Merge branch 'develop' into toger5/use-relation-based-CallMembership-create-ts

.github/workflows/notify-downstream.yaml

@@ -19,7 +19,7 @@ jobs:
         runs-on: ubuntu-24.04
         steps:
             - name: Notify matrix-react-sdk repo that a new SDK build is on develop so it can CI against it
-              uses: peter-evans/repository-dispatch@ff45666b9427631e3450c54a1bcbee4d9ff4d7c0 # v3
+              uses: peter-evans/repository-dispatch@5fc4efd1a4797ddb68ffd0714a238564e4cc0e6f # v4
               with:
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                   repository: ${{ matrix.repo }}

.github/workflows/release-drafter-workflow.yml

@@ -21,7 +21,7 @@ jobs:
                   ref: staging
                   fetch-depth: 0
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   node-version-file: package.json
                   cache: "yarn"

.github/workflows/release-gitflow.yml

@@ -33,7 +33,7 @@ jobs:
                   sparse-checkout: |
                       scripts/release
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/release-make.yml

@@ -125,7 +125,7 @@ jobs:
                   git config --global user.email "releases@riot.im"
                   git config --global user.name "RiotRobot"
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/release-npm.yml

@@ -25,7 +25,7 @@ jobs:
                   ref: staging
 
             - name: 🔧 Yarn cache
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   registry-url: "https://registry.npmjs.org"

.github/workflows/release.yml

@@ -50,7 +50,7 @@ jobs:
                   ref: staging
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: "lts/*"
@@ -76,7 +76,7 @@ jobs:
               uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
             - name: 🔧 Yarn cache
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/static_analysis.yml

@@ -16,7 +16,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -33,7 +33,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -50,7 +50,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -61,7 +61,7 @@ jobs:
             - name: Build Types
               run: "yarn build:types"
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "npm"
                   node-version-file: "examples/node/package.json"
@@ -85,7 +85,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -102,7 +102,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -127,7 +127,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -147,7 +147,7 @@ jobs:
               with:
                   repository: element-hq/element-web
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: "lts/*"

.github/workflows/tests.yml

@@ -26,7 +26,7 @@ jobs:
 
             - name: Setup Node
               id: setupNode
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: ${{ matrix.node }}

.github/workflows/triage-stale.yml

@@ -12,7 +12,7 @@ jobs:
             issues: write
             pull-requests: write
         steps:
-            - uses: actions/stale@3a9db7e6a41a89f618792c92c0e97cc736e1b13f # v10
+            - uses: actions/stale@5f858e3efba33a5ca4407a664cc011ad407f2008 # v10
               with:
                   operations-per-run: 250
                   days-before-issue-stale: -1

CHANGELOG.md

@@ -1,3 +1,21 @@
+Changes in [39.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.0.0) (2025-10-21)
+==================================================================================================
+## 🚨 BREAKING CHANGES
+
+* [MatrixRTC] Multi SFU support + m.rtc.member event type support ([#5022](https://github.com/matrix-org/matrix-js-sdk/pull/5022)). Contributed by @toger5.
+
+## ✨ Features
+
+* [MatrixRTC] Multi SFU support + m.rtc.member event type support ([#5022](https://github.com/matrix-org/matrix-js-sdk/pull/5022)). Contributed by @toger5.
+* Implement Sticky Events MSC4354 ([#5028](https://github.com/matrix-org/matrix-js-sdk/pull/5028)). Contributed by @Half-Shot.
+* feat(client): allow disabling VoIP support ([#5021](https://github.com/matrix-org/matrix-js-sdk/pull/5021)). Contributed by @pkuzco.
+
+## 🐛 Bug Fixes
+
+* Only use the first 3 viaServers specified ([#5034](https://github.com/matrix-org/matrix-js-sdk/pull/5034)). Contributed by @t3chguy.
+* Fetch the user's device info before processing a verification request ([#5030](https://github.com/matrix-org/matrix-js-sdk/pull/5030)). Contributed by @andybalaam.
+
+
 Changes in [38.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.4.0) (2025-10-07)
 ==================================================================================================
 ## ✨ Features

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "38.4.0",
+    "version": "39.0.0",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=22.0.0"
@@ -97,9 +97,9 @@
         "eslint-config-prettier": "^10.0.0",
         "eslint-import-resolver-typescript": "^4.0.0",
         "eslint-plugin-import": "^2.26.0",
-        "eslint-plugin-jest": "^28.0.0",
+        "eslint-plugin-jest": "^29.0.0",
-        "eslint-plugin-jsdoc": "^50.0.0",
+        "eslint-plugin-jsdoc": "^61.0.0",
-        "eslint-plugin-matrix-org": "2.1.0",
+        "eslint-plugin-matrix-org": "^3.0.0",
         "eslint-plugin-n": "^14.0.0",
         "eslint-plugin-tsdoc": "^0.4.0",
         "eslint-plugin-unicorn": "^56.0.0",

spec/unit/matrix-client.spec.ts

@@ -1053,17 +1053,28 @@ describe("MatrixClient", function () {
             );
         });
 
-        it("can look up delayed events", async () => {
+        describe("lookups", () => {
+            const statuses = [undefined, "scheduled" as const, "finalised" as const];
+            const delayIds = [undefined, "dxyz", ["d123"], ["d456", "d789"]];
+            const inputs = statuses.flatMap((status) =>
+                delayIds.map((delayId) => [status, delayId] as [(typeof statuses)[0], (typeof delayIds)[0]]),
+            );
+            it.each(inputs)("can look up delayed events (status = %s, delayId = %s)", async (status, delayId) => {
                 httpLookups = [
                     {
                         method: "GET",
                         prefix: unstableMSC4140Prefix,
                         path: "/delayed_events",
+                        expectQueryParams: {
+                            status,
+                            delay_id: delayId,
+                        },
                         data: [],
                     },
                 ];
 
-            await client._unstable_getDelayedEvents();
+                await client._unstable_getDelayedEvents(status, delayId);
+            });
         });
 
         it("can update delayed events", async () => {

spec/unit/matrixrtc/MatrixRTCSession.spec.ts

@@ -16,27 +16,30 @@ limitations under the License.
 
 import {
     encodeBase64,
+    type EventTimeline,
     EventType,
     MatrixClient,
+    type MatrixError,
     MatrixEvent,
     RelationType,
-    type MatrixError,
     type Room,
 } from "../../../src";
 import { KnownMembership } from "../../../src/@types/membership";
 import { MatrixRTCSession, MatrixRTCSessionEvent } from "../../../src/matrixrtc/MatrixRTCSession";
 import { Status, type EncryptionKeysEventContent } from "../../../src/matrixrtc/types";
-import { secureRandomString } from "../../../src/randomstring";
 import {
     makeMockEvent,
     makeMockRoom,
     makeKey,
     type MembershipData,
     mockRoomState,
-    rtcMembershipTemplate,
+    mockRTCEvent,
     sessionMembershipTemplate,
+    rtcMembershipTemplate,
 } from "./mocks";
 import { RTCEncryptionManager } from "../../../src/matrixrtc/RTCEncryptionManager.ts";
+import { RoomStickyEventsEvent, type StickyMatrixEvent } from "../../../src/models/room-sticky-events.ts";
+import { StickyEventMembershipManager } from "../../../src/matrixrtc/MembershipManager.ts";
 
 const mockFocus = { type: "livekit", livekit_service_url: "https://test.org" };
 
@@ -66,11 +69,63 @@ describe("MatrixRTCSession", () => {
         sess = undefined;
     });
 
-    describe("roomSessionForRoom", () => {
+    describe.each([
-        it("creates a room-scoped session from room state", async () => {
+        {
-            const mockRoom = makeMockRoom([membershipTemplate]);
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: true,
+            testCreateSticky: false,
+            createWithDefaults: true, // Create MatrixRTCSession with defaults
+        },
+        {
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: true,
+            testCreateSticky: false,
+        },
+        {
+            listenForStickyEvents: false,
+            listenForMemberStateEvents: true,
+            testCreateSticky: false,
+        },
+        {
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: true,
+            testCreateSticky: true,
+        },
+        {
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: false,
+            testCreateSticky: true,
+        },
+    ])(
+        "roomSessionForRoom listenForSticky=$listenForStickyEvents listenForMemberStateEvents=$listenForMemberStateEvents testCreateSticky=$testCreateSticky",
+        (testConfig) => {
+            it(`will ${testConfig.listenForMemberStateEvents ? "" : "NOT"} throw if the room does not have any state stored`, () => {
+                const mockRoom = makeMockRoom([membershipTemplate], testConfig.testCreateSticky);
+                mockRoom.getLiveTimeline.mockReturnValue({
+                    getState: jest.fn().mockReturnValue(undefined),
+                } as unknown as EventTimeline);
+                if (testConfig.listenForMemberStateEvents) {
+                    // eslint-disable-next-line jest/no-conditional-expect
+                    expect(async () => {
+                        await MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, testConfig);
+                    }).toThrow();
+                } else {
+                    // eslint-disable-next-line jest/no-conditional-expect
+                    expect(async () => {
+                        await MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, testConfig);
+                    }).not.toThrow();
+                }
+            });
 
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+            it("creates a room-scoped session from room state", async () => {
+                const mockRoom = makeMockRoom([membershipTemplate], testConfig.testCreateSticky);
+
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships.length).toEqual(1);
                 expect(sess?.memberships[0].slotDescription.id).toEqual("");
                 expect(sess?.memberships[0].scope).toEqual("m.room");
@@ -84,8 +139,13 @@ describe("MatrixRTCSession", () => {
                 const testMembership = Object.assign({}, membershipTemplate, {
                     application: "not-m.call",
                 });
-            const mockRoom = makeMockRoom([testMembership]);
+                const mockRoom = makeMockRoom([testMembership], testConfig.testCreateSticky);
-            const sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                const sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships).toHaveLength(0);
             });
 
@@ -94,8 +154,13 @@ describe("MatrixRTCSession", () => {
                     call_id: "not-empty",
                     scope: "m.room",
                 });
-            const mockRoom = makeMockRoom([testMembership]);
+                const mockRoom = makeMockRoom([testMembership], testConfig.testCreateSticky);
-            const sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                const sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships).toHaveLength(0);
             });
 
@@ -104,19 +169,42 @@ describe("MatrixRTCSession", () => {
                 const expiredMembership = Object.assign({}, membershipTemplate);
                 expiredMembership.expires = 1000;
                 expiredMembership.device_id = "EXPIRED";
-            const mockRoom = makeMockRoom([membershipTemplate, expiredMembership]);
+                const mockRoom = makeMockRoom([membershipTemplate, expiredMembership], testConfig.testCreateSticky);
 
                 jest.advanceTimersByTime(2000);
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships.length).toEqual(1);
                 expect(sess?.memberships[0].deviceId).toEqual("AAAAAAA");
                 jest.useRealTimers();
             });
 
             it("ignores memberships events of members not in the room", async () => {
-            const mockRoom = makeMockRoom([membershipTemplate]);
+                const mockRoom = makeMockRoom([membershipTemplate], testConfig.testCreateSticky);
-            mockRoom.hasMembershipState = (state) => state === KnownMembership.Join;
+                mockRoom.hasMembershipState.mockImplementation((state) => state === KnownMembership.Join);
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships.length).toEqual(0);
+            });
+
+            it("ignores memberships events with no sender", async () => {
+                // Force the sender to be undefined.
+                const mockRoom = makeMockRoom([{ ...membershipTemplate, user_id: "" }], testConfig.testCreateSticky);
+                mockRoom.hasMembershipState.mockImplementation((state) => state === KnownMembership.Join);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships.length).toEqual(0);
             });
 
