v39.4.0

* Update encrypted state to say MSC4362 everywhere

* Fix test failure with encrypted state: handle empty string state key

.github/labels.yml

@@ -41,3 +41,6 @@
 - name: "Z-Flaky-Test"
   description: "A test is raising false alarms"
   color: "ededed"
+- name: "Z-Skip-Coverage"
+  description: "Skip SonarQube coverage for this PR"
+  color: "ededed"

.github/workflows/docs-pr-netlify.yaml

@@ -15,7 +15,7 @@ jobs:
             deployments: write
         steps:
             - name: 📥 Download artifact
-              uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5
+              uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6
               with:
                   github-token: ${{ secrets.GITHUB_TOKEN }}
                   run-id: ${{ github.event.workflow_run.id }}

.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

@@ -73,6 +73,8 @@ jobs:
     close-if-fork-develop:
         name: Forbid develop branch fork contributions
         runs-on: ubuntu-24.04
+        permissions:
+            pull-requests: write
         if: >
             github.event.action == 'opened' &&
             github.event.pull_request.head.ref == 'develop' &&

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

@@ -16,12 +16,12 @@ jobs:
             contents: write
         steps:
             - name: 🧮 Checkout code
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   ref: staging
                   fetch-depth: 0
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   node-version-file: package.json
                   cache: "yarn"
@@ -37,7 +37,7 @@ jobs:
                   disable-autolabeler: true
 
             - name: Get actions scripts
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: matrix-org/matrix-js-sdk
                   persist-credentials: false

.github/workflows/release-gitflow.yml

@@ -18,14 +18,14 @@ jobs:
     merge:
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   # We will be pushing to this branch and want the CI to run after we do so we cannot use the GITHUB_TOKEN
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                   fetch-depth: 0
 
             - name: Get actions scripts
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: matrix-org/matrix-js-sdk
                   persist-credentials: false
@@ -33,7 +33,7 @@ jobs:
                   sparse-checkout: |
                       scripts/release
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/release-make.yml

@@ -4,8 +4,6 @@ on:
         secrets:
             ELEMENT_BOT_TOKEN:
                 required: true
-            NPM_TOKEN:
-                required: false
             GPG_PASSPHRASE:
                 required: false
             GPG_PRIVATE_KEY:
@@ -73,7 +71,7 @@ jobs:
                   draft: true
                   latest: true
 
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   ref: staging
                   # We will be pushing to this branch and want the CI to run after we do so we cannot use the GITHUB_TOKEN
@@ -81,7 +79,7 @@ jobs:
                   fetch-depth: 0
 
             - name: Get actions scripts
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: matrix-org/matrix-js-sdk
                   persist-credentials: false
@@ -125,7 +123,7 @@ jobs:
                   git config --global user.email "releases@riot.im"
                   git config --global user.name "RiotRobot"
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -282,8 +280,6 @@ jobs:
         permissions:
             contents: read
             id-token: write
-        secrets:
-            NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
 
     post-release:
         name: Post release steps

.github/workflows/release-npm.yml

@@ -1,9 +1,6 @@
 name: Publish to npm
 on:
     workflow_call:
-        secrets:
-            NPM_TOKEN:
-                required: true
         outputs:
             id:
                 description: "The npm package@version string we published"
@@ -20,32 +17,29 @@ jobs:
             id: ${{ steps.npm-publish.outputs.id }}
         steps:
             - name: 🧮 Checkout code
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   ref: staging
 
             - name: 🔧 Yarn cache
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   registry-url: "https://registry.npmjs.org"
                   node-version-file: package.json
 
+            # Ensure npm 11.5.1 or later is installed
+            - name: Update npm
+              run: npm install -g npm@latest
+
             - name: 🔨 Install dependencies
               run: "yarn install --frozen-lockfile"
 
             - name: 🚀 Publish to npm
               id: npm-publish
               run: |
-                  npm publish --provenance --access public --tag next
+                  npm publish --provenance --access public --tag "$TAG"
                   release=$(jq -r '"\(.name)@\(.version)"' package.json)
                   echo "id=$release" >> $GITHUB_OUTPUT
               env:
-                  NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-
-            - name: 🎖️ Add `latest` dist-tag to final releases
-              if: steps.npm-publish.outputs.id && !contains(steps.npm-publish.outputs.id, '-rc.')
-              run: npm dist-tag add "$release" latest
-              env:
-                  NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}
-                  release: ${{ steps.npm-publish.outputs.id }}
+                  TAG: ${{ contains(steps.npm-publish.outputs.id, '-rc.') && 'next' || 'latest' }}

.github/workflows/release.yml

@@ -44,13 +44,13 @@ jobs:
                 repo:
                     - element-hq/element-web
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: ${{ matrix.repo }}
                   ref: staging
                   token: ${{ secrets.ELEMENT_BOT_TOKEN }}
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: "lts/*"
@@ -73,10 +73,10 @@ jobs:
         runs-on: ubuntu-24.04
         steps:
             - name: 🧮 Checkout code
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
             - name: 🔧 Yarn cache
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json

.github/workflows/sonarcloud.yml

@@ -36,14 +36,14 @@ jobs:
                   target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
 
             - name: "🧮 Checkout code"
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: ${{ github.event.workflow_run.head_repository.full_name }}
                   ref: ${{ github.event.workflow_run.head_branch }} # checkout commit that triggered this workflow
                   fetch-depth: 0 # Shallow clones should be disabled for a better relevancy of analysis
 
             - name: 📥 Download artifact
-              uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5
+              uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6
               if: ${{ !inputs.sharded }}
               with:
                   github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -51,7 +51,7 @@ jobs:
                   name: coverage
                   path: coverage
             - name: 📥 Download sharded artifacts
-              uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5
+              uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6
               if: inputs.sharded
               with:
                   github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -75,13 +75,14 @@ jobs:
 
             - name: "🩻 SonarCloud Scan"
               id: sonarcloud
-              uses: matrix-org/sonarcloud-workflow-action@820f7c2e9e94ba9e35add0f739691e5c7e23fa25 # v4.0
+              uses: matrix-org/sonarcloud-workflow-action@035ca8a2a741dd940f2e6c16d7d078312d625ac6 # v4.0
               # workflow_run fails report against the develop commit always, we don't want that for PRs
               continue-on-error: ${{ github.event.workflow_run.head_branch != 'develop' }}
               with:
                   skip_checkout: true
                   repository: ${{ github.event.workflow_run.head_repository.full_name }}
                   is_pr: ${{ github.event.workflow_run.event == 'pull_request' }}
+                  skip_coverage_label: Z-Skip-Coverage
                   version_cmd: "cat package.json | jq -r .version"
                   branch: ${{ github.event.workflow_run.head_branch }}
                   revision: ${{ github.event.workflow_run.head_sha }}

.github/workflows/static_analysis.yml

@@ -14,9 +14,9 @@ jobs:
         name: "Typescript Syntax Check"
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -31,9 +31,9 @@ jobs:
         name: "ESLint"
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -48,9 +48,9 @@ jobs:
         name: "Node.js example"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -61,7 +61,7 @@ jobs:
             - name: Build Types
               run: "yarn build:types"
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "npm"
                   node-version-file: "examples/node/package.json"
@@ -83,9 +83,9 @@ jobs:
         name: "Workflow Lint"
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -100,9 +100,9 @@ jobs:
         name: "JSDoc Checker"
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -114,7 +114,7 @@ jobs:
               run: "yarn run gendoc --treatWarningsAsErrors --suppressCommentWarningsInDeclarationFiles"
 
             - name: Upload Artifact
-              uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+              uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5
               with:
                   name: docs
                   path: _docs
@@ -125,9 +125,9 @@ jobs:
         name: "Analyse Dead Code"
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version-file: package.json
@@ -143,11 +143,11 @@ jobs:
         if: github.event_name == 'merge_group'
         runs-on: ubuntu-24.04
         steps:
-            - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+            - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
               with:
                   repository: element-hq/element-web
 
-            - uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+            - uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: "lts/*"

.github/workflows/tests.yml

@@ -22,11 +22,11 @@ jobs:
                 node: ["lts/*", 22]
         steps:
             - name: Checkout code
-              uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5
+              uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6
 
             - name: Setup Node
               id: setupNode
-              uses: actions/setup-node@a0853c24544627f65ddf259abe73b1d18a591444 # v5
+              uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6
               with:
                   cache: "yarn"
                   node-version: ${{ matrix.node }}
@@ -57,7 +57,7 @@ jobs:
 
             - name: Upload Artifact
               if: env.ENABLE_COVERAGE == 'true'
-              uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+              uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5
               with:
                   name: coverage-${{ matrix.specs }}-${{ matrix.node == 'lts/*' && 'lts' || matrix.node }}
                   path: |

.github/workflows/triage-stale.yml

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

CHANGELOG.md

@@ -1,3 +1,55 @@
+Changes in [39.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.4.0) (2025-12-16)
+==================================================================================================
+## ✨ Features
+
+* Import room key bundles received after invite. ([#5080](https://github.com/matrix-org/matrix-js-sdk/pull/5080)). Contributed by @kaylendog.
+
+## 🐛 Bug Fixes
+
+* Allow msc4354\_sticky\_key to be optional on sticky events. ([#5073](https://github.com/matrix-org/matrix-js-sdk/pull/5073)). Contributed by @Half-Shot.
+* Handle all response fields from /context API being optional ([#5089](https://github.com/matrix-org/matrix-js-sdk/pull/5089)). Contributed by @t3chguy.
+
+
+Changes in [39.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.3.0) (2025-12-02)
+==================================================================================================
+## 🐛 Bug Fixes
+
+* Re-add truthy check on room name/avatar/alias events ([#5081](https://github.com/matrix-org/matrix-js-sdk/pull/5081)). Contributed by @t3chguy.
+* Fix invalid state events corrupting room objects ([#5078](https://github.com/matrix-org/matrix-js-sdk/pull/5078)). Contributed by @t3chguy.
+
+
+Changes in [39.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.2.0) (2025-11-18)
+==================================================================================================
+## ✨ Features
+
+* Delayed event management: split endpoints, no auth ([#5066](https://github.com/matrix-org/matrix-js-sdk/pull/5066)). Contributed by @AndrewFerr.
+* do not set cache in authenticated fetch ([#5020](https://github.com/matrix-org/matrix-js-sdk/pull/5020)). Contributed by @pkuzco.
+
+## 🐛 Bug Fixes
+
+* Fix media switching during legacy calls ([#5069](https://github.com/matrix-org/matrix-js-sdk/pull/5069)). Contributed by @langleyd.
+
+
+Changes in [39.1.2](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v39.1.2) (2025-11-04)
+==================================================================================================
+Re-release of v39.1.0 to fix npm publishing workflow
+
+
+
+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

code_style.md

@@ -71,7 +71,7 @@ Unless otherwise specified, the following applies to all code:
 11. If a variable is not receiving a value on declaration, its type must be defined.
 
     ```typescript
-    let errorMessage: Optional<string>;
+    let errorMessage: string;
     ```
 
 12. Objects can use shorthand declarations, including mixing of types.
@@ -150,8 +150,7 @@ Unless otherwise specified, the following applies to all code:
     1. When using `any`, a comment explaining why must be present.
 27. `import` should be used instead of `require`, as `require` does not have types.
 28. Export only what can be reused.
-29. Prefer a type like `Optional<X>` (`type Optional<T> = T | null | undefined`) instead
-    of truly optional parameters.
+29. Prefer a type like `X | null` instead of truly optional parameters.
     1. A notable exception is when the likelihood of a bug is minimal, such as when a function
        takes an argument that is more often not required than required. An example where the
        `?` operator is inappropriate is when taking a room ID: typically the caller should
@@ -161,7 +160,7 @@ Unless otherwise specified, the following applies to all code:
         ```typescript
         function doThingWithRoom(
             thing: string,
-            room: Optional<string>, // require the caller to specify
+            room: string | null, // require the caller to specify
         ) {
             // ...
         }

knip.ts

@@ -34,6 +34,8 @@ export default {
         "ts-node",
         // Used by `@babel/plugin-transform-runtime`
         "@babel/runtime",
+        // Transitive dep of jest
+        "jsdom",
     ],
     ignoreBinaries: [
         // Used when available by reusable workflow `.github/workflows/release-make.yml`

package.json

@@ -1,6 +1,6 @@
 {
     "name": "matrix-js-sdk",
-    "version": "39.0.0",
+    "version": "39.4.0",
     "description": "Matrix Client-Server SDK for Javascript",
     "engines": {
         "node": ">=22.0.0"
@@ -56,10 +56,10 @@
         "jwt-decode": "^4.0.0",
         "loglevel": "^1.9.2",
         "matrix-events-sdk": "0.0.1",
-        "matrix-widget-api": "^1.10.0",
+        "matrix-widget-api": "^1.14.0",
         "oidc-client-ts": "^3.0.1",
         "p-retry": "7",
-        "sdp-transform": "^2.14.1",
+        "sdp-transform": "^3.0.0",
         "unhomoglyph": "^1.0.6",
         "uuid": "13"
     },
@@ -84,12 +84,12 @@
         "@stylistic/eslint-plugin": "^5.0.0",
         "@types/content-type": "^1.1.5",
         "@types/debug": "^4.1.7",
-        "@types/jest": "^29.0.0",
+        "@types/jest": "^30.0.0",
         "@types/node": "18",
         "@types/sdp-transform": "^2.4.5",
         "@typescript-eslint/eslint-plugin": "^8.0.0",
         "@typescript-eslint/parser": "^8.0.0",
-        "babel-jest": "^29.0.0",
+        "babel-jest": "^30.0.0",
         "babel-plugin-search-and-replace": "^1.1.1",
         "debug": "^4.3.4",
         "eslint": "8.57.1",
@@ -97,20 +97,20 @@
         "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-tsdoc": "^0.5.0",
         "eslint-plugin-unicorn": "^56.0.0",
         "fake-indexeddb": "^5.0.2",
         "fetch-mock": "11.1.5",
         "fetch-mock-jest": "^1.5.1",
         "husky": "^9.0.0",
-        "jest": "^29.0.0",
-        "jest-environment-jsdom": "^29.0.0",
+        "jest": "^30.0.0",
+        "jest-environment-jsdom": "^30.0.0",
         "jest-localstorage-mock": "^2.4.6",
-        "jest-mock": "^29.0.0",
+        "jest-mock": "^30.0.0",
         "knip": "^5.0.0",
         "lint-staged": "^16.0.0",
         "matrix-mock-request": "^2.5.0",

