * @param forceJwtEndpoint Whether to force a specific JWT endpoint
+ *  - `Legacy` / `Matrix_2_0`
+ *  - `get_token` / `sfu/get`
+ *  -  not hashing / hashing the backendIdentity
+ * @param delayId the delay id passed to the jwt service.
+ *
  * @returns A fully validated transport config.
  * @throws MatrixRTCTransportMissingError | FailToGetOpenIdToken
  */
 async function makeTransport(
-  client: Pick<MatrixClient, "getDomain" | "_unstable_getRTCTransports"> &
+  client: Pick<
+    MatrixClient,
+    "getDomain" | "baseUrl" | "_unstable_getRTCTransports"
+  > &
     OpenIDClientParts,
+  membership: CallMembershipIdentityParts,
   roomId: string,
   urlFromDevSettings: string | null,
-): Promise<LivekitTransport> {
+  forceJwtEndpoint: JwtEndpointVersion,
+  delayId?: string,
+): Promise<LocalTransportWithSFUConfig> {
   logger.trace("Searching for a preferred transport");
 
+  async function doOpenIdAndJWTFromUrl(
+    url: string,
+  ): Promise<LocalTransportWithSFUConfig> {
+    const sfuConfig = await getSFUConfigWithOpenID(
+      client,
+      membership,
+      url,
+      roomId,
+      {
+        forceJwtEndpoint: forceJwtEndpoint,
+        delayEndpointBaseUrl: client.baseUrl,
+        delayId,
+      },
+      logger,
+    );
+    return {
+      transport: {
+        type: "livekit",
+        livekit_service_url: url,
+        livekit_alias: sfuConfig.livekitAlias,
+      },
+      sfuConfig,
+    };
+  }
   // We will call `getSFUConfigWithOpenID` once per transport here as it's our
   // only mechanism of valiation. This means we will also ask the
   // homeserver for a OpenID token a few times. Since OpenID tokens are single
@@ -153,39 +265,29 @@ async function makeTransport(
 
   // DEVTOOL: Highest priority: Load from devtool setting
   if (urlFromDevSettings !== null) {
-    logger.info("Using LiveKit transport from dev tools: ", urlFromDevSettings);
     // Validate that the SFU is up. Otherwise, we want to fail on this
     // as we don't permit other SFUs.
-    const config = await getSFUConfigWithOpenID(
+    // This will call the jwt/sfu/get endpoint to pre create the livekit room.
-      client,
+    logger.info("Using LiveKit transport from dev tools: ", urlFromDevSettings);
-      urlFromDevSettings,
+    return await doOpenIdAndJWTFromUrl(urlFromDevSettings);
-      roomId,
-    );
-    return {
-      type: "livekit",
-      livekit_service_url: urlFromDevSettings,
-      livekit_alias: config.livekitAlias,
-    };
   }
 
   async function getFirstUsableTransport(
     transports: Transport[],
-  ): Promise<LivekitTransport | null> {
+  ): Promise<LocalTransportWithSFUConfig | null> {
     for (const potentialTransport of transports) {
       if (isLivekitTransportConfig(potentialTransport)) {
         try {
-          const { livekitAlias } = await getSFUConfigWithOpenID(
+          // This will call the jwt/sfu/get endpoint to pre create the livekit room.
-            client,
+          return await doOpenIdAndJWTFromUrl(
             potentialTransport.livekit_service_url,
-            roomId,
           );
-          return {
-            ...potentialTransport,
-            livekit_alias: livekitAlias,
-          };
         } catch (ex) {
+          // Explictly throw these
           if (ex instanceof FailToGetOpenIdToken) {
-            // Explictly throw these
+            throw ex;
+          }
+          if (ex instanceof NoMatrix2AuthorizationService) {
             throw ex;
           }
           logger.debug(
@@ -245,18 +347,9 @@ async function makeTransport(
   const urlFromConf = Config.get().livekit?.livekit_service_url;
   if (urlFromConf) {
     try {
-      const { livekitAlias } = await getSFUConfigWithOpenID(
+      // This will call the jwt/sfu/get endpoint to pre create the livekit room.
-        client,
+      logger.info("Using config SFU", urlFromConf);
-        urlFromConf,
+      return await doOpenIdAndJWTFromUrl(urlFromConf);
-        roomId,
-      );
-      const selectedTransport: LivekitTransport = {
-        type: "livekit",
-        livekit_service_url: urlFromConf,
-        livekit_alias: livekitAlias,
-      };
-      logger.info("Using config SFU", selectedTransport);
-      return selectedTransport;
     } catch (ex) {
       if (ex instanceof FailToGetOpenIdToken) {
         throw ex;
@@ -265,5 +358,6 @@ async function makeTransport(
     }
   }
 
+  // If we do not have returned a transport by now we throw an error
   throw new MatrixRTCTransportMissingError(domain ?? "");
 }

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

@@ -26,8 +26,8 @@ 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 { LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import {
   Connection,
   ConnectionState,
@@ -40,7 +40,7 @@ import {
   FailToGetOpenIdToken,
 } from "../../../utils/errors.ts";
 import { testJWTToken } from "../../../utils/test-fixtures.ts";
-import { mockRemoteParticipant } from "../../../utils/test.ts";
+import { mockRemoteParticipant, ownMemberMock } from "../../../utils/test.ts";
 
 let testScope: ObservableScope;
 
@@ -114,6 +114,7 @@ function setupRemoteConnection(): Connection {
     client: client,
     transport: livekitFocus,
     scope: testScope,
+    ownMembershipIdentity: ownMemberMock,
     livekitRoomFactory: () => fakeLivekitRoom,
   };
 
@@ -155,6 +156,7 @@ describe("Start connection states", () => {
       client: client,
       transport: livekitFocus,
       scope: testScope,
+      ownMembershipIdentity: ownMemberMock,
       livekitRoomFactory: () => fakeLivekitRoom,
     };
     const connection = new Connection(opts, logger);
@@ -170,6 +172,7 @@ describe("Start connection states", () => {
       client: client,
       transport: livekitFocus,
       scope: testScope,
+      ownMembershipIdentity: ownMemberMock,
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 
@@ -220,6 +223,7 @@ describe("Start connection states", () => {
       client: client,
       transport: livekitFocus,
       scope: testScope,
+      ownMembershipIdentity: ownMemberMock,
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 
@@ -259,7 +263,7 @@ describe("Start connection states", () => {
       capturedState.cause instanceof Error
     ) {
       expect(capturedState.cause.message).toContain(
-        "SFU Config fetch failed with exception",
+        "SFU Config fetch failed with status code 500",
       );
       expect(connection.transport.livekit_alias).toEqual(
         livekitFocus.livekit_alias,
@@ -277,6 +281,7 @@ describe("Start connection states", () => {
       client: client,
       transport: livekitFocus,
       scope: testScope,
+      ownMembershipIdentity: ownMemberMock,
       livekitRoomFactory: () => fakeLivekitRoom,
     };
 

src/state/CallViewModel/remoteMembers/Connection.ts

@@ -18,6 +18,7 @@ import {
 import { type LivekitTransport } 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";
 
 import {
   getSFUConfigWithOpenID,
@@ -32,8 +33,21 @@ import {
   SFURoomCreationRestrictedError,
   UnknownCallError,
 } from "../../../utils/errors.ts";
+import { type JwtEndpointVersion } from "../localMember/LocalTransport.ts";
 
 export interface ConnectionOpts {
+  /**
+   * For the local transport we already do know the jwt token and url. We can reuse it.
+   * On top the local transport will send additional data to the jwt server to use delayed event delegation.
+   */
+  existingSFUConfig?: SFUConfig;
+  /**
+   * For local connections that use the oldest member pattern. here we have not prefetched the sfuConfig
+   * and hence we need to let the connection do the jwt token fetching.
+   */
+  forceJwtEndpoint?: JwtEndpointVersion;
+  /** The identity parts to use on this connection */
+  ownMembershipIdentity: CallMembershipIdentityParts;
   /** The media transport to connect to. */
   transport: LivekitTransport;
   /** The Matrix client to use for OpenID and SFU config requests. */
@@ -129,8 +143,10 @@ export class Connection {
     try {
       this._state$.next(ConnectionState.FetchingConfig);
       // We should already have this information after creating the localTransport.
-      // It would probably be better to forward this here.
+      // only call getSFUConfigWithOpenID for connections where we do not have a token yet. (existingJwtTokenData === undefined)
-      const { url, jwt } = await this.getSFUConfigWithOpenID();
+      const { url, jwt } =
+        this.existingSFUConfig ??
+        (await this.getSFUConfigForRemoteConnection());
       // If we were stopped while fetching the config, don't proceed to connect
       if (this.stopped) return;
 
@@ -186,11 +202,17 @@ export class Connection {
     }
   }
 
-  protected async getSFUConfigWithOpenID(): Promise<SFUConfig> {
+  protected async getSFUConfigForRemoteConnection(): Promise<SFUConfig> {
+    // This will only be called for sfu's where we do not publish ourselves.
+    // For the local connection we will use the existingJwtTokenData
     return await getSFUConfigWithOpenID(
       this.client,
+      this.ownMembershipIdentity,
       this.transport.livekit_service_url,
       this.transport.livekit_alias,
+      // dont pass any custom opts for the subscribe only connections
+      {},
+      this.logger,
     );
   }
 