@@ -126,20 +214,29 @@ describe("MatrixRTCSession", () => {
                 const expiredMembership = Object.assign({}, membershipTemplate);
                 expiredMembership.created_ts = 500;
                 expiredMembership.expires = 1000;
-            const mockRoom = makeMockRoom([expiredMembership]);
+                const mockRoom = makeMockRoom([expiredMembership], testConfig.testCreateSticky);
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships[0].getAbsoluteExpiry()).toEqual(1500);
                 jest.useRealTimers();
             });
 
             it("returns empty session if no membership events are present", async () => {
-            const mockRoom = makeMockRoom([]);
+                const mockRoom = makeMockRoom([], testConfig.testCreateSticky);
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess?.memberships).toHaveLength(0);
             });
 
             it("safely ignores events with no memberships section", async () => {
-            const roomId = secureRandomString(8);
                 const event = {
                     getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
                     getContent: jest.fn().mockReturnValue({}),
@@ -147,10 +244,8 @@ describe("MatrixRTCSession", () => {
                     getTs: jest.fn().mockReturnValue(1000),
                     getLocalAge: jest.fn().mockReturnValue(0),
                 };
-            const mockRoom = {
+                const mockRoom = makeMockRoom([]);
-                ...makeMockRoom([]),
+                mockRoom.getLiveTimeline.mockReturnValue({
-                roomId,
-                getLiveTimeline: jest.fn().mockReturnValue({
                     getState: jest.fn().mockReturnValue({
                         on: jest.fn(),
                         off: jest.fn(),
@@ -167,14 +262,17 @@ describe("MatrixRTCSession", () => {
                             ],
                         ]),
                     }),
-                }),
+                } as unknown as EventTimeline);
-            };
+                sess = await MatrixRTCSession.sessionForSlot(
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom as unknown as Room, callSession);
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess.memberships).toHaveLength(0);
             });
 
             it("safely ignores events with junk memberships section", async () => {
-            const roomId = secureRandomString(8);
                 const event = {
                     getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
                     getContent: jest.fn().mockReturnValue({ memberships: ["i am a fish"] }),
@@ -182,10 +280,8 @@ describe("MatrixRTCSession", () => {
                     getTs: jest.fn().mockReturnValue(1000),
                     getLocalAge: jest.fn().mockReturnValue(0),
                 };
-            const mockRoom = {
+                const mockRoom = makeMockRoom([]);
-                ...makeMockRoom([]),
+                mockRoom.getLiveTimeline.mockReturnValue({
-                roomId,
-                getLiveTimeline: jest.fn().mockReturnValue({
                     getState: jest.fn().mockReturnValue({
                         on: jest.fn(),
                         off: jest.fn(),
@@ -202,9 +298,13 @@ describe("MatrixRTCSession", () => {
                             ],
                         ]),
                     }),
-                }),
+                } as unknown as EventTimeline);
-            };
+                sess = await MatrixRTCSession.sessionForSlot(
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom as unknown as Room, callSession);
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess.memberships).toHaveLength(0);
             });
 
@@ -212,7 +312,12 @@ describe("MatrixRTCSession", () => {
                 const testMembership = Object.assign({}, membershipTemplate);
                 (testMembership.device_id as string | undefined) = undefined;
                 const mockRoom = makeMockRoom([testMembership]);
-            const sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                const sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess.memberships).toHaveLength(0);
             });
 
@@ -220,9 +325,107 @@ describe("MatrixRTCSession", () => {
                 const testMembership = Object.assign({}, membershipTemplate);
                 (testMembership.call_id as string | undefined) = undefined;
                 const mockRoom = makeMockRoom([testMembership]);
-            sess = await MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+                sess = await MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
                 expect(sess.memberships).toHaveLength(0);
             });
+        },
+    );
+
+    describe("roomSessionForRoom combined state", () => {
+        it("perfers sticky events when both membership and sticky events appear for the same user", async () => {
+            // Create a room with identical member state and sticky state for the same user.
+            const mockRoom = makeMockRoom([membershipTemplate]);
+            mockRoom._unstable_getStickyEvents.mockImplementation(() => {
+                const ev = mockRTCEvent(
+                    {
+                        ...membershipTemplate,
+                        msc4354_sticky_key: `_${membershipTemplate.user_id}_${membershipTemplate.device_id}`,
+                    },
+                    mockRoom.roomId,
+                );
+                return [ev as StickyMatrixEvent];
+            });
+
+            // Expect for there to be one membership as the state has been merged down.
+            sess = await MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, {
+                listenForStickyEvents: true,
+                listenForMemberStateEvents: true,
+            });
+            expect(sess?.memberships.length).toEqual(1);
+            expect(sess?.memberships[0].slotDescription.id).toEqual("");
+            expect(sess?.memberships[0].scope).toEqual("m.room");
+            expect(sess?.memberships[0].application).toEqual("m.call");
+            expect(sess?.memberships[0].deviceId).toEqual("AAAAAAA");
+            expect(sess?.memberships[0].isExpired()).toEqual(false);
+            expect(sess?.slotDescription.id).toEqual("");
+        });
+        it("combines sticky and membership events when both exist", async () => {
+            // Create a room with identical member state and sticky state for the same user.
+            const mockRoom = makeMockRoom([membershipTemplate]);
+            const stickyUserId = "@stickyev:user.example";
+            mockRoom._unstable_getStickyEvents.mockImplementation(() => {
+                const ev = mockRTCEvent(
+                    {
+                        ...membershipTemplate,
+                        user_id: stickyUserId,
+                        msc4354_sticky_key: `_${stickyUserId}_${membershipTemplate.device_id}`,
+                    },
+                    mockRoom.roomId,
+                    15000,
+                    Date.now() - 1000, // Sticky event comes first.
+                );
+                return [ev as StickyMatrixEvent];
+            });
+
+            sess = await MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, {
+                listenForStickyEvents: true,
+                listenForMemberStateEvents: true,
+            });
+
+            const memberships = sess.memberships;
+            expect(memberships.length).toEqual(2);
+            expect(memberships[0].sender).toEqual(stickyUserId);
+            expect(memberships[0].slotDescription.id).toEqual("");
+            expect(memberships[0].scope).toEqual("m.room");
+            expect(memberships[0].application).toEqual("m.call");
+            expect(memberships[0].deviceId).toEqual("AAAAAAA");
+            expect(memberships[0].isExpired()).toEqual(false);
+
+            // Then state
+            expect(memberships[1].sender).toEqual(membershipTemplate.user_id);
+
+            expect(sess?.slotDescription.id).toEqual("");
+        });
+        it("handles an incoming sticky event to an existing session", async () => {
+            const mockRoom = makeMockRoom([membershipTemplate]);
+            const stickyUserId = "@stickyev:user.example";
+
+            sess = await MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, {
+                listenForStickyEvents: true,
+                listenForMemberStateEvents: true,
+            });
+            expect(sess.memberships.length).toEqual(1);
+            const stickyEv = mockRTCEvent(
+                {
+                    ...membershipTemplate,
+                    user_id: stickyUserId,
+                    msc4354_sticky_key: `_${stickyUserId}_${membershipTemplate.device_id}`,
+                },
+                mockRoom.roomId,
+                15000,
+                Date.now() - 1000, // Sticky event comes first.
+            ) as StickyMatrixEvent;
+            mockRoom._unstable_getStickyEvents.mockImplementation(() => {
+                return [stickyEv];
+            });
+            mockRoom.emit(RoomStickyEventsEvent.Update, [stickyEv], [], []);
+            expect(sess.memberships.length).toEqual(2);
+        });
         it("fetches related events if needed from room", async () => {
             const testMembership = {
                 ...rtcMembershipTemplate,
@@ -233,9 +436,7 @@ describe("MatrixRTCSession", () => {
 
             const mockRoom = makeMockRoom([testMembership]);
             const now = Date.now();
-            mockRoom.findEventById = jest
+            mockRoom.findEventById.mockImplementation((id) =>
-                .fn()
-                .mockImplementation((id) =>
                 id === "id"
                     ? new MatrixEvent({ content: { ...rtcMembershipTemplate }, origin_server_ts: now + 100 })
                     : undefined,
@@ -254,7 +455,7 @@ describe("MatrixRTCSession", () => {
             const mockRoom = makeMockRoom([testMembership]);
             const now = Date.now();
 
-            mockRoom.findEventById = jest.fn().mockReturnValue(undefined);
+            mockRoom.findEventById.mockReturnValue(undefined);
             client.fetchRoomEvent = jest
                 .fn()
                 .mockResolvedValue({ content: { ...rtcMembershipTemplate }, origin_server_ts: now + 100 });
@@ -391,6 +592,12 @@ describe("MatrixRTCSession", () => {
             expect(sess!.isJoined()).toEqual(true);
         });
 
+        it("uses the sticky events membership manager implementation", () => {
+            sess!.joinRoomSession([mockFocus], mockFocus, { unstableSendStickyEvents: true });
+            expect(sess!.isJoined()).toEqual(true);
+            expect(sess!["membershipManager"] instanceof StickyEventMembershipManager).toEqual(true);
+        });
+
         it("sends a notification when starting a call and emit DidSendCallNotification", async () => {
             // Simulate a join, including the update to the room state
             // Ensure sendEvent returns event IDs so the DidSendCallNotification payload includes them

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -14,18 +14,32 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { ClientEvent, EventTimeline, MatrixClient } from "../../../src";
+import { ClientEvent, EventTimeline, MatrixClient, type Room } from "../../../src";
 import { RoomStateEvent } from "../../../src/models/room-state";
 import { MatrixRTCSessionManager, MatrixRTCSessionManagerEvents } from "../../../src/matrixrtc/MatrixRTCSessionManager";
-import { makeMockRoom, sessionMembershipTemplate, mockRoomState } from "./mocks";
+import { makeMockRoom, type MembershipData, membershipTemplate, mockRoomState, mockRTCEvent } from "./mocks";
 import { logger } from "../../../src/logger";
 
-describe("MatrixRTCSessionManager", () => {
+describe.each([{ eventKind: "sticky" }, { eventKind: "memberState" }])(
+    "MatrixRTCSessionManager ($eventKind)",
+    ({ eventKind }) => {
         let client: MatrixClient;
 
-    beforeEach(async () => {
+        function sendLeaveMembership(room: Room, membershipData: MembershipData[]): void {
+            if (eventKind === "memberState") {
+                mockRoomState(room, [{ user_id: membershipTemplate.user_id }]);
+                const roomState = room.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
+                const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
+                client.emit(RoomStateEvent.Events, membEvent, roomState, null);
+            } else {
+                membershipData.splice(0, 1, { user_id: membershipTemplate.user_id });
+                client.emit(ClientEvent.Event, mockRTCEvent(membershipData[0], room.roomId, 10000));
+            }
+        }
+
+        beforeEach(() => {
             client = new MatrixClient({ baseUrl: "base_url" });
-        await client.matrixRTC.start();
+            client.matrixRTC.start();
         });
 
         afterEach(() => {
@@ -33,20 +47,15 @@ describe("MatrixRTCSessionManager", () => {
             client.matrixRTC.stop();
         });
 
-    it("Fires event when session starts", async () => {
+        it("Fires event when session starts", () => {
             const onStarted = jest.fn();
-        const { promise, resolve } = Promise.withResolvers<void>();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, (...v) => {
-            onStarted(...v);
-            resolve();
-        });
 
             try {
-            const room1 = makeMockRoom([sessionMembershipTemplate]);
+                const room1 = makeMockRoom([membershipTemplate], eventKind === "sticky");
                 jest.spyOn(client, "getRooms").mockReturnValue([room1]);
 
                 client.emit(ClientEvent.Room, room1);
-            await promise;
                 expect(onStarted).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
             } finally {
                 client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
@@ -58,7 +67,7 @@ describe("MatrixRTCSessionManager", () => {
             client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
 
             try {
-            const room1 = makeMockRoom([{ ...sessionMembershipTemplate, application: "m.other" }]);
+                const room1 = makeMockRoom([{ ...membershipTemplate, application: "m.other" }], eventKind === "sticky");
                 jest.spyOn(client, "getRooms").mockReturnValue([room1]);
 
                 client.emit(ClientEvent.Room, room1);
@@ -68,81 +77,62 @@ describe("MatrixRTCSessionManager", () => {
             }
         });
 
-    it("Fires event when session ends", async () => {
+        it("Fires event when session ends", () => {
             const onEnded = jest.fn();
-        const { promise: endPromise, resolve: rEnd } = Promise.withResolvers();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        client.matrixRTC.once(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
+            const membershipData: MembershipData[] = [membershipTemplate];
-        const { promise: startPromise, resolve: rStart } = Promise.withResolvers();
+            const room1 = makeMockRoom(membershipData, eventKind === "sticky");
-        client.matrixRTC.once(MatrixRTCSessionManagerEvents.SessionEnded, rEnd);
-        client.matrixRTC.once(MatrixRTCSessionManagerEvents.SessionStarted, rStart);
-
-        const room1 = makeMockRoom([sessionMembershipTemplate]);
             jest.spyOn(client, "getRooms").mockReturnValue([room1]);
             jest.spyOn(client, "getRoom").mockReturnValue(room1);
-
             client.emit(ClientEvent.Room, room1);
-        await startPromise;
 
-        mockRoomState(room1, [{ user_id: sessionMembershipTemplate.user_id }]);
+            sendLeaveMembership(room1, membershipData);
-        const roomState = room1.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
+
-        const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
-        client.emit(RoomStateEvent.Events, membEvent, roomState, null);
-        await endPromise;
             expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
         });
 
