Merge pull request #3718 from element-hq/toger5/backport-fix_remove_livekit_alias_signaling

[backport] The advertised livekit_alias in membership is deprecated #3706
2026-03-13 06:07:04 +00:00 · 2026-02-04 14:16:51 +01:00
parent 330ad3448d c0540c105d
commit fb5098a1ed
15 changed files with 167 additions and 156 deletions
--- a/src/livekit/openIDSFU.ts
+++ b/src/livekit/openIDSFU.ts
@@ -78,8 +78,8 @@ export type OpenIDClientParts = Pick<
 * @param membership Our own membership identity parts used to send to jwt service.
 * @param serviceUrl The URL of the livekit SFU service
 * @param roomId The room id used in the jwt request. This is NOT the livekit_alias. The jwt service will provide the alias. It maps matrix room ids <-> Livekit aliases.
- * @param opts Additional options to modify which endpoint with which data will be used to aquire the jwt token.
- * @param opts.forceJwtEndpoint This will use the old jwt endpoint which will create the rtc backend identity based on string concatination
+ * @param opts Additional options to modify which endpoint with which data will be used to acquire the jwt token.
+ * @param opts.forceJwtEndpoint This will use the old jwt endpoint which will create the rtc backend identity based on string concatenation
 * instead of a hash.
 * This function by default uses whatever is possible with the current jwt service installed next to the SFU.
 * For remote connections this does not matter, since we will not publish there we can rely on the newest option.
--- a/src/state/CallViewModel/CallViewModel.ts
+++ b/src/state/CallViewModel/CallViewModel.ts
@@ -42,7 +42,7 @@ import {
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
 import {
  MembershipManagerEvent,
-  type LivekitTransport,
+  type LivekitTransportConfig,
  type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { type IWidgetApiRequest } from "matrix-widget-api";
@@ -103,7 +103,7 @@ import {
  type SpotlightPortraitLayoutMedia,
 } from "../layout-types.ts";
 import { ElementCallError, UnknownCallError } from "../../utils/errors.ts";
-import { type ObservableScope } from "../ObservableScope.ts";
+import { type Epoch, type ObservableScope } from "../ObservableScope.ts";
 import { createHomeserverConnected$ } from "./localMember/HomeserverConnected.ts";
 import {
  createLocalMembership$,
@@ -468,6 +468,7 @@ export function createCallViewModel$(

  const connectionFactory = new ECConnectionFactory(
    client,
+    matrixRoom.roomId,
    mediaDevices,
    trackProcessorState$,
    livekitKeyProvider,
@@ -496,12 +497,13 @@ export function createCallViewModel$(
    ownMembershipIdentity,
  });

-  const matrixLivekitMembers$ = createMatrixLivekitMembers$({
-    scope: scope,
-    membershipsWithTransport$:
-      membershipsAndTransports.membershipsWithTransport$,
-    connectionManager: connectionManager,
-  });
+  const matrixLivekitMembers$: Behavior<Epoch<RemoteMatrixLivekitMember[]>> =
+    createMatrixLivekitMembers$({
+      scope: scope,
+      membershipsWithTransport$:
+        membershipsAndTransports.membershipsWithTransport$,
+      connectionManager: connectionManager,
+    });

  const connectOptions$ = scope.behavior(
    matrixRTCMode$.pipe(
@@ -521,7 +523,7 @@ export function createCallViewModel$(
      matrixRTCSession,
    ),
    muteStates: muteStates,
-    joinMatrixRTC: (transport: LivekitTransport) => {
+    joinMatrixRTC: (transport: LivekitTransportConfig) => {
      return enterRTCSession(
        matrixRTCSession,
        ownMembershipIdentity,
--- a/src/state/CallViewModel/localMember/LocalMember.test.ts
+++ b/src/state/CallViewModel/localMember/LocalMember.test.ts
@@ -8,7 +8,7 @@ Please see LICENSE in the repository root for full details.

