v39.1.1

* matrixRTC: Disable room transport fallback for keys

* post rebase fix

* post merge fix

---------

Co-authored-by: Will Hunt <will@half-shot.uk>

.github/actions/sign-release-tarball/action.yml

@@ -22,7 +22,7 @@ runs:
 
         - name: Upload tarball signature
           if: ${{ inputs.upload-url }}
-          uses: shogo82148/actions-upload-release-asset@e6cd4579c50a5d0eb50ca05d0d597daafca8cebb # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ env.VERSION }}.tar.gz.asc

.github/actions/upload-release-assets/action.yml

@@ -29,13 +29,13 @@ runs:
 
         - name: Upload asset signatures
           if: inputs.gpg-fingerprint
-          uses: shogo82148/actions-upload-release-asset@e6cd4579c50a5d0eb50ca05d0d597daafca8cebb # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ inputs.asset-path }}.asc
 
         - name: Upload assets
-          uses: shogo82148/actions-upload-release-asset@e6cd4579c50a5d0eb50ca05d0d597daafca8cebb # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
           with:
               upload_url: ${{ inputs.upload-url }}
               asset_path: ${{ inputs.asset-path }}

.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/pull_request.yaml

@@ -35,7 +35,7 @@ jobs:
             pull-requests: read
         steps:
             - name: Add notice
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               if: contains(github.event.pull_request.labels.*.name, 'X-Blocked')
               with:
                   script: |
@@ -49,7 +49,7 @@ jobs:
             pull-requests: write
         steps:
             - name: Check membership
-              if: github.event.pull_request.user.login != 'renovate[bot]'
+              if: github.event.pull_request.user.login != 'renovate[bot]' && github.event.pull_request.user.login != 'dependabot[bot]'
               uses: tspascoal/get-user-teams-membership@57e9f42acd78f4d0f496b3be4368fc5f62696662 # v3
               id: teams
               with:
@@ -60,7 +60,7 @@ jobs:
 
             - name: Add label
               if: steps.teams.outputs.isTeamMember == 'false'
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               with:
                   script: |
                       github.rest.issues.addLabels({
@@ -79,7 +79,7 @@ jobs:
             github.event.pull_request.head.repo.full_name != github.repository
         steps:
             - name: Close pull request
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               with:
                   script: |
                       github.rest.issues.createComment({

.github/workflows/release-checks.yml

@@ -18,7 +18,7 @@ jobs:
         runs-on: ubuntu-24.04
         steps:
             - name: Check for X-Release-Blocker label on any open issues or PRs
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               env:
                   REPO: ${{ inputs.repository }}
               with:

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

@@ -21,7 +21,7 @@ jobs:
                   ref: staging
                   fetch-depth: 0
 
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   node-version-file: package.json
                   cache: "yarn"
@@ -48,7 +48,7 @@ jobs:
 
             - name: Ingest upstream changes
               if: inputs.include-changes
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               env:
                   GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                   RELEASE_ID: ${{ steps.draft-release.outputs.id }}

.github/workflows/release-gitflow.yml

@@ -33,7 +33,7 @@ jobs:
                   sparse-checkout: |
                       scripts/release
 
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/release-make.yml

@@ -106,7 +106,7 @@ jobs:
               run: echo "VERSION=$(echo $VERSION | cut -d- -f1)" >> $GITHUB_ENV
 
             - name: Check version number not in use
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               with:
                   script: |
                       const { VERSION } = process.env;
@@ -125,7 +125,7 @@ jobs:
                   git config --global user.email "releases@riot.im"
                   git config --global user.name "RiotRobot"
 
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -218,7 +218,7 @@ jobs:
 
             - name: Validate release has expected assets
               if: inputs.expected-asset-count
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               env:
                   RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                   EXPECTED_ASSET_COUNT: ${{ inputs.expected-asset-count }}
@@ -246,7 +246,7 @@ jobs:
                   git push origin master
 
             - name: Publish release
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
               env:
                   RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                   FINAL: ${{ inputs.final }}

.github/workflows/release-npm.yml

@@ -25,7 +25,7 @@ jobs:
                   ref: staging
 
             - name: 🔧 Yarn cache
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/sonarcloud.yml

@@ -27,7 +27,7 @@ jobs:
         steps:
             # We create the status here and then update it to success/failure in the `report` stage
             # This provides an easy link to this workflow_run from the PR before Sonarcloud is done.
-            - uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+            - uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}
                   state: pending
@@ -87,7 +87,7 @@ jobs:
                   revision: ${{ github.event.workflow_run.head_sha }}
                   token: ${{ secrets.SONAR_TOKEN }}
 
-            - uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+            - uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
               if: always()
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/static_analysis.yml

@@ -16,7 +16,7 @@ jobs:
         steps:
             - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
 
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - 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@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: ${{ matrix.node }}
@@ -116,7 +116,7 @@ jobs:
         steps:
             - name: Skip SonarCloud on merge queues
               if: env.ENABLE_COVERAGE == 'false'
-              uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+              uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
               with:
                   authToken: ${{ secrets.GITHUB_TOKEN }}
                   state: success

.github/workflows/triage-stale.yml

@@ -12,7 +12,7 @@ jobs:
             issues: write
             pull-requests: write
         steps:
-            - uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9
+            - uses: actions/stale@5f858e3efba33a5ca4407a664cc011ad407f2008 # v10
               with:
                   operations-per-run: 250
                   days-before-issue-stale: -1

CHANGELOG.md

@@ -1,3 +1,47 @@
+Changes in [39.1.1](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.1.1) (2025-11-04)
+==================================================================================================
+Re-release of v39.1.0 to fix npm publishing workflow
+
+Changes in [39.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.1.0) (2025-11-04)
+==================================================================================================
+## ✨ Features
+
+* [MatrixRTC] Sticky Events support (MSC4354) ([#5017](https://github.com/matrix-org/matrix-js-sdk/pull/5017)). Contributed by @toger5.
+* Add `CryptoApi.getSecretStorageStatus` ([#5054](https://github.com/matrix-org/matrix-js-sdk/pull/5054)). Contributed by @richvdh.
+* Add parseCallNotificationContent ([#5015](https://github.com/matrix-org/matrix-js-sdk/pull/5015)). Contributed by @toger5.
+* MSC4140: support filters on delayed event lookup  ([#5038](https://github.com/matrix-org/matrix-js-sdk/pull/5038)). Contributed by @AndrewFerr.
+
+
+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
+
+* Add call intent to RTC call notifications ([#5010](https://github.com/matrix-org/matrix-js-sdk/pull/5010)). Contributed by @Half-Shot.
+* Implement experimental encrypted state events. ([#4994](https://github.com/matrix-org/matrix-js-sdk/pull/4994)). Contributed by @kaylendog.
+
+## 🐛 Bug Fixes
+
+* Exclude cancelled requests from in-progress lists ([#5016](https://github.com/matrix-org/matrix-js-sdk/pull/5016)). Contributed by @andybalaam.
+
+
 Changes in [38.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.3.0) (2025-09-23)
 ==================================================================================================
 ## 🐛 Bug Fixes

jest.config.ts

@@ -23,6 +23,7 @@ const config: Config = {
     collectCoverageFrom: ["<rootDir>/src/**/*.{js,ts}"],
     coverageReporters: ["text-summary", "lcov"],
     testResultsProcessor: "@casualbot/jest-sonar-reporter",
+    transformIgnorePatterns: ["/node_modules/(?!(uuid|p-retry|is-network-error)).+$"],
 
     // Always print out a summary if there are any failing tests. Normally
     // a summary is only printed if there are more than 20 test *suites*.

knip.ts

@@ -12,10 +12,6 @@ export default {
         "src/utils.ts", // not really an entrypoint but we have deprecated `defer` there
         "scripts/**",
         "spec/**",
-        // XXX: these look entirely unused
-        "src/crypto/aes.ts",
-        "src/crypto/crypto.ts",
-        "src/crypto/recoverykey.ts",
         // XXX: these should be re-exported by one of the supported exports
         "src/matrixrtc/index.ts",
         "src/sliding-sync.ts",

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "38.3.0",
+    "version": "39.1.1",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=22.0.0"
@@ -49,7 +49,7 @@
     ],
     "dependencies": {
         "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^15.2.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^15.3.0",
         "another-json": "^0.2.0",
         "bs58": "^6.0.0",
         "content-type": "^1.0.4",
@@ -58,10 +58,10 @@
         "matrix-events-sdk": "0.0.1",
         "matrix-widget-api": "^1.10.0",
         "oidc-client-ts": "^3.0.1",
-        "p-retry": "4",
+        "p-retry": "7",
         "sdp-transform": "^2.14.1",
         "unhomoglyph": "^1.0.6",
-        "uuid": "11"
+        "uuid": "13"
     },
     "devDependencies": {
         "@action-validator/cli": "^0.6.0",
@@ -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-jsdoc": "^50.0.0",
-        "eslint-plugin-matrix-org": "2.1.0",
+        "eslint-plugin-jest": "^29.0.0",
+        "eslint-plugin-jsdoc": "^61.0.0",
+        "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/integ/crypto/crypto.spec.ts

@@ -88,7 +88,10 @@ import {
     encryptMegolmEventRawPlainText,
     establishOlmSession,
     getTestOlmAccountKeys,
-} from "./olm-utils";
+    expectSendRoomKey,
+    expectSendMegolmMessageEvent,
+    expectEncryptedSendMessageEvent,
+} from "./olm-utils.ts";
 import { AccountDataAccumulator } from "../../test-utils/AccountDataAccumulator";
 import { UNSIGNED_MEMBERSHIP_FIELD } from "../../../src/@types/event";
 import { KnownMembership } from "../../../src/@types/membership";
@@ -104,107 +107,6 @@ afterEach(() => {
     jest.useRealTimers();
 });
 
-/**
- * Expect that the client shares keys with the given recipient
- *
- * Waits for an HTTP request to send the encrypted m.room_key to-device message; decrypts it and uses it
- * to establish an Olm InboundGroupSession.
- *
- * @param recipientUserID - the user id of the expected recipient
- *
- * @param recipientOlmAccount - Olm.Account for the recipient
- *
- * @param recipientOlmSession - an Olm.Session for the recipient, which must already have exchanged pre-key
- *    messages with the sender. Alternatively, null, in which case we will expect a pre-key message.
- *
- * @returns the established inbound group session
- */
-async function expectSendRoomKey(
-    recipientUserID: string,
-    recipientOlmAccount: Olm.Account,
-    recipientOlmSession: Olm.Session | null = null,
-): Promise<Olm.InboundGroupSession> {
-    const testRecipientKey = JSON.parse(recipientOlmAccount.identity_keys())["curve25519"];
-
-    function onSendRoomKey(content: any): Olm.InboundGroupSession {
-        const m = content.messages[recipientUserID].DEVICE_ID;
-        const ct = m.ciphertext[testRecipientKey];
-
-        if (!recipientOlmSession) {
-            expect(ct.type).toEqual(0); // pre-key message
-            recipientOlmSession = new Olm.Session();
-            recipientOlmSession.create_inbound(recipientOlmAccount, ct.body);
-        } else {
-            expect(ct.type).toEqual(1); // regular message
-        }
-
-        const decrypted = JSON.parse(recipientOlmSession.decrypt(ct.type, ct.body));
-        expect(decrypted.type).toEqual("m.room_key");
-        const inboundGroupSession = new Olm.InboundGroupSession();
-        inboundGroupSession.create(decrypted.content.session_key);
-        return inboundGroupSession;
-    }
-    return await new Promise<Olm.InboundGroupSession>((resolve) => {
-        fetchMock.putOnce(
-            new RegExp("/sendToDevice/m.room.encrypted/"),
-            (url: string, opts: RequestInit): FetchMock.MockResponse => {
-                const content = JSON.parse(opts.body as string);
-                resolve(onSendRoomKey(content));
-                return {};
-            },
-            {
-                // append to the list of intercepts on this path (since we have some tests that call
-                // this function multiple times)
-                overwriteRoutes: false,
-            },
-        );
-    });
-}
-
-/**
- * Return the event received on rooms/{roomId}/send/m.room.encrypted endpoint.
- * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
- * @returns the content of the encrypted event
- */
-function expectEncryptedSendMessage() {
-    return new Promise<IContent>((resolve) => {
-        fetchMock.putOnce(
-            new RegExp("/send/m.room.encrypted/"),
-            (url, request) => {
-                const content = JSON.parse(request.body as string);
-                resolve(content);
-                return { event_id: "$event_id" };
-            },
-            // append to the list of intercepts on this path (since we have some tests that call
-            // this function multiple times)
-            { overwriteRoutes: false },
-        );
-    });
-}
-
-/**
- * Expect that the client sends an encrypted event
- *
- * Waits for an HTTP request to send an encrypted message in the test room.
- *
- * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
- *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
- *
- * @returns The content of the successfully-decrypted event
- */
-async function expectSendMegolmMessage(
-    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
-): Promise<Partial<IEvent>> {
-    const encryptedMessageContent = await expectEncryptedSendMessage();
-
-    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
-    const inboundGroupSession = await inboundGroupSessionPromise;
-
-    const r: any = inboundGroupSession.decrypt(encryptedMessageContent!.ciphertext);
-    logger.log("Decrypted received megolm message", r);
-    return JSON.parse(r.plaintext);
-}
-
 describe("crypto", () => {
     let testOlmAccount = {} as unknown as Olm.Account;
     let testSenderKey = "";
@@ -991,7 +893,7 @@ describe("crypto", () => {
         // Finally, send the message, and expect to get an `m.room.encrypted` event that we can decrypt.
         await Promise.all([
             aliceClient.sendTextMessage(ROOM_ID, "test"),
-            expectSendMegolmMessage(inboundGroupSessionPromise),
+            expectSendMegolmMessageEvent(inboundGroupSessionPromise),
         ]);
     });
 
@@ -1018,7 +920,7 @@ describe("crypto", () => {
         // Send the first message, and check we can decrypt it.
         await Promise.all([
             aliceClient.sendTextMessage(ROOM_ID, "test"),
-            expectSendMegolmMessage(inboundGroupSessionPromise),
+            expectSendMegolmMessageEvent(inboundGroupSessionPromise),
         ]);
 
         // Finally the interesting part: discard the session.
@@ -1026,7 +928,7 @@ describe("crypto", () => {
 
         // Now when we send the next message, we should get a *new* megolm session.
         const inboundGroupSessionPromise2 = expectSendRoomKey("@bob:xyz", testOlmAccount);
-        const p2 = expectSendMegolmMessage(inboundGroupSessionPromise2);
+        const p2 = expectSendMegolmMessageEvent(inboundGroupSessionPromise2);
         await Promise.all([aliceClient.sendTextMessage(ROOM_ID, "test2"), p2]);
     });
 
@@ -1037,7 +939,7 @@ describe("crypto", () => {
          */
         async function sendEncryptedMessage(): Promise<IContent> {
             const [encryptedMessage] = await Promise.all([
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
                 aliceClient.sendTextMessage(ROOM_ID, "test"),
             ]);
             return encryptedMessage;
@@ -1159,7 +1061,7 @@ describe("crypto", () => {
         let [, , encryptedMessage] = await Promise.all([
             aliceClient.sendTextMessage(ROOM_ID, "test"),
             expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession),
-            expectEncryptedSendMessage(),
+            expectEncryptedSendMessageEvent(),
         ]);
 
         // Check that the session id exists
@@ -1187,7 +1089,7 @@ describe("crypto", () => {
         [, , encryptedMessage] = await Promise.all([
             aliceClient.sendTextMessage(ROOM_ID, "test"),
             expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession),
-            expectEncryptedSendMessage(),
+            expectEncryptedSendMessageEvent(),
         ]);
 
         // Check that the new session id exists
@@ -1385,7 +1287,7 @@ describe("crypto", () => {
             const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession);
 
             // and finally the megolm message
-            const megolmMessagePromise = expectSendMegolmMessage(inboundGroupSessionPromise);
+            const megolmMessagePromise = expectSendMegolmMessageEvent(inboundGroupSessionPromise);
 
             // kick it off
             const sendPromise = aliceClient.sendTextMessage(ROOM_ID, "test");
@@ -1408,7 +1310,7 @@ describe("crypto", () => {
             const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession);
 
             // and finally the megolm message
-            const megolmMessagePromise = expectSendMegolmMessage(inboundGroupSessionPromise);
+            const megolmMessagePromise = expectSendMegolmMessageEvent(inboundGroupSessionPromise);
 
             // kick it off
             const sendPromise = aliceClient.sendTextMessage(ROOM_ID, "test");
@@ -2300,7 +2202,7 @@ describe("crypto", () => {
             await syncPromise(client1);
 
             // Send a message, and expect to get an `m.room.encrypted` event.
-            await Promise.all([client1.sendTextMessage(ROOM_ID, "test"), expectEncryptedSendMessage()]);
+            await Promise.all([client1.sendTextMessage(ROOM_ID, "test"), expectEncryptedSendMessageEvent()]);
 
             // We now replace the client, and allow the new one to resync, *without* the encryption event.
             client2 = await replaceClient(client1);
@@ -2321,7 +2223,7 @@ describe("crypto", () => {
             // Send a message, and expect to get an `m.room.encrypted` event.
             const [, msg1Content] = await Promise.all([
                 client1.sendTextMessage(ROOM_ID, "test1"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
             ]);
 
             // Replace the state with one which bumps the rotation period. This should be ignored, though it's not
@@ -2340,12 +2242,12 @@ describe("crypto", () => {
             // use a different one.
             const [, msg2Content] = await Promise.all([
                 client1.sendTextMessage(ROOM_ID, "test2"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
             ]);
             expect(msg2Content.session_id).toEqual(msg1Content.session_id);
             const [, msg3Content] = await Promise.all([
                 client1.sendTextMessage(ROOM_ID, "test3"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
             ]);
             expect(msg3Content.session_id).not.toEqual(msg1Content.session_id);
         });
@@ -2357,7 +2259,7 @@ describe("crypto", () => {
             await syncPromise(client1);
 
             // Send a message, and expect to get an `m.room.encrypted` event.
-            await Promise.all([client1.sendTextMessage(ROOM_ID, "test1"), expectEncryptedSendMessage()]);
+            await Promise.all([client1.sendTextMessage(ROOM_ID, "test1"), expectEncryptedSendMessageEvent()]);
 
             // We now replace the client, and allow the new one to resync with a *different* encryption event.
             client2 = await replaceClient(client1);

spec/integ/crypto/olm-utils.ts

@@ -16,6 +16,7 @@ limitations under the License.
 
 import Olm from "@matrix-org/olm";
 import anotherjson from "another-json";
+import fetchMock from "fetch-mock-jest";
 
 import {
     type IContent,
@@ -30,6 +31,8 @@ import { type IE2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
 import { type ISyncResponder } from "../../test-utils/SyncResponder";
 import { syncPromise } from "../../test-utils/test-utils";
 import { type KeyBackupInfo } from "../../../src/crypto-api";
+import { logger } from "../../../src/logger";
+import type FetchMock from "fetch-mock";
 
 /**
  * @module
@@ -302,6 +305,7 @@ export function encryptMegolmEventRawPlainText(opts: {
         },
         type: "m.room.encrypted",
         unsigned: {},
+        state_key: opts.plaintext.state_key ? `${opts.plaintext.type}:${opts.plaintext.state_key}` : undefined,
     };
 }
 
@@ -414,3 +418,148 @@ export async function establishOlmSession(
     await syncPromise(testClient);
     return p2pSession;
 }
+
+/**
+ * Expect that the client shares keys with the given recipient
+ *
+ * Waits for an HTTP request to send the encrypted m.room_key to-device message; decrypts it and uses it
+ * to establish an Olm InboundGroupSession.
+ *
+ * @param recipientUserID - the user id of the expected recipient
+ *
+ * @param recipientOlmAccount - Olm.Account for the recipient
+ *
+ * @param recipientOlmSession - an Olm.Session for the recipient, which must already have exchanged pre-key
+ *    messages with the sender. Alternatively, null, in which case we will expect a pre-key message.
+ *
+ * @returns the established inbound group session
+ */
+export async function expectSendRoomKey(
+    recipientUserID: string,
+    recipientOlmAccount: Olm.Account,
+    recipientOlmSession: Olm.Session | null = null,
+): Promise<Olm.InboundGroupSession> {
+    const testRecipientKey = JSON.parse(recipientOlmAccount.identity_keys())["curve25519"];
+
+    function onSendRoomKey(content: any): Olm.InboundGroupSession {
+        const m = content.messages[recipientUserID].DEVICE_ID;
+        const ct = m.ciphertext[testRecipientKey];
+
+        if (!recipientOlmSession) {
+            expect(ct.type).toEqual(0); // pre-key message
+            recipientOlmSession = new Olm.Session();
+            recipientOlmSession.create_inbound(recipientOlmAccount, ct.body);
+        } else {
+            expect(ct.type).toEqual(1); // regular message
+        }
+
+        const decrypted = JSON.parse(recipientOlmSession.decrypt(ct.type, ct.body));
+        expect(decrypted.type).toEqual("m.room_key");
+        const inboundGroupSession = new Olm.InboundGroupSession();
+        inboundGroupSession.create(decrypted.content.session_key);
+        return inboundGroupSession;
+    }
+    return await new Promise<Olm.InboundGroupSession>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/sendToDevice/m.room.encrypted/"),
+            (url: string, opts: RequestInit): FetchMock.MockResponse => {
+                const content = JSON.parse(opts.body as string);
+                resolve(onSendRoomKey(content));
+                return {};
+            },
+            {
+                // append to the list of intercepts on this path (since we have some tests that call
+                // this function multiple times)
+                overwriteRoutes: false,
+            },
+        );
+    });
+}
+
+/**
+ * Return the event received on rooms/{roomId}/send/m.room.encrypted endpoint.
+ * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
+ * @returns the content of the encrypted event
+ */
+export function expectEncryptedSendMessageEvent() {
+    return new Promise<IContent>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/send/m.room.encrypted/"),
+            (url, request) => {
+                const content = JSON.parse(request.body as string);
+                resolve(content);
+                return { event_id: "$event_id" };
+            },
+            // append to the list of intercepts on this path (since we have some tests that call
+            // this function multiple times)
+            { overwriteRoutes: false },
+        );
+    });
+}
+
+/**
+ * Return the event received on rooms/{roomId}/state/m.room.encrypted/{stateKey} endpoint.
+ * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidstateeventtypestatekey
+ * @returns the content of the encrypted event
+ */
+function expectEncryptedSendStateEvent() {
+    return new Promise<IContent>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/state/m.room.encrypted/"),
+            (url, request) => {
+                const content = JSON.parse(request.body as string);
+                resolve(content);
+                return { event_id: "$event_id" };
+            },
+            // append to the list of intercepts on this path (since we have some tests that call
+            // this function multiple times)
+            { overwriteRoutes: false },
+        );
+    });
+}
+
+/**
+ * Expect that the client sends an encrypted message event
+ *
+ * Waits for an HTTP request to send an encrypted message in the test room.
+ *
+ * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
+ *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
+ *
+ * @returns The content of the successfully-decrypted event
+ */
+export async function expectSendMegolmMessageEvent(
+    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
+): Promise<Partial<IEvent>> {
+    const encryptedMessageContent = await expectEncryptedSendMessageEvent();
+
+    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
+    const inboundGroupSession = await inboundGroupSessionPromise;
+
+    const r: any = inboundGroupSession.decrypt(encryptedMessageContent!.ciphertext);
+    logger.log("Decrypted received megolm message", r);
+    return JSON.parse(r.plaintext);
+}
+
+/**
+ * Expect that the client sends an encrypted state event
+ *
+ * Waits for an HTTP request to send an encrypted state event in the test room.
+ *
+ * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
+ *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
+ *
+ * @returns The content of the successfully-decrypted state event
+ */
+export async function expectSendMegolmStateEvent(
+    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
+): Promise<Partial<IEvent>> {
+    const encryptedStateContent = await expectEncryptedSendStateEvent();
+
+    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
+    const inboundGroupSession = await inboundGroupSessionPromise;
+
+    const r: any = inboundGroupSession.decrypt(encryptedStateContent!.ciphertext);
+    logger.log("Decrypted received megolm state event", r);
+    return JSON.parse(r.plaintext);
+}

spec/integ/crypto/state-events.spec.ts

@@ -0,0 +1,219 @@
+/*
+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 anotherjson from "another-json";
+import fetchMock from "fetch-mock-jest";
+import "fake-indexeddb/auto";
+import Olm from "@matrix-org/olm";
+
+import * as testUtils from "../../test-utils/test-utils";
+import { getSyncResponse, syncPromise } from "../../test-utils/test-utils";
+import { TEST_ROOM_ID as ROOM_ID } from "../../test-utils/test-data";
+import { logger } from "../../../src/logger";
+import { createClient, PendingEventOrdering, type IStartClientOpts, type MatrixClient } from "../../../src/matrix";
+import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
+import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder";
+import { type ISyncResponder, SyncResponder } from "../../test-utils/SyncResponder";
+import {
+    createOlmAccount,
+    createOlmSession,
+    encryptGroupSessionKey,
+    encryptMegolmEvent,
+    getTestOlmAccountKeys,
+    expectSendRoomKey,
+    expectSendMegolmStateEvent,
+} from "./olm-utils";
+import { mockInitialApiRequests } from "../../test-utils/mockEndpoints";
+
+describe("Encrypted State Events", () => {
+    let testOlmAccount = {} as unknown as Olm.Account;
+    let testSenderKey = "";
+
+    /** the MatrixClient under test */
+    let aliceClient: MatrixClient;
+
+    /** an object which intercepts `/keys/upload` requests from {@link #aliceClient} to catch the uploaded keys */
+    let keyReceiver: E2EKeyReceiver;
+
+    /** an object which intercepts `/sync` requests from {@link #aliceClient} */
+    let syncResponder: ISyncResponder;
+
+    async function startClientAndAwaitFirstSync(opts: IStartClientOpts = {}): Promise<void> {
+        logger.log(aliceClient.getUserId() + ": starting");
+
+        mockInitialApiRequests(aliceClient.getHomeserverUrl());
+
+        // we let the client do a very basic initial sync, which it needs before
+        // it will upload one-time keys.
+        syncResponder.sendOrQueueSyncResponse({ next_batch: 1 });
+
+        aliceClient.startClient({
+            // set this so that we can get hold of failed events
+            pendingEventOrdering: PendingEventOrdering.Detached,
+            ...opts,
+        });
+
+        await syncPromise(aliceClient);
+        logger.log(aliceClient.getUserId() + ": started");
+    }
+
+    beforeEach(async () => {
+        fetchMock.catch(404);
+        fetchMock.config.warnOnFallback = false;
+
+        const homeserverUrl = "https://alice-server.com";
+        aliceClient = createClient({
+            baseUrl: homeserverUrl,
+            userId: "@alice:localhost",
+            accessToken: "akjgkrgjs",
+            deviceId: "xzcvb",
+            logger: logger.getChild("aliceClient"),
+            enableEncryptedStateEvents: true,
+        });
+
+        keyReceiver = new E2EKeyReceiver(homeserverUrl);
+        syncResponder = new SyncResponder(homeserverUrl);
+
+        await aliceClient.initRustCrypto();
+
+        // create a test olm device which we will use to communicate with alice. We use libolm to implement this.
+        testOlmAccount = await createOlmAccount();
+        const testE2eKeys = JSON.parse(testOlmAccount.identity_keys());
+        testSenderKey = testE2eKeys.curve25519;
+    }, 10000);
+
+    afterEach(async () => {
+        await aliceClient.stopClient();
+        await jest.runAllTimersAsync();
+        fetchMock.mockReset();
+    });
+
+    function expectAliceKeyQuery(response: any) {
+        fetchMock.postOnce(new RegExp("/keys/query"), (url: string, opts: RequestInit) => response, {
+            overwriteRoutes: false,
+        });
+    }
+
+    function expectAliceKeyClaim(response: any) {
+        fetchMock.postOnce(new RegExp("/keys/claim"), response);
+    }
+
+    function getTestKeysClaimResponse(userId: string) {
+        testOlmAccount.generate_one_time_keys(1);
+        const testOneTimeKeys = JSON.parse(testOlmAccount.one_time_keys());
+        testOlmAccount.mark_keys_as_published();
+
+        const keyId = Object.keys(testOneTimeKeys.curve25519)[0];
+        const oneTimeKey: string = testOneTimeKeys.curve25519[keyId];
+        const unsignedKeyResult = { key: oneTimeKey };
+        const j = anotherjson.stringify(unsignedKeyResult);
+        const sig = testOlmAccount.sign(j);
+        const keyResult = {
+            ...unsignedKeyResult,
+            signatures: { [userId]: { "ed25519:DEVICE_ID": sig } },
+        };
+
+        return {
+            one_time_keys: { [userId]: { DEVICE_ID: { ["signed_curve25519:" + keyId]: keyResult } } },
+            failures: {},
+        };
+    }
+
+    it("Should receive an encrypted state event", async () => {
+        expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
+        await startClientAndAwaitFirstSync();
+
+        const p2pSession = await createOlmSession(testOlmAccount, keyReceiver);
+        const groupSession = new Olm.OutboundGroupSession();
+        groupSession.create();
+
+        // make the room_key event
+        const roomKeyEncrypted = encryptGroupSessionKey({
+            recipient: aliceClient.getUserId()!,
+            recipientCurve25519Key: keyReceiver.getDeviceKey(),
+            recipientEd25519Key: keyReceiver.getSigningKey(),
+            olmAccount: testOlmAccount,
+            p2pSession: p2pSession,
+            groupSession: groupSession,
+            room_id: ROOM_ID,
+        });
+
+        // encrypt a state event with the group session
+        const eventEncrypted = encryptMegolmEvent({
+            senderKey: testSenderKey,
+            groupSession: groupSession,
+            room_id: ROOM_ID,
+            plaintext: {
+                type: "m.room.topic",
+                state_key: "",
+                content: {
+                    topic: "Secret!",
+                },
+            },
+        });
+
+        // Alice gets both the events in a single sync
+        const syncResponse = {
+            next_batch: 1,
+            to_device: {
+                events: [roomKeyEncrypted],
+            },
+            rooms: {
+                join: {
+                    [ROOM_ID]: { timeline: { events: [eventEncrypted] } },
+                },
+            },
+        };
+
+        syncResponder.sendOrQueueSyncResponse(syncResponse);
+        await syncPromise(aliceClient);
+
+        const room = aliceClient.getRoom(ROOM_ID)!;
+        const event = room.getLiveTimeline().getEvents()[0];
+        expect(event.isEncrypted()).toBe(true);
+
+        // it probably won't be decrypted yet, because it takes a while to process the olm keys
+        const decryptedEvent = await testUtils.awaitDecryption(event, { waitOnDecryptionFailure: true });
+        expect(decryptedEvent.getContent().topic).toEqual("Secret!");
+    });
+
+    it("Should send an encrypted state event", async () => {
+        const homeserverUrl = aliceClient.getHomeserverUrl();
+        const keyResponder = new E2EKeyResponder(homeserverUrl);
+        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);
+
+        const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
+        keyResponder.addDeviceKeys(testDeviceKeys);
+
+        await startClientAndAwaitFirstSync();
+
+        // Alice shares a room with Bob
+        syncResponder.sendOrQueueSyncResponse(getSyncResponse(["@bob:xyz"], ROOM_ID, true));
+        await syncPromise(aliceClient);
+
+        // ... and claim one of Bob's OTKs ...
+        expectAliceKeyClaim(getTestKeysClaimResponse("@bob:xyz"));
+
+        // ... and send an m.room.topic message
+        const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount);
+
+        // Finally, send the message, and expect to get an `m.room.encrypted` event that we can decrypt.
+        await Promise.all([
+            aliceClient.setRoomTopic(ROOM_ID, "Secret!"),
+            expectSendMegolmStateEvent(inboundGroupSessionPromise),
+        ]);
+    });
+});

spec/integ/crypto/verification.spec.ts

@@ -46,8 +46,8 @@ import {
     type Verifier,
     VerifierEvent,
 } from "../../../src/crypto-api/verification";
-import { escapeRegExp } from "../../../src/utils";
-import { awaitDecryption, emitPromise, getSyncResponse, syncPromise } from "../../test-utils/test-utils";
+import { escapeRegExp, sleep } from "../../../src/utils";
+import { awaitDecryption, emitPromise, getSyncResponse, syncPromise, waitFor } from "../../test-utils/test-utils";
 import { SyncResponder } from "../../test-utils/SyncResponder";
 import {
     BACKUP_DECRYPTION_KEY_BASE64,
@@ -79,11 +79,6 @@ import {
 import { type KeyBackupInfo, CryptoEvent } from "../../../src/crypto-api";
 import { encodeBase64 } from "../../../src/base64";
 