-    it("Fires correctly with for with custom sessionDescription", async () => {
+        it("Fires correctly with custom sessionDescription", () => {
             const onStarted = jest.fn();
             const onEnded = jest.fn();
             // create a session manager with a custom session description
-        const sessionManager = new MatrixRTCSessionManager(logger, client, { id: "test", application: "m.notCall" });
+            const sessionManager = new MatrixRTCSessionManager(logger, client, {
+                id: "test",
+                application: "m.notCall",
+            });
 
             // manually start the session manager (its not the default one started by the client)
-        await sessionManager.start();
+            sessionManager.start();
-        const { promise: startPromise, resolve: rStart } = Promise.withResolvers<void>();
+            sessionManager.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        const { promise: endPromise, resolve: rEnd } = Promise.withResolvers<void>();
+            sessionManager.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
-
-        sessionManager.on(MatrixRTCSessionManagerEvents.SessionEnded, (v) => {
-            onEnded(v);
-            rEnd();
-        });
-        sessionManager.on(MatrixRTCSessionManagerEvents.SessionStarted, (v) => {
-            onStarted(v);
-            rStart();
-        });
 
             try {
-            const room1 = makeMockRoom([{ ...sessionMembershipTemplate, application: "m.other" }]);
+                // Create a session for applicaation m.other, we ignore this session ecause it lacks a call_id
+                const room1MembershipData: MembershipData[] = [{ ...membershipTemplate, application: "m.other" }];
+                const room1 = makeMockRoom(room1MembershipData, eventKind === "sticky");
                 jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-
                 client.emit(ClientEvent.Room, room1);
                 expect(onStarted).not.toHaveBeenCalled();
                 onStarted.mockClear();
 
-            const room2 = makeMockRoom([{ ...sessionMembershipTemplate, application: "m.notCall", call_id: "test" }]);
+                // Create a session for applicaation m.notCall. We expect this call to be tracked because it has a call_id
+                const room2MembershipData: MembershipData[] = [
+                    { ...membershipTemplate, application: "m.notCall", call_id: "test" },
+                ];
+                const room2 = makeMockRoom(room2MembershipData, eventKind === "sticky");
                 jest.spyOn(client, "getRooms").mockReturnValue([room1, room2]);
-
                 client.emit(ClientEvent.Room, room2);
-            await startPromise;
                 expect(onStarted).toHaveBeenCalled();
                 onStarted.mockClear();
 
-            mockRoomState(room2, [{ user_id: sessionMembershipTemplate.user_id }]);
+                // Stop room1's RTC session. Tracked.
                 jest.spyOn(client, "getRoom").mockReturnValue(room2);
-
+                sendLeaveMembership(room2, room2MembershipData);
-            const roomState = room2.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
-            const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
-            client.emit(RoomStateEvent.Events, membEvent, roomState, null);
-            await endPromise;
                 expect(onEnded).toHaveBeenCalled();
                 onEnded.mockClear();
 
-            mockRoomState(room1, [{ user_id: sessionMembershipTemplate.user_id }]);
+                // Stop room1's RTC session. Not tracked.
                 jest.spyOn(client, "getRoom").mockReturnValue(room1);
-
+                sendLeaveMembership(room1, room1MembershipData);
-            const roomStateOther = room1.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
-            const membEventOther = roomStateOther.getStateEvents("org.matrix.msc3401.call.member")[0];
-            client.emit(RoomStateEvent.Events, membEventOther, roomStateOther, null);
                 expect(onEnded).not.toHaveBeenCalled();
             } finally {
                 client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
@@ -153,18 +143,16 @@ describe("MatrixRTCSessionManager", () => {
         it("Doesn't fire event if unrelated sessions ends", () => {
             const onEnded = jest.fn();
             client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        const room1 = makeMockRoom([{ ...sessionMembershipTemplate, application: "m.other_app" }]);
+            const membership: MembershipData[] = [{ ...membershipTemplate, application: "m.other_app" }];
+            const room1 = makeMockRoom(membership, eventKind === "sticky");
             jest.spyOn(client, "getRooms").mockReturnValue([room1]);
             jest.spyOn(client, "getRoom").mockReturnValue(room1);
 
             client.emit(ClientEvent.Room, room1);
 
-        mockRoomState(room1, [{ user_id: sessionMembershipTemplate.user_id }]);
+            sendLeaveMembership(room1, membership);
-
-        const roomState = room1.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
-        const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
-        client.emit(RoomStateEvent.Events, membEvent, roomState, null);
 
             expect(onEnded).not.toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
         });
-});
+    },
+);

spec/unit/matrixrtc/MembershipManager.spec.ts

@@ -23,6 +23,7 @@ import {
     MatrixError,
     UnsupportedDelayedEventsEndpointError,
     type Room,
+    MAX_STICKY_DURATION_MS,
 } from "../../../src";
 import {
     MembershipManagerEvent,
@@ -94,7 +95,9 @@ describe("MembershipManager", () => {
         // Provide a default mock that is like the default "non error" server behaviour.
         (client._unstable_sendDelayedStateEvent as Mock<any>).mockResolvedValue({ delay_id: "id" });
         (client._unstable_updateDelayedEvent as Mock<any>).mockResolvedValue(undefined);
-        (client.sendStateEvent as Mock<any>).mockResolvedValue(undefined);
+        (client._unstable_sendStickyEvent as Mock<any>).mockResolvedValue({ event_id: "id" });
+        (client._unstable_sendStickyDelayedEvent as Mock<any>).mockResolvedValue({ delay_id: "id" });
+        (client.sendStateEvent as Mock<any>).mockResolvedValue({ event_id: "id" });
     });
 
     afterEach(() => {
@@ -152,45 +155,6 @@ describe("MembershipManager", () => {
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
             });
 
-            it("sends a rtc membership event when using `useRtcMemberFormat`", async () => {
-                // Spys/Mocks
-
-                const updateDelayedEventHandle = createAsyncHandle<void>(client._unstable_updateDelayedEvent as Mock);
-
-                // Test
-                const memberManager = new MembershipManager({ useRtcMemberFormat: true }, room, client, callSession);
-                memberManager.join([], focus);
-                // expects
-                await waitForMockCall(client.sendStateEvent, Promise.resolve({ event_id: "id" }));
-                // This should check for send sticky once we merge with the sticky matrixRTC branch.
-                expect(client.sendStateEvent).toHaveBeenCalledWith(
-                    room.roomId,
-                    "org.matrix.msc4143.rtc.member",
-                    {
-                        application: { type: "m.call" },
-                        member: {
-                            user_id: "@alice:example.org",
-                            id: "_@alice:example.org_AAAAAAA_m.call",
-                            device_id: "AAAAAAA",
-                        },
-                        slot_id: "m.call#",
-                        rtc_transports: [focus],
-                        versions: [],
-                        msc4354_sticky_key: "_@alice:example.org_AAAAAAA_m.call",
-                    },
-                    "_@alice:example.org_AAAAAAA_m.call",
-                );
-                updateDelayedEventHandle.resolve?.();
-                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
-                    room.roomId,
-                    { delay: 8000 },
-                    "org.matrix.msc4143.rtc.member",
-                    {},
-                    "_@alice:example.org_AAAAAAA_m.call",
-                );
-                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
-            });
-
             it("reschedules delayed leave event if sending state cancels it", async () => {
                 const memberManager = new MembershipManager(undefined, room, client, callSession);
                 const waitForSendState = waitForMockCall(client.sendStateEvent);
@@ -927,6 +891,63 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).toHaveBeenCalledTimes(0);
         });
     });
+
+    describe("StickyEventMembershipManager", () => {
+        beforeEach(() => {
+            // Provide a default mock that is like the default "non error" server behaviour.
+            (client._unstable_sendStickyDelayedEvent as Mock<any>).mockResolvedValue({ delay_id: "id" });
+            (client._unstable_sendStickyEvent as Mock<any>).mockResolvedValue(undefined);
+        });
+
+        describe("join()", () => {
+            describe("sends an rtc membership event", () => {
+                it("sends a membership event and schedules delayed leave when joining a call", async () => {
+                    const updateDelayedEventHandle = createAsyncHandle<void>(
+                        client._unstable_updateDelayedEvent as Mock,
+                    );
+                    const memberManager = new StickyEventMembershipManager(undefined, room, client, callSession);
+
+                    memberManager.join([], focus);
+
+                    await waitForMockCall(client._unstable_sendStickyEvent, Promise.resolve({ event_id: "id" }));
+                    // Test we sent the initial join
+                    expect(client._unstable_sendStickyEvent).toHaveBeenCalledWith(
+                        room.roomId,
+                        3600000,
+                        null,
+                        "org.matrix.msc4143.rtc.member",
+                        {
+                            application: { type: "m.call" },
+                            member: {
+                                user_id: "@alice:example.org",
+                                id: "_@alice:example.org_AAAAAAA_m.call",
+                                device_id: "AAAAAAA",
+                            },
+                            slot_id: "m.call#",
+                            rtc_transports: [focus],
+                            versions: [],
+                            msc4354_sticky_key: "_@alice:example.org_AAAAAAA_m.call",
+                        },
+                    );
+                    updateDelayedEventHandle.resolve?.();
+
+                    // Ensure we have sent the delayed disconnect event.
+                    expect(client._unstable_sendStickyDelayedEvent).toHaveBeenCalledWith(
+                        room.roomId,
+                        MAX_STICKY_DURATION_MS,
+                        { delay: 8000 },
+                        null,
+                        "org.matrix.msc4143.rtc.member",
+                        {
+                            msc4354_sticky_key: "_@alice:example.org_AAAAAAA_m.call",
+                        },
+                    );
+                    // ..once
+                    expect(client._unstable_sendStickyDelayedEvent).toHaveBeenCalledTimes(1);
+                });
+            });
+        });
+    });
 });
 
 it("Should prefix log with MembershipManager used", async () => {

spec/unit/matrixrtc/mocks.ts

@@ -15,6 +15,7 @@ limitations under the License.
 */
 
 import { EventEmitter } from "stream";
+import { type Mocked } from "jest-mock";
 
 import { EventType, MatrixEvent, type Room, RoomEvent, type MatrixClient } from "../../../src";
 import {
@@ -65,6 +66,8 @@ export type MockClient = Pick<
     | "sendStateEvent"
     | "_unstable_sendDelayedStateEvent"
     | "_unstable_updateDelayedEvent"
+    | "_unstable_sendStickyEvent"
+    | "_unstable_sendStickyDelayedEvent"
     | "cancelPendingEvent"
 >;
 /**
@@ -79,15 +82,19 @@ export function makeMockClient(userId: string, deviceId: string): MockClient {
         cancelPendingEvent: jest.fn(),
         _unstable_updateDelayedEvent: jest.fn(),
         _unstable_sendDelayedStateEvent: jest.fn(),
+        _unstable_sendStickyEvent: jest.fn(),
+        _unstable_sendStickyDelayedEvent: jest.fn(),
     };
 }
 
 export function makeMockRoom(
     membershipData: MembershipData[],
-): Room & { emitTimelineEvent: (event: MatrixEvent) => void } {
+    useStickyEvents = false,
+): Mocked<Room & { emitTimelineEvent: (event: MatrixEvent) => void }> {
     const roomId = secureRandomString(8);
     // Caching roomState here so it does not get recreated when calling `getLiveTimeline.getState()`
-    const roomState = makeMockRoomState(membershipData, roomId);
+    const roomState = makeMockRoomState(useStickyEvents ? [] : membershipData, roomId);
+    const ts = Date.now();
     const room = Object.assign(new EventEmitter(), {
         roomId: roomId,
         hasMembershipState: jest.fn().mockReturnValue(true),
@@ -95,11 +102,17 @@ export function makeMockRoom(
             getState: jest.fn().mockReturnValue(roomState),
         }),
         getVersion: jest.fn().mockReturnValue("default"),
-    }) as unknown as Room;
+        _unstable_getStickyEvents: jest
+            .fn()
+            .mockImplementation(() =>
+                useStickyEvents ? membershipData.map((m) => mockRTCEvent(m, roomId, 10000, ts)) : [],
+            ) as any,
+        findEventById: jest.fn(),
+    });
     return Object.assign(room, {
         emitTimelineEvent: (event: MatrixEvent) =>
             room.emit(RoomEvent.Timeline, event, room, undefined, false, {} as any),
-    });
+    }) as unknown as Mocked<Room & { emitTimelineEvent: (event: MatrixEvent) => void }>;
 }
 
 function makeMockRoomState(membershipData: MembershipData[], roomId: string) {
@@ -143,6 +156,7 @@ export function makeMockEvent(
     roomId: string | undefined,
     content: any,
     timestamp?: number,
+    stateKey?: string,
 ): MatrixEvent {
     return new MatrixEvent({
         event_id: secureRandomString(8),
@@ -151,11 +165,27 @@ export function makeMockEvent(
         content,
         room_id: roomId,
         origin_server_ts: timestamp ?? 0,
+        state_key: stateKey,
     });
 }
 