spec/integ/crypto/history-sharing.spec.ts

@@ -30,7 +30,7 @@ import {
 import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver.ts";
 import { SyncResponder } from "../../test-utils/SyncResponder.ts";
 import { mockInitialApiRequests, mockSetupCrossSigningRequests } from "../../test-utils/mockEndpoints.ts";
-import { getSyncResponse, mkEventCustom, syncPromise } from "../../test-utils/test-utils.ts";
+import { getSyncResponse, mkEventCustom, syncPromise, waitFor } from "../../test-utils/test-utils.ts";
 import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder.ts";
 import { flushPromises } from "../../test-utils/flushPromises.ts";
 import { E2EOTKClaimResponder } from "../../test-utils/E2EOTKClaimResponder.ts";
@@ -80,6 +80,9 @@ describe("History Sharing", () => {
     let bobSyncResponder: SyncResponder;
 
     beforeEach(async () => {
+        // Reset mocks.
+        fetchMock.reset();
+
         // anything that we don't have a specific matcher for silently returns a 404
         fetchMock.catch(404);
         fetchMock.config.warnOnFallback = false;
@@ -201,6 +204,104 @@ describe("History Sharing", () => {
         expect(event.getContent().body).toEqual("Hi!");
     });
 
+    test("Room keys are imported correctly if invite is accepted before the bundle arrives", async () => {
+        // Alice is in an encrypted room
+        const syncResponse = getSyncResponse([aliceClient.getSafeUserId()], ROOM_ID);
+        aliceSyncResponder.sendOrQueueSyncResponse(syncResponse);
+        await syncPromise(aliceClient);
+
+        // ... and she sends an event
+        const msgProm = expectSendRoomEvent(ALICE_HOMESERVER_URL, "m.room.encrypted");
+        await aliceClient.sendEvent(ROOM_ID, EventType.RoomMessage, { msgtype: MsgType.Text, body: "Hello!" });
+        const sentMessage = await msgProm;
+        debug(`Alice sent encrypted room event: ${JSON.stringify(sentMessage)}`);
+
+        // Now, Alice invites Bob
+        const uploadProm = new Promise<Uint8Array>((resolve) => {
+            fetchMock.postOnce(new URL("/_matrix/media/v3/upload", ALICE_HOMESERVER_URL).toString(), (url, request) => {
+                const body = request.body as Uint8Array;
+                debug(`Alice uploaded blob of length ${body.length}`);
+                resolve(body);
+                return { content_uri: "mxc://alice-server/here" };
+            });
+        });
+        const toDeviceMessageProm = expectSendToDeviceMessage(ALICE_HOMESERVER_URL, "m.room.encrypted");
+        // POST https://alice-server.com/_matrix/client/v3/rooms/!room%3Aexample.com/invite
+        fetchMock.postOnce(`${ALICE_HOMESERVER_URL}/_matrix/client/v3/rooms/${encodeURIComponent(ROOM_ID)}/invite`, {});
+        await aliceClient.invite(ROOM_ID, bobClient.getSafeUserId(), { shareEncryptedHistory: true });
+        const uploadedBlob = await uploadProm;
+        const sentToDeviceRequest = await toDeviceMessageProm;
+        debug(`Alice sent encrypted to-device events: ${JSON.stringify(sentToDeviceRequest)}`);
+        const bobToDeviceMessage = sentToDeviceRequest[bobClient.getSafeUserId()][bobClient.deviceId!];
+        expect(bobToDeviceMessage).toBeDefined();
+
+        // Bob receives the room invite, but not the room key bundle
+        const inviteEvent = mkEventCustom({
+            type: "m.room.member",
+            sender: aliceClient.getSafeUserId(),
+            state_key: bobClient.getSafeUserId(),
+            content: { membership: KnownMembership.Invite },
+        });
+        bobSyncResponder.sendOrQueueSyncResponse({
+            rooms: { invite: { [ROOM_ID]: { invite_state: { events: [inviteEvent] } } } },
+        });
+        await syncPromise(bobClient);
+
+        const room = bobClient.getRoom(ROOM_ID);
+        expect(room).toBeTruthy();
+        expect(room?.getMyMembership()).toEqual(KnownMembership.Invite);
+
+        fetchMock.postOnce(`${BOB_HOMESERVER_URL}/_matrix/client/v3/join/${encodeURIComponent(ROOM_ID)}`, {
+            room_id: ROOM_ID,
+        });
+        await bobClient.joinRoom(ROOM_ID, { acceptSharedHistory: true });
+
+        // Bob receives and attempts to decrypt the megolm message, but should not be able to (yet).
+        const bobSyncResponse = getSyncResponse([aliceClient.getSafeUserId(), bobClient.getSafeUserId()], ROOM_ID);
+        bobSyncResponse.rooms.join[ROOM_ID].timeline.events.push(
+            mkEventCustom({
+                type: "m.room.encrypted",
+                sender: aliceClient.getSafeUserId(),
+                content: sentMessage,
+                event_id: "$event_id",
+            }) as any,
+        );
+        bobSyncResponder.sendOrQueueSyncResponse(bobSyncResponse);
+        await syncPromise(bobClient);
+        const bobRoom = bobClient.getRoom(ROOM_ID);
+        const event = bobRoom!.getLastLiveEvent()!;
+        expect(event.getId()).toEqual("$event_id");
+        await event.getDecryptionPromise();
+        expect(event.isDecryptionFailure()).toBeTruthy();
+
+        // Now the room key bundle message arrives
+        fetchMock.getOnce(
+            `begin:${BOB_HOMESERVER_URL}/_matrix/client/v1/media/download/alice-server/here`,
+            { body: uploadedBlob },
+            { sendAsJson: false },
+        );
+        bobSyncResponder.sendOrQueueSyncResponse({
+            to_device: {
+                events: [
+                    {
+                        type: "m.room.encrypted",
+                        sender: aliceClient.getSafeUserId(),
+                        content: bobToDeviceMessage,
+                    },
+                ],
+            },
+        });
+        await syncPromise(bobClient);
+
+        // Once the room key bundle finishes downloading, we should be able to decrypt the message.
+        await waitFor(async () => {
+            await event.getDecryptionPromise();
+            expect(event.isDecryptionFailure()).toBeFalsy();
+            expect(event.getType()).toEqual("m.room.message");
+            expect(event.getContent().body).toEqual("Hello!");
+        });
+    });
+
     afterEach(async () => {
         bobClient.stopClient();
         aliceClient.stopClient();

spec/integ/crypto/olm-utils.ts

@@ -305,7 +305,9 @@ export function encryptMegolmEventRawPlainText(opts: {
         },
         type: "m.room.encrypted",
         unsigned: {},
-        state_key: opts.plaintext.state_key ? `${opts.plaintext.type}:${opts.plaintext.state_key}` : undefined,
+        state_key: opts.plaintext.hasOwnProperty("state_key")
+            ? `${opts.plaintext.type}:${opts.plaintext.state_key}`
+            : undefined,
     };
 }
 

spec/integ/matrix-client-event-timeline.spec.ts

@@ -672,7 +672,7 @@ describe("MatrixClient event timelines", function () {
             expect(timeline!.getEvents().find((e) => e.getId() === THREAD_ROOT.event_id!)).toBeTruthy();
         });
 
-        it("should return undefined when event is not in the thread that the given timelineSet is representing", () => {
+        it("should return null when event is not in the thread that the given timelineSet is representing", () => {
             // @ts-ignore
             client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
@@ -696,12 +696,12 @@ describe("MatrixClient event timelines", function () {
                 });
 
             return Promise.all([
-                expect(client.getEventTimeline(timelineSet, EVENTS[0].event_id!)).resolves.toBeUndefined(),
+                expect(client.getEventTimeline(timelineSet, EVENTS[0].event_id!)).resolves.toBeNull(),
                 httpBackend.flushAllExpected(),
             ]);
         });
 
-        it("should return undefined when event is within a thread but timelineSet is not", () => {
+        it("should return null when event is within a thread but timelineSet is not", () => {
             // @ts-ignore
             client.clientOpts.threadSupport = true;
             Thread.setServerSideSupport(FeatureSupport.Experimental);
@@ -723,7 +723,7 @@ describe("MatrixClient event timelines", function () {
                 });
 
             return Promise.all([
-                expect(client.getEventTimeline(timelineSet, THREAD_REPLY.event_id!)).resolves.toBeUndefined(),
+                expect(client.getEventTimeline(timelineSet, THREAD_REPLY.event_id!)).resolves.toBeNull(),
                 httpBackend.flushAllExpected(),
             ]);
         });

spec/test-utils/test-utils.ts

@@ -82,7 +82,7 @@ export function getSyncResponse(
                     state_key: "",
                     content: {
                         "algorithm": "m.megolm.v1.aes-sha2",
-                        "io.element.msc3414.encrypt_state_events": encryptStateEvents,
+                        "io.element.msc4362.encrypt_state_events": encryptStateEvents,
                     },
                 }),
             ],

spec/unit/embedded.spec.ts

@@ -86,7 +86,9 @@ class MockWidgetApi extends EventEmitter {
                 ? { event_id: `$${Math.random()}` }
                 : { delay_id: `id-${Math.random()}` },
     );
-    public updateDelayedEvent = jest.fn().mockResolvedValue(undefined);
+    public cancelScheduledDelayedEvent = jest.fn().mockResolvedValue(undefined);
+    public restartScheduledDelayedEvent = jest.fn().mockResolvedValue(undefined);
+    public sendScheduledDelayedEvent = jest.fn().mockResolvedValue(undefined);
     public sendToDevice = jest.fn().mockResolvedValue(undefined);
     public requestOpenIDConnectToken = jest.fn(async () => {
         return testOIDCToken;
@@ -531,17 +533,49 @@ describe("RoomWidgetClient", () => {
                 ).rejects.toThrow();
             });
 
-            it("updates delayed events", async () => {
+            it.each([UpdateDelayedEventAction.Cancel, UpdateDelayedEventAction.Restart, UpdateDelayedEventAction.Send])(
+                "can %s scheduled delayed events (action in parameter)",
+                async (action: UpdateDelayedEventAction) => {
+                    await makeClient({ updateDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                    expect(widgetApi.requestCapability).toHaveBeenCalledWith(
+                        MatrixCapabilities.MSC4157UpdateDelayedEvent,
+                    );
+                    await client._unstable_updateDelayedEvent("id", action);
+                    let updateDelayedEvent: (delayId: string) => Promise<unknown>;
+                    switch (action) {
+                        case UpdateDelayedEventAction.Cancel:
+                            updateDelayedEvent = widgetApi.cancelScheduledDelayedEvent;
+                            break;
+                        case UpdateDelayedEventAction.Restart:
+                            updateDelayedEvent = widgetApi.cancelScheduledDelayedEvent;
+                            break;
+                        case UpdateDelayedEventAction.Send:
+                            updateDelayedEvent = widgetApi.sendScheduledDelayedEvent;
+                            break;
+                    }
+                    expect(updateDelayedEvent).toHaveBeenCalledWith("id");
+                },
+            );
+
+            it("can cancel scheduled delayed events (action in method)", async () => {
                 await makeClient({ updateDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
                 expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157UpdateDelayedEvent);
-                for (const action of [
-                    UpdateDelayedEventAction.Cancel,
-                    UpdateDelayedEventAction.Restart,
-                    UpdateDelayedEventAction.Send,
-                ]) {
-                    await client._unstable_updateDelayedEvent("id", action);
-                    expect(widgetApi.updateDelayedEvent).toHaveBeenCalledWith("id", action);
-                }
+                await client._unstable_cancelScheduledDelayedEvent("id");
+                expect(widgetApi.cancelScheduledDelayedEvent).toHaveBeenCalledWith("id");
+            });
+
+            it("can restart scheduled delayed events (action in method)", async () => {
+                await makeClient({ updateDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157UpdateDelayedEvent);
+                await client._unstable_restartScheduledDelayedEvent("id");
+                expect(widgetApi.restartScheduledDelayedEvent).toHaveBeenCalledWith("id");
+            });
+
+            it("can send scheduled delayed events (action in method)", async () => {
+                await makeClient({ updateDelayedEvents: true, sendEvent: ["org.matrix.rageshake_request"] });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4157UpdateDelayedEvent);
+                await client._unstable_sendScheduledDelayedEvent("id");
+                expect(widgetApi.sendScheduledDelayedEvent).toHaveBeenCalledWith("id");
             });
         });
 