@@ -212,7 +234,8 @@ export class Connection {
 
   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.
    *
@@ -221,6 +244,8 @@ export class Connection {
    * @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]");
     this.logger.info(
       `Creating new connection to ${opts.transport.livekit_service_url} ${opts.transport.livekit_alias}`,

src/state/CallViewModel/remoteMembers/ConnectionFactory.ts

@@ -5,7 +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 LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import {
   Room as LivekitRoom,
   type RoomOptions,
@@ -16,10 +15,15 @@ import {
 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 ObservableScope } from "../../ObservableScope.ts";
 import { Connection } from "./Connection.ts";
-import type { OpenIDClientParts } from "../../../livekit/openIDSFU.ts";
+import type {
+  OpenIDClientParts,
+  SFUConfig,
+} from "../../../livekit/openIDSFU.ts";
 import type { MediaDevices } from "../../MediaDevices.ts";
 import type { Behavior } from "../../Behavior.ts";
 import type { ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
@@ -28,9 +32,11 @@ import { defaultLiveKitOptions } from "../../../livekit/options.ts";
 // TODO evaluate if this should be done like the Publisher Factory
 export interface ConnectionFactory {
   createConnection(
-    transport: LivekitTransport,
     scope: ObservableScope,
+    transport: LivekitTransport,
+    ownMembershipIdentity: CallMembershipIdentityParts,
     logger: Logger,
+    sfuConfig?: SFUConfig,
   ): Connection;
 }
 
@@ -78,17 +84,30 @@ export class ECConnectionFactory implements ConnectionFactory {
     this.livekitRoomFactory = livekitRoomFactory ?? defaultFactory;
   }
 
+  /**
+   *
+   * @param scope The observable scope (used for clean-up)
+   * @param transport The transport to use for this connection.
+   * @param ownMembershipIdentity required to connect (using the jwt service) with the SFU.
+   * @param logger The logger instance to use for this connection.
+   * @param sfuConfig optional config in case we already have a token for this connection.
+   * @returns
+   */
   public createConnection(
-    transport: LivekitTransport,
     scope: ObservableScope,
+    transport: LivekitTransport,
+    ownMembershipIdentity: CallMembershipIdentityParts,
     logger: Logger,
+    sfuConfig?: SFUConfig,
   ): Connection {
     return new Connection(
       {
+        existingSFUConfig: sfuConfig,
         transport,
         client: this.client,
         scope: scope,
         livekitRoomFactory: this.livekitRoomFactory,
+        ownMembershipIdentity,
       },
       logger,
     );

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

@@ -18,9 +18,9 @@ import {
 } from "./ConnectionManager.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
 import { type Connection } from "./Connection.ts";
-import { withTestScheduler } from "../../../utils/test.ts";
+import { ownMemberMock, withTestScheduler } from "../../../utils/test.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
-import { type Behavior } from "../../Behavior.ts";
+import { constant, type Behavior } from "../../Behavior.ts";
 
 // Some test constants
 
@@ -49,7 +49,7 @@ beforeEach(() => {
   vi.mocked(fakeConnectionFactory).createConnection = vi
     .fn()
     .mockImplementation(
-      (transport: LivekitTransport, scope: ObservableScope) => {
+      (scope: ObservableScope, transport: LivekitTransport) => {
         const mockConnection = {
           transport,
           remoteParticipants$: new BehaviorSubject([]),
@@ -76,10 +76,12 @@ describe("connections$ stream", () => {
       const { connectionManagerData$ } = createConnectionManager$({
         scope: testScope,
         connectionFactory: fakeConnectionFactory,
-        inputTransports$: behavior("a", {
+        localTransport$: constant(null),
+        remoteTransports$: behavior("a", {
           a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -115,7 +117,8 @@ describe("connections$ stream", () => {
       const { connectionManagerData$ } = createConnectionManager$({
         scope: testScope,
         connectionFactory: fakeConnectionFactory,
-        inputTransports$: behavior("abcdef", {
+        localTransport$: constant(null),
+        remoteTransports$: behavior("abcdef", {
           a: new Epoch([TRANSPORT_1], 0),
           b: new Epoch([TRANSPORT_1], 1),
           c: new Epoch([TRANSPORT_1], 2),
@@ -124,6 +127,7 @@ describe("connections$ stream", () => {
           f: new Epoch([TRANSPORT_1, TRANSPORT_2], 5),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -160,12 +164,14 @@ describe("connections$ stream", () => {
       const { connectionManagerData$ } = createConnectionManager$({
         scope: testScope,
         connectionFactory: fakeConnectionFactory,
-        inputTransports$: behavior("abc", {
+        localTransport$: constant(null),
+        remoteTransports$: behavior("abc", {
           a: new Epoch([TRANSPORT_1], 0),
           b: new Epoch([TRANSPORT_1, TRANSPORT_2], 1),
           c: new Epoch([TRANSPORT_1], 2),
         }),
         logger: logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(
@@ -223,7 +229,7 @@ describe("connectionManagerData$ stream", () => {
     vi.mocked(fakeConnectionFactory).createConnection = vi
       .fn()
       .mockImplementation(
-        (transport: LivekitTransport, scope: ObservableScope) => {
+        (scope: ObservableScope, transport: LivekitTransport) => {
           const fakeRemoteParticipants$ = new BehaviorSubject<
             RemoteParticipant[]
           >([]);
@@ -275,10 +281,12 @@ describe("connectionManagerData$ stream", () => {
       const { connectionManagerData$ } = createConnectionManager$({
         scope: testScope,
         connectionFactory: fakeConnectionFactory,
-        inputTransports$: behavior("a", {
+        localTransport$: constant(null),
+        remoteTransports$: behavior("a", {
           a: new Epoch([TRANSPORT_1, TRANSPORT_2], 0),
         }),
         logger,
+        ownMembershipIdentity: ownMemberMock,
       });
 
       expectObservable(connectionManagerData$).toBe("abcd", {

src/state/CallViewModel/remoteMembers/ConnectionManager.ts

@@ -7,9 +7,10 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
-import { combineLatest, map, of, switchMap, tap } from "rxjs";
+import { combineLatest, map, of, switchMap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type RemoteParticipant } from "livekit-client";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import { type Behavior } from "../../Behavior.ts";
 import { type Connection } from "./Connection.ts";
@@ -17,6 +18,11 @@ import { Epoch, type ObservableScope } from "../../ObservableScope.ts";
 import { generateItemsWithEpoch } from "../../../utils/observable.ts";
 import { areLivekitTransportsEqual } from "./MatrixLivekitMembers.ts";
 import { type ConnectionFactory } from "./ConnectionFactory.ts";
+import {
+  isLocalTransportWithSFUConfig,
+  type LocalTransportWithSFUConfig,
+} from "../localMember/LocalTransport.ts";
+import { type SFUConfig } from "../../../livekit/openIDSFU.ts";
 
 export class ConnectionManagerData {
   private readonly store: Map<
@@ -65,8 +71,11 @@ export class ConnectionManagerData {
 interface Props {
   scope: ObservableScope;
   connectionFactory: ConnectionFactory;
-  inputTransports$: Behavior<Epoch<LivekitTransport[]>>;
+  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
+  remoteTransports$: Behavior<Epoch<LivekitTransport[]>>;
+
   logger: Logger;
+  ownMembershipIdentity: CallMembershipIdentityParts;
 }
 