-export function mockRTCEvent({ user_id: sender, ...membershipData }: MembershipData, roomId: string): MatrixEvent {
+export function mockRTCEvent(
-    return makeMockEvent(EventType.GroupCallMemberPrefix, sender, roomId, membershipData, Date.now());
+    { user_id: sender, ...membershipData }: MembershipData,
+    roomId: string,
+    stickyDuration?: number,
+    timestamp?: number,
+): MatrixEvent {
+    return {
+        ...makeMockEvent(
+            stickyDuration !== undefined ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
+            sender,
+            roomId,
+            membershipData,
+            timestamp,
+            !stickyDuration && "device_id" in membershipData ? `_${sender}_${membershipData.device_id}` : "",
+        ),
+        unstableStickyExpiresAt: stickyDuration,
+    } as unknown as MatrixEvent;
 }
 
 export function mockCallMembership(membershipData: MembershipData, roomId: string): CallMembership {

spec/unit/matrixrtc/types.spec.ts

@@ -0,0 +1,135 @@
+/*
+Copyright 2025 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { type CallMembership } from "../../../src/matrixrtc";
+import { isMyMembership, parseCallNotificationContent } from "../../../src/matrixrtc/types";
+
+describe("types", () => {
+    describe("isMyMembership", () => {
+        it("returns false if userId is different", () => {
+            expect(
+                isMyMembership(
+                    { sender: "@alice:example.org", deviceId: "DEVICE" } as CallMembership,
+                    "@bob:example.org",
+                    "DEVICE",
+                ),
+            ).toBe(false);
+        });
+        it("returns true if userId and device is the same", () => {
+            expect(
+                isMyMembership(
+                    { sender: "@alice:example.org", deviceId: "DEVICE" } as CallMembership,
+                    "@alice:example.org",
+                    "DEVICE",
+                ),
+            ).toBe(true);
+        });
+    });
+});
+
+describe("IRTCNotificationContent", () => {
+    const validBase = Object.freeze({
+        "m.mentions": { user_ids: [], room: true },
+        "notification_type": "notification",
+        "sender_ts": 123,
+        "lifetime": 1000,
+    });
+
+    it("parses valid content", () => {
+        const res = parseCallNotificationContent({ ...validBase });
+        expect(res).toMatchObject(validBase);
+    });
+
+    it("caps lifetime to 90000ms", () => {
+        const res = parseCallNotificationContent({ ...validBase, lifetime: 130000 });
+        expect(res.lifetime).toBe(90000);
+    });
+
+    it("throws on malformed m.mentions", () => {
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                "m.mentions": "not an object",
+            } as any),
+        ).toThrow("malformed m.mentions");
+    });
+
+    it("throws on missing or invalid notification_type", () => {
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                notification_type: undefined,
+            } as any),
+        ).toThrow("Missing or invalid notification_type");
+
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                notification_type: 123 as any,
+            } as any),
+        ).toThrow("Missing or invalid notification_type");
+    });
+
+    it("throws on missing or invalid sender_ts", () => {
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                sender_ts: undefined,
+            } as any),
+        ).toThrow("Missing or invalid sender_ts");
+
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                sender_ts: "123" as any,
+            } as any),
+        ).toThrow("Missing or invalid sender_ts");
+    });
+
+    it("throws on missing or invalid lifetime", () => {
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                lifetime: undefined,
+            } as any),
+        ).toThrow("Missing or invalid lifetime");
+
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                lifetime: "1000" as any,
+            } as any),
+        ).toThrow("Missing or invalid lifetime");
+    });
+
+    it("accepts valid relation (m.reference)", () => {
+        // Note: parseCallNotificationContent currently checks `relation.rel_type` rather than `m.relates_to`.
+        const res = parseCallNotificationContent({
+            ...validBase,
+            relation: { rel_type: "m.reference", event_id: "$ev" },
+        } as any);
+        expect(res).toBeTruthy();
+    });
+
+    it("throws on invalid relation rel_type", () => {
+        expect(() =>
+            parseCallNotificationContent({
+                ...validBase,
+                relation: { rel_type: "m.annotation", event_id: "$ev" },
+            } as any),
+        ).toThrow("Invalid relation");
+    });
+});

spec/unit/models/room-sticky-events.spec.ts

@@ -259,4 +259,164 @@ describe("RoomStickyEvents", () => {
             expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
         });
     });
+
+    describe("handleRedaction", () => {
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+        it("should not emit if the event does not exist in the map", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction("$123456");
+            expect(emitSpy).not.toHaveBeenCalled();
+        });
+        it("should emit a remove when the event exists in the map without a predecessor", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(stickyEvent.event_id);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+        });
+        it("should emit a remove when the event has no sticky key", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(stickyEvent.event_id);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+        });
+        it("should emit an update when the event exists in the map with a predecessor", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(newerEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newerEv }], []);
+        });
+        it("should emit a remove if the previous event has expired", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Expire the older event.
+            jest.advanceTimersByTime(stickyEvent.msc4354_sticky.duration_ms);
+            // Redact the newer event
+            stickyEvents.handleRedaction(newerEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [newerEv]);
+        });
+        it("should recurse the chain of events if the previous event has been redacted", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const middleEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            jest.advanceTimersByTime(1000);
+            const newestEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newest-ev",
+                origin_server_ts: Date.now() + 2000,
+            });
+            stickyEvents.addStickyEvents([ev, middleEv, newestEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Mark the middle event as redacted.
+            middleEv.setUnsigned({
+                redacted_because: {
+                    event_id: "$foo",
+                } as any,
+            });
+            // Redact the newer event
+            stickyEvents.handleRedaction(newestEv.getId()!);
+            // expect immediate transition from newestEv -> ev and skipping middleEv
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newestEv }], []);
+        });
+        it("should revert to the most recent valid event regardless of insertion order", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const middleEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            jest.advanceTimersByTime(1000);
+            const newestEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newest-ev",
+                origin_server_ts: Date.now() + 2000,
+            });
+            // Invert in reverse order, to make sure we retain the older events.
+            stickyEvents.addStickyEvents([newestEv, middleEv, ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Mark the middle event as redacted.
+            middleEv.setUnsigned({
+                redacted_because: {
+                    event_id: "$foo",
+                } as any,
+            });
+            // Redact the newer event
+            stickyEvents.handleRedaction(newestEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newestEv }], []);
+        });
+        it("should handle redaction when using `handleRedaction` with a `MatrixEvent` parameter", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(newerEv);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newerEv }], []);
+        });
+    });
 });

spec/unit/rust-crypto/rust-crypto.spec.ts

@@ -854,9 +854,27 @@ describe("RustCrypto", () => {
         });
     });
 
+    it("getSecretStorageStatus", async () => {
+        const mockSecretStorage = {
+            getDefaultKeyId: jest.fn().mockResolvedValue("blah"),
+            isStored: jest.fn().mockResolvedValue({ blah: {} }),
+        } as unknown as Mocked<ServerSideSecretStorage>;
+        const rustCrypto = await makeTestRustCrypto(undefined, undefined, undefined, mockSecretStorage);
+        await expect(rustCrypto.getSecretStorageStatus()).resolves.toEqual({
+            defaultKeyId: "blah",
+            ready: true,
+            secretStorageKeyValidityMap: {
+                "m.cross_signing.master": true,
+                "m.cross_signing.self_signing": true,
+                "m.cross_signing.user_signing": true,
+            },
+        });
+    });
+
     it("isSecretStorageReady", async () => {
         const mockSecretStorage = {
             getDefaultKeyId: jest.fn().mockResolvedValue(null),
+            isStored: jest.fn().mockResolvedValue(null),
         } as unknown as Mocked<ServerSideSecretStorage>;
         const rustCrypto = await makeTestRustCrypto(undefined, undefined, undefined, mockSecretStorage);
         await expect(rustCrypto.isSecretStorageReady()).resolves.toBe(false);

src/@types/event.ts

@@ -338,6 +338,7 @@ export interface TimelineEvents {
     [M_BEACON.name]: MBeaconEventContent;
     [M_POLL_START.name]: PollStartEventContent;
     [M_POLL_END.name]: PollEndEventContent;
+    [EventType.RTCMembership]: RtcMembershipData | { msc4354_sticky_key: string }; // An object containing just the sticky key is empty.
 }
 
 /**

src/@types/requests.ts

@@ -20,6 +20,7 @@ import { type IEventWithRoomId, type SearchKey } from "./search.ts";
 import { type IRoomEventFilter } from "../filter.ts";
 import { type Direction } from "../models/event-timeline.ts";
 import { type PushRuleAction } from "./PushRules.ts";
+import { type MatrixError } from "../matrix.ts";
 import { type IRoomEvent } from "../sync-accumulator.ts";
 import { type EventType, type RelationType, type RoomType } from "./event.ts";
 
@@ -136,12 +137,22 @@ type DelayedPartialStateEvent = DelayedPartialTimelineEvent & {
 
 type DelayedPartialEvent = DelayedPartialTimelineEvent | DelayedPartialStateEvent;
 
-export type DelayedEventInfo = {
+export type DelayedEventInfoItem = DelayedPartialEvent &
-    delayed_events: (DelayedPartialEvent &
     SendDelayedEventResponse &
     SendDelayedEventRequestOpts & {
         running_since: number;
-        })[];
+    };
+
+export type DelayedEventInfo = {
+    scheduled?: DelayedEventInfoItem[];
+    finalised?: {
+        delayed_event: DelayedEventInfoItem;
+        outcome: "send" | "cancel";
+        reason: "error" | "action" | "delay";
+        error?: MatrixError["data"];
+        event_id?: string;
+        origin_server_ts?: number;
+    }[];
     next_batch?: string;
 };
 

src/client.ts

@@ -3537,13 +3537,17 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     /**
-     * Get all pending delayed events for the calling user.
+     * Get information about delayed events owned by the requesting user.
      *
      * Note: This endpoint is unstable, and can throw an `Error`.
      *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
      */
     // eslint-disable-next-line
-    public async _unstable_getDelayedEvents(fromToken?: string): Promise<DelayedEventInfo> {
+    public async _unstable_getDelayedEvents(
+        status?: "scheduled" | "finalised",
+        delayId?: string | string[],
+        fromToken?: string,
+    ): Promise<DelayedEventInfo> {
         if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
             throw new UnsupportedDelayedEventsEndpointError(
                 "Server does not support the delayed events API",
@@ -3551,7 +3555,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             );
         }
 
-        const queryDict = fromToken ? { from: fromToken } : undefined;
+        const queryDict = {
+            from: fromToken,
+            status,
+            delay_id: delayId,
+        };
         return await this.http.authedRequest(Method.Get, "/delayed_events", queryDict, undefined, {
             prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
         });

src/crypto-api/index.ts

@@ -20,7 +20,7 @@ import type { ToDeviceBatch, ToDevicePayload } from "../models/ToDeviceMessage.t
 import { type Room } from "../models/room.ts";
 import { type DeviceMap } from "../models/device.ts";
 import { type UIAuthCallback } from "../interactive-auth.ts";
-import { type PassphraseInfo, type SecretStorageKeyDescription } from "../secret-storage.ts";
+import { type PassphraseInfo, type SecretStorageKey, type SecretStorageKeyDescription } from "../secret-storage.ts";
 import { type VerificationRequest } from "./verification.ts";
 import {
     type BackupTrustInfo,
@@ -369,6 +369,11 @@ export interface CryptoApi {
      */
     isSecretStorageReady(): Promise<boolean>;
 
+    /**
+     * Inspect the status of secret storage, in more detail than {@link isSecretStorageReady}.
+     */
+    getSecretStorageStatus(): Promise<SecretStorageStatus>;
+
     /**
      * Bootstrap [secret storage](https://spec.matrix.org/v1.12/client-server-api/#storage).
      *
@@ -1148,6 +1153,30 @@ export interface CryptoCallbacks {
     cacheSecretStorageKey?: (keyId: string, keyInfo: SecretStorageKeyDescription, key: Uint8Array) => void;
 }
 