@@ -583,6 +617,13 @@ describe("RoomWidgetClient", () => {
                         "Server does not support",
                     );
                 }
+                for (const updateDelayedEvent of [
+                    client._unstable_cancelScheduledDelayedEvent,
+                    client._unstable_restartScheduledDelayedEvent,
+                    client._unstable_sendScheduledDelayedEvent,
+                ]) {
+                    await expect(updateDelayedEvent.call(client, "id")).rejects.toThrow("Server does not support");
+                }
             });
         });
     });

spec/unit/http-api/__snapshots__/index.spec.ts.snap

@@ -1,4 +1,4 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
 
 exports[`MatrixHttpApi should return expected object from \`getContentUri\` 1`] = `
 {

spec/unit/http-api/fetch.spec.ts

@@ -375,7 +375,7 @@ describe("FetchHttpApi", () => {
                             refreshToken,
                             onlyData: true,
                         });
-                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
+                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toEqual(
                             unknownTokenErr,
                         );
                         expect(tokenRefreshFunction).toHaveBeenCalledWith(refreshToken);
@@ -397,7 +397,7 @@ describe("FetchHttpApi", () => {
                             refreshToken,
                             onlyData: true,
                         });
-                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
+                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toEqual(
                             unknownTokenErr,
                         );
                         expect(tokenRefreshFunction).toHaveBeenCalledWith(refreshToken);

spec/unit/matrix-client.spec.ts

@@ -801,6 +801,10 @@ describe("MatrixClient", function () {
             await expect(
                 client._unstable_updateDelayedEvent("anyDelayId", UpdateDelayedEventAction.Send),
             ).rejects.toThrow(errorMessage);
+
+            await expect(client._unstable_cancelScheduledDelayedEvent("anyDelayId")).rejects.toThrow(errorMessage);
+            await expect(client._unstable_restartScheduledDelayedEvent("anyDelayId")).rejects.toThrow(errorMessage);
+            await expect(client._unstable_sendScheduledDelayedEvent("anyDelayId")).rejects.toThrow(errorMessage);
         });
 
         it("works with null threadId", async () => {
@@ -1053,34 +1057,193 @@ describe("MatrixClient", function () {
             );
         });
 
-        it("can look up delayed events", async () => {
+        describe("lookups", () => {
+            const statuses = [undefined, "scheduled" as const, "finalised" as const];
+            const delayIds = [undefined, "dxyz", ["d123"], ["d456", "d789"]];
+            const inputs = statuses.flatMap((status) =>
+                delayIds.map((delayId) => [status, delayId] as [(typeof statuses)[0], (typeof delayIds)[0]]),
+            );
+            it.each(inputs)("can look up delayed events (status = %s, delayId = %s)", async (status, delayId) => {
+                httpLookups = [
+                    {
+                        method: "GET",
+                        prefix: unstableMSC4140Prefix,
+                        path: "/delayed_events",
+                        expectQueryParams: {
+                            status,
+                            delay_id: delayId,
+                        },
+                        data: [],
+                    },
+                ];
+
+                await client._unstable_getDelayedEvents(status, delayId);
+            });
+        });
+
+        it.each([UpdateDelayedEventAction.Cancel, UpdateDelayedEventAction.Restart, UpdateDelayedEventAction.Send])(
+            "can %s scheduled delayed events (action in request body)",
+            async (action: UpdateDelayedEventAction) => {
+                const delayId = "id";
+                httpLookups = [
+                    {
+                        method: "POST",
+                        prefix: unstableMSC4140Prefix,
+                        path: `/delayed_events/${encodeURIComponent(delayId)}`,
+                        data: {
+                            action,
+                        },
+                    },
+                ];
+
+                await client._unstable_updateDelayedEvent(delayId, action);
+            },
+        );
+
+        it.each([UpdateDelayedEventAction.Cancel, UpdateDelayedEventAction.Restart, UpdateDelayedEventAction.Send])(
+            "can %s scheduled delayed events (action in request body fallback when auth required)",
+            async (action: UpdateDelayedEventAction) => {
+                const delayId = "id";
+                const baseLookup = {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}`,
+                };
+                httpLookups = [
+                    {
+                        ...baseLookup,
+                        error: {
+                            httpStatus: 401,
+                            errcode: "M_MISSING_TOKEN",
+                        },
+                    },
+                    {
+                        ...baseLookup,
+                        data: {
+                            action,
+                        },
+                    },
+                ];
+
+                await client._unstable_updateDelayedEvent(delayId, action);
+            },
+        );
+
+        it("can cancel scheduled delayed events (action in request path)", async () => {
+            const delayId = "id";
             httpLookups = [
                 {
-                    method: "GET",
+                    method: "POST",
                     prefix: unstableMSC4140Prefix,
-                    path: "/delayed_events",
-                    data: [],
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/cancel`,
                 },
             ];
 
-            await client._unstable_getDelayedEvents();
+            await client._unstable_cancelScheduledDelayedEvent(delayId);
         });
 
-        it("can update delayed events", async () => {
+        it("can restart scheduled delayed events (action in request path)", async () => {
             const delayId = "id";
-            const action = UpdateDelayedEventAction.Restart;
             httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/restart`,
+                },
+            ];
+
+            await client._unstable_restartScheduledDelayedEvent(delayId);
+        });
+
+        it("can send scheduled delayed events (action in request path)", async () => {
+            const delayId = "id";
+            httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/send`,
+                },
+            ];
+
+            await client._unstable_sendScheduledDelayedEvent(delayId);
+        });
+
+        it("can cancel scheduled delayed events (action in request path fallback when unsupported)", async () => {
+            const delayId = "id";
+            httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/cancel`,
+                    error: {
+                        httpStatus: 400,
+                        errcode: "M_UNRECOGNIZED",
+                    },
+                },
                 {
                     method: "POST",
                     prefix: unstableMSC4140Prefix,
                     path: `/delayed_events/${encodeURIComponent(delayId)}`,
                     data: {
-                        action,
+                        action: UpdateDelayedEventAction.Cancel,
                     },
                 },
             ];
 
-            await client._unstable_updateDelayedEvent(delayId, action);
+            await client._unstable_cancelScheduledDelayedEvent(delayId);
+            expect(httpLookups).toHaveLength(0);
+        });
+
+        it("can restart scheduled delayed events (action in request path fallback when unsupported)", async () => {
+            const delayId = "id";
+            httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/restart`,
+                    error: {
+                        httpStatus: 400,
+                        errcode: "M_UNRECOGNIZED",
+                    },
+                },
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}`,
+                    data: {
+                        action: UpdateDelayedEventAction.Restart,
+                    },
+                },
+            ];
+
+            await client._unstable_restartScheduledDelayedEvent(delayId);
+            expect(httpLookups).toHaveLength(0);
+        });
+
+        it("can send scheduled delayed events (action in request path fallback when unsupported)", async () => {
+            const delayId = "id";
+            httpLookups = [
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}/send`,
+                    error: {
+                        httpStatus: 400,
+                        errcode: "M_UNRECOGNIZED",
+                    },
+                },
+                {
+                    method: "POST",
+                    prefix: unstableMSC4140Prefix,
+                    path: `/delayed_events/${encodeURIComponent(delayId)}`,
+                    data: {
+                        action: UpdateDelayedEventAction.Send,
+                    },
+                },
+            ];
+
+            await client._unstable_sendScheduledDelayedEvent(delayId);
+            expect(httpLookups).toHaveLength(0);
         });
     });
 

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" };
 
@@ -47,11 +64,293 @@ 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].slotDescription.id).toEqual("");
             expect(sess?.memberships[0].scope).toEqual("m.room");
@@ -60,149 +359,67 @@ describe("MatrixRTCSession", () => {
             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]);
-            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);
         });
     });
 
@@ -306,6 +523,9 @@ describe("MatrixRTCSession", () => {
             client.sendEvent = sendEventMock;
 
             client._unstable_updateDelayedEvent = jest.fn();
+            client._unstable_cancelScheduledDelayedEvent = jest.fn();
+            client._unstable_restartScheduledDelayedEvent = jest.fn();
+            client._unstable_sendScheduledDelayedEvent = jest.fn();
 
             mockRoom = makeMockRoom([]);
             sess = MatrixRTCSession.sessionForRoom(client, mockRoom, callSession);
@@ -329,6 +549,12 @@ describe("MatrixRTCSession", () => {
             expect(sess!.isJoined()).toEqual(true);
         });
 
+        it("uses the sticky events membership manager implementation", () => {
+            sess!.joinRoomSession([mockFocus], mockFocus, { unstableSendStickyEvents: true });
+            expect(sess!.isJoined()).toEqual(true);
+            expect(sess!["membershipManager"] instanceof StickyEventMembershipManager).toEqual(true);
+        });
+
         it("sends a notification when starting a call and emit DidSendCallNotification", async () => {
             // Simulate a join, including the update to the room state
             // Ensure sendEvent returns event IDs so the DidSendCallNotification payload includes them

spec/unit/matrixrtc/MatrixRTCSessionManager.spec.ts

@@ -14,136 +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

@@ -23,6 +23,7 @@ import {
     MatrixError,
     UnsupportedDelayedEventsEndpointError,
     type Room,
+    MAX_STICKY_DURATION_MS,
 } from "../../../src";
 import {
     MembershipManagerEvent,
@@ -32,7 +33,7 @@ import {
     type LivekitFocusSelection,
 } from "../../../src/matrixrtc";
 import { makeMockClient, makeMockRoom, membershipTemplate, mockCallMembership, type MockClient } from "./mocks";
-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.
@@ -93,7 +94,12 @@ 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_cancelScheduledDelayedEvent as Mock<any>).mockResolvedValue(undefined);
+        (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockResolvedValue(undefined);
+        (client._unstable_sendScheduledDelayedEvent 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(() => {
@@ -119,7 +125,9 @@ describe("MembershipManager", () => {
             it("sends a membership event and schedules delayed leave when joining a call", async () => {
                 // Spys/Mocks
 
-                const updateDelayedEventHandle = createAsyncHandle<void>(client._unstable_updateDelayedEvent as Mock);
+                const restartScheduledDelayedEventHandle = createAsyncHandle<void>(
+                    client._unstable_restartScheduledDelayedEvent as Mock,
+                );
 
                 // Test
                 const memberManager = new MembershipManager(undefined, room, client, callSession);
@@ -140,7 +148,7 @@ describe("MembershipManager", () => {
                     },
                     "_@alice:example.org_AAAAAAA_m.call",
                 );
-                updateDelayedEventHandle.resolve?.();
+                restartScheduledDelayedEventHandle.resolve?.();
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
                     room.roomId,
                     { delay: 8000 },
@@ -151,53 +159,16 @@ describe("MembershipManager", () => {
                 expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
             });
 
-            it("sends a rtc membership event when using `useRtcMemberFormat`", async () => {
-                // Spys/Mocks
-
-                const updateDelayedEventHandle = createAsyncHandle<void>(client._unstable_updateDelayedEvent as Mock);
-
-                // Test
-                const memberManager = new MembershipManager({ useRtcMemberFormat: true }, room, client, callSession);
-                memberManager.join([], focus);
-                // expects
-                await waitForMockCall(client.sendStateEvent, Promise.resolve({ event_id: "id" }));
-                expect(client.sendStateEvent).toHaveBeenCalledWith(
-                    room.roomId,
-                    "org.matrix.msc4143.rtc.member",
-                    {
-                        application: { type: "m.call" },
-                        member: {
-                            user_id: "@alice:example.org",
-                            id: "_@alice:example.org_AAAAAAA_m.call",
-                            device_id: "AAAAAAA",
-                        },
-                        slot_id: "m.call#",
-                        rtc_transports: [focus],
-                        versions: [],
-                    },
-                    "_@alice:example.org_AAAAAAA_m.call",
-                );
-                updateDelayedEventHandle.resolve?.();
-                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
-                    room.roomId,
-                    { delay: 8000 },
-                    "org.matrix.msc4143.rtc.member",
-                    {},
-                    "_@alice:example.org_AAAAAAA_m.call",
-                );
-                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);
-            });
-
             it("reschedules delayed leave event if sending state cancels it", async () => {
                 const memberManager = new MembershipManager(undefined, room, client, callSession);
                 const waitForSendState = waitForMockCall(client.sendStateEvent);
-                const waitForUpdateDelaye = waitForMockCallOnce(
-                    client._unstable_updateDelayedEvent,
+                const waitForRestartScheduledDelayedEvent = waitForMockCallOnce(
+                    client._unstable_restartScheduledDelayedEvent,
                     Promise.reject(new MatrixError({ errcode: "M_NOT_FOUND" })),
                 );
                 memberManager.join([focus], focusActive);
                 await waitForSendState;
-                await waitForUpdateDelaye;
+                await waitForRestartScheduledDelayedEvent;
                 await jest.advanceTimersByTimeAsync(1);
                 // Once for the initial event and once because of the errcode: "M_NOT_FOUND"
                 // Different to "sends a membership event and schedules delayed leave when joining a call" where its only called once (1)
@@ -213,7 +184,7 @@ describe("MembershipManager", () => {
                     if (useOwnedStateEvents) {
                         room.getVersion = jest.fn().mockReturnValue("org.matrix.msc3757.default");
                     }
-                    const updatedDelayedEvent = waitForMockCall(client._unstable_updateDelayedEvent);
+                    const restartScheduledDelayedEvent = waitForMockCall(client._unstable_restartScheduledDelayedEvent);
                     const sentDelayedState = waitForMockCall(
                         client._unstable_sendDelayedStateEvent,
                         Promise.resolve({
@@ -299,13 +270,13 @@ describe("MembershipManager", () => {
                     await sentDelayedState;
 
                     // should have prepared the heartbeat to keep delaying the leave event while still connected
-                    await updatedDelayedEvent;
-                    expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(1);
+                    await restartScheduledDelayedEvent;
+                    expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(1);
 
                     // ensures that we reach the code that schedules the timeout for the next delay update before we advance the timers.
                     await jest.advanceTimersByTimeAsync(5000);
                     // should update delayed disconnect
-                    expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(2);
+                    expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(2);
                 }
 
                 it("sends a membership event after rate limits during delayed event setup when joining a call", async () => {
@@ -377,7 +348,7 @@ describe("MembershipManager", () => {
             //   (onRTCSessionMemberUpdate)
             // - Only then do we resolve the sending of the delayed event.
             // - We test that the manager acknowledges the leave and sends a new membership state event.
-            (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValueOnce(
+            (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockRejectedValueOnce(
                 new MatrixError({ errcode: "M_NOT_FOUND" }),
             );
 
@@ -438,17 +409,17 @@ describe("MembershipManager", () => {
             manager.join([focus]);
             await jest.advanceTimersByTimeAsync(1);
             await manager.leave();
-            expect(client._unstable_updateDelayedEvent).toHaveBeenLastCalledWith("id", "send");
+            expect(client._unstable_sendScheduledDelayedEvent).toHaveBeenLastCalledWith("id");
             expect(client.sendStateEvent).toHaveBeenCalled();
         });
         it("send leave event when leave is called and resolving delayed leave fails", async () => {
             const manager = new MembershipManager({}, room, client, callSession);
             manager.join([focus]);
             await jest.advanceTimersByTimeAsync(1);
-            (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValue("unknown");
+            (client._unstable_sendScheduledDelayedEvent as Mock<any>).mockRejectedValue("unknown");
             await manager.leave();
 
-            // We send a normal leave event since we failed using updateDelayedEvent with the "send" action.
+            // We send a normal leave event since we failed using sendScheduledDelayedEvent.
             expect(client.sendStateEvent).toHaveBeenLastCalledWith(
                 room.roomId,
                 "org.matrix.msc3401.call.member",
@@ -472,6 +443,9 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).not.toHaveBeenCalled();
             expect(client._unstable_sendDelayedStateEvent).not.toHaveBeenCalled();
             expect(client._unstable_updateDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_cancelScheduledDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_restartScheduledDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_sendScheduledDelayedEvent).not.toHaveBeenCalled();
         });
         it("does nothing if own membership still present", async () => {
             const manager = new MembershipManager({}, room, client, callSession);
@@ -481,6 +455,9 @@ describe("MembershipManager", () => {
             // reset all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
             (client.sendStateEvent as Mock).mockClear();
             (client._unstable_updateDelayedEvent as Mock).mockClear();
+            (client._unstable_cancelScheduledDelayedEvent as Mock).mockClear();
+            (client._unstable_restartScheduledDelayedEvent as Mock).mockClear();
+            (client._unstable_sendScheduledDelayedEvent as Mock).mockClear();
             (client._unstable_sendDelayedStateEvent as Mock).mockClear();
 
             await manager.onRTCSessionMemberUpdate([
@@ -496,6 +473,9 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).not.toHaveBeenCalled();
             expect(client._unstable_sendDelayedStateEvent).not.toHaveBeenCalled();
             expect(client._unstable_updateDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_cancelScheduledDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_restartScheduledDelayedEvent).not.toHaveBeenCalled();
+            expect(client._unstable_sendScheduledDelayedEvent).not.toHaveBeenCalled();
         });
         it("recreates membership if it is missing", async () => {
             const manager = new MembershipManager({}, room, client, callSession);
@@ -503,7 +483,7 @@ describe("MembershipManager", () => {
             await jest.advanceTimersByTimeAsync(1);
             // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
             (client.sendStateEvent as Mock).mockClear();
-            (client._unstable_updateDelayedEvent as Mock).mockClear();
+            (client._unstable_restartScheduledDelayedEvent as Mock).mockClear();
             (client._unstable_sendDelayedStateEvent as Mock).mockClear();
 
             // Our own membership is removed:
@@ -512,7 +492,7 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).toHaveBeenCalled();
             expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalled();
 
-            expect(client._unstable_updateDelayedEvent).toHaveBeenCalled();
+            expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalled();
         });
 
         it("updates the UpdateExpiry entry in the action scheduler", async () => {
@@ -521,10 +501,10 @@ describe("MembershipManager", () => {
             await jest.advanceTimersByTimeAsync(1);
             // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
             (client.sendStateEvent as Mock).mockClear();
-            (client._unstable_updateDelayedEvent as Mock).mockClear();
+            (client._unstable_restartScheduledDelayedEvent as Mock).mockClear();
             (client._unstable_sendDelayedStateEvent as Mock).mockClear();
 
-            (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValueOnce(
+            (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockRejectedValueOnce(
                 new MatrixError({ errcode: "M_NOT_FOUND" }),
             );
 
@@ -537,7 +517,7 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).toHaveBeenCalled();
             expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalled();
 
-            expect(client._unstable_updateDelayedEvent).toHaveBeenCalled();
+            expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalled();
             expect(manager.status).toBe(Status.Connected);
         });
     });
@@ -557,17 +537,17 @@ describe("MembershipManager", () => {
 
             // The first call is from checking id the server deleted the delayed event
             // so it does not need a `advanceTimersByTime`
-            expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(1);
+            expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(1);
             // TODO: Check that update delayed event is called with the correct HTTP request timeout
-            // expect(client._unstable_updateDelayedEvent).toHaveBeenLastCalledWith("id", 10_000, { localTimeoutMs: 20_000 });
+            // expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenLastCalledWith("id", 10_000, { localTimeoutMs: 20_000 });
 
             for (let i = 2; i <= 12; i++) {
                 // flush promises before advancing the timers to make sure schedulers are setup
                 await jest.advanceTimersByTimeAsync(10_000);
 
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(i);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(i);
                 // TODO: Check that update delayed event is called with the correct HTTP request timeout
-                // expect(client._unstable_updateDelayedEvent).toHaveBeenLastCalledWith("id", 10_000, { localTimeoutMs: 20_000 });
+                // expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenLastCalledWith("id", 10_000, { localTimeoutMs: 20_000 });
             }
         });
 
@@ -715,7 +695,7 @@ describe("MembershipManager", () => {
         });
         describe("retries sending update delayed leave event restart", () => {
             it("resends the initial check delayed update event", async () => {
-                (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValue(
+                (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockRejectedValue(
                     new MatrixError(
                         { errcode: "M_LIMIT_EXCEEDED" },
                         429,
@@ -729,17 +709,17 @@ describe("MembershipManager", () => {
 
                 // Hit rate limit
                 await jest.advanceTimersByTimeAsync(1);
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(1);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(1);
 
                 // Hit second rate limit.
                 await jest.advanceTimersByTimeAsync(1000);
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(2);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(2);
 
                 // Setup resolve
-                (client._unstable_updateDelayedEvent as Mock<any>).mockResolvedValue(undefined);
+                (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockResolvedValue(undefined);
                 await jest.advanceTimersByTimeAsync(1000);
 
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(3);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(3);
                 expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
             });
         });
@@ -768,7 +748,7 @@ describe("MembershipManager", () => {
         // because legacy does not have a retry limit and no mechanism to communicate unrecoverable errors.
         it("throws, when reaching maximum number of retries", async () => {
             const delayEventRestartError = jest.fn();
-            (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValue(
+            (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockRejectedValue(
                 new MatrixError(
                     { errcode: "M_LIMIT_EXCEEDED" },
                     429,
@@ -842,11 +822,11 @@ describe("MembershipManager", () => {
             manager.join([focus], focusActive);
             try {
                 // Let the scheduler run one iteration so that we can send the join state event
-                await waitForMockCall(client._unstable_updateDelayedEvent);
+                await waitForMockCall(client._unstable_restartScheduledDelayedEvent);
 
                 // We never resolve the delayed event so that we can test the probablyLeft event.
                 // This simulates the case where the server does not respond to the delayed event.
-                client._unstable_updateDelayedEvent = jest.fn(() => stuckPromise);
+                client._unstable_restartScheduledDelayedEvent = jest.fn(() => stuckPromise);
                 expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
                 expect(manager.status).toBe(Status.Connected);
                 expect(probablyLeftEmit).not.toHaveBeenCalledWith(true);
@@ -856,18 +836,18 @@ describe("MembershipManager", () => {
                 await jest.advanceTimersByTimeAsync(5000);
                 // No emission after 5s
                 expect(probablyLeftEmit).not.toHaveBeenCalledWith(true);
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(1);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(1);
 
                 await jest.advanceTimersByTimeAsync(4999);
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(3);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(3);
                 expect(probablyLeftEmit).not.toHaveBeenCalledWith(true);
 
                 // Reset mocks before we setup the next delayed event restart by advancing the timers 1 more ms.
-                (client._unstable_updateDelayedEvent as Mock<any>).mockResolvedValue({});
+                (client._unstable_restartScheduledDelayedEvent as Mock<any>).mockResolvedValue({});
 
                 // Emit after 10s
                 await jest.advanceTimersByTimeAsync(1);
-                expect(client._unstable_updateDelayedEvent).toHaveBeenCalledTimes(4);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(4);
                 expect(probablyLeftEmit).toHaveBeenCalledWith(true);
 
                 // Mock a sync which does not include our own membership
@@ -921,6 +901,63 @@ describe("MembershipManager", () => {
             expect(client.sendStateEvent).toHaveBeenCalledTimes(0);
         });
     });
+
+    describe("StickyEventMembershipManager", () => {
+        beforeEach(() => {
+            // Provide a default mock that is like the default "non error" server behaviour.
+            (client._unstable_sendStickyDelayedEvent as Mock<any>).mockResolvedValue({ delay_id: "id" });
+            (client._unstable_sendStickyEvent as Mock<any>).mockResolvedValue(undefined);
+        });
+
+        describe("join()", () => {
+            describe("sends an rtc membership event", () => {
+                it("sends a membership event and schedules delayed leave when joining a call", async () => {
+                    const restartScheduledDelayedEventHandle = createAsyncHandle<void>(
+                        client._unstable_restartScheduledDelayedEvent 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",
+                        },
+                    );
+                    restartScheduledDelayedEventHandle.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", () => {

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 +52,11 @@ export type MockClient = Pick<
     | "sendStateEvent"
     | "_unstable_sendDelayedStateEvent"
     | "_unstable_updateDelayedEvent"
+    | "_unstable_cancelScheduledDelayedEvent"
+    | "_unstable_restartScheduledDelayedEvent"
+    | "_unstable_sendScheduledDelayedEvent"
+    | "_unstable_sendStickyEvent"
+    | "_unstable_sendStickyDelayedEvent"
     | "cancelPendingEvent"
 >;
 /**
@@ -64,16 +70,23 @@ export function makeMockClient(userId: string, deviceId: string): MockClient {
         sendStateEvent: jest.fn(),
         cancelPendingEvent: jest.fn(),
         _unstable_updateDelayedEvent: jest.fn(),
+        _unstable_cancelScheduledDelayedEvent: jest.fn(),
+        _unstable_restartScheduledDelayedEvent: jest.fn(),
+        _unstable_sendScheduledDelayedEvent: 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 +94,16 @@ 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 +147,7 @@ export function makeMockEvent(
     roomId: string | undefined,
     content: any,
     timestamp?: number,
+    stateKey?: string,
 ): MatrixEvent {
     return {
         getType: jest.fn().mockReturnValue(type),
@@ -137,12 +156,28 @@ 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/poll.spec.ts

@@ -127,15 +127,17 @@ describe("Poll", () => {
 
         it("waits for existing relations request to finish when getting responses", async () => {
             const poll = new Poll(basePollStartEvent, mockClient, room);
+            // @ts-expect-error TS2769
+            const spy = jest.spyOn(poll, "fetchResponses");
             const firstResponsePromise = poll.getResponses();
             const secondResponsePromise = poll.getResponses();
             await firstResponsePromise;
-            expect(firstResponsePromise).toEqual(secondResponsePromise);
             await secondResponsePromise;
+            expect(spy).toHaveBeenCalledTimes(1);
             expect(mockClient.relations).toHaveBeenCalledTimes(1);
         });
 
-        it("filters relations for relevent response events", async () => {
+        it("filters relations for relevant response events", async () => {
             const replyEvent = makeRelatedEvent({ type: "m.room.message" });
             const stableResponseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.stable! });
             const unstableResponseEvent = makeRelatedEvent({ type: M_POLL_RESPONSE.unstable });