 // TODO - write test for scopes (do we really need to bind scope)
@@ -79,8 +88,12 @@ 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.inputTransports$ - A list of Behaviors each containing a LIST of LivekitTransport.
+ * @param props.localTransport$ - The local transport to use. (deduplicated with remoteTransports$)
- * @param props.logger - The logger to use
+ * @param props.remoteTransports$ - All other transports. The connection manager will create connections for each transport. (deduplicated with localTransport$)
+ * @param props.ownMembershipIdentity - The own membership identity to use.
+ * @param props.logger - The logger to use.
+
+ *
  *   Each of these behaviors can be interpreted as subscribed list of transports.
  *
  *   Using `registerTransports` independent external modules can control what connections
@@ -93,8 +106,10 @@ export interface IConnectionManager {
 export function createConnectionManager$({
   scope,
   connectionFactory,
-  inputTransports$,
+  localTransport$,
+  remoteTransports$,
   logger: parentLogger,
+  ownMembershipIdentity,
 }: Props): IConnectionManager {
   const logger = parentLogger.getChild("[ConnectionManager]");
   // TODO logger: only construct one logger from the client and make it compatible via a EC specific sing
@@ -107,12 +122,33 @@ export function createConnectionManager$({
    * It is build based on the list of subscribed transports (`transportsSubscriptions$`).
    * externally this is modified via `registerTransports()`.
    */
-  const transports$ = scope.behavior(
+  const localAndRemoteTransports$: Behavior<
-    inputTransports$.pipe(
+    Epoch<(LivekitTransport | LocalTransportWithSFUConfig)[]>
-      map((transports) => transports.mapInner(removeDuplicateTransports)),
+  > = scope.behavior(
-      tap(({ value: transports }) => {
+    combineLatest([remoteTransports$, localTransport$]).pipe(
-        logger.trace(
+      // Combine local and remote transports into one transport array
-          `Managing transports: ${transports.map((t) => t.livekit_service_url).join(", ")}`,
+      // and set the forceOldJwtEndpoint property on the local transport
+      map(([remoteTransports, localTransport]) => {
+        let localTransportAsArray: LocalTransportWithSFUConfig[] = [];
+        if (localTransport) {
+          localTransportAsArray = [localTransport];
+        }
+        const dedupedRemote = removeDuplicateTransports(remoteTransports.value);
+        const remoteWithoutLocal = dedupedRemote.filter(
+          (transport) =>
+            !localTransportAsArray.find((l) =>
+              areLivekitTransportsEqual(l.transport, transport),
+            ),
+        );
+        logger.debug(
+          "remoteWithoutLocal",
+          remoteWithoutLocal,
+          "localTransportAsArray",
+          localTransportAsArray,
+        );
+        return new Epoch(
+          [...localTransportAsArray, ...remoteWithoutLocal],
+          remoteTransports.epoch,
         );
       }),
     ),
@@ -122,25 +158,51 @@ export function createConnectionManager$({
    * Connections for each transport in use by one or more session members.
    */
   const connections$ = scope.behavior(
-    transports$.pipe(
+    localAndRemoteTransports$.pipe(
       generateItemsWithEpoch(
         function* (transports) {
-          for (const transport of transports)
+          for (const transportWithOrWithoutSfuConfig of transports) {
-            yield {
+            if (
-              keys: [transport.livekit_service_url, transport.livekit_alias],
+              isLocalTransportWithSFUConfig(transportWithOrWithoutSfuConfig)
-              data: undefined,
+            ) {
-            };
+              // This is the local transport only the `LocalTransportWithSFUConfig` has a `sfuConfig` field
+              const { transport, sfuConfig } = transportWithOrWithoutSfuConfig;
+              yield {
+                keys: [
+                  transport.livekit_service_url,
+                  transport.livekit_alias,
+                  sfuConfig,
+                ],
+                data: undefined,
+              };
+            } else {
+              const transport = transportWithOrWithoutSfuConfig;
+              yield {
+                keys: [
+                  transport.livekit_service_url,
+                  transport.livekit_alias,
+                  undefined as undefined | SFUConfig,
+                ],
+                data: undefined,
+              };
+            }
+          }
         },
-        (scope, _data$, serviceUrl, alias) => {
+        (scope, _data$, serviceUrl, alias, sfuConfig) => {
-          logger.debug(`Creating connection to ${serviceUrl} (${alias})`);
+          logger.debug(
+            `Creating connection to ${serviceUrl} (${alias}, withSfuConfig (local connection?): ${JSON.stringify(sfuConfig) ?? "no config->remote connection"})`,
+          );
+
           const connection = connectionFactory.createConnection(
+            scope,
             {
               type: "livekit",
               livekit_service_url: serviceUrl,
               livekit_alias: alias,
             },
-            scope,
+            ownMembershipIdentity,
             logger,
+            sfuConfig,
           );
           // Start the connection immediately
           // Use connection state to track connection progress
@@ -190,18 +252,18 @@ export function createConnectionManager$({
         );
       }),
     ),
-    new Epoch(new ConnectionManagerData()),
+    new Epoch(new ConnectionManagerData(), -1),
   );
 
   return { connectionManagerData$ };
 }
 
-function removeDuplicateTransports(
+function removeDuplicateTransports<T extends LivekitTransport>(
-  transports: LivekitTransport[],
+  transports: T[],
-): LivekitTransport[] {
+): T[] {
   return transports.reduce((acc, transport) => {
     if (!acc.some((t) => areLivekitTransportsEqual(t, transport)))
       acc.push(transport);
     return acc;
-  }, [] as LivekitTransport[]);
+  }, [] as T[]);
 }

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

@@ -15,7 +15,11 @@ import EventEmitter from "events";
 import { ObservableScope } from "../../ObservableScope.ts";
 import { ECConnectionFactory } from "./ConnectionFactory.ts";
 import type { OpenIDClientParts } from "../../../livekit/openIDSFU.ts";
-import { exampleTransport, mockMediaDevices } from "../../../utils/test.ts";
+import {
+  exampleTransport,
+  mockMediaDevices,
+  ownMemberMock,
+} from "../../../utils/test.ts";
 import type { ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
 import { constant } from "../../Behavior";
 
@@ -72,7 +76,12 @@ describe("ECConnectionFactory - Audio inputs options", () => {
         echo,
         noise,
       );
-      ecConnectionFactory.createConnection(exampleTransport, testScope, logger);
+      ecConnectionFactory.createConnection(
+        testScope,
+        exampleTransport,
+        ownMemberMock,
+        logger,
+      );
 
       // Check if Room was constructed with expected options
       expect(RoomConstructor).toHaveBeenCalledWith(
@@ -113,7 +122,12 @@ describe("ECConnectionFactory - ControlledAudioDevice", () => {
         false,
         false,
       );
-      ecConnectionFactory.createConnection(exampleTransport, testScope, logger);
+      ecConnectionFactory.createConnection(
+        testScope,
+        exampleTransport,
+        ownMemberMock,
+        logger,
+      );
 
       // Check if Room was constructed with expected options
       expect(RoomConstructor).toHaveBeenCalledWith(

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

@@ -10,8 +10,7 @@ import {
   type CallMembership,
   type LivekitTransport,
 } from "matrix-js-sdk/lib/matrixrtc";
-import { getParticipantId } from "matrix-js-sdk/lib/matrixrtc/utils";
+import { BehaviorSubject, combineLatest, map, type Observable } from "rxjs";
-import { combineLatest, map, type Observable } from "rxjs";
 
 import { type IConnectionManager } from "./ConnectionManager.ts";
 import {
@@ -26,14 +25,18 @@ import {
 } from "../../ObservableScope.ts";
 import { ConnectionManagerData } from "./ConnectionManager.ts";
 import {
-  mockCallMembership,
+  flushPromises,
+  mockRtcMembership,
   mockRemoteParticipant,
-  withTestScheduler,
 } from "../../../utils/test.ts";
 import { type Connection } from "./Connection.ts";
+import { constant } from "../../Behavior.ts";
 
 let testScope: ObservableScope;
 
+const fallbackMemberId = (userId: string, deviceId: string): string =>
+  `${userId}:${deviceId}`;
+
 const transportA: LivekitTransport = {
   type: "livekit",
   livekit_service_url: "https://lk.example.org",
@@ -46,16 +49,12 @@ const transportB: LivekitTransport = {
   livekit_alias: "!alias:sample.com",
 };
 
-const bobMembership = mockCallMembership(
+const bobMembership = mockRtcMembership("@bob:example.org", "DEV000", {
-  "@bob:example.org",
+  fociPreferred: [transportA],
-  "DEV000",
+});
-  transportA,
+const carlMembership = mockRtcMembership("@carl:sample.com", "DEV111", {
-);
+  fociPreferred: [transportB],
-const carlMembership = mockCallMembership(
+});
-  "@carl:sample.com",
-  "DEV111",
-  transportB,
-);
 
 beforeEach(() => {
   testScope = new ObservableScope();
@@ -76,52 +75,41 @@ function epochMeWith$<T, U>(
   );
 }
 
-test("should signal participant not yet connected to livekit", () => {
+test("should signal participant not yet connected to livekit", async () => {
-  withTestScheduler(({ behavior, expectObservable }) => {
+  const mockedMemberships$ = new BehaviorSubject([bobMembership]);
-    const { memberships$, membershipsWithTransport$ } = fromMemberships$(
+  const mockConnectionManagerData$ = new BehaviorSubject(
-      behavior("a", {
+    new ConnectionManagerData(),
-        a: [bobMembership],
+  );
-      }),
+  const { memberships$, membershipsWithTransport$ } =
-    );
+    createEpochedMemberships$(mockedMemberships$);
 
-    const connectionManagerData$ = epochMeWith$(
+  const connectionManagerData$ = epochMeWith$(
-      memberships$,
+    memberships$,
-      behavior("a", {
+    mockConnectionManagerData$,
-        a: new ConnectionManagerData(),
+  );
-      }),
-    );
 
-    const matrixLivekitMembers$ = createMatrixLivekitMembers$({
+  const matrixLivekitMember$ = createMatrixLivekitMembers$({
-      scope: testScope,
+    scope: testScope,
-      membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+    membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
-      connectionManager: {
+    connectionManager: {
-        connectionManagerData$: connectionManagerData$,
+      connectionManagerData$: connectionManagerData$,
-      } as unknown as IConnectionManager,
+    } as unknown as IConnectionManager,
-    });
-
-    expectObservable(matrixLivekitMembers$.pipe(map((e) => e.value))).toBe(
-      "a",
-      {
-        a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
-          expect(data.length).toEqual(1);
-          expectObservable(data[0].membership$).toBe("a", {
-            a: bobMembership,
-          });
-          expectObservable(data[0].participant.value$).toBe("a", {
-            a: null,
-          });
-          expectObservable(data[0].connection$).toBe("a", {
-            a: null,
-          });
-          return true;
-        }),
-      },
-    );
   });
+
+  await flushPromises();
+  expect(matrixLivekitMember$.value.value).toSatisfy(
+    (data: RemoteMatrixLivekitMember[]) => {
+      expect(data.length).toEqual(1);
+      expect(data[0].membership$.value).toBe(bobMembership);
+      expect(data[0].participant.value$.value).toBe(null);
+      expect(data[0].connection$.value).toBe(null);
+      return true;
+    },
+  );
 });
 