+/**
+ * The result of a call to {@link CryptoApi.getSecretStorageStatus}.
+ */
+export interface SecretStorageStatus {
+    /** Whether secret storage is fully populated. The same as {@link CryptoApi.isSecretStorageReady}. */
+    ready: boolean;
+
+    /** The ID of the current default secret storage key. */
+    defaultKeyId: string | null;
+
+    /**
+     * For each secret that we checked whether it is correctly stored in secret storage with the default secret storage key.
+     *
+     * Note that we will only check that the key backup key is stored if key backup is currently enabled (i.e. that
+     * {@link CryptoApi.getActiveSessionBackupVersion} returns non-null). `m.megolm_backup.v1` will only be present in that case.
+     *
+     * (This is an object rather than a `Map` so that it JSON.stringify()s nicely, since its main purpose is to end up
+     * in logs.)
+     */
+    secretStorageKeyValidityMap: {
+        [P in SecretStorageKey]?: boolean;
+    };
+}
+
 /**
  * Parameter of {@link CryptoApi#bootstrapSecretStorage}
  */

src/matrixrtc/CallMembership.ts

@@ -194,6 +194,10 @@ export type SessionMembershipData = {
      * something else.
      */
     "m.call.intent"?: RTCCallIntent;
+    /**
+     * The sticky key in case of a sticky event. This string encodes the application + device_id indicating the used slot + device.
+     */
+    "msc4354_sticky_key"?: string;
 };
 
 const checkSessionsMembershipData = (data: IContent, errors: string[]): data is SessionMembershipData => {

src/matrixrtc/MatrixRTCSession.ts

@@ -17,7 +17,6 @@ limitations under the License.
 import { type Logger, logger as rootLogger } from "../logger.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
 import { EventTimeline } from "../models/event-timeline.ts";
-import { MatrixEvent } from "../models/event.ts";
 import { type Room } from "../models/room.ts";
 import { type MatrixClient } from "../client.ts";
 import { EventType, RelationType } from "../@types/event.ts";
@@ -25,7 +24,7 @@ import { KnownMembership } from "../@types/membership.ts";
 import { type ISendEventResponse } from "../@types/requests.ts";
 import { CallMembership } from "./CallMembership.ts";
 import { RoomStateEvent } from "../models/room-state.ts";
-import { MembershipManager } from "./MembershipManager.ts";
+import { MembershipManager, StickyEventMembershipManager } from "./MembershipManager.ts";
 import { EncryptionManager, type IEncryptionManager } from "./EncryptionManager.ts";
 import { deepCompare, logDurationSync } from "../utils.ts";
 import type {
@@ -51,6 +50,8 @@ import {
 } from "./RoomAndToDeviceKeyTransport.ts";
 import { TypedReEmitter } from "../ReEmitter.ts";
 import { ToDeviceKeyTransport } from "./ToDeviceKeyTransport.ts";
+import { MatrixEvent } from "../models/event.ts";
+import { RoomStickyEventsEvent, type RoomStickyEventsMap } from "../models/room-sticky-events.ts";
 
 /**
  * Events emitted by MatrixRTCSession
@@ -124,14 +125,6 @@ export function slotDescriptionToId(slotDescription: SlotDescription): string {
 // - we use a `Ms` postfix if the option is a duration to avoid using words like:
 //   `time`, `duration`, `delay`, `timeout`... that might be mistaken/confused with technical terms.
 export interface MembershipConfig {
-    /**
-     * Use the new Manager.
-     *
-     * Default: `false`.
-     * @deprecated does nothing anymore we always default to the new membership manager.
-     */
-    useNewMembershipManager?: boolean;
-
     /**
      * The timeout (in milliseconds) after we joined the call, that our membership should expire
      * unless we have explicitly updated it.
@@ -193,7 +186,14 @@ export interface MembershipConfig {
      * but only applies to calls to the `_unstable_updateDelayedEvent` endpoint with a body of `{action:"restart"}`.)
      */
     delayedLeaveEventRestartLocalTimeoutMs?: number;
-    useRtcMemberFormat?: boolean;
+
+    /**
+     * Send membership using sticky events rather than state events.
+     * This also make the client use the new m.rtc.member MSC4354 event format. (instead of m.call.member)
+     *
+     * **WARNING**: This is an unstable feature and not all clients will support it.
+     */
+    unstableSendStickyEvents?: boolean;
 }
 
 export interface EncryptionConfig {
@@ -239,6 +239,19 @@ export interface EncryptionConfig {
 }
 export type JoinSessionConfig = SessionConfig & MembershipConfig & EncryptionConfig;
 
+interface SessionMembershipsForRoomOpts {
+    /**
+     * Listen for incoming sticky member events. If disabled, this session will
+     * ignore any incoming sticky events.
+     */
+    listenForStickyEvents: boolean;
+    /**
+     * Listen for incoming  member state events (legacy). If disabled, this session will
+     * ignore any incoming state events.
+     */
+    listenForMemberStateEvents: boolean;
+}
+
 /**
  * A MatrixRTCSession manages the membership & properties of a MatrixRTC session.
  * This class doesn't deal with media at all, just membership & properties of a session.
@@ -308,7 +321,10 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * @deprecated Use `MatrixRTCSession.sessionMembershipsForSlot` instead.
      */
     public static async callMembershipsForRoom(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById" | "client">,
+        room: Pick<
+            Room,
+            "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById" | "_unstable_getStickyEvents"
+        >,
         client: Pick<MatrixClient, "fetchRoomEvent">,
     ): Promise<CallMembership[]> {
         return await MatrixRTCSession.sessionMembershipsForSlot(room, client, {
@@ -321,7 +337,10 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * @deprecated use `MatrixRTCSession.slotMembershipsForRoom` instead.
      */
     public static async sessionMembershipsForRoom(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById" | "client">,
+        room: Pick<
+            Room,
+            "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById" | "_unstable_getStickyEvents"
+        >,
         client: Pick<MatrixClient, "fetchRoomEvent">,
         sessionDescription: SlotDescription,
     ): Promise<CallMembership[]> {
@@ -331,23 +350,61 @@ export class MatrixRTCSession extends TypedEventEmitter<
     /**
      * Returns all the call memberships for a room that match the provided `sessionDescription`,
      * oldest first.
+     *
+     * By default, this will return *both* sticky and member state events.
      */
     public static async sessionMembershipsForSlot(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById">,
+        room: Pick<
+            Room,
+            "getLiveTimeline" | "roomId" | "hasMembershipState" | "findEventById" | "_unstable_getStickyEvents"
+        >,
         client: Pick<MatrixClient, "fetchRoomEvent">,
         slotDescription: SlotDescription,
         existingMemberships?: CallMembership[],
+        { listenForStickyEvents, listenForMemberStateEvents }: SessionMembershipsForRoomOpts = {
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: true,
+        },
     ): Promise<CallMembership[]> {
         const logger = rootLogger.getChild(`[MatrixRTCSession ${room.roomId}]`);
+        let callMemberEvents = [] as MatrixEvent[];
+        if (listenForStickyEvents) {
+            // prefill with sticky events
+            callMemberEvents = [...room._unstable_getStickyEvents()].filter(
+                (e) => e.getType() === EventType.RTCMembership,
+            );
+        }
+        if (listenForMemberStateEvents) {
             const roomState = room.getLiveTimeline().getState(EventTimeline.FORWARDS);
             if (!roomState) {
                 logger.warn("Couldn't get state for room " + room.roomId);
                 throw new Error("Could't get state for room " + room.roomId);
             }
-        const callMemberEvents = roomState.getStateEvents(EventType.GroupCallMemberPrefix);
+            const callMemberStateEvents = roomState.getStateEvents(EventType.GroupCallMemberPrefix);
+            callMemberEvents = callMemberEvents.concat(
+                callMemberStateEvents.filter(
+                    (callMemberStateEvent) =>
+                        !callMemberEvents.some(
+                            // only care about state events which have keys which we have not yet seen in the sticky events.
+                            (stickyEvent) =>
+                                stickyEvent.getContent().msc4354_sticky_key === callMemberStateEvent.getStateKey(),
+                        ),
+                ),
+            );
+        }
         const callMemberships: CallMembership[] = [];
 
         const createMembership = async (memberEvent: MatrixEvent): Promise<CallMembership | undefined> => {
+            const content = memberEvent.getContent();
+
+            // Ignore sticky keys for the count
+            const eventKeysCount = Object.keys(content).filter((k) => k !== "msc4354_sticky_key").length;
+            // Dont even bother about empty events (saves us from costly type/"key in" checks in bigger rooms)
+            if (eventKeysCount === 0) return undefined;
+
+            // We first decide if its a MSC4143 event (per device state key)
+            if (!(eventKeysCount > 1 && "application" in content)) return undefined;
+
             const relatedEventId = memberEvent.relationEventId;
             const fetchRelatedEvent = async (): Promise<MatrixEvent | undefined> => {
                 const eventData = await client
@@ -415,11 +472,21 @@ export class MatrixRTCSession extends TypedEventEmitter<
      *
      * @deprecated Use `MatrixRTCSession.sessionForSlot` with sessionDescription `{ id: "", application: "m.call" }` instead.
      */
-    public static async roomSessionForRoom(client: MatrixClient, room: Room): Promise<MatrixRTCSession> {
+    public static async roomSessionForRoom(
-        const callMemberships = await MatrixRTCSession.sessionMembershipsForSlot(room, client, {
+        client: MatrixClient,
+        room: Room,
+        opts?: SessionMembershipsForRoomOpts,
+    ): Promise<MatrixRTCSession> {
+        const callMemberships = await MatrixRTCSession.sessionMembershipsForSlot(
+            room,
+            client,
+            {
                 id: "",
                 application: "m.call",
-        });
+            },
+            undefined,
+            opts,
+        );
         return new MatrixRTCSession(client, room, callMemberships, { id: "", application: "m.call" });
     }
 
@@ -443,8 +510,15 @@ export class MatrixRTCSession extends TypedEventEmitter<
         client: MatrixClient,
         room: Room,
         slotDescription: SlotDescription,
+        opts?: SessionMembershipsForRoomOpts,
     ): Promise<MatrixRTCSession> {
-        const callMemberships = await MatrixRTCSession.sessionMembershipsForSlot(room, client, slotDescription);
+        const callMemberships = await MatrixRTCSession.sessionMembershipsForSlot(
+            room,
+            client,
+            slotDescription,
+            undefined,
+            opts,
+        );
 
         return new MatrixRTCSession(client, room, callMemberships, slotDescription);
     }
@@ -478,10 +552,12 @@ export class MatrixRTCSession extends TypedEventEmitter<
             | "off"
             | "getUserId"
             | "getDeviceId"
+            | "sendEvent"
             | "sendStateEvent"
             | "_unstable_sendDelayedStateEvent"
             | "_unstable_updateDelayedEvent"
-            | "sendEvent"
+            | "_unstable_sendStickyEvent"
+            | "_unstable_sendStickyDelayedEvent"
             | "cancelPendingEvent"
             | "encryptAndSendToDevice"
             | "decryptEventIfNeeded"
@@ -489,7 +565,14 @@ export class MatrixRTCSession extends TypedEventEmitter<
         >,
         private roomSubset: Pick<
             Room,
-            "on" | "off" | "getLiveTimeline" | "roomId" | "getVersion" | "hasMembershipState" | "findEventById"
+            | "on"
+            | "off"
+            | "getLiveTimeline"
+            | "roomId"
+            | "getVersion"
+            | "hasMembershipState"
+            | "findEventById"
+            | "_unstable_getStickyEvents"
         >,
         public memberships: CallMembership[],
         /**
@@ -504,9 +587,10 @@ export class MatrixRTCSession extends TypedEventEmitter<
         const roomState = this.roomSubset.getLiveTimeline().getState(EventTimeline.FORWARDS);
         // TODO: double check if this is actually needed. Should be covered by refreshRoom in MatrixRTCSessionManager
         roomState?.on(RoomStateEvent.Members, this.onRoomMemberUpdate);
+        this.roomSubset.on(RoomStickyEventsEvent.Update, this.onStickyEventUpdate);
+
         this.setExpiryTimer();
     }
-
     /*
      * Returns true if we intend to be participating in the MatrixRTC session.
      * This is determined by checking if the relativeExpiry has been set.
@@ -526,7 +610,9 @@ export class MatrixRTCSession extends TypedEventEmitter<
         }
         const roomState = this.roomSubset.getLiveTimeline().getState(EventTimeline.FORWARDS);
         roomState?.off(RoomStateEvent.Members, this.onRoomMemberUpdate);
+        this.roomSubset.off(RoomStickyEventsEvent.Update, this.onStickyEventUpdate);
     }
+
     private reEmitter = new TypedReEmitter<
         MatrixRTCSessionEvent | RoomAndToDeviceEvents | MembershipManagerEvent,
         MatrixRTCSessionEventHandlerMap & RoomAndToDeviceEventsHandlerMap & MembershipManagerEventHandlerMap
@@ -556,14 +642,15 @@ export class MatrixRTCSession extends TypedEventEmitter<
             return;
         } else {
             // Create MembershipManager and pass the RTCSession logger (with room id info)
-
+            this.membershipManager = joinConfig?.unstableSendStickyEvents
-            this.membershipManager = new MembershipManager(
+                ? new StickyEventMembershipManager(
                       joinConfig,
                       this.roomSubset,
                       this.client,
                       this.slotDescription,
                       this.logger,
-            );
+                  )
+                : new MembershipManager(joinConfig, this.roomSubset, this.client, this.slotDescription, this.logger);
 
             this.reEmitter.reEmit(this.membershipManager!, [
                 MembershipManagerEvent.ProbablyLeft,
@@ -802,10 +889,27 @@ export class MatrixRTCSession extends TypedEventEmitter<
     /**
      * Call this when the Matrix room members have changed.
      */
-    public onRoomMemberUpdate = (): void => {
+    public readonly onRoomMemberUpdate = (): void => {
         void this.recalculateSessionMembers();
     };
 
