Add support for m.livekit

Merge pull request #4366 from junkerderprovinz/junkerderprovinz/firefox-websocket-prime
Retry the SFU connection once in Firefox when the WebSocket fails
2026-11-01 00:32:28 +00:00 · 2026-10-29 15:40:28 +01:00 · 2026-10-29 08:27:45 +01:00 · 2026-10-29 08:05:07 +01:00 · 2026-10-29 03:19:17 +00:00 · 2026-10-28 23:44:19 +01:00
22 changed files with 501 additions and 178 deletions
@@ -19,7 +19,7 @@ services:
      - ./backend/playwright_homeserver-othersite.yaml:/data/cfg/homeserver.yaml:Z
  element-web:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:ee8ce55012dda2c097147859aece32802ce7a9174e40c3711c56f75ccfe1b169
+    image: ghcr.io/element-hq/element-web:develop@sha256:f4e3c426965bbc96b7b43c2eff9f1dd0e96467508e5aff43b85d2a2cc1226870
  element-web-1:
    # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:ee8ce55012dda2c097147859aece32802ce7a9174e40c3711c56f75ccfe1b169
+    image: ghcr.io/element-hq/element-web:develop@sha256:f4e3c426965bbc96b7b43c2eff9f1dd0e96467508e5aff43b85d2a2cc1226870
@@ -107,7 +107,7 @@
    "livekit-client": "^2.18.1",
    "lodash-es": "^4.17.21",
    "loglevel": "^1.9.1",
-    "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#3f05dc4d104a3dfc753c5e3549a18c74fab4b076",
+    "matrix-js-sdk": "github:matrix-org/matrix-js-sdk#b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2",
    "matrix-widget-api": "^1.18.0",
    "node-stdlib-browser": "^1.3.1",
    "normalize.css": "^8.0.1",
@@ -31,11 +31,7 @@ interface Transport {
 */
 const shapes = {
  url: { type: "livekit", url: sfuUrl },
-  "url+legacy": {
-    type: "livekit",
-    url: sfuUrl,
-    livekit_service_url: serviceUrl,
-  },
+  both: { type: "livekit", url: sfuUrl, livekit_service_url: serviceUrl },
  legacy: null,
 } satisfies Record<string, Transport | null>;
 type Shape = keyof typeof shapes;
@@ -60,15 +56,15 @@ const cases: {
  {
    // Publishers keep the legacy participant identity that clients predating
    // MSC4195 expect, which only the JWT service assigns.
-    hostShape: "url+legacy",
-    guestShape: "url+legacy",
+    hostShape: "both",
+    guestShape: "both",
    hostFlows: ["service-legacy"],
    guestFlows: ["service-legacy"],
  },
  {
    // The MatrixRTC mode has no bearing on the choice.
-    hostShape: "url+legacy",
-    guestShape: "url+legacy",
+    hostShape: "both",
+    guestShape: "both",
    mode: "2_0",
    hostFlows: ["service-legacy"],
    guestFlows: ["service-legacy"],
@@ -79,12 +75,6 @@ const cases: {
    hostFlows: ["cs-api", "service-default"],
    guestFlows: ["service-legacy", "cs-api"],
  },
-  {
-    hostShape: "url",
-    guestShape: "url+legacy",
-    hostFlows: ["cs-api", "service-default"],
-    guestFlows: ["service-legacy", "cs-api"],
-  },
 ];

 for (const { hostShape, guestShape, mode, hostFlows, guestFlows } of cases) {
@@ -136,6 +126,47 @@ for (const { hostShape, guestShape, mode, hostFlows, guestFlows } of cases) {
  });
 }

+test("Subscriber falls back to the JWT service when the homeserver lacks MSC4195", async ({
+  browser,
+  page,
+  browserName,
+}) => {
+  skipOnFirefox(browserName);
+
+  // The host starts the call with both transport shapes.
+  await advertiseTransport(page, shapes.both);
+  await page.goto("/");
+  await SpaHelpers.createCall(page, "Androl", "HelloCall", true);
+  const inviteLink = await SpaHelpers.getCallInviteLink(page);
+
+  // The guest joins but their C-S requests fail.
+  const guestContext = await browser.newContext({ reducedMotion: "reduce" });
+  const guestPage = await guestContext.newPage();
+  await rejectCsApiTokens(guestPage);
+  const guestRequests = recordAuthRequests(guestPage);
+  await SpaHelpers.joinCallFromInviteLink(guestPage, inviteLink, "Pevara");
+
+  // Wait for the call to connect and render.
+  await SpaHelpers.expectVideoTilesCount(page, 2);
+  await SpaHelpers.expectVideoTilesCount(guestPage, 2);
+
+  // The guest ran through all flows.
+  expect(flowsOf(guestRequests)).toEqual(
+    new Set<Flow>(["cs-api", "service-legacy", "service-default"]),
+  );
+
+  // The C-S token requests failed.
+  for (const request of guestRequests) {
+    expect(request.status).toBe(request.flow === "cs-api" ? 404 : 200);
+  }
+
+  // The C-S token requests preceeded the fallback request.
+  const flows = guestRequests.map((r) => r.flow);
+  expect(flows.indexOf("service-default")).toBeGreaterThan(
+    flows.indexOf("cs-api"),
+  );
+});
+
 test("Publisher shows an error when the homeserver lacks MSC4195", async ({
  page,
  browserName,
@@ -167,7 +198,7 @@ test("Publisher shows an error when the homeserver lacks MSC4195", async ({
 const delegationCases: { shape: Shape; via: Delegation["via"] }[] = [
  { shape: "url", via: "homeserver" },
  { shape: "legacy", via: "service" },
-  { shape: "url+legacy", via: "service" },
+  { shape: "both", via: "service" },
 ];

 for (const { shape, via } of delegationCases) {
@@ -11,12 +11,13 @@ import { widgetTest } from "../fixtures/widget-user.ts";
 import { HOST1, TestHelpers } from "./test-helpers.ts";

 const sfuUrl = "wss://matrix-rtc.m.localhost/livekit/sfu";
+const serviceUrl = "https://matrix-rtc.m.localhost/livekit/jwt";

 /** Which endpoint a page asks for its SFU tokens. */
 type Flow = "cs-api" | "service-legacy" | "service-default";

 widgetTest(
-  "Call between a url transport and a legacy one",
+  "Call between a url + livekit_service_url transport and a legacy one",
  async ({ addUser, browserName }) => {
    test.skip(
      browserName === "firefox",
@@ -29,10 +30,12 @@ widgetTest(
      addUser("Pevara", HOST1),
    ]);

-    // Host advertises a url transport, guest still advertises a legacy one
+    // The host's homeserver has started advertising a `url` next to its JWT
+    // service; the guest's still advertises the JWT service alone.
    await advertiseTransport(host.page, {
      type: "livekit",
      url: sfuUrl,
+      livekit_service_url: serviceUrl,
    });
    // Element Web answers the widget from a cache it filled at login, so make
    // it fetch the transports again now that they are rerouted
@@ -64,7 +67,7 @@ widgetTest(
    }

    // Element Web used for Playwright does support MSC4195 for widgets.
-    expect(hostFlows).toEqual(new Set(["cs-api", "service-default"]));
+    expect(hostFlows).toEqual(new Set(["service-legacy", "service-default"]));
    expect(guestFlows).toEqual(new Set(["service-legacy", "cs-api"]));
  },
 );
@@ -66,7 +66,7 @@ importers:
        version: 10.1.2(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@rolldown/plugin-babel':
        specifier: ^0.2.3
-        version: 0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
+        version: 0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.8)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
      '@sentry/react':
        specifier: ^8.0.0
        version: 8.55.2(react@19.2.8)
@@ -138,7 +138,7 @@ importers:
        version: 10.4.0(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.5(@types/react@19.2.18))(@types/react@19.2.18)(@vector-im/compound-design-tokens@11.3.1(@types/react@19.2.18)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
      '@vitejs/plugin-react':
        specifier: ^6.0.2
-        version: 6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
+        version: 6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.8)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
      '@vitest/browser-playwright':
        specifier: ^4.1.5
        version: 4.1.11(playwright@1.62.1)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))(vitest@4.1.11)
@@ -191,8 +191,8 @@ importers:
        specifier: ^1.9.1
        version: 1.9.2
      matrix-js-sdk:
-        specifier: github:matrix-org/matrix-js-sdk#3f05dc4d104a3dfc753c5e3549a18c74fab4b076
-        version: https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/3f05dc4d104a3dfc753c5e3549a18c74fab4b076
+        specifier: github:matrix-org/matrix-js-sdk#b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2
+        version: https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2
      matrix-widget-api:
        specifier: ^1.18.0
        version: 1.20.0
@@ -397,8 +397,8 @@ packages:
    resolution: {integrity: sha512-Nq8OhGWiZIZGV6hLHoyAKLLcJihP/xFeBMGJoUrxTX2psI8dCifzLhZISFb+VWS3wFMRDmCGw5R+dOySCqPLhw==}
    engines: {node: '>=6.9.0'}

-  '@babel/runtime@8.0.0':
-    resolution: {integrity: sha512-sL6cvO2IfkSu/iU+zs2S/w01B7A8V7suXSIKEN4hPFFdZoiPGxrj5pAG0lCaqLWiEIrjKzdznIWuaLcxPR53qw==}
+  '@babel/runtime@8.0.8':
+    resolution: {integrity: sha512-dEu8nGlRqjsJsvviUUoSMfcRHpwomCiRlXsc2mPfJ79+ffTpDm+JtfUtTMzUrqCApHQnCsVPD3gT1ZT8RgBRCQ==}

  '@babel/template@7.29.7':
    resolution: {integrity: sha512-puq+Gf35oI24FeN11LkoUQFqv9uwNeWpxXZi/Ji3rRIoKAzKnxRaZ+Gkj0vKS9ZCiTESfng1N9LyOyXvo+m+Gg==}
@@ -408,10 +408,6 @@ packages:
    resolution: {integrity: sha512-B3lYAs2nkKskbgQ1nfy8Ma9ao9Q1rntTAQHrzzyDuj+TSO+X3le6PfWwqDvodsb+OumE10eMFfuMCTQSQ5iuIQ==}
    engines: {node: '>=6.9.0'}

-  '@babel/traverse@7.29.8':
-    resolution: {integrity: sha512-I5z7H3bf/41ktsNVLtpN0wAa336HkqIHQ5BuPLEhTkt1jVSyZpeNKIzTgEWmlxjdg81R0IgUCcaE+Ok3NvrfZg==}
-    engines: {node: '>=6.9.0'}
-
  '@babel/types@7.29.11':
    resolution: {integrity: sha512-WCsemW40Cpc6gouC1SrY6PBaZ+oLRlEVY9XBvZBI7il/HyUrb2nJ505wE1MHEFyDZNnrWDEuy4jL50WVHfTTSQ==}
    engines: {node: '>=6.9.0'}
@@ -3421,11 +3417,6 @@ packages:
    engines: {node: '>=0.4.0'}
    hasBin: true

-  acorn@8.18.0:
-    resolution: {integrity: sha512-lGq+9yr1/GuAWaVYIHRjvvySG5/4VfKIvC8EWxStPdcDh/Ka7FG3twP6v4d5BkravUilhIAsG4Qj83t02LWUPQ==}
-    engines: {node: '>=0.4.0'}
-    hasBin: true
-
  acorn@8.19.0:
    resolution: {integrity: sha512-oJlA3XiRm7Cyk6qFD2Jn8ak9B7jSy0qy00ADO3+8dpT0LSjFihQYv4C02LFCSYJV3Q37xYwwRy5m+IpIiUzqWw==}
    engines: {node: '>=0.4.0'}
@@ -4759,9 +4750,9 @@ packages:
  matrix-events-sdk@0.0.1:
    resolution: {integrity: sha512-1QEOsXO+bhyCroIe2/A5OwaxHvBm7EsSQ46DEDn8RBIfQwN5HWBpFvyWWR4QY0KHPPnnJdI99wgRiAl7Ad5qaA==}

-  matrix-js-sdk@https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/3f05dc4d104a3dfc753c5e3549a18c74fab4b076:
-    resolution: {gitHosted: true, integrity: sha512-Ly8eS7fNNKDo9KmPvTkE49KvD8iMUmrVWJMNERNuxc8UksMLMG36NLz3fs8HytdwrB7AKPfyVo392VZsxILDIg==, tarball: https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/3f05dc4d104a3dfc753c5e3549a18c74fab4b076}
-    version: 44.0.0
+  matrix-js-sdk@https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2:
+    resolution: {gitHosted: true, integrity: sha512-AXD5ClohyPLBY30QfmkD99fAGlAMsQ+2flR8rWqTy8aNpLHnTUisNhAClDgkAaDTnnFbOX/vZ8hwVzmYSefqTA==, tarball: https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2}
+    version: 45.0.0
    engines: {node: '>=22.0.0'}

  matrix-widget-api@1.20.0:
@@ -6357,10 +6348,10 @@ snapshots:
      '@babel/helper-compilation-targets': 7.29.7
      '@babel/helper-module-transforms': 7.29.7(@babel/core@7.29.7(supports-color@7.2.0))(supports-color@7.2.0)
      '@babel/helpers': 7.29.7
-      '@babel/parser': 7.29.8
+      '@babel/parser': 7.29.11
      '@babel/template': 7.29.7
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
-      '@babel/types': 7.29.8
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
+      '@babel/types': 7.29.11
      '@jridgewell/remapping': 2.3.5
      convert-source-map: 2.0.0
      debug: 4.4.3(supports-color@7.2.0)
@@ -6372,8 +6363,8 @@ snapshots:

  '@babel/generator@7.29.8':
    dependencies:
-      '@babel/parser': 7.29.8
-      '@babel/types': 7.29.8
+      '@babel/parser': 7.29.11
+      '@babel/types': 7.29.11
      '@jridgewell/gen-mapping': 0.3.13
      '@jridgewell/trace-mapping': 0.3.31
      jsesc: 3.1.0
@@ -6390,8 +6381,8 @@ snapshots:

  '@babel/helper-module-imports@7.29.7(supports-color@7.2.0)':
    dependencies:
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
-      '@babel/types': 7.29.8
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
+      '@babel/types': 7.29.11
    transitivePeerDependencies:
      - supports-color

@@ -6400,7 +6391,7 @@ snapshots:
      '@babel/core': 7.29.7(supports-color@7.2.0)
      '@babel/helper-module-imports': 7.29.7(supports-color@7.2.0)
      '@babel/helper-validator-identifier': 7.29.7
-      '@babel/traverse': 7.29.8(supports-color@7.2.0)
+      '@babel/traverse': 7.29.10(supports-color@7.2.0)
    transitivePeerDependencies:
      - supports-color

@@ -6417,7 +6408,7 @@ snapshots:
  '@babel/helpers@7.29.7':
    dependencies:
      '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
+      '@babel/types': 7.29.11

  '@babel/parser@7.29.11':
    dependencies:
@@ -6433,13 +6424,13 @@ snapshots:

  '@babel/runtime@7.29.7': {}

-  '@babel/runtime@8.0.0': {}
+  '@babel/runtime@8.0.8': {}

  '@babel/template@7.29.7':
    dependencies:
      '@babel/code-frame': 7.29.7
-      '@babel/parser': 7.29.8
-      '@babel/types': 7.29.8
+      '@babel/parser': 7.29.11
+      '@babel/types': 7.29.11

  '@babel/traverse@7.29.10(supports-color@7.2.0)':
    dependencies:
@@ -6448,19 +6439,7 @@ snapshots:
      '@babel/helper-globals': 7.29.7
      '@babel/parser': 7.29.11
      '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
-      debug: 4.4.3(supports-color@7.2.0)
-    transitivePeerDependencies:
-      - supports-color
-
-  '@babel/traverse@7.29.8(supports-color@7.2.0)':
-    dependencies:
-      '@babel/code-frame': 7.29.7
-      '@babel/generator': 7.29.8
-      '@babel/helper-globals': 7.29.7
-      '@babel/parser': 7.29.8
-      '@babel/template': 7.29.7
-      '@babel/types': 7.29.8
+      '@babel/types': 7.29.11
      debug: 4.4.3(supports-color@7.2.0)
    transitivePeerDependencies:
      - supports-color
@@ -8167,13 +8146,13 @@ snapshots:
  '@rolldown/binding-win32-x64-msvc@1.2.15':
    optional: true

-  '@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))':
+  '@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.8)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))':
    dependencies:
      '@babel/core': 7.29.7(supports-color@7.2.0)
      picomatch: 4.0.4
      rolldown: 1.2.15
    optionalDependencies:
-      '@babel/runtime': 8.0.0
+      '@babel/runtime': 8.0.8
      vite: 8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)

  '@rolldown/pluginutils@1.0.1': {}
@@ -8925,12 +8904,12 @@ snapshots:
      - '@types/react-dom'
      - react-dom

-  '@vitejs/plugin-react@6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))':
+  '@vitejs/plugin-react@6.1.1(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.8)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))':
    dependencies:
      '@rolldown/pluginutils': 1.0.1
      vite: 8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0)
    optionalDependencies:
-      '@rolldown/plugin-babel': 0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.0)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
+      '@rolldown/plugin-babel': 0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@8.0.8)(rolldown@1.2.15)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))
      babel-plugin-react-compiler: 1.0.0

  '@vitest/browser-playwright@4.1.11(playwright@1.62.1)(vite@8.2.4(@types/node@24.13.3)(esbuild@0.28.2)(jiti@2.7.0)(sass@1.103.1)(terser@5.46.1)(yaml@2.9.0))(vitest@4.1.11)':
@@ -9055,14 +9034,12 @@ snapshots:

  '@webcontainer/env@1.1.1': {}

-  acorn-jsx@5.3.2(acorn@8.18.0):
+  acorn-jsx@5.3.2(acorn@8.19.0):
    dependencies:
-      acorn: 8.18.0
+      acorn: 8.19.0

  acorn@8.16.0: {}

-  acorn@8.18.0: {}
-
  acorn@8.19.0: {}

  agent-base@6.0.2(supports-color@7.2.0):
@@ -9733,8 +9710,8 @@ snapshots:

  espree@9.6.1:
    dependencies:
-      acorn: 8.18.0
-      acorn-jsx: 5.3.2(acorn@8.18.0)
+      acorn: 8.19.0
+      acorn-jsx: 5.3.2(acorn@8.19.0)
      eslint-visitor-keys: 3.4.3

  esprima@4.0.1: {}
@@ -10468,9 +10445,9 @@ snapshots:

  matrix-events-sdk@0.0.1: {}

-  matrix-js-sdk@https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/3f05dc4d104a3dfc753c5e3549a18c74fab4b076:
+  matrix-js-sdk@https://codeload.github.com/matrix-org/matrix-js-sdk/tar.gz/b3f17e3ee8ca53f5625f7d8c482155d5a82ef4a2:
    dependencies:
-      '@babel/runtime': 8.0.0
+      '@babel/runtime': 8.0.8
      '@matrix-org/matrix-sdk-crypto-wasm': 18.9.0
      another-json: 0.2.0
      bs58: 6.0.0
@@ -11701,7 +11678,7 @@ snapshots:
  terser@5.46.1:
    dependencies:
      '@jridgewell/source-map': 0.3.11
-      acorn: 8.18.0
+      acorn: 8.19.0
      commander: 2.20.3
      source-map-support: 0.5.21

@@ -538,7 +538,7 @@ backend is handed the whole session's view and gives back media:
 type MemberMediaFields = Pick<RTCMember, "tracks$" | "encryptionError$">;

 export interface MediaBackend {
-  readonly transportType: string; // "livekit"
+  readonly transportTypes: readonly string[]; // ["m.livekit", "livekit"]
  /** Authenticate with the transport the client found; the probe for delegation runs here. */
  prepareLocalTransport(
    transport: Transport,
@@ -164,7 +164,7 @@ function setup(
    context: MediaBackendContext,
  ): MediaBackend => {
    const backend: MediaBackend = {
-      transportType: "livekit",
+      transportTypes: ["m.livekit", "livekit"],
      prepareLocalTransport: async () => fake.prepared.promise,
      delegateDelayedLeave: fake.delegateDelayedLeave,
      local: {
@@ -136,7 +136,8 @@ export function createRTCParticipation(
  // fallback: another member's SFU may let us publish (MSC4195). LiveKit only,
  // so it stays out of the backend interface
  const transportFromBackends = async (): Promise<Transport | null> =>
-    backend.transportType === "livekit"
+    backend.transportTypes.includes("m.livekit") ||
+    backend.transportTypes.includes("livekit")
      ? findRemotePublishLivekitTransport({
          client,
          // A snapshot: if nobody with a usable SFU is here yet, the user has
@@ -152,7 +153,7 @@ export function createRTCParticipation(
  const preparedTransport$ = from(
    discoverLocalTransport(
      client,
-      backend.transportType,
+      backend.transportTypes,
      options,
      transportFromBackends,
      logger,
@@ -230,7 +230,7 @@ export interface DataMessage {
 * backend-specific developer panel and for connection diagnostics.
 */
 export interface TransportMetadata {
-  /** `"livekit"` today. */
+  /** `"m.livekit"` or `"livekit"` today. */
  type: string;
  /** Stable key, unique per transport in the slot: the raw transport, serialised with sorted keys. */
  id: string;
@@ -48,7 +48,7 @@ describe("discoverLocalTransport", () => {
    await expect(
      discoverLocalTransport(
        c,
-        "livekit",
+        ["m.livekit", "livekit"],
        { transport: hostTransport },
        fromBackends(),
        logger,
@@ -61,7 +61,7 @@ describe("discoverLocalTransport", () => {
    await expect(
      discoverLocalTransport(
        client([homeserverTransport]),
-        "livekit",
+        ["m.livekit", "livekit"],
        { fallbackTransport: hostTransport },
        fromBackends(),
        logger,
@@ -73,7 +73,7 @@ describe("discoverLocalTransport", () => {
    await expect(
      discoverLocalTransport(
        client([{ type: "not_livekit" }]),
-        "livekit",
+        ["m.livekit", "livekit"],
        { fallbackTransport: hostTransport },
        fromBackends(),
        logger,
@@ -87,7 +87,7 @@ describe("discoverLocalTransport", () => {
    await expect(
      discoverLocalTransport(
        client([homeserverTransport]),
-        "livekit",
+        ["m.livekit", "livekit"],
        {},
        backends,
        logger,
@@ -99,7 +99,7 @@ describe("discoverLocalTransport", () => {
  it("fails naming the homeserver where there is no transport at all", async () => {
    const promise = discoverLocalTransport(
      client([]),
-      "livekit",
+      ["m.livekit", "livekit"],
      {},
      fromBackends(),
      logger,
@@ -15,14 +15,15 @@ import { TransportAutoDiscovery } from "./TransportAutoDiscovery";

 /**
 * The transport the local member advertises: the one the host names, else the
- * homeserver's first of the type the backend serves, else the host's fallback,
- * else the first the backends can provide, which are asked only then.
+ * homeserver's first of the most preferred type the backend serves, else the
+ * host's fallback, else the first the backends can provide, which are asked
+ * only then.
 *
 * @throws {MatrixRTCTransportMissingError} where none of these exists.
 */
 export async function discoverLocalTransport(
  client: Pick<MatrixClient, "getDomain" | "_unstable_getRTCTransports">,
-  transportType: string,
+  transportTypes: readonly string[],
  {
    transport: override,
    fallbackTransport,
@@ -34,7 +35,7 @@ export async function discoverLocalTransport(
    override ??
    (await new TransportAutoDiscovery({
      client,
-      transportType,
+      transportTypes,
      fallbackTransport,
      logger,
    }).discoverPreferredTransport()) ??
@@ -61,7 +61,7 @@ describe("TransportAutoDiscovery", () => {

      const discovery = new TransportAutoDiscovery({
        client,
-        transportType: "livekit",
+        transportTypes: ["m.livekit", "livekit"],
        fallbackTransport: configTransport,
        logger: rootLogger,
      });
@@ -75,6 +75,29 @@ describe("TransportAutoDiscovery", () => {
    },
  );

+  it("prefers a transport of an earlier type over one listed before it", async () => {
+    const mLivekit: Transport = {
+      type: "m.livekit",
+      url: "wss://sfu.example.org",
+    };
+    const client = makeClient();
+    client._unstable_getRTCTransports.mockResolvedValue([
+      backendTransport,
+      mLivekit,
+    ]);
+
+    const discovery = new TransportAutoDiscovery({
+      client,
+      transportTypes: ["m.livekit", "livekit"],
+      fallbackTransport: configTransport,
+      logger: rootLogger,
+    });
+
+    await expect(discovery.discoverPreferredTransport()).resolves.toStrictEqual(
+      mLivekit,
+    );
+  });
+
  it("Retries limit_exceeded backend transport", async () => {
    const client = makeClient();
    client._unstable_getRTCTransports
@@ -92,7 +115,7 @@ describe("TransportAutoDiscovery", () => {

    const discovery = new TransportAutoDiscovery({
      client,
-      transportType: "livekit",
+      transportTypes: ["m.livekit", "livekit"],
      fallbackTransport: configTransport,
      logger: rootLogger,
    });
@@ -116,7 +139,7 @@ describe("TransportAutoDiscovery", () => {

      const discovery = new TransportAutoDiscovery({
        client,
-        transportType: "livekit",
+        transportTypes: ["m.livekit", "livekit"],
        fallbackTransport: configTransport,
        logger: rootLogger,
      });
@@ -133,7 +156,7 @@ describe("TransportAutoDiscovery", () => {

    const discovery = new TransportAutoDiscovery({
      client,
-      transportType: "livekit",
+      transportTypes: ["m.livekit", "livekit"],
      fallbackTransport: undefined,
      logger: rootLogger,
    });
@@ -17,27 +17,27 @@ type TransportDiscoveryClient = Pick<

 export interface TransportAutoDiscoveryProps {
  client: TransportDiscoveryClient;
-  /** The transport type the media backend serves. */
-  transportType: string;
-  /** A transport to use when the homeserver advertises none of the type. */
+  /** The transport types the media backend serves, most preferred first. */
+  transportTypes: readonly string[];
+  /** A transport to use when the homeserver advertises none of the types. */
  fallbackTransport?: Transport;
  logger: Logger;
 }

 export class TransportAutoDiscovery {
  private readonly client: TransportDiscoveryClient;
-  private readonly transportType: string;
+  private readonly transportTypes: readonly string[];
  private readonly fallbackTransport: Transport | undefined;
  private readonly logger: Logger;

  public constructor({
    client,
-    transportType,
+    transportTypes,
    fallbackTransport,
    logger,
  }: TransportAutoDiscoveryProps) {
    this.client = client;
-    this.transportType = transportType;
+    this.transportTypes = transportTypes;
    this.fallbackTransport = fallbackTransport;
    this.logger = logger.getChild("[TransportAutoDiscovery]");
  }
@@ -64,7 +64,7 @@ export class TransportAutoDiscovery {
  }

  /**
-   * Fetches the first transport of the backend's type from the homeserver.
+   * Fetches the first transport of the backend's most preferred type from the homeserver.
   * This will not throw errors, but instead just log them and return null if the expected config is not found or malformed.
   * @private
   */
@@ -76,17 +76,16 @@ export class TransportAutoDiscovery {
      const transportList = await doNetworkOperationWithRetry(async () =>
        client._unstable_getRTCTransports(),
      );
-      const first = transportList.find(
-        (transport) => transport.type === this.transportType,
-      );
-      if (first) {
-        return first;
-      } else {
-        this.logger.info(
-          `No ${this.transportType} transport found in getRTCTransports end point`,
-          transportList,
+      for (const type of this.transportTypes) {
+        const first = transportList.find(
+          (transport) => transport.type === type,
        );
+        if (first) return first;
      }
+      this.logger.info(
+        `No ${this.transportTypes.join(" or ")} transport found in getRTCTransports end point`,
+        transportList,
+      );
    } catch (ex) {
      this.logger.info(`Failed to use getRTCTransports end point: ${ex}`);
    }
@@ -113,8 +113,11 @@ export interface DataPacket {
 }

 export interface MediaBackend {
-  /** The membership transport type this backend serves: "livekit". */
-  readonly transportType: string;
+  /**
+   * The membership transport types this backend serves, ordered decreasingly
+   * by preference.
+   */
+  readonly transportTypes: readonly string[];

  /**
   * Makes `transport` usable as the one the local member publishes on. The
@@ -16,6 +16,7 @@ import {
  vi,
 } from "vitest";
 import {
+  ConnectionError,
  type LocalParticipant,
  type RemoteParticipant,
  type RemoteTrack,
@@ -41,7 +42,7 @@ import {
 } from "./Connection.ts";
 import { ObservableScope } from "../../reactive/ObservableScope";
 import { type ClientGetTokenParts, type ClientOpenIDParts } from "./auth";
-import { MatrixRTCError } from "../../errors";
+import { LivekitConnectionError, MatrixRTCError } from "../../errors";
 import { testJWTToken } from "../../utils/test-fixtures";
 import { ownMemberMock } from "../../utils/test";
 import { mockRemoteParticipant } from "./test";
@@ -57,6 +58,10 @@ let fakeLocalParticipant: MockedObject<LocalParticipant>;

 const ROOM_ID = "!roomID:example.org";
 const SLOT_ID = "m.call#ROOM";
+const FIREFOX_USER_AGENT =
+  "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:147.0) Gecko/20100101 Firefox/147.0";
+const CHROME_USER_AGENT =
+  "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/141.0.0.0 Safari/537.36";

 const transport: UnstableLivekitTransport = {
  type: "livekit",
@@ -147,6 +152,13 @@ function setupRemoteConnection(): Connection {
  return new Connection(opts, logger);
 }

+function mockUserAgent(userAgent: string): void {
+  const spy = vi
+    .spyOn(navigator, "userAgent", "get")
+    .mockReturnValue(userAgent);
+  onTestFinished(() => spy.mockRestore());
+}
+
 afterEach(() => {
  vi.useRealTimers();
  vi.clearAllMocks();
@@ -375,6 +387,89 @@ describe("Start connection states", () => {
    expect(connection.livekitAlias).toBe("!example_room_id");
  });

+  it("retries a join that failed on the WebSocket in Firefox", async () => {
+    setupTest();
+    mockUserAgent(FIREFOX_USER_AGENT);
+    const connection = setupRemoteConnection();
+    const capturedStates: ConnectionState[] = [];
+    const s = connection.state$.subscribe((value) => {
+      capturedStates.push(value);
+    });
+    onTestFinished(() => s.unsubscribe());
+    const firstJoin = Promise.withResolvers<void>();
+    fakeLivekitRoom.connect.mockReturnValueOnce(firstJoin.promise);
+
+    const started = connection.start();
+    await vi.waitFor(() => expect(fakeLivekitRoom.connect).toHaveBeenCalled());
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(1);
+    firstJoin.reject(ConnectionError.websocket("WS closed unexpectedly"));
+    await started;
+
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(2);
+    expect(capturedStates.at(-1)).toEqual({
+      state: "authenticated",
+      livekitState: LivekitConnectionState.Connected,
+    });
+    expect(capturedStates.some((st) => st.state === "error")).toBe(false);
+  });
+
+  it("retries a join in Firefox only once", async () => {
+    setupTest();
+    mockUserAgent(FIREFOX_USER_AGENT);
+    const connection = setupRemoteConnection();
+    fakeLivekitRoom.connect.mockRejectedValue(
+      ConnectionError.websocket("WS closed unexpectedly"),
+    );
+
+    await expect(connection.start()).rejects.toThrow(LivekitConnectionError);
+
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(2);
+  });
+
+  it("does not retry a join that failed for another reason in Firefox", async () => {
+    setupTest();
+    mockUserAgent(FIREFOX_USER_AGENT);
+    const connection = setupRemoteConnection();
+    fakeLivekitRoom.connect.mockRejectedValueOnce(
+      ConnectionError.serverUnreachable("server was not reachable"),
+    );
+
+    await expect(connection.start()).rejects.toThrow(LivekitConnectionError);
+
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(1);
+  });
+
+  it("does not retry a join that failed on the WebSocket in other browsers", async () => {
+    setupTest();
+    mockUserAgent(CHROME_USER_AGENT);
+    const connection = setupRemoteConnection();
+    fakeLivekitRoom.connect.mockRejectedValueOnce(
+      ConnectionError.websocket("WS closed unexpectedly"),
+    );
+
+    await expect(connection.start()).rejects.toThrow(LivekitConnectionError);
+
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(1);
+  });
+
+  it("does not retry a join in Firefox once stopped", async () => {
+    setupTest();
+    mockUserAgent(FIREFOX_USER_AGENT);
+    const connection = setupRemoteConnection();
+    const firstJoin = Promise.withResolvers<void>();
+    fakeLivekitRoom.connect.mockReturnValueOnce(firstJoin.promise);
+    fakeLivekitRoom.disconnect.mockResolvedValue(undefined);
+
+    const started = connection.start();
+    await vi.waitFor(() => expect(fakeLivekitRoom.connect).toHaveBeenCalled());
+    const stopping = connection.stop();
+    firstJoin.reject(ConnectionError.websocket("WS closed unexpectedly"));
+    await stopping;
+
+    await expect(started).resolves.toBeUndefined();
+    expect(fakeLivekitRoom.connect).toHaveBeenCalledTimes(1);
+  });
+
  it("stopping while connecting does not report an error", async () => {
    setupTest();
    const connection = setupRemoteConnection();
@@ -14,6 +14,7 @@ import {
  ConnectionError,
  ConnectionErrorReason,
  type ConnectionState as LivekitConnectionState,
+  getBrowser,
  type Participant,
  type RemoteParticipant,
  type RemoteTrackPublication,
@@ -322,7 +323,7 @@ export class Connection {

      try {
        this.logger.info(`livekitRoom.connect ${url}`);
-        await this.livekitRoom.connect(url, jwt);
+        await this.connectLivekitRoom(url, jwt);
        this.logger.info(`livekitRoom.connect SUCCESS ${url}`);
      } catch (e) {
        this.logger.info(`livekitRoom.connect FAILED ${url}`, e);
@@ -382,6 +383,23 @@ export class Connection {
    }
  }

+  private async connectLivekitRoom(url: string, jwt: string): Promise<void> {
+    try {
+      await this.livekitRoom.connect(url, jwt);
+    } catch (e) {
+      // Behind a proxy, Firefox fails the first WebSocket to a host after trying
+      // it over HTTP/2, so a join that fails on the WebSocket gets a second try.
+      // https://bugzilla.mozilla.org/show_bug.cgi?id=2015411
+      const failedOnFirefoxWebSocket =
+        getBrowser()?.name === "Firefox" &&
+        e instanceof ConnectionError &&
+        e.reason === ConnectionErrorReason.WebSocket;
+      if (this.stopped || !failedOnFirefoxWebSocket) throw e;
+      this.logger.info(`livekitRoom.connect RETRY ${url}`, e);
+      await this.livekitRoom.connect(url, jwt);
+    }
+  }
+
  protected async getSFUConfig(): Promise<SFUConfig> {
    return await getSFUConfig({
      client: this.client,
@@ -166,8 +166,9 @@ export function createLivekitBackend(
      );
      canDelegate = Promise.resolve(false);
    } else {
-      // Check for support using the same auth flow that we intend to use later
-      const flow = chooseAuthFlow(transport);
+      // Delegation goes through whichever service authenticates us as a
+      // publisher, so only that service's support counts
+      const flow = chooseAuthFlow(transport, "publisher");
      canDelegate =
        flow.kind === "openID"
          ? supportsDelegation(
@@ -270,7 +271,7 @@ export function createLivekitBackend(
  });

  return {
-    transportType: "livekit",
+    transportTypes: ["m.livekit", "livekit"],
    prepareLocalTransport,
    delegateDelayedLeave: delegateLeave,
    local: localMedia_,
@@ -13,6 +13,7 @@ import {
 } from "matrix-js-sdk/lib/matrixrtc";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";

+import { serverNameOfTransport } from "../../utils/serverName";
 import { isCsApiUnavailable } from "./auth";
 import * as csApi from "./auth/csApi";
 import { decodeSFUJWTPayload } from "./auth/types";
@@ -59,7 +60,7 @@ export async function findRemotePublishLivekitTransport({
      if (!isUnstableLivekitTransport(transport) || !("url" in transport))
        continue;
      const { url } = transport;
-      const serverName = membership.getTransportServerName(transport);
+      const serverName = serverNameOfTransport(transport, membership.userId);
      const key = JSON.stringify([url, serverName]);
      if (tried.has(key)) continue;
      tried.add(key);
@@ -7,7 +7,7 @@ Please see LICENSE in the repository root for full details.

 import { afterEach, describe, expect, it, type Mocked, vi } from "vitest";
 import fetchMock from "fetch-mock";
-import { MatrixError } from "matrix-js-sdk";
+import { ConnectionError, MatrixError } from "matrix-js-sdk";
 import { logger } from "matrix-js-sdk/lib/logger";
 import { type UnstableLivekitTransport } from "matrix-js-sdk/lib/matrixrtc";
 import { type CallMembershipIdentityParts } from "matrix-js-sdk/lib/matrixrtc/EncryptionManager";
@@ -144,8 +144,26 @@ describe("getSFUConfig", () => {
    expect(jwtServiceCalls()).toEqual(["/get_token"]);
  });

-  it("uses OpenID when subscribing with url + livekit_service_url transport", async () => {
+  it("uses CS API when subscribing with url + livekit_service_url transport", async () => {
    mockJWTService();
+    expect(
+      await getSFUConfig({
+        ...defaultParams,
+        transport: urlAndServiceUrlTransport,
+      }),
+    ).toEqual(
+      expect.objectContaining({
+        jwt: csApiJWTToken,
+        livekitAlias: "via CS API",
+      }),
+    );
+    expect(client._unstable_getLivekitToken).toHaveBeenCalled();
+    expect(jwtServiceCalls()).toEqual([]);
+  });
+
+  it("falls back to OpenID with url + livekit_service_url transport", async () => {
+    mockJWTService();
+    client._unstable_getLivekitToken.mockRejectedValueOnce(unsupportedError);
    expect(
      await getSFUConfig({
        ...defaultParams,
@@ -157,7 +175,25 @@ describe("getSFUConfig", () => {
        livekitAlias: "via default endpoint",
      }),
    );
-    expect(client._unstable_getLivekitToken).not.toHaveBeenCalled();
+    expect(client._unstable_getLivekitToken).toHaveBeenCalled();
+    expect(jwtServiceCalls()).toEqual(["/get_token"]);
+  });
+
+  it("falls back to OpenID when the widget host refuses the CS API", async () => {
+    mockJWTService();
+    // In widget mode a host without MSC4533 rejects the request before it
+    // reaches the homeserver, with a plain error rather than a Matrix error
+    client._unstable_getLivekitToken.mockRejectedValueOnce(
+      new Error(
+        "The rtc_livekit_get_token action is not supported by the client.",
+      ),
+    );
+    expect(
+      await getSFUConfig({
+        ...defaultParams,
+        transport: urlAndServiceUrlTransport,
+      }),
+    ).toEqual(expect.objectContaining({ jwt: defaultJWTToken }));
    expect(jwtServiceCalls()).toEqual(["/get_token"]);
  });

@@ -186,7 +222,7 @@ describe("getSFUConfig", () => {
    expect(jwtServiceCalls()).toEqual([]);
  });

-  it("does not fall back to OpenID when publishing with url transport", async () => {
+  it("does not fall back to OpenID when publishing", async () => {
    mockJWTService();
    client._unstable_getLivekitToken.mockRejectedValueOnce(unsupportedError);
    await expect(
@@ -219,6 +255,33 @@ describe("getSFUConfig", () => {
    expect(client._unstable_getLivekitToken).not.toHaveBeenCalled();
    expect(jwtServiceCalls()).toEqual(["/sfu/get"]);
  });
+
+  it("does not fall back to OpenID on connection error", async () => {
+    vi.useFakeTimers();
+    try {
+      mockJWTService();
+      const client_ = {
+        ...client,
+        _unstable_getLivekitToken: vi
+          .fn()
+          .mockRejectedValue(new ConnectionError("No connection")),
+      };
+      await Promise.all([
+        expect(
+          getSFUConfig({
+            ...defaultParams,
+            client: client_,
+            transport: urlAndServiceUrlTransport,
+          }),
+        ).rejects.toThrow(expect.any(ConnectionError)),
+        vi.runAllTimersAsync(), // Allow request to be retried
+      ]);
+      expect(client_._unstable_getLivekitToken).toHaveBeenCalled();
+      expect(jwtServiceCalls()).toEqual([]);
+    } finally {
+      vi.useRealTimers();
+    }
+  });
 });

 describe("delegateDelayedLeave", () => {
@@ -299,21 +362,46 @@ describe("delegateDelayedLeave", () => {

 describe("chooseAuthFlow", () => {
  it.each([
-    ["url", urlTransport, { kind: "csApi", url: urlTransport.url }],
+    [
+      "url",
+      "publisher",
+      urlTransport,
+      { kind: "csApi", url: urlTransport.url },
+    ],
+    [
+      "url",
+      "subscriber",
+      urlTransport,
+      { kind: "csApi", url: urlTransport.url },
+    ],
    [
      "livekit_service_url",
+      "publisher",
+      serviceUrlTransport,
+      { kind: "openID", serviceUrl },
+    ],
+    [
+      "livekit_service_url",
+      "subscriber",
      serviceUrlTransport,
      { kind: "openID", serviceUrl },
    ],
    [
      "url + livekit_service_url",
+      "publisher",
      urlAndServiceUrlTransport,
      { kind: "openID", serviceUrl },
    ],
+    [
+      "url + livekit_service_url",
+      "subscriber",
+      urlAndServiceUrlTransport,
+      { kind: "csApi", url: urlTransport.url },
+    ],
  ] as const)(
    "chooses the flow for a %s transport as %s",
-    (_shape, transport, flow) => {
-      expect(chooseAuthFlow(transport)).toEqual(flow);
+    (_shape, role, transport, flow) => {
+      expect(chooseAuthFlow(transport, role)).toEqual(flow);
    },
  );
 });
@@ -65,10 +65,7 @@ export interface GetSFUConfigParams {
  logger: Logger;
 }

-/**
- * Gets an {@link SFUConfig} appropriate for connecting to a given transport,
- * using whichever auth flow is appropriate.
- */
+/** Authenticates with a transport, through whichever flow suits it and our role. */
 export async function getSFUConfig({
  client,
  membership,
@@ -79,36 +76,48 @@ export async function getSFUConfig({
  role,
  logger,
 }: GetSFUConfigParams): Promise<SFUConfig> {
-  const flow = chooseAuthFlow(transport);
-  if (flow.kind === "openID") {
-    return await openID.getSFUConfig({
+  const viaOpenID = async (serviceUrl: string): Promise<SFUConfig> =>
+    await openID.getSFUConfig({
      client,
      membership,
-      serviceUrl: flow.serviceUrl,
+      serviceUrl,
      roomId,
      slotId,
      role,
      logger,
    });
-  } else {
-    try {
-      return await csApi.getSFUConfig({
-        client,
-        membership,
-        url: flow.url,
-        serverName,
-        roomId,
-        slotId,
-      });
-    } catch (e) {
-      if (isEndpointUnsupported(e)) {
-        logger.error(
-          `Homeserver does not support the MSC4195 get_token endpoint, cannot get token for transport ${flow.url}`,
-        );
-        throw new NoMatrix2AuthorizationService(e as Error);
-      }
-      throw e;
+
+  const flow = chooseAuthFlow(transport, role);
+  if (flow.kind === "openID") return await viaOpenID(flow.serviceUrl);
+
+  try {
+    return await csApi.getSFUConfig({
+      client,
+      membership,
+      url: flow.url,
+      serverName,
+      roomId,
+      slotId,
+    });
+  } catch (e) {
+    // A publisher never falls back: a homeserver that advertises a `url` but
+    // does not implement MSC4195 is misconfigured, and the admin should hear
+    // about it before `livekit_service_url` is deprecated
+    const mayFallBack =
+      role === "subscriber" && "livekit_service_url" in transport;
+    if (mayFallBack && isCsApiUnavailable(e)) {
+      logger.warn(
+        `Cannot use the MSC4195 get_token endpoint (${e}), falling back to the OpenID flow with service ${transport.livekit_service_url}`,
+      );
+      return await viaOpenID(transport.livekit_service_url);
    }
+    if (isEndpointUnsupported(e)) {
+      logger.error(
+        `Homeserver does not support the MSC4195 get_token endpoint, cannot get token for transport ${flow.url}`,
+      );
+      throw new NoMatrix2AuthorizationService(e as Error);
+    }
+    throw e;
  }
 }

@@ -140,7 +149,7 @@ export async function delegateDelayedLeave({
  delayTimeoutMs,
  logger,
 }: DelegateDelayedLeaveParams): Promise<void> {
-  const flow = chooseAuthFlow(transport);
+  const flow = chooseAuthFlow(transport, "publisher");
  if (flow.kind === "csApi") {
    try {
      await csApi.delegateDelayedLeave({
@@ -181,18 +190,23 @@ export type AuthFlow =
  | { kind: "openID"; serviceUrl: string };

 /**
- * Chooses which auth flow to use for a given transport. For now this returns a
- * single auth flow, with no provision for a fallback behavior.
+ * Chooses between the MSC4195 client-server API and the OpenID flow against
+ * the transport's JWT service.
+ *
+ * Only the JWT service's `/sfu/get` endpoint assigns the legacy participant
+ * identity that clients predating MSC4195 expect from anyone advertising a
+ * membership, so a publisher keeps using the JWT service wherever the
+ * transport still offers one, even next to a `url`. A subscriber may use the
+ * client-server API regardless, as nobody matches its identity.
 */
-export function chooseAuthFlow(transport: UnstableLivekitTransport): AuthFlow {
-  if ("url" in transport && !("livekit_service_url" in transport))
-    return { kind: "csApi", url: transport.url };
-  // All other transports use the OpenID flow, even if they contain a `url`.
-  // This is necessary since the auth flow determines the participant identity
-  // format, and we still have older clients out in the wild which would not yet
-  // know to look for a hashed participant identity in case `url` is present in
-  // someone else's transport.
-  // TODO: Once users have updated their clients, choose the CS API flow if
-  // available, keeping OpenID as a fallback.
+export function chooseAuthFlow(
+  transport: UnstableLivekitTransport,
+  role: ConnectionRole,
+): AuthFlow {
+  if ("url" in transport) {
+    const useCsApi =
+      !("livekit_service_url" in transport) || role === "subscriber";
+    if (useCsApi) return { kind: "csApi", url: transport.url };
+  }
  return { kind: "openID", serviceUrl: transport.livekit_service_url };
 }
@@ -5,11 +5,24 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */

-import { afterEach, describe, expect, test } from "vitest";
+import { afterEach, describe, expect, test, vi } from "vitest";
+import { act, renderHook } from "@testing-library/react";
+import { E2eeType } from "@element-hq/matrixrtc-sdk";

-import { getKeyForRoom, saveKeyForRoom } from "./sharedKeyManagement";
+import {
+  getKeyForRoom,
+  saveKeyForRoom,
+  useRoomEncryptionSystem,
+} from "./sharedKeyManagement";
+
+vi.mock("../ClientContext", () => {
+  const room = { hasEncryptionStateEvent: (): boolean => false };
+  const client = { getRoom: (): typeof room => room };
+  return { useClient: (): { client: typeof client } => ({ client }) };
+});

 const roomId = "!room:example.org";
+const otherRoomId = "!other:example.org";

 describe("getKeyForRoom", () => {
  afterEach(() => {
@@ -33,4 +46,58 @@ describe("getKeyForRoom", () => {
  test("has no key to offer for a room it has never seen", () => {
    expect(getKeyForRoom(roomId)).toBeNull();
  });
+
+  test("prefers the stored key when the parameters are for another room", () => {
+    saveKeyForRoom(roomId, "stored");
+    window.location.hash = `#?roomId=${encodeURIComponent(otherRoomId)}&password=other-room`;
+
+    expect(getKeyForRoom(roomId)).toBe("stored");
+  });
+
+  test("ignores the password in the parameters for another room", () => {
+    window.location.hash = `#?roomId=${encodeURIComponent(otherRoomId)}&password=other-room`;
+
+    expect(getKeyForRoom(roomId)).toBeNull();
+  });
+});
+
+describe("useRoomEncryptionSystem", () => {
+  afterEach(() => {
+    window.location.hash = "#";
+    localStorage.clear();
+  });
+
+  test("picks up a key saved for the room after it rendered", () => {
+    const { result } = renderHook(() => useRoomEncryptionSystem(roomId));
+    expect(result.current).toEqual({ kind: E2eeType.NONE });
+
+    act(() => saveKeyForRoom(roomId, "stored"));
+
+    expect(result.current).toEqual({
+      kind: E2eeType.SHARED_KEY,
+      secret: "stored",
+    });
+  });
+
+  test("stores a key from the parameters under the room's key only", () => {
+    window.location.hash = `#?roomId=${encodeURIComponent(roomId)}&password=from-the-link`;
+
+    renderHook(() => useRoomEncryptionSystem(roomId));
+
+    expect(Object.keys(localStorage)).toEqual([`room-shared-key-${roomId}`]);
+    expect(getKeyForRoom(roomId)).toBe("from-the-link");
+  });
+
+  test("keeps the stored key when the parameters are for another room", () => {
+    saveKeyForRoom(roomId, "stored");
+    window.location.hash = `#?roomId=${encodeURIComponent(otherRoomId)}&password=other-room`;
+
+    const { result } = renderHook(() => useRoomEncryptionSystem(roomId));
+
+    expect(result.current).toEqual({
+      kind: E2eeType.SHARED_KEY,
+      secret: "stored",
+    });
+    expect(localStorage.getItem(`room-shared-key-${roomId}`)).toBe("stored");
+  });
 });
@@ -59,22 +59,27 @@ const useRoomSharedKey = (

 /**
 * The shared key for a room, preferring one supplied in the parameters Element
- * Call was started with over whatever is in local storage.
+ * Call was started with over whatever is in local storage. If the parameters
+ * are for another room, only the stored key is used, because the password in
+ * the parameters belongs to that other room.
 */
 function keyForRoom(
  roomId: string,
  paramsRoomId: string | null,
  password: string | null,
 ): string | null {
-  if (roomId !== paramsRoomId)
+  const storedKey = localStorage.getItem(
+    getRoomSharedKeyLocalStorageKey(roomId),
+  );
+  if (roomId !== paramsRoomId) {
    logger.warn(
      "requested key for a roomId which is not the current call room id (from the URL)",
      roomId,
      paramsRoomId,
    );
-  return (
-    password ?? localStorage.getItem(getRoomSharedKeyLocalStorageKey(roomId))
-  );
+    return storedKey;
+  }
+  return password ?? storedKey;
 }

 export function getKeyForRoom(roomId: string): string | null {
@@ -89,11 +94,7 @@ export function useRoomEncryptionSystem(roomId: string): EncryptionSystem {
  const { roomId: paramsRoomId, password } = useUrlParams();

  const [storedPassword] = useRoomSharedKey(
-    // TODO: this passes an already-prefixed key where a room ID is expected, so
-    // the local storage key ends up prefixed twice and never matches what
-    // saveKeyForRoom writes. Preserved as-is here to keep this commit a pure
-    // refactor; the reactive read is effectively dead until it is fixed.
-    getRoomSharedKeyLocalStorageKey(roomId),
+    roomId,
    keyForRoom(roomId, paramsRoomId, password) ?? undefined,
  );
Author	SHA1	Message	Date
Johannes Marbach	94ee13c639	Add support for m.livekit	2026-10-29 15:40:28 +01:00
Johannes Marbach	26b09adc64	Merge pull request #4366 from junkerderprovinz/junkerderprovinz/firefox-websocket-prime Retry the SFU connection once in Firefox when the WebSocket fails	2026-10-29 08:27:45 +01:00
Johannes Marbach	b7655417d7	Move comment inline	2026-10-29 08:05:07 +01:00
renovate[bot]	2dd000bab0	Update ghcr.io/element-hq/element-web:develop Docker digest to f4e3c42 (#4385 ) Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>	2026-10-29 03:19:17 +00:00
junkerderprovinz	d6e3fefe82	Retry the join in Firefox instead of priming the WebSocket The second connection only happens when the first one actually failed on the WebSocket. connect() rejects after its socket has failed and the engine is closed, so the retry never overlaps the failing socket.	2026-10-28 23:44:19 +01:00
Johannes Marbach	b7bc218b19	Merge pull request #4367 from RaphaelFakhri/RaphaelFakhri/shared-key-storage-key Read and write the room shared key under its single-prefixed storage key	2026-10-28 16:21:11 +01:00
Raphael Fakhri	85424f76b1	Ignore the URL password when the parameters are for another room	2026-10-28 14:33:07 +00:00
RaphaelFakhri	dc1459e45e	Prefer the stored shared key when the parameters are for another room keyForRoom returned the password from the parameters even when they were for a different room, and useRoomSharedKey then saved it for this room. Use the stored key first in that case, so another room's password can't replace it.	2026-10-26 21:13:23 +00:00
Junker der Provinz	dfff8be38e	Wait for the primed WebSocket to close before connecting	2026-10-26 18:21:19 +01:00
Raphael Fakhri	bda7b86c39	Read and write the room shared key under its single-prefixed storage key	2026-10-22 12:24:39 +00:00
Junker der ProvinzandMarc	ee507ab3ac	Prime the SFU WebSocket in Firefox before connecting Behind a proxy, Firefox fails the first WebSocket it opens to a host, so the first join fails. The livekit-client in the report turned this into an insufficient capacity error; current versions report a generic connection error. Opening a throwaway WebSocket first lets the real connection through. Co-authored-by: Marc <10048869+MarcWadai@users.noreply.github.com>	2026-10-22 11:28:11 +02:00