-// The verification flows use javascript timers to set timeouts. We tell jest to use mock timer implementations
-// to ensure that we don't end up with dangling timeouts.
-// But the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
-
 beforeAll(async () => {
     // we use the libolm primitives in the test, so init the Olm library
     await Olm.init();
@@ -96,6 +91,13 @@ beforeAll(async () => {
     await RustSdkCryptoJs.initAsync();
 }, 10000);
 
+beforeEach(() => {
+    // The verification flows use javascript timers to set timeouts. We tell jest to use mock timer implementations
+    // to ensure that we don't end up with dangling timeouts.
+    // But the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+    jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+});
+
 afterEach(() => {
     // reset fake-indexeddb after each test, to make sure we don't leak connections
     // cf https://github.com/dumbmatter/fakeIndexedDB#wipingresetting-the-indexeddb-for-a-fresh-state
@@ -735,6 +737,35 @@ describe("verification", () => {
             expect(request.cancellingUserId).toEqual("@alice:localhost");
         });
 
+        it("does not include cancelled requests in the list of requests", async () => {
+            // Given Alice started a verification request
+            const [, request] = await Promise.all([
+                expectSendToDeviceMessage("m.key.verification.request"),
+                aliceClient.getCrypto()!.requestDeviceVerification(TEST_USER_ID, TEST_DEVICE_ID),
+            ]);
+            const transactionId = request.transactionId!;
+
+            returnToDeviceMessageFromSync(buildReadyMessage(transactionId, ["m.sas.v1"]));
+            await waitForVerificationRequestChanged(request);
+
+            // Sanity: the request is listed
+            const requestsBeforeCancel = aliceClient
+                .getCrypto()!
+                .getVerificationRequestsToDeviceInProgress(TEST_USER_ID);
+
+            expect(requestsBeforeCancel).toHaveLength(1);
+
+            // When Alice cancels it
+            await Promise.all([expectSendToDeviceMessage("m.key.verification.cancel"), request.cancel()]);
+
+            // Then it is no longer listed as in progress
+            const requestsAfterCancel = aliceClient
+                .getCrypto()!
+                .getVerificationRequestsToDeviceInProgress(TEST_USER_ID);
+
+            expect(requestsAfterCancel).toHaveLength(0);
+        });
+
         it("can cancel during the SAS phase", async () => {
             // have alice initiate a verification. She should send a m.key.verification.request
             const [, request] = await Promise.all([
@@ -1051,6 +1082,13 @@ describe("verification", () => {
         });
 
         it("ignores old verification requests", async () => {
+            const debug = jest.fn();
+            const info = jest.fn();
+            const warn = jest.fn();
+
+            // @ts-ignore overriding RustCrypto's logger
+            aliceClient.getCrypto()!.logger = { debug, info, warn };
+
             const eventHandler = jest.fn();
             aliceClient.on(CryptoEvent.VerificationRequestReceived, eventHandler);
 
@@ -1065,6 +1103,16 @@ describe("verification", () => {
             const matrixEvent = room.getLiveTimeline().getEvents()[0];
             expect(matrixEvent.getId()).toEqual(verificationRequestEvent.event_id);
 
+            // Wait until the request has been processed. We use a real sleep()
+            // here to make sure any background async tasks are completed.
+            jest.useRealTimers();
+            await waitFor(async () => {
+                expect(info).toHaveBeenCalledWith(
+                    expect.stringMatching(/^Ignoring just-received verification request/),
+                );
+                sleep(100);
+            });
+
             // check that an event has not been raised, and that the request is not found
             expect(eventHandler).not.toHaveBeenCalled();
             expect(
@@ -1072,6 +1120,29 @@ describe("verification", () => {
             ).not.toBeDefined();
         });
 
+        it("ignores cancelled verification requests", async () => {
+            // Given a verification request exists
+            const event = createVerificationRequestEvent();
+            returnRoomMessageFromSync(TEST_ROOM_ID, event);
+
+            // Wait for the request to be received
+            await emitPromise(aliceClient, CryptoEvent.VerificationRequestReceived);
+
+            const request = aliceClient.getCrypto()!.findVerificationRequestDMInProgress(TEST_ROOM_ID, "@bob:xyz");
+
+            // When I cancel it
+            fetchMock.put("express:/_matrix/client/v3/rooms/:roomId/send/m.key.verification.cancel/:id", {
+                event_id: event.event_id,
+            });
+            await request!.cancel();
+            expect(request!.phase).toEqual(VerificationPhase.Cancelled);
+
+            // Then it is no longer found
+            expect(
+                aliceClient.getCrypto()!.findVerificationRequestDMInProgress(TEST_ROOM_ID, "@bob:xyz"),
+            ).not.toBeDefined();
+        });
+
         it("Plaintext verification request from Bob to Alice", async () => {
             // Add verification request from Bob to Alice in the DM between them
             returnRoomMessageFromSync(TEST_ROOM_ID, createVerificationRequestEvent());

spec/test-utils/test-utils.ts

@@ -63,7 +63,11 @@ export function syncPromise(client: MatrixClient, count = 1): Promise<void> {
  *
  * @returns the sync response
  */
-export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): ISyncResponse {
+export function getSyncResponse(
+    roomMembers: string[],
+    roomId = TEST_ROOM_ID,
+    encryptStateEvents = false,
+): ISyncResponse {
     const roomResponse: IJoinedRoom = {
         summary: {
             "m.heroes": [],
@@ -77,7 +81,8 @@ export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): I
                     type: "m.room.encryption",
                     state_key: "",
                     content: {
-                        algorithm: "m.megolm.v1.aes-sha2",
+                        "algorithm": "m.megolm.v1.aes-sha2",
+                        "io.element.msc3414.encrypt_state_events": encryptStateEvents,
                     },
                 }),
             ],

spec/unit/matrix-client.spec.ts

@@ -1053,17 +1053,28 @@ describe("MatrixClient", function () {
             );
         });
 
-        it("can look up delayed events", async () => {
-            httpLookups = [
-                {
-                    method: "GET",
-                    prefix: unstableMSC4140Prefix,
-                    path: "/delayed_events",
-                    data: [],
-                },
-            ];
+        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 () => {
@@ -2366,6 +2377,61 @@ describe("MatrixClient", function () {
         });
     });
 
+    describe("disableVoip option", () => {
+        const baseUrl = "https://alice-server.com";
+        const userId = "@alice:bar";
+        const accessToken = "sometoken";
+
+        beforeEach(() => {
+            mocked(supportsMatrixCall).mockReturnValue(true);
+        });
+
+        afterAll(() => {
+            mocked(supportsMatrixCall).mockReset();
+        });
+
+        it("should not call /voip/turnServer when disableVoip = true", () => {
+            fetchMock.getOnce(`${baseUrl}/_matrix/client/unstable/voip/turnServer`, 200);
+
+            const client = createClient({
+                baseUrl,
+                accessToken,
+                userId,
+                disableVoip: true,
+            });
+
+            // Only check createCall / supportsVoip, avoid startClient
+            expect(client.createCall("!roomId:example.com")).toBeNull();
+            expect(client.supportsVoip?.()).toBe(false);
+        });
+
+        it("should call /voip/turnServer when disableVoip is not set", () => {
+            fetchMock.getOnce(`${baseUrl}/_matrix/client/unstable/voip/turnServer`, {
+                uris: ["turn:turn.example.org"],
+            });
+
+            createClient({
+                baseUrl,
+                accessToken,
+                userId,
+            });
+
+            // The call will trigger the request if VoIP is supported
+            expect(fetchMock.called(`${baseUrl}/_matrix/client/unstable/voip/turnServer`)).toBe(false);
+        });
+
+        it("should return null from createCall when disableVoip = true", () => {
+            const client = createClient({
+                baseUrl,
+                accessToken,
+                userId,
+                disableVoip: true,
+            });
+
+            expect(client.createCall("!roomId:example.com")).toBeNull();
+        });
+    });
+
     describe("support for ignoring invites", () => {
         beforeEach(() => {
             // Mockup `getAccountData`/`setAccountData`.

spec/unit/matrixrtc/CallMembership.spec.ts

@@ -19,6 +19,7 @@ import {
     CallMembership,
     type SessionMembershipData,
     DEFAULT_EXPIRE_DURATION,
+    type RtcMembershipData,
 } from "../../../src/matrixrtc/CallMembership";
 import { membershipTemplate } from "./mocks";
 
@@ -26,6 +27,7 @@ function makeMockEvent(originTs = 0): MatrixEvent {
     return {
         getTs: jest.fn().mockReturnValue(originTs),
         getSender: jest.fn().mockReturnValue("@alice:example.org"),
+        getId: jest.fn().mockReturnValue("$eventid"),
     } as unknown as MatrixEvent;
 }
 
@@ -40,12 +42,13 @@ describe("CallMembership", () => {
         });
 
         const membershipTemplate: SessionMembershipData = {
-            call_id: "",
-            scope: "m.room",
-            application: "m.call",
-            device_id: "AAAAAAA",
-            focus_active: { type: "livekit" },
-            foci_preferred: [{ type: "livekit" }],
+            "call_id": "",
+            "scope": "m.room",
+            "application": "m.call",
+            "device_id": "AAAAAAA",
+            "focus_active": { type: "livekit", focus_selection: "oldest_membership" },
+            "foci_preferred": [{ type: "livekit" }],
+            "m.call.intent": "voice",
         };
 
         it("rejects membership with no device_id", () => {
@@ -94,11 +97,271 @@ describe("CallMembership", () => {
         it("returns preferred foci", () => {
             const fakeEvent = makeMockEvent();
             const mockFocus = { type: "this_is_a_mock_focus" };
-            const membership = new CallMembership(
-                fakeEvent,
-                Object.assign({}, membershipTemplate, { foci_preferred: [mockFocus] }),
-            );
-            expect(membership.getPreferredFoci()).toEqual([mockFocus]);
+            const membership = new CallMembership(fakeEvent, { ...membershipTemplate, foci_preferred: [mockFocus] });
+            expect(membership.transports).toEqual([mockFocus]);
+        });
+
+        describe("getTransport", () => {
+            const mockFocus = { type: "this_is_a_mock_focus" };
+            const oldestMembership = new CallMembership(makeMockEvent(), membershipTemplate);
+            it("gets the correct active transport with oldest_membership", () => {
+                const membership = new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    foci_preferred: [mockFocus],
+                    focus_active: { type: "livekit", focus_selection: "oldest_membership" },
+                });
+
+                // if we are the oldest member we use our focus.
+                expect(membership.getTransport(membership)).toStrictEqual(mockFocus);
+
+                // If there is an older member we use its focus.
+                expect(membership.getTransport(oldestMembership)).toBe(membershipTemplate.foci_preferred[0]);
+            });
+
+            it("gets the correct active transport with multi_sfu", () => {
+                const membership = new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    foci_preferred: [mockFocus],
+                    focus_active: { type: "livekit", focus_selection: "multi_sfu" },
+                });
+
+                // if we are the oldest member we use our focus.
+                expect(membership.getTransport(membership)).toStrictEqual(mockFocus);
+
+                // If there is an older member we still use our own focus in multi sfu.
+                expect(membership.getTransport(oldestMembership)).toBe(mockFocus);
+            });
+            it("does not provide focus if the selection method is unknown", () => {
+                const membership = new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    foci_preferred: [mockFocus],
+                    focus_active: { type: "livekit", focus_selection: "unknown" },
+                });
+
+                // if we are the oldest member we use our focus.
+                expect(membership.getTransport(membership)).toBeUndefined();
+            });
+        });
+        describe("correct values from computed fields", () => {
+            const membership = new CallMembership(makeMockEvent(), membershipTemplate);
+            it("returns correct sender", () => {
+                expect(membership.sender).toBe("@alice:example.org");
+            });
+            it("returns correct eventId", () => {
+                expect(membership.eventId).toBe("$eventid");
+            });
+            it("returns correct slot_id", () => {
+                expect(membership.slotId).toBe("m.call#");
+                expect(membership.slotDescription).toStrictEqual({ id: "", application: "m.call" });
+            });
+            it("returns correct deviceId", () => {
+                expect(membership.deviceId).toBe("AAAAAAA");
+            });
+            it("returns correct call intent", () => {
+                expect(membership.callIntent).toBe("voice");
+            });
+            it("returns correct application", () => {
+                expect(membership.application).toStrictEqual("m.call");
+            });
+            it("returns correct applicationData", () => {
+                expect(membership.applicationData).toStrictEqual({ "type": "m.call", "m.call.intent": "voice" });
+            });
+            it("returns correct scope", () => {
+                expect(membership.scope).toBe("m.room");
+            });
+            it("returns correct membershipID", () => {
+                expect(membership.membershipID).toBe("0");
+            });
+            it("returns correct unused fields", () => {
+                expect(membership.getAbsoluteExpiry()).toBe(DEFAULT_EXPIRE_DURATION);
+                expect(membership.getMsUntilExpiry()).toBe(DEFAULT_EXPIRE_DURATION - Date.now());
+                expect(membership.isExpired()).toBe(true);
+            });
+        });
+    });
+
+    describe("RtcMembershipData", () => {
+        const membershipTemplate: RtcMembershipData = {
+            slot_id: "m.call#",
+            application: { "type": "m.call", "m.call.id": "", "m.call.intent": "voice" },
+            member: { user_id: "@alice:example.org", device_id: "AAAAAAA", id: "xyzHASHxyz" },
+            rtc_transports: [{ type: "livekit" }],
+            versions: [],
+            msc4354_sticky_key: "abc123",
+        };
+
+        it("rejects membership with no slot_id", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, slot_id: undefined });
+            }).toThrow();
+        });
+        it("rejects membership with invalid slot_id", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, slot_id: "invalid_slot_id" });
+            }).toThrow();
+        });
+        it("accepts membership with valid slot_id", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, slot_id: "m.call#" });
+            }).not.toThrow();
+        });
+
+        it("rejects membership with no application", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, application: undefined });
+            }).toThrow();
+        });
+
+        it("rejects membership with incorrect application", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    application: { wrong_type_key: "unknown" },
+                });
+            }).toThrow();
+        });
+
+        it("rejects membership with no member", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, member: undefined });
+            }).toThrow();
+        });
+
+        it("rejects membership with incorrect  member", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, member: { i: "test" } });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    member: { id: "test", device_id: "test", user_id_wrong: "test" },
+                });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    member: { id: "test", device_id_wrong: "test", user_id_wrong: "test" },
+                });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    member: { id: "test", device_id: "test", user_id: "@@test" },
+                });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    member: { id: "test", device_id: "test", user_id: "@test-wrong-user:user.id" },
+                });
+            }).toThrow();
+        });
+        it("rejects membership with incorrect sticky_key", () => {
+            expect(() => {
+                new CallMembership(makeMockEvent(), membershipTemplate);
+            }).not.toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    sticky_key: 1,
+                    msc4354_sticky_key: undefined,
+                });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    sticky_key: "1",
+                    msc4354_sticky_key: undefined,
+                });
+            }).not.toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), { ...membershipTemplate, msc4354_sticky_key: undefined });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    msc4354_sticky_key: 1,
+                    sticky_key: "valid",
+                });
+            }).toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    msc4354_sticky_key: "valid",
+                    sticky_key: "valid",
+                });
+            }).not.toThrow();
+            expect(() => {
+                new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    msc4354_sticky_key: "valid_but_different",
+                    sticky_key: "valid",
+                });
+            }).toThrow();
+        });
+
+        it("considers memberships unexpired if local age low enough", () => {
+            // TODO link prev event
+        });
+
+        it("considers memberships expired if local age large enough", () => {
+            // TODO link prev event
+        });
+
+        describe("getTransport", () => {
+            it("gets the correct active transport with oldest_membership", () => {
+                const oldestMembership = new CallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    rtc_transports: [{ type: "oldest_transport" }],
+                });
+                const membership = new CallMembership(makeMockEvent(), membershipTemplate);
+
+                // if we are the oldest member we use our focus.
+                expect(membership.getTransport(membership)).toStrictEqual({ type: "livekit" });
+
+                // If there is an older member we use our own focus focus. (RtcMembershipData always uses multi sfu)
+                expect(membership.getTransport(oldestMembership)).toStrictEqual({ type: "livekit" });
+            });
+        });
+        describe("correct values from computed fields", () => {
+            const membership = new CallMembership(makeMockEvent(), membershipTemplate);
+            it("returns correct sender", () => {
+                expect(membership.sender).toBe("@alice:example.org");
+            });
+            it("returns correct eventId", () => {
+                expect(membership.eventId).toBe("$eventid");
+            });
+            it("returns correct slot_id", () => {
+                expect(membership.slotId).toBe("m.call#");
+                expect(membership.slotDescription).toStrictEqual({ id: "", application: "m.call" });
+            });
+            it("returns correct deviceId", () => {
+                expect(membership.deviceId).toBe("AAAAAAA");
+            });
+            it("returns correct call intent", () => {
+                expect(membership.callIntent).toBe("voice");
+            });
+            it("returns correct application", () => {
+                expect(membership.application).toStrictEqual("m.call");
+            });
+            it("returns correct applicationData", () => {
+                expect(membership.applicationData).toStrictEqual({
+                    "type": "m.call",
+                    "m.call.id": "",
+                    "m.call.intent": "voice",
+                });
+            });
+            it("returns correct scope", () => {
+                expect(membership.scope).toBe(undefined);
+            });
+            it("returns correct membershipID", () => {
+                expect(membership.membershipID).toBe("xyzHASHxyz");
+            });
+            it("returns correct unused fields", () => {
+                expect(membership.getAbsoluteExpiry()).toBe(undefined);
+                expect(membership.getMsUntilExpiry()).toBe(undefined);
+                expect(membership.isExpired()).toBe(false);
+            });
         });
     });
 

spec/unit/matrixrtc/LivekitTransport.spec.ts

@@ -14,47 +14,51 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { isLivekitFocus, isLivekitFocusActive, isLivekitFocusConfig } from "../../../src/matrixrtc/LivekitFocus";
+import {
+    isLivekitTransport,
+    isLivekitFocusSelection,
+    isLivekitTransportConfig,
+} from "../../../src/matrixrtc/LivekitTransport";
 
 describe("LivekitFocus", () => {
     it("isLivekitFocus", () => {
         expect(
-            isLivekitFocus({
+            isLivekitTransport({
                 type: "livekit",
                 livekit_service_url: "http://test.com",
                 livekit_alias: "test",
             }),
         ).toBeTruthy();
-        expect(isLivekitFocus({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitTransport({ type: "livekit" })).toBeFalsy();
         expect(
-            isLivekitFocus({ type: "not-livekit", livekit_service_url: "http://test.com", livekit_alias: "test" }),
+            isLivekitTransport({ type: "not-livekit", livekit_service_url: "http://test.com", livekit_alias: "test" }),
         ).toBeFalsy();
         expect(
-            isLivekitFocus({ type: "livekit", other_service_url: "http://test.com", livekit_alias: "test" }),
+            isLivekitTransport({ type: "livekit", other_service_url: "http://test.com", livekit_alias: "test" }),
         ).toBeFalsy();
         expect(
-            isLivekitFocus({ type: "livekit", livekit_service_url: "http://test.com", other_alias: "test" }),
+            isLivekitTransport({ type: "livekit", livekit_service_url: "http://test.com", other_alias: "test" }),
         ).toBeFalsy();
     });
     it("isLivekitFocusActive", () => {
         expect(
-            isLivekitFocusActive({
+            isLivekitFocusSelection({
                 type: "livekit",
                 focus_selection: "oldest_membership",
             }),
         ).toBeTruthy();
-        expect(isLivekitFocusActive({ type: "livekit" })).toBeFalsy();
-        expect(isLivekitFocusActive({ type: "not-livekit", focus_selection: "oldest_membership" })).toBeFalsy();
+        expect(isLivekitFocusSelection({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitFocusSelection({ type: "not-livekit", focus_selection: "oldest_membership" })).toBeFalsy();
     });
     it("isLivekitFocusConfig", () => {
         expect(
-            isLivekitFocusConfig({
+            isLivekitTransportConfig({
                 type: "livekit",
                 livekit_service_url: "http://test.com",
             }),
         ).toBeTruthy();
-        expect(isLivekitFocusConfig({ type: "livekit" })).toBeFalsy();
-        expect(isLivekitFocusConfig({ type: "not-livekit", livekit_service_url: "http://test.com" })).toBeFalsy();
-        expect(isLivekitFocusConfig({ type: "livekit", other_service_url: "oldest_membership" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "not-livekit", livekit_service_url: "http://test.com" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "livekit", other_service_url: "oldest_membership" })).toBeFalsy();
     });
 });

spec/unit/matrixrtc/MatrixRTCSession.spec.ts

@@ -14,13 +14,30 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { encodeBase64, EventType, MatrixClient, type MatrixError, type MatrixEvent, type Room } from "../../../src";
+import {
+    encodeBase64,
+    type EventTimeline,
+    EventType,
+    MatrixClient,
+    type MatrixError,
+    type MatrixEvent,
+    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, membershipTemplate, makeKey, type MembershipData, mockRoomState } from "./mocks";
+import {
+    makeMockEvent,
+    makeMockRoom,
+    membershipTemplate,
+    makeKey,
+    type MembershipData,
+    mockRoomState,
+    mockRTCEvent,
+} 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: "mock" };
 
@@ -47,162 +64,362 @@ describe("MatrixRTCSession", () => {
         sess = undefined;
     });
 
-    describe("roomSessionForRoom", () => {
-        it("creates a room-scoped session from room state", () => {
-            const mockRoom = makeMockRoom([membershipTemplate]);
+    describe.each([
+        {
+            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(() => {
+                        MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, testConfig);
+                    }).toThrow();
+                } else {
+                    // eslint-disable-next-line jest/no-conditional-expect
+                    expect(() => {
+                        MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, testConfig);
+                    }).not.toThrow();
+                }
+            });
 
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+            it("creates a room-scoped session from room state", () => {
+                const mockRoom = makeMockRoom([membershipTemplate], testConfig.testCreateSticky);
+
+                sess = 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");
+                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("ignores memberships where application is not m.call", () => {
+                const testMembership = Object.assign({}, membershipTemplate, {
+                    application: "not-m.call",
+                });
+                const mockRoom = makeMockRoom([testMembership], testConfig.testCreateSticky);
+                const sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships).toHaveLength(0);
+            });
+
+            it("ignores memberships where callId is not empty", () => {
+                const testMembership = Object.assign({}, membershipTemplate, {
+                    call_id: "not-empty",
+                    scope: "m.room",
+                });
+                const mockRoom = makeMockRoom([testMembership], testConfig.testCreateSticky);
+                const sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships).toHaveLength(0);
+            });
+
+            it("ignores expired memberships events", () => {
+                jest.useFakeTimers();
+                const expiredMembership = Object.assign({}, membershipTemplate);
+                expiredMembership.expires = 1000;
+                expiredMembership.device_id = "EXPIRED";
+                const mockRoom = makeMockRoom([membershipTemplate, expiredMembership], testConfig.testCreateSticky);
+
+                jest.advanceTimersByTime(2000);
+                sess = 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", () => {
+                const mockRoom = makeMockRoom([membershipTemplate], testConfig.testCreateSticky);
+                mockRoom.hasMembershipState.mockImplementation((state) => state === KnownMembership.Join);
+                sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships.length).toEqual(0);
+            });
+
+            it("ignores memberships events with no sender", () => {
+                // Force the sender to be undefined.
+                const mockRoom = makeMockRoom([{ ...membershipTemplate, user_id: "" }], testConfig.testCreateSticky);
+                mockRoom.hasMembershipState.mockImplementation((state) => state === KnownMembership.Join);
+                sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships.length).toEqual(0);
+            });
+
+            it("honours created_ts", () => {
+                jest.useFakeTimers();
+                jest.setSystemTime(500);
+                const expiredMembership = Object.assign({}, membershipTemplate);
+                expiredMembership.created_ts = 500;
+                expiredMembership.expires = 1000;
+                const mockRoom = makeMockRoom([expiredMembership], testConfig.testCreateSticky);
+                sess = 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", () => {
+                const mockRoom = makeMockRoom([], testConfig.testCreateSticky);
+                sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess?.memberships).toHaveLength(0);
+            });
+
+            it("safely ignores events with no memberships section", () => {
+                const event = {
+                    getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
+                    getContent: jest.fn().mockReturnValue({}),
+                    getSender: jest.fn().mockReturnValue("@mock:user.example"),
+                    getTs: jest.fn().mockReturnValue(1000),
+                    getLocalAge: jest.fn().mockReturnValue(0),
+                };
+                const mockRoom = makeMockRoom([]);
+                mockRoom.getLiveTimeline.mockReturnValue({
+                    getState: jest.fn().mockReturnValue({
+                        on: jest.fn(),
+                        off: jest.fn(),
+                        getStateEvents: (_type: string, _stateKey: string) => [event],
+                        events: new Map([
+                            [
+                                EventType.GroupCallMemberPrefix,
+                                {
+                                    size: () => true,
+                                    has: (_stateKey: string) => true,
+                                    get: (_stateKey: string) => event,
+                                    values: () => [event],
+                                },
+                            ],
+                        ]),
+                    }),
+                } as unknown as EventTimeline);
+                sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess.memberships).toHaveLength(0);
+            });
+
+            it("safely ignores events with junk memberships section", () => {
+                const event = {
+                    getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
+                    getContent: jest.fn().mockReturnValue({ memberships: ["i am a fish"] }),
+                    getSender: jest.fn().mockReturnValue("@mock:user.example"),
+                    getTs: jest.fn().mockReturnValue(1000),
+                    getLocalAge: jest.fn().mockReturnValue(0),
+                };
+                const mockRoom = makeMockRoom([]);
+                mockRoom.getLiveTimeline.mockReturnValue({
+                    getState: jest.fn().mockReturnValue({
+                        on: jest.fn(),
+                        off: jest.fn(),
+                        getStateEvents: (_type: string, _stateKey: string) => [event],
+                        events: new Map([
+                            [
+                                EventType.GroupCallMemberPrefix,
+                                {
+                                    size: () => true,
+                                    has: (_stateKey: string) => true,
+                                    get: (_stateKey: string) => event,
+                                    values: () => [event],
+                                },
+                            ],
+                        ]),
+                    }),
+                } as unknown as EventTimeline);
+                sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess.memberships).toHaveLength(0);
+            });
+
+            it("ignores memberships with no device_id", () => {
+                const testMembership = Object.assign({}, membershipTemplate);
+                (testMembership.device_id as string | undefined) = undefined;
+                const mockRoom = makeMockRoom([testMembership]);
+                const sess = MatrixRTCSession.sessionForSlot(
+                    client,
+                    mockRoom,
+                    callSession,
+                    testConfig.createWithDefaults ? undefined : testConfig,
+                );
+                expect(sess.memberships).toHaveLength(0);
+            });
+
+            it("ignores memberships with no call_id", () => {
+                const testMembership = Object.assign({}, membershipTemplate);
+                (testMembership.call_id as string | undefined) = undefined;
+                const mockRoom = makeMockRoom([testMembership]);
+                sess = 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", () => {
+            // 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 = MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, {
+                listenForStickyEvents: true,
+                listenForMemberStateEvents: true,
+            });
             expect(sess?.memberships.length).toEqual(1);
-            expect(sess?.memberships[0].sessionDescription.id).toEqual("");
+            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?.sessionDescription.id).toEqual("");
+            expect(sess?.slotDescription.id).toEqual("");
         });
-
-        it("ignores memberships where application is not m.call", () => {
-            const testMembership = Object.assign({}, membershipTemplate, {
-                application: "not-m.call",
-            });
-            const mockRoom = makeMockRoom([testMembership]);
-            const sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess?.memberships).toHaveLength(0);
-        });
-
-        it("ignores memberships where callId is not empty", () => {
-            const testMembership = Object.assign({}, membershipTemplate, {
-                call_id: "not-empty",
-                scope: "m.room",
-            });
-            const mockRoom = makeMockRoom([testMembership]);
-            const sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess?.memberships).toHaveLength(0);
-        });
-
-        it("ignores expired memberships events", () => {
-            jest.useFakeTimers();
-            const expiredMembership = Object.assign({}, membershipTemplate);
-            expiredMembership.expires = 1000;
-            expiredMembership.device_id = "EXPIRED";
-            const mockRoom = makeMockRoom([membershipTemplate, expiredMembership]);
-
-            jest.advanceTimersByTime(2000);
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            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", () => {
+        it("combines sticky and membership events when both exist", () => {
+            // Create a room with identical member state and sticky state for the same user.
             const mockRoom = makeMockRoom([membershipTemplate]);
-            mockRoom.hasMembershipState = (state) => state === KnownMembership.Join;
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess?.memberships.length).toEqual(0);
-        });
+            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];
+            });
 
-        it("honours created_ts", () => {
-            jest.useFakeTimers();
-            jest.setSystemTime(500);
-            const expiredMembership = Object.assign({}, membershipTemplate);
-            expiredMembership.created_ts = 500;
-            expiredMembership.expires = 1000;
-            const mockRoom = makeMockRoom([expiredMembership]);
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess?.memberships[0].getAbsoluteExpiry()).toEqual(1500);
-            jest.useRealTimers();
-        });
+            sess = MatrixRTCSession.sessionForSlot(client, mockRoom, callSession, {
+                listenForStickyEvents: true,
+                listenForMemberStateEvents: true,
+            });
 
-        it("returns empty session if no membership events are present", () => {
-            const mockRoom = makeMockRoom([]);
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess?.memberships).toHaveLength(0);
-        });
+            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);
 
-        it("safely ignores events with no memberships section", () => {
-            const roomId = secureRandomString(8);
-            const event = {
-                getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
-                getContent: jest.fn().mockReturnValue({}),
-                getSender: jest.fn().mockReturnValue("@mock:user.example"),
-                getTs: jest.fn().mockReturnValue(1000),
-                getLocalAge: jest.fn().mockReturnValue(0),
-            };
-            const mockRoom = {
-                ...makeMockRoom([]),
-                roomId,
-                getLiveTimeline: jest.fn().mockReturnValue({
-                    getState: jest.fn().mockReturnValue({
-                        on: jest.fn(),
-                        off: jest.fn(),
-                        getStateEvents: (_type: string, _stateKey: string) => [event],
-                        events: new Map([
-                            [
-                                EventType.GroupCallMemberPrefix,
-                                {
-                                    size: () => true,
-                                    has: (_stateKey: string) => true,
-                                    get: (_stateKey: string) => event,
-                                    values: () => [event],
-                                },
-                            ],
-                        ]),
-                    }),
-                }),
-            };
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom as unknown as Room, callSession);
-            expect(sess.memberships).toHaveLength(0);
-        });
+            // Then state
+            expect(memberships[1].sender).toEqual(membershipTemplate.user_id);
 
-        it("safely ignores events with junk memberships section", () => {
-            const roomId = secureRandomString(8);
-            const event = {
-                getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
-                getContent: jest.fn().mockReturnValue({ memberships: ["i am a fish"] }),
-                getSender: jest.fn().mockReturnValue("@mock:user.example"),
-                getTs: jest.fn().mockReturnValue(1000),
-                getLocalAge: jest.fn().mockReturnValue(0),
-            };
-            const mockRoom = {
-                ...makeMockRoom([]),
-                roomId,
-                getLiveTimeline: jest.fn().mockReturnValue({
-                    getState: jest.fn().mockReturnValue({
-                        on: jest.fn(),
-                        off: jest.fn(),
-                        getStateEvents: (_type: string, _stateKey: string) => [event],
-                        events: new Map([
-                            [
-                                EventType.GroupCallMemberPrefix,
-                                {
-                                    size: () => true,
-                                    has: (_stateKey: string) => true,
-                                    get: (_stateKey: string) => event,
-                                    values: () => [event],
-                                },
-                            ],
-                        ]),
-                    }),
-                }),
-            };
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom as unknown as Room, callSession);
-            expect(sess.memberships).toHaveLength(0);
+            expect(sess?.slotDescription.id).toEqual("");
         });
+        it("handles an incoming sticky event to an existing session", () => {
+            const mockRoom = makeMockRoom([membershipTemplate]);
+            const stickyUserId = "@stickyev:user.example";
 
-        it("ignores memberships with no device_id", () => {
-            const testMembership = Object.assign({}, membershipTemplate);
-            (testMembership.device_id as string | undefined) = undefined;
-            const mockRoom = makeMockRoom([testMembership]);
-            const sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess.memberships).toHaveLength(0);
-        });
-
-        it("ignores memberships with no call_id", () => {
-            const testMembership = Object.assign({}, membershipTemplate);
-            (testMembership.call_id as string | undefined) = undefined;
-            const mockRoom = makeMockRoom([testMembership]);
-            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
-            expect(sess.memberships).toHaveLength(0);
+            sess = 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);
         });
     });
 