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

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

spec/unit/models/room.spec.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { Direction, type MatrixClient, MatrixEvent, Room } from "../../../src";
+import { Direction, EventType, type MatrixClient, MatrixEvent, Room } from "../../../src";
 import type { MockedObject } from "jest-mock";
 
 const CREATOR_USER_ID = "@creator:example.org";
@@ -185,4 +185,71 @@ describe("Room", () => {
             expectRedacted(messageEvents, room, false);
         });
     });
+
+    it("should ignore invalid m.room.name events", async () => {
+        const mockClient = createMockClient();
+        const room = new Room("!room:example.org", mockClient, CREATOR_USER_ID);
+        const invalidNameEvent = new MatrixEvent({
+            type: EventType.RoomName,
+            content: {
+                name: { invalid: 123 },
+            },
+            state_key: "",
+            event_id: "$123",
+            room_id: room.roomId,
+            sender: CREATOR_USER_ID,
+        });
+
+        // Set up the room
+        room.currentState.setStateEvents([invalidNameEvent]);
+        room.recalculate();
+
+        expect(room.name).toEqual("Empty room");
+    });
+
+    describe("getAltAliases()", () => {
+        it("should ignore invalid events", async () => {
+            const mockClient = createMockClient();
+            const room = new Room("!room:example.org", mockClient, CREATOR_USER_ID);
+            const invalidAliasEvent = new MatrixEvent({
+                type: EventType.RoomCanonicalAlias,
+                content: {
+                    alt_aliases: [123, "#foo:bar"],
+                },
+                state_key: "",
+                event_id: "$123",
+                room_id: room.roomId,
+                sender: CREATOR_USER_ID,
+            });
+
+            // Set up the room
+            room.currentState.setStateEvents([invalidAliasEvent]);
+            room.recalculate();
+
+            expect(room.getAltAliases()).toEqual(["#foo:bar"]);
+        });
+    });
+
+    describe("calculateRoomName()", () => {
+        it("should ignore empty m.room.name 'name' field", async () => {
+            const mockClient = createMockClient();
+            const room = new Room("!room:example.org", mockClient, CREATOR_USER_ID);
+            const event = new MatrixEvent({
+                type: EventType.RoomName,
+                content: {
+                    name: "",
+                },
+                state_key: "",
+                event_id: "$123",
+                room_id: room.roomId,
+                sender: CREATOR_USER_ID,
+            });
+
+            // Set up the room
+            room.currentState.setStateEvents([event]);
+            room.recalculate();
+
+            expect(room.name).not.toEqual("");
+        });
+    });
 });

spec/unit/room.spec.ts

@@ -19,7 +19,7 @@ limitations under the License.
  */
 
 import { mocked } from "jest-mock";
-import { M_POLL_KIND_DISCLOSED, M_POLL_RESPONSE, M_POLL_START, type Optional, PollStartEvent } from "matrix-events-sdk";
+import { M_POLL_KIND_DISCLOSED, M_POLL_RESPONSE, M_POLL_START, PollStartEvent } from "matrix-events-sdk";
 
 import * as utils from "../test-utils/test-utils";
 import { emitPromise, type IMessageOpts } from "../test-utils/test-utils";
@@ -197,8 +197,8 @@ describe("Room", function () {
 
     const addRoomThreads = (
         room: Room,
-        thread1EventTs: Optional<number>,
-        thread2EventTs: Optional<number>,
+        thread1EventTs?: number,
+        thread2EventTs?: number,
     ): { thread1?: Thread; thread2?: Thread } => {
         const result: { thread1?: Thread; thread2?: Thread } = {};
 
@@ -4159,7 +4159,7 @@ describe("Room", function () {
         });
 
         it("when there is only one thread, it should return this one", () => {
-            const { thread1 } = addRoomThreads(room, 23, null);
+            const { thread1 } = addRoomThreads(room, 23);
             expect(room.getLastThread()).toBe(thread1);
         });
 

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

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type Mocked, type SpyInstance } from "jest-mock";
+import { type Mocked } from "jest-mock";
 import * as RustSdkCryptoJs from "@matrix-org/matrix-sdk-crypto-wasm";
 import { type OlmMachine } from "@matrix-org/matrix-sdk-crypto-wasm";
 import fetchMock from "fetch-mock-jest";
@@ -211,14 +211,14 @@ describe("PerSessionKeyBackupDownloader", () => {
             fetchMock.get(`path:/_matrix/client/v3/room_keys/keys/!roomA/sessionA1`, mockCipherKey);
 
             // @ts-ignore access to private function
-            const spy: SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
+            const spy: jest.SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
 
             const expectImported = expectSessionImported("!roomA", "sessionA1");
 
             downloader.onDecryptionKeyMissingError("!roomA", "sessionA0");
             await jest.runAllTimersAsync();
             expect(spy).toHaveBeenCalledTimes(1);
-            expect(spy).toHaveLastReturnedWith(Promise.resolve({ ok: false, error: "MISSING_DECRYPTION_KEY" }));
+            await expect(spy.mock.results[0].value).rejects.toThrow("MISSING_DECRYPTION_KEY");
 
             downloader.onDecryptionKeyMissingError("!roomA", "sessionA1");
             await jest.runAllTimersAsync();
@@ -237,7 +237,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             });
 
             // @ts-ignore access to private function
-            const spy: SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
+            const spy: jest.SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
 
             downloader.onDecryptionKeyMissingError("!roomA", "sessionA0");
             await jest.runAllTimersAsync();
@@ -297,7 +297,7 @@ describe("PerSessionKeyBackupDownloader", () => {
     });
 
     describe("Given no usable backup available", () => {
-        let getConfigSpy: SpyInstance;
+        let getConfigSpy: jest.SpyInstance;
 
         beforeEach(async () => {
             mockRustBackupManager.getActiveBackupVersion.mockResolvedValue(null);
@@ -318,7 +318,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             await jest.runAllTimersAsync();
 
             expect(getConfigSpy).toHaveBeenCalledTimes(1);
-            expect(getConfigSpy).toHaveReturnedWith(Promise.resolve(null));
+            await expect(getConfigSpy.mock.results[0].value).resolves.toEqual(null);
 
             // isKeyBackupDownloadConfigured remains false
             expect(downloader.isKeyBackupDownloadConfigured()).toBe(false);
@@ -336,7 +336,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             await jest.runAllTimersAsync();
 
             expect(getConfigSpy).toHaveBeenCalledTimes(1);
-            expect(getConfigSpy).toHaveReturnedWith(Promise.resolve(null));
+            await expect(getConfigSpy.mock.results[0].value).resolves.toEqual(null);
 
             // isKeyBackupDownloadConfigured remains false
             expect(downloader.isKeyBackupDownloadConfigured()).toBe(false);
@@ -355,7 +355,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             await jest.runAllTimersAsync();
 
             expect(getConfigSpy).toHaveBeenCalledTimes(1);
-            expect(getConfigSpy).toHaveReturnedWith(Promise.resolve(null));
+            await expect(getConfigSpy.mock.results[0].value).resolves.toEqual(null);
 
             // isKeyBackupDownloadConfigured remains false
             expect(downloader.isKeyBackupDownloadConfigured()).toBe(false);
@@ -377,7 +377,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             await jest.runAllTimersAsync();
 
             expect(getConfigSpy).toHaveBeenCalledTimes(1);
-            expect(getConfigSpy).toHaveReturnedWith(Promise.resolve(null));
+            await expect(getConfigSpy.mock.results[0].value).resolves.toEqual(null);
 
             // isKeyBackupDownloadConfigured remains false
             expect(downloader.isKeyBackupDownloadConfigured()).toBe(false);
@@ -399,7 +399,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             await jest.runAllTimersAsync();
 
             expect(getConfigSpy).toHaveBeenCalledTimes(1);
-            expect(getConfigSpy).toHaveReturnedWith(Promise.resolve(null));
+            await expect(getConfigSpy.mock.results[0].value).resolves.toEqual(null);
 
             // isKeyBackupDownloadConfigured remains false
             expect(downloader.isKeyBackupDownloadConfigured()).toBe(false);
@@ -488,7 +488,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             const originalImplementation = downloader.queryKeyBackup.bind(downloader);
 
             // @ts-ignore access to private function
-            const keyQuerySpy: SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
+            const keyQuerySpy: jest.SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
             const rateDeferred = Promise.withResolvers<void>();
 
             keyQuerySpy.mockImplementation(
@@ -542,7 +542,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             const originalImplementation = downloader.queryKeyBackup.bind(downloader);
 
             // @ts-ignore
-            const keyQuerySpy: SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
+            const keyQuerySpy: jest.SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
             const errorDeferred = Promise.withResolvers<void>();
 
             keyQuerySpy.mockImplementation(
@@ -606,7 +606,7 @@ describe("PerSessionKeyBackupDownloader", () => {
             });
 
             // @ts-ignore access to private function
-            const keyQuerySpy: SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
+            const keyQuerySpy: jest.SpyInstance = jest.spyOn(downloader, "queryKeyBackup");
 
             downloader.onDecryptionKeyMissingError("!roomA", "sessionA0");
             downloader.onDecryptionKeyMissingError("!roomA", "sessionA1");

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

@@ -1,4 +1,4 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
 
 exports[`RustCrypto importing and exporting room keys should import and export keys 1`] = `
 {

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

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

spec/unit/timeline-window.spec.ts

@@ -98,7 +98,7 @@ function createLinkedTimelines(): [EventTimeline, EventTimeline] {
 describe("TimelineIndex", function () {
     beforeEach(() => {
         jest.clearAllMocks();
-        mockClient.getEventTimeline.mockResolvedValue(undefined);
+        mockClient.getEventTimeline.mockResolvedValue(null);
     });
 
     describe("minIndex", function () {
@@ -193,7 +193,7 @@ describe("TimelineWindow", function () {
 
     beforeEach(() => {
         jest.clearAllMocks();
-        mockClient.getEventTimeline.mockResolvedValue(undefined);
+        mockClient.getEventTimeline.mockResolvedValue(null);
         mockClient.paginateEventTimeline.mockResolvedValue(false);
     });
 

spec/unit/webrtc/groupCall.spec.ts

@@ -187,12 +187,14 @@ describe("Group Call", function () {
         });
 
         it("does not start initializing local call feed twice", () => {
-            const promise1 = groupCall.initLocalCallFeed();
+            // @ts-expect-error TS2769
+            const spy = jest.spyOn(groupCall, "initLocalCallFeedInternal");
+            groupCall.initLocalCallFeed();
             // @ts-ignore Mock
             groupCall.state = GroupCallState.LocalCallFeedUninitialized;
-            const promise2 = groupCall.initLocalCallFeed();
+            groupCall.initLocalCallFeed();
 
-            expect(promise1).toEqual(promise2);
+            expect(spy).toHaveBeenCalledTimes(1);
         });
 
         it("sets state to local call feed uninitialized when getUserMedia() fails", async () => {

spec/unit/webrtc/mediaHandler.spec.ts

@@ -61,10 +61,10 @@ describe("Media Handler", function () {
         expect(mockMediaDevices.getUserMedia).toHaveBeenCalledWith(
             expect.objectContaining({
                 audio: expect.objectContaining({
-                    deviceId: { ideal: FAKE_AUDIO_INPUT_ID },
+                    deviceId: { exact: FAKE_AUDIO_INPUT_ID },
                 }),
                 video: expect.objectContaining({
-                    deviceId: { ideal: FAKE_VIDEO_INPUT_ID },
+                    deviceId: { exact: FAKE_VIDEO_INPUT_ID },
                 }),
             }),
         );
@@ -77,7 +77,7 @@ describe("Media Handler", function () {
         expect(mockMediaDevices.getUserMedia).toHaveBeenCalledWith(
             expect.objectContaining({
                 audio: expect.objectContaining({
-                    deviceId: { ideal: FAKE_AUDIO_INPUT_ID },
+                    deviceId: { exact: FAKE_AUDIO_INPUT_ID },
                 }),
             }),
         );
@@ -109,7 +109,7 @@ describe("Media Handler", function () {
         expect(mockMediaDevices.getUserMedia).toHaveBeenCalledWith(
             expect.objectContaining({
                 video: expect.objectContaining({
-                    deviceId: { ideal: FAKE_VIDEO_INPUT_ID },
+                    deviceId: { exact: FAKE_VIDEO_INPUT_ID },
                 }),
             }),
         );
@@ -122,10 +122,10 @@ describe("Media Handler", function () {
         expect(mockMediaDevices.getUserMedia).toHaveBeenCalledWith(
             expect.objectContaining({
                 audio: expect.objectContaining({
-                    deviceId: { ideal: FAKE_AUDIO_INPUT_ID },
+                    deviceId: { exact: FAKE_AUDIO_INPUT_ID },
                 }),
                 video: expect.objectContaining({
-                    deviceId: { ideal: FAKE_VIDEO_INPUT_ID },
+                    deviceId: { exact: FAKE_VIDEO_INPUT_ID },
                 }),
             }),
         );
@@ -331,6 +331,80 @@ describe("Media Handler", function () {
 
             expect(stream.getVideoTracks().length).toEqual(0);
         });
+
+        it("falls back to ideal deviceId when exact deviceId fails", async () => {
+            // First call with exact should fail
+            mockMediaDevices.getUserMedia
+                .mockRejectedValueOnce(new Error("OverconstrainedError"))
+                .mockImplementation((constraints: MediaStreamConstraints) => {
+                    const stream = new MockMediaStream("local_stream");
+                    if (constraints.audio) {
+                        const track = new MockMediaStreamTrack("audio_track", "audio");
+                        track.settings = { deviceId: FAKE_AUDIO_INPUT_ID };
+                        stream.addTrack(track);
+                    }
+                    return Promise.resolve(stream.typed());
+                });
+
+            const stream = await mediaHandler.getUserMediaStream(true, false);
+
+            // Should have been called twice: once with exact, once with ideal
+            expect(mockMediaDevices.getUserMedia).toHaveBeenCalledTimes(2);
+            expect(mockMediaDevices.getUserMedia).toHaveBeenNthCalledWith(
+                1,
+                expect.objectContaining({
+                    audio: expect.objectContaining({
+                        deviceId: { exact: FAKE_AUDIO_INPUT_ID },
+                    }),
+                }),
+            );
+            expect(mockMediaDevices.getUserMedia).toHaveBeenNthCalledWith(
+                2,
+                expect.objectContaining({
+                    audio: expect.objectContaining({
+                        deviceId: { ideal: FAKE_AUDIO_INPUT_ID },
+                    }),
+                }),
+            );
+            expect(stream).toBeTruthy();
+        });
+
+        it("falls back to ideal deviceId for video when exact fails", async () => {
+            // First call with exact should fail
+            mockMediaDevices.getUserMedia
+                .mockRejectedValueOnce(new Error("OverconstrainedError"))
+                .mockImplementation((constraints: MediaStreamConstraints) => {
+                    const stream = new MockMediaStream("local_stream");
+                    if (constraints.video) {
+                        const track = new MockMediaStreamTrack("video_track", "video");
+                        track.settings = { deviceId: FAKE_VIDEO_INPUT_ID };
+                        stream.addTrack(track);
+                    }
+                    return Promise.resolve(stream.typed());
+                });
+
+            const stream = await mediaHandler.getUserMediaStream(false, true);
+
+            // Should have been called twice: once with exact, once with ideal
+            expect(mockMediaDevices.getUserMedia).toHaveBeenCalledTimes(2);
+            expect(mockMediaDevices.getUserMedia).toHaveBeenNthCalledWith(
+                1,
+                expect.objectContaining({
+                    video: expect.objectContaining({
+                        deviceId: { exact: FAKE_VIDEO_INPUT_ID },
+                    }),
+                }),
+            );
+            expect(mockMediaDevices.getUserMedia).toHaveBeenNthCalledWith(
+                2,
+                expect.objectContaining({
+                    video: expect.objectContaining({
+                        deviceId: { ideal: FAKE_VIDEO_INPUT_ID },
+                    }),
+                }),
+            );
+            expect(stream).toBeTruthy();
+        });
     });
 
     describe("getScreensharingStream", () => {

spec/unit/webrtc/stats/__snapshots__/callFeedStatsReporter.spec.ts.snap

@@ -1,4 +1,4 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Jest Snapshot v1, https://jestjs.io/docs/snapshot-testing
 
 exports[`CallFeedStatsReporter should builds CallFeedReport 1`] = `
 {

src/@types/event.ts

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

src/@types/extensible_events.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type EitherAnd, NamespacedValue, type Optional, UnstableValue } from "matrix-events-sdk";
+import { type EitherAnd, NamespacedValue, UnstableValue } from "matrix-events-sdk";
 
 import { isProvided } from "../extensible_events_v1/utilities.ts";
 
@@ -125,10 +125,7 @@ export type ExtensibleEventType = NamespacedValue<string, string> | string;
  * @param expected - The expected event type.
  * @returns True if the given type matches the expected type.
  */
-export function isEventTypeSame(
-    given: Optional<ExtensibleEventType>,
-    expected: Optional<ExtensibleEventType>,
-): boolean {
+export function isEventTypeSame(given: ExtensibleEventType | null, expected: ExtensibleEventType | null): boolean {
     if (typeof given === "string") {
         if (typeof expected === "string") {
             return expected === given;

src/@types/requests.ts

@@ -20,6 +20,7 @@ import { type IEventWithRoomId, type SearchKey } from "./search.ts";
 import { type IRoomEventFilter } from "../filter.ts";
 import { type Direction } from "../models/event-timeline.ts";
 import { type PushRuleAction } from "./PushRules.ts";
+import { type MatrixError } from "../matrix.ts";
 import { type IRoomEvent } from "../sync-accumulator.ts";
 import { type EventType, type RelationType, type RoomType } from "./event.ts";
 
@@ -136,12 +137,22 @@ type DelayedPartialStateEvent = DelayedPartialTimelineEvent & {
 
 type DelayedPartialEvent = DelayedPartialTimelineEvent | DelayedPartialStateEvent;
 
+export type 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;
 };
 
@@ -287,12 +298,12 @@ export interface IRelationsResponse {
 }
 
 export interface IContextResponse {
-    end: string;
-    start: string;
-    state: IEventWithRoomId[];
-    events_before: IEventWithRoomId[];
-    events_after: IEventWithRoomId[];
-    event: IEventWithRoomId;
+    end?: string;
+    start?: string;
+    state?: IEventWithRoomId[];
+    events_before?: IEventWithRoomId[];
+    events_after?: IEventWithRoomId[];
+    event?: IEventWithRoomId;
 }
 
 export interface IEventsResponse {

src/@types/state_events.ts

@@ -106,7 +106,7 @@ export interface RoomPinnedEventsEventContent {
 
 export interface RoomEncryptionEventContent {
     "algorithm": "m.megolm.v1.aes-sha2";
-    "io.element.msc3414.encrypt_state_events"?: boolean;
+    "io.element.msc4362.encrypt_state_events"?: boolean;
     "rotation_period_ms"?: number;
     "rotation_period_msgs"?: number;
 }

src/NamespacedValue.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type Optional } from "matrix-events-sdk";
-
 /**
  * Represents a simple Matrix namespaced value. This will assume that if a stable prefix
  * is provided that the stable prefix should be used when representing the identifier.
@@ -62,7 +60,7 @@ export class NamespacedValue<S extends string, U extends string> {
 
     // this desperately wants https://github.com/microsoft/TypeScript/pull/26349 at the top level of the class
     // so we can instantiate `NamespacedValue<string, _, _>` as a default type for that namespace.
-    public findIn<T>(obj: any): Optional<T> {
+    public findIn<T>(obj: any): T | undefined {
         let val: T | undefined = undefined;
         if (this.name) {
             val = obj?.[this.name];

src/client.ts

@@ -18,8 +18,6 @@ limitations under the License.
  * This is an internal module. See {@link MatrixClient} for the public class.
  */
 
-import { type Optional } from "matrix-events-sdk";
-
 import type { IDeviceKeys, IOneTimeKey } from "./@types/crypto.ts";
 import { type ISyncStateData, type SetPresence, SyncApi, type SyncApiOptions, SyncState } from "./sync.ts";
 import {
@@ -106,6 +104,7 @@ import { RoomMemberEvent, type RoomMemberEventHandlerMap } from "./models/room-m
 import { type IPowerLevelsContent, type RoomStateEvent, type RoomStateEventHandlerMap } from "./models/room-state.ts";
 import {
     isSendDelayedEventRequestOpts,
+    UpdateDelayedEventAction,
     type DelayedEventInfo,
     type IAddThreePidOnlyBody,
     type IBindThreePidBody,
@@ -130,7 +129,6 @@ import {
     type KnockRoomOpts,
     type SendDelayedEventRequestOpts,
     type SendDelayedEventResponse,
-    type UpdateDelayedEventAction,
 } from "./@types/requests.ts";
 import {
     type AccountDataEvents,
@@ -2408,7 +2406,12 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         const roomId = res.room_id;
         if (opts.acceptSharedHistory && inviter && this.cryptoBackend) {
-            await this.cryptoBackend.maybeAcceptKeyBundle(roomId, inviter);
+            // Try to accept the room key bundle specified in a `m.room_key_bundle` to-device message we (might have) already received.
+            const bundleDownloaded = await this.cryptoBackend.maybeAcceptKeyBundle(roomId, inviter);
+            // If this fails, i.e. we haven't received this message yet, we need to wait until the to-device message arrives.
+            if (!bundleDownloaded) {
+                this.cryptoBackend.markRoomAsPendingKeyBundle(roomId, inviter);
+            }
         }
 
         // In case we were originally given an alias, check the room cache again
@@ -3443,7 +3446,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         delayOpts: SendDelayedEventRequestOpts,
         threadId: string | null,
         eventType: K,
-        content: TimelineEvents[K] & { msc4354_sticky_key: string },
+        content: TimelineEvents[K] & { msc4354_sticky_key?: string },
         txnId?: string,
     ): Promise<SendDelayedEventResponse> {
         if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
@@ -3516,7 +3519,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         stickDuration: number,
         threadId: string | null,
         eventType: K,
-        content: TimelineEvents[K] & { msc4354_sticky_key: string },
+        content: TimelineEvents[K] & { msc4354_sticky_key?: string },
         txnId?: string,
     ): Promise<ISendEventResponse> {
         if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4354_STICKY_EVENTS))) {
@@ -3537,13 +3540,17 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
     }
 
     /**
-     * Get all pending delayed events for the calling user.
+     * Get information about delayed events owned by the requesting user.
      *
      * Note: This endpoint is unstable, and can throw an `Error`.
      *   Check progress on [MSC4140](https://github.com/matrix-org/matrix-spec-proposals/pull/4140) for more details.
      */
     // eslint-disable-next-line
-    public async _unstable_getDelayedEvents(fromToken?: string): Promise<DelayedEventInfo> {
+    public async _unstable_getDelayedEvents(
+        status?: "scheduled" | "finalised",
+        delayId?: string | string[],
+        fromToken?: string,
+    ): Promise<DelayedEventInfo> {
         if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
             throw new UnsupportedDelayedEventsEndpointError(
                 "Server does not support the delayed events API",
@@ -3551,7 +3558,11 @@ 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}`,
         });
@@ -3562,8 +3573,13 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      *
      * 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.
+     *
+     * @deprecated Instead use one of:
+     * - {@link _unstable_cancelScheduledDelayedEvent}
+     * - {@link _unstable_restartScheduledDelayedEvent}
+     * - {@link _unstable_sendScheduledDelayedEvent}
      */
-    // eslint-disable-next-line
+    // eslint-disable-next-line @typescript-eslint/naming-convention
     public async _unstable_updateDelayedEvent(
         delayId: string,
         action: UpdateDelayedEventAction,
@@ -3575,17 +3591,123 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                 "updateDelayedEvent",
             );
         }
+        return await this.updateScheduledDelayedEventWithActionInBody(delayId, action, requestOptions);
+    }
 
+    /**
+     * Cancel the scheduled delivery of the delayed event matching the provided delayId.
+     *
+     * 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.
+     *
+     * @throws A M_NOT_FOUND error if no matching delayed event could be found.
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_cancelScheduledDelayedEvent(
+        delayId: string,
+        requestOptions: IRequestOpts = {},
+    ): Promise<EmptyObject> {
+        return await this.updateScheduledDelayedEvent(delayId, UpdateDelayedEventAction.Cancel, requestOptions);
+    }
+
+    /**
+     * Restart the scheduled delivery of the delayed event matching the given delayId.
+     *
+     * 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.
+     *
+     * @throws A M_NOT_FOUND error if no matching delayed event could be found.
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_restartScheduledDelayedEvent(
+        delayId: string,
+        requestOptions: IRequestOpts = {},
+    ): Promise<EmptyObject> {
+        return await this.updateScheduledDelayedEvent(delayId, UpdateDelayedEventAction.Restart, requestOptions);
+    }
+
+    /**
+     * Immediately send the delayed event matching the given delayId,
+     * instead of waiting for its scheduled delivery.
+     *
+     * 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.
+     *
+     * @throws A M_NOT_FOUND error if no matching delayed event could be found.
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_sendScheduledDelayedEvent(
+        delayId: string,
+        requestOptions: IRequestOpts = {},
+    ): Promise<EmptyObject> {
+        return await this.updateScheduledDelayedEvent(delayId, UpdateDelayedEventAction.Send, requestOptions);
+    }
+
+    private async updateScheduledDelayedEvent(
+        delayId: string,
+        action: UpdateDelayedEventAction,
+        requestOptions: IRequestOpts = {},
+    ): Promise<EmptyObject> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw new UnsupportedDelayedEventsEndpointError(
+                "Server does not support the delayed events API",
+                `${action}ScheduledDelayedEvent`,
+            );
+        }
+
+        try {
+            const path = utils.encodeUri("/delayed_events/$delayId/$action", {
+                $delayId: delayId,
+                $action: action,
+            });
+            return await this.http.request(Method.Post, path, undefined, undefined, {
+                ...requestOptions,
+                prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
+            });
+        } catch (e) {
+            if (e instanceof MatrixError && e.errcode === "M_UNRECOGNIZED") {
+                // For backwards compatibility with an older version of this endpoint
+                // which put the update action in the request body instead of the path
+                return await this.updateScheduledDelayedEventWithActionInBody(delayId, action, requestOptions);
+            } else {
+                throw e;
+            }
+        }
+    }
+
+    /**
+     * @deprecated Present for backwards compatibility with an older version of MSC4140
+     * which had a single, authenticated endpoint for updating a delayed event, instead
+     * of one unauthenticated endpoint per update action.
+     */
+    private async updateScheduledDelayedEventWithActionInBody(
+        delayId: string,
+        action: UpdateDelayedEventAction,
+        requestOptions: IRequestOpts = {},
+    ): Promise<EmptyObject> {
         const path = utils.encodeUri("/delayed_events/$delayId", {
             $delayId: delayId,
         });
         const data = {
             action,
         };
-        return await this.http.authedRequest(Method.Post, path, undefined, data, {
-            ...requestOptions,
-            prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
-        });
+        try {
+            return await this.http.request(Method.Post, path, undefined, data, {
+                ...requestOptions,
+                prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
+            });
+        } catch (e) {
+            if (e instanceof MatrixError && e.errcode === "M_MISSING_TOKEN") {
+                // For backwards compatibility with an older version of this endpoint
+                // which required authentication
+                return await this.http.authedRequest(Method.Post, path, undefined, data, {
+                    ...requestOptions,
+                    prefix: `${ClientPrefix.Unstable}/${UNSTABLE_MSC4140_DELAYED_EVENTS}`,
+                });
+            } else {
+                throw e;
+            }
+        }
     }
 
     /**
@@ -4328,6 +4450,46 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         return eventMapperFor(this, options || {});
     }
 