 // Helper to create epoch'ed memberships$ and membershipsWithTransport$ from memberships observable.
-function fromMemberships$(m$: Observable<CallMembership[]>): {
+function createEpochedMemberships$(m$: Observable<CallMembership[]>): {
   memberships$: Observable<Epoch<CallMembership[]>>;
   membershipsWithTransport$: Observable<
     Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
@@ -146,32 +134,115 @@ function fromMemberships$(m$: Observable<CallMembership[]>): {
   };
 }
 
-test("should signal participant on a connection that is publishing", () => {
+test("should signal participant on a connection that is publishing", async () => {
-  withTestScheduler(({ behavior, expectObservable }) => {
+  const bobParticipantId = fallbackMemberId(
-    const bobParticipantId = getParticipantId(
+    bobMembership.userId,
+    bobMembership.deviceId,
+  );
+
+  const { memberships$, membershipsWithTransport$ } = createEpochedMemberships$(
+    constant([bobMembership]),
+  );
+
+  const connection = {
+    transport: bobMembership.getTransport(bobMembership),
+  } as unknown as Connection;
+  const dataWithPublisher = new ConnectionManagerData();
+  dataWithPublisher.add(connection, [
+    mockRemoteParticipant({ identity: bobParticipantId }),
+  ]);
+
+  const connectionManagerData$ = epochMeWith$(
+    memberships$,
+    constant(dataWithPublisher),
+  );
+
+  const matrixLivekitMember$ = createMatrixLivekitMembers$({
+    scope: testScope,
+    membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+    connectionManager: {
+      connectionManagerData$: connectionManagerData$,
+    } as unknown as IConnectionManager,
+  });
+
+  await flushPromises();
+  expect(matrixLivekitMember$.value.value).toSatisfy(
+    (data: RemoteMatrixLivekitMember[]) => {
+      expect(data.length).toEqual(1);
+      expect(data[0].membership$.value).toBe(bobMembership);
+      expect(data[0].participant.value$.value).toSatisfy((participant) => {
+        expect(participant).toBeDefined();
+        expect(participant!.identity).toEqual(bobParticipantId);
+        return true;
+      });
+      expect(data[0].connection$.value).toBe(connection);
+      return true;
+    },
+  );
+});
+
+test("should signal participant on a connection that is not publishing", async () => {
+  const { memberships$, membershipsWithTransport$ } = createEpochedMemberships$(
+    constant([bobMembership]),
+  );
+
+  const connection = {
+    transport: bobMembership.getTransport(bobMembership),
+  } as unknown as Connection;
+  const dataWithPublisher = new ConnectionManagerData();
+  dataWithPublisher.add(connection, []);
+
+  const connectionManagerData$ = epochMeWith$(
+    memberships$,
+    constant(dataWithPublisher),
+  );
+
+  const matrixLivekitMember$ = createMatrixLivekitMembers$({
+    scope: testScope,
+    membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+    connectionManager: {
+      connectionManagerData$: connectionManagerData$,
+    } as unknown as IConnectionManager,
+  });
+  await flushPromises();
+  expect(matrixLivekitMember$.value.value).toSatisfy(
+    (data: RemoteMatrixLivekitMember[]) => {
+      expect(data.length).toEqual(1);
+      expect(data[0].membership$.value).toBe(bobMembership);
+      expect(data[0].participant.value$.value).toBe(null);
+      expect(data[0].connection$.value).toBe(connection);
+      return true;
+    },
+  );
+});
+
+describe("Publication edge case", () => {
+  test("bob is publishing in several connections", async () => {
+    const { memberships$, membershipsWithTransport$ } =
+      createEpochedMemberships$(constant([bobMembership, carlMembership]));
+
+    const connectionWithPublisher = new ConnectionManagerData();
+    const bobParticipantId = fallbackMemberId(
       bobMembership.userId,
       bobMembership.deviceId,
     );
-
+    const connectionA = {
-    const { memberships$, membershipsWithTransport$ } = fromMemberships$(
+      transport: transportA,
-      behavior("a", {
-        a: [bobMembership],
-      }),
-    );
-
-    const connection = {
-      transport: bobMembership.getTransport(bobMembership),
     } as unknown as Connection;
-    const dataWithPublisher = new ConnectionManagerData();
+    const connectionB = {
-    dataWithPublisher.add(connection, [
+      transport: transportB,
+    } as unknown as Connection;
+
+    connectionWithPublisher.add(connectionA, [
+      mockRemoteParticipant({ identity: bobParticipantId }),
+    ]);
+    connectionWithPublisher.add(connectionB, [
       mockRemoteParticipant({ identity: bobParticipantId }),
     ]);
 
     const connectionManagerData$ = epochMeWith$(
       memberships$,
-      behavior("a", {
+      constant(connectionWithPublisher),
-        a: dataWithPublisher,
-      }),
     );
 
     const matrixLivekitMembers$ = createMatrixLivekitMembers$({
@@ -181,213 +252,73 @@ test("should signal participant on a connection that is publishing", () => {
         connectionManagerData$: connectionManagerData$,
       } as unknown as IConnectionManager,
     });
-
+    await flushPromises();
-    expectObservable(matrixLivekitMembers$.pipe(map((e) => e.value))).toBe(
+    expect(matrixLivekitMembers$.value.value).toSatisfy(
-      "a",
+      (data: RemoteMatrixLivekitMember[]) => {
-      {
+        expect(data.length).toEqual(2);
-        a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
+        expect(data[0].membership$.value).toBe(bobMembership);
-          expect(data.length).toEqual(1);
+        expect(data[0].connection$.value).toBe(connectionA);
-          expectObservable(data[0].membership$).toBe("a", {
+        expect(data[0].participant.value$.value).toSatisfy((participant) => {
-            a: bobMembership,
+          expect(participant).toBeDefined();
-          });
+          expect(participant!.identity).toEqual(bobParticipantId);
-          expectObservable(data[0].participant.value$).toBe("a", {
-            a: expect.toSatisfy((participant) => {
-              expect(participant).toBeDefined();
-              expect(participant!.identity).toEqual(bobParticipantId);
-              return true;
-            }),
-          });
-          expectObservable(data[0].connection$).toBe("a", {
-            a: connection,
-          });
           return true;
-        }),
+        });
+
+        return true;
       },
     );
   });
 });
 
-test("should signal participant on a connection that is not publishing", () => {
+test("bob is publishing in the wrong connection", async () => {
-  withTestScheduler(({ behavior, expectObservable }) => {
+  const mockedMemberships$ = new BehaviorSubject([
-    const { memberships$, membershipsWithTransport$ } = fromMemberships$(
+    bobMembership,
-      behavior("a", {
+    carlMembership,
-        a: [bobMembership],
+  ]);
-      }),
-    );
 
-    const connection = {
+  const { memberships$, membershipsWithTransport$ } =
-      transport: bobMembership.getTransport(bobMembership),
+    createEpochedMemberships$(mockedMemberships$);
-    } as unknown as Connection;
-    const dataWithPublisher = new ConnectionManagerData();
-    dataWithPublisher.add(connection, []);
 
-    const connectionManagerData$ = epochMeWith$(
+  const connectionWithPublisher = new ConnectionManagerData();
-      memberships$,
-      behavior("a", {
-        a: dataWithPublisher,
-      }),
-    );
 
-    const matrixLivekitMembers$ = createMatrixLivekitMembers$({
+  const bobParticipantId = fallbackMemberId(
-      scope: testScope,
+    bobMembership.userId,
-      membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
+    bobMembership.deviceId,
-      connectionManager: {
+  );
-        connectionManagerData$: connectionManagerData$,
+  const connectionA = { transport: transportA } as unknown as Connection;
-      } as unknown as IConnectionManager,
+  const connectionB = { transport: transportB } as unknown as Connection;
-    });
 
-    expectObservable(matrixLivekitMembers$.pipe(map((e) => e.value))).toBe(
+  // Bob is not publishing on A
-      "a",
+  connectionWithPublisher.add(connectionA, []);
-      {
+  // Bob is publishing on B but his membership says A
-        a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
+  connectionWithPublisher.add(connectionB, [
-          expect(data.length).toEqual(1);
+    mockRemoteParticipant({ identity: bobParticipantId }),
-          expectObservable(data[0].membership$).toBe("a", {
+  ]);
-            a: bobMembership,
+
-          });
+  const connectionsWithPublisher$ = new BehaviorSubject(
-          expectObservable(data[0].participant.value$).toBe("a", {
+    connectionWithPublisher,
-            a: null,
+  );
-          });
+  const connectionManagerData$ = epochMeWith$(
-          expectObservable(data[0].connection$).toBe("a", {
+    memberships$,
-            a: connection,
+    connectionsWithPublisher$,
-          });
+  );
-          return true;
+
-        }),
+  const matrixLivekitMember$ = createMatrixLivekitMembers$({
-      },
+    scope: testScope,
-    );
+    membershipsWithTransport$: testScope.behavior(membershipsWithTransport$),
-  });
+    connectionManager: {
-});
+      connectionManagerData$: connectionManagerData$,
-
+    } as unknown as IConnectionManager,
-describe("Publication edge case", () => {
-  test("bob is publishing in several connections", () => {
-    withTestScheduler(({ behavior, expectObservable }) => {
-      const { memberships$, membershipsWithTransport$ } = fromMemberships$(
-        behavior("a", {
-          a: [bobMembership, carlMembership],
-        }),
-      );
-
-      const connectionWithPublisher = new ConnectionManagerData();
-      const bobParticipantId = getParticipantId(
-        bobMembership.userId,
-        bobMembership.deviceId,
-      );
-      const connectionA = {
-        transport: transportA,
-      } as unknown as Connection;
-      const connectionB = {
-        transport: transportB,
-      } as unknown as Connection;
-
-      connectionWithPublisher.add(connectionA, [
-        mockRemoteParticipant({ identity: bobParticipantId }),
-      ]);
-      connectionWithPublisher.add(connectionB, [
-        mockRemoteParticipant({ identity: bobParticipantId }),
-      ]);
-
-      const connectionManagerData$ = epochMeWith$(
-        memberships$,
-        behavior("a", {
-          a: connectionWithPublisher,
-        }),
-      );
-
-      const matrixLivekitMembers$ = createMatrixLivekitMembers$({
-        scope: testScope,
-        membershipsWithTransport$: testScope.behavior(
-          membershipsWithTransport$,
-        ),
-        connectionManager: {
-          connectionManagerData$: connectionManagerData$,
-        } as unknown as IConnectionManager,
-      });
-
-      expectObservable(matrixLivekitMembers$.pipe(map((e) => e.value))).toBe(
-        "a",
-        {
-          a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
-            expect(data.length).toEqual(2);
-            expectObservable(data[0].membership$).toBe("a", {
-              a: bobMembership,
-            });
-            expectObservable(data[0].connection$).toBe("a", {
-              // The real connection should be from transportA as per the membership
-              a: connectionA,
-            });
-            expectObservable(data[0].participant.value$).toBe("a", {
-              a: expect.toSatisfy((participant) => {
-                expect(participant).toBeDefined();
-                expect(participant!.identity).toEqual(bobParticipantId);
-                return true;
-              }),
-            });
-            return true;
-          }),
-        },
-      );
-    });
-  });
-
-  test("bob is publishing in the wrong connection", () => {
-    withTestScheduler(({ behavior, expectObservable }) => {
-      const { memberships$, membershipsWithTransport$ } = fromMemberships$(
-        behavior("a", {
-          a: [bobMembership, carlMembership],
-        }),
-      );
-
-      const connectionWithPublisher = new ConnectionManagerData();
-      const bobParticipantId = getParticipantId(
-        bobMembership.userId,
-        bobMembership.deviceId,
-      );
-      const connectionA = { transport: transportA } as unknown as Connection;
-      const connectionB = { transport: transportB } as unknown as Connection;
-
-      // Bob is not publishing on A
-      connectionWithPublisher.add(connectionA, []);
-      // Bob is publishing on B but his membership says A
-      connectionWithPublisher.add(connectionB, [
-        mockRemoteParticipant({ identity: bobParticipantId }),
-      ]);
-
-      const connectionManagerData$ = epochMeWith$(
-        memberships$,
-        behavior("a", {
-          a: connectionWithPublisher,
-        }),
-      );
-
-      const matrixLivekitMembers$ = createMatrixLivekitMembers$({
-        scope: testScope,
-        membershipsWithTransport$: testScope.behavior(
-          membershipsWithTransport$,
-        ),
-        connectionManager: {
-          connectionManagerData$: connectionManagerData$,
-        } as unknown as IConnectionManager,
-      });
-
-      expectObservable(matrixLivekitMembers$.pipe(map((e) => e.value))).toBe(
-        "a",
-        {
-          a: expect.toSatisfy((data: RemoteMatrixLivekitMember[]) => {
-            expect(data.length).toEqual(2);
-            expectObservable(data[0].membership$).toBe("a", {
-              a: bobMembership,
-            });
-            expectObservable(data[0].connection$).toBe("a", {
-              // The real connection should be from transportA as per the membership
-              a: connectionA,
-            });
-            expectObservable(data[0].participant.value$).toBe("a", {
-              // No participant as Bob is not publishing on his membership transport
-              a: null,
-            });
-            return true;
-          }),
-        },
-      );
-    });
   });
+
+  await flushPromises();
+  expect(matrixLivekitMember$.value.value).toSatisfy(
+    (data: RemoteMatrixLivekitMember[]) => {
+      expect(data.length).toEqual(2);
+      expect(data[0].membership$.value).toBe(bobMembership);
+      expect(data[0].connection$.value).toBe(connectionA);
+      expect(data[0].participant.value$.value).toBe(null);
+      return true;
+    },
+  );
 });

src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts

@@ -84,7 +84,6 @@ export function createMatrixLivekitMembers$({
   /**
    * Stream of all the call members and their associated livekit data (if available).
    */
-
   return scope.behavior(
     combineLatest([
       membershipsWithTransport$,
@@ -93,47 +92,39 @@ export function createMatrixLivekitMembers$({
       filter((values) =>
         values.every((value) => value.epoch === values[0].epoch),
       ),
-      map(
+      map(([ms, data]) => new Epoch([ms.value, data.value] as const, ms.epoch)),
-        ([
-          { value: membershipsWithTransports, epoch },
-          { value: managerData },
-        ]) =>
-          new Epoch([membershipsWithTransports, managerData] as const, epoch),
-      ),
       generateItemsWithEpoch(
         // Generator function.
         // creates an array of `{key, data}[]`
         // Each change in the keys (new key, missing key) will result in a call to the factory function.
-        function* ([membershipsWithTransports, managerData]) {
+        function* ([membershipsWithTransport, managerData]) {
-          for (const { membership, transport } of membershipsWithTransports) {
+          for (const { membership, transport } of membershipsWithTransport) {
-            // TODO! cannot use membership.membershipID yet, Currently its hardcoded by the jwt service to
-            const participantId = /*membership.membershipID*/ `${membership.userId}:${membership.deviceId}`;
-
             const participants = transport
               ? managerData.getParticipantsForTransport(transport)
               : [];
             const participant =
-              participants.find((p) => p.identity == participantId) ?? null;
+              participants.find(
+                (p) => p.identity == membership.rtcBackendIdentity,
+              ) ?? null;
             const connection = transport
               ? managerData.getConnectionForTransport(transport)
               : null;
 
             yield {
-              keys: [participantId, membership.userId],
+              keys: [membership.userId, membership.deviceId],
               data: { membership, participant, connection },
             };
           }
         },
         // Each update where the key of the generator array do not change will result in updates to the `data$` observable in the factory.
-        (scope, data$, participantId, userId) => {
+        (scope, data$, userId, deviceId) => {
           logger.debug(
-            `Generating member for participantId: ${participantId}, userId: ${userId}`,
+            `Generating member for livekitIdentity: ${data$.value.membership.rtcBackendIdentity}, userId:deviceId: ${userId}${deviceId}`,
           );
           const { participant$, ...rest } = scope.splitBehavior(data$);
           // will only get called once per `participantId, userId` pair.
           // updates to data$ and as a result to displayName$ and mxcAvatarUrl$ are more frequent.
           return {
-            participantId,
             userId,
             participant: { type: "remote" as const, value$: participant$ },
             ...rest,
@@ -141,15 +132,16 @@ export function createMatrixLivekitMembers$({
         },
       ),
     ),
+    new Epoch([], -1),
   );
 }
 
 // TODO add back in the callviewmodel pauseWhen(this.pretendToBeDisconnected$)
 
 // TODO add this to the JS-SDK
-export function areLivekitTransportsEqual(
+export function areLivekitTransportsEqual<T extends LivekitTransport>(
-  t1: LivekitTransport | null,
+  t1: T | null,
-  t2: LivekitTransport | 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)

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

@@ -18,7 +18,7 @@ import { it } from "vitest";
 import { ObservableScope } from "../../ObservableScope.ts";
 import type { Room as MatrixRoom } from "matrix-js-sdk/lib/models/room";
 import {
-  mockCallMembership,
+  mockRtcMembership,
   mockMatrixRoomMember,
   withTestScheduler,
 } from "../../../utils/test.ts";
@@ -111,7 +111,7 @@ describe("MatrixMemberMetadata", () => {
           rawDisplayName: "it's a me",
         });
         const memberships$ = behavior("a", {
-          a: [mockCallMembership("@local:example.com", "DEVICE1")],
+          a: [mockRtcMembership("@local:example.com", "DEVICE1")],
         });
         const metadataStore = createMatrixMemberMetadata$(
           testScope,
@@ -149,8 +149,8 @@ describe("MatrixMemberMetadata", () => {
       withTestScheduler(({ behavior, expectObservable }) => {
         const memberships$ = behavior("a", {
           a: [
-            mockCallMembership("@alice:example.com", "DEVICE1"),
+            mockRtcMembership("@alice:example.com", "DEVICE1"),
-            mockCallMembership("@bob:example.com", "DEVICE1"),
+            mockRtcMembership("@bob:example.com", "DEVICE1"),
           ],
         });
         const metadataStore = createMatrixMemberMetadata$(
@@ -179,7 +179,7 @@ describe("MatrixMemberMetadata", () => {
         setUpBasicRoom();
 
         const memberships$ = behavior("a", {
-          a: [mockCallMembership("@no-name:foo.bar", "D000")],
+          a: [mockRtcMembership("@no-name:foo.bar", "D000")],
         });
         const metadataStore = createMatrixMemberMetadata$(
           testScope,
@@ -201,11 +201,11 @@ describe("MatrixMemberMetadata", () => {
 
         const memberships$ = behavior("a", {
           a: [
-            mockCallMembership("@bob:example.com", "DEVICE1"),
+            mockRtcMembership("@bob:example.com", "DEVICE1"),
-            mockCallMembership("@bob:example.com", "DEVICE2"),
+            mockRtcMembership("@bob:example.com", "DEVICE2"),
-            mockCallMembership("@bob:foo.bar", "BOB000"),
+            mockRtcMembership("@bob:foo.bar", "BOB000"),
-            mockCallMembership("@carl:example.com", "C000"),
+            mockRtcMembership("@carl:example.com", "C000"),
-            mockCallMembership("@evil:example.com", "E000"),
+            mockRtcMembership("@evil:example.com", "E000"),
           ],
         });
 
@@ -233,10 +233,10 @@ describe("MatrixMemberMetadata", () => {
         setUpBasicRoom();
 
         const memberships$ = behavior("ab", {
-          a: [mockCallMembership("@bob:example.com", "DEVICE1")],
+          a: [mockRtcMembership("@bob:example.com", "DEVICE1")],
           b: [
-            mockCallMembership("@bob:example.com", "DEVICE1"),
+            mockRtcMembership("@bob:example.com", "DEVICE1"),
-            mockCallMembership("@bob:foo.bar", "BOB000"),
+            mockRtcMembership("@bob:foo.bar", "BOB000"),
           ],
         });
 
@@ -262,10 +262,10 @@ describe("MatrixMemberMetadata", () => {
 
         const memberships$ = behavior("ab", {
           a: [
-            mockCallMembership("@bob:example.com", "DEVICE1"),
+            mockRtcMembership("@bob:example.com", "DEVICE1"),
-            mockCallMembership("@bob:foo.bar", "BOB000"),
+            mockRtcMembership("@bob:foo.bar", "BOB000"),
           ],
-          b: [mockCallMembership("@bob:example.com", "DEVICE1")],
+          b: [mockRtcMembership("@bob:example.com", "DEVICE1")],
         });
 
         const metadataStore = createMatrixMemberMetadata$(
@@ -292,8 +292,8 @@ describe("MatrixMemberMetadata", () => {
 
         const memberships$ = behavior("a", {
           a: [
-            mockCallMembership("@bob:example.com", "B000"),
+            mockRtcMembership("@bob:example.com", "B000"),
-            mockCallMembership("@carl:example.com", "C000"),
+            mockRtcMembership("@carl:example.com", "C000"),
           ],
         });
         const metadataStore = createMatrixMemberMetadata$(
@@ -331,16 +331,16 @@ describe("MatrixMemberMetadata", () => {
         // - room join/leave
         // - disambiguate
         const memberships$ = behavior("ab-d", {
-          a: [mockCallMembership(CARL, "C000")],
+          a: [mockRtcMembership(CARL, "C000")],
           b: [
-            mockCallMembership(CARL, "C000"),
+            mockRtcMembership(CARL, "C000"),
             // bob joins
-            mockCallMembership(BOB, "B000"),
+            mockRtcMembership(BOB, "B000"),
           ],
           // c carl gets renamed to BOB
           d: [
             // carl leaves
-            mockCallMembership(BOB, "B000"),
+            mockRtcMembership(BOB, "B000"),
           ],
         });
         schedule("--a-", {
@@ -379,8 +379,8 @@ describe("MatrixMemberMetadata", () => {
 
     it("should disambiguate users with invisible characters", () => {
       withTestScheduler(({ behavior, expectObservable }) => {
-        const bobRtcMember = mockCallMembership("@bob:example.org", "BBBB");
+        const bobRtcMember = mockRtcMembership("@bob:example.org", "BBBB");
-        const bobZeroWidthSpaceRtcMember = mockCallMembership(
+        const bobZeroWidthSpaceRtcMember = mockRtcMembership(
           "@bob2:example.org",
           "BBBB",
         );
@@ -397,9 +397,9 @@ describe("MatrixMemberMetadata", () => {
         fakeMemberWith(bobZeroWidthSpace);
         fakeMemberWith({ userId: "@carol:example.org" });
         const memberships$ = behavior("ab", {
-          a: [mockCallMembership("@carol:example.org", "1111"), bobRtcMember],
+          a: [mockRtcMembership("@carol:example.org", "1111"), bobRtcMember],
           b: [
-            mockCallMembership("@carol:example.org", "1111"),
+            mockRtcMembership("@carol:example.org", "1111"),
             bobRtcMember,
             bobZeroWidthSpaceRtcMember,
           ],
@@ -450,8 +450,8 @@ describe("MatrixMemberMetadata", () => {
 
     it("should strip RTL characters from displayname", () => {
       withTestScheduler(({ behavior, expectObservable }) => {
-        const daveRtcMember = mockCallMembership("@dave:example.org", "DDDD");
+        const daveRtcMember = mockRtcMembership("@dave:example.org", "DDDD");
-        const daveRTLRtcMember = mockCallMembership(
+        const daveRTLRtcMember = mockRtcMembership(
           "@dave2:example.org",
           "DDDD",
         );
@@ -466,9 +466,9 @@ describe("MatrixMemberMetadata", () => {
         fakeMemberWith(daveRTL);
         fakeMemberWith(dave);
         const memberships$ = behavior("ab", {
-          a: [mockCallMembership("@carol:example.org", "DDDD")],
+          a: [mockRtcMembership("@carol:example.org", "DDDD")],
           b: [
-            mockCallMembership("@carol:example.org", "DDDD"),
+            mockRtcMembership("@carol:example.org", "DDDD"),
             daveRtcMember,
             daveRTLRtcMember,
           ],
@@ -527,8 +527,8 @@ describe("MatrixMemberMetadata", () => {
         });
         const memberships$ = behavior("a", {
           a: [
-            mockCallMembership("@local:example.com", "DEVICE1"),
+            mockRtcMembership("@local:example.com", "DEVICE1"),
-            mockCallMembership("@alice:example.com", "DEVICE1"),
+            mockRtcMembership("@alice:example.com", "DEVICE1"),
           ],
         });
         const metadataStore = createMatrixMemberMetadata$(
@@ -562,12 +562,12 @@ describe("MatrixMemberMetadata", () => {
         fakeMemberWith({ userId: "@carl:example.com" });
         fakeMemberWith({ userId: "@bob:example.com" });
         const memberships$ = behavior("ab-d", {
-          a: [mockCallMembership("@bob:example.com", "B000")],
+          a: [mockRtcMembership("@bob:example.com", "B000")],
           b: [
-            mockCallMembership("@bob:example.com", "B000"),
+            mockRtcMembership("@bob:example.com", "B000"),
-            mockCallMembership("@carl:example.com", "C000"),
+            mockRtcMembership("@carl:example.com", "C000"),
           ],
-          d: [mockCallMembership("@carl:example.com", "C000")],
+          d: [mockRtcMembership("@carl:example.com", "C000")],
         });
 
         const metadataStore = createMatrixMemberMetadata$(

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

@@ -21,8 +21,9 @@ import {
 import { ECConnectionFactory } from "./ConnectionFactory.ts";
 import { type OpenIDClientParts } from "../../../livekit/openIDSFU.ts";
 import {
-  mockCallMembership,
   mockMediaDevices,
+  mockRtcMembership,
+  ownMemberMock,
   withTestScheduler,
 } from "../../../utils/test.ts";
 import { type ProcessorState } from "../../../livekit/TrackProcessorContext.tsx";
@@ -33,6 +34,7 @@ import {
 } from "./MatrixLivekitMembers.ts";
 import { createConnectionManager$ } from "./ConnectionManager.ts";
 import { membershipsAndTransports$ } from "../../SessionBehaviors.ts";
+import { constant } from "../../Behavior.ts";
 import { testJWTToken } from "../../../utils/test-fixtures.ts";
 
 // Test the integration of ConnectionManager and MatrixLivekitMerger
@@ -99,9 +101,9 @@ afterEach(() => {
 
 test("bob, carl, then bob joining no tracks yet", () => {
   withTestScheduler(({ expectObservable, behavior, scope }) => {
-    const bobMembership = mockCallMembership("@bob:example.com", "BDEV000");
+    const bobMembership = mockRtcMembership("@bob:example.com", "BDEV000");
-    const carlMembership = mockCallMembership("@carl:example.com", "CDEV000");
+    const carlMembership = mockRtcMembership("@carl:example.com", "CDEV000");
-    const daveMembership = mockCallMembership("@dave:foo.bar", "DDEV000");
+    const daveMembership = mockRtcMembership("@dave:foo.bar", "DDEV000");
 
     const eMarble = "abc";
     const vMarble = "abc";
@@ -121,8 +123,10 @@ test("bob, carl, then bob joining no tracks yet", () => {
     const connectionManager = createConnectionManager$({
       scope: testScope,
       connectionFactory: ecConnectionFactory,
-      inputTransports$: membershipsAndTransports.transports$,
+      localTransport$: constant(null),
+      remoteTransports$: membershipsAndTransports.transports$,
       logger: logger,
+      ownMembershipIdentity: ownMemberMock,
     });
 