@@ -222,6 +439,27 @@ describe("MatrixRTCSession", () => {
         });
     });
 
+    describe("getConsensusCallIntent", () => {
+        it.each([
+            [undefined, undefined, undefined],
+            ["audio", undefined, "audio"],
+            [undefined, "audio", "audio"],
+            ["audio", "audio", "audio"],
+            ["audio", "video", undefined],
+        ])("gets correct consensus for %s + %s = %s", (intentA, intentB, result) => {
+            jest.useFakeTimers();
+            jest.setSystemTime(4000);
+            const mockRoom = makeMockRoom([
+                Object.assign({}, membershipTemplate, { "m.call.intent": intentA }),
+                Object.assign({}, membershipTemplate, { "m.call.intent": intentB }),
+            ]);
+
+            sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
+            expect(sess.getConsensusCallIntent()).toEqual(result);
+            jest.useRealTimers();
+        });
+    });
+
     describe("getsActiveFocus", () => {
         const firstPreferredFocus = {
             type: "livekit",
@@ -247,7 +485,6 @@ describe("MatrixRTCSession", () => {
                 type: "livekit",
                 focus_selection: "oldest_membership",
             });
-            expect(sess.getActiveFocus()).toBe(firstPreferredFocus);
             jest.useRealTimers();
         });
         it("does not provide focus if the selection method is unknown", () => {
@@ -267,7 +504,7 @@ describe("MatrixRTCSession", () => {
                 type: "livekit",
                 focus_selection: "unknown",
             });
-            expect(sess.getActiveFocus()).toBe(undefined);
+            expect(sess.memberships.length).toBe(0);
         });
     });
 
@@ -309,6 +546,12 @@ 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
@@ -370,6 +613,79 @@ describe("MatrixRTCSession", () => {
             );
         });
 
+        it("sends a notification with a intent when starting a call and emits DidSendCallNotification", async () => {
+            // Simulate a join, including the update to the room state
+            // Ensure sendEvent returns event IDs so the DidSendCallNotification payload includes them
+            sendEventMock
+                .mockResolvedValueOnce({ event_id: "legacy-evt" })
+                .mockResolvedValueOnce({ event_id: "new-evt" });
+            const didSendEventFn = jest.fn();
+            sess!.once(MatrixRTCSessionEvent.DidSendCallNotification, didSendEventFn);
+            // Create an additional listener to create a promise that resolves after the emission.
+            const didSendNotification = new Promise((resolve) => {
+                sess!.once(MatrixRTCSessionEvent.DidSendCallNotification, resolve);
+            });
+
+            sess!.joinRoomSession([mockFocus], mockFocus, { notificationType: "ring", callIntent: "audio" });
+            await Promise.race([sentStateEvent, new Promise((resolve) => setTimeout(resolve, 5000))]);
+
+            mockRoomState(mockRoom, [
+                {
+                    ...membershipTemplate,
+                    "user_id": client.getUserId()!,
+                    // This is what triggers the intent type on the notification event.
+                    "m.call.intent": "audio",
+                },
+            ]);
+
+            sess!.onRTCSessionMemberUpdate();
+            const ownMembershipId = sess?.memberships[0].eventId;
+            expect(sess!.getConsensusCallIntent()).toEqual("audio");
+
+            expect(client.sendEvent).toHaveBeenCalledWith(mockRoom!.roomId, EventType.RTCNotification, {
+                "m.mentions": { user_ids: [], room: true },
+                "notification_type": "ring",
+                "m.call.intent": "audio",
+                "m.relates_to": {
+                    event_id: ownMembershipId,
+                    rel_type: "m.reference",
+                },
+                "lifetime": 30000,
+                "sender_ts": expect.any(Number),
+            });
+
+            // Check if deprecated notify event is also sent.
+            expect(client.sendEvent).toHaveBeenCalledWith(mockRoom!.roomId, EventType.CallNotify, {
+                "application": "m.call",
+                "m.mentions": { user_ids: [], room: true },
+                "notify_type": "ring",
+                "call_id": "",
+            });
+            await didSendNotification;
+            // And ensure we emitted the DidSendCallNotification event with both payloads
+            expect(didSendEventFn).toHaveBeenCalledWith(
+                {
+                    "event_id": "new-evt",
+                    "lifetime": 30000,
+                    "m.mentions": { room: true, user_ids: [] },
+                    "m.relates_to": {
+                        event_id: expect.any(String),
+                        rel_type: "m.reference",
+                    },
+                    "notification_type": "ring",
+                    "m.call.intent": "audio",
+                    "sender_ts": expect.any(Number),
+                },
+                {
+                    "application": "m.call",
+                    "call_id": "",
+                    "event_id": "legacy-evt",
+                    "m.mentions": { room: true, user_ids: [] },
+                    "notify_type": "ring",
+                },
+            );
+        });
+
         it("doesn't send a notification when joining an existing call", async () => {
             // Add another member to the call so that it is considered an existing call
             mockRoomState(mockRoom, [membershipTemplate]);

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -14,136 +14,145 @@ 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, membershipTemplate, mockRoomState } from "./mocks";
+import { makeMockRoom, type MembershipData, membershipTemplate, mockRoomState, mockRTCEvent } from "./mocks";
 import { logger } from "../../../src/logger";
 
-describe("MatrixRTCSessionManager", () => {
-    let client: MatrixClient;
+describe.each([{ eventKind: "sticky" }, { eventKind: "memberState" }])(
+    "MatrixRTCSessionManager ($eventKind)",
+    ({ eventKind }) => {
+        let client: MatrixClient;
 
-    beforeEach(() => {
-        client = new MatrixClient({ baseUrl: "base_url" });
-        client.matrixRTC.start();
-    });
-
-    afterEach(() => {
-        client.stopClient();
-        client.matrixRTC.stop();
-    });
-
-    it("Fires event when session starts", () => {
-        const onStarted = jest.fn();
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
-
-        try {
-            const room1 = makeMockRoom([membershipTemplate]);
-            jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-
-            client.emit(ClientEvent.Room, room1);
-            expect(onStarted).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
-        } finally {
-            client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+        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));
+            }
         }
-    });
 
-    it("Doesn't fire event if unrelated sessions starts", () => {
-        const onStarted = jest.fn();
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+        beforeEach(() => {
+            client = new MatrixClient({ baseUrl: "base_url" });
+            client.matrixRTC.start();
+        });
 
-        try {
-            const room1 = makeMockRoom([{ ...membershipTemplate, application: "m.other" }]);
+        afterEach(() => {
+            client.stopClient();
+            client.matrixRTC.stop();
+        });
+
+        it("Fires event when session starts", () => {
+            const onStarted = jest.fn();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+
+            try {
+                const room1 = makeMockRoom([membershipTemplate], eventKind === "sticky");
+                jest.spyOn(client, "getRooms").mockReturnValue([room1]);
+
+                client.emit(ClientEvent.Room, room1);
+                expect(onStarted).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
+            } finally {
+                client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+            }
+        });
+
+        it("Doesn't fire event if unrelated sessions starts", () => {
+            const onStarted = jest.fn();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+
+            try {
+                const room1 = makeMockRoom([{ ...membershipTemplate, application: "m.other" }], eventKind === "sticky");
+                jest.spyOn(client, "getRooms").mockReturnValue([room1]);
+
+                client.emit(ClientEvent.Room, room1);
+                expect(onStarted).not.toHaveBeenCalled();
+            } finally {
+                client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+            }
+        });
+
+        it("Fires event when session ends", () => {
+            const onEnded = jest.fn();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
+            const membershipData: MembershipData[] = [membershipTemplate];
+            const room1 = makeMockRoom(membershipData, eventKind === "sticky");
             jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-
+            jest.spyOn(client, "getRoom").mockReturnValue(room1);
             client.emit(ClientEvent.Room, room1);
-            expect(onStarted).not.toHaveBeenCalled();
-        } finally {
-            client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
-        }
-    });
 
-    it("Fires event when session ends", () => {
-        const onEnded = jest.fn();
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        const room1 = makeMockRoom([membershipTemplate]);
-        jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-        jest.spyOn(client, "getRoom").mockReturnValue(room1);
+            sendLeaveMembership(room1, membershipData);
 
-        client.emit(ClientEvent.Room, room1);
+            expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
+        });
 
-        mockRoomState(room1, [{ user_id: membershipTemplate.user_id }]);
+        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 roomState = room1.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
-        const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
-        client.emit(RoomStateEvent.Events, membEvent, roomState, null);
+            // manually start the session manager (its not the default one started by the client)
+            sessionManager.start();
+            sessionManager.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
+            sessionManager.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
 
-        expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
-    });
+            try {
+                // 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();
 
-    it("Fires correctly with for 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" });
+                // 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);
+                expect(onStarted).toHaveBeenCalled();
+                onStarted.mockClear();
 
-        // manually start the session manager (its not the default one started by the client)
-        sessionManager.start();
-        sessionManager.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        sessionManager.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+                // Stop room1's RTC session. Tracked.
+                jest.spyOn(client, "getRoom").mockReturnValue(room2);
+                sendLeaveMembership(room2, room2MembershipData);
+                expect(onEnded).toHaveBeenCalled();
+                onEnded.mockClear();
 
-        try {
-            const room1 = makeMockRoom([{ ...membershipTemplate, application: "m.other" }]);
+                // Stop room1's RTC session. Not tracked.
+                jest.spyOn(client, "getRoom").mockReturnValue(room1);
+                sendLeaveMembership(room1, room1MembershipData);
+                expect(onEnded).not.toHaveBeenCalled();
+            } finally {
+                client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+                client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
+            }
+        });
+
+        it("Doesn't fire event if unrelated sessions ends", () => {
+            const onEnded = jest.fn();
+            client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
+            const membership: MembershipData[] = [{ ...membershipTemplate, application: "m.other_app" }];
+            const room1 = makeMockRoom(membership, eventKind === "sticky");
             jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-
-            client.emit(ClientEvent.Room, room1);
-            expect(onStarted).not.toHaveBeenCalled();
-            onStarted.mockClear();
-
-            const room2 = makeMockRoom([{ ...membershipTemplate, application: "m.notCall", call_id: "test" }]);
-            jest.spyOn(client, "getRooms").mockReturnValue([room1, room2]);
-
-            client.emit(ClientEvent.Room, room2);
-            expect(onStarted).toHaveBeenCalled();
-            onStarted.mockClear();
-
-            mockRoomState(room2, [{ user_id: membershipTemplate.user_id }]);
-            jest.spyOn(client, "getRoom").mockReturnValue(room2);
-
-            const roomState = room2.getLiveTimeline().getState(EventTimeline.FORWARDS)!;
-            const membEvent = roomState.getStateEvents("org.matrix.msc3401.call.member")[0];
-            client.emit(RoomStateEvent.Events, membEvent, roomState, null);
-            expect(onEnded).toHaveBeenCalled();
-            onEnded.mockClear();
-
-            mockRoomState(room1, [{ user_id: membershipTemplate.user_id }]);
             jest.spyOn(client, "getRoom").mockReturnValue(room1);
 
-            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);
-            client.matrixRTC.off(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        }
-    });
+            client.emit(ClientEvent.Room, room1);
 
-    it("Doesn't fire event if unrelated sessions ends", () => {
-        const onEnded = jest.fn();
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionEnded, onEnded);
-        const room1 = makeMockRoom([{ ...membershipTemplate, application: "m.other_app" }]);
-        jest.spyOn(client, "getRooms").mockReturnValue([room1]);
-        jest.spyOn(client, "getRoom").mockReturnValue(room1);
+            sendLeaveMembership(room1, membership);
 
-        client.emit(ClientEvent.Room, room1);
-
-        mockRoomState(room1, [{ user_id: membershipTemplate.user_id }]);
-
-        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));
-    });
-});
+            expect(onEnded).not.toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
+        });
+    },
+);

spec/unit/matrixrtc/MembershipManager.spec.ts

@@ -23,17 +23,17 @@ import {
     MatrixError,
     UnsupportedDelayedEventsEndpointError,
     type Room,
+    MAX_STICKY_DURATION_MS,
 } from "../../../src";
 import {
     MembershipManagerEvent,
     Status,
-    type Focus,
-    type LivekitFocusActive,
+    type Transport,
     type SessionMembershipData,
+    type LivekitFocusSelection,
 } from "../../../src/matrixrtc";
 import { makeMockClient, makeMockRoom, membershipTemplate, mockCallMembership, type MockClient } from "./mocks";
-import { logger } from "../../../src/logger.ts";
-import { MembershipManager } from "../../../src/matrixrtc/MembershipManager.ts";
+import { MembershipManager, StickyEventMembershipManager } from "../../../src/matrixrtc/MembershipManager.ts";
 
 /**
  * Create a promise that will resolve once a mocked method is called.
@@ -76,11 +76,11 @@ const callSession = { id: "", application: "m.call" };
 describe("MembershipManager", () => {
     let client: MockClient;
     let room: Room;
-    const focusActive: LivekitFocusActive = {
+    const focusActive: LivekitFocusSelection = {
         focus_selection: "oldest_membership",
         type: "livekit",
     };
-    const focus: Focus = {
+    const focus: Transport = {
         type: "livekit",
         livekit_service_url: "https://active.url",
         livekit_alias: "!active:active.url",
@@ -94,7 +94,9 @@ 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(() => {
@@ -104,12 +106,12 @@ describe("MembershipManager", () => {
 
     describe("isActivated()", () => {
         it("defaults to false", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             expect(manager.isActivated()).toEqual(false);
         });
 
         it("returns true after join()", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([]);
             expect(manager.isActivated()).toEqual(true);
         });
@@ -123,8 +125,8 @@ describe("MembershipManager", () => {
                 const updateDelayedEventHandle = createAsyncHandle<void>(client._unstable_updateDelayedEvent as Mock);
 
                 // Test
-                const memberManager = new MembershipManager(undefined, room, client, () => undefined, callSession);
-                memberManager.join([focus], focusActive);
+                const memberManager = new MembershipManager(undefined, room, client, callSession);
+                memberManager.join([focus], undefined);
                 // expects
                 await waitForMockCall(client.sendStateEvent, Promise.resolve({ event_id: "id" }));
                 expect(client.sendStateEvent).toHaveBeenCalledWith(
@@ -153,7 +155,7 @@ describe("MembershipManager", () => {
             });
 
             it("reschedules delayed leave event if sending state cancels it", async () => {
-                const memberManager = new MembershipManager(undefined, room, client, () => undefined, callSession);
+                const memberManager = new MembershipManager(undefined, room, client, callSession);
                 const waitForSendState = waitForMockCall(client.sendStateEvent);
                 const waitForUpdateDelaye = waitForMockCallOnce(
                     client._unstable_updateDelayedEvent,
@@ -228,10 +230,9 @@ describe("MembershipManager", () => {
                         },
                         room,
                         client,
-                        () => undefined,
                         callSession,
                     );
-                    manager.join([focus], focusActive);
+                    manager.join([focus]);
 
                     await sendDelayedStateExceedAttempt.then(); // needed to resolve after the send attempt catches
                     await sendDelayedStateAttempt;
@@ -286,8 +287,8 @@ describe("MembershipManager", () => {
         describe("delayed leave event", () => {
             it("does not try again to schedule a delayed leave event if not supported", () => {
                 const delayedHandle = createAsyncHandle(client._unstable_sendDelayedStateEvent as Mock);
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({}, room, client, callSession);
+                manager.join([focus]);
                 delayedHandle.reject?.(
                     new UnsupportedDelayedEventsEndpointError(
                         "Server does not support the delayed events API",
@@ -298,21 +299,15 @@ describe("MembershipManager", () => {
             });
             it("does try to schedule a delayed leave event again if rate limited", async () => {
                 const delayedHandle = createAsyncHandle(client._unstable_sendDelayedStateEvent as Mock);
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({}, room, client, callSession);
+                manager.join([focus]);
                 delayedHandle.reject?.(new HTTPError("rate limited", 429, undefined));
                 await jest.advanceTimersByTimeAsync(5000);
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(2);
             });
             it("uses delayedLeaveEventDelayMs from config", () => {
-                const manager = new MembershipManager(
-                    { delayedLeaveEventDelayMs: 123456 },
-                    room,
-                    client,
-                    () => undefined,
-                    callSession,
-                );
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({ delayedLeaveEventDelayMs: 123456 }, room, client, callSession);
+                manager.join([focus]);
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
                     room.roomId,
                     { delay: 123456 },
@@ -329,11 +324,11 @@ describe("MembershipManager", () => {
                 { delayedLeaveEventRestartMs: RESTART_DELAY },
                 room,
                 client,
-                () => undefined,
+
                 callSession,
             );
             // Join with the membership manager
-            manager.join([focus], focusActive);
+            manager.join([focus]);
             expect(manager.status).toBe(Status.Connecting);
             // Let the scheduler run one iteration so that we can send the join state event
             await jest.runOnlyPendingTimersAsync();
@@ -367,11 +362,11 @@ describe("MembershipManager", () => {
                 { membershipEventExpiryMs: 1234567 },
                 room,
                 client,
-                () => undefined,
+
                 callSession,
             );
 
-            manager.join([focus], focusActive);
+            manager.join([focus]);
             await waitForMockCall(client.sendStateEvent);
             expect(client.sendStateEvent).toHaveBeenCalledWith(
                 room.roomId,
@@ -393,11 +388,11 @@ describe("MembershipManager", () => {
         });
 
         it("does nothing if join called when already joined", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
             await waitForMockCall(client.sendStateEvent);
             expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
-            manager.join([focus], focusActive);
+            manager.join([focus]);
             expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
         });
     });
@@ -405,16 +400,16 @@ describe("MembershipManager", () => {
     describe("leave()", () => {
         // TODO add rate limit cases.
         it("resolves delayed leave event when leave is called", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
             await jest.advanceTimersByTimeAsync(1);
             await manager.leave();
             expect(client._unstable_updateDelayedEvent).toHaveBeenLastCalledWith("id", "send");
             expect(client.sendStateEvent).toHaveBeenCalled();
         });
         it("send leave event when leave is called and resolving delayed leave fails", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
             await jest.advanceTimersByTimeAsync(1);
             (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValue("unknown");
             await manager.leave();
@@ -428,60 +423,16 @@ describe("MembershipManager", () => {
             );
         });
         it("does nothing if not joined", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             expect(async () => await manager.leave()).not.toThrow();
             expect(client._unstable_sendDelayedStateEvent).not.toHaveBeenCalled();
             expect(client.sendStateEvent).not.toHaveBeenCalled();
         });
     });
 
-    describe("getsActiveFocus", () => {
-        it("gets the correct active focus with oldest_membership", () => {
-            const getOldestMembership = jest.fn();
-            const manager = new MembershipManager({}, room, client, getOldestMembership, callSession);
-            // Before joining the active focus should be undefined (see FocusInUse on MatrixRTCSession)
-            expect(manager.getActiveFocus()).toBe(undefined);
-            manager.join([focus], focusActive);
-            // After joining we want our own focus to be the one we select.
-            getOldestMembership.mockReturnValue(
-                mockCallMembership(
-                    {
-                        ...membershipTemplate,
-                        foci_preferred: [
-                            {
-                                livekit_alias: "!active:active.url",
-                                livekit_service_url: "https://active.url",
-                                type: "livekit",
-                            },
-                        ],
-                        user_id: client.getUserId()!,
-                        device_id: client.getDeviceId()!,
-                        created_ts: 1000,
-                    },
-                    room.roomId,
-                ),
-            );
-            expect(manager.getActiveFocus()).toStrictEqual(focus);
-            getOldestMembership.mockReturnValue(
-                mockCallMembership(
-                    Object.assign({}, membershipTemplate, { device_id: "old", created_ts: 1000 }),
-                    room.roomId,
-                ),
-            );
-            // If there is an older member we use its focus.
-            expect(manager.getActiveFocus()).toBe(membershipTemplate.foci_preferred[0]);
-        });
-
-        it("does not provide focus if the selection method is unknown", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
-            manager.join([focus], Object.assign(focusActive, { type: "unknown_type" }));
-            expect(manager.getActiveFocus()).toBe(undefined);
-        });
-    });
-
     describe("onRTCSessionMemberUpdate()", () => {
         it("does nothing if not joined", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             await manager.onRTCSessionMemberUpdate([mockCallMembership(membershipTemplate, room.roomId)]);
             await jest.advanceTimersToNextTimerAsync();
             expect(client.sendStateEvent).not.toHaveBeenCalled();
@@ -489,7 +440,7 @@ describe("MembershipManager", () => {
             expect(client._unstable_updateDelayedEvent).not.toHaveBeenCalled();
         });
         it("does nothing if own membership still present", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive);
             await jest.advanceTimersByTimeAsync(1);
             const myMembership = (client.sendStateEvent as Mock).mock.calls[0][2];
@@ -513,7 +464,7 @@ describe("MembershipManager", () => {
             expect(client._unstable_updateDelayedEvent).not.toHaveBeenCalled();
         });
         it("recreates membership if it is missing", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive);
             await jest.advanceTimersByTimeAsync(1);
             // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
@@ -531,7 +482,7 @@ describe("MembershipManager", () => {
         });
 
         it("updates the UpdateExpiry entry in the action scheduler", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive);
             await jest.advanceTimersByTimeAsync(1);
             // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
@@ -564,7 +515,6 @@ describe("MembershipManager", () => {
                 { delayedLeaveEventRestartMs: 10_000, delayedLeaveEventDelayMs: 30_000 },
                 room,
                 client,
-                () => undefined,
                 { id: "", application: "m.call" },
             );
             manager.join([focus], focusActive);
@@ -596,7 +546,7 @@ describe("MembershipManager", () => {
                 { membershipEventExpiryMs: expire, membershipEventExpiryHeadroomMs: headroom },
                 room,
                 client,
-                () => undefined,
+
                 { id: "", application: "m.call" },
             );
             manager.join([focus], focusActive);
@@ -621,14 +571,14 @@ describe("MembershipManager", () => {
 
     describe("status updates", () => {
         it("starts 'Disconnected'", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             expect(manager.status).toBe(Status.Disconnected);
         });
         it("emits 'Connection' and 'Connected' after join", async () => {
             const handleDelayedEvent = createAsyncHandle<void>(client._unstable_sendDelayedStateEvent);
             const handleStateEvent = createAsyncHandle<void>(client.sendStateEvent);
 
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             expect(manager.status).toBe(Status.Disconnected);
             const connectEmit = jest.fn();
             manager.on(MembershipManagerEvent.StatusChanged, connectEmit);
@@ -642,7 +592,7 @@ describe("MembershipManager", () => {
             expect(connectEmit).toHaveBeenCalledWith(Status.Connecting, Status.Connected);
         });
         it("emits 'Disconnecting' and 'Disconnected' after leave", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             const connectEmit = jest.fn();
             manager.on(MembershipManagerEvent.StatusChanged, connectEmit);
             manager.join([focus], focusActive);
@@ -658,7 +608,7 @@ describe("MembershipManager", () => {
             it("sends retry if call membership event is still valid at time of retry", async () => {
                 const handle = createAsyncHandle(client._unstable_sendDelayedStateEvent);
 
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+                const manager = new MembershipManager({}, room, client, callSession);
                 manager.join([focus], focusActive);
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
 
@@ -685,7 +635,7 @@ describe("MembershipManager", () => {
                         new Headers({ "Retry-After": "1" }),
                     ),
                 );
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+                const manager = new MembershipManager({}, room, client, callSession);
                 // Should call _unstable_sendDelayedStateEvent but not sendStateEvent because of the
                 // RateLimit error.
                 manager.join([focus], focusActive);
@@ -705,7 +655,7 @@ describe("MembershipManager", () => {
             it("abandons retry loop if leave() was called before sending state event", async () => {
                 const handle = createAsyncHandle(client._unstable_sendDelayedStateEvent);
 
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+                const manager = new MembershipManager({}, room, client, callSession);
                 manager.join([focus], focusActive);
                 handle.reject?.(
                     new MatrixError(
@@ -740,7 +690,7 @@ describe("MembershipManager", () => {
                         new Headers({ "Retry-After": "1" }),
                     ),
                 );
-                const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+                const manager = new MembershipManager({}, room, client, callSession);
                 manager.join([focus], focusActive);
 
                 // Hit rate limit
@@ -773,7 +723,7 @@ describe("MembershipManager", () => {
                     new Headers({ "Retry-After": "2" }),
                 ),
             );
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive, delayEventSendError);
 
             for (let i = 0; i < 10; i++) {
@@ -793,7 +743,7 @@ describe("MembershipManager", () => {
                     new Headers({ "Retry-After": "1" }),
                 ),
             );
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive, delayEventRestartError);
 
             for (let i = 0; i < 10; i++) {
@@ -804,7 +754,7 @@ describe("MembershipManager", () => {
         it("falls back to using pure state events when some error occurs while sending delayed events", async () => {
             const unrecoverableError = jest.fn();
             (client._unstable_sendDelayedStateEvent as Mock<any>).mockRejectedValue(new HTTPError("unknown", 601));
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive, unrecoverableError);
             await waitForMockCall(client.sendStateEvent);
             expect(unrecoverableError).not.toHaveBeenCalledWith();
@@ -817,7 +767,6 @@ describe("MembershipManager", () => {
                 { networkErrorRetryMs: 1000, maximumNetworkErrorRetryCount: 7 },
                 room,
                 client,
-                () => undefined,
                 callSession,
             );
             manager.join([focus], focusActive, unrecoverableError);
@@ -836,7 +785,7 @@ describe("MembershipManager", () => {
             (client._unstable_sendDelayedStateEvent as Mock<any>).mockRejectedValue(
                 new UnsupportedDelayedEventsEndpointError("not supported", "sendDelayedStateEvent"),
             );
-            const manager = new MembershipManager({}, room, client, () => undefined, callSession);
+            const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus], focusActive, unrecoverableError);
             await jest.advanceTimersByTimeAsync(1);
 
@@ -850,7 +799,7 @@ describe("MembershipManager", () => {
                 { delayedLeaveEventDelayMs: 10000 },
                 room,
                 client,
-                () => undefined,
+
                 callSession,
             );
             const { promise: stuckPromise, reject: rejectStuckPromise } = Promise.withResolvers<EmptyObject>();
@@ -901,13 +850,107 @@ describe("MembershipManager", () => {
             }
         });
     });
+
+    describe("updateCallIntent()", () => {
+        it("should fail if the user has not joined the call", async () => {
+            const manager = new MembershipManager({}, room, client, callSession);
+            // After joining we want our own focus to be the one we select.
+            try {
+                await manager.updateCallIntent("video");
+                throw Error("Should have thrown");
+            } catch {}
+        });
+
+        it("can adjust the intent", async () => {
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([]);
+            expect(manager.isActivated()).toEqual(true);
+            const membership = mockCallMembership({ ...membershipTemplate, user_id: client.getUserId()! }, room.roomId);
+            await manager.onRTCSessionMemberUpdate([membership]);
+            await manager.updateCallIntent("video");
+            expect(client.sendStateEvent).toHaveBeenCalledTimes(2);
+            const eventContent = (client.sendStateEvent as Mock).mock.calls[0][2] as SessionMembershipData;
+            expect(eventContent["created_ts"]).toEqual(membership.createdTs());
+            expect(eventContent["m.call.intent"]).toEqual("video");
+        });
+
+        it("does nothing if the intent doesn't change", async () => {
+            const manager = new MembershipManager({ callIntent: "video" }, room, client, callSession);
+            manager.join([]);
+            expect(manager.isActivated()).toEqual(true);
+            const membership = mockCallMembership(
+                { ...membershipTemplate, "user_id": client.getUserId()!, "m.call.intent": "video" },
+                room.roomId,
+            );
+            await manager.onRTCSessionMemberUpdate([membership]);
+            await manager.updateCallIntent("video");
+            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", () => {
     const client = makeMockClient("@alice:example.org", "AAAAAAA");
     const room = makeMockRoom([membershipTemplate]);
 
-    const membershipManager = new MembershipManager(undefined, room, client, () => undefined, callSession, logger);
+    const membershipManager = new MembershipManager(undefined, room, client, callSession);
 
     const spy = jest.spyOn(console, "error");
     // Double join

spec/unit/matrixrtc/RTCEncryptionManager.spec.ts

@@ -22,9 +22,7 @@ import { type ToDeviceKeyTransport } from "../../../src/matrixrtc/ToDeviceKeyTra
 import { KeyTransportEvents, type KeyTransportEventsHandlerMap } from "../../../src/matrixrtc/IKeyTransport.ts";
 import { membershipTemplate, mockCallMembership } from "./mocks.ts";
 import { decodeBase64, TypedEventEmitter } from "../../../src";
-import { RoomAndToDeviceTransport } from "../../../src/matrixrtc/RoomAndToDeviceKeyTransport.ts";
-import { type RoomKeyTransport } from "../../../src/matrixrtc/RoomKeyTransport.ts";
-import { logger, type Logger } from "../../../src/logger.ts";
+import { logger } from "../../../src/logger.ts";
 import { getParticipantId } from "../../../src/matrixrtc/utils.ts";
 
 describe("RTCEncryptionManager", () => {
@@ -782,86 +780,6 @@ describe("RTCEncryptionManager", () => {
         );
     });
 
-    it("Should re-distribute key on transport switch", async () => {
-        const toDeviceEmitter = new TypedEventEmitter<KeyTransportEvents, KeyTransportEventsHandlerMap>();
-        const mockToDeviceTransport = {
-            start: jest.fn(),
-            stop: jest.fn(),
-            sendKey: jest.fn().mockResolvedValue(undefined),
-            on: toDeviceEmitter.on.bind(toDeviceEmitter),
-            off: toDeviceEmitter.off.bind(toDeviceEmitter),
-            emit: toDeviceEmitter.emit.bind(toDeviceEmitter),
-            setParentLogger: jest.fn(),
-        } as unknown as Mocked<ToDeviceKeyTransport>;
-
-        const roomEmitter = new TypedEventEmitter<KeyTransportEvents, KeyTransportEventsHandlerMap>();
-        const mockRoomTransport = {
-            start: jest.fn(),
-            stop: jest.fn(),
-            sendKey: jest.fn().mockResolvedValue(undefined),
-            on: roomEmitter.on.bind(roomEmitter),
-            off: roomEmitter.off.bind(roomEmitter),
-            emit: roomEmitter.emit.bind(roomEmitter),
-            setParentLogger: jest.fn(),
-        } as unknown as Mocked<RoomKeyTransport>;
-
-        const mockLogger = {
-            debug: jest.fn(),
-            warn: jest.fn(),
-        } as unknown as Mocked<Logger>;
-
-        const transport = new RoomAndToDeviceTransport(mockToDeviceTransport, mockRoomTransport, {
-            getChild: jest.fn().mockReturnValue(mockLogger),
-        } as unknown as Mocked<Logger>);
-
-        encryptionManager = new RTCEncryptionManager(
-            "@alice:example.org",
-            "DEVICE01",
-            getMembershipMock,
-            transport,
-            statistics,
-            onEncryptionKeysChanged,
-        );
-
-        const members = [
-            aCallMembership("@bob:example.org", "BOBDEVICE"),
-            aCallMembership("@bob:example.org", "BOBDEVICE2"),
-            aCallMembership("@carl:example.org", "CARLDEVICE"),
-        ];
-        getMembershipMock.mockReturnValue(members);
-
-        // Let's join
-        encryptionManager.join(undefined);
-        encryptionManager.onMembershipsUpdate();
-        await jest.advanceTimersByTimeAsync(10);
-
-        // Should have sent the key to the toDevice transport
-        expect(mockToDeviceTransport.sendKey).toHaveBeenCalledTimes(1);
-        expect(mockRoomTransport.sendKey).not.toHaveBeenCalled();
-
-        // Simulate receiving a key by room transport
-        roomEmitter.emit(
-            KeyTransportEvents.ReceivedKeys,
-            "@bob:example.org",
-            "BOBDEVICE",
-            "AAAAAAAAAAA",
-            0 /* KeyId */,
-            0 /* Timestamp */,
-        );
-
-        await jest.runOnlyPendingTimersAsync();
-
-        // The key should have been re-distributed to the room transport
-        expect(mockRoomTransport.sendKey).toHaveBeenCalled();
-        expect(mockToDeviceTransport.sendKey).toHaveBeenCalledWith(
-            expect.any(String),
-            // It is the first key re-distributed
-            0,
-            // to all the members
-            members.map((m) => ({ userId: m.sender, deviceId: m.deviceId, membershipTs: m.createdTs() })),
-        );
-    });
-
     function aCallMembership(userId: string, deviceId: string, ts: number = 1000): CallMembership {
         return mockCallMembership(
             { ...membershipTemplate, user_id: userId, device_id: deviceId, created_ts: ts },

spec/unit/matrixrtc/RoomAndToDeviceTransport.spec.ts

@@ -1,187 +0,0 @@
-/*
-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 Mocked } from "jest-mock";
-
-import { makeKey, makeMockEvent, makeMockRoom } from "./mocks";
-import { EventType, type IRoomTimelineData, type Room, RoomEvent, type MatrixClient } from "../../../src";
-import { ToDeviceKeyTransport } from "../../../src/matrixrtc/ToDeviceKeyTransport.ts";
-import {
-    getMockClientWithEventEmitter,
-    mockClientMethodsEvents,
-    mockClientMethodsUser,
-} from "../../test-utils/client.ts";
-import { type ParticipantDeviceInfo, type Statistics } from "../../../src/matrixrtc";
-import { KeyTransportEvents } from "../../../src/matrixrtc/IKeyTransport.ts";
-import { type Logger } from "../../../src/logger.ts";
-import { RoomAndToDeviceEvents, RoomAndToDeviceTransport } from "../../../src/matrixrtc/RoomAndToDeviceKeyTransport.ts";
-import { RoomKeyTransport } from "../../../src/matrixrtc/RoomKeyTransport.ts";
-
-describe("RoomAndToDeviceTransport", () => {
-    const roomId = "!room:id";
-
-    let mockClient: Mocked<MatrixClient>;
-    let statistics: Statistics;
-    let mockLogger: Mocked<Logger>;
-    let transport: RoomAndToDeviceTransport;
-    let mockRoom: Room;
-    let sendEventMock: jest.Mock;
-    let roomKeyTransport: RoomKeyTransport;
-    let toDeviceKeyTransport: ToDeviceKeyTransport;
-    let toDeviceSendKeySpy: jest.SpyInstance;
-    let roomSendKeySpy: jest.SpyInstance;
-    beforeEach(() => {
-        sendEventMock = jest.fn();
-        mockClient = getMockClientWithEventEmitter({
-            encryptAndSendToDevice: jest.fn(),
-            getDeviceId: jest.fn().mockReturnValue("MYDEVICE"),
-            ...mockClientMethodsEvents(),
-            ...mockClientMethodsUser("@alice:example.org"),
-            sendEvent: sendEventMock,
-        });
-        mockRoom = makeMockRoom([]);
-        mockLogger = {
-            debug: jest.fn(),
-            warn: jest.fn(),
-            getChild: jest.fn(),
-        } as unknown as Mocked<Logger>;
-        mockLogger.getChild.mockReturnValue(mockLogger);
-        statistics = {
-            counters: {
-                roomEventEncryptionKeysSent: 0,
-                roomEventEncryptionKeysReceived: 0,
-            },
-            totals: {
-                roomEventEncryptionKeysReceivedTotalAge: 0,
-            },
-        };
-        roomKeyTransport = new RoomKeyTransport(mockRoom, mockClient, statistics);
-        toDeviceKeyTransport = new ToDeviceKeyTransport(
-            "@alice:example.org",
-            "MYDEVICE",
-            mockRoom.roomId,
-            mockClient,
-            statistics,
-        );
-        transport = new RoomAndToDeviceTransport(toDeviceKeyTransport, roomKeyTransport, mockLogger);
-        toDeviceSendKeySpy = jest.spyOn(toDeviceKeyTransport, "sendKey");
-        roomSendKeySpy = jest.spyOn(roomKeyTransport, "sendKey");
-    });
-
-    it("should enable to device transport when starting", () => {
-        transport.start();
-        expect(transport.enabled.room).toBeFalsy();
-        expect(transport.enabled.toDevice).toBeTruthy();
-    });
-    it("only sends to device keys when sending a key", async () => {
-        transport.start();
-        await transport.sendKey("1235", 0, [
-            { userId: "@alice:example.org", deviceId: "ALICEDEVICE", membershipTs: 1234 },
-        ]);
-        expect(toDeviceSendKeySpy).toHaveBeenCalledTimes(1);
-        expect(roomSendKeySpy).toHaveBeenCalledTimes(0);
-        expect(transport.enabled.room).toBeFalsy();
-        expect(transport.enabled.toDevice).toBeTruthy();
-    });
-
-    it("enables room transport and disables to device transport when receiving a room key", async () => {
-        transport.start();
-        const onNewKeyFromTransport = jest.fn();
-        const onTransportEnabled = jest.fn();
-        transport.on(KeyTransportEvents.ReceivedKeys, onNewKeyFromTransport);
-        transport.on(RoomAndToDeviceEvents.EnabledTransportsChanged, onTransportEnabled);
-        mockRoom.emit(
-            RoomEvent.Timeline,
-            makeMockEvent(EventType.CallEncryptionKeysPrefix, "@bob:example.org", roomId, {
-                call_id: "",
-                keys: [makeKey(0, "testKey")],
-                sent_ts: Date.now(),
-                device_id: "AAAAAAA",
-            }),
-            undefined,
-            undefined,
-            false,
-            {} as IRoomTimelineData,
-        );
-        await jest.advanceTimersByTimeAsync(1);
-        expect(transport.enabled.room).toBeTruthy();
-        expect(transport.enabled.toDevice).toBeFalsy();
-
-        await transport.sendKey("1235", 0, [
-            { userId: "@alice:example.org", deviceId: "AlICEDEV", membershipTs: 1234 },
-        ]);
-        expect(sendEventMock).toHaveBeenCalledTimes(1);
-        expect(roomSendKeySpy).toHaveBeenCalledTimes(1);
-        expect(toDeviceSendKeySpy).toHaveBeenCalledTimes(0);
-        expect(onTransportEnabled).toHaveBeenCalledWith({ toDevice: false, room: true });
-    });
-
-    it("enables room transport and disables to device transport on widget driver error", async () => {
-        mockClient.encryptAndSendToDevice.mockRejectedValue({
-            message:
-                "unknown variant `send_to_device`, expected one of `supported_api_versions`, `content_loaded`, `get_openid`, `org.matrix.msc2876.read_events`, `send_event`, `org.matrix.msc4157.update_delayed_event` at line 1 column 22",
-        });
-
-        transport.start();
-        const membership: ParticipantDeviceInfo = {
-            userId: "@alice:example.org",
-            deviceId: "ALICEDEVICE",
-            membershipTs: 1234,
-        };
-        const onTransportEnabled = jest.fn();
-        transport.on(RoomAndToDeviceEvents.EnabledTransportsChanged, onTransportEnabled);
-
-        // We start with toDevice transport enabled
-        expect(transport.enabled.room).toBeFalsy();
-        expect(transport.enabled.toDevice).toBeTruthy();
-
-        await transport.sendKey("1235", 0, [membership]);
-
-        // We switched transport, now room transport is enabled
-        expect(onTransportEnabled).toHaveBeenCalledWith({ toDevice: false, room: true });
-        expect(transport.enabled.room).toBeTruthy();
-        expect(transport.enabled.toDevice).toBeFalsy();
-
-        // sanity check that we called the failang to device send key.
-        expect(toDeviceKeyTransport.sendKey).toHaveBeenCalledWith("1235", 0, [membership]);
-        expect(toDeviceKeyTransport.sendKey).toHaveBeenCalledTimes(1);
-        // We re-sent the key via the room transport
-        expect(roomKeyTransport.sendKey).toHaveBeenCalledWith("1235", 0, [membership]);
-        expect(roomKeyTransport.sendKey).toHaveBeenCalledTimes(1);
-
-        mockClient.encryptAndSendToDevice.mockRestore();
-    });
-
-    it("does log that it did nothing when disabled", () => {
-        transport.start();
-        const onNewKeyFromTransport = jest.fn();
-        const onTransportEnabled = jest.fn();
-        transport.on(KeyTransportEvents.ReceivedKeys, onNewKeyFromTransport);
-        transport.on(RoomAndToDeviceEvents.EnabledTransportsChanged, onTransportEnabled);
-
-        transport.setEnabled({ toDevice: false, room: false });
-        const dateNow = Date.now();
-        roomKeyTransport.emit(KeyTransportEvents.ReceivedKeys, "user", "device", "roomKey", 0, dateNow);
-        toDeviceKeyTransport.emit(KeyTransportEvents.ReceivedKeys, "user", "device", "toDeviceKey", 0, Date.now());
-
-        expect(mockLogger.debug).toHaveBeenCalledWith("To Device transport is disabled, ignoring received keys");
-        // for room key transport we will never get a disabled message because its will always just turn on
-        expect(onTransportEnabled).toHaveBeenNthCalledWith(1, { toDevice: false, room: false });
-        expect(onTransportEnabled).toHaveBeenNthCalledWith(2, { toDevice: false, room: true });
-        expect(onNewKeyFromTransport).toHaveBeenCalledTimes(1);
-        expect(onNewKeyFromTransport).toHaveBeenCalledWith("user", "device", "roomKey", 0, dateNow);
-    });
-});

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, type Room, RoomEvent, type MatrixClient, type MatrixEvent } from "../../../src";
 import { CallMembership, type SessionMembershipData } from "../../../src/matrixrtc/CallMembership";
@@ -51,6 +52,8 @@ export type MockClient = Pick<
     | "sendStateEvent"
     | "_unstable_sendDelayedStateEvent"
     | "_unstable_updateDelayedEvent"
+    | "_unstable_sendStickyEvent"
+    | "_unstable_sendStickyDelayedEvent"
     | "cancelPendingEvent"
 >;
 /**
@@ -65,15 +68,19 @@ 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),
@@ -81,11 +88,16 @@ 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,
+    });
     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) {
@@ -129,6 +141,7 @@ export function makeMockEvent(
     roomId: string | undefined,
     content: any,
     timestamp?: number,
+    stateKey?: string,
 ): MatrixEvent {
     return {
         getType: jest.fn().mockReturnValue(type),
@@ -137,12 +150,28 @@ export function makeMockEvent(
         getTs: jest.fn().mockReturnValue(timestamp ?? Date.now()),
         getRoomId: jest.fn().mockReturnValue(roomId),
         getId: jest.fn().mockReturnValue(secureRandomString(8)),
+        getStateKey: jest.fn().mockReturnValue(stateKey),
         isDecryptionFailure: jest.fn().mockReturnValue(false),
     } as unknown as MatrixEvent;
 }
 
-export function mockRTCEvent({ user_id: sender, ...membershipData }: MembershipData, roomId: string): MatrixEvent {
-    return makeMockEvent(EventType.GroupCallMemberPrefix, sender, roomId, membershipData);
+export function mockRTCEvent(
+    { 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/event.spec.ts

@@ -16,10 +16,11 @@ limitations under the License.
 
 import { type MockedObject } from "jest-mock";
 
-import { MatrixEvent, MatrixEventEvent } from "../../../src/models/event";
+import { type IContent, MatrixEvent, MatrixEventEvent } from "../../../src/models/event";
 import { emitPromise } from "../../test-utils/test-utils";
 import {
     type IAnnotatedPushRule,
+    type IStickyEvent,
     type MatrixClient,
     PushRuleActionName,
     Room,
@@ -335,6 +336,31 @@ describe("MatrixEvent", () => {
         }
     });
 
+    describe("state key packing", () => {
+        it("should pack the state key during encryption", () => {
+            const ev = createStateEvent("$event1:server", "m.room.topic", "", { topic: "" });
+            expect(ev.getStateKey()).toStrictEqual("");
+            ev.makeEncrypted("m.room.encrypted", { ciphertext: "xyz" }, "", "");
+            expect(ev.getStateKey()).toStrictEqual("");
+            expect(ev.getWireStateKey()).toStrictEqual("m.room.topic:");
+
+            const keyedEv = createStateEvent("$event2:server", "m.beacon_info", "@alice:server", {});
+            expect(keyedEv.getStateKey()).toStrictEqual("@alice:server");
+            keyedEv.makeEncrypted("m.room.encrypted", { ciphertext: "xyz" }, "", "");
+            expect(keyedEv.getStateKey()).toStrictEqual("@alice:server");
+            expect(keyedEv.getWireStateKey()).toStrictEqual("m.beacon_info:@alice:server");
+        });
+
+        function createStateEvent(eventId: string, type: string, stateKey: string, content?: IContent): MatrixEvent {
+            return new MatrixEvent({
+                type,
+                state_key: stateKey,
+                content,
+                event_id: eventId,
+            });
+        }
+    });
+
     describe("applyVisibilityEvent", () => {
         it("should emit VisibilityChange if a change was made", async () => {
             const ev = new MatrixEvent({
@@ -573,6 +599,39 @@ describe("MatrixEvent", () => {
         expect(stateEvent.isState()).toBeTruthy();
         expect(stateEvent.threadRootId).toBeUndefined();
     });
+
+    it("should calculate sticky duration correctly", async () => {
+        const evData: IStickyEvent = {
+            event_id: "$event_id",
+            type: "some_state_event",
+            content: {},
+            sender: "@alice:example.org",
+            origin_server_ts: 50,
+            msc4354_sticky: {
+                duration_ms: 1000,
+            },
+            unsigned: {
+                msc4354_sticky_duration_ttl_ms: 5000,
+            },
+        };
+        try {
+            jest.useFakeTimers();
+            jest.setSystemTime(50);
+            // Prefer unsigned
+            expect(new MatrixEvent({ ...evData } satisfies IStickyEvent).unstableStickyExpiresAt).toEqual(5050);
+            // Fall back to `duration_ms`
+            expect(
+                new MatrixEvent({ ...evData, unsigned: undefined } satisfies IStickyEvent).unstableStickyExpiresAt,
+            ).toEqual(1050);
+            // Prefer current time if `origin_server_ts` is more recent.
+            expect(
+                new MatrixEvent({ ...evData, unsigned: undefined, origin_server_ts: 5000 } satisfies IStickyEvent)
+                    .unstableStickyExpiresAt,
+            ).toEqual(1050);
+        } finally {
+            jest.useRealTimers();
+        }
+    });
 });
 
 function mainTimelineLiveEventIds(room: Room): Array<string> {

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

@@ -0,0 +1,422 @@
+import { type IStickyEvent, MatrixEvent } from "../../../src";
+import { RoomStickyEventsStore, RoomStickyEventsEvent } from "../../../src/models/room-sticky-events";
+
+describe("RoomStickyEvents", () => {
+    let stickyEvents: RoomStickyEventsStore;
+    const emitSpy: jest.Mock = jest.fn();
+    const stickyEvent: IStickyEvent = {
+        event_id: "$foo:bar",
+        room_id: "!roomId",
+        type: "org.example.any_type",
+        msc4354_sticky: {
+            duration_ms: 15000,
+        },
+        content: {
+            msc4354_sticky_key: "foobar",
+        },
+        sender: "@alice:example.org",
+        origin_server_ts: Date.now(),
+        unsigned: {},
+    };
+
+    beforeEach(() => {
+        emitSpy.mockReset();
+        stickyEvents = new RoomStickyEventsStore();
+        stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+    });
+
+    afterEach(() => {
+        stickyEvents?.clear();
+    });
+
+    describe("addStickyEvents", () => {
+        it("should allow adding an event without a msc4354_sticky_key", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, content: {} })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(1);
+        });
+        it("should not allow adding an event without a msc4354_sticky property", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, msc4354_sticky: undefined })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({ ...stickyEvent, msc4354_sticky: { duration_ms: undefined } as any }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should not allow adding an event without a sender", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, sender: undefined })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should not allow adding an event with an invalid sender", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, sender: "not_a_real_sender" })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should ignore old events", () => {
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({ ...stickyEvent, origin_server_ts: 0, msc4354_sticky: { duration_ms: 1 } }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should be able to just add an event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should not replace events on ID tie break", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({
+                    ...stickyEvent,
+                    event_id: "$abc:bar",
+                }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should not replace a newer event with an older event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({
+                    ...stickyEvent,
+                    origin_server_ts: 1,
+                }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should replace an older event with a newer event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent, event_id: "$old" });
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$new",
+                origin_server_ts: Date.now() + 2000,
+            });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([newerEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([newerEv]);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: newerEv, previous: originalEv }], []);
+        });
+        it("should allow multiple events with the same sticky key for different event types", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            const anotherEv = new MatrixEvent({
+                ...stickyEvent,
+                type: "org.example.another_type",
+            });
+            stickyEvents.addStickyEvents([originalEv, anotherEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv, anotherEv]);
+        });
+
+        it("should emit when a new sticky event is added", () => {
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+            expect(emitSpy).toHaveBeenCalledWith([ev], [], []);
+        });
+        it("should emit when a new unkeyed sticky event is added", () => {
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+            expect(emitSpy).toHaveBeenCalledWith([ev], [], []);
+        });
+    });
+
+    describe("getStickyEvents", () => {
+        it("should have zero sticky events", () => {
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should contain a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+        });
+        it("should contain two sticky events", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            const ev2 = new MatrixEvent({
+                ...stickyEvent,
+                sender: "@fibble:bobble",
+                content: {
+                    msc4354_sticky_key: "bibble",
+                },
+            });
+            stickyEvents.addStickyEvents([ev, ev2]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev, ev2]);
+        });
+    });
+
+    describe("getKeyedStickyEvent", () => {
+        it("should have zero sticky events", () => {
+            expect(
+                stickyEvents.getKeyedStickyEvent(
+                    stickyEvent.sender,
+                    stickyEvent.type,
+                    stickyEvent.content.msc4354_sticky_key!,
+                ),
+            ).toBeUndefined();
+        });
+        it("should return a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect(
+                stickyEvents.getKeyedStickyEvent(
+                    stickyEvent.sender,
+                    stickyEvent.type,
+                    stickyEvent.content.msc4354_sticky_key!,
+                ),
+            ).toEqual(ev);
+        });
+    });
+
+    describe("getUnkeyedStickyEvent", () => {
+        it("should have zero sticky events", () => {
+            expect(stickyEvents.getUnkeyedStickyEvent(stickyEvent.sender, stickyEvent.type)).toEqual([]);
+        });
+        it("should return a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {
+                    msc4354_sticky_key: undefined,
+                },
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect(stickyEvents.getUnkeyedStickyEvent(stickyEvent.sender, stickyEvent.type)).toEqual([ev]);
+        });
+    });
+
+    describe("cleanExpiredStickyEvents", () => {
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+
+        it("should emit when a sticky event expires", () => {
+            jest.setSystemTime(1000);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: 0,
+            });
+            const evLater = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$baz:bar",
+                sender: "@bob:example.org",
+                origin_server_ts: 1000,
+            });
+            stickyEvents.addStickyEvents([ev, evLater]);
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.advanceTimersByTime(15000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+            // Then expire the next event
+            jest.advanceTimersByTime(1000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [evLater]);
+        });
+        it("should emit two events when both expire at the same time", () => {
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.setSystemTime(0);
+            const ev1 = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$eventA",
+                origin_server_ts: 0,
+            });
+            const ev2 = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$eventB",
+                content: {
+                    msc4354_sticky_key: "key_2",
+                },
+                origin_server_ts: 0,
+            });
+            stickyEvents.addStickyEvents([ev1, ev2]);
+            expect(emitSpy).toHaveBeenCalledWith([ev1, ev2], [], []);
+            jest.advanceTimersByTime(15000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev1, ev2]);
+        });
+        it("should emit when a unkeyed sticky event expires", () => {
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.setSystemTime(0);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            jest.advanceTimersByTime(15000);
+            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/RoomEncryptor.spec.ts

@@ -72,6 +72,7 @@ describe("RoomEncryptor", () => {
                     body: text,
                     msgtype: "m.text",
                 }),
+                isState: () => false,
                 makeEncrypted: jest.fn().mockReturnValue(undefined),
             } as unknown as Mocked<MatrixEvent>;
         }

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

@@ -830,6 +830,7 @@ describe("RustCrypto", () => {
                 TEST_DEVICE_ID,
                 secretStorage,
                 {} as CryptoCallbacks,
+                false,
             );
 
             async function createSecretStorageKey() {
@@ -853,9 +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);
@@ -2418,6 +2437,135 @@ describe("RustCrypto", () => {
             expect(mockOlmMachine.receiveRoomKeyBundle.mock.calls[0][1]).toEqual(new TextEncoder().encode("asdfghjkl"));
         });
     });
+
+    describe("Verification requests", () => {
+        it("fetches device details before room verification requests", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a room verification request
+            const event = mockedEvent("!r:s.co", "@u:s.co", "m.room.message", "m.key.verification.request");
+            await rustCrypto.onLiveEventFromSync(event);
+
+            // Then we first fetch device details
+            expect(outgoingRequestProcessor.makeOutgoingRequest).toHaveBeenCalled();
+
+            // And we handle the verification event as normal
+            expect(olmMachine.receiveVerificationEvent).toHaveBeenCalled();
+        });
+
+        it("does not fetch device details before other verification events", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive some verification event that is not a room request
+            const event = mockedEvent("!r:s.co", "@u:s.co", "m.key.verification.start");
+            await rustCrypto.onLiveEventFromSync(event);
+
+            // Then we do not fetch device details
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+
+            // And we handle the verification event as normal
+            expect(olmMachine.receiveVerificationEvent).toHaveBeenCalled();
+        });
+
+        it("throws an error if sender is missing", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a verification event without a sender
+            // Then we throw
+            const event = mockedEvent("!r:s.co", null, "m.key.verification.start");
+
+            await expect(async () => await rustCrypto.onLiveEventFromSync(event)).rejects.toThrow(
+                "missing sender in the event",
+            );
+
+            // And we do not fetch device details or handle the event
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+            expect(olmMachine.receiveVerificationEvent).not.toHaveBeenCalled();
+        });
+
+        it("throws an error if room is missing", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a verification event without a sender
+            // Then we throw
+            const event = mockedEvent(null, "@u:s.co", "m.key.verification.start");
+
+            await expect(async () => await rustCrypto.onLiveEventFromSync(event)).rejects.toThrow(
+                "missing roomId in the event",
+            );
+
+            // And we do not fetch device details or handle the event
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+            expect(olmMachine.receiveVerificationEvent).not.toHaveBeenCalled();
+        });
+
+        function mockedOlmMachine(): Mocked<OlmMachine> {
+            return {
+                queryKeysForUsers: jest.fn(),
+                getVerificationRequest: jest.fn(),
+                receiveVerificationEvent: jest.fn(),
+            } as unknown as Mocked<OlmMachine>;
+        }
+
+        function makeRustCrypto(
+            olmMachine: OlmMachine,
+            outgoingRequestProcessor: OutgoingRequestProcessor,
+        ): RustCrypto {
+            const rustCrypto = new RustCrypto(
+                new DebugLogger(debug("test Verification requests")),
+                olmMachine,
+                {} as unknown as MatrixHttpApi<IHttpOpts & { onlyData: true }>,
+                TEST_USER,
+                TEST_DEVICE_ID,
+                {} as ServerSideSecretStorage,
+                {} as CryptoCallbacks,
+            );
+
+            // @ts-ignore mocking outgoingRequestProcessor
+            rustCrypto.outgoingRequestProcessor = outgoingRequestProcessor;
+
+            return rustCrypto;
+        }
+
+        function mockedOutgoingRequestProcessor(): OutgoingRequestProcessor {
+            return {
+                makeOutgoingRequest: jest.fn(),
+            } as unknown as Mocked<OutgoingRequestProcessor>;
+        }
+
+        function mockedEvent(
+            roomId: string | null,
+            senderId: string | null,
+            eventType: string,
+            msgtype?: string | undefined,
+        ): MatrixEvent {
+            return {
+                isState: jest.fn().mockReturnValue(false),
+                getUnsigned: jest.fn().mockReturnValue({}),
+                isDecryptionFailure: jest.fn(),
+                isEncrypted: jest.fn(),
+                getType: jest.fn().mockReturnValue(eventType),
+                getRoomId: jest.fn().mockReturnValue(roomId),
+                getSender: jest.fn().mockReturnValue(senderId),
+                getId: jest.fn(),
+                getStateKey: jest.fn(),
+                getContent: jest.fn().mockReturnValue({ msgtype: msgtype }),
+                getTs: jest.fn(),
+            } as unknown as MatrixEvent;
+        }
+    });
 });
 
 /** Build a MatrixHttpApi instance */

spec/unit/sync-accumulator.spec.ts

@@ -26,6 +26,7 @@ import {
     type ILeftRoom,
     type IRoomEvent,
     type IStateEvent,
+    type IStickyEvent,
     type IStrippedState,
     type ISyncResponse,
     SyncAccumulator,
@@ -1067,6 +1068,67 @@ describe("SyncAccumulator", function () {
             );
         });
     });
+
+    describe("MSC4354 sticky events", () => {
+        function stickyEvent(ts = 0): IStickyEvent {
+            const msgData = msg("test", "test text");
+            return {
+                ...msgData,
+                msc4354_sticky: {
+                    duration_ms: 1000,
+                },
+                origin_server_ts: ts,
+            };
+        }
+
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+
+        it("should accumulate sticky events", () => {
+            jest.setSystemTime(0);
+            const ev = stickyEvent();
+            sa.accumulate(
+                syncSkeleton({
+                    msc4354_sticky: {
+                        events: [ev],
+                    },
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([ev]);
+        });
+        it("should clear stale sticky events", () => {
+            jest.setSystemTime(1000);
+            const ev = stickyEvent(1000);
+            sa.accumulate(
+                syncSkeleton({
+                    msc4354_sticky: {
+                        events: [ev],
+                    },
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([ev]);
+            jest.setSystemTime(2000); // Expire the event
+            sa.accumulate(syncSkeleton({}));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toBeUndefined();
+        });
+
+        it("clears stale sticky events that pretend to be from the distant future", () => {
+            jest.setSystemTime(0);
+            const eventFarInTheFuture = stickyEvent(999999999999);
+            sa.accumulate(syncSkeleton({ msc4354_sticky: { events: [eventFarInTheFuture] } }));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([
+                eventFarInTheFuture,
+            ]);
+            jest.setSystemTime(1000); // Expire the event
+            sa.accumulate(syncSkeleton({}));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toBeUndefined();
+        });
+    });
 });
 
 function syncSkeleton(

src/@types/event.ts

@@ -58,7 +58,7 @@ import {
     type ICallNotifyContent,
 } from "../matrixrtc/types.ts";
 import { type M_POLL_END, type M_POLL_START, type PollEndEventContent, type PollStartEventContent } from "./polls.ts";
-import { type SessionMembershipData } from "../matrixrtc/CallMembership.ts";
+import { type RtcMembershipData, type SessionMembershipData } from "../matrixrtc/CallMembership.ts";
 import { type LocalNotificationSettings } from "./local_notifications.ts";
 import { type IPushRules } from "./PushRules.ts";
 import { type SecretInfo, type SecretStorageKeyDescription } from "../secret-storage.ts";
@@ -151,6 +151,7 @@ export enum EventType {
     GroupCallMemberPrefix = "org.matrix.msc3401.call.member",
 
     // MatrixRTC events
+    RTCMembership = "org.matrix.msc4143.rtc.member",
     CallNotify = "org.matrix.msc4075.call.notify",
     RTCNotification = "org.matrix.msc4075.rtc.notification",
     RTCDecline = "org.matrix.msc4310.rtc.decline",
@@ -337,6 +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.
 }
 
 /**
@@ -369,7 +371,7 @@ export interface StateEvents {
     // MSC3401
     [EventType.GroupCallPrefix]: IGroupCallRoomState;
     [EventType.GroupCallMemberPrefix]: IGroupCallRoomMemberState | SessionMembershipData | EmptyObject;
-
+    [EventType.RTCMembership]: RtcMembershipData | EmptyObject;
     // MSC3089
     [UNSTABLE_MSC3089_BRANCH.name]: MSC3089EventContent;
 

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";
 
@@ -34,6 +35,7 @@ export interface IJoinRoomOpts {
 
     /**
      * The server names to try and join through in addition to those that are automatically chosen.
+     * Only the first 3 are actually used in the request, to avoid HTTP 414 Request-URI Too Long responses.
      */
     viaServers?: string[];
 
@@ -71,6 +73,7 @@ export interface KnockRoomOpts {
 
     /**
      * The server names to try and knock through in addition to those that are automatically chosen.
+     * Only the first 3 are actually used in the request, to avoid HTTP 414 Request-URI Too Long responses.
      */
     viaServers?: string | string[];
 }
@@ -94,19 +97,20 @@ export interface ISendEventResponse {
     event_id: string;
 }
 
-export type TimeoutDelay = {
-    delay: number;
-};
-
-export type ParentDelayId = {
-    parent_delay_id: string;
-};
-
-export type SendTimeoutDelayedEventRequestOpts = TimeoutDelay & Partial<ParentDelayId>;
-export type SendActionDelayedEventRequestOpts = ParentDelayId;
-
-export type SendDelayedEventRequestOpts = SendTimeoutDelayedEventRequestOpts | SendActionDelayedEventRequestOpts;
+export type SendDelayedEventRequestOpts = { parent_delay_id: string } | { delay: number; parent_delay_id?: string };
 
+export function isSendDelayedEventRequestOpts(opts: object): opts is SendDelayedEventRequestOpts {
+    if ("parent_delay_id" in opts && typeof opts.parent_delay_id !== "string") {
+        // Invalid type, reject
+        return false;
+    }
+    if ("delay" in opts && typeof opts.delay !== "number") {
+        // Invalid type, reject.
+        return true;
+    }
+    // At least one of these fields must be specified.
+    return "delay" in opts || "parent_delay_id" in opts;
+}
 export type SendDelayedEventResponse = {
     delay_id: string;
 };
@@ -133,12 +137,22 @@ type DelayedPartialStateEvent = DelayedPartialTimelineEvent & {
 
 type DelayedPartialEvent = DelayedPartialTimelineEvent | DelayedPartialStateEvent;
 
+export type DelayedEventInfoItem = DelayedPartialEvent &
+    SendDelayedEventResponse &
+    SendDelayedEventRequestOpts & {
+        running_since: number;
+    };
+
 export type DelayedEventInfo = {
-    delayed_events: (DelayedPartialEvent &
-        SendDelayedEventResponse &
-        SendDelayedEventRequestOpts & {
-            running_since: number;
-        })[];
+    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/@types/state_events.ts

@@ -105,9 +105,10 @@ export interface RoomPinnedEventsEventContent {
 }
 
 export interface RoomEncryptionEventContent {
-    algorithm: "m.megolm.v1.aes-sha2";
-    rotation_period_ms?: number;
-    rotation_period_msgs?: number;
+    "algorithm": "m.megolm.v1.aes-sha2";
+    "io.element.msc3414.encrypt_state_events"?: boolean;
+    "rotation_period_ms"?: number;
+    "rotation_period_msgs"?: number;
 }
 
 export interface RoomHistoryVisibilityEventContent {

src/client.ts

@@ -105,6 +105,7 @@ import {
 import { RoomMemberEvent, type RoomMemberEventHandlerMap } from "./models/room-member.ts";
 import { type IPowerLevelsContent, type RoomStateEvent, type RoomStateEventHandlerMap } from "./models/room-state.ts";
 import {
+    isSendDelayedEventRequestOpts,
     type DelayedEventInfo,
     type IAddThreePidOnlyBody,
     type IBindThreePidBody,
@@ -246,7 +247,7 @@ import {
     validateAuthMetadataAndKeys,
 } from "./oidc/index.ts";
 import { type EmptyObject } from "./@types/common.ts";
-import { UnsupportedDelayedEventsEndpointError } from "./errors.ts";
+import { UnsupportedDelayedEventsEndpointError, UnsupportedStickyEventsEndpointError } from "./errors.ts";
 
 export type Store = IStore;
 
@@ -425,6 +426,11 @@ export interface ICreateClientOpts {
      */
     cryptoCallbacks?: CryptoCallbacks;
 
+    /**
+     * Enable encrypted state events.
+     */
+    enableEncryptedStateEvents?: boolean;
+
     /**
      * Method to generate room names for empty rooms and rooms names based on membership.
      * Defaults to a built-in English handler with basic pluralisation.
@@ -438,6 +444,12 @@ export interface ICreateClientOpts {
      */
     isVoipWithNoMediaAllowed?: boolean;
 