+    /**
+     * Calls the `/context` API for the given room ID & event ID.
+     * Returns the response, with `event` asserted and all optional arrays defaulted to an empty array.
+     * @param roomId - the room ID to request a context for
+     * @param eventId - the event ID to request a context for
+     * @throws if `event` in the response is missing
+     * @private
+     */
+    private async getEventContext(
+        roomId: string,
+        eventId: string,
+    ): Promise<IContextResponse & Omit<Required<IContextResponse>, "start" | "end">> {
+        const path = utils.encodeUri("/rooms/$roomId/context/$eventId", {
+            $roomId: roomId,
+            $eventId: eventId,
+        });
+
+        const params: Record<string, string | string[]> = {
+            limit: "0",
+        };
+        if (this.clientOpts?.lazyLoadMembers) {
+            params.filter = JSON.stringify(Filter.LAZY_LOADING_MESSAGES_FILTER);
+        }
+
+        // TODO: we should implement a backoff (as per scrollback()) to deal more nicely with HTTP errors.
+        const res = await this.http.authedRequest<IContextResponse>(Method.Get, path, params);
+        if (res.event) {
+            return {
+                start: res.start,
+                end: res.end,
+                event: res.event,
+                events_after: res.events_after ?? [],
+                events_before: res.events_before ?? [],
+                state: res.state ?? [],
+            };
+        }
+
+        throw new Error("'event' not in '/context' result - homeserver too old?");
+    }
+
     /**
      * Get an EventTimeline for the given event
      *
@@ -4342,7 +4504,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Promise which resolves:
      *    {@link EventTimeline} including the given event
      */
-    public async getEventTimeline(timelineSet: EventTimelineSet, eventId: string): Promise<Optional<EventTimeline>> {
+    public async getEventTimeline(timelineSet: EventTimelineSet, eventId: string): Promise<EventTimeline | null> {
         // don't allow any timeline support unless it's been enabled.
         if (!this.timelineSupport) {
             throw new Error(
@@ -4360,24 +4522,10 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         }
 
         if (timelineSet.thread && this.supportsThreads()) {
-            return this.getThreadTimeline(timelineSet, eventId);
+            return (await this.getThreadTimeline(timelineSet, eventId)) ?? null;
         }
 
-        const path = utils.encodeUri("/rooms/$roomId/context/$eventId", {
-            $roomId: timelineSet.room.roomId,
-            $eventId: eventId,
-        });
-
-        let params: Record<string, string | string[]> | undefined = undefined;
-        if (this.clientOpts?.lazyLoadMembers) {
-            params = { filter: JSON.stringify(Filter.LAZY_LOADING_MESSAGES_FILTER) };
-        }
-
-        // TODO: we should implement a backoff (as per scrollback()) to deal more nicely with HTTP errors.
-        const res = await this.http.authedRequest<IContextResponse>(Method.Get, path, params);
-        if (!res.event) {
-            throw new Error("'event' not in '/context' result - homeserver too old?");
-        }
+        const res = await this.getEventContext(timelineSet.room.roomId, eventId);
 
         // by the time the request completes, the event might have ended up in the timeline.
         if (timelineSet.getTimelineForEvent(eventId)) {
@@ -4388,7 +4536,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         const event = mapper(res.event);
         if (event.isRelation(THREAD_RELATION_TYPE.name)) {
             this.logger.warn("Tried loading a regular timeline at the position of a thread event");
-            return undefined;
+            return null;
         }
         const events = [
             // Order events from most recent to oldest (reverse-chronological).
@@ -4406,7 +4554,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
         } else {
             timeline = timelineSet.addTimeline();
             timeline.initialiseState(res.state.map(mapper));
-            timeline.getState(EventTimeline.FORWARDS)!.paginationToken = res.end;
+            timeline.getState(EventTimeline.FORWARDS)!.paginationToken = res.end ?? null;
         }
 
         const [timelineEvents, threadedEvents, unknownRelations] = timelineSet.room.partitionThreadedEvents(events);
@@ -4439,20 +4587,8 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             throw new Error("could not get thread timeline: not a thread timeline");
         }
 
-        const path = utils.encodeUri("/rooms/$roomId/context/$eventId", {
-            $roomId: timelineSet.room.roomId,
-            $eventId: eventId,
-        });
+        const res = await this.getEventContext(timelineSet.room.roomId, eventId);
 
-        const params: Record<string, string | string[]> = {
-            limit: "0",
-        };
-        if (this.clientOpts?.lazyLoadMembers) {
-            params.filter = JSON.stringify(Filter.LAZY_LOADING_MESSAGES_FILTER);
-        }
-
-        // TODO: we should implement a backoff (as per scrollback()) to deal more nicely with HTTP errors.
-        const res = await this.http.authedRequest<IContextResponse>(Method.Get, path, params);
         const mapper = this.getEventMapper();
         const event = mapper(res.event);
 
@@ -4532,7 +4668,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     { dir: Direction.Backward, from: res.start, recurse: recurse || undefined },
                 );
                 const eventsNewer: IEvent[] = [];
-                let nextBatch: Optional<string> = res.end;
+                let nextBatch = res.end;
                 while (nextBatch) {
                     const resNewer: IRelationsResponse = await this.fetchRelations(
                         timelineSet.room.roomId,
@@ -4541,7 +4677,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                         null,
                         { dir: Direction.Forward, from: nextBatch, recurse: recurse || undefined },
                     );
-                    nextBatch = resNewer.next_batch ?? null;
+                    nextBatch = resNewer.next_batch;
                     eventsNewer.push(...resNewer.chunk);
                 }
                 const events = [
@@ -4585,7 +4721,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * @returns Promise which resolves:
      *    {@link EventTimeline} timeline with the latest events in the room
      */
-    public async getLatestTimeline(timelineSet: EventTimelineSet): Promise<Optional<EventTimeline>> {
+    public async getLatestTimeline(timelineSet: EventTimelineSet): Promise<EventTimeline | null> {
         // don't allow any timeline support unless it's been enabled.
         if (!this.timelineSupport) {
             throw new Error(
@@ -6797,7 +6933,7 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             return;
         }
 
-        // Check if the event is excluded under MSC3414
+        // Check if the event is excluded under MSC4362
         if (
             [
                 "m.room.create",

src/common-crypto/CryptoBackend.ts

@@ -90,8 +90,20 @@ export interface CryptoBackend extends SyncCryptoCallbacks, CryptoApi {
      *
      * @param inviter - The user who invited us to the room and is expected to have
      *   sent the room key bundle.
+     *
+     * @returns `true` if the key bundle was successfuly downloaded and imported.
      */
-    maybeAcceptKeyBundle(roomId: string, inviter: string): Promise<void>;
+    maybeAcceptKeyBundle(roomId: string, inviter: string): Promise<boolean>;
+
+    /**
+     * Mark a room as pending a key bundle under MSC4268. The backend will listen for room key bundle messages, and if
+     * it sees one matching the room specified, it will automatically import it as long as the message author's ID matches
+     * the inviter's ID.
+     *
+     * @param roomId - The room we were invited to, for which we did not receive a key bundle before accepting the invite.
+     * @param inviterId - The user who invited us to the room and is expected to send the room key bundle.
+     */
+    markRoomAsPendingKeyBundle(roomId: string, inviterId: string): void;
 }
 
 /** The methods which crypto implementations should expose to the Sync api

src/crypto-api/index.ts

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

src/embedded.ts

@@ -37,7 +37,7 @@ import {
     type ISendEventResponse,
     type SendDelayedEventRequestOpts,
     type SendDelayedEventResponse,
-    type UpdateDelayedEventAction,
+    UpdateDelayedEventAction,
 } from "./@types/requests.ts";
 import { EventType, type StateEvents } from "./@types/event.ts";
 import { logger } from "./logger.ts";
@@ -459,8 +459,12 @@ export class RoomWidgetClient extends MatrixClient {
 
     /**
      * @experimental This currently relies on an unstable MSC (MSC4140).
+     * @deprecated Instead use one of:
+     * - {@link _unstable_cancelScheduledDelayedEvent}
+     * - {@link _unstable_restartScheduledDelayedEvent}
+     * - {@link _unstable_sendScheduledDelayedEvent}
      */
-    // eslint-disable-next-line
+    // eslint-disable-next-line @typescript-eslint/naming-convention
     public async _unstable_updateDelayedEvent(delayId: string, action: UpdateDelayedEventAction): Promise<EmptyObject> {
         if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
             throw new UnsupportedDelayedEventsEndpointError(
@@ -469,7 +473,67 @@ export class RoomWidgetClient extends MatrixClient {
             );
         }
 
-        await this.widgetApi.updateDelayedEvent(delayId, action).catch(timeoutToConnectionError);
+        let updateDelayedEvent: (delayId: string) => Promise<unknown>;
+        switch (action) {
+            case UpdateDelayedEventAction.Cancel:
+                updateDelayedEvent = this.widgetApi.cancelScheduledDelayedEvent;
+                break;
+            case UpdateDelayedEventAction.Restart:
+                updateDelayedEvent = this.widgetApi.cancelScheduledDelayedEvent;
+                break;
+            case UpdateDelayedEventAction.Send:
+                updateDelayedEvent = this.widgetApi.sendScheduledDelayedEvent;
+                break;
+        }
+        await updateDelayedEvent.call(this.widgetApi, delayId).catch(timeoutToConnectionError);
+        return {};
+    }
+
+    /**
+     * @experimental This currently relies on an unstable MSC (MSC4140).
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_cancelScheduledDelayedEvent(delayId: string): Promise<EmptyObject> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw new UnsupportedDelayedEventsEndpointError(
+                "Server does not support the delayed events API",
+                "cancelScheduledDelayedEvent",
+            );
+        }
+
+        await this.widgetApi.cancelScheduledDelayedEvent(delayId).catch(timeoutToConnectionError);
+        return {};
+    }
+
+    /**
+     * @experimental This currently relies on an unstable MSC (MSC4140).
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_restartScheduledDelayedEvent(delayId: string): Promise<EmptyObject> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw new UnsupportedDelayedEventsEndpointError(
+                "Server does not support the delayed events API",
+                "restartScheduledDelayedEvent",
+            );
+        }
+
+        await this.widgetApi.restartScheduledDelayedEvent(delayId).catch(timeoutToConnectionError);
+        return {};
+    }
+
+    /**
+     * @experimental This currently relies on an unstable MSC (MSC4140).
+     */
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    public async _unstable_sendScheduledDelayedEvent(delayId: string): Promise<EmptyObject> {
+        if (!(await this.doesServerSupportUnstableFeature(UNSTABLE_MSC4140_DELAYED_EVENTS))) {
+            throw new UnsupportedDelayedEventsEndpointError(
+                "Server does not support the delayed events API",
+                "sendScheduledDelayedEvent",
+            );
+        }
+
+        await this.widgetApi.sendScheduledDelayedEvent(delayId).catch(timeoutToConnectionError);
         return {};
     }
 

src/errors.ts

@@ -59,7 +59,14 @@ export class ClientStoppedError extends Error {
 export class UnsupportedDelayedEventsEndpointError extends Error {
     public constructor(
         message: string,
-        public clientEndpoint: "sendDelayedEvent" | "updateDelayedEvent" | "sendDelayedStateEvent" | "getDelayedEvents",
+        public clientEndpoint:
+            | "sendDelayedEvent"
+            | "updateDelayedEvent"
+            | "cancelScheduledDelayedEvent"
+            | "restartScheduledDelayedEvent"
+            | "sendScheduledDelayedEvent"
+            | "sendDelayedStateEvent"
+            | "getDelayedEvents",
     ) {
         super(message);
         this.name = "UnsupportedDelayedEventsEndpointError";

src/extensible_events_v1/MessageEvent.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type Optional } from "matrix-events-sdk";
-
 import { ExtensibleEvent } from "./ExtensibleEvent.ts";
 import {
     type ExtensibleEventType,
@@ -46,7 +44,7 @@ export class MessageEvent extends ExtensibleEvent<ExtensibleAnyMessageEventConte
     /**
      * The default HTML for the event, if provided.
      */
-    public readonly html: Optional<string>;
+    public readonly html?: string;
 
     /**
      * All the different renderings of the message. Note that this is the same
@@ -82,7 +80,7 @@ export class MessageEvent extends ExtensibleEvent<ExtensibleAnyMessageEventConte
             this.renderings = mmessage;
         } else if (isOptionalAString(mtext)) {
             this.text = mtext;
-            this.html = mhtml;
+            this.html = mhtml ?? undefined;
             this.renderings = [{ body: mtext, mimetype: "text/plain" }];
             if (this.html) {
                 this.renderings.push({ body: this.html, mimetype: "text/html" });

src/http-api/fetch.ts

@@ -279,6 +279,13 @@ export class FetchHttpApi<O extends IHttpOpts> {
 
         const { signal, cleanup } = anySignal(signals);
 
+        // Set cache mode based on presence of Authorization header.
+        // Browsers/proxies do not cache responses to requests with Authorization headers.
+        // So specifying "no-cache" is redundant, and actually prevents caching
+        // of preflight requests in CORS scenarios. As such, we only set "no-cache"
+        // when there is no Authorization header.
+        const cacheMode = "Authorization" in headers ? undefined : "no-cache";
+
         let res: Response;
         const start = Date.now();
         try {
@@ -291,7 +298,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
                 redirect: "follow",
                 referrer: "",
                 referrerPolicy: "no-referrer",
-                cache: "no-cache",
+                cache: cacheMode,
                 credentials: "omit", // we send credentials via headers
                 keepalive: keepAlive,
                 priority: opts.priority,

src/matrixrtc/CallMembership.ts

@@ -195,6 +195,10 @@ export type SessionMembershipData = {
      * something else.
      */
     "m.call.intent"?: RTCCallIntent;
+    /**
+     * The sticky key in case of a sticky event. This string encodes the application + device_id indicating the used slot + device.
+     */
+    "msc4354_sticky_key"?: string;
 };
 
 const checkSessionsMembershipData = (data: IContent, errors: string[]): data is SessionMembershipData => {

src/matrixrtc/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/MatrixRTCSession.ts

@@ -24,7 +24,7 @@ import { KnownMembership } from "../@types/membership.ts";
 import { type ISendEventResponse } from "../@types/requests.ts";
 import { CallMembership } from "./CallMembership.ts";
 import { RoomStateEvent } from "../models/room-state.ts";
-import { MembershipManager } from "./MembershipManager.ts";
+import { MembershipManager, StickyEventMembershipManager } from "./MembershipManager.ts";
 import { EncryptionManager, type IEncryptionManager } from "./EncryptionManager.ts";
 import { deepCompare, logDurationSync } from "../utils.ts";
 import type {
@@ -36,20 +36,17 @@ import type {
     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
@@ -123,14 +120,6 @@ export function slotDescriptionToId(slotDescription: SlotDescription): string {
 // - we use a `Ms` postfix if the option is a duration to avoid using words like:
 //   `time`, `duration`, `delay`, `timeout`... that might be mistaken/confused with technical terms.
 export interface MembershipConfig {
-    /**
-     * Use the new Manager.
-     *
-     * Default: `false`.
-     * @deprecated does nothing anymore we always default to the new membership manager.
-     */
-    useNewMembershipManager?: boolean;
-
     /**
      * The timeout (in milliseconds) after we joined the call, that our membership should expire
      * unless we have explicitly updated it.
@@ -189,10 +178,18 @@ export interface MembershipConfig {
      * In the presence of network packet loss (hurting TCP connections), the custom delayedEventRestartLocalTimeoutMs
      * helps by keeping more delayed event reset candidates in flight,
      * improving the chances of a successful reset. (its is equivalent to the js-sdk `localTimeout` configuration,
-     * but only applies to calls to the `_unstable_updateDelayedEvent` endpoint with a body of `{action:"restart"}`.)
+     * but only applies to calls to the `_unstable_restartScheduledDelayedEvent` endpoint
+     * or the `_unstable_updateDelayedEvent` endpoint with a body of `{action:"restart"}`.)
      */
     delayedLeaveEventRestartLocalTimeoutMs?: number;
-    useRtcMemberFormat?: boolean;
+
+    /**
+     * Send membership using sticky events rather than state events.
+     * This also make the client use the new m.rtc.member MSC4354 event format. (instead of m.call.member)
+     *
+     * **WARNING**: This is an unstable feature and not all clients will support it.
+     */
+    unstableSendStickyEvents?: boolean;
 }
 
 export interface EncryptionConfig {
@@ -238,13 +235,26 @@ 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;
@@ -307,7 +317,7 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * @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.sessionMembershipsForSlot(room, {
             id: "",
@@ -319,7 +329,7 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * @deprecated use `MatrixRTCSession.slotMembershipsForRoom` instead.
      */
     public static sessionMembershipsForRoom(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState">,
+        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState" | "_unstable_getStickyEvents">,
         sessionDescription: SlotDescription,
     ): CallMembership[] {
         return this.sessionMembershipsForSlot(room, sessionDescription);
@@ -328,30 +338,58 @@ export class MatrixRTCSession extends TypedEventEmitter<
     /**
      * Returns all the call memberships for a room that match the provided `sessionDescription`,
      * oldest first.
+     *
+     * By default, this will return *both* sticky and member state events.
      */
     public static sessionMembershipsForSlot(
-        room: Pick<Room, "getLiveTimeline" | "roomId" | "hasMembershipState">,
+        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) {
@@ -411,8 +449,16 @@ export class MatrixRTCSession extends TypedEventEmitter<
      *
      * @deprecated Use `MatrixRTCSession.sessionForSlot` with sessionDescription `{ id: "", application: "m.call" }` instead.
      */
-    public static roomSessionForRoom(client: MatrixClient, room: Room): MatrixRTCSession {
-        const callMemberships = MatrixRTCSession.sessionMembershipsForSlot(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" });
     }
 
@@ -428,9 +474,13 @@ export class MatrixRTCSession extends TypedEventEmitter<
      * This returned session can be used to find out if there are active sessions
      * for the requested room and `slotDescription`.
      */
-    public static sessionForSlot(client: MatrixClient, room: Room, slotDescription: SlotDescription): MatrixRTCSession {
-        const callMemberships = MatrixRTCSession.sessionMembershipsForSlot(room, slotDescription);
-
+    public static sessionForSlot(
+        client: MatrixClient,
+        room: Room,
+        slotDescription: SlotDescription,
+        opts?: SessionMembershipsForRoomOpts,
+    ): MatrixRTCSession {
+        const callMemberships = MatrixRTCSession.sessionMembershipsForSlot(room, slotDescription, opts);
         return new MatrixRTCSession(client, room, callMemberships, slotDescription);
     }
 
@@ -461,10 +511,15 @@ export class MatrixRTCSession extends TypedEventEmitter<
             MatrixClient,
             | "getUserId"
             | "getDeviceId"
+            | "sendEvent"
             | "sendStateEvent"
             | "_unstable_sendDelayedStateEvent"
             | "_unstable_updateDelayedEvent"
-            | "sendEvent"
+            | "_unstable_cancelScheduledDelayedEvent"
+            | "_unstable_restartScheduledDelayedEvent"
+            | "_unstable_sendScheduledDelayedEvent"
+            | "_unstable_sendStickyEvent"
+            | "_unstable_sendStickyDelayedEvent"
             | "cancelPendingEvent"
             | "encryptAndSendToDevice"
             | "off"
@@ -488,9 +543,10 @@ export class MatrixRTCSession extends TypedEventEmitter<
         const roomState = this.roomSubset.getLiveTimeline().getState(EventTimeline.FORWARDS);
         // TODO: double check if this is actually needed. Should be covered by refreshRoom in MatrixRTCSessionManager
         roomState?.on(RoomStateEvent.Members, this.onRoomMemberUpdate);
+        this.roomSubset.on(RoomStickyEventsEvent.Update, this.onStickyEventUpdate);
+
         this.setExpiryTimer();
     }
-
     /*
      * Returns true if we intend to be participating in the MatrixRTC session.
      * This is determined by checking if the relativeExpiry has been set.
@@ -510,10 +566,12 @@ 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);
 
     /**
@@ -540,14 +598,15 @@ export class MatrixRTCSession extends TypedEventEmitter<
             return;
         } else {
             // Create MembershipManager and pass the RTCSession logger (with room id info)
-
-            this.membershipManager = new MembershipManager(
-                joinConfig,
-                this.roomSubset,
-                this.client,
-                this.slotDescription,
-                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,
@@ -560,13 +619,7 @@ 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()!,
@@ -786,10 +839,27 @@ 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.
      */
@@ -839,6 +909,8 @@ export class MatrixRTCSession extends TypedEventEmitter<
             // If anyone else joins the session it is no longer our responsibility to send the notification.
             // (If we were the joiner we already did sent the notification in the block above.)
             if (this.memberships.length > 0) this.pendingNotificationToSend = undefined;
+        } else {
+            this.logger.debug(`No membership changes detected for room ${this.roomSubset.roomId}`);
         }
         // This also needs to be done if `changed` = false
         // A member might have updated their fingerprint (created_ts)

src/matrixrtc/MatrixRTCSessionManager.ts

@@ -18,7 +18,7 @@ import { type Logger } from "../logger.ts";
 import { type MatrixClient, ClientEvent } from "../client.ts";
 import { TypedEventEmitter } from "../models/typed-event-emitter.ts";
 import { type Room } from "../models/room.ts";
-import { type RoomState, RoomStateEvent } from "../models/room-state.ts";
+import { RoomStateEvent } from "../models/room-state.ts";
 import { type MatrixEvent } from "../models/event.ts";
 import { MatrixRTCSession, type SlotDescription } from "./MatrixRTCSession.ts";
 import { EventType } from "../@types/event.ts";
@@ -73,6 +73,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         }
 
         this.client.on(ClientEvent.Room, this.onRoom);
+        this.client.on(ClientEvent.Event, this.onEvent);
         this.client.on(RoomStateEvent.Events, this.onRoomState);
     }
 
@@ -83,6 +84,7 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         this.roomSessions.clear();
 
         this.client.off(ClientEvent.Room, this.onRoom);
+        this.client.off(ClientEvent.Event, this.onEvent);
         this.client.off(RoomStateEvent.Events, this.onRoomState);
     }
 
@@ -113,16 +115,28 @@ export class MatrixRTCSessionManager extends TypedEventEmitter<MatrixRTCSessionM
         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

@@ -16,7 +16,8 @@ limitations under the License.
 import { AbortError } from "p-retry";
 
 import { EventType, RelationType } from "../@types/event.ts";
-import { UpdateDelayedEventAction } from "../@types/requests.ts";
+import { type ISendEventResponse, type SendDelayedEventResponse } 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";
@@ -84,6 +85,12 @@ 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
@@ -144,6 +151,30 @@ 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"
+    | "_unstable_cancelScheduledDelayedEvent"
+    | "_unstable_restartScheduledDelayedEvent"
+    | "_unstable_sendScheduledDelayedEvent"
+>;
+
 /**
  * This class is responsible for sending all events relating to the own membership of a matrixRTC call.
  * It has the following tasks:
@@ -162,8 +193,8 @@ export class MembershipManager
     implements IMembershipManager
 {
     private activated = false;
-    private logger: Logger;
-    private callIntent: RTCCallIntent | undefined;
+    private readonly logger: Logger;
+    protected callIntent: RTCCallIntent | undefined;
 
     public isActivated(): boolean {
         return this.activated;
@@ -295,16 +326,9 @@ export class MembershipManager
      * @param client
      */
     public constructor(
-        private joinConfig: (SessionConfig & MembershipConfig) | undefined,
-        private room: Pick<Room, "getLiveTimeline" | "roomId" | "getVersion">,
-        private client: Pick<
-            MatrixClient,
-            | "getUserId"
-            | "getDeviceId"
-            | "sendStateEvent"
-            | "_unstable_sendDelayedStateEvent"
-            | "_unstable_updateDelayedEvent"
-        >,
+        private readonly joinConfig: (SessionConfig & MembershipConfig) | undefined,
+        protected readonly room: Pick<Room, "roomId" | "getVersion">,
+        protected readonly client: MembershipManagerClient,
         public readonly slotDescription: SlotDescription,
         parentLogger?: Logger,
     ) {
@@ -361,11 +385,11 @@ export class MembershipManager
         };
     }
     // Membership Event static parameters:
-    private deviceId: string;
-    private memberId: string;
+    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[];
-    private rtcTransport?: Transport;
 
     // Config:
     private delayedLeaveEventDelayMsOverride?: number;
@@ -380,9 +404,13 @@ 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 {
@@ -394,13 +422,10 @@ export class MembershipManager
     private get maximumNetworkErrorRetryCount(): number {
         return this.joinConfig?.maximumNetworkErrorRetryCount ?? 10;
     }
-
     private get delayedLeaveEventRestartLocalTimeoutMs(): number {
         return this.joinConfig?.delayedLeaveEventRestartLocalTimeoutMs ?? 2000;
     }
-    private get useRtcMemberFormat(): boolean {
-        return this.joinConfig?.useRtcMemberFormat ?? false;
-    }
+
     // LOOP HANDLER:
     private async membershipLoopHandler(type: MembershipActionType): Promise<ActionUpdate> {
         switch (type) {
@@ -455,22 +480,23 @@ 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,
-                },
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                {}, // leave event
-                this.memberId,
-            )
+        return await this.clientSendDelayedDisconnectMembership()
             .then((response) => {
                 this.state.expectedServerDelayLeaveTs = Date.now() + this.delayedLeaveEventDelayMs;
                 this.setAndEmitProbablyLeft(false);
@@ -494,7 +520,7 @@ 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) {
@@ -521,7 +547,7 @@ export class MembershipManager
     private async cancelKnownDelayIdBeforeSendDelayedEvent(delayId: string): Promise<ActionUpdate> {
         // Remove all running updates and restarts
         return await this.client
-            ._unstable_updateDelayedEvent(delayId, UpdateDelayedEventAction.Cancel)
+            ._unstable_cancelScheduledDelayedEvent(delayId)
             .then(() => {
                 this.state.delayId = undefined;
                 this.resetRateLimitCounter(MembershipActionType.SendDelayedEvent);
@@ -529,7 +555,7 @@ export class MembershipManager
             })
             .catch((e) => {
                 const repeatActionType = MembershipActionType.SendDelayedEvent;
-                const update = this.actionUpdateFromErrors(e, repeatActionType, "updateDelayedEvent");
+                const update = this.actionUpdateFromErrors(e, repeatActionType, "cancelScheduledDelayedEvent");
                 if (update) return update;
 
                 if (this.isNotFoundError(e)) {
@@ -583,10 +609,7 @@ export class MembershipManager
 
         // The obvious choice here would be to use the `IRequestOpts` to set the timeout. Since this call might be forwarded
         // to the widget driver this information would get lost. That is why we mimic the AbortError using the race.
-        return await Promise.race([
-            this.client._unstable_updateDelayedEvent(delayId, UpdateDelayedEventAction.Restart),
-            abortPromise,
-        ])
+        return await Promise.race([this.client._unstable_restartScheduledDelayedEvent(delayId), abortPromise])
             .then(() => {
                 // Whenever we successfully restart the delayed event we update the `state.expectedServerDelayLeaveTs`
                 // which stores the predicted timestamp at which the server will send the delayed leave event if there wont be any further
@@ -614,7 +637,7 @@ export class MembershipManager
                 if (this.isUnsupportedDelayedEndpoint(e)) return {};
 
                 // TODO this also needs a test: get rate limit while checking id delayed event is scheduled
-                const update = this.actionUpdateFromErrors(e, repeatActionType, "updateDelayedEvent");
+                const update = this.actionUpdateFromErrors(e, repeatActionType, "restartScheduledDelayedEvent");
                 if (update) return update;
 
                 // In other error cases we have no idea what is happening
@@ -624,7 +647,7 @@ export class MembershipManager
 
     private async sendScheduledDelayedLeaveEventