Add e2e tests for endpoint usage

backend/dev_livekit-othersite.yaml

@@ -6,6 +6,11 @@ rtc:
   port_range_start: 50300
   port_range_end: 50400
   use_external_ip: false
+  # Advertise the loopback address instead of the container IP, which is not
+  # routable from the host when Docker runs in a VM (colima, Docker Desktop).
+  # The browser then reaches the SFU through the published ports. Firefox
+  # ignores loopback candidates, so this only works in Chromium-based browsers.
+  node_ip: 127.0.0.1
 turn:
   enabled: false
   domain: localhost

backend/dev_livekit.yaml

@@ -6,6 +6,11 @@ rtc:
   port_range_start: 50100
   port_range_end: 50200
   use_external_ip: false
+  # Advertise the loopback address instead of the container IP, which is not
+  # routable from the host when Docker runs in a VM (colima, Docker Desktop).
+  # The browser then reaches the SFU through the published ports. Firefox
+  # ignores loopback candidates, so this only works in Chromium-based browsers.
+  node_ip: 127.0.0.1
 turn:
   enabled: false
   domain: localhost

docker-compose-dev.yml

@@ -3,7 +3,8 @@ networks:
 
 services:
   auth-service:
-    image: ghcr.io/element-hq/lk-jwt-service:0.7.0
+    # Need to use rolling main until the `member_id` change has been released.
+    image: ghcr.io/element-hq/lk-jwt-service:latest-ci
     pull_policy: always
     hostname: auth-server
     environment:
@@ -33,7 +34,8 @@ services:
       - ecbackend
 
   auth-service-1:
-    image: ghcr.io/element-hq/lk-jwt-service:0.7.0
+    # Need to use rolling main until the `member_id` change has been released.
+    image: ghcr.io/element-hq/lk-jwt-service:latest-ci
     pull_policy: always
     hostname: auth-server-1
     environment:

playwright/url-transport.spec.ts

@@ -0,0 +1,135 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { expect, type Page, test } from "@playwright/test";
+
+import { SpaHelpers } from "./spa-helpers";
+
+const sfuUrl = "wss://matrix-rtc.m.localhost/livekit/sfu";
+const serviceUrl = "https://matrix-rtc.m.localhost/livekit/jwt";
+
+interface Transport {
+  type: "livekit";
+  url?: string;
+  livekit_service_url?: string;
+}
+
+/**
+ * The transport shapes a homeserver may advertise while migrating to the
+ * latest MSC4195. `legacy` is what the e2e Synapse advertises on its own.
+ */
+const shapes = {
+  url: { type: "livekit", url: sfuUrl },
+  both: { type: "livekit", url: sfuUrl, livekit_service_url: serviceUrl },
+  legacy: null,
+} satisfies Record<string, Transport | null>;
+type Shape = keyof typeof shapes;
+
+/** Which endpoint a page asks for its SFU tokens. */
+type Flow = "cs-api" | "service-legacy" | "service-default";
+
+const pairs: [host: Shape, guest: Shape][] = [
+  ["url", "url"],
+  ["both", "both"],
+  ["url", "legacy"],
+];
+
+for (const [hostShape, guestShape] of pairs) {
+  test(`One to one call with ${hostShape} host and ${guestShape} guest transport`, async ({
+    browser,
+    page,
+    browserName,
+  }) => {
+    test.skip(
+      browserName === "firefox",
+      "The is test is not working on firefox CI environment. No mic/audio device inputs so cam/mic are disabled",
+    );
+
+    await advertiseTransport(page, shapes[hostShape]);
+    const hostRequests = recordAuthRequests(page);
+    await page.goto("/");
+    await SpaHelpers.createCall(page, "Androl", "HelloCall", true, "2_0");
+    const inviteLink = await SpaHelpers.getCallInviteLink(page);
+
+    const guestContext = await browser.newContext({ reducedMotion: "reduce" });
+    const guestPage = await guestContext.newPage();
+    await advertiseTransport(guestPage, shapes[guestShape]);
+    const guestRequests = recordAuthRequests(guestPage);
+    await SpaHelpers.joinCallFromInviteLink(
+      guestPage,
+      inviteLink,
+      "Pevara",
+      "2_0",
+    );
+
+    await SpaHelpers.expectVideoTilesCount(page, 2);
+    await SpaHelpers.expectVideoTilesCount(guestPage, 2);
+
+    expect(hostRequests.flows).toEqual(expectedFlows(hostShape, guestShape));
+    expect(guestRequests.flows).toEqual(expectedFlows(guestShape, hostShape));
+    for (const requests of [hostRequests, guestRequests]) {
+      for (const url of requests.csApiUrls) expect(url).toBe(sfuUrl);
+    }
+  });
+}
+
+/**
+ * A page publishes on its own transport and subscribes on every other
+ * transport in the call, so the flows it uses depend on both shapes.
+ */
+function expectedFlows(own: Shape, peer: Shape): Set<Flow> {
+  const flows = new Set<Flow>([publishFlow(own)]);
+  if (peer !== own) flows.add(subscribeFlow(peer));
+  return flows;
+}
+
+function publishFlow(shape: Shape): Flow {
+  return shape === "legacy" ? "service-legacy" : "cs-api";
+}
+
+function subscribeFlow(shape: Shape): Flow {
+  return shape === "legacy" ? "service-default" : "cs-api";
+}
+
+/**
+ * Replaces the transports the homeserver advertises to this page. The real
+ * response is fetched first so its CORS headers carry over.
+ */
+async function advertiseTransport(
+  page: Page,
+  transport: Transport | null,
+): Promise<void> {
+  if (transport === null) return;
+  await page.route("**/org.matrix.msc4143/rtc/transports", async (route) => {
+    if (route.request().method() !== "GET") return route.continue();
+    const response = await route.fetch();
+    await route.fulfill({ response, json: { rtc_transports: [transport] } });
+  });
+}
+
+interface AuthRequests {
+  flows: Set<Flow>;
+  /** The `url` field of every request to the MSC4195 `get_token` endpoint. */
+  csApiUrls: string[];
+}
+
+function recordAuthRequests(page: Page): AuthRequests {
+  const requests: AuthRequests = { flows: new Set(), csApiUrls: [] };
+  page.on("request", (request) => {
+    if (request.method() !== "POST") return;
+    const url = request.url();
+    if (url.endsWith("/rtc/livekit/get_token")) {
+      requests.flows.add("cs-api");
+      requests.csApiUrls.push((request.postDataJSON() as { url: string }).url);
+    } else if (url.endsWith("/livekit/jwt/sfu/get")) {
+      requests.flows.add("service-legacy");
+    } else if (url.endsWith("/livekit/jwt/get_token")) {
+      requests.flows.add("service-default");
+    }
+  });
+  return requests;
+}