+    /**
+     * Disable VoIP support (prevents fetching TURN servers, etc.)
+     * Default: false (VoIP enabled)
+     */
+    disableVoip?: boolean;
+
     /**
      * If true, group calls will not establish media connectivity and only create the signaling events,
      * so that livekit media can be used in the application layer (js-sdk contains no livekit code).
@@ -540,6 +552,7 @@ export const UNSTABLE_MSC2666_MUTUAL_ROOMS = "uk.half-shot.msc2666.mutual_rooms"
 export const UNSTABLE_MSC2666_QUERY_MUTUAL_ROOMS = "uk.half-shot.msc2666.query_mutual_rooms";
 
 export const UNSTABLE_MSC4140_DELAYED_EVENTS = "org.matrix.msc4140";
+export const UNSTABLE_MSC4354_STICKY_EVENTS = "org.matrix.msc4354";
 
 export const UNSTABLE_MSC4133_EXTENDED_PROFILES = "uk.tcpip.msc4133";
 export const STABLE_MSC4133_EXTENDED_PROFILES = "uk.tcpip.msc4133.stable";
@@ -1205,6 +1218,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     public http: MatrixHttpApi<IHttpOpts & { onlyData: true }>; // XXX: Intended private, used in code.
 
     private cryptoBackend?: CryptoBackend; // one of crypto or rustCrypto
+    private readonly enableEncryptedStateEvents: boolean;
     public cryptoCallbacks: CryptoCallbacks; // XXX: Intended private, used in code.
     public callEventHandler?: CallEventHandler; // XXX: Intended private, used in code.
     public groupCallEventHandler?: GroupCallEventHandler;
@@ -1214,6 +1228,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     public idBaseUrl?: string;
     public baseUrl: string;
     public readonly isVoipWithNoMediaAllowed;
+    public disableVoip: boolean;
 
     public useLivekitForGroupCalls: boolean;
 
@@ -1340,7 +1355,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             });
         }
 
-        if (supportsMatrixCall()) {
+        this.disableVoip = opts.disableVoip ?? false;
+
+        if (!this.disableVoip && supportsMatrixCall()) {
             this.callEventHandler = new CallEventHandler(this);
             this.groupCallEventHandler = new GroupCallEventHandler(this);
             this.canSupportVoip = true;
@@ -1363,6 +1380,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         this.legacyCryptoStore = opts.cryptoStore;
         this.verificationMethods = opts.verificationMethods;
         this.cryptoCallbacks = opts.cryptoCallbacks || {};
+        this.enableEncryptedStateEvents = opts.enableEncryptedStateEvents ?? false;
 
         this.forceTURN = opts.forceTURN || false;
         this.iceCandidatePoolSize = opts.iceCandidatePoolSize === undefined ? 0 : opts.iceCandidatePoolSize;
@@ -1426,7 +1444,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         // periodically poll for turn servers if we support voip
-        if (this.canSupportVoip) {
+        if (this.supportsVoip()) {
             this.checkTurnServersIntervalID = setInterval(() => {
                 this.checkTurnServers();
             }, TURN_CHECK_INTERVAL);
@@ -1663,7 +1681,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns True if VoIP is supported.
      */
     public supportsVoip(): boolean {
-        return this.canSupportVoip;
+        return !this.disableVoip && this.canSupportVoip;
     }
 
     /**
@@ -1979,6 +1997,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             legacyMigrationProgressListener: (progress: number, total: number): void => {
                 this.emit(CryptoEvent.LegacyCryptoStoreMigrationProgress, progress, total);
             },
+
+            enableEncryptedStateEvents: this.enableEncryptedStateEvents,
         });
 
         rustCrypto.setSupportedVerificationMethods(this.verificationMethods);
@@ -2373,8 +2393,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         const queryParams: QueryDict = {};
         if (opts.viaServers) {
             // server_name has been deprecated in favour of via with Matrix >1.11 (MSC4156)
-            queryParams.server_name = opts.viaServers;
-            queryParams.via = opts.viaServers;
+            // We only use the first 3 servers, to avoid URI length issues.
+            queryParams.via = queryParams.server_name = opts.viaServers.slice(0, 3);
         }
 
         const data: IJoinRequestBody = {};
@@ -2418,9 +2438,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         const queryParams: QueryDict = {};
         if (opts.viaServers) {
+            // We only use the first 3 servers, to avoid URI length issues.
+            const viaServers = Array.isArray(opts.viaServers) ? opts.viaServers.slice(0, 3) : [opts.viaServers];
             // server_name has been deprecated in favour of via with Matrix >1.11 (MSC4156)
-            queryParams.server_name = opts.viaServers;
-            queryParams.via = opts.viaServers;
+            queryParams.server_name = viaServers;
+            queryParams.via = viaServers;
         }
 
         const body: Record<string, string> = {};
@@ -2663,7 +2685,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         this.addThreadRelationIfNeeded(content, threadId, roomId);
-        return this.sendCompleteEvent(roomId, threadId, { type: eventType, content }, txnId);
+        return this.sendCompleteEvent({ roomId, threadId, eventObject: { type: eventType, content }, txnId });
     }
 
     /**
@@ -2700,12 +2722,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Promise which resolves: to an empty object `{}`
      * @returns Rejects: with an error response.
      */
-    private sendCompleteEvent(
-        roomId: string,
-        threadId: string | null,
-        eventObject: Partial<IEvent>,
-        txnId?: string,
-    ): Promise<ISendEventResponse>;
+    private sendCompleteEvent(params: {
+        roomId: string;
+        threadId: string | null;
+        eventObject: Partial<IEvent>;
+        queryDict?: QueryDict;
+        txnId?: string;
+    }): Promise<ISendEventResponse>;
     /**
      * Sends a delayed event (MSC4140).
      * @param eventObject - An object with the partial structure of an event, to which event_id, user_id, room_id and origin_server_ts will be added.
@@ -2714,29 +2737,29 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Promise which resolves: to an empty object `{}`
      * @returns Rejects: with an error response.
      */
-    private sendCompleteEvent(
-        roomId: string,
-        threadId: string | null,
-        eventObject: Partial<IEvent>,
-        delayOpts: SendDelayedEventRequestOpts,
-        txnId?: string,
-    ): Promise<SendDelayedEventResponse>;
-    private sendCompleteEvent(
-        roomId: string,
-        threadId: string | null,
-        eventObject: Partial<IEvent>,
-        delayOptsOrTxnId?: SendDelayedEventRequestOpts | string,
-        txnIdOrVoid?: string,
-    ): Promise<ISendEventResponse | SendDelayedEventResponse> {
-        let delayOpts: SendDelayedEventRequestOpts | undefined;
-        let txnId: string | undefined;
-        if (typeof delayOptsOrTxnId === "string") {
-            txnId = delayOptsOrTxnId;
-        } else {
-            delayOpts = delayOptsOrTxnId;
-            txnId = txnIdOrVoid;
-        }
-
+    private sendCompleteEvent(params: {
+        roomId: string;
+        threadId: string | null;
+        eventObject: Partial<IEvent>;
+        delayOpts: SendDelayedEventRequestOpts;
+        queryDict?: QueryDict;
+        txnId?: string;
+    }): Promise<SendDelayedEventResponse>;
+    private sendCompleteEvent({
+        roomId,
+        threadId,
+        eventObject,
+        delayOpts,
+        queryDict,
+        txnId,
+    }: {
+        roomId: string;
+        threadId: string | null;
+        eventObject: Partial<IEvent>;
+        delayOpts?: SendDelayedEventRequestOpts;
+        queryDict?: QueryDict;
+        txnId?: string;
+    }): Promise<SendDelayedEventResponse | ISendEventResponse> {
         if (!txnId) {
             txnId = this.makeTxnId();
         }
@@ -2779,7 +2802,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         const type = localEvent.getType();
         this.logger.debug(
-            `sendEvent of type ${type} in ${roomId} with txnId ${txnId}${delayOpts ? " (delayed event)" : ""}`,
+            `sendEvent of type ${type} in ${roomId} with txnId ${txnId}${delayOpts ? " (delayed event)" : ""}${queryDict ? " query params: " + JSON.stringify(queryDict) : ""}`,
         );
 
         localEvent.setTxnId(txnId);
@@ -2797,9 +2820,9 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 return Promise.reject(new Error("Event blocked by other events not yet sent"));
             }
 
-            return this.encryptAndSendEvent(room, localEvent);
+            return this.encryptAndSendEvent(room, localEvent, queryDict);
         } else {
-            return this.encryptAndSendEvent(room, localEvent, delayOpts);
+            return this.encryptAndSendEvent(room, localEvent, delayOpts, queryDict);
         }
     }
 
@@ -2807,7 +2830,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * encrypts the event if necessary; adds the event to the queue, or sends it; marks the event as sent/unsent
      * @returns returns a promise which resolves with the result of the send request
      */
-    protected async encryptAndSendEvent(room: Room | null, event: MatrixEvent): Promise<ISendEventResponse>;
+    protected async encryptAndSendEvent(
+        room: Room | null,
+        event: MatrixEvent,
+        queryDict?: QueryDict,
+    ): Promise<ISendEventResponse>;
     /**
      * Simply sends a delayed event without encrypting it.
      * TODO: Allow encrypted delayed events, and encrypt them properly
@@ -2818,16 +2845,20 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         room: Room | null,
         event: MatrixEvent,
         delayOpts: SendDelayedEventRequestOpts,
-    ): Promise<SendDelayedEventResponse>;
+        queryDict?: QueryDict,
+    ): Promise<ISendEventResponse>;
     protected async encryptAndSendEvent(
         room: Room | null,
         event: MatrixEvent,
-        delayOpts?: SendDelayedEventRequestOpts,
+        delayOptsOrQuery?: SendDelayedEventRequestOpts | QueryDict,
+        queryDict?: QueryDict,
     ): Promise<ISendEventResponse | SendDelayedEventResponse> {
-        if (delayOpts) {
-            return this.sendEventHttpRequest(event, delayOpts);
+        let queryOpts = queryDict;
+        if (delayOptsOrQuery && isSendDelayedEventRequestOpts(delayOptsOrQuery)) {
+            return this.sendEventHttpRequest(event, delayOptsOrQuery, queryOpts);
+        } else if (!queryOpts) {
+            queryOpts = delayOptsOrQuery;
         }
-
         try {
             let cancelled: boolean;
             this.eventsBeingEncrypted.add(event.getId()!);
@@ -2863,7 +2894,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             }
 
             if (!promise) {
-                promise = this.sendEventHttpRequest(event);
+                promise = this.sendEventHttpRequest(event, queryOpts);
                 if (room) {
                     promise = promise.then((res) => {
                         room.updatePendingEvent(event, EventStatus.SENT, res["event_id"]);
@@ -2978,14 +3009,16 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
     }
 
-    private sendEventHttpRequest(event: MatrixEvent): Promise<ISendEventResponse>;
+    private sendEventHttpRequest(event: MatrixEvent, queryDict?: QueryDict): Promise<ISendEventResponse>;
     private sendEventHttpRequest(
         event: MatrixEvent,
         delayOpts: SendDelayedEventRequestOpts,
+        queryDict?: QueryDict,
     ): Promise<SendDelayedEventResponse>;
     private sendEventHttpRequest(
         event: MatrixEvent,
-        delayOpts?: SendDelayedEventRequestOpts,
+        queryOrDelayOpts?: SendDelayedEventRequestOpts | QueryDict,
+        queryDict?: QueryDict,
     ): Promise<ISendEventResponse | SendDelayedEventResponse> {
         let txnId = event.getTxnId();
         if (!txnId) {
@@ -3018,19 +3051,22 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             path = utils.encodeUri("/rooms/$roomId/send/$eventType/$txnId", pathParams);
         }
 
+        const delayOpts =
+            queryOrDelayOpts && isSendDelayedEventRequestOpts(queryOrDelayOpts) ? queryOrDelayOpts : undefined;
+        const queryOpts = !delayOpts ? queryOrDelayOpts : queryDict;
         const content = event.getWireContent();
-        if (!delayOpts) {
-            return this.http.authedRequest<ISendEventResponse>(Method.Put, path, undefined, content).then((res) => {
-                this.logger.debug(`Event sent to ${event.getRoomId()} with event id ${res.event_id}`);
-                return res;
-            });
-        } else {
+        if (delayOpts) {
             return this.http.authedRequest<SendDelayedEventResponse>(
                 Method.Put,
                 path,
-                getUnstableDelayQueryOpts(delayOpts),
+                { ...getUnstableDelayQueryOpts(delayOpts), ...queryOpts },
                 content,
             );
+        } else {
+            return this.http.authedRequest<ISendEventResponse>(Method.Put, path, queryOpts, content).then((res) => {
+                this.logger.debug(`Event sent to ${event.getRoomId()} with event id ${res.event_id}`);
+                return res;
+            });
         }
     }
 
@@ -3087,16 +3123,16 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             content[withRelTypesPropName] = opts.with_rel_types;
         }
 
-        return this.sendCompleteEvent(
+        return this.sendCompleteEvent({
             roomId,
             threadId,
-            {
+            eventObject: {
                 type: EventType.RoomRedaction,
                 content,
                 redacts: eventId,
             },
-            txnId as string,
-        );
+            txnId: txnId as string,
+        });
     }
 
     /**
@@ -3384,7 +3420,54 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         this.addThreadRelationIfNeeded(content, threadId, roomId);
-        return this.sendCompleteEvent(roomId, threadId, { type: eventType, content }, delayOpts, txnId);
+        return this.sendCompleteEvent({
+            roomId,
+            threadId,
+            eventObject: { type: eventType, content },
+            delayOpts,
+            txnId,
+        });
+    }
+
+    /**
+     * Send a delayed sticky timeline event.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) and
+     *   [MSC4354](https://github.com/matrix-org/matrix-spec-proposals/pull/4354) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_sendStickyDelayedEvent<K extends keyof TimelineEvents>(
+        roomId: string,
+        stickDuration: number,
+        delayOpts: SendDelayedEventRequestOpts,
+        threadId: string | null,
+        eventType: K,
+        content: TimelineEvents[K] & { msc4354_sticky_key: string },
+        txnId?: string,
+    ): Promise<SendDelayedEventResponse> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw new UnsupportedDelayedEventsEndpointError(
+                "Server does not support the delayed events API",
+                "getDelayedEvents",
+            );
+        }
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4354_STICKY_EVENTS))) {
+            throw new UnsupportedStickyEventsEndpointError(
+                "Server does not support the sticky events",
+                "sendStickyEvent",
+            );
+        }
+
+        this.addThreadRelationIfNeeded(content, threadId, roomId);
+        return this.sendCompleteEvent({
+            roomId,
+            threadId,
+            eventObject: { type: eventType, content },
+            queryDict: { "org.matrix.msc4354.sticky_duration_ms": stickDuration },
+            delayOpts,
+            txnId,
+        });
     }
 
     /**
@@ -3422,13 +3505,49 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     /**
-     * Get all pending delayed events for the calling user.
+     * Send a sticky timeline event.
+     *
+     * Note: This endpoint is unstable, and can throw an `Error`.
+     *   Check progress on [MSC4354](https://github.com/matrix-org/matrix-spec-proposals/pull/4354) for more details.
+     */
+    // eslint-disable-next-line
+    public async _unstable_sendStickyEvent<K extends keyof TimelineEvents>(
+        roomId: string,
+        stickDuration: number,
+        threadId: string | null,
+        eventType: K,
+        content: TimelineEvents[K] & { msc4354_sticky_key: string },
+        txnId?: string,
+    ): Promise<ISendEventResponse> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4354_STICKY_EVENTS))) {
+            throw new UnsupportedStickyEventsEndpointError(
+                "Server does not support the sticky events",
+                "sendStickyEvent",
+            );
+        }
+
+        this.addThreadRelationIfNeeded(content, threadId, roomId);
+        return this.sendCompleteEvent({
+            roomId,
+            threadId,
+            eventObject: { type: eventType, content },
+            queryDict: { "org.matrix.msc4354.sticky_duration_ms": stickDuration },
+            txnId,
+        });
+    }
+
+    /**
+     * 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",
@@ -3436,7 +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}`,
         });
@@ -5613,7 +5736,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
     // XXX: Intended private, used in code.
     public async checkTurnServers(): Promise<boolean | undefined> {
-        if (!this.canSupportVoip) {
+        if (!this.supportsVoip()) {
             return;
         }
 
@@ -6034,6 +6157,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns A decryption promise
      */
     public decryptEventIfNeeded(event: MatrixEvent, options?: IDecryptOptions): Promise<void> {
+        if (event.isState() && !this.enableEncryptedStateEvents) {
+            return Promise.resolve();
+        }
+
         if (event.shouldAttemptDecryption() && this.getCrypto()) {
             event.attemptDecryption(this.cryptoBackend!, options);
         }
@@ -6618,23 +6745,83 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Promise which resolves: TODO
      * @returns Rejects: with an error response.
      */
-    public sendStateEvent<K extends keyof StateEvents>(
+    public async sendStateEvent<K extends keyof StateEvents>(
         roomId: string,
         eventType: K,
         content: StateEvents[K],
         stateKey = "",
         opts: IRequestOpts = {},
     ): Promise<ISendEventResponse> {
+        const room = this.getRoom(roomId);
+        const event = new MatrixEvent({
+            room_id: roomId,
+            type: eventType,
+            state_key: stateKey,
+            // Cast safety: StateEvents[K] is a stronger bound than IContent, which has [key: string]: any
+            content: content as IContent,
+        });
+
+        await this.encryptStateEventIfNeeded(event, room ?? undefined);
+
         const pathParams = {
             $roomId: roomId,
-            $eventType: eventType,
-            $stateKey: stateKey,
+            $eventType: event.getWireType(),
+            $stateKey: event.getWireStateKey(),
         };
         let path = utils.encodeUri("/rooms/$roomId/state/$eventType", pathParams);
         if (stateKey !== undefined) {
             path = utils.encodeUri(path + "/$stateKey", pathParams);
         }
-        return this.http.authedRequest(Method.Put, path, undefined, content as Body, opts);
+        return this.http.authedRequest(Method.Put, path, undefined, event.getWireContent(), opts);
+    }
+
+    private async encryptStateEventIfNeeded(event: MatrixEvent, room?: Room): Promise<void> {
+        if (!this.enableEncryptedStateEvents) {
+            return;
+        }
+
+        // If the room is unknown, we cannot encrypt for it
+        if (!room) return;
+
+        if (!this.cryptoBackend && this.usingExternalCrypto) {
+            // The client has opted to allow sending messages to encrypted
+            // rooms even if the room is encrypted, and we haven't set up
+            // crypto. This is useful for users of matrix-org/pantalaimon
+            return;
+        }
+
+        if (!this.cryptoBackend) {
+            throw new Error("This room is configured to use encryption, but your client does not support encryption.");
+        }
+
+        // Check regular encryption conditions.
+        if (!(await this.shouldEncryptEventForRoom(event, room))) {
+            return;
+        }
+
+        // If the crypto impl thinks we shouldn't encrypt, then we shouldn't.
+        // Safety: we checked the crypto impl exists above.
+        if (!(await this.cryptoBackend!.isStateEncryptionEnabledInRoom(room.roomId))) {
+            return;
+        }
+
+        // Check if the event is excluded under MSC3414
+        if (
+            [
+                "m.room.create",
+                "m.room.member",
+                "m.room.join_rules",
+                "m.room.power_levels",
+                "m.room.third_party_invite",
+                "m.room.history_visibility",
+                "m.room.guest_access",
+                "m.room.encryption",
+            ].includes(event.getType())
+        ) {
+            return;
+        }
+
+        await this.cryptoBackend.encryptEvent(event, room);
     }
 
     /**
@@ -6898,6 +7085,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      */
     public async doesServerSupportExtendedProfiles(): Promise<boolean> {
         return (
+            (await this.isVersionSupported("v1.16")) ||
             (await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4133_EXTENDED_PROFILES)) ||
             (await this.doesServerSupportUnstableFeature(STABLE_MSC4133_EXTENDED_PROFILES))
         );
@@ -6909,7 +7097,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns The prefix for use with `authedRequest`
      */
     private async getExtendedProfileRequestPrefix(): Promise<string> {
-        if (await this.doesServerSupportUnstableFeature("uk.tcpip.msc4133.stable")) {
+        if (
+            (await this.isVersionSupported("v1.16")) ||
+            (await this.doesServerSupportUnstableFeature("uk.tcpip.msc4133.stable"))
+        ) {
             return ClientPrefix.V3;
         }
         return "/_matrix/client/unstable/uk.tcpip.msc4133";

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,
@@ -118,6 +118,11 @@ export interface CryptoApi {
      */
     isEncryptionEnabledInRoom(roomId: string): Promise<boolean>;
 
+    /**
+     * Check if we believe the given room supports encrypted state events.
+     */
+    isStateEncryptionEnabledInRoom(roomId: string): Promise<boolean>;
+
     /**
      * Perform any background tasks that can be done before a message is ready to
      * send, in order to speed up sending of the message.
@@ -364,6 +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).
      *
@@ -1143,6 +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/errors.ts

@@ -54,7 +54,7 @@ export class ClientStoppedError extends Error {
 }
 
 /**
- * This error is thrown when the Homeserver does not support the delayed events enpdpoints.
+ * This error is thrown when the Homeserver does not support the delayed events endpoints.
  */
 export class UnsupportedDelayedEventsEndpointError extends Error {
     public constructor(
@@ -65,3 +65,16 @@ export class UnsupportedDelayedEventsEndpointError extends Error {
         this.name = "UnsupportedDelayedEventsEndpointError";
     }
 }
+
+/**
+ * This error is thrown when the Homeserver does not support the sticky events endpoints.
+ */
+export class UnsupportedStickyEventsEndpointError extends Error {
+    public constructor(
+        message: string,
+        public clientEndpoint: "sendStickyEvent" | "sendStickyStateEvent",
+    ) {
+        super(message);
+        this.name = "UnsupportedStickyEventsEndpointError";
+    }
+}

src/matrixrtc/CallMembership.ts

@@ -14,11 +14,14 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type MatrixEvent } from "../matrix.ts";
+import { MXID_PATTERN } from "../models/room-member.ts";
 import { deepCompare } from "../utils.ts";
-import { type Focus } from "./focus.ts";
-import { isLivekitFocusActive } from "./LivekitFocus.ts";
-import { type SessionDescription } from "./MatrixRTCSession.ts";
+import { type LivekitFocusSelection } from "./LivekitTransport.ts";
+import { slotDescriptionToId, slotIdToDescription, type SlotDescription } from "./MatrixRTCSession.ts";
+import type { RTCCallIntent, Transport } from "./types.ts";
+import { type IContent, type MatrixEvent } from "../models/event.ts";
+import { type RelationType } from "../@types/event.ts";
+import { logger } from "../logger.ts";
 
 /**
  * The default duration in milliseconds that a membership is considered valid for.
@@ -28,16 +31,116 @@ import { type SessionDescription } from "./MatrixRTCSession.ts";
 export const DEFAULT_EXPIRE_DURATION = 1000 * 60 * 60 * 4;
 
 type CallScope = "m.room" | "m.user";
+type Member = { user_id: string; device_id: string; id: string };
+
+export interface RtcMembershipData {
+    "slot_id": string;
+    "member": Member;
+    "m.relates_to"?: {
+        event_id: string;
+        rel_type: RelationType.Reference;
+    };
+    "application": {
+        type: string;
+        // other application specific keys
+        [key: string]: unknown;
+    };
+    "rtc_transports": Transport[];
+    "versions": string[];
+    "msc4354_sticky_key"?: string;
+    "sticky_key"?: string;
+}
+
+const checkRtcMembershipData = (
+    data: IContent,
+    errors: string[],
+    referenceUserId: string,
+): data is RtcMembershipData => {
+    const prefix = " - ";
+
+    // required fields
+    if (typeof data.slot_id !== "string") {
+        errors.push(prefix + "slot_id must be string");
+    } else {
+        if (data.slot_id.split("#").length !== 2) errors.push(prefix + 'slot_id must include exactly one "#"');
+    }
+    if (typeof data.member !== "object" || data.member === null) {
+        errors.push(prefix + "member must be an object");
+    } else {
+        if (typeof data.member.user_id !== "string") errors.push(prefix + "member.user_id must be string");
+        else if (!MXID_PATTERN.test(data.member.user_id)) errors.push(prefix + "member.user_id must be a valid mxid");
+        // This is not what the spec enforces but there currently are no rules what power levels are required to
+        // send a m.rtc.member event for a other user. So we add this check for simplicity and to avoid possible attacks until there
+        // is a proper definition when this is allowed.
+        else if (data.member.user_id !== referenceUserId) errors.push(prefix + "member.user_id must match the sender");
+        if (typeof data.member.device_id !== "string") errors.push(prefix + "member.device_id must be string");
+        if (typeof data.member.id !== "string") errors.push(prefix + "member.id must be string");
+    }
+    if (typeof data.application !== "object" || data.application === null) {
+        errors.push(prefix + "application must be an object");
+    } else {
+        if (typeof data.application.type !== "string") {
+            errors.push(prefix + "application.type must be a string");
+        } else {
+            if (data.application.type.includes("#")) errors.push(prefix + 'application.type must not include "#"');
+        }
+    }
+    if (data.rtc_transports === undefined || !Array.isArray(data.rtc_transports)) {
+        errors.push(prefix + "rtc_transports must be an array");
+    } else {
+        // validate that each transport has at least a string 'type'
+        for (const t of data.rtc_transports) {
+            if (typeof t !== "object" || t === null || typeof (t as any).type !== "string") {
+                errors.push(prefix + "rtc_transports entries must be objects with a string type");
+                break;
+            }
+        }
+    }
+    if (data.versions === undefined || !Array.isArray(data.versions)) {
+        errors.push(prefix + "versions must be an array");
+    } else if (!data.versions.every((v) => typeof v === "string")) {
+        errors.push(prefix + "versions must be an array of strings");
+    }
+
+    // optional fields
+    if ((data.sticky_key ?? data.msc4354_sticky_key) === undefined) {
+        errors.push(prefix + "sticky_key or msc4354_sticky_key must be a defined");
+    }
+    if (data.sticky_key !== undefined && typeof data.sticky_key !== "string") {
+        errors.push(prefix + "sticky_key must be a string");
+    }
+    if (data.msc4354_sticky_key !== undefined && typeof data.msc4354_sticky_key !== "string") {
+        errors.push(prefix + "msc4354_sticky_key must be a string");
+    }
+    if (
+        data.sticky_key !== undefined &&
+        data.msc4354_sticky_key !== undefined &&
+        data.sticky_key !== data.msc4354_sticky_key
+    ) {
+        errors.push(prefix + "sticky_key and msc4354_sticky_key must be equal if both are defined");
+    }
+    if (data["m.relates_to"] !== undefined) {
+        const rel = data["m.relates_to"] as RtcMembershipData["m.relates_to"];
+        if (typeof rel !== "object" || rel === null) {
+            errors.push(prefix + "m.relates_to must be an object if provided");
+        } else {
+            if (typeof rel.event_id !== "string") errors.push(prefix + "m.relates_to.event_id must be a string");
+            if (rel.rel_type !== "m.reference") errors.push(prefix + "m.relates_to.rel_type must be m.reference");
+        }
+    }
+
+    return errors.length === 0;
+};
 
 /**
  * MSC4143 (MatrixRTC) session membership data.
- * Represents an entry in the memberships section of an m.call.member event as it is on the wire.
+ * Represents the `session` in the memberships section of an m.call.member event as it is on the wire.
  **/
 export type SessionMembershipData = {
     /**
      * The RTC application defines the type of the RTC session.
      */
-    application: string;
+    "application": string;
 
     /**
      * The id of this session.
@@ -45,23 +148,23 @@ export type SessionMembershipData = {
      * multiple session in one room. A room wide session that is not associated with a user,
      * and therefore immune to creation race conflicts, uses the `call_id: ""`.
      */
-    call_id: string;
+    "call_id": string;
 
     /**
      * The Matrix device ID of this session. A single user can have multiple sessions on different devices.
      */
-    device_id: string;
+    "device_id": string;
 
     /**
      * The focus selection system this user/membership is using.
      */
-    focus_active: Focus;
+    "focus_active": LivekitFocusSelection;
 
     /**
-     * A list of possible foci this uses knows about. One of them might be used based on the focus_active
+     * A list of possible foci this user knows about. One of them might be used based on the focus_active
      * selection system.
      */
-    foci_preferred: Focus[];
+    "foci_preferred": Transport[];
 
     /**
      * Optional field that contains the creation of the session. If it is undefined the creation
@@ -70,138 +173,341 @@ export type SessionMembershipData = {
      *  - If it is undefined it can be interpreted as a "Join".
      *  - If it is defined it can be interpreted as an "Update"
      */
-    created_ts?: number;
+    "created_ts"?: number;
 
     // Application specific data
 
     /**
      * If the `application` = `"m.call"` this defines if it is a room or user owned call.
-     * There can always be one room scroped call but multiple user owned calls (breakout sessions)
+     * There can always be one room scoped call but multiple user owned calls (breakout sessions)
      */
-    scope?: CallScope;
+    "scope"?: CallScope;
 
     /**
      * Optionally we allow to define a delta to the `created_ts` that defines when the event is expired/invalid.
      * This should be set to multiple hours. The only reason it exist is to deal with failed delayed events.
      * (for example caused by a homeserver crashes)
      **/
-    expires?: number;
+    "expires"?: number;
+
+    /**
+     * The intent of the call from the perspective of this user. This may be an audio call, video call or
+     * 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: any, errors: string[]): data is SessionMembershipData => {
-    const prefix = "Malformed session membership event: ";
+const checkSessionsMembershipData = (data: IContent, errors: string[]): data is SessionMembershipData => {
+    const prefix = " - ";
     if (typeof data.device_id !== "string") errors.push(prefix + "device_id must be string");
     if (typeof data.call_id !== "string") errors.push(prefix + "call_id must be string");
     if (typeof data.application !== "string") errors.push(prefix + "application must be a string");
     if (typeof data.focus_active?.type !== "string") errors.push(prefix + "focus_active.type must be a string");
-    if (!Array.isArray(data.foci_preferred)) errors.push(prefix + "foci_preferred must be an array");
+    if (data.focus_active === undefined) {
+        errors.push(prefix + "focus_active has an invalid type");
+    }
+    if (
+        data.foci_preferred !== undefined &&
+        !(
+            Array.isArray(data.foci_preferred) &&
+            data.foci_preferred.every(
+                (f: Transport) => typeof f === "object" && f !== null && typeof f.type === "string",
+            )
+        )
+    ) {
+        errors.push(prefix + "foci_preferred must be an array of transport objects");
+    }
     // optional parameters
-    if (data.created_ts && typeof data.created_ts !== "number") errors.push(prefix + "created_ts must be number");
+    if (data.created_ts !== undefined && typeof data.created_ts !== "number") {
+        errors.push(prefix + "created_ts must be number");
+    }
 
     // application specific data (we first need to check if they exist)
-    if (data.scope && typeof data.scope !== "string") errors.push(prefix + "scope must be string");
+    if (data.scope !== undefined && typeof data.scope !== "string") errors.push(prefix + "scope must be string");
+
+    if (data["m.call.intent"] !== undefined && typeof data["m.call.intent"] !== "string") {
+        errors.push(prefix + "m.call.intent must be a string");
+    }
+
     return errors.length === 0;
 };
 
+type MembershipData = { kind: "rtc"; data: RtcMembershipData } | { kind: "session"; data: SessionMembershipData };
+// TODO: Rename to RtcMembership once we removed the legacy SessionMembership from this file.
 export class CallMembership {
-    public static equal(a: CallMembership, b: CallMembership): boolean {
-        return deepCompare(a.membershipData, b.membershipData);
+    public static equal(a?: CallMembership, b?: CallMembership): boolean {
+        return deepCompare(a?.membershipData, b?.membershipData);
     }
-    private membershipData: SessionMembershipData;
 
+    private membershipData: MembershipData;
+
+    /** The parsed data from the Matrix event.
+     * To access checked eventId and sender from the matrixEvent.
+     * Class construction will fail if these values cannot get obtained. */
+    private readonly matrixEventData: { eventId: string; sender: string };
     public constructor(
-        private parentEvent: MatrixEvent,
-        data: any,
+        /** The Matrix event that this membership is based on */
+        private readonly matrixEvent: MatrixEvent,
+        data: IContent,
     ) {
+        const eventId = matrixEvent.getId();
+        const sender = matrixEvent.getSender();
+
+        if (eventId === undefined) throw new Error("parentEvent is missing eventId field");
+        if (sender === undefined) throw new Error("parentEvent is missing sender field");
+
         const sessionErrors: string[] = [];
-        if (!checkSessionsMembershipData(data, sessionErrors)) {
-            throw Error(
-                `unknown CallMembership data. Does not match MSC4143 call.member (${sessionErrors.join(" & ")}) events this could be a legacy membership event: (${data})`,
-            );
+        const rtcErrors: string[] = [];
+        if (checkSessionsMembershipData(data, sessionErrors)) {
+            this.membershipData = { kind: "session", data };
+        } else if (checkRtcMembershipData(data, rtcErrors, sender)) {
+            this.membershipData = { kind: "rtc", data };
         } else {
-            this.membershipData = data;
+            const details =
+                sessionErrors.length < rtcErrors.length
+                    ? `Does not match MSC4143 m.call.member:\n${sessionErrors.join("\n")}\n\n`
+                    : `Does not match MSC4143 m.rtc.member:\n${rtcErrors.join("\n")}\n\n`;
+            const json = "\nevent:\n" + JSON.stringify(data).replaceAll('"', "'");
+            throw Error(`unknown CallMembership data.\n` + details + json);
+        }
+        this.matrixEventData = { eventId, sender };
+    }
+
+    /** @deprecated use userId instead */
+    public get sender(): string {
+        return this.userId;
+    }
+    public get userId(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.user_id;
+            case "session":
+            default:
+                return this.matrixEventData.sender;
         }
     }
 
-    public get sender(): string | undefined {
-        return this.parentEvent.getSender();
-    }
-
-    public get eventId(): string | undefined {
-        return this.parentEvent.getId();
+    public get eventId(): string {
+        return this.matrixEventData.eventId;
     }
 
     /**
-     *  @deprecated Use sessionDescription.id instead.
+     * The ID of the MatrixRTC slot that this membership belongs to (format `{application}#{id}`).
+     * This is computed in case SessionMembershipData is used.
      */
-    public get callId(): string {
-        return this.membershipData.call_id;
+    public get slotId(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.slot_id;
+            case "session":
+            default:
+                return slotDescriptionToId({ application: this.application, id: data.call_id });
+        }
     }
 
     public get deviceId(): string {
-        return this.membershipData.device_id;
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.device_id;
+            case "session":
+            default:
+                return data.device_id;
+        }
     }
 
-    public get sessionDescription(): SessionDescription {
-        return {
-            application: this.membershipData.application,
-            id: this.membershipData.call_id,
-        };
+    public get callIntent(): RTCCallIntent | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc": {
+                const intent = data.application["m.call.intent"];
+                if (typeof intent === "string") {
+                    return intent;
+                }
+                logger.warn("RTC membership has invalid m.call.intent");
+                return undefined;
+            }
+            case "session":
+            default:
+                return data["m.call.intent"];
+        }
     }
 
-    public get application(): string | undefined {
-        return this.membershipData.application;
+    /**
+     * Parsed `slot_id` (format `{application}#{id}`) into its components (application and id).
+     */
+    public get slotDescription(): SlotDescription {
+        return slotIdToDescription(this.slotId);
     }
 
+    public get application(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.application.type;
+            case "session":
+            default:
+                return data.application;
+        }
+    }
+    public get applicationData(): { type: string; [key: string]: unknown } {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.application;
+            case "session":
+            default:
+                return { "type": data.application, "m.call.intent": data["m.call.intent"] };
+        }
+    }
+
+    /** @deprecated scope is not used and will be removed in future versions. replaced by application specific types.*/
     public get scope(): CallScope | undefined {
-        return this.membershipData.scope;
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                return data.scope;
+        }
     }
 
     public get membershipID(): string {
         // the createdTs behaves equivalent to the membershipID.
-        // we only need the field for the legacy member envents where we needed to update them
+        // we only need the field for the legacy member events where we needed to update them
         // synapse ignores sending state events if they have the same content.
-        return this.createdTs().toString();
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.id;
+            case "session":
+            default:
+                return (this.createdTs() ?? "").toString();
+        }
     }
 
     public createdTs(): number {
-        return this.membershipData.created_ts ?? this.parentEvent.getTs();
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                // TODO we need to read the referenced (relation) event if available to get the real created_ts
+                return this.matrixEvent.getTs();
+            case "session":
+            default:
+                return data.created_ts ?? this.matrixEvent.getTs();
+        }
     }
 
     /**
      * Gets the absolute expiry timestamp of the membership.
      * @returns The absolute expiry time of the membership as a unix timestamp in milliseconds or undefined if not applicable
      */
-    public getAbsoluteExpiry(): number {
-        // TODO: calculate this from the MatrixRTCSession join configuration directly
-        return this.createdTs() + (this.membershipData.expires ?? DEFAULT_EXPIRE_DURATION);
+    public getAbsoluteExpiry(): number | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                // TODO: calculate this from the MatrixRTCSession join configuration directly
+                return this.createdTs() + (data.expires ?? DEFAULT_EXPIRE_DURATION);
+        }
     }
 
     /**
      * @returns The number of milliseconds until the membership expires or undefined if applicable
      */
-    public getMsUntilExpiry(): number {
-        // Assume that local clock is sufficiently in sync with other clocks in the distributed system.
-        // We used to try and adjust for the local clock being skewed, but there are cases where this is not accurate.
-        // The current implementation allows for the local clock to be -infinity to +MatrixRTCSession.MEMBERSHIP_EXPIRY_TIME/2
-        return this.getAbsoluteExpiry() - Date.now();
+    public getMsUntilExpiry(): number | undefined {
+        const { kind } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                // Assume that local clock is sufficiently in sync with other clocks in the distributed system.
+                // We used to try and adjust for the local clock being skewed, but there are cases where this is not accurate.
+                // The current implementation allows for the local clock to be -infinity to +MatrixRTCSession.MEMBERSHIP_EXPIRY_TIME/2
+                return this.getAbsoluteExpiry()! - Date.now();
+        }
     }
 
     /**
      * @returns true if the membership has expired, otherwise false
      */
     public isExpired(): boolean {
-        return this.getMsUntilExpiry() <= 0;
+        const { kind } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return false;
+            case "session":
+            default:
+                return this.getMsUntilExpiry()! <= 0;
+        }
     }
 
-    public getPreferredFoci(): Focus[] {
-        return this.membershipData.foci_preferred;
+    /**
+     * ## RTC Membership
+     * Gets the primary transport to use for this RTC membership (m.rtc.member).
+     * This will return the primary transport that is used by this call membership to publish their media.
+     * Directly relates to the `rtc_transports` field.
+     *
+     * ## Legacy session membership
+     * In case of a legacy session membership (m.call.member) this will return the selected transport where
+     * media is published. How this selection happens depends on the `focus_active` field of the session membership.
+     * If the `focus_selection` is `oldest_membership` this will return the transport of the oldest membership
+     * in the room (based on the `created_ts` field of the session membership).
+     * If the `focus_selection` is `multi_sfu` it will return the first transport of the `foci_preferred` list.
+     * (`multi_sfu` is equivalent to how `m.rtc.member` `rtc_transports` work).
+     * @param oldestMembership For backwards compatibility with session membership (legacy). Unused in case of RTC membership.
+     * Always required to make the consumer not care if it deals with RTC or session memberships.
+     * @returns The transport this membership uses to publish media or undefined if no transport is available.
+     */
+    public getTransport(oldestMembership: CallMembership): Transport | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.rtc_transports[0];
+            case "session":
+                switch (data.focus_active.focus_selection) {
+                    case "multi_sfu":
+                        return data.foci_preferred[0];
+                    case "oldest_membership":
+                        if (CallMembership.equal(this, oldestMembership)) return data.foci_preferred[0];
+                        if (oldestMembership !== undefined) return oldestMembership.getTransport(oldestMembership);
+                        break;
+                }
+        }
+        return undefined;
     }
 
-    public getFocusSelection(): string | undefined {
-        const focusActive = this.membershipData.focus_active;
-        if (isLivekitFocusActive(focusActive)) {
-            return focusActive.focus_selection;
+    /**
+     * The focus_active filed of the session membership (m.call.member).
+     * @deprecated focus_active is not used and will be removed in future versions.
+     */
+    public getFocusActive(): LivekitFocusSelection | undefined {
+        const { kind, data } = this.membershipData;
+        if (kind === "session") return data.focus_active;
+        return undefined;
+    }
+    /**
+     * The value of the `rtc_transports` field for RTC memberships (m.rtc.member).
+     * Or the value of the `foci_preferred` field for legacy session memberships (m.call.member).
+     */
+    public get transports(): Transport[] {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.rtc_transports;
+            case "session":
+            default:
+                return data.foci_preferred;
         }
     }
 }

src/matrixrtc/EncryptionManager.ts

@@ -7,11 +7,6 @@ import { type CallMembership } from "./CallMembership.ts";
 import { type KeyTransportEventListener, KeyTransportEvents, type IKeyTransport } from "./IKeyTransport.ts";
 import { isMyMembership, type ParticipantId, type Statistics } from "./types.ts";
 import { getParticipantId } from "./utils.ts";
-import {
-    type EnabledTransports,
-    RoomAndToDeviceEvents,
-    RoomAndToDeviceTransport,
-} from "./RoomAndToDeviceKeyTransport.ts";
 
 /**
  * This interface is for testing and for making it possible to interchange the encryption manager.
@@ -119,10 +114,7 @@ export class EncryptionManager implements IEncryptionManager {
         this.manageMediaKeys = this.joinConfig?.manageMediaKeys ?? this.manageMediaKeys;
 
         this.transport.on(KeyTransportEvents.ReceivedKeys, this.onNewKeyReceived);
-        // Deprecate RoomKeyTransport: this can get removed.
-        if (this.transport instanceof RoomAndToDeviceTransport) {
-            this.transport.on(RoomAndToDeviceEvents.EnabledTransportsChanged, this.onTransportChanged);
-        }
+
         this.transport.start();
         if (this.joinConfig?.manageMediaKeys) {
             this.makeNewSenderKey();
@@ -315,10 +307,6 @@ export class EncryptionManager implements IEncryptionManager {
         }
     };
 
-    private onTransportChanged: (enabled: EnabledTransports) => void = () => {
-        this.requestSendCurrentKey();
-    };
-
     public onNewKeyReceived: KeyTransportEventListener = (userId, deviceId, keyBase64Encoded, index, timestamp) => {
         this.logger.debug(`Received key over key transport ${userId}:${deviceId} at index ${index}`);
         this.setEncryptionKey(userId, deviceId, index, keyBase64Encoded, timestamp);

src/matrixrtc/IMembershipManager.ts

@@ -15,8 +15,7 @@ limitations under the License.
 */
 
 import type { CallMembership } from "./CallMembership.ts";
-import type { Focus } from "./focus.ts";
-import type { Status } from "./types.ts";
+import type { RTCCallIntent, Status, Transport } from "./types.ts";
 import { type TypedEventEmitter } from "../models/typed-event-emitter.ts";
 
 export enum MembershipManagerEvent {
@@ -80,10 +79,13 @@ export interface IMembershipManager
     /**
      * Start sending all necessary events to make this user participate in the RTC session.
      * @param fociPreferred the list of preferred foci to use in the joined RTC membership event.
-     * @param fociActive the active focus to use in the joined RTC membership event.
+     * If multiSfuFocus is set, this is only needed if this client wants to publish to multiple transports simultaneously.
+     * @param multiSfuFocus the active focus to use in the joined RTC membership event. Setting this implies the
+     * membership manager will operate in a multi-SFU connection mode. If `undefined`, an `oldest_membership`
+     * transport selection will be used instead.
      * @throws can throw if it exceeds a configured maximum retry.
      */
-    join(fociPreferred: Focus[], fociActive?: Focus, onError?: (error: unknown) => void): void;
+    join(fociPreferred: Transport[], multiSfuFocus?: Transport, onError?: (error: unknown) => void): void;
     /**
      * Send all necessary events to make this user leave the RTC session.
      * @param timeout the maximum duration in ms until the promise is forced to resolve.
@@ -95,9 +97,10 @@ export interface IMembershipManager
      * Call this if the MatrixRTC session members have changed.
      */
     onRTCSessionMemberUpdate(memberships: CallMembership[]): Promise<void>;
+
     /**
-     * The used active focus in the currently joined session.
-     * @returns the used active focus in the currently joined session or undefined if not joined.
+     * Update the intent of a membership on the call (e.g. user is now providing a video feed)
+     * @param callIntent The new intent to set.
      */
-    getActiveFocus(): Focus | undefined;
+    updateCallIntent(callIntent: RTCCallIntent): Promise<void>;
 }

src/matrixrtc/LivekitFocus.ts

@@ -1,39 +0,0 @@
-/*
-Copyright 2023 New Vector Ltd
-
-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 Focus } from "./focus.ts";
-
-export interface LivekitFocusConfig extends Focus {
-    type: "livekit";
-    livekit_service_url: string;
-}
-
-export const isLivekitFocusConfig = (object: any): object is LivekitFocusConfig =>
-    object.type === "livekit" && "livekit_service_url" in object;
-
-export interface LivekitFocus extends LivekitFocusConfig {
-    livekit_alias: string;
-}
-
-export const isLivekitFocus = (object: any): object is LivekitFocus =>
-    isLivekitFocusConfig(object) && "livekit_alias" in object;
-
-export interface LivekitFocusActive extends Focus {
-    type: "livekit";
-    focus_selection: "oldest_membership";
-}
-export const isLivekitFocusActive = (object: any): object is LivekitFocusActive =>
-    object.type === "livekit" && "focus_selection" in object;

src/matrixrtc/LivekitTransport.ts

@@ -0,0 +1,46 @@
+/*
+Copyright 2025 New Vector Ltd
+
+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 Transport } from "./types.ts";
+
+export interface LivekitTransportConfig extends Transport {
+    type: "livekit";
+    livekit_service_url: string;
+}
+
+export const isLivekitTransportConfig = (object: any): object is LivekitTransportConfig =>
+    object.type === "livekit" && "livekit_service_url" in object;
+
+export interface LivekitTransport extends LivekitTransportConfig {
+    livekit_alias: string;
+}
+
+export const isLivekitTransport = (object: any): object is LivekitTransport =>
+    isLivekitTransportConfig(object) && "livekit_alias" in object;
+
+/**
+ * @deprecated, this is just needed for the old focus active / focus fields of a call membership.
+ * Not needed for new implementations.
+ */
+export interface LivekitFocusSelection extends Transport {
+    type: "livekit";
+    focus_selection: "oldest_membership" | "multi_sfu";
+}
+/**
+ * @deprecated see LivekitFocusSelection
+ */
+export const isLivekitFocusSelection = (object: any): object is LivekitFocusSelection =>
+    object.type === "livekit" && "focus_selection" in object;

src/matrixrtc/MatrixRTCSession.ts

@@ -24,31 +24,29 @@ 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 { type Focus } from "./focus.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 Statistics,
-    type RTCNotificationType,
-    type Status,
-    type IRTCNotificationContent,
-    type ICallNotifyContent,
+import type {
+    Statistics,
+    RTCNotificationType,
+    Status,
+    IRTCNotificationContent,
+    ICallNotifyContent,
+    RTCCallIntent,
+    Transport,
 } from "./types.ts";
-import { RoomKeyTransport } from "./RoomKeyTransport.ts";
 import {
     MembershipManagerEvent,
     type MembershipManagerEventHandlerMap,
     type IMembershipManager,
 } from "./IMembershipManager.ts";
 import { RTCEncryptionManager } from "./RTCEncryptionManager.ts";
-import {
-    RoomAndToDeviceEvents,
-    type RoomAndToDeviceEventsHandlerMap,
-    RoomAndToDeviceTransport,
-} from "./RoomAndToDeviceKeyTransport.ts";
-import { TypedReEmitter } from "../ReEmitter.ts";
 import { ToDeviceKeyTransport } from "./ToDeviceKeyTransport.ts";
+import { TypedReEmitter } from "../ReEmitter.ts";
+import { type MatrixEvent } from "../models/event.ts";
+import { RoomStickyEventsEvent, type RoomStickyEventsMap } from "../models/room-sticky-events.ts";
+import { RoomKeyTransport } from "./RoomKeyTransport.ts";
 
 /**
  * Events emitted by MatrixRTCSession
@@ -92,15 +90,27 @@ export interface SessionConfig {
      * @default `undefined` (no notification)
      */
     notificationType?: RTCNotificationType;
+
+    /**
+     * Determines the kind of call this will be.
+     */
+    callIntent?: RTCCallIntent;
 }
 
 /**
  * The session description is used to identify a session. Used in the state event.
  */
-export interface SessionDescription {
+export interface SlotDescription {
     id: string;
     application: string;
 }
+export function slotIdToDescription(slotId: string): SlotDescription {
+    const [application, id] = slotId.split("#");
+    return { application, id };
+}
+export function slotDescriptionToId(slotDescription: SlotDescription): string {
+    return `${slotDescription.application}#${slotDescription.id}`;
+}
 
 // The names follow these principles:
 // - we use the technical term delay if the option is related to delayed events.
@@ -110,14 +120,6 @@ export interface SessionDescription {
 // - 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.
@@ -179,6 +181,14 @@ export interface MembershipConfig {
      * but only applies to calls to the `_unstable_updateDelayedEvent` endpoint with a body of `{action:"restart"}`.)
      */
     delayedLeaveEventRestartLocalTimeoutMs?: number;
+
+    /**
+     * 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 {
@@ -224,18 +234,29 @@ 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.
  */
 export class MatrixRTCSession extends TypedEventEmitter<
-    MatrixRTCSessionEvent | RoomAndToDeviceEvents | MembershipManagerEvent,
-    MatrixRTCSessionEventHandlerMap & RoomAndToDeviceEventsHandlerMap & MembershipManagerEventHandlerMap
+    MatrixRTCSessionEvent | MembershipManagerEvent,
+    MatrixRTCSessionEventHandlerMap & MembershipManagerEventHandlerMap
 > {
     private membershipManager?: IMembershipManager;
     private encryptionManager?: IEncryptionManager;
-    // The session Id of the call, this is the call_id of the call Member event.
-    private _callId: string | undefined;
     private joinConfig?: SessionConfig;
     private logger: Logger;
 
@@ -273,53 +294,101 @@ export class MatrixRTCSession extends TypedEventEmitter<
      *
      * It can be undefined since the callId is only known once the first membership joins.
      * The callId is the property that, per definition, groups memberships into one call.
+     * @deprecated use `slotId` instead.
      */
     public get callId(): string | undefined {
-        return this._callId;
+        return this.slotDescription?.id;
+    }
+    /**
+     * The slotId of the call.
+     * `{application}#{appSpecificId}`
+     * It can be undefined since the slotId is only known once the first membership joins.
+     * The slotId is the property that, per definition, groups memberships into one call.
+     */
+    public get slotId(): string | undefined {
+        return slotDescriptionToId(this.slotDescription);
     }
 
     /**
      * Returns all the call memberships for a room that match the provided `sessionDescription`,
      * oldest first.
      *
-     * @deprecated Use `MatrixRTCSession.sessionMembershipsForRoom` instead.
+     * @deprecated Use `MatrixRTCSession.sessionMembershipsForSlot` instead.
      */
     public static callMembershipsForRoom(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState">,
+        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "_unstable_getStickyEvents">,
     ): CallMembership[] {
-        return MatrixRTCSession.sessionMembershipsForRoom(room, {
+        return MatrixRTCSession.sessionMembershipsForSlot(room, {
             id: "",
             application: "m.call",
         });
     }
 
     /**
-     * Returns all the call memberships for a room that match the provided `sessionDescription`,
-     * oldest first.
+     * @deprecated use `MatrixRTCSession.slotMembershipsForRoom` instead.
      */
     public static sessionMembershipsForRoom(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState">,
-        sessionDescription: SessionDescription,
+        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "_unstable_getStickyEvents">,
+        sessionDescription: SlotDescription,
+    ): CallMembership[] {
+        return this.sessionMembershipsForSlot(room, sessionDescription);
+    }
+
+    /**
+     * 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 sessionMembershipsForSlot(
+        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "_unstable_getStickyEvents">,
+        slotDescription: SlotDescription,
+        // default both true this implied we combine sticky and state events for the final call state
+        // (prefer sticky events in case of a duplicate)
+        { listenForStickyEvents, listenForMemberStateEvents }: SessionMembershipsForRoomOpts = {
+            listenForStickyEvents: true,
+            listenForMemberStateEvents: true,
+        },
     ): CallMembership[] {
         const logger = rootLogger.getChild(`[MatrixRTCSession ${room.roomId}]`);
-        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);
+        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 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 callMemberEvents = roomState.getStateEvents(EventType.GroupCallMemberPrefix);
 
         const callMemberships: CallMembership[] = [];
         for (const memberEvent of callMemberEvents) {
             const content = memberEvent.getContent();
-            const eventKeysCount = Object.keys(content).length;
+            // 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) continue;
 
             const membershipContents: any[] = [];
 
             // We first decide if its a MSC4143 event (per device state key)
-            if (eventKeysCount > 1 && "focus_active" in content) {
+            if (eventKeysCount > 1 && "application" in content) {
                 // We have a MSC4143 event membership event
                 membershipContents.push(content);
             } else if (eventKeysCount === 1 && "memberships" in content) {
@@ -329,12 +398,16 @@ export class MatrixRTCSession extends TypedEventEmitter<
             if (membershipContents.length === 0) continue;
 
             for (const membershipData of membershipContents) {
+                if (!("application" in membershipData)) {
+                    // This is a left membership event, ignore it here to not log warnings.
+                    continue;
+                }
                 try {
                     const membership = new CallMembership(memberEvent, membershipData);
 
-                    if (!deepCompare(membership.sessionDescription, sessionDescription)) {
+                    if (!deepCompare(membership.slotDescription, slotDescription)) {
                         logger.info(
-                            `Ignoring membership of user ${membership.sender} for a different session:  ${JSON.stringify(membership.sessionDescription)}`,
+                            `Ignoring membership of user ${membership.sender} for a different slot:  ${JSON.stringify(membership.slotDescription)}`,
                         );
                         continue;
                     }
@@ -373,26 +446,41 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * This method is an alias for `MatrixRTCSession.sessionForRoom` with
      * sessionDescription `{ id: "", application: "m.call" }`.
      *
-     * @deprecated Use `MatrixRTCSession.sessionForRoom` with sessionDescription `{ id: "", application: "m.call" }` instead.
+     * @deprecated Use `MatrixRTCSession.sessionForSlot` with sessionDescription `{ id: "", application: "m.call" }` instead.
      */
-    public static roomSessionForRoom(client: MatrixClient, room: Room): MatrixRTCSession {
-        const callMemberships = MatrixRTCSession.sessionMembershipsForRoom(room, { id: "", application: "m.call" });
+    public static roomSessionForRoom(
+        client: MatrixClient,
+        room: Room,
+        opts?: SessionMembershipsForRoomOpts,
+    ): MatrixRTCSession {
+        const callMemberships = MatrixRTCSession.sessionMembershipsForSlot(
+            room,
+            { id: "", application: "m.call" },
+            opts,
+        );
         return new MatrixRTCSession(client, room, callMemberships, { id: "", application: "m.call" });
     }
 
+    /**
+     * @deprecated Use `MatrixRTCSession.sessionForSlot` instead.
+     */
+    public static sessionForRoom(client: MatrixClient, room: Room, slotDescription: SlotDescription): MatrixRTCSession {
+        return this.sessionForSlot(client, room, slotDescription);
+    }
+
     /**
      * Return the MatrixRTC session for the room.
      * This returned session can be used to find out if there are active sessions
-     * for the requested room and `sessionDescription`.
+     * for the requested room and `slotDescription`.
      */
-    public static sessionForRoom(
+    public static sessionForSlot(
         client: MatrixClient,
         room: Room,
-        sessionDescription: SessionDescription,
+        slotDescription: SlotDescription,
+        opts?: SessionMembershipsForRoomOpts,
     ): MatrixRTCSession {
-        const callMemberships = MatrixRTCSession.sessionMembershipsForRoom(room, sessionDescription);
-
-        return new MatrixRTCSession(client, room, callMemberships, sessionDescription);
+        const callMemberships = MatrixRTCSession.sessionMembershipsForSlot(room, slotDescription, opts);
+        return new MatrixRTCSession(client, room, callMemberships, slotDescription);
     }
 
     /**
@@ -422,10 +510,12 @@ export class MatrixRTCSession extends TypedEventEmitter<
             MatrixClient,
             | "getUserId"
             | "getDeviceId"
+            | "sendEvent"
             | "sendStateEvent"
             | "_unstable_sendDelayedStateEvent"
             | "_unstable_updateDelayedEvent"
-            | "sendEvent"
+            | "_unstable_sendStickyEvent"
+            | "_unstable_sendStickyDelayedEvent"
             | "cancelPendingEvent"
             | "encryptAndSendToDevice"
             | "off"
@@ -438,20 +528,21 @@ export class MatrixRTCSession extends TypedEventEmitter<
         >,
         public memberships: CallMembership[],
         /**
-         * The session description is used to define the exact session this object is tracking.
-         * A session is distinct from another session if one of those properties differ: `roomSubset.roomId`, `sessionDescription.application`, `sessionDescription.id`.
+         * The slot description is a virtual address where participants are allowed to meet.
+         * This session will only manage memberships that match this slot description.
+         * Sessions are distinct if any of those properties are distinct: `roomSubset.roomId`, `slotDescription.application`, `slotDescription.id`.
          */
-        public readonly sessionDescription: SessionDescription,
+        public readonly slotDescription: SlotDescription,
     ) {
         super();
         this.logger = rootLogger.getChild(`[MatrixRTCSession ${roomSubset.roomId}]`);
-        this._callId = memberships[0]?.sessionDescription.id;
         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.
@@ -471,10 +562,12 @@ 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
+        MatrixRTCSessionEvent | MembershipManagerEvent,
+        MatrixRTCSessionEventHandlerMap & MembershipManagerEventHandlerMap
     >(this);
 
     /**
@@ -484,28 +577,32 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * This will not subscribe to updates: remember to call subscribe() separately if
      * desired.
      * This method will return immediately and the session will be joined in the background.
-     *
-     * @param fociActive - The object representing the active focus. (This depends on the focus type.)
-     * @param fociPreferred - The list of preferred foci this member proposes to use/knows/has access to.
-     *                        For the livekit case this is a list of foci generated from the homeserver well-known, the current rtc session,
-     *                        or optionally other room members homeserver well known.
+     * @param fociPreferred the list of preferred foci to use in the joined RTC membership event.
+     * If multiSfuFocus is set, this is only needed if this client wants to publish to multiple transports simultaneously.
+     * @param multiSfuFocus the active focus to use in the joined RTC membership event. Setting this implies the
+     * membership manager will operate in a multi-SFU connection mode. If `undefined`, an `oldest_membership`
+     * transport selection will be used instead.
      * @param joinConfig - Additional configuration for the joined session.
      */
-    public joinRoomSession(fociPreferred: Focus[], fociActive?: Focus, joinConfig?: JoinSessionConfig): void {
+    public joinRoomSession(
+        fociPreferred: Transport[],
+        multiSfuFocus?: Transport,
+        joinConfig?: JoinSessionConfig,
+    ): void {
         if (this.isJoined()) {
             this.logger.info(`Already joined to session in room ${this.roomSubset.roomId}: ignoring join call`);
             return;
         } else {
             // Create MembershipManager and pass the RTCSession logger (with room id info)
-
-            this.membershipManager = new MembershipManager(
-                joinConfig,
-                this.roomSubset,
-                this.client,
-                () => this.getOldestMembership(),
-                this.sessionDescription,
-                this.logger,
-            );
+            this.membershipManager = joinConfig?.unstableSendStickyEvents
+                ? 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,
@@ -518,13 +615,7 @@ export class MatrixRTCSession extends TypedEventEmitter<
                 this.logger.info("Using to-device with room fallback transport for encryption keys");
                 const [uId, dId] = [this.client.getUserId()!, this.client.getDeviceId()!];
                 const [room, client, statistics] = [this.roomSubset, this.client, this.statistics];
-                // Deprecate RoomKeyTransport: only ToDeviceKeyTransport is needed once deprecated
-                const roomKeyTransport = new RoomKeyTransport(room, client, statistics);
-                const toDeviceTransport = new ToDeviceKeyTransport(uId, dId, room.roomId, client, statistics);
-                transport = new RoomAndToDeviceTransport(toDeviceTransport, roomKeyTransport, this.logger);
-
-                // Expose the changes so the ui can display the currently used transport.
-                this.reEmitter.reEmit(transport, [RoomAndToDeviceEvents.EnabledTransportsChanged]);
+                const transport = new ToDeviceKeyTransport(uId, dId, room.roomId, client, statistics);
                 this.encryptionManager = new RTCEncryptionManager(
                     this.client.getUserId()!,
                     this.client.getDeviceId()!,
@@ -565,7 +656,7 @@ export class MatrixRTCSession extends TypedEventEmitter<
         this.pendingNotificationToSend = this.joinConfig?.notificationType;
 
         // Join!
-        this.membershipManager!.join(fociPreferred, fociActive, (e) => {
+        this.membershipManager!.join(fociPreferred, multiSfuFocus, (e) => {
             this.logger.error("MembershipManager encountered an unrecoverable error: ", e);
             this.emit(MatrixRTCSessionEvent.MembershipManagerError, e);
             this.emit(MatrixRTCSessionEvent.JoinStateChanged, this.isJoined());
@@ -600,32 +691,51 @@ export class MatrixRTCSession extends TypedEventEmitter<
 
         return await leavePromise;
     }
-
     /**
-     * Get the active focus from the current CallMemberState event
-     * @returns The focus that is currently in use to connect to this session. This is undefined
-     * if the client is not connected to this session.
+     * This returns the focus in use by the oldest membership.
+     * Do not use since this might be just the focus for the oldest membership. others might use a different focus.
+     * @deprecated use `member.getTransport(session.getOldestMembership())` instead for the specific member you want to get the focus for.
      */
-    public getActiveFocus(): Focus | undefined {
-        return this.membershipManager?.getActiveFocus();
+    public getFocusInUse(): Transport | undefined {
+        const oldestMembership = this.getOldestMembership();
+        return oldestMembership?.getTransport(oldestMembership);
     }
 
+    /**
+     * The used focusActive of the oldest membership (to find out the selection type multi-sfu or oldest membership active focus)
+     * @deprecated does not work with m.rtc.member. Do not rely on it.
+     */
+    public getActiveFocus(): Transport | undefined {
+        return this.getOldestMembership()?.getFocusActive();
+    }
     public getOldestMembership(): CallMembership | undefined {
         return this.memberships[0];
     }
 
     /**
-     * This method is used when the user is not yet connected to the Session but wants to know what focus
-     * the users in the session are using to make a decision how it wants/should connect.
+     * Get the call intent for the current call, based on what members are advertising. If one or more
+     * members disagree on the current call intent, or nobody specifies one then `undefined` is returned.
      *
-     * See also `getActiveFocus`
-     * @returns The focus which should be used when joining this session.
+     * If all members that specify a call intent agree, that value is returned.
+     * @returns A call intent, or `undefined` if no consensus or not given.
      */
-    public getFocusInUse(): Focus | undefined {
-        const oldestMembership = this.getOldestMembership();
-        if (oldestMembership?.getFocusSelection() === "oldest_membership") {
-            return oldestMembership.getPreferredFoci()[0];
+    public getConsensusCallIntent(): RTCCallIntent | undefined {
+        const getFirstCallIntent = this.memberships.find((m) => !!m.callIntent)?.callIntent;
+        if (!getFirstCallIntent) {
+            return undefined;
         }
+        if (this.memberships.every((m) => !m.callIntent || m.callIntent === getFirstCallIntent)) {
+            return getFirstCallIntent;
+        }
+        return undefined;
+    }
+
+    public async updateCallIntent(callIntent: RTCCallIntent): Promise<void> {
+        const myMembership = this.membershipManager?.ownMembership;
+        if (!myMembership) {
+            throw Error("Not connected yet");
+        }
+        await this.membershipManager?.updateCallIntent(callIntent);
     }
 
     /**
@@ -665,9 +775,17 @@ export class MatrixRTCSession extends TypedEventEmitter<
     }
 
     /**
-     * Sends a notification corresponding to the configured notify type.
+     * Sends notification events to indiciate the call has started.
+     * Note: This does not return a promise, instead scheduling the notification events to be sent.
+     * @param parentEventId Event id linking to your RTC call membership event.
+     * @param notificationType The type of notification to send
+     * @param callIntent The type of call this is (e.g. "audio").
      */
-    private sendCallNotify(parentEventId: string, notificationType: RTCNotificationType): void {
+    private sendCallNotify(
+        parentEventId: string,
+        notificationType: RTCNotificationType,
+        callIntent?: RTCCallIntent,
+    ): void {
         const sendLegacyNotificationEvent = async (): Promise<{
             response: ISendEventResponse;
             content: ICallNotifyContent;
@@ -695,6 +813,9 @@ export class MatrixRTCSession extends TypedEventEmitter<
                 "sender_ts": Date.now(),
                 "lifetime": 30_000, // 30 seconds
             };
+            if (callIntent) {
+                content["m.call.intent"] = callIntent;
+            }
             const response = await this.client.sendEvent(this.roomSubset.roomId, EventType.RTCNotification, content);
             return { response, content };
         };
@@ -714,10 +835,27 @@ export class MatrixRTCSession extends TypedEventEmitter<
     /**
      * Call this when the Matrix room members have changed.
      */
-    public onRoomMemberUpdate = (): void => {
+    private readonly onRoomMemberUpdate = (): 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,
+            )
+        ) {
+            this.recalculateSessionMembers();
+        }
+    };
+
     /**
      * Call this when something changed that may impacts the current MatrixRTC members in this session.
      */
@@ -734,9 +872,7 @@ export class MatrixRTCSession extends TypedEventEmitter<
      */
     private recalculateSessionMembers = (): void => {
         const oldMemberships = this.memberships;
-        this.memberships = MatrixRTCSession.sessionMembershipsForRoom(this.room, this.sessionDescription);
-
-        this._callId = this._callId ?? this.memberships[0]?.sessionDescription.id;
+        this.memberships = MatrixRTCSession.sessionMembershipsForSlot(this.room, this.slotDescription);
 
         const changed =
             oldMemberships.length != this.memberships.length ||
@@ -757,7 +893,11 @@ export class MatrixRTCSession extends TypedEventEmitter<
                 // If we're the first member in the call, we're responsible for
                 // sending the notification event
                 if (ownMembership.eventId && this.joinConfig?.notificationType) {
-                    this.sendCallNotify(ownMembership.eventId, this.joinConfig.notificationType);
+                    this.sendCallNotify(
+                        ownMembership.eventId,
+                        this.joinConfig.notificationType,
+                        ownMembership.callIntent,
+                    );
                 } else {
                     this.logger.warn("Own membership eventId is undefined, cannot send call notification");
                 }
@@ -765,6 +905,8 @@ 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

@@ -18,9 +18,9 @@ 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 SessionDescription } from "./MatrixRTCSession.ts";
+import { MatrixRTCSession, type SlotDescription } from "./MatrixRTCSession.ts";
 import { EventType } from "../@types/event.ts";
 
 export enum MatrixRTCSessionManagerEvents {
@@ -56,7 +56,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
     public constructor(
         rootLogger: Logger,
         private client: MatrixClient,
-        private readonly sessionDescription: SessionDescription = { id: "", application: "m.call" }, // Default to the Matrix Call application
+        private readonly slotDescription: SlotDescription = { application: "m.call", id: "" }, // Default to the Matrix Call application
     ) {
         super();
         this.logger = rootLogger.getChild("[MatrixRTCSessionManager]");
@@ -66,13 +66,14 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         // We shouldn't need to null-check here, but matrix-client.spec.ts mocks getRooms
         // returning nothing, and breaks tests if you change it to return an empty array :'(
         for (const room of this.client.getRooms() ?? []) {
-            const session = MatrixRTCSession.sessionForRoom(this.client, room, this.sessionDescription);
+            const session = MatrixRTCSession.sessionForRoom(this.client, room, this.slotDescription);
             if (session.memberships.length > 0) {
                 this.roomSessions.set(room.roomId, session);
             }
         }
 
         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);
     }
 
@@ -102,7 +104,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         if (!this.roomSessions.has(room.roomId)) {
             this.roomSessions.set(
                 room.roomId,
-                MatrixRTCSession.sessionForRoom(this.client, room, this.sessionDescription),
+                MatrixRTCSession.sessionForRoom(this.client, room, this.slotDescription),
             );
         }
 
@@ -113,16 +115,28 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         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;
+
+        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) {
-            this.refreshRoom(room);
-        }
+        this.refreshRoom(room);
     };
 
     private refreshRoom(room: Room): void {

src/matrixrtc/MembershipManager.ts

@@ -15,20 +15,33 @@ limitations under the License.
 */
 import { AbortError } from "p-retry";
 
-import { EventType } from "../@types/event.ts";
-import { UpdateDelayedEventAction } from "../@types/requests.ts";
-import { type MatrixClient } from "../client.ts";
-import { UnsupportedDelayedEventsEndpointError } from "../errors.ts";
+import { EventType, RelationType } from "../@types/event.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";
 import { type Room } from "../models/room.ts";
-import { type CallMembership, DEFAULT_EXPIRE_DURATION, type SessionMembershipData } from "./CallMembership.ts";
-import { type Focus } from "./focus.ts";
-import { isMyMembership, Status } from "./types.ts";
-import { isLivekitFocusActive } from "./LivekitFocus.ts";
-import { type SessionDescription, type MembershipConfig } from "./MatrixRTCSession.ts";
+import {
+    type CallMembership,
+    DEFAULT_EXPIRE_DURATION,
+    type RtcMembershipData,
+    type SessionMembershipData,
+} from "./CallMembership.ts";
+import { type Transport, isMyMembership, type RTCCallIntent, Status } from "./types.ts";
+import {
+    type SlotDescription,
+    type MembershipConfig,
+    type SessionConfig,
+    slotDescriptionToId,
+} from "./MatrixRTCSession.ts";
 import { ActionScheduler, type ActionUpdate } from "./MembershipManagerActionScheduler.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
+import { UnsupportedDelayedEventsEndpointError } from "../errors.ts";
 import {
     MembershipManagerEvent,
     type IMembershipManager,
@@ -36,12 +49,11 @@ import {
 } from "./IMembershipManager.ts";
 
 /* MembershipActionTypes:
-                           
 On Join:  ───────────────┐   ┌───────────────(1)───────────┐
                          ▼   ▼                             │
                    ┌────────────────┐                      │
                    │SendDelayedEvent│ ──────(2)───┐        │
-                   └────────────────┘             │        │ 
+                   └────────────────┘             │        │
                            │(3)                   │        │
                            ▼                      │        │
                     ┌─────────────┐               │        │
@@ -52,9 +64,9 @@ On Join:  ───────────────┐   ┌─────
 ┌────────────┐  │                  │ ┌───────────────────┐ │
 │UpdateExpiry│ (s)                (s)|RestartDelayedEvent│ │
 └────────────┘  │                  │ └───────────────────┘ │
-          │     │                  │      │        │       │       
-          └─────┘                  └──────┘        └───────┘ 
-     
+          │     │                  │      │        │       │
+          └─────┘                  └──────┘        └───────┘
+
 On Leave: ─────────  STOP ALL ABOVE
                            ▼
             ┌────────────────────────────────┐
@@ -77,6 +89,12 @@ 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
@@ -137,6 +155,23 @@ 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:
@@ -155,7 +190,8 @@ export class MembershipManager
     implements IMembershipManager
 {
     private activated = false;
-    private logger: Logger;
+    private readonly logger: Logger;
+    protected callIntent: RTCCallIntent | undefined;
 
     public isActivated(): boolean {
         return this.activated;
@@ -168,18 +204,21 @@ export class MembershipManager
     /**
      * Puts the MembershipManager in a state where it tries to be joined.
      * It will send delayed events and membership events
-     * @param fociPreferred
-     * @param focusActive
+     * @param fociPreferred the list of preferred foci to use in the joined RTC membership event.
+     * If multiSfuFocus is set, this is only needed if this client wants to publish to multiple transports simultaneously.
+     * @param multiSfuFocus the active focus to use in the joined RTC membership event. Setting this implies the
+     * membership manager will operate in a multi-SFU connection mode. If `undefined`, an `oldest_membership`
+     * transport selection will be used instead.
      * @param onError This will be called once the membership manager encounters an unrecoverable error.
      * This should bubble up the the frontend to communicate that the call does not work in the current environment.
      */
-    public join(fociPreferred: Focus[], focusActive?: Focus, onError?: (error: unknown) => void): void {
+    public join(fociPreferred: Transport[], multiSfuFocus?: Transport, onError?: (error: unknown) => void): void {
         if (this.scheduler.running) {
             this.logger.error("MembershipManager is already running. Ignoring join request.");
             return;
         }
         this.fociPreferred = fociPreferred;
-        this.focusActive = focusActive;
+        this.rtcTransport = multiSfuFocus;
         this.leavePromiseResolvers = undefined;
         this.activated = true;
         this.oldStatus = this.status;
@@ -230,7 +269,10 @@ export class MembershipManager
 
     private leavePromiseResolvers?: PromiseWithResolvers<boolean>;
 
-    public async onRTCSessionMemberUpdate(memberships: CallMembership[]): Promise<void> {
+    public onRTCSessionMemberUpdate(memberships: CallMembership[]): Promise<void> {
+        if (!this.isActivated()) {
+            return Promise.resolve();
+        }
         const userId = this.client.getUserId();
         const deviceId = this.client.getDeviceId();
         if (!userId || !deviceId) {
@@ -239,7 +281,7 @@ export class MembershipManager
         }
         this._ownMembership = memberships.find((m) => isMyMembership(m, userId, deviceId));
 
-        if (this.isActivated() && !this._ownMembership) {
+        if (!this._ownMembership) {
             // If one of these actions are scheduled or are getting inserted in the next iteration, we should already
             // take care of our missing membership.
             const sendingMembershipActions = [
@@ -262,23 +304,16 @@ export class MembershipManager
         return Promise.resolve();
     }
 
-    public getActiveFocus(): Focus | undefined {
-        if (this.focusActive) {
-            // A livekit active focus
-            if (isLivekitFocusActive(this.focusActive)) {
-                if (this.focusActive.focus_selection === "oldest_membership") {
-                    const oldestMembership = this.getOldestMembership();
-                    return oldestMembership?.getPreferredFoci()[0];
-                }
-            } else {
-                this.logger.warn("Unknown own ActiveFocus type. This makes it impossible to connect to an SFU.");
-            }
-        } else {
-            // We do not understand the membership format (could be legacy). We default to oldestMembership
-            // Once there are other methods this is a hard error!
-            const oldestMembership = this.getOldestMembership();
-            return oldestMembership?.getPreferredFoci()[0];
+    public async updateCallIntent(callIntent: RTCCallIntent): Promise<void> {
+        if (!this.activated || !this.ownMembership) {
+            throw Error("You cannot update your intent before joining the call");
         }
+        if (this.ownMembership.callIntent === callIntent) {
+            return; // No-op
+        }
+        this.callIntent = callIntent;
+        // Kick off a new membership event as a result.
+        await this.sendJoinEvent();
     }
 
     /**
@@ -286,21 +321,12 @@ export class MembershipManager
      * @param joinConfig
      * @param room
      * @param client
-     * @param getOldestMembership
      */
     public constructor(
-        private joinConfig: MembershipConfig | undefined,
-        private room: Pick<Room, "getLiveTimeline" | "roomId" | "getVersion">,
-        private client: Pick<
-            MatrixClient,
-            | "getUserId"
-            | "getDeviceId"
-            | "sendStateEvent"
-            | "_unstable_sendDelayedStateEvent"
-            | "_unstable_updateDelayedEvent"
-        >,
-        private getOldestMembership: () => CallMembership | undefined,
-        public readonly sessionDescription: SessionDescription,
+        private readonly joinConfig: (SessionConfig & MembershipConfig) | undefined,
+        protected readonly room: Pick<Room, "roomId" | "getVersion">,
+        protected readonly client: MembershipManagerClient,
+        public readonly slotDescription: SlotDescription,
         parentLogger?: Logger,
     ) {
         super();
@@ -309,8 +335,11 @@ export class MembershipManager
         if (userId === null) throw Error("Missing userId in client");
         if (deviceId === null) throw Error("Missing deviceId in client");
         this.deviceId = deviceId;
-        this.stateKey = this.makeMembershipStateKey(userId, deviceId);
+        // this needs to become a uuid so that consecutive join/leaves result in a key rotation.
+        // we keep it as a string for now for backwards compatibility.
+        this.memberId = this.makeMembershipStateKey(userId, deviceId);
         this.state = MembershipManager.defaultState;
+        this.callIntent = joinConfig?.callIntent;
         this.scheduler = new ActionScheduler((type): Promise<ActionUpdate> => {
             if (this.oldStatus) {
                 // we put this at the beginning of the actions scheduler loop handle callback since it is a loop this
@@ -353,10 +382,11 @@ export class MembershipManager
         };
     }
     // Membership Event static parameters:
-    private deviceId: string;
-    private stateKey: string;
-    private fociPreferred?: Focus[];
-    private focusActive?: Focus;
+    protected deviceId: 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[];
 
     // Config:
     private delayedLeaveEventDelayMsOverride?: number;
@@ -371,9 +401,13 @@ 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 {
@@ -385,10 +419,10 @@ export class MembershipManager
     private get maximumNetworkErrorRetryCount(): number {
         return this.joinConfig?.maximumNetworkErrorRetryCount ?? 10;
     }
-
     private get delayedLeaveEventRestartLocalTimeoutMs(): number {
         return this.joinConfig?.delayedLeaveEventRestartLocalTimeoutMs ?? 2000;
     }
+
     // LOOP HANDLER:
     private async membershipLoopHandler(type: MembershipActionType): Promise<ActionUpdate> {
         switch (type) {
@@ -443,22 +477,23 @@ 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 async 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 await this.client
-            ._unstable_sendDelayedStateEvent(
-                this.room.roomId,
-                {
-                    delay: this.delayedLeaveEventDelayMs,
-                },
-                EventType.GroupCallMemberPrefix,
-                {}, // leave event
-                this.stateKey,
-            )
+        return await this.clientSendDelayedDisconnectMembership()
             .then((response) => {
                 this.state.expectedServerDelayLeaveTs = Date.now() + this.delayedLeaveEventDelayMs;
                 this.setAndEmitProbablyLeft(false);
@@ -482,7 +517,7 @@ 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) {
@@ -638,14 +673,19 @@ export class MembershipManager
             });
     }
 
+    protected clientSendMembership: (
+        myMembership: RtcMembershipData | SessionMembershipData | EmptyObject,
+    ) => Promise<ISendEventResponse> = (myMembership) => {
+        return this.client.sendStateEvent(
+            this.room.roomId,
+            EventType.GroupCallMemberPrefix,
+            myMembership as EmptyObject | SessionMembershipData,
+            this.memberId,
+        );
+    };
+
     private async sendJoinEvent(): Promise<ActionUpdate> {
-        return await this.client
-            .sendStateEvent(
-                this.room.roomId,
-                EventType.GroupCallMemberPrefix,
-                this.makeMyMembership(this.membershipEventExpiryMs),
-                this.stateKey,
-            )
+        return await this.clientSendMembership(this.makeMyMembership(this.membershipEventExpiryMs))
             .then(() => {
                 this.setAndEmitProbablyLeft(false);
                 this.state.startTime = Date.now();
@@ -685,13 +725,9 @@ export class MembershipManager
 
     private async updateExpiryOnJoinedEvent(): Promise<ActionUpdate> {
         const nextExpireUpdateIteration = this.state.expireUpdateIterations + 1;
-        return await this.client
-            .sendStateEvent(
-                this.room.roomId,
-                EventType.GroupCallMemberPrefix,
-                this.makeMyMembership(this.membershipEventExpiryMs * nextExpireUpdateIteration),
-                this.stateKey,
-            )
+        return await this.clientSendMembership(
+            this.makeMyMembership(this.membershipEventExpiryMs * nextExpireUpdateIteration),
+        )
             .then(() => {
                 // Success, we reset retries and schedule update.
                 this.resetRateLimitCounter(MembershipActionType.UpdateExpiry);
@@ -713,8 +749,7 @@ export class MembershipManager
             });
     }
     private async sendFallbackLeaveEvent(): Promise<ActionUpdate> {
-        return await this.client
-            .sendStateEvent(this.room.roomId, EventType.GroupCallMemberPrefix, {}, this.stateKey)
+        return await this.clientSendMembership({})
             .then(() => {
                 this.resetRateLimitCounter(MembershipActionType.SendLeaveEvent);
                 this.state.hasMemberStateEvent = false;
@@ -729,7 +764,7 @@ export class MembershipManager
 
     // HELPERS
     private makeMembershipStateKey(localUserId: string, localDeviceId: string): string {
-        const stateKey = `${localUserId}_${localDeviceId}_${this.sessionDescription.application}${this.sessionDescription.id}`;
+        const stateKey = `${localUserId}_${localDeviceId}_${this.slotDescription.application}${this.slotDescription.id}`;
         if (/^org\.matrix\.msc(3757|3779)\b/.exec(this.room.getVersion())) {
             return stateKey;
         } else {
@@ -740,16 +775,28 @@ export class MembershipManager
     /**
      * Constructs our own membership
      */
-    private makeMyMembership(expires: number): SessionMembershipData {
+    protected makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
+        const ownMembership = this.ownMembership;
+
+        const focusObjects =
+            this.rtcTransport === undefined
+                ? {
+                      focus_active: { type: "livekit", focus_selection: "oldest_membership" } as const,
+                      foci_preferred: this.fociPreferred ?? [],
+                  }
+                : {
+                      focus_active: { type: "livekit", focus_selection: "multi_sfu" } as const,
+                      foci_preferred: [this.rtcTransport, ...(this.fociPreferred ?? [])],
+                  };
         return {
-            // TODO: use the new format for m.rtc.member events where call_id becomes session.id
-            application: this.sessionDescription.application,
-            call_id: this.sessionDescription.id,
-            scope: "m.room",
-            device_id: this.deviceId,
+            "application": this.slotDescription.application,
+            "call_id": this.slotDescription.id,
+            "scope": "m.room",
+            "device_id": this.deviceId,
             expires,
-            focus_active: { type: "livekit", focus_selection: "oldest_membership" },
-            foci_preferred: this.fociPreferred ?? [],
+            "m.call.intent": this.callIntent,
+            ...focusObjects,
+            ...(ownMembership !== undefined ? { created_ts: ownMembership.createdTs() } : undefined),
         };
     }
 
@@ -785,7 +832,7 @@ export class MembershipManager
         return false;
     }
 
-    private actionUpdateFromErrors(
+    protected actionUpdateFromErrors(
         error: unknown,
         type: MembershipActionType,
         method: string,
@@ -833,7 +880,7 @@ 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 });
     }
 
     /**
@@ -977,14 +1024,68 @@ export class MembershipManager
     }
 }
 
-function createInsertActionUpdate(type: MembershipActionType, offset?: number): ActionUpdate {
-    return {
-        insert: [{ ts: Date.now() + (offset ?? 0), type }],
-    };
-}
+/**
+ * Implementation of the Membership manager that uses sticky events
+ * 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 {
-    return {
-        replace: [{ ts: Date.now() + (offset ?? 0), type }],
+    protected clientSendDelayedDisconnectMembership: () => Promise<SendDelayedEventResponse> = () =>
+        this.clientWithSticky._unstable_sendStickyDelayedEvent(
+            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,
+        };
+    }
 }

src/matrixrtc/RTCEncryptionManager.ts

@@ -29,11 +29,6 @@ import type {
     Statistics,
 } from "./types.ts";
 import { getParticipantId, OutdatedKeyFilter } from "./utils.ts";
-import {
-    type EnabledTransports,
-    RoomAndToDeviceEvents,
-    RoomAndToDeviceTransport,
-} from "./RoomAndToDeviceKeyTransport.ts";
 
 /**
  * RTCEncryptionManager is used to manage the encryption keys for a call.
@@ -137,10 +132,6 @@ export class RTCEncryptionManager implements IEncryptionManager {
         this.useKeyDelay = joinConfig?.useKeyDelay ?? 1000;
         this.keyRotationGracePeriodMs = joinConfig?.keyRotationGracePeriodMs ?? 10_000;
         this.transport.on(KeyTransportEvents.ReceivedKeys, this.onNewKeyReceived);
-        // Deprecate RoomKeyTransport: this can get removed.
-        if (this.transport instanceof RoomAndToDeviceTransport) {
-            this.transport.on(RoomAndToDeviceEvents.EnabledTransportsChanged, this.onTransportChanged);
-        }
 
         this.transport.start();
     }
@@ -151,29 +142,6 @@ export class RTCEncryptionManager implements IEncryptionManager {
         this.participantKeyRings.clear();
     }
 
-    // Temporary for backwards compatibility
-    // TODO: Remove this in the future
-    private onTransportChanged: (enabled: EnabledTransports) => void = () => {
-        this.logger?.info("Transport change detected, restarting key distribution");
-        if (this.currentKeyDistributionPromise) {
-            this.currentKeyDistributionPromise
-                .then(() => {
-                    if (this.outboundSession) {
-                        this.outboundSession.sharedWith = [];
-                        this.ensureKeyDistribution();
-                    }
-                })
-                .catch((e) => {
-                    this.logger?.error("Failed to restart key distribution", e);
-                });
-        } else {
-            if (this.outboundSession) {
-                this.outboundSession.sharedWith = [];
-                this.ensureKeyDistribution();
-            }
-        }
-    };
-
     /**
      * Will ensure that a new key is distributed and used to encrypt our media.
      * If there is already a key distribution in progress, it will schedule a new distribution round just after the current one is completed.

src/matrixrtc/RoomAndToDeviceKeyTransport.ts

@@ -1,131 +0,0 @@
-/*
-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 { logger as rootLogger, type Logger } from "../logger.ts";
-import { KeyTransportEvents, type KeyTransportEventsHandlerMap, type IKeyTransport } from "./IKeyTransport.ts";
-import type { RoomKeyTransport } from "./RoomKeyTransport.ts";
-import { NotSupportedError, type ToDeviceKeyTransport } from "./ToDeviceKeyTransport.ts";
-import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
-import { type ParticipantDeviceInfo } from "./types.ts";
-
-// Deprecate RoomAndToDeviceTransport: This whole class is only a stop gap until we remove RoomKeyTransport.
-export interface EnabledTransports {
-    toDevice: boolean;
-    room: boolean;
-}
-
-export enum RoomAndToDeviceEvents {
-    EnabledTransportsChanged = "enabled_transports_changed",
-}
-export type RoomAndToDeviceEventsHandlerMap = {
-    [RoomAndToDeviceEvents.EnabledTransportsChanged]: (enabledTransports: EnabledTransports) => void;
-};
-/**
- * A custom transport that subscribes to room key events (via `RoomKeyTransport`) and to device key events (via: `ToDeviceKeyTransport`)
- * The public setEnabled method allows to turn one or the other on or off on the fly.
- * It will emit `RoomAndToDeviceEvents.EnabledTransportsChanged` if the enabled transport changes to allow comminitcating this to
- * the user in the ui.
- *
- * Since it will always subscribe to both (room and to device) but only emit for the enabled ones, it can detect
- * if a room key event was received and autoenable it.
- */
-export class RoomAndToDeviceTransport
-    extends TypedEventEmitter<
-        KeyTransportEvents | RoomAndToDeviceEvents,
-        KeyTransportEventsHandlerMap & RoomAndToDeviceEventsHandlerMap
-    >
-    implements IKeyTransport
-{
-    private readonly logger: Logger;
-    private _enabled: EnabledTransports = { toDevice: true, room: false };
-    public constructor(
-        private toDeviceTransport: ToDeviceKeyTransport,
-        private roomKeyTransport: RoomKeyTransport,
-        parentLogger?: Logger,
-    ) {
-        super();
-        this.logger = (parentLogger ?? rootLogger).getChild(`[RoomAndToDeviceTransport]`);
-        // update parent loggers for the sub transports so filtering for `RoomAndToDeviceTransport` contains their logs too
-        this.toDeviceTransport.setParentLogger(this.logger);
-        this.roomKeyTransport.setParentLogger(this.logger);
-
-        this.roomKeyTransport.on(KeyTransportEvents.ReceivedKeys, (...props) => {
-            // Turn on the room transport if we receive a roomKey from another participant
-            // and disable the toDevice transport.
-            if (!this._enabled.room) {
-                this.logger.debug("Received room key, enabling room key transport, disabling toDevice transport");
-                this.setEnabled({ toDevice: false, room: true });
-            }
-            this.emit(KeyTransportEvents.ReceivedKeys, ...props);
-        });
-        this.toDeviceTransport.on(KeyTransportEvents.ReceivedKeys, (...props) => {
-            if (this._enabled.toDevice) {
-                this.emit(KeyTransportEvents.ReceivedKeys, ...props);
-            } else {
-                this.logger.debug("To Device transport is disabled, ignoring received keys");
-            }
-        });
-    }
-
-    /** Set which transport type should be used to send and receive keys.*/
-    public setEnabled(enabled: { toDevice: boolean; room: boolean }): void {
-        if (this.enabled.toDevice !== enabled.toDevice || this.enabled.room !== enabled.room) {
-            this._enabled = enabled;
-            this.emit(RoomAndToDeviceEvents.EnabledTransportsChanged, enabled);
-        }
-    }
-
-    /** The currently enabled transports that are used to send and receive keys.*/
-    public get enabled(): EnabledTransports {
-        return this._enabled;
-    }
-
-    public start(): void {
-        // always start the underlying transport since we need to enable room transport
-        // when someone else sends us a room key. (we need to listen to roomKeyTransport)
-        this.roomKeyTransport.start();
-        this.toDeviceTransport.start();
-    }
-
-    public stop(): void {
-        // always stop since it is always running
-        this.roomKeyTransport.stop();
-        this.toDeviceTransport.stop();
-    }
-
-    public async sendKey(keyBase64Encoded: string, index: number, members: ParticipantDeviceInfo[]): Promise<void> {
-        this.logger.debug(
-            `Sending key with index ${index} to call members (count=${members.length}) via:` +
-                (this._enabled.room ? "room transport" : "") +
-                (this._enabled.room && this._enabled.toDevice ? "and" : "") +
-                (this._enabled.toDevice ? "to device transport" : ""),
-        );
-        if (this._enabled.room) await this.roomKeyTransport.sendKey(keyBase64Encoded, index, members);
-        if (this._enabled.toDevice) {
-            try {
-                await this.toDeviceTransport.sendKey(keyBase64Encoded, index, members);
-            } catch (error) {
-                if (error instanceof NotSupportedError && !this._enabled.room) {
-                    this.logger.warn(
-                        "To device is not supported enabling room key transport, disabling toDevice transport",
-                    );
-                    this.setEnabled({ toDevice: false, room: true });
-                    await this.sendKey(keyBase64Encoded, index, members);
-                }
-            }
-        }
-    }
-}

src/matrixrtc/focus.ts

@@ -1,25 +0,0 @@
-/*
-Copyright 2023 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.
-*/
-
-/**
- * Information about a MatrixRTC conference focus. The only attribute that
- * the js-sdk (currently) knows about is the type: applications can extend
- * this class for different types of focus.
- */
-export interface Focus {
-    type: string;
-    [key: string]: unknown;
-}

src/matrixrtc/index.ts

@@ -15,8 +15,7 @@ limitations under the License.
 */
 
 export * from "./CallMembership.ts";
-export type * from "./focus.ts";
-export * from "./LivekitFocus.ts";
+export * from "./LivekitTransport.ts";
 export * from "./MatrixRTCSession.ts";
 export * from "./MatrixRTCSessionManager.ts";
 export type * from "./types.ts";

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";
 
@@ -96,10 +96,56 @@ export interface ICallNotifyContent {
 }
 
 export type RTCNotificationType = "ring" | "notification";
+
+/**
+ * Represents the intention of the call from the perspective of the sending user.
+ * 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;
-    "decline_reason"?: string;
+    "m.mentions"?: IMentions;
     "notification_type": RTCNotificationType;
+    /**
+     * The initial intent of the calling user.
+     */
+    "m.call.intent"?: RTCCallIntent;
     "sender_ts": number;
     "lifetime": number;
 }
@@ -146,3 +192,11 @@ export type Statistics = {
 
 export const isMyMembership = (m: CallMembership, userId: string, deviceId: string): boolean =>
     m.sender === userId && m.deviceId === deviceId;
+
+/**
+ *  A RTC transport is a JSON object that describes how to connect to a RTC member.
+ */
+export interface Transport {
+    type: string;
+    [key: string]: unknown;
+}

src/models/MSC3089TreeSpace.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import promiseRetry from "p-retry";
-
 import { type MatrixClient } from "../client.ts";
 import { EventType, MsgType, UNSTABLE_MSC3089_BRANCH, UNSTABLE_MSC3089_LEAF } from "../@types/event.ts";
 import { type Room } from "./room.ts";
@@ -31,7 +29,7 @@ import {
 } from "../utils.ts";
 import { MSC3089Branch } from "./MSC3089Branch.ts";
 import { type ISendEventResponse } from "../@types/requests.ts";
-import { type FileType } from "../http-api/index.ts";
+import { type FileType, MatrixError } from "../http-api/index.ts";
 import { KnownMembership } from "../@types/membership.ts";
 import { type RoomPowerLevelsEventContent, type SpaceChildEventContent } from "../@types/state_events.ts";
 import type { EncryptedFile, FileContent } from "../@types/media.ts";
@@ -146,16 +144,17 @@ export class MSC3089TreeSpace {
         await Promise.all(promises);
     }
 
-    private retryInvite(userId: string): Promise<void> {
-        return simpleRetryOperation(async () => {
-            await this.client.invite(this.roomId, userId).catch((e) => {
+    private async retryInvite(userId: string): Promise<void> {
+        await simpleRetryOperation(
+            () => this.client.invite(this.roomId, userId),
+            (e) => {
                 // We don't want to retry permission errors forever...
-                if (e?.errcode === "M_FORBIDDEN") {
-                    throw new promiseRetry.AbortError(e);
+                if (e instanceof MatrixError && e.errcode === "M_FORBIDDEN") {
+                    return false;
                 }
-                throw e;
-            });
-        });
+                return true;
+            },
+        );
     }
 
     /**

src/models/event.ts

@@ -75,6 +75,7 @@ export interface IUnsigned {
     "transaction_id"?: string;
     "invite_room_state"?: StrippedState[];
     "m.relations"?: Record<RelationType | string, any>; // No common pattern for aggregated relations
+    "msc4354_sticky_duration_ttl_ms"?: number;
     [UNSIGNED_THREAD_ID_FIELD.name]?: string;
 }
 
@@ -96,6 +97,7 @@ export interface IEvent {
     membership?: Membership;
     unsigned: IUnsigned;
     redacts?: string;
+    msc4354_sticky?: { duration_ms: number };
 }
 
 export interface IAggregatedRelation {
@@ -158,6 +160,7 @@ export interface IMarkedUnreadEvent {
 export interface IClearEvent {
     room_id?: string;
     type: string;
+    state_key?: string;
     content: Omit<IContent, "membership" | "avatar_url" | "displayname" | "m.relates_to">;
     unsigned?: IUnsigned;
 }
@@ -212,6 +215,7 @@ export interface IMessageVisibilityHidden {
 }
 // A singleton implementing `IMessageVisibilityVisible`.
 const MESSAGE_VISIBLE: IMessageVisibilityVisible = Object.freeze({ visible: true });
+export const MAX_STICKY_DURATION_MS = 3600000;
 
 export enum MatrixEventEvent {
     /**
@@ -407,6 +411,17 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
 
     private readonly reEmitter: TypedReEmitter<MatrixEventEmittedEvents, MatrixEventHandlerMap>;
 
+    /**
+     * The timestamp for when this event should expire, in milliseconds.
+     * Prefers using the server-provided value, but will fall back to local calculation.
+     *
+     * This value is **safe** to use, as malicious start time and duration are appropriately capped.
+     *
+     * If the event is not a sticky event (or not supported by the server),
+     * then this returns `undefined`.
+     */
+    public readonly unstableStickyExpiresAt: number | undefined;
+
     /**
      * Construct a Matrix Event object
      *
@@ -446,8 +461,17 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         // The fallback in these cases will be to use the origin_server_ts.
         // For EDUs, the origin_server_ts also is not defined so we use Date.now().
         const age = this.getAge();
-        this.localTimestamp = age !== undefined ? Date.now() - age : (this.getTs() ?? Date.now());
+        const now = Date.now();
+        this.localTimestamp = age !== undefined ? now - age : (this.getTs() ?? now);
         this.reEmitter = new TypedReEmitter(this);
+        if (this.unstableStickyInfo) {
+            if (this.unstableStickyInfo.duration_ttl_ms) {
+                this.unstableStickyExpiresAt = now + this.unstableStickyInfo.duration_ttl_ms;
+            } else {
+                // Bound the timestamp so it doesn't come from the future.
+                this.unstableStickyExpiresAt = Math.min(now, this.getTs()) + this.unstableStickyInfo.duration_ms;
+            }
+        }
     }
 
     /**
@@ -728,11 +752,25 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     }
 
     /**
-     * Get the event state_key if it has one. This will return <code>undefined
-     * </code> for message events.
+     * Get the event state_key if it has one. If necessary, this will perform
+     * string-unpacking on the state key, as per MSC3414. This will return
+     * <code>undefined</code> for message events.
      * @returns The event's `state_key`.
      */
     public getStateKey(): string | undefined {
+        if (this.clearEvent) {
+            return this.clearEvent.state_key;
+        }
+        return this.event.state_key;
+    }
+
+    /**
+     * Get the raw event state_key if it has one. This may be string-packed as per
+     * MSC3414 if the state event is encrypted. This will return <code>undefined
+     * </code> for message events.
+     * @returns The event's `state_key`.
+     */
+    public getWireStateKey(): string | undefined {
         return this.event.state_key;
     }
 
@@ -785,11 +823,17 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         this.clearEvent = {
             type: this.event.type!,
             content: this.event.content!,
+            state_key: this.event.state_key,
         };
         this.event.type = cryptoType;
         this.event.content = cryptoContent;
         this.senderCurve25519Key = senderCurve25519Key;
         this.claimedEd25519Key = claimedEd25519Key;
+
+        // if this is a state event, pack cleartext type and statekey
+        if (this.isState()) {
+            this.event.state_key = `${this.clearEvent!.type}:${this.clearEvent!.state_key}`;
+        }
     }
 
     /**
@@ -1025,7 +1069,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
      * @returns True if this event is encrypted.
      */
     public isEncrypted(): boolean {
-        return !this.isState() && this.event.type === EventType.RoomMessageEncrypted;
+        return this.event.type === EventType.RoomMessageEncrypted;
     }
 
     /**
@@ -1718,6 +1762,24 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     public setThreadId(threadId?: string): void {
         this.threadId = threadId;
     }
+
+    /**
+     * Unstable getter to try and get the sticky information for the event.
+     * If the event is not a sticky event (or not supported by the server),
+     * then this returns `undefined`.
+     *
+     * `duration_ms` is safely bounded to a hour.
+     */
+    public get unstableStickyInfo(): { duration_ms: number; duration_ttl_ms?: number } | undefined {
+        if (!this.event.msc4354_sticky?.duration_ms) {
+            return undefined;
+        }
+        return {
+            duration_ms: Math.min(MAX_STICKY_DURATION_MS, this.event.msc4354_sticky.duration_ms),
+            // This is assumed to be bounded server-side.
+            duration_ttl_ms: this.event.unsigned?.msc4354_sticky_duration_ttl_ms,
+        };
+    }
 }
 
 /* REDACT_KEEP_KEYS gives the keys we keep when an event is redacted

src/models/profile-keys.ts

@@ -1,8 +1,33 @@
+/*
+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.
+*/
+
+/**
+ * The timezone the user is currently in. The value of this property should
+ * match a timezone provided in https://www.iana.org/time-zones.
+ *
+ * This key was introduced in Matrix v1.16.
+ */
+export const ProfileKeyTimezone = "m.tz";
+
 /**
  * The timezone the user is currently in. The value of this property should
  * match a timezone provided in https://www.iana.org/time-zones.
  *
  * @see https://github.com/matrix-org/matrix-spec-proposals/blob/clokep/profile-tz/proposals/4175-profile-field-time-zone.md
  * @experimental
+ * @deprecated Unstable MSC field - Use `ProfileKeyTimezone`
  */
 export const ProfileKeyMSC4175Timezone = "us.cloke.msc4175.tz";

src/models/room-member.ts

@@ -388,7 +388,7 @@ export class RoomMember extends TypedEventEmitter<RoomMemberEvent, RoomMemberEve
     }
 }
 
-const MXID_PATTERN = /@.+:.+/;
+export const MXID_PATTERN = /@.+:.+/;
 const LTR_RTL_PATTERN = /[\u200E\u200F\u202A-\u202F]/;
 
 function shouldDisambiguate(selfUserId: string, displayName?: string, roomState?: RoomState): boolean {

src/models/room-sticky-events.ts

@@ -0,0 +1,383 @@
+import { logger as loggerInstance } from "../logger.ts";
+import { type MatrixEvent } from "./event.ts";
+import { TypedEventEmitter } from "./typed-event-emitter.ts";
+
+const logger = loggerInstance.getChild("RoomStickyEvents");
+
+export enum RoomStickyEventsEvent {
+    Update = "RoomStickyEvents.Update",
+}
+
+export type StickyMatrixEvent = MatrixEvent & { unstableStickyExpiresAt: number };
+
+export type RoomStickyEventsMap = {
+    /**
+     * Fires when any sticky event changes happen in a room.
+     * @param added Any new sticky events with no predecessor events (matching sender, type, and sticky_key)
+     * @param updated Any sticky events that supersede an existing event (matching sender, type, and sticky_key)
+     * @param removed The events that were removed from the map due to expiry.
+     */
+    [RoomStickyEventsEvent.Update]: (
+        added: StickyMatrixEvent[],
+        updated: { current: StickyMatrixEvent; previous: StickyMatrixEvent }[],
+        removed: StickyMatrixEvent[],
+    ) => 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> {
+    /**
+     * 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.
+     */
+    public *getStickyEvents(): Iterable<StickyMatrixEvent> {
+        yield* this.unkeyedStickyEvents;
+        for (const innerMap of this.stickyEventsMap.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];
+            }
+        }
+    }
+
+    /**
+     * Get an active sticky event that match the given `type`, `sender`, and `stickyKey`
+     * @param type The event `type`.
+     * @param sender The sender of the sticky event.
+     * @param stickyKey The sticky key used by the event.
+     * @returns A matching active sticky event, or undefined.
+     */
+    public getKeyedStickyEvent(sender: string, type: string, stickyKey: string): StickyMatrixEvent | undefined {
+        assertIsUserId(sender);
+        return this.stickyEventsMap.get(type)?.get(RoomStickyEventsStore.stickyMapKey(stickyKey, sender))?.[0];
+    }
+
+    /**
+     * Get active sticky events without a sticky key that match the given `type` and `sender`.
+     * @param type The event `type`.
+     * @param sender The sender of the sticky event.
+     * @returns An array of matching sticky events.
+     */
+    public getUnkeyedStickyEvent(sender: string, type: string): StickyMatrixEvent[] {
+        return [...this.unkeyedStickyEvents].filter((ev) => ev.getType() === type && ev.getSender() === sender);
+    }
+
+    /**
+     * Adds a sticky event into the local sticky event map.
+     *
+     * NOTE: This will not cause `RoomEvent.StickyEvents` to be emitted.
+     *
+     * @throws If the `event` does not contain valid sticky data.
+     * @param event The MatrixEvent that contains sticky data.
+     * @returns An object describing whether the event was added to the map,
+     *          and the previous event it may have replaced.
+     */
+    private addStickyEvent(event: MatrixEvent): { added: true; prevEvent?: StickyMatrixEvent } | { added: false } {
+        const stickyKey = event.getContent().msc4354_sticky_key;
+        if (typeof stickyKey !== "string" && stickyKey !== undefined) {
+            throw new Error(`${event.getId()} is missing msc4354_sticky_key`);
+        }
+
+        // With this we have the guarantee, that all events in stickyEventsMap are correctly formatted
+        if (event.unstableStickyExpiresAt === undefined) {
+            throw new Error(`${event.getId()} is missing msc4354_sticky.duration_ms`);
+        }
+        const sender = event.getSender();
+        const type = event.getType();
+        assertIsUserId(sender);
+        if (event.unstableStickyExpiresAt <= Date.now()) {
+            logger.info("ignored sticky event with older expiration time than current time", stickyKey);
+            return { added: false };
+        }
+
+        // While we fully expect the server to always provide the correct value,
+        // this is just insurance to protect against attacks on our Map.
+        if (!sender.startsWith("@")) {
+            throw new Error("Expected sender to start with @");
+        }
+
+        const stickyEvent = 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 };
+        }
+
+        // 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],
+        };
+    }
+
+    /**
+     * Add a series of sticky events, emitting `RoomEvent.StickyEvents` if any
+     * changes were made.
+     * @param events A set of new sticky events.
+     */
+    public addStickyEvents(events: MatrixEvent[]): void {
+        const added: StickyMatrixEvent[] = [];
+        const updated: { current: StickyMatrixEvent; previous: StickyMatrixEvent }[] = [];
+        for (const event of events) {
+            try {
+                const result = this.addStickyEvent(event);
+                if (result.added) {
+                    if (result.prevEvent) {
+                        // e is validated as a StickyMatrixEvent by virtue of `addStickyEvent` returning added: true.
+                        updated.push({ current: event as StickyMatrixEvent, previous: result.prevEvent });
+                    } else {
+                        added.push(event as StickyMatrixEvent);
+                    }
+                }
+            } catch (ex) {
+                logger.warn("ignored invalid sticky event", ex);
+            }
+        }
+        if (added.length || updated.length) this.emit(RoomStickyEventsEvent.Update, added, updated, []);
+        this.scheduleStickyTimer();
+    }
+
+    /**
+     * Schedule the sticky event expiry timer. The timer will
+     * run immediately if an event has already expired.
+     */
+    private scheduleStickyTimer(): void {
+        if (this.stickyEventTimer) {
+            clearTimeout(this.stickyEventTimer);
+            this.stickyEventTimer = undefined;
+        }
+        if (this.nextStickyEventExpiryTs === Number.MAX_SAFE_INTEGER) {
+            // We have no events due to expire.
+            return;
+        } // otherwise, schedule in the future
+        this.stickyEventTimer = setTimeout(this.cleanExpiredStickyEvents, this.nextStickyEventExpiryTs - Date.now());
+    }
+
+    /**
+     * Clean out any expired sticky events.
+     */
+    private readonly cleanExpiredStickyEvents = (): void => {
+        const now = Date.now();
+        const removedEvents: StickyMatrixEvent[] = [];
+
+        // 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, [currentEvent, ...previousEvents]] of innerEvents) {
+                // we only added items with `sticky` into this map so we can assert non-null here
+                if (now >= currentEvent.unstableStickyExpiresAt) {
+                    logger.debug("Expiring sticky event", currentEvent.getId());
+                    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,
+                        currentEvent.unstableStickyExpiresAt,
+                    );
+                }
+            }
+            // Clean up map after use.
+            if (this.stickyEventsMap.get(eventType)?.size === 0) {
+                this.stickyEventsMap.delete(eventType);
+            }
+        }
+        for (const event of this.unkeyedStickyEvents) {
+            if (now >= event.unstableStickyExpiresAt) {
+                logger.debug("Expiring sticky event", event.getId());
+                this.unkeyedStickyEvents.delete(event);
+                removedEvents.push(event);
+            } else {
+                // If not removing the event, check to see if it's the next lowest expiry.
+                this.nextStickyEventExpiryTs = Math.min(this.nextStickyEventExpiryTs, event.unstableStickyExpiresAt);
+            }
+        }
+        if (removedEvents.length) {
+            this.emit(RoomStickyEventsEvent.Update, [], [], removedEvents);
+        }
+        // Finally, schedule the next run.
+        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.
+     */
+    public clear(): void {
+        this.stickyEventsMap.clear();
+        // Unschedule timer.
+        this.nextStickyEventExpiryTs = Number.MAX_SAFE_INTEGER;
+        this.scheduleStickyTimer();
+    }
+}

src/models/room.ts

@@ -77,6 +77,7 @@ import { compareEventOrdering } from "./compare-event-ordering.ts";
 import { KnownMembership, type Membership } from "../@types/membership.ts";
 import { type Capabilities, type IRoomVersionsCapability, RoomVersionStability } from "../serverCapabilities.ts";
 import { type MSC4186Hero } from "../sliding-sync.ts";
+import { RoomStickyEventsStore, RoomStickyEventsEvent, type RoomStickyEventsMap } from "./room-sticky-events.ts";
 
 // These constants are used as sane defaults when the homeserver doesn't support
 // the m.room_versions capability. In practice, KNOWN_SAFE_ROOM_VERSION should be
@@ -167,6 +168,7 @@ export type RoomEmittedEvents =
     | RoomStateEvent.NewMember
     | RoomStateEvent.Update
     | RoomStateEvent.Marker
+    | RoomStickyEventsEvent.Update
     | ThreadEvent.New
     | ThreadEvent.Update
     | ThreadEvent.NewReply
@@ -320,6 +322,7 @@ export type RoomEventHandlerMap = {
 } & Pick<ThreadHandlerMap, ThreadEvent.Update | ThreadEvent.NewReply | ThreadEvent.Delete> &
     EventTimelineSetHandlerMap &
     Pick<MatrixEventHandlerMap, MatrixEventEvent.BeforeRedaction> &
+    Pick<RoomStickyEventsMap, RoomStickyEventsEvent.Update> &
     Pick<
         RoomStateEventHandlerMap,
         | RoomStateEvent.Events
@@ -446,6 +449,11 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      */
     private roomReceipts = new RoomReceipts(this);
 
+    /**
+     * Stores and tracks sticky events
+     */
+    private stickyEvents = new RoomStickyEventsStore();
+
     /**
      * Construct a new Room.
      *
@@ -492,6 +500,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         // Listen to our own receipt event as a more modular way of processing our own
         // receipts. No need to remove the listener: it's on ourself anyway.
         this.on(RoomEvent.Receipt, this.onReceipt);
+        this.reEmitter.reEmit(this.stickyEvents, [RoomStickyEventsEvent.Update]);
 
         // all our per-room timeline sets. the first one is the unfiltered ones;
         // the subsequent ones are the filtered ones in no particular order.
@@ -2624,6 +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);
             }
@@ -3414,6 +3431,55 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         return this.accountData.get(type);
     }
 
+    /**
+     * Get an iterator of currently active sticky events.
+     */
+    // eslint-disable-next-line
+    public _unstable_getStickyEvents(): ReturnType<RoomStickyEventsStore["getStickyEvents"]> {
+        return this.stickyEvents.getStickyEvents();
+    }
+
+    /**
+     * Get a sticky event that match the given `type`, `sender`, and `stickyKey`
+     * @param type The event `type`.
+     * @param sender The sender of the sticky event.
+     * @param stickyKey The sticky key used by the event.
+     * @returns A matching active sticky event, or undefined.
+     */
+    // eslint-disable-next-line
+    public _unstable_getKeyedStickyEvent(
+        sender: string,
+        type: string,
+        stickyKey: string,
+    ): ReturnType<RoomStickyEventsStore["getKeyedStickyEvent"]> {
+        return this.stickyEvents.getKeyedStickyEvent(sender, type, stickyKey);
+    }
+
+    /**
+     * Get active sticky events without a sticky key that match the given `type` and `sender`.
+     * @param type The event `type`.
+     * @param sender The sender of the sticky event.
+     * @returns An array of matching sticky events.
+     */
+    // eslint-disable-next-line
+    public _unstable_getUnkeyedStickyEvent(
+        sender: string,
+        type: string,
+    ): ReturnType<RoomStickyEventsStore["getUnkeyedStickyEvent"]> {
+        return this.stickyEvents.getUnkeyedStickyEvent(sender, type);
+    }
+
+    /**
+     * Add a series of sticky events, emitting `RoomEvent.StickyEvents` if any
+     * changes were made.
+     * @param events A set of new sticky events.
+     * @internal
+     */
+    // eslint-disable-next-line
+    public _unstable_addStickyEvents(events: MatrixEvent[]): ReturnType<RoomStickyEventsStore["addStickyEvents"]> {
+        return this.stickyEvents.addStickyEvents(events);
+    }
+
     /**
      * Returns whether the syncing user has permission to send a message in the room
      * @returns true if the user should be permitted to send

src/rust-crypto/RoomEncryptor.ts

@@ -27,7 +27,7 @@ import {
 } from "@matrix-org/matrix-sdk-crypto-wasm";
 
 import { EventType } from "../@types/event.ts";
-import { type IContent, type MatrixEvent } from "../models/event.ts";
+import { type MatrixEvent, type IContent } from "../models/event.ts";
 import { type Room } from "../models/room.ts";
 import { type Logger, LogSpan } from "../logger.ts";
 import { type KeyClaimManager } from "./KeyClaimManager.ts";
@@ -314,11 +314,23 @@ export class RoomEncryptor {
 
     private async encryptEventInner(logger: LogSpan, event: MatrixEvent): Promise<void> {
         logger.debug("Encrypting actual message content");
-        const encryptedContent = await this.olmMachine.encryptRoomEvent(
-            new RoomId(this.room.roomId),
-            event.getType(),
-            JSON.stringify(event.getContent()),
-        );
+
+        const room = new RoomId(this.room.roomId);
+        const type = event.getType();
+        const content = JSON.stringify(event.getContent());
+
+        let encryptedContent;
+        if (event.isState()) {
+            encryptedContent = await this.olmMachine.encryptStateEvent(
+                room,
+                type,
+                // Safety: we've already checked above that this is a state event, so the state key must exist.
+                event.getStateKey()!,
+                content,
+            );
+        } else {
+            encryptedContent = await this.olmMachine.encryptRoomEvent(room, type, content);
+        }
 
         event.makeEncrypted(
             EventType.RoomMessageEncrypted,

src/rust-crypto/index.ts

@@ -91,6 +91,11 @@ export async function initRustCrypto(args: {
      * Called with (-1, -1) to mark the end of migration.
      */
     legacyMigrationProgressListener?: (progress: number, total: number) => void;
+
+    /**
+     * Whether to enable support for encrypting state events.
+     */
+    enableEncryptedStateEvents?: boolean;
 }): Promise<RustCrypto> {
     const { logger } = args;
 
@@ -128,6 +133,7 @@ export async function initRustCrypto(args: {
         args.cryptoCallbacks,
         storeHandle,
         args.legacyCryptoStore,
+        args.enableEncryptedStateEvents,
     );
 
     storeHandle.free();
@@ -145,6 +151,7 @@ async function initOlmMachine(
     cryptoCallbacks: CryptoCallbacks,
     storeHandle: StoreHandle,
     legacyCryptoStore?: CryptoStore,
+    enableEncryptedStateEvents?: boolean,
 ): Promise<RustCrypto> {
     logger.debug("Init OlmMachine");
 
@@ -167,7 +174,16 @@ async function initOlmMachine(
     // Disable room key requests, per https://github.com/vector-im/element-web/issues/26524.
     olmMachine.roomKeyRequestsEnabled = false;
 
-    const rustCrypto = new RustCrypto(logger, olmMachine, http, userId, deviceId, secretStorage, cryptoCallbacks);
+    const rustCrypto = new RustCrypto(
+        logger,
+        olmMachine,
+        http,
+        userId,
+        deviceId,
+        secretStorage,
+        cryptoCallbacks,
+        enableEncryptedStateEvents,
+    );
 
     await olmMachine.registerRoomKeyUpdatedCallback((sessions: RustSdkCryptoJs.RoomKeyInfo[]) =>
         rustCrypto.onRoomKeysUpdated(sessions),

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";
@@ -162,6 +163,9 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
 
         /** Crypto callbacks provided by the application */
         private readonly cryptoCallbacks: CryptoCallbacks,
+
+        /** Enable support for encrypted state events under MSC3414. */
+        private readonly enableEncryptedStateEvents: boolean = false,
     ) {
         super();
         this.outgoingRequestProcessor = new OutgoingRequestProcessor(logger, olmMachine, http);
@@ -421,6 +425,16 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         return Boolean(roomSettings?.algorithm);
     }
 
+    /**
+     * Implementation of {@link CryptoApi#isStateEncryptionEnabledInRoom}.
+     */
+    public async isStateEncryptionEnabledInRoom(roomId: string): Promise<boolean> {
+        const roomSettings: RustSdkCryptoJs.RoomSettings | undefined = await this.olmMachine.getRoomSettings(
+            new RustSdkCryptoJs.RoomId(roomId),
+        );
+        return Boolean(roomSettings?.encryptStateEvents);
+    }
+
     /**
      * Implementation of {@link CryptoApi#getOwnDeviceKeys}.
      */
@@ -814,6 +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",
@@ -821,13 +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;
     }
 
     /**
@@ -1040,7 +1080,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             new RustSdkCryptoJs.UserId(userId),
         );
         return requests
-            .filter((request) => request.roomId === undefined)
+            .filter((request) => request.roomId === undefined && !request.isCancelled())
             .map((request) => this.makeVerificationRequest(request));
     }
 
@@ -1063,7 +1103,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         );
 
         // Search for the verification request for the given room id
-        const request = requests.find((request) => request.roomId?.toString() === roomId);
+        const request = requests.find((request) => request.roomId?.toString() === roomId && !request.isCancelled());
 
         if (request) {
             return this.makeVerificationRequest(request);
@@ -1717,7 +1757,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         await this.receiveSyncChanges({ devices });
     }
 
-    /** called by the sync loop on m.room.encrypted events
+    /** called by the sync loop on m.room.encryption events
      *
      * @param room - in which the event was received
      * @param event - encryption event to be processed
@@ -1734,6 +1774,11 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             return;
         }
 
+        if (config["io.element.msc3414.encrypt_state_events"] && this.enableEncryptedStateEvents) {
+            this.logger.info("crypto Enabling state event encryption...");
+            settings.encryptStateEvents = true;
+        }
+
         try {
             settings.sessionRotationPeriodMs = config.rotation_period_ms;
             settings.sessionRotationPeriodMessages = config.rotation_period_msgs;
@@ -2035,20 +2080,38 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      */
     private async onKeyVerificationEvent(event: MatrixEvent): Promise<void> {
         const roomId = event.getRoomId();
+        const senderId = event.getSender();
 
         if (!roomId) {
             throw new Error("missing roomId in the event");
         }
 
+        if (!senderId) {
+            throw new Error("missing sender in the event");
+        }
+
         this.logger.debug(
             `Incoming verification event ${event.getId()} type ${event.getType()} from ${event.getSender()}`,
         );
 
-        await this.olmMachine.receiveVerificationEvent(
+        const isRoomVerificationRequest =
+            event.getType() === EventType.RoomMessage && event.getContent().msgtype === MsgType.KeyVerificationRequest;
+
+        if (isRoomVerificationRequest) {
+            // Before processing an in-room verification request, we need to
+            // make sure we have the sender's device information - otherwise we
+            // will immediately abort verification. So we explicitly fetch it
+            // from /keys/query and wait for that request to complete before we
+            // call receiveVerificationEvent.
+            const req = this.getOlmMachineOrThrow().queryKeysForUsers([new RustSdkCryptoJs.UserId(senderId)]);
+            await this.outgoingRequestProcessor.makeOutgoingRequest(req);
+        }
+
+        await this.getOlmMachineOrThrow().receiveVerificationEvent(
             JSON.stringify({
                 event_id: event.getId(),
                 type: event.getType(),
-                sender: event.getSender(),
+                sender: senderId,
                 state_key: event.getStateKey(),
                 content: event.getContent(),
                 origin_server_ts: event.getTs(),
@@ -2056,11 +2119,8 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             new RustSdkCryptoJs.RoomId(roomId),
         );
 
-        if (
-            event.getType() === EventType.RoomMessage &&
-            event.getContent().msgtype === MsgType.KeyVerificationRequest
-        ) {
-            this.onIncomingKeyVerificationRequest(event.getSender()!, event.getId()!);
+        if (isRoomVerificationRequest) {
+            this.onIncomingKeyVerificationRequest(senderId, event.getId()!);
         }
 
         // that may have caused us to queue up outgoing requests, so make sure we send them.

src/serverCapabilities.ts

@@ -64,6 +64,10 @@ export interface Capabilities {
     "m.set_displayname"?: ISetDisplayNameCapability;
     "m.set_avatar_url"?: ISetAvatarUrlCapability;
     "uk.tcpip.msc4133.profile_fields"?: IProfileFieldsCapability;
+    /**
+     * Since Matrix v1.16
+     */
+    "m.profile_fields"?: IProfileFieldsCapability;
 }
 
 type CapabilitiesResponse = {

src/sync-accumulator.ts

@@ -20,7 +20,7 @@ limitations under the License.
 
 import { logger } from "./logger.ts";
 import { deepCopy } from "./utils.ts";
-import { type IContent, type IUnsigned } from "./models/event.ts";
+import { MAX_STICKY_DURATION_MS, type IContent, type IUnsigned } from "./models/event.ts";
 import { type IRoomSummary } from "./models/room-summary.ts";
 import { type EventType } from "./@types/event.ts";
 import { UNREAD_THREAD_NOTIFICATIONS } from "./@types/sync.ts";
@@ -76,11 +76,25 @@ export interface ITimeline {
     prev_batch: string | null;
 }
 
+type StickyEventFields = {
+    msc4354_sticky: { duration_ms: number };
+    content: { msc4354_sticky_key?: string };
+};
+
+export type IStickyEvent = IRoomEvent & StickyEventFields;
+
+export type IStickyStateEvent = IStateEvent & StickyEventFields;
+
+export interface ISticky {
+    events: Array<IStickyEvent | IStickyStateEvent>;
+}
+
 export interface IJoinedRoom {
     "summary": IRoomSummary;
     // One of `state` or `state_after` is required.
     "state"?: IState;
     "org.matrix.msc4222.state_after"?: IState; // https://github.com/matrix-org/matrix-spec-proposals/pull/4222
+    "msc4354_sticky"?: ISticky; // https://github.com/matrix-org/matrix-spec-proposals/pull/4354
     "timeline": ITimeline;
     "ephemeral": IEphemeral;
     "account_data": IAccountData;
@@ -201,6 +215,14 @@ interface IRoom {
     _unreadNotifications: Partial<UnreadNotificationCounts>;
     _unreadThreadNotifications?: Record<string, Partial<UnreadNotificationCounts>>;
     _receipts: ReceiptAccumulator;
+    _stickyEvents: {
+        readonly event: IStickyEvent | IStickyStateEvent;
+        /**
+         * This is the timestamp at which point it is safe to remove this event from the store.
+         * This value is immutable
+         */
+        readonly expiresTs: number;
+    }[];
 }
 
 export interface ISyncData {
@@ -411,6 +433,7 @@ export class SyncAccumulator {
 
     // Accumulate timeline and state events in a room.
     private accumulateJoinState(roomId: string, data: IJoinedRoom, fromDatabase = false): void {
+        const now = Date.now();
         // We expect this function to be called a lot (every /sync) so we want
         // this to be fast. /sync stores events in an array but we often want
         // to clobber based on type/state_key. Rather than convert arrays to
@@ -457,6 +480,7 @@ export class SyncAccumulator {
                 _unreadThreadNotifications: {},
                 _summary: {},
                 _receipts: new ReceiptAccumulator(),
+                _stickyEvents: [],
             };
         }
         const currentData = this.joinRooms[roomId];
@@ -540,6 +564,27 @@ export class SyncAccumulator {
             });
         });
 
+        // Prune out any events in our stores that have since expired, do this before we
+        // insert new events.
+        currentData._stickyEvents = currentData._stickyEvents.filter(({ expiresTs }) => expiresTs > now);
+
+        // We want this to be fast, so don't worry about duplicate events here. The RoomStickyEventsStore will
+        // process these events into the correct mapped order.
+        if (data.msc4354_sticky?.events) {
+            currentData._stickyEvents = currentData._stickyEvents.concat(
+                data.msc4354_sticky.events.map((event) => {
+                    // If `duration_ms` exceeds the spec limit of a hour, we cap it.
+                    const cappedDuration = Math.min(event.msc4354_sticky.duration_ms, MAX_STICKY_DURATION_MS);
+                    // If `origin_server_ts` claims to have been from the future, we still bound it to now.
+                    const createdTs = Math.min(event.origin_server_ts, now);
+                    return {
+                        event,
+                        expiresTs: cappedDuration + createdTs,
+                    };
+                }),
+            );
+        }
+
         // attempt to prune the timeline by jumping between events which have
         // pagination tokens.
         if (currentData._timeline.length > this.opts.maxTimelineEntries!) {
@@ -611,6 +656,11 @@ export class SyncAccumulator {
                 "unread_notifications": roomData._unreadNotifications,
                 "unread_thread_notifications": roomData._unreadThreadNotifications,
                 "summary": roomData._summary as IRoomSummary,
+                "msc4354_sticky": roomData._stickyEvents?.length
+                    ? {
+                          events: roomData._stickyEvents.map((e) => e.event),
+                      }
+                    : undefined,
             };
             // Add account data
             Object.keys(roomData._accountData).forEach((evType) => {

src/sync.ts

@@ -1082,6 +1082,8 @@ export class SyncApi {
         //              highlight_count: 0,
         //              notification_count: 0,
         //          }
+        //          "org.matrix.msc4222.state_after": { events: [] },  // only if "org.matrix.msc4222.use_state_after" is true
+        //          msc4354_sticky: { events: [] }, // only if "org.matrix.msc4354.sticky" is true
         //        }
         //      },
         //      leave: {
@@ -1219,6 +1221,7 @@ export class SyncApi {
             const timelineEvents = this.mapSyncEventsFormat(joinObj.timeline, room, false);
             const ephemeralEvents = this.mapSyncEventsFormat(joinObj.ephemeral);
             const accountDataEvents = this.mapSyncEventsFormat(joinObj.account_data);
+            const stickyEvents = this.mapSyncEventsFormat(joinObj.msc4354_sticky);
 
             // If state_after is present, this is the events that form the state at the end of the timeline block and
             // regular timeline events do *not* count towards state. If it's not present, then the state is formed by
@@ -1366,6 +1369,13 @@ export class SyncApi {
                 }
             }
 
+            // Proactively decrypt state events: normally we decrypt on demand, but for state
+            // events we need them immediately, so we handle them here. Specifically, consumers
+            // (e.g. Element Web) expect state events to be unencrypted upon receipt.
+            for (const ev of timelineEvents.filter((ev) => ev.isState())) {
+                await this.client.decryptEventIfNeeded(ev);
+            }
+
             try {
                 if ("org.matrix.msc4222.state_after" in joinObj) {
                     await this.injectRoomEvents(
@@ -1395,6 +1405,18 @@ export class SyncApi {
             // we deliberately don't add accountData to the timeline
             room.addAccountData(accountDataEvents);
 
+            // Sticky events primarily come via the `timeline` field, with the
+            // sticky info field marking them as sticky.
+            // If the sync is "gappy" (meaning it is skipping events to catch up) then
+            // sticky events will instead come down the sticky section.
+            // This ensures we collect sticky events from both places.
+            const stickyEventsAndStickyEventsFromTheTimeline = stickyEvents.concat(
+                timelineEvents.filter((e) => e.unstableStickyInfo !== undefined),
+            );
+            // Note: We calculate sticky events before emitting `.Room` as it's nice to have
+            // sticky events calculated and ready to go.
+            room._unstable_addStickyEvents(stickyEventsAndStickyEventsFromTheTimeline);
+
             room.recalculate();
             if (joinObj.isBrandNewRoom) {
                 client.store.storeRoom(room);
@@ -1404,11 +1426,21 @@ export class SyncApi {
             this.processEventsForNotifs(room, timelineEvents);
 
             const emitEvent = (e: MatrixEvent): boolean => client.emit(ClientEvent.Event, e);
+            // this fires a couple of times for some events. (eg state events are in the timeline and the state)
+            // should this get a sync section as an additional event emission param (e, syncSection))?
             stateEvents.forEach(emitEvent);
             timelineEvents.forEach(emitEvent);
             ephemeralEvents.forEach(emitEvent);
             accountDataEvents.forEach(emitEvent);
-
+            stickyEvents
+                .filter(
+                    (stickyEvent) =>
+                        // This is highly unlikey, but in the case where a sticky event
+                        // has appeared in the timeline AND the sticky section, we only
+                        // want to emit the event once.
+                        !timelineEvents.some((timelineEvent) => timelineEvent.getId() === stickyEvent.getId()),
+                )
+                .forEach(emitEvent);
             // Decrypt only the last message in all rooms to make sure we can generate a preview
             // And decrypt all events after the recorded read receipt to ensure an accurate
             // notification count

src/utils.ts

@@ -465,15 +465,21 @@ export async function chunkPromises<T>(fns: (() => Promise<T>)[], chunkSize: num
  * should always return a new promise.
  * @param promiseFn - The function to call to get a fresh promise instance. Takes an
  * attempt count as an argument, for logging/debugging purposes.
+ * @param shouldRetry - Optional function which is called with the error the latest rejection from promiseFn,
+ * retrying will ba aborted if this return false.
  * @returns The promise for the retried operation.
  */
-export function simpleRetryOperation<T>(promiseFn: (attempt: number) => Promise<T>): Promise<T> {
+export function simpleRetryOperation<T>(
+    promiseFn: (attempt: number) => Promise<T>,
+    shouldRetry?: (e: unknown) => boolean,
+): Promise<T> {
     return promiseRetry(
         (attempt: number) => {
             return promiseFn(attempt);
         },
         {
-            forever: true,
+            retries: Infinity,
+            shouldRetry: shouldRetry ? ({ error }): boolean => shouldRetry(error) : undefined,
             factor: 2,
             minTimeout: 3000, // ms
             maxTimeout: 15000, // ms