+    /**
+     * Call this when a sticky event update has occured.
+     */
+    private readonly onStickyEventUpdate: RoomStickyEventsMap[RoomStickyEventsEvent.Update] = (
+        added,
+        updated,
+        removed,
+    ): void => {
+        if (
+            [...added, ...removed, ...updated.flatMap((v) => [v.current, v.previous])].some(
+                (e) => e.getType() === EventType.RTCMembership,
+            )
+        ) {
+            void this.recalculateSessionMembers();
+        }
+    };
+
     /**
      * Call this when something changed that may impacts the current MatrixRTC members in this session.
      */
@@ -861,6 +965,8 @@ export class MatrixRTCSession extends TypedEventEmitter<
             // If anyone else joins the session it is no longer our responsibility to send the notification.
             // (If we were the joiner we already did sent the notification in the block above.)
             if (this.memberships.length > 0) this.pendingNotificationToSend = undefined;
+        } else {
+            this.logger.debug(`No membership changes detected for room ${this.roomSubset.roomId}`);
         }
         // This also needs to be done if `changed` = false
         // A member might have updated their fingerprint (created_ts)

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -18,7 +18,7 @@ import { type Logger } from "../logger.ts";
 import { type MatrixClient, ClientEvent } from "../client.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
 import { type Room } from "../models/room.ts";
-import { type RoomState, RoomStateEvent } from "../models/room-state.ts";
+import { RoomStateEvent } from "../models/room-state.ts";
 import { type MatrixEvent } from "../models/event.ts";
 import { MatrixRTCSession, type SlotDescription } from "./MatrixRTCSession.ts";
 import { EventType } from "../@types/event.ts";
@@ -73,6 +73,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         }
 
         this.client.on(ClientEvent.Room, this.onRoom);
+        this.client.on(ClientEvent.Event, this.onEvent);
         this.client.on(RoomStateEvent.Events, this.onRoomState);
     }
 
@@ -83,6 +84,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         this.roomSessions.clear();
 
         this.client.off(ClientEvent.Room, this.onRoom);
+        this.client.off(ClientEvent.Event, this.onEvent);
         this.client.off(RoomStateEvent.Events, this.onRoomState);
     }
 
@@ -113,16 +115,28 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         void this.refreshRoom(room);
     };
 
-    private onRoomState = (event: MatrixEvent, _state: RoomState): void => {
+    private readonly onEvent = (event: MatrixEvent): void => {
+        if (!event.unstableStickyExpiresAt) return; // Not sticky, not interested.
+
+        if (event.getType() !== EventType.RTCMembership) return;
+
+        const room = this.client.getRoom(event.getRoomId());
+        if (!room) return;
+
+        void this.refreshRoom(room);
+    };
+
+    private readonly onRoomState = (event: MatrixEvent): void => {
+        if (event.getType() !== EventType.GroupCallMemberPrefix) {
+            return;
+        }
         const room = this.client.getRoom(event.getRoomId());
         if (!room) {
             this.logger.error(`Got room state event for unknown room ${event.getRoomId()}!`);
             return;
         }
 
-        if (event.getType() == EventType.GroupCallMemberPrefix) {
         void this.refreshRoom(room);
-        }
     };
 
     private async refreshRoom(room: Room): Promise<void> {

src/matrixrtc/MembershipManager.ts

@@ -16,7 +16,12 @@ limitations under the License.
 import { AbortError } from "p-retry";
 
 import { EventType, RelationType } from "../@types/event.ts";
-import { UpdateDelayedEventAction } from "../@types/requests.ts";
+import {
+    type ISendEventResponse,
+    type SendDelayedEventResponse,
+    UpdateDelayedEventAction,
+} from "../@types/requests.ts";
+import { type EmptyObject } from "../@types/common.ts";
 import type { MatrixClient } from "../client.ts";
 import { ConnectionError, HTTPError, MatrixError } from "../http-api/errors.ts";
 import { type Logger, logger as rootLogger } from "../logger.ts";
@@ -85,6 +90,12 @@ On Leave: ─────────  STOP ALL ABOVE
 (s) Successful restart/resend
 */
 
+/**
+ * Call membership should always remain sticky for this amount
+ * of time.
+ */
+const MEMBERSHIP_STICKY_DURATION_MS = 60 * 60 * 1000; // 60 minutes
+
 /**
  * The different types of actions the MembershipManager can take.
  * @internal
@@ -145,6 +156,23 @@ export interface MembershipManagerState {
     probablyLeft: boolean;
 }
 
+function createInsertActionUpdate(type: MembershipActionType, offset?: number): ActionUpdate {
+    return {
+        insert: [{ ts: Date.now() + (offset ?? 0), type }],
+    };
+}
+
+function createReplaceActionUpdate(type: MembershipActionType, offset?: number): ActionUpdate {
+    return {
+        replace: [{ ts: Date.now() + (offset ?? 0), type }],
+    };
+}
+
+type MembershipManagerClient = Pick<
+    MatrixClient,
+    "getUserId" | "getDeviceId" | "sendStateEvent" | "_unstable_sendDelayedStateEvent" | "_unstable_updateDelayedEvent"
+>;
+
 /**
  * This class is responsible for sending all events relating to the own membership of a matrixRTC call.
  * It has the following tasks:
@@ -163,8 +191,8 @@ export class MembershipManager
     implements IMembershipManager
 {
     private activated = false;
-    private logger: Logger;
+    private readonly logger: Logger;
-    private callIntent: RTCCallIntent | undefined;
+    protected callIntent: RTCCallIntent | undefined;
 
     public isActivated(): boolean {
         return this.activated;
@@ -296,16 +324,9 @@ export class MembershipManager
      * @param client
      */
     public constructor(
-        private joinConfig: (SessionConfig & MembershipConfig) | undefined,
+        private readonly joinConfig: (SessionConfig & MembershipConfig) | undefined,
-        private room: Pick<Room, "getLiveTimeline" | "roomId" | "getVersion">,
+        protected readonly room: Pick<Room, "roomId" | "getVersion">,
-        private client: Pick<
+        protected readonly client: MembershipManagerClient,
-            MatrixClient,
-            | "getUserId"
-            | "getDeviceId"
-            | "sendStateEvent"
-            | "_unstable_sendDelayedStateEvent"
-            | "_unstable_updateDelayedEvent"
-        >,
         public readonly slotDescription: SlotDescription,
         parentLogger?: Logger,
     ) {
@@ -362,11 +383,11 @@ export class MembershipManager
         };
     }
     // Membership Event static parameters:
-    private deviceId: string;
+    protected deviceId: string;
-    private memberId: string;
+    protected memberId: string;
+    protected rtcTransport?: Transport;
     /** @deprecated This will be removed in favor or rtcTransport becoming a list of actively used transports */
     private fociPreferred?: Transport[];
-    private rtcTransport?: Transport;
 
     // Config:
     private delayedLeaveEventDelayMsOverride?: number;
@@ -381,9 +402,13 @@ export class MembershipManager
         return this.joinConfig?.membershipEventExpiryHeadroomMs ?? 5_000;
     }
     private computeNextExpiryActionTs(iteration: number): number {
-        return this.state.startTime + this.membershipEventExpiryMs * iteration - this.membershipEventExpiryHeadroomMs;
+        return (
+            this.state.startTime +
+            Math.min(this.membershipEventExpiryMs, MEMBERSHIP_STICKY_DURATION_MS) * iteration -
+            this.membershipEventExpiryHeadroomMs
+        );
     }
-    private get delayedLeaveEventDelayMs(): number {
+    protected get delayedLeaveEventDelayMs(): number {
         return this.delayedLeaveEventDelayMsOverride ?? this.joinConfig?.delayedLeaveEventDelayMs ?? 8_000;
     }
     private get delayedLeaveEventRestartMs(): number {
@@ -395,13 +420,10 @@ export class MembershipManager
     private get maximumNetworkErrorRetryCount(): number {
         return this.joinConfig?.maximumNetworkErrorRetryCount ?? 10;
     }
-
     private get delayedLeaveEventRestartLocalTimeoutMs(): number {
         return this.joinConfig?.delayedLeaveEventRestartLocalTimeoutMs ?? 2000;
     }
-    private get useRtcMemberFormat(): boolean {
+
-        return this.joinConfig?.useRtcMemberFormat ?? false;
-    }
     // LOOP HANDLER:
     private membershipLoopHandler(type: MembershipActionType): Promise<ActionUpdate> {
         switch (type) {
@@ -456,22 +478,23 @@ export class MembershipManager
         }
     }
 
+    // an abstraction to switch between sending state or a sticky event
+    protected clientSendDelayedDisconnectMembership: () => Promise<SendDelayedEventResponse> = () =>
+        this.client._unstable_sendDelayedStateEvent(
+            this.room.roomId,
+            { delay: this.delayedLeaveEventDelayMs },
+            EventType.GroupCallMemberPrefix,
+            {},
+            this.memberId,
+        );
+
     // HANDLERS (used in the membershipLoopHandler)
     private sendOrResendDelayedLeaveEvent(): Promise<ActionUpdate> {
         // We can reach this at the start of a call (where we do not yet have a membership: state.hasMemberStateEvent=false)
         // or during a call if the state event canceled our delayed event or caused by an unexpected error that removed our delayed event.
         // (Another client could have canceled it, the homeserver might have removed/lost it due to a restart, ...)
         // In the `then` and `catch` block we treat both cases differently. "if (this.state.hasMemberStateEvent) {} else {}"
-        return this.client
+        return this.clientSendDelayedDisconnectMembership()
-            ._unstable_sendDelayedStateEvent(
-                this.room.roomId,
-                {
-                    delay: this.delayedLeaveEventDelayMs,
-                },
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                {}, // leave event
-                this.memberId,
-            )
             .then((response) => {
                 this.state.expectedServerDelayLeaveTs = Date.now() + this.delayedLeaveEventDelayMs;
                 this.setAndEmitProbablyLeft(false);
@@ -495,7 +518,7 @@ export class MembershipManager
                 if (this.manageMaxDelayExceededSituation(e)) {
                     return createInsertActionUpdate(repeatActionType);
                 }
-                const update = this.actionUpdateFromErrors(e, repeatActionType, "sendDelayedStateEvent");
+                const update = this.actionUpdateFromErrors(e, repeatActionType, "_unstable_sendDelayedStateEvent");
                 if (update) return update;
 
                 if (this.state.hasMemberStateEvent) {
@@ -651,14 +674,19 @@ export class MembershipManager
             });
     }
 
-    private sendJoinEvent(): Promise<ActionUpdate> {
+    protected clientSendMembership: (
-        return this.client
+        myMembership: RtcMembershipData | SessionMembershipData | EmptyObject,
-            .sendStateEvent(
+    ) => Promise<ISendEventResponse> = (myMembership) => {
+        return this.client.sendStateEvent(
             this.room.roomId,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
+            EventType.GroupCallMemberPrefix,
-                this.makeMyMembership(this.membershipEventExpiryMs),
+            myMembership as EmptyObject | SessionMembershipData,
             this.memberId,
-            )
+        );
+    };
+
+    private async sendJoinEvent(): Promise<ActionUpdate> {
+        return this.clientSendMembership(this.makeMyMembership(this.membershipEventExpiryMs))
             .then(() => {
                 this.setAndEmitProbablyLeft(false);
                 this.state.startTime = Date.now();
@@ -698,12 +726,8 @@ export class MembershipManager
 
     private updateExpiryOnJoinedEvent(): Promise<ActionUpdate> {
         const nextExpireUpdateIteration = this.state.expireUpdateIterations + 1;
-        return this.client
+        return this.clientSendMembership(
-            .sendStateEvent(
-                this.room.roomId,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
             this.makeMyMembership(this.membershipEventExpiryMs * nextExpireUpdateIteration),
-                this.memberId,
         )
             .then(() => {
                 // Success, we reset retries and schedule update.
@@ -725,14 +749,8 @@ export class MembershipManager
                 throw e;
             });
     }
-    private sendFallbackLeaveEvent(): Promise<ActionUpdate> {
+    private async sendFallbackLeaveEvent(): Promise<ActionUpdate> {
-        return this.client
+        return this.clientSendMembership({})
-            .sendStateEvent(
-                this.room.roomId,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                {},
-                this.memberId,
-            )
             .then(() => {
                 this.resetRateLimitCounter(MembershipActionType.SendLeaveEvent);
                 this.state.hasMemberStateEvent = false;
@@ -758,25 +776,9 @@ export class MembershipManager
     /**
      * Constructs our own membership
      */
-    private makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
+    protected makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
         const ownMembership = this.ownMembership;
-        if (this.useRtcMemberFormat) {
+
-            const relationObject = ownMembership?.eventId
-                ? { "m.relation": { rel_type: RelationType.Reference, event_id: ownMembership?.eventId } }
-                : {};
-            return {
-                application: {
-                    type: this.slotDescription.application,
-                    ...(this.callIntent ? { "m.call.intent": this.callIntent } : {}),
-                },
-                slot_id: slotDescriptionToId(this.slotDescription),
-                rtc_transports: this.rtcTransport ? [this.rtcTransport] : [],
-                member: { device_id: this.deviceId, user_id: this.client.getUserId()!, id: this.memberId },
-                versions: [],
-                ...relationObject,
-                [UNSTABLE_STICKY_KEY.name]: this.memberId,
-            };
-        } else {
         const focusObjects =
             this.rtcTransport === undefined
                 ? {
@@ -798,7 +800,6 @@ export class MembershipManager
             ...(ownMembership !== undefined ? { created_ts: ownMembership.createdTs() } : undefined),
         };
     }
-    }
 
     // Error checks and handlers
 
@@ -832,7 +833,7 @@ export class MembershipManager
         return false;
     }
 
-    private actionUpdateFromErrors(
+    protected actionUpdateFromErrors(
         error: unknown,
         type: MembershipActionType,
         method: string,
@@ -880,7 +881,7 @@ export class MembershipManager
             return createInsertActionUpdate(type, resendDelay);
         }
 
-        throw Error("Exceeded maximum retries for " + type + " attempts (client." + method + "): " + (error as Error));
+        throw Error("Exceeded maximum retries for " + type + " attempts (client." + method + ")", { cause: error });
     }
 
     /**
@@ -1024,14 +1025,69 @@ export class MembershipManager
     }
 }
 
-function createInsertActionUpdate(type: MembershipActionType, offset?: number): ActionUpdate {
+/**
-    return {
+ * Implementation of the Membership manager that uses sticky events
-        insert: [{ ts: Date.now() + (offset ?? 0), type }],
+ * rather than state events.
-    };
+ */
-}
+export class StickyEventMembershipManager extends MembershipManager {
+    public constructor(
+        joinConfig: (SessionConfig & MembershipConfig) | undefined,
+        room: Pick<Room, "getLiveTimeline" | "roomId" | "getVersion">,
+        private readonly clientWithSticky: MembershipManagerClient &
+            Pick<MatrixClient, "_unstable_sendStickyEvent" | "_unstable_sendStickyDelayedEvent">,
+        sessionDescription: SlotDescription,
+        parentLogger?: Logger,
+    ) {
+        super(joinConfig, room, clientWithSticky, sessionDescription, parentLogger);
+    }
 
-function createReplaceActionUpdate(type: MembershipActionType, offset?: number): ActionUpdate {
+    protected clientSendDelayedDisconnectMembership: () => Promise<SendDelayedEventResponse> = () =>
-    return {
+        this.clientWithSticky._unstable_sendStickyDelayedEvent(
-        replace: [{ ts: Date.now() + (offset ?? 0), type }],
+            this.room.roomId,
+            MEMBERSHIP_STICKY_DURATION_MS,
+            { delay: this.delayedLeaveEventDelayMs },
+            null,
+            EventType.RTCMembership,
+            { msc4354_sticky_key: this.memberId },
+        );
+
+    protected clientSendMembership: (
+        myMembership: RtcMembershipData | SessionMembershipData | EmptyObject,
+    ) => Promise<ISendEventResponse> = (myMembership) => {
+        return this.clientWithSticky._unstable_sendStickyEvent(
+            this.room.roomId,
+            MEMBERSHIP_STICKY_DURATION_MS,
+            null,
+            EventType.RTCMembership,
+            { ...myMembership, msc4354_sticky_key: this.memberId },
+        );
     };
+
+    private static nameMap = new Map([
+        ["sendStateEvent", "_unstable_sendStickyEvent"],
+        ["sendDelayedStateEvent", "_unstable_sendStickyDelayedEvent"],
+    ]);
+    protected actionUpdateFromErrors(e: unknown, t: MembershipActionType, m: string): ActionUpdate | undefined {
+        return super.actionUpdateFromErrors(e, t, StickyEventMembershipManager.nameMap.get(m) ?? "unknown");
+    }
+
+    protected makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
+        const ownMembership = this.ownMembership;
+
+        const relationObject = ownMembership?.eventId
+            ? { "m.relation": { rel_type: RelationType.Reference, event_id: ownMembership?.eventId } }
+            : {};
+        return {
+            application: {
+                type: this.slotDescription.application,
+                ...(this.callIntent ? { "m.call.intent": this.callIntent } : {}),
+            },
+            slot_id: slotDescriptionToId(this.slotDescription),
+            rtc_transports: this.rtcTransport ? [this.rtcTransport] : [],
+            member: { device_id: this.deviceId, user_id: this.client.getUserId()!, id: this.memberId },
+            versions: [],
+            ...relationObject,
+            [UNSTABLE_STICKY_KEY.name]: this.memberId,
+        };
+    }
 }

src/matrixrtc/types.ts

@@ -13,7 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-import type { IMentions } from "../matrix.ts";
+import type { IContent, IMentions } from "../matrix.ts";
 import type { RelationEvent } from "../types.ts";
 import type { CallMembership } from "./CallMembership.ts";
 
@@ -102,9 +102,45 @@ export type RTCNotificationType = "ring" | "notification";
  * May be any string, although `"audio"` and `"video"` are commonly accepted values.
  */
 export type RTCCallIntent = "audio" | "video" | string;
+
+/**
+ * This will check if the content has all the expected fields to be a valid IRTCNotificationContent.
+ * It will also cap the lifetime to 90000ms (1.5 min) if a higher value is provided.
+ * @param content
+ * @throws if the content is invalid
+ * @returns a parsed IRTCNotificationContent
+ */
+export function parseCallNotificationContent(content: IContent): IRTCNotificationContent {
+    if (content["m.mentions"] && typeof content["m.mentions"] !== "object") {
+        throw new Error("malformed m.mentions");
+    }
+    if (typeof content["notification_type"] !== "string") {
+        throw new Error("Missing or invalid notification_type");
+    }
+    if (typeof content["sender_ts"] !== "number") {
+        throw new Error("Missing or invalid sender_ts");
+    }
+    if (typeof content["lifetime"] !== "number") {
+        throw new Error("Missing or invalid lifetime");
+    }
+
+    if (content["relation"] && content["relation"]["rel_type"] !== "m.reference") {
+        throw new Error("Invalid relation");
+    }
+    if (content["m.call.intent"] && typeof content["m.call.intent"] !== "string") {
+        throw new Error("Invalid m.call.intent");
+    }
+
+    const cappedLifetime = content["lifetime"] >= 90000 ? 90000 : content["lifetime"];
+    return { ...content, lifetime: cappedLifetime } as IRTCNotificationContent;
+}
+
+/**
+ * Interface for `org.matrix.msc4075.rtc.notification` events.
+ * Don't cast event content to this directly. Use `parseCallNotificationContent` instead to validate the content first.
+ */
 export interface IRTCNotificationContent extends RelationEvent {
-    "m.mentions": IMentions;
+    "m.mentions"?: IMentions;
-    "decline_reason"?: string;
     "notification_type": RTCNotificationType;
     /**
      * The initial intent of the calling user.

src/models/room-sticky-events.ts

@@ -32,7 +32,7 @@ export enum RoomStickyEventsEvent {
     Update = "RoomStickyEvents.Update",
 }
 
-type StickyMatrixEvent = MatrixEvent & { unstableStickyExpiresAt: number };
+export type StickyMatrixEvent = MatrixEvent & { unstableStickyExpiresAt: number };
 
 export type RoomStickyEventsMap = {
     /**
@@ -48,17 +48,64 @@ export type RoomStickyEventsMap = {
     ) => void;
 };
 
+type UserId = `@${string}`;
+
+function assertIsUserId(value: unknown): asserts value is UserId {
+    if (typeof value !== "string") throw new Error("Not a string");
+    if (!value.startsWith("@")) throw new Error("Not a userId");
+}
+
 /**
  * Tracks sticky events on behalf of one room, and fires an event
  * whenever a sticky event is updated or replaced.
  */
 export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEvent, RoomStickyEventsMap> {
-    private readonly stickyEventsMap = new Map<string, Map<string, StickyMatrixEvent>>(); // (type -> stickyKey+userId) -> event
+    /**
+     * Sticky event map is a nested map of:
+     *  eventType -> `content.sticky_key sender` -> StickyMatrixEvent[]
+     *
+     * The events are ordered in latest to earliest expiry, so that the first event
+     * in the array will always be the "current" one.
+     */
+    private readonly stickyEventsMap = new Map<string, Map<string, StickyMatrixEvent[]>>();
+    /**
+     * These are sticky events that have no sticky key and therefore exist outside the tuple
+     * system above. They are just held in this Set until they expire.
+     */
     private readonly unkeyedStickyEvents = new Set<StickyMatrixEvent>();
 
     private stickyEventTimer?: ReturnType<typeof setTimeout>;
     private nextStickyEventExpiryTs: number = Number.MAX_SAFE_INTEGER;
 
+    /**
+     * Sort two sticky events by order of expiry. This assumes the sticky events have the same
+     * `type`, `sticky_key` and `sender`.
+     * @returns A positive value if event A will expire sooner, or a negative value if event B will expire sooner.
+     */
+    private static sortStickyEvent(eventA: StickyMatrixEvent, eventB: StickyMatrixEvent): number {
+        // Sticky events with the same key have to use the same expiration duration.
+        // Hence, comparing via `origin_server_ts` yields the exact same result as comparing their expiration time.
+        if (eventB.getTs() !== eventA.getTs()) {
+            return eventB.getTs() - eventA.getTs();
+        }
+
+        if ((eventB.getId() ?? "") > (eventA.getId() ?? "")) {
+            return 1;
+        }
+
+        // This should fail as we've got corruption in our sticky array.
+        throw Error("Comparing two sticky events with the same event ID is not allowed.");
+    }
+
+    /**
+     * Generate the correct key for an event to be found in the inner maps of `stickyEventsMap`.
+     * @param stickyKey The sticky key of an event.
+     * @param sender The sender of the event.
+     */
+    private static stickyMapKey(stickyKey: string, sender: UserId): string {
+        return `${stickyKey}${sender}`;
+    }
+
     /**
      * Get all sticky events that are currently active.
      * @returns An iterable set of events.
@@ -66,7 +113,11 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
     public *getStickyEvents(): Iterable<StickyMatrixEvent> {
         yield* this.unkeyedStickyEvents;
         for (const innerMap of this.stickyEventsMap.values()) {
-            yield* innerMap.values();
+            // Inner map contains a map of sender+stickykeys => all sticky events
+            for (const events of innerMap.values()) {
+                // The first sticky event is the "current" one in the sticky map.
+                yield events[0];
+            }
         }
     }
 
@@ -78,7 +129,8 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
      * @returns A matching active sticky event, or undefined.
      */
     public getKeyedStickyEvent(sender: string, type: string, stickyKey: string): StickyMatrixEvent | undefined {
-        return this.stickyEventsMap.get(type)?.get(`${stickyKey}${sender}`);
+        assertIsUserId(sender);
+        return this.stickyEventsMap.get(type)?.get(RoomStickyEventsStore.stickyMapKey(stickyKey, sender))?.[0];
     }
 
     /**
@@ -113,9 +165,8 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         }
         const sender = event.getSender();
         const type = event.getType();
-        if (!sender) {
+        assertIsUserId(sender);
-            throw new Error(`${event.getId()} is missing a sender`);
+        if (event.unstableStickyExpiresAt <= Date.now()) {
-        } else if (event.unstableStickyExpiresAt <= Date.now()) {
             logger.info("ignored sticky event with older expiration time than current time", stickyKey);
             return { added: false };
         }
@@ -126,42 +177,39 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
             throw new Error("Expected sender to start with @");
         }
 
-        let prevEvent: StickyMatrixEvent | undefined;
+        const stickyEvent = event as StickyMatrixEvent;
-        if (stickyKey !== undefined) {
-            // Why this is safe:
-            // A type may contain anything but the *sender* is tightly
-            // constrained so that a key will always end with a @<user_id>
-            // E.g. Where a malicous event type might be "rtc.member.event@foo:bar" the key becomes:
-            // "rtc.member.event.@foo:bar@bar:baz"
-            const innerMapKey = `${stickyKey}${sender}`;
-            prevEvent = this.stickyEventsMap.get(type)?.get(innerMapKey);
-
-            // sticky events are not allowed to expire sooner than their predecessor.
-            if (prevEvent && event.unstableStickyExpiresAt < prevEvent.unstableStickyExpiresAt) {
-                logger.info("ignored sticky event with older expiry time", stickyKey);
-                return { added: false };
-            } else if (
-                prevEvent &&
-                event.getTs() === prevEvent.getTs() &&
-                (event.getId() ?? "") < (prevEvent.getId() ?? "")
-            ) {
-                // This path is unlikely, as it requires both events to have the same TS.
-                logger.info("ignored sticky event due to 'id tie break rule' on sticky_key", stickyKey);
-                return { added: false };
-            }
-            if (!this.stickyEventsMap.has(type)) {
-                this.stickyEventsMap.set(type, new Map());
-            }
-            this.stickyEventsMap.get(type)!.set(innerMapKey, event as StickyMatrixEvent);
-        } else {
-            this.unkeyedStickyEvents.add(event as StickyMatrixEvent);
-        }
 
+        if (stickyKey === undefined) {
+            this.unkeyedStickyEvents.add(stickyEvent);
             // Recalculate the next expiry time.
             this.nextStickyEventExpiryTs = Math.min(event.unstableStickyExpiresAt, this.nextStickyEventExpiryTs);
 
             this.scheduleStickyTimer();
-        return { added: true, prevEvent };
+            return { added: true };
+        }
+
+        // Why this is safe:
+        // A type may contain anything but the *sender* is tightly
+        // constrained so that a key will always end with a @<user_id>
+        // E.g. Where a malicious event type might be "rtc.member.event@foo:bar" the key becomes:
+        // "rtc.member.event.@foo:bar@bar:baz"
+        const innerMapKey = RoomStickyEventsStore.stickyMapKey(stickyKey, sender);
+        const currentEventSet = [stickyEvent, ...(this.stickyEventsMap.get(type)?.get(innerMapKey) ?? [])].sort(
+            RoomStickyEventsStore.sortStickyEvent,
+        );
+        if (!this.stickyEventsMap.has(type)) {
+            this.stickyEventsMap.set(type, new Map());
+        }
+        this.stickyEventsMap.get(type)?.set(innerMapKey, currentEventSet);
+
+        // Recalculate the next expiry time.
+        this.nextStickyEventExpiryTs = Math.min(stickyEvent.unstableStickyExpiresAt, this.nextStickyEventExpiryTs);
+
+        this.scheduleStickyTimer();
+        return {
+            added: currentEventSet[0] === stickyEvent,
+            prevEvent: currentEventSet?.[1],
+        };
     }
 
     /**
@@ -217,17 +265,24 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         // We will recalculate this as we check all events.
         this.nextStickyEventExpiryTs = Number.MAX_SAFE_INTEGER;
         for (const [eventType, innerEvents] of this.stickyEventsMap.entries()) {
-            for (const [innerMapKey, event] of innerEvents) {
+            for (const [innerMapKey, [currentEvent, ...previousEvents]] of innerEvents) {
                 // we only added items with `sticky` into this map so we can assert non-null here
-                if (now >= event.unstableStickyExpiresAt) {
+                if (now >= currentEvent.unstableStickyExpiresAt) {
-                    logger.debug("Expiring sticky event", event.getId());
+                    logger.debug("Expiring sticky event", currentEvent.getId());
-                    removedEvents.push(event);
+                    removedEvents.push(currentEvent);
                     this.stickyEventsMap.get(eventType)!.delete(innerMapKey);
                 } else {
+                    // Ensure we remove any previous events which have now expired, to avoid unbounded memory consumption.
+                    this.stickyEventsMap
+                        .get(eventType)!
+                        .set(innerMapKey, [
+                            currentEvent,
+                            ...previousEvents.filter((e) => e.unstableStickyExpiresAt <= now),
+                        ]);
                     // If not removing the event, check to see if it's the next lowest expiry.
                     this.nextStickyEventExpiryTs = Math.min(
                         this.nextStickyEventExpiryTs,
-                        event.unstableStickyExpiresAt,
+                        currentEvent.unstableStickyExpiresAt,
                     );
                 }
             }
@@ -253,6 +308,93 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         this.scheduleStickyTimer();
     };
 
+    /**
+     * Handles incoming event redactions. Checks the sticky map
+     * for any active sticky events being redacted.
+     * @param redactedEvent The MatrixEvent OR event ID of the event being redacted. MAY not be a sticky event.
+     */
+    public handleRedaction(redactedEvent: MatrixEvent | string): void {
+        // Note, we do not adjust`nextStickyEventExpiryTs` here.
+        // If this event happens to be the most recent expiring event
+        // then we may do one extra iteration of cleanExpiredStickyEvents
+        // but this saves us having to iterate over all events here to calculate
+        // the next expiry time.
+
+        // Note, as soon as we find a positive match on an event in this function
+        // we can return. There is no need to continue iterating on a positive match
+        // as an event can only appear in one map.
+
+        // Handle unkeyedStickyEvents first since it's *quick*.
+        const redactEventId = typeof redactedEvent === "string" ? redactedEvent : redactedEvent.getId();
+        for (const event of this.unkeyedStickyEvents) {
+            if (event.getId() === redactEventId) {
+                this.unkeyedStickyEvents.delete(event);
+                this.emit(RoomStickyEventsEvent.Update, [], [], [event]);
+                return;
+            }
+        }
+
+        // Faster method of finding the event since we have the event cached.
+        if (typeof redactedEvent !== "string" && !redactedEvent.isRedacted()) {
+            const stickyKey = redactedEvent.getContent().msc4354_sticky_key;
+            if (typeof stickyKey !== "string" && stickyKey !== undefined) {
+                return; // Not a sticky event.
+            }
+            const eventType = redactedEvent.getType();
+            const sender = redactedEvent.getSender();
+            assertIsUserId(sender);
+            const innerMap = this.stickyEventsMap.get(eventType);
+            if (!innerMap) {
+                return;
+            }
+            const mapKey = RoomStickyEventsStore.stickyMapKey(stickyKey, sender);
+            const [currentEvent, ...previousEvents] = innerMap.get(mapKey) ?? [];
+            if (!currentEvent) {
+                // No event current in the map so ignore.
+                return;
+            }
+            logger.debug(`Redaction for ${redactEventId} under sticky key ${stickyKey}`);
+            // Revert to previous state, taking care to skip any other redacted events.
+            const newEvents = previousEvents.filter((e) => !e.isRedacted()).sort(RoomStickyEventsStore.sortStickyEvent);
+            this.stickyEventsMap.get(eventType)?.set(mapKey, newEvents);
+            if (newEvents.length) {
+                this.emit(
+                    RoomStickyEventsEvent.Update,
+                    [],
+                    [
+                        {
+                            // This looks confusing. This emits that the newer event
+                            // has been redacted and the previous event has taken it's place.
+                            previous: currentEvent,
+                            current: newEvents[0],
+                        },
+                    ],
+                    [],
+                );
+            } else {
+                // We did not find a previous event, so just expire.
+                innerMap.delete(mapKey);
+                if (innerMap.size === 0) {
+                    this.stickyEventsMap.delete(eventType);
+                }
+                this.emit(RoomStickyEventsEvent.Update, [], [], [currentEvent]);
+            }
+            return;
+        }
+
+        // We only know the event ID of the redacted event, so we need to
+        // traverse the map to find our event.
+        for (const innerMap of this.stickyEventsMap.values()) {
+            for (const [currentEvent] of innerMap.values()) {
+                if (currentEvent.getId() !== redactEventId) {
+                    continue;
+                }
+                // Found the event.
+                return this.handleRedaction(currentEvent);
+            }
+        }
+    }
+
     /**
      * Clear all events and stop the timer from firing.
      */

src/models/room.ts

@@ -2633,6 +2633,14 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
 
             // if we know about this event, redact its contents now.
             const redactedEvent = redactId ? this.findEventById(redactId) : undefined;
+            if (redactId) {
+                try {
+                    this.stickyEvents.handleRedaction(redactedEvent || redactId);
+                } catch (ex) {
+                    // Non-critical failure, but we should warn.
+                    logger.error("Failed to handle redaction for sticky event", ex);
+                }
+            }
             if (redactedEvent) {
                 this.applyEventAsRedaction(event, redactedEvent);
             }

src/rust-crypto/rust-crypto.ts

@@ -65,6 +65,7 @@ import {
     type KeyBackupRestoreOpts,
     type KeyBackupRestoreResult,
     type OwnDeviceKeys,
+    type SecretStorageStatus,
     type StartDehydrationOpts,
     UserVerificationStatus,
     type VerificationRequest,
@@ -78,7 +79,7 @@ import {
     type ServerSideSecretStorage,
 } from "../secret-storage.ts";
 import { CrossSigningIdentity } from "./CrossSigningIdentity.ts";
-import { secretStorageCanAccessSecrets, secretStorageContainsCrossSigningKeys } from "./secret-storage.ts";
+import { secretStorageContainsCrossSigningKeys } from "./secret-storage.ts";
 import { isVerificationEvent, RustVerificationRequest, verificationMethodIdentifierToMethod } from "./verification.ts";
 import { EventType, MsgType } from "../@types/event.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
@@ -827,6 +828,13 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      * Implementation of {@link CryptoApi#isSecretStorageReady}
      */
     public async isSecretStorageReady(): Promise<boolean> {
+        return (await this.getSecretStorageStatus()).ready;
+    }
+
+    /**
+     * Implementation of {@link CryptoApi#getSecretStorageStatus}
+     */
+    public async getSecretStorageStatus(): Promise<SecretStorageStatus> {
         // make sure that the cross-signing keys are stored
         const secretsToCheck: SecretStorageKey[] = [
             "m.cross_signing.master",
@@ -834,13 +842,32 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             "m.cross_signing.self_signing",
         ];
 
-        // if key backup is active, we also need to check that the backup decryption key is stored
+        // If key backup is active, we also need to check that the backup decryption key is stored
         const keyBackupEnabled = (await this.backupManager.getActiveBackupVersion()) != null;
         if (keyBackupEnabled) {
             secretsToCheck.push("m.megolm_backup.v1");
         }
 
-        return secretStorageCanAccessSecrets(this.secretStorage, secretsToCheck);
+        const defaultKeyId = await this.secretStorage.getDefaultKeyId();
+
+        const result: SecretStorageStatus = {
+            // Assume we have all secrets until proven otherwise
+            ready: true,
+            defaultKeyId,
+            secretStorageKeyValidityMap: {},
+        };
+
+        for (const secretName of secretsToCheck) {
+            // Check which keys this particular secret is encrypted with
+            const record = (await this.secretStorage.isStored(secretName)) || {};
+
+            // If it's encrypted with the right key, it is valid
+            const secretStored = !!defaultKeyId && defaultKeyId in record;
+            result.secretStorageKeyValidityMap[secretName] = secretStored;
+            result.ready = result.ready && secretStored;
+        }
+
+        return result;
     }
 
     /**