 import {
  Status as RTCMemberStatus,
-  type LivekitTransport,
+  type LivekitTransportConfig,
  type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { describe, expect, it, vi } from "vitest";
@@ -281,7 +281,7 @@ describe("LocalMembership", () => {
  const aTransport = {
    transport: {
      livekit_service_url: "a",
-    } as LivekitTransport,
+    } as LivekitTransportConfig,
    sfuConfig: {
      url: "sfu-url",
      jwt: "sfu-token",
@@ -290,7 +290,7 @@ describe("LocalMembership", () => {
  const bTransport = {
    transport: {
      livekit_service_url: "b",
-    } as LivekitTransport,
+    } as LivekitTransportConfig,
    sfuConfig: {
      url: "sfu-url",
      jwt: "sfu-token",
--- a/src/state/CallViewModel/localMember/LocalMember.ts
+++ b/src/state/CallViewModel/localMember/LocalMember.ts
@@ -17,6 +17,7 @@ import { observeParticipantEvents } from "@livekit/components-core";
 import {
  Status as RTCSessionStatus,
  type LivekitTransport,
+  type LivekitTransportConfig,
  type MatrixRTCSession,
 } from "matrix-js-sdk/lib/matrixrtc";
 import {
@@ -125,7 +126,7 @@ interface Props {
  muteStates: MuteStates;
  connectionManager: IConnectionManager;
  createPublisherFactory: (connection: Connection) => Publisher;
-  joinMatrixRTC: (transport: LivekitTransport) => void;
+  joinMatrixRTC: (transport: LivekitTransportConfig) => void;
  homeserverConnected: HomeserverConnected;
  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
  matrixRTCSession: Pick<
@@ -717,7 +718,7 @@ interface EnterRTCSessionOptions {
 export function enterRTCSession(
  rtcSession: MatrixRTCSession,
  ownMembershipIdentity: CallMembershipIdentityParts,
-  transport: LivekitTransport,
+  transport: LivekitTransportConfig,
  options: EnterRTCSessionOptions,
 ): void {
  const { encryptMedia, matrixRTCMode } = options;
@@ -735,12 +736,26 @@ export function enterRTCSession(
  const multiSFU =
    matrixRTCMode === MatrixRTCMode.Compatibility ||
    matrixRTCMode === MatrixRTCMode.Matrix_2_0;
+
+  // For backwards compatibility with Element Call versions that do not do Matrix 2.0,
+  // we add the livekit alias to the transport.
+  let backwardCompatibleTransport: LivekitTransport | LivekitTransportConfig;
+  if (matrixRTCMode === MatrixRTCMode.Matrix_2_0) {
+    backwardCompatibleTransport = transport;
+  } else {
+    backwardCompatibleTransport = {
+      livekit_alias: rtcSession.room.roomId,
+      ...transport,
+    };
+  }
+
  // Multi-sfu does not need a preferred foci list. just the focus that is actually used.
  // TODO where/how do we track errors originating from the ongoing rtcSession?
+
  rtcSession.joinRTCSession(
    ownMembershipIdentity,
-    multiSFU ? [] : [transport],
-    multiSFU ? transport : undefined,
+    multiSFU ? [] : [backwardCompatibleTransport],
+    multiSFU ? backwardCompatibleTransport : undefined,
    {
      notificationType,
      callIntent,
--- a/src/state/CallViewModel/localMember/LocalTransport.test.ts
+++ b/src/state/CallViewModel/localMember/LocalTransport.test.ts
@@ -34,7 +34,7 @@ describe("LocalTransport", () => {
  const openIdResponse: openIDSFU.SFUConfig = {
    url: "https://lk.example.org",
    jwt: testJWTToken,
-    livekitAlias: "!example_room_id",
+    livekitAlias: "Akph4alDMhen",
    livekitIdentity: "@lk_user:ABCDEF",
  };

@@ -147,7 +147,7 @@ describe("LocalTransport", () => {
    openIdResolver.resolve?.({
      url: "https://lk.example.org",
      jwt: "jwt",
-      livekitAlias: "!room:example.org",
+      livekitAlias: "Akph4alDMhen",
      livekitIdentity: ownMemberMock.userId + ":" + ownMemberMock.deviceId,
    });
    expect(localTransport$.value).toBe(null);
@@ -155,13 +155,12 @@ describe("LocalTransport", () => {
    // final
    expect(localTransport$.value).toStrictEqual({
      transport: {
-        livekit_alias: "!room:example.org",
        livekit_service_url: "https://lk.example.org",
        type: "livekit",
      },
      sfuConfig: {
        jwt: "jwt",
-        livekitAlias: "!room:example.org",
+        livekitAlias: "Akph4alDMhen",
        livekitIdentity: "@alice:example.org:DEVICE",
        url: "https://lk.example.org",
      },
@@ -204,13 +203,12 @@ describe("LocalTransport", () => {
    // final
    expect(localTransport$.value).toStrictEqual({
      transport: {
-        livekit_alias: "!example_room_id",
        livekit_service_url: "https://lk.example.org",
        type: "livekit",
      },
      sfuConfig: {
        jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-        livekitAlias: "!example_room_id",
+        livekitAlias: "Akph4alDMhen",
        livekitIdentity: "@lk_user:ABCDEF",
        url: "https://lk.example.org",
      },
@@ -264,13 +262,12 @@ describe("LocalTransport", () => {
      await flushPromises();
      expect(localTransport$.value).toStrictEqual({
        transport: {
-          livekit_alias: "!example_room_id",
          livekit_service_url: "https://lk.example.org",
          type: "livekit",
        },
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
          livekitIdentity: "@lk_user:ABCDEF",
          url: "https://lk.example.org",
        },
@@ -284,13 +281,12 @@ describe("LocalTransport", () => {
      await flushPromises();
      expect(localTransport$.value).toStrictEqual({
        transport: {
-          livekit_alias: "!example_room_id",
          livekit_service_url: "https://lk.example.org",
          type: "livekit",
        },
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
          livekitIdentity: "@lk_user:ABCDEF",
          url: "https://lk.example.org",
        },
@@ -306,13 +302,12 @@ describe("LocalTransport", () => {
      await flushPromises();
      expect(localTransport$.value).toStrictEqual({
        transport: {
-          livekit_alias: "!example_room_id",
          livekit_service_url: "https://lk.example.org",
          type: "livekit",
        },
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
          livekitIdentity: "@lk_user:ABCDEF",
          url: "https://lk.example.org",
        },
@@ -345,13 +340,12 @@ describe("LocalTransport", () => {
      await flushPromises();
      expect(localTransport$.value).toStrictEqual({
        transport: {
-          livekit_alias: "!example_room_id",
          livekit_service_url: "https://lk.example.org",
          type: "livekit",
        },
        sfuConfig: {
          jwt: "e30=.eyJzdWIiOiJAbWU6ZXhhbXBsZS5vcmc6QUJDREVGIiwidmlkZW8iOnsicm9vbSI6IiFleGFtcGxlX3Jvb21faWQifX0=.e30=",
-          livekitAlias: "!example_room_id",
+          livekitAlias: "Akph4alDMhen",
          livekitIdentity: "@lk_user:ABCDEF",
          url: "https://lk.example.org",
        },
--- a/src/state/CallViewModel/localMember/LocalTransport.ts
+++ b/src/state/CallViewModel/localMember/LocalTransport.ts
@@ -7,10 +7,9 @@ Please see LICENSE in the repository root for full details.

 import {
  type CallMembership,
-  isLivekitTransport,
-  type LivekitTransport,
  isLivekitTransportConfig,
  type Transport,
+  type LivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { MatrixError, type MatrixClient } from "matrix-js-sdk";
 import {
@@ -57,6 +56,7 @@ interface Props {
    "getDomain" | "baseUrl" | "_unstable_getRTCTransports"
  > &
    OpenIDClientParts;
+  // Used by the jwt service to create the livekit room and compute the livekit alias.
  roomId: string;
  useOldestMember$: Behavior<boolean>;
  forceJwtEndpoint$: Behavior<JwtEndpointVersion>;
@@ -90,11 +90,11 @@ export enum JwtEndpointVersion {
 // 2.
 // We need to make sure we do not sent livekit_alias in sticky events and that we drop all code for sending state events!
 export interface LocalTransportWithSFUConfig {
-  transport: LivekitTransport;
+  transport: LivekitTransportConfig;
  sfuConfig: SFUConfig;
 }
 export function isLocalTransportWithSFUConfig(
-  obj: LivekitTransport | LocalTransportWithSFUConfig,
+  obj: LivekitTransportConfig | LocalTransportWithSFUConfig,
 ): obj is LocalTransportWithSFUConfig {
  return "transport" in obj && "sfuConfig" in obj;
 }
@@ -137,11 +137,10 @@ export const createLocalTransport$ = ({
          return transport;
        }),
        switchMap((transport) => {
-          if (transport !== null && isLivekitTransport(transport)) {
+          if (transport !== null && isLivekitTransportConfig(transport)) {
            // Get the open jwt token to connect to the sfu
            const computeLocalTransportWithSFUConfig =
              async (): Promise<LocalTransportWithSFUConfig> => {
-                // await sleep(1000);
                return {
                  transport,
                  sfuConfig: await getSFUConfigWithOpenID(
@@ -288,18 +287,6 @@ async function makeTransport(
      transport: {
        type: "livekit",
        livekit_service_url: url,
-        // WARNING PLS READ ME!!!
-        // This looks unintuitive especially considering that `sfuConfig.livekitAlias` exists.
-        // Why do we not use: `livekit_alias: sfuConfig.livekitAlias`
-        //
-        //  - This is going to be used for sending our state event transport (focus_preferred)
-        //  - In sticky events it is expected to NOT send this field at all. The transport is only the `type`, `livekit_service_url`
-        //  - If we set it to the hased alias we get from the jwt, we will end up using the hashed alias as the body.roomId field
-        //    in v0.16.0. (It will use oldest member transport. It is using the transport.livekit_alias as the body.roomId)
-        //
-        // TLDR this is a temporal field that allow for comaptibilty but the spec expects it to not exists. (but its existance also does not break anything)
-        // It is just named poorly: It was intetended to be the actual alias. But now we do pseudonymys ids so we use a hashed alias.
-        livekit_alias: roomId,
      },
      sfuConfig,
    };
--- a/src/state/CallViewModel/remoteMembers/Connection.test.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.test.ts
@@ -26,7 +26,7 @@ import fetchMock from "fetch-mock";
 import EventEmitter from "events";
 import { type IOpenIDToken } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc/LivekitTransport";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";

 import {
  Connection,
@@ -51,8 +51,9 @@ let fakeLivekitRoom: MockedObject<LivekitRoom>;
 let localParticipantEventEmiter: EventEmitter;
 let fakeLocalParticipant: MockedObject<LocalParticipant>;

-const livekitFocus: LivekitTransport = {
-  livekit_alias: "!roomID:example.org",
+const ROOM_ID = "!roomID:example.org";
+
+const livekitFocus: LivekitTransportConfig = {
  livekit_service_url: "https://matrix-rtc.example.org/livekit/jwt",
  type: "livekit",
 };
@@ -112,6 +113,7 @@ function setupTest(): void {
 function setupRemoteConnection(): Connection {
  const opts: ConnectionOpts = {
    client: client,
+    roomId: ROOM_ID,
    transport: livekitFocus,
    scope: testScope,
    ownMembershipIdentity: ownMemberMock,
@@ -154,6 +156,7 @@ describe("Start connection states", () => {

    const opts: ConnectionOpts = {
      client: client,
+      roomId: ROOM_ID,
      transport: livekitFocus,
      scope: testScope,
      ownMembershipIdentity: ownMemberMock,
@@ -170,6 +173,7 @@ describe("Start connection states", () => {

    const opts: ConnectionOpts = {
      client: client,
+      roomId: ROOM_ID,
      transport: livekitFocus,
      scope: testScope,
      ownMembershipIdentity: ownMemberMock,
@@ -221,6 +225,7 @@ describe("Start connection states", () => {

    const opts: ConnectionOpts = {
      client: client,
+      roomId: ROOM_ID,
      transport: livekitFocus,
      scope: testScope,
      ownMembershipIdentity: ownMemberMock,
@@ -279,6 +284,7 @@ describe("Start connection states", () => {

    const opts: ConnectionOpts = {
      client: client,
+      roomId: ROOM_ID,
      transport: livekitFocus,
      scope: testScope,
      ownMembershipIdentity: ownMemberMock,
--- a/src/state/CallViewModel/remoteMembers/Connection.ts
+++ b/src/state/CallViewModel/remoteMembers/Connection.ts
@@ -15,7 +15,7 @@ import {
  type Room as LivekitRoom,
  type RemoteParticipant,
 } from "livekit-client";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { BehaviorSubject, map } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
@@ -49,9 +49,11 @@ export interface ConnectionOpts {
  /** The identity parts to use on this connection */
  ownMembershipIdentity: CallMembershipIdentityParts;
  /** The media transport to connect to. */
-  transport: LivekitTransport;
+  transport: LivekitTransportConfig;
  /** The Matrix client to use for OpenID and SFU config requests. */
  client: OpenIDClientParts;
+  /** The room ID this connection is associated with. */
+  roomId: string;
  /** The observable scope to use for this connection. */
  scope: ObservableScope;

@@ -102,7 +104,7 @@ export class Connection {
  /**
   * The media transport to connect to.
   */
-  public readonly transport: LivekitTransport;
+  public readonly transport: LivekitTransportConfig;

  public readonly livekitRoom: LivekitRoom;

@@ -131,6 +133,47 @@ export class Connection {
   * */
  protected stopped = false;

+  // TODO: can we just keep the ConnectionOpts object instead of spreading?
+  private readonly client: OpenIDClientParts;
+  private readonly roomId: string;
+  private readonly logger: Logger;
+  private readonly ownMembershipIdentity: CallMembershipIdentityParts;
+  private readonly existingSFUConfig?: SFUConfig;
+  /**
+   * Creates a new connection to a matrix RTC LiveKit backend.
+   *
+   * @param opts - Connection options {@link ConnectionOpts}.
+   *
+   * @param logger - The logger to use.
+   */
+  public constructor(opts: ConnectionOpts, logger: Logger) {
+    this.ownMembershipIdentity = opts.ownMembershipIdentity;
+    this.existingSFUConfig = opts.existingSFUConfig;
+    this.roomId = opts.roomId;
+    this.logger = logger.getChild(
+      "[Connection " + opts.transport.livekit_service_url + "]",
+    );
+    this.logger.info(
+      `constructor: ${opts.transport.livekit_service_url} roomId: ${this.roomId} withSfuConfig?: ${opts.existingSFUConfig ? JSON.stringify(opts.existingSFUConfig) : "undefined"}`,
+    );
+    const { transport, client, scope } = opts;
+
+    this.scope = scope;
+    this.livekitRoom = opts.livekitRoomFactory();
+    this.transport = transport;
+    this.client = client;
+
+    this.remoteParticipants$ = scope.behavior(
+      // Only tracks remote participants
+      connectedParticipantsObserver(this.livekitRoom),
+    );
+
+    scope.onEnd(() => {
+      this.logger.info(`Connection scope ended, stopping connection`);
+      void this.stop();
+    });
+  }
+
  /**
   * Starts the connection.
   *
@@ -231,7 +274,7 @@ export class Connection {
      this.client,
      this.ownMembershipIdentity,
      this.transport.livekit_service_url,
-      this.transport.livekit_alias,
+      this.roomId,
      // dont pass any custom opts for the subscribe only connections
      {},
      this.logger,
@@ -256,42 +299,4 @@ export class Connection {
      `stop: DONE disconnecing from lk room ${this.transport.livekit_service_url}`,
    );
  }
-
-  private readonly client: OpenIDClientParts;
-  private readonly logger: Logger;
-  private readonly ownMembershipIdentity: CallMembershipIdentityParts;
-  private readonly existingSFUConfig?: SFUConfig;
-  /**
-   * Creates a new connection to a matrix RTC LiveKit backend.
-   *
-   * @param opts - Connection options {@link ConnectionOpts}.
-   *
-   * @param logger - The logger to use.
-   */
-  public constructor(opts: ConnectionOpts, logger: Logger) {
-    this.ownMembershipIdentity = opts.ownMembershipIdentity;
-    this.existingSFUConfig = opts.existingSFUConfig;
-    this.logger = logger.getChild(
-      "[Connection " + opts.transport.livekit_service_url + "]",
-    );
-    this.logger.info(
-      `constructor: ${opts.transport.livekit_service_url} alias: ${opts.transport.livekit_alias} withSfuConfig?: ${opts.existingSFUConfig ? JSON.stringify(opts.existingSFUConfig) : "undefined"}`,
-    );
-    const { transport, client, scope } = opts;
-
-    this.scope = scope;
-    this.livekitRoom = opts.livekitRoomFactory();
-    this.transport = transport;
-    this.client = client;
-
-    this.remoteParticipants$ = scope.behavior(
-      // Only tracks remote participants
-      connectedParticipantsObserver(this.livekitRoom),
-    );
-
-    scope.onEnd(() => {
-      this.logger.info(`Connection scope ended, stopping connection`);
-      void this.stop();
-    });
-  }
 }
--- a/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionFactory.ts
@@ -16,7 +16,7 @@ import { type Logger } from "matrix-js-sdk/lib/logger";
 // imported as inline to support worker when loaded from a cdn (cross domain)
 import E2EEWorker from "livekit-client/e2ee-worker?worker&inline";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc/LivekitTransport";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";

 import { type ObservableScope } from "../../ObservableScope.ts";
 import { Connection } from "./Connection.ts";
@@ -33,7 +33,7 @@ import { defaultLiveKitOptions } from "../../../livekit/options.ts";
 export interface ConnectionFactory {
  createConnection(
    scope: ObservableScope,
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
    ownMembershipIdentity: CallMembershipIdentityParts,
    logger: Logger,
    sfuConfig?: SFUConfig,
@@ -47,6 +47,7 @@ export class ECConnectionFactory implements ConnectionFactory {
   * Creates a ConnectionFactory for LiveKit connections.
   *
   * @param client - The OpenID client parts for authentication, needed to get openID and JWT tokens.
+   * @param roomId - The current room ID.
   * @param devices - Used for video/audio out/in capture options.
   * @param processorState$ - Effects like background blur (only for publishing connection?)
   * @param livekitKeyProvider - Optional key provider for end-to-end encryption.
@@ -57,6 +58,7 @@ export class ECConnectionFactory implements ConnectionFactory {
   */
  public constructor(
    private client: OpenIDClientParts,
+    private readonly roomId: string,
    private devices: MediaDevices,
    private processorState$: Behavior<ProcessorState>,
    livekitKeyProvider: BaseKeyProvider | undefined,
@@ -95,7 +97,7 @@ export class ECConnectionFactory implements ConnectionFactory {
   */
  public createConnection(
    scope: ObservableScope,
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
    ownMembershipIdentity: CallMembershipIdentityParts,
    logger: Logger,
    sfuConfig?: SFUConfig,
@@ -103,6 +105,7 @@ export class ECConnectionFactory implements ConnectionFactory {
    return new Connection(
      {
        existingSFUConfig: sfuConfig,
+        roomId: this.roomId,
        transport,
        client: this.client,
        scope: scope,
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.test.ts
@@ -7,7 +7,7 @@ Please see LICENSE in the repository root for full details.

 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
 import { BehaviorSubject } from "rxjs";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { type RemoteParticipant } from "livekit-client";
 import { logger } from "matrix-js-sdk/lib/logger";

@@ -24,16 +24,14 @@ import { constant, type Behavior } from "../../Behavior.ts";

 // Some test constants

-const TRANSPORT_1: LivekitTransport = {
+const TRANSPORT_1: LivekitTransportConfig = {
  type: "livekit",
  livekit_service_url: "https://lk.example.org",
-  livekit_alias: "!alias:example.org",
 };

-const TRANSPORT_2: LivekitTransport = {
+const TRANSPORT_2: LivekitTransportConfig = {
  type: "livekit",
  livekit_service_url: "https://lk.sample.com",
-  livekit_alias: "!alias:sample.com",
 };

 let fakeConnectionFactory: ConnectionFactory;
@@ -49,7 +47,7 @@ beforeEach(() => {
  vi.mocked(fakeConnectionFactory).createConnection = vi
    .fn()
    .mockImplementation(
-      (scope: ObservableScope, transport: LivekitTransport) => {
+      (scope: ObservableScope, transport: LivekitTransportConfig) => {
        const mockConnection = {
          transport,
          remoteParticipants$: new BehaviorSubject([]),
@@ -209,15 +207,15 @@ describe("connectionManagerData$ stream", () => {
  // Used in test to control fake connections' remoteParticipants$ streams
  let fakeRemoteParticipantsStreams: Map<string, Behavior<RemoteParticipant[]>>;

-  function keyForTransport(transport: LivekitTransport): string {
-    return `${transport.livekit_service_url}|${transport.livekit_alias}`;
+  function keyForTransport(transport: LivekitTransportConfig): string {
+    return `${transport.livekit_service_url}`;
  }

  beforeEach(() => {
    fakeRemoteParticipantsStreams = new Map();

    function getRemoteParticipantsFor(
-      transport: LivekitTransport,
+      transport: LivekitTransportConfig,
    ): Behavior<RemoteParticipant[]> {
      return (
        fakeRemoteParticipantsStreams.get(keyForTransport(transport)) ??
@@ -229,7 +227,7 @@ describe("connectionManagerData$ stream", () => {
    vi.mocked(fakeConnectionFactory).createConnection = vi
      .fn()
      .mockImplementation(
-        (scope: ObservableScope, transport: LivekitTransport) => {
+        (scope: ObservableScope, transport: LivekitTransportConfig) => {
          const fakeRemoteParticipants$ = new BehaviorSubject<
            RemoteParticipant[]
          >([]);
--- a/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
+++ b/src/state/CallViewModel/remoteMembers/ConnectionManager.ts
@@ -6,7 +6,7 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */

-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, map, of, switchMap } from "rxjs";
 import { type Logger } from "matrix-js-sdk/lib/logger";
 import { type RemoteParticipant } from "livekit-client";
@@ -42,8 +42,10 @@ export class ConnectionManagerData {
    }
  }

-  private getKey(transport: LivekitTransport): string {
-    return transport.livekit_service_url + "|" + transport.livekit_alias;
+  private getKey(transport: LivekitTransportConfig): string {
+    // This is enough as a key because the ConnectionManager is already scoped by room.
+    // We also do not need to consider the slotId at this point since each `MatrixRTCSession` is already scoped by `slotDescription: {id, application}`.
+    return transport.livekit_service_url;
  }

  public getConnections(): Connection[] {
@@ -51,15 +53,15 @@ export class ConnectionManagerData {
  }

  public getConnectionForTransport(
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
  ): Connection | null {
    return this.store.get(this.getKey(transport))?.connection ?? null;
  }

  public getParticipantsForTransport(
-    transport: LivekitTransport,
+    transport: LivekitTransportConfig,
  ): RemoteParticipant[] {
-    const key = transport.livekit_service_url + "|" + transport.livekit_alias;
+    const key = this.getKey(transport);
    const existing = this.store.get(key);
    if (existing) {
      return existing.participants;
@@ -72,7 +74,7 @@ interface Props {
  scope: ObservableScope;
  connectionFactory: ConnectionFactory;
  localTransport$: Behavior<LocalTransportWithSFUConfig | null>;
-  remoteTransports$: Behavior<Epoch<LivekitTransport[]>>;
+  remoteTransports$: Behavior<Epoch<LivekitTransportConfig[]>>;

  logger: Logger;
  ownMembershipIdentity: CallMembershipIdentityParts;
@@ -123,7 +125,7 @@ export function createConnectionManager$({
   * externally this is modified via `registerTransports()`.
   */
  const localAndRemoteTransports$: Behavior<
-    Epoch<(LivekitTransport | LocalTransportWithSFUConfig)[]>
+    Epoch<(LivekitTransportConfig | LocalTransportWithSFUConfig)[]>
  > = scope.behavior(
    combineLatest([remoteTransports$, localTransport$]).pipe(
      // Combine local and remote transports into one transport array
@@ -168,19 +170,13 @@ export function createConnectionManager$({
              // This is the local transport only the `LocalTransportWithSFUConfig` has a `sfuConfig` field
              const { transport, sfuConfig } = transportWithOrWithoutSfuConfig;
              yield {
-                keys: [
-                  transport.livekit_service_url,
-                  transport.livekit_alias,
-                  sfuConfig,
-                ],
+                keys: [transport.livekit_service_url, sfuConfig],
                data: undefined,
              };
            } else {
-              const transport = transportWithOrWithoutSfuConfig;
              yield {
                keys: [
-                  transport.livekit_service_url,
-                  transport.livekit_alias,
+                  transportWithOrWithoutSfuConfig.livekit_service_url,
                  undefined as undefined | SFUConfig,
                ],
                data: undefined,
@@ -188,13 +184,12 @@ export function createConnectionManager$({
            }
          }
        },
-        (scope, _data$, serviceUrl, alias, sfuConfig) => {
+        (scope, _data$, serviceUrl, sfuConfig) => {
          const connection = connectionFactory.createConnection(
            scope,
            {
              type: "livekit",
              livekit_service_url: serviceUrl,
-              livekit_alias: alias,
            },
            ownMembershipIdentity,
            logger,
@@ -254,7 +249,7 @@ export function createConnectionManager$({
  return { connectionManagerData$ };
 }

-function removeDuplicateTransports<T extends LivekitTransport>(
+function removeDuplicateTransports<T extends LivekitTransportConfig>(
  transports: T[],
 ): T[] {
  return transports.reduce((acc, transport) => {
--- a/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts
+++ b/src/state/CallViewModel/remoteMembers/ECConnectionFactory.test.ts
@@ -65,6 +65,7 @@ describe("ECConnectionFactory - Audio inputs options", () => {

      const ecConnectionFactory = new ECConnectionFactory(
        mockClient,
+        "!roomid:example.org",
        mockMediaDevices({}),
        new BehaviorSubject<ProcessorState>({
          supported: true,
@@ -105,6 +106,7 @@ describe("ECConnectionFactory - ControlledAudioDevice", () => {

      const ecConnectionFactory = new ECConnectionFactory(
        mockClient,
+        "!roomid:example.org",
        mockMediaDevices({
          audioOutput: {
            available$: constant(new Map<never, never>()),
--- a/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
+++ b/src/state/CallViewModel/remoteMembers/MatrixLivekitMembers.ts
@@ -7,8 +7,8 @@ Please see LICENSE in the repository root for full details.

 import { type LocalParticipant, type RemoteParticipant } from "livekit-client";
 import {
-  type LivekitTransport,
  type CallMembership,
+  type LivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { combineLatest, filter, map } from "rxjs";
 import { logger as rootLogger } from "matrix-js-sdk/lib/logger";
@@ -62,7 +62,7 @@ export interface RemoteMatrixLivekitMember extends MatrixLivekitMember {
 interface Props {
  scope: ObservableScope;
  membershipsWithTransport$: Behavior<
-    Epoch<{ membership: CallMembership; transport?: LivekitTransport }[]>
+    Epoch<{ membership: CallMembership; transport?: LivekitTransportConfig }[]>
  >;
  connectionManager: IConnectionManager;
 }
@@ -147,18 +147,12 @@ export function createMatrixLivekitMembers$({
 // TODO add back in the callviewmodel pauseWhen(this.pretendToBeDisconnected$)

 // TODO add this to the JS-SDK
-export function areLivekitTransportsEqual<T extends LivekitTransport>(
+export function areLivekitTransportsEqual<T extends LivekitTransportConfig>(
  t1: T | null,
  t2: T | null,
 ): boolean {
-  if (t1 && t2)
-    return (
-      t1.livekit_service_url === t2.livekit_service_url &&
-      // In case we have different lk rooms in the same SFU (depends on the livekit authorization service)
-      // It is only needed in case the livekit authorization service is not behaving as expected (or custom implementation)
-      // Also LivekitTransport is planned to become a `ConnectionIdentifier` which moves this equal somewhere else.
-      t1.livekit_alias === t2.livekit_alias
-    );
-  if (!t1 && !t2) return true;
-  return false;
+  if (t1 && t2) {
+    return t1.livekit_service_url === t2.livekit_service_url;
+  }
+  return !t1 && !t2;
 }
--- a/src/state/CallViewModel/remoteMembers/integration.test.ts
+++ b/src/state/CallViewModel/remoteMembers/integration.test.ts
@@ -10,7 +10,7 @@ import { BehaviorSubject } from "rxjs";
 import { type Room as LivekitRoom } from "livekit-client";
 import EventEmitter from "events";
 import fetchMock from "fetch-mock";
-import { type LivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
+import { type LivekitTransportConfig } from "matrix-js-sdk/lib/matrixrtc";
 import { logger } from "matrix-js-sdk/lib/logger";

 import {
@@ -71,6 +71,7 @@ beforeEach(() => {

  ecConnectionFactory = new ECConnectionFactory(
    mockClient,
+    "!roomid:example.org",
    mockMediaDevices({}),
    new BehaviorSubject<ProcessorState>({
      supported: true,
@@ -148,7 +149,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
          a: expect.toSatisfy((co) =>
            areLivekitTransportsEqual(
              co.transport,
-              bobMembership.transports[0]! as LivekitTransport,
+              bobMembership.transports[0]! as LivekitTransportConfig,
            ),
          ),
        });
@@ -185,7 +186,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
              expect(
                areLivekitTransportsEqual(
                  connection.transport,
-                  carlMembership.transports[0]! as LivekitTransport,
+                  carlMembership.transports[0]! as LivekitTransportConfig,
                ),
              ).toBe(true);
              return true;
@@ -215,7 +216,7 @@ test("bob, carl, then bob joining no tracks yet", () => {
              expect(
                areLivekitTransportsEqual(
                  connection.transport,
-                  daveMembership.transports[0]! as LivekitTransport,
+                  daveMembership.transports[0]! as LivekitTransportConfig,
                ),
              ).toBe(true);
              return true;
--- a/src/state/SessionBehaviors.ts
+++ b/src/state/SessionBehaviors.ts
@@ -7,10 +7,10 @@ Please see LICENSE in the repository root for full details.

 import {
  type CallMembership,
-  isLivekitTransport,
-  type LivekitTransport,
+  type LivekitTransportConfig,
  type MatrixRTCSession,
  MatrixRTCSessionEvent,
+  isLivekitTransportConfig,
 } from "matrix-js-sdk/lib/matrixrtc";
 import { fromEvent } from "rxjs";

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

-  const transports$ = scope.behavior(
+  const transports$: Behavior<Epoch<LivekitTransportConfig[]>> = scope.behavior(
    membershipsWithTransport$.pipe(
      mapEpoch((mts) => mts.flatMap(({ transport: t }) => (t ? [t] : []))),
    ),