     const matrixLivekitMembers$ = createMatrixLivekitMembers$({

src/state/CallViewModelWidget.test.ts

@@ -37,7 +37,7 @@ vi.mock("../widget", () => ({
 
 it.each([
   [MatrixRTCMode.Legacy],
-  [MatrixRTCMode.Compatibil],
+  [MatrixRTCMode.Compatibility],
   [MatrixRTCMode.Matrix_2_0],
 ])(
   "expect leave when ElementWidgetActions.HangupCall is called (%s mode)",

src/state/MediaViewModel.ts

@@ -257,6 +257,7 @@ abstract class BaseMediaViewModel {
      * The Matrix user to which this media belongs.
      */
     public readonly userId: string,
+    public readonly rtcBackendIdentity: string,
     // We don't necessarily have a participant if a user connects via MatrixRTC but not (yet) through
     // livekit.
     protected readonly participant$: Observable<
@@ -406,6 +407,7 @@ abstract class BaseUserMediaViewModel extends BaseMediaViewModel {
     scope: ObservableScope,
     id: string,
     userId: string,
+    rtcBackendIdentity: string,
     participant$: Observable<LocalParticipant | RemoteParticipant | null>,
     encryptionSystem: EncryptionSystem,
     livekitRoom$: Behavior<LivekitRoom | undefined>,
@@ -419,6 +421,7 @@ abstract class BaseUserMediaViewModel extends BaseMediaViewModel {
       scope,
       id,
       userId,
+      rtcBackendIdentity,
       participant$,
       encryptionSystem,
       Track.Source.Microphone,
@@ -544,6 +547,7 @@ export class LocalUserMediaViewModel extends BaseUserMediaViewModel {
     scope: ObservableScope,
     id: string,
     userId: string,
+    rtcBackendIdentity: string,
     participant$: Behavior<LocalParticipant | null>,
     encryptionSystem: EncryptionSystem,
     livekitRoom$: Behavior<LivekitRoom | undefined>,
@@ -558,6 +562,7 @@ export class LocalUserMediaViewModel extends BaseUserMediaViewModel {
       scope,
       id,
       userId,
+      rtcBackendIdentity,
       participant$,
       encryptionSystem,
       livekitRoom$,
@@ -671,6 +676,7 @@ export class RemoteUserMediaViewModel extends BaseUserMediaViewModel {
     scope: ObservableScope,
     id: string,
     userId: string,
+    rtcBackendIdentity: string,
     participant$: Observable<RemoteParticipant | null>,
     encryptionSystem: EncryptionSystem,
     livekitRoom$: Behavior<LivekitRoom | undefined>,
@@ -685,6 +691,7 @@ export class RemoteUserMediaViewModel extends BaseUserMediaViewModel {
       scope,
       id,
       userId,
+      rtcBackendIdentity,
       participant$,
       encryptionSystem,
       livekitRoom$,
@@ -772,6 +779,7 @@ export class ScreenShareViewModel extends BaseMediaViewModel {
     scope: ObservableScope,
     id: string,
     userId: string,
+    rtcBackendIdentity: string,
     participant$: Observable<LocalParticipant | RemoteParticipant>,
     encryptionSystem: EncryptionSystem,
     livekitRoom$: Behavior<LivekitRoom | undefined>,
@@ -785,6 +793,7 @@ export class ScreenShareViewModel extends BaseMediaViewModel {
       scope,
       id,
       userId,
+      rtcBackendIdentity,
       participant$,
       encryptionSystem,
       Track.Source.ScreenShareAudio,

src/state/ScreenShare.ts

@@ -28,6 +28,7 @@ export class ScreenShare {
     private readonly scope: ObservableScope,
     id: string,
     userId: string,
+    rtcBackendIdentity: string,
     participant: LocalParticipant | RemoteParticipant,
     encryptionSystem: EncryptionSystem,
     livekitRoom$: Behavior<LivekitRoom | undefined>,
@@ -40,6 +41,7 @@ export class ScreenShare {
       this.scope,
       id,
       userId,
+      rtcBackendIdentity,
       of(participant),
       encryptionSystem,
       livekitRoom$,

src/state/UserMedia.ts

@@ -75,6 +75,7 @@ export class UserMedia {
           this.scope,
           this.id,
           this.userId,
+          this.rtcBackendIdentity,
           this.participant.value$,
           this.encryptionSystem,
           this.livekitRoom$,
@@ -89,6 +90,7 @@ export class UserMedia {
           this.scope,
           this.id,
           this.userId,
+          this.rtcBackendIdentity,
           this.participant.value$,
           this.encryptionSystem,
           this.livekitRoom$,
@@ -140,6 +142,7 @@ export class UserMedia {
                     scope,
                     `${this.id}:${key}`,
                     this.userId,
+                    this.rtcBackendIdentity,
                     p,
                     this.encryptionSystem,
                     this.livekitRoom$,
@@ -191,6 +194,7 @@ export class UserMedia {
     private readonly scope: ObservableScope,
     public readonly id: string,
     private readonly userId: string,
+    private readonly rtcBackendIdentity: string,
     private readonly participant: TaggedParticipant,
     private readonly encryptionSystem: EncryptionSystem,
     private readonly livekitRoom$: Behavior<LivekitRoom | undefined>,

src/tile/GridTile.tsx

@@ -113,6 +113,7 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
     },
     [vm],
   );
+  const rtcBackendIdentity = vm.rtcBackendIdentity;
   const handRaised = useBehavior(vm.handRaised$);
   const reaction = useBehavior(vm.reaction$);
 
@@ -200,6 +201,7 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
       focusUrl={focusUrl}
       audioStreamStats={audioStreamStats}
       videoStreamStats={videoStreamStats}
+      rtcBackendIdentity={rtcBackendIdentity}
       {...props}
     />
   );

src/tile/MediaView.tsx

@@ -18,7 +18,11 @@ import styles from "./MediaView.module.css";
 import { Avatar } from "../Avatar";
 import { type EncryptionStatus } from "../state/MediaViewModel";
 import { RaisedHandIndicator } from "../reactions/RaisedHandIndicator";
-import { showHandRaisedTimer, useSetting } from "../settings/settings";
+import {
+  showConnectionStats,
+  showHandRaisedTimer,
+  useSetting,
+} from "../settings/settings";
 import { type ReactionOption } from "../reactions";
 import { ReactionIndicator } from "../reactions/ReactionIndicator";
 import { RTCConnectionStats } from "../RTCConnectionStats";
@@ -46,6 +50,7 @@ interface Props extends ComponentProps<typeof animated.div> {
   waitingForMedia?: boolean;
   audioStreamStats?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
   videoStreamStats?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
+  rtcBackendIdentity?: string;
   // The focus url, mainly for debugging purposes
   focusUrl?: string;
 }
@@ -74,11 +79,13 @@ export const MediaView: FC<Props> = ({
   waitingForMedia,
   audioStreamStats,
   videoStreamStats,
+  rtcBackendIdentity,
   focusUrl,
   ...props
 }) => {
   const { t } = useTranslation();
   const [handRaiseTimerVisible] = useSetting(showHandRaisedTimer);
+  const [showConnectioStats] = useSetting(showConnectionStats);
 
   const avatarSize = Math.round(Math.min(targetWidth, targetHeight) / 2);
 
@@ -132,14 +139,18 @@ export const MediaView: FC<Props> = ({
         {waitingForMedia && (
           <div className={styles.status}>
             {t("video_tile.waiting_for_media")}
+            {showConnectioStats ? " " + rtcBackendIdentity : ""}
           </div>
         )}
         {(audioStreamStats || videoStreamStats) && (
-          <RTCConnectionStats
+          <>
-            audio={audioStreamStats}
+            <RTCConnectionStats
-            video={videoStreamStats}
+              audio={audioStreamStats}
-            focusUrl={focusUrl}
+              video={videoStreamStats}
-          />
+              focusUrl={focusUrl}
+              rtcBackendIdentity={rtcBackendIdentity}
+            />
+          </>
         )}
         {/* TODO: Bring this back once encryption status is less broken */}
         {/*encryptionStatus !== EncryptionStatus.Okay && (

src/utils/errors.ts

@@ -19,6 +19,7 @@ export enum ErrorCode {
   INSUFFICIENT_CAPACITY_ERROR = "INSUFFICIENT_CAPACITY_ERROR",
   E2EE_NOT_SUPPORTED = "E2EE_NOT_SUPPORTED",
   OPEN_ID_ERROR = "OPEN_ID_ERROR",
+  NO_MATRIX_2_AUTHORIZATION_SERVICE = "NO_MATRIX_2_0_AUTHORIZATION_SERVICE",
   SFU_ERROR = "SFU_ERROR",
   UNKNOWN_ERROR = "UNKNOWN_ERROR",
 }
@@ -171,6 +172,23 @@ export class FailToGetOpenIdToken extends ElementCallError {
   }
 }
 
+export class NoMatrix2AuthorizationService extends ElementCallError {
+  /**
+   * Creates an instance of NoMatrix2_0AuthorizationService.
+   * @param error - The underlying error that caused the failure.
+   */
+  public constructor(error: Error) {
+    super(
+      t("error.generic"),
+      ErrorCode.NO_MATRIX_2_AUTHORIZATION_SERVICE,
+      ErrorCategory.CONFIGURATION_ISSUE,
+      t("error.no_matrix_2_authorization_service"),
+      // Properly set it as a cause for a better reporting on sentry
+      error,
+    );
+  }
+}
+
 /**
  * Error indicating a failure to start publishing on a LiveKit connection.
  */

src/utils/test-fixtures.ts

@@ -17,14 +17,16 @@ export const localRtcMemberDevice2 = mockRtcMembership(
   "2222",
 );
 export const local = mockMatrixRoomMember(localRtcMember);
-// export const localParticipant = mockLocalParticipant({ identity: "" });
+
 export const localId = `${local.userId}:${localRtcMember.deviceId}`;
 
-export const aliceRtcMember = mockRtcMembership("@alice:example.org", "AAAA");
+export const aliceDeviceId = "AAAA";
+export const aliceUserId = "@alice:example.org";
+export const aliceId = `${aliceUserId}:${aliceDeviceId}`;
+export const aliceRtcMember = mockRtcMembership(aliceUserId, aliceDeviceId);
 export const alice = mockMatrixRoomMember(aliceRtcMember, {
   rawDisplayName: "Alice",
 });
-export const aliceId = `${alice.userId}:${aliceRtcMember.deviceId}`;
 export const aliceParticipant = mockRemoteParticipant({ identity: aliceId });
 
 export const aliceDoppelgangerRtcMember = mockRtcMembership(
@@ -38,11 +40,13 @@ export const aliceDoppelganger = mockMatrixRoomMember(
   },
 );
 
-export const bobRtcMember = mockRtcMembership("@bob:example.org", "BBBB");
+export const bobDeviceId = "BBBB";
+export const bobUserId = "@bob:example.org";
+export const bobId = `${bobUserId}:${bobDeviceId}`;
+export const bobRtcMember = mockRtcMembership(bobUserId, bobDeviceId);
 export const bob = mockMatrixRoomMember(bobRtcMember, {
   rawDisplayName: "Bob",
 });
-export const bobId = `${bob.userId}:${bobRtcMember.deviceId}`;
 
 export const bobZeroWidthSpaceRtcMember = mockRtcMembership(
   "@bob2:example.org",

src/utils/test.ts

@@ -50,6 +50,7 @@ import {
   type KeyTransportEvents,
   type KeyTransportEventsHandlerMap,
 } from "matrix-js-sdk/lib/matrixrtc/IKeyTransport";
+import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
 
 import {
   LocalUserMediaViewModel,
@@ -201,40 +202,30 @@ export const exampleTransport: LivekitTransport = {
   livekit_alias: "!alias:example.org",
 };
 
-export function mockCallMembership(
-  userId: string,
-  deviceId: string,
-  transport?: Transport,
-): CallMembership {
-  const t = transport ?? transportForUser(userId);
-  return {
-    userId: userId,
-    deviceId: deviceId,
-    getTransport: vi.fn().mockReturnValue(t),
-    transports: [t],
-  } as unknown as CallMembership;
-}
-
-function transportForUser(userId: string): Transport {
-  const domain = userId.split(":")[1];
-  return {
-    type: "livekit",
-    livekit_service_url: `https://lk.${domain}`,
-    livekit_alias: `!alias:${domain}`,
-  };
-}
-
 export function mockRtcMembership(
   user: string | RoomMember,
   deviceId: string,
-  callId = "",
+  customOverwrites?: {
-  fociPreferred: Transport[] = [exampleTransport],
+    rtcBackendIdentity?: string;
-  focusActive: LivekitFocusSelection = {
+    callId?: string;
-    type: "livekit",
+    fociPreferred?: Transport[];
-    focus_selection: "oldest_membership",
+    focusActive?: LivekitFocusSelection;
+    membership?: Partial<SessionMembershipData>;
   },
-  membership: Partial<SessionMembershipData> = {},
 ): CallMembership {
+  // setup defaults based on overwrites and fallback values.
+  const { rtcBackendIdentity, callId, fociPreferred, focusActive, membership } =
+    {
+      fociPreferred: [exampleTransport],
+      focusActive: {
+        type: "livekit" as const,
+        focus_selection: "oldest_membership" as const,
+      },
+      callId: "",
+      membership: {},
+      ...customOverwrites,
+    };
+
   const data: SessionMembershipData = {
     application: "m.call",
     call_id: callId,
@@ -243,17 +234,29 @@ export function mockRtcMembership(
     focus_active: focusActive,
     ...membership,
   };
+  const userId = typeof user === "string" ? user : user.userId;
   const event = new MatrixEvent({
-    sender: typeof user === "string" ? user : user.userId,
+    sender: userId,
     event_id: `$-ev-${randomUUID()}:example.org`,
     content: data,
   });
 
-  const cms = new CallMembership(event, data);
+  const membershipData = CallMembership.membershipDataFromMatrixEvent(event);
+  const cms = new CallMembership(
+    event,
+    membershipData,
+    rtcBackendIdentity ?? `${userId}:${deviceId}`,
+  );
   vi.mocked(cms).getTransport = vi.fn().mockReturnValue(fociPreferred[0]);
+
   return cms;
 }
 
+export const ownMemberMock: CallMembershipIdentityParts = {
+  userId: "@alice:example.org",
+  deviceId: "DEVICE",
+  memberId: "@alice:example.org:DEVICE",
+};
 // Maybe it'd be good to move this to matrix-js-sdk? Our testing needs are
 // rather simple, but if one util to mock a member is good enough for us, maybe
 // it's useful for matrix-js-sdk consumers in general.
@@ -331,6 +334,7 @@ export function createLocalMedia(
     testScope(),
     "local",
     member.userId,
+    rtcMember.rtcBackendIdentity,
     constant(localParticipant),
     {
       kind: E2eeType.PER_PARTICIPANT,
@@ -376,6 +380,7 @@ export function createRemoteMedia(
     testScope(),
     "remote",
     member.userId,
+    rtcMember.rtcBackendIdentity,
     constant(participant),
     {
       kind: E2eeType.PER_PARTICIPANT,
@@ -478,7 +483,7 @@ export class MockRTCSession extends TypedEventEmitter<
     if (value !== prev) this.emit(MembershipManagerEvent.ProbablyLeft, value);
   }
 
-  public async joinRoomSession(): Promise<void> {
+  public async joinRTCSession(): Promise<void> {
     return Promise.resolve();
   }
 }

yarn.lock

@@ -3300,10 +3300,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@matrix-org/matrix-sdk-crypto-wasm@npm:^16.0.0":
+"@matrix-org/matrix-sdk-crypto-wasm@npm:^17.0.0":
-  version: 16.0.0
+  version: 17.0.0
-  resolution: "@matrix-org/matrix-sdk-crypto-wasm@npm:16.0.0"
+  resolution: "@matrix-org/matrix-sdk-crypto-wasm@npm:17.0.0"
-  checksum: 10c0/13b4ede3e618da819957abff778afefcf3baf9a2faac04a36bb5a07a44fae2ea05fbfa072eb3408d48b2b7b9aaf27242ce52c594c8ce9bf1fb8b3aade2832be1
+  checksum: 10c0/fa97e3111099057e0953e7550d6556b6e7553f3badd5b25a6988d2fcc94d22288a27e63cb204771b74ff24388d770c83f2cf5aec583f05c6ecf46509b8020570
   languageName: node
   linkType: hard
 
@@ -8399,6 +8399,7 @@ __metadata:
     typescript: "npm:^5.8.3"
     typescript-eslint-language-service: "npm:^5.0.5"
     unique-names-generator: "npm:^4.6.0"
+    uuid: "npm:^13.0.0"
     vaul: "npm:^1.0.0"
     vite: "npm:^7.0.0"
     vite-plugin-generate-file: "npm:^0.3.0"
@@ -11467,10 +11468,10 @@ __metadata:
 
 "matrix-js-sdk@matrix-org/matrix-js-sdk#develop":
   version: 39.4.0
-  resolution: "matrix-js-sdk@https://github.com/matrix-org/matrix-js-sdk.git#commit=174439c2f0c09cf9926c28435ba4db1345df4aee"
+  resolution: "matrix-js-sdk@https://github.com/matrix-org/matrix-js-sdk.git#commit=4d0d32307eb4f1ce1fb65080fcca704f5bdedc31"
   dependencies:
     "@babel/runtime": "npm:^7.12.5"
-    "@matrix-org/matrix-sdk-crypto-wasm": "npm:^16.0.0"
+    "@matrix-org/matrix-sdk-crypto-wasm": "npm:^17.0.0"
     another-json: "npm:^0.2.0"
     bs58: "npm:^6.0.0"
     content-type: "npm:^1.0.4"
@@ -11483,7 +11484,7 @@ __metadata:
     sdp-transform: "npm:^3.0.0"
     unhomoglyph: "npm:^1.0.6"
     uuid: "npm:13"
-  checksum: 10c0/5178de27bb618aed6f80632a72c5582542ceedb51ef15534493360a624b072e0c276693ad9e37d83f2ddb06716f9eb6d02960e158e029f7a005676873778c745
+  checksum: 10c0/59c9d81ccf823584dc783502cb5c928562e3490c63f5ce98ee3232a603545d6278e90dc951c1fd0bae2792ba732ec5171e03596fd396bb2150d596cebb7fbac9
   languageName: node
   linkType: hard
 
@@ -15346,7 +15347,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"uuid@npm:13":
+"uuid@npm:13, uuid@npm:^13.0.0":
   version: 13.0.0
   resolution: "uuid@npm:13.0.0"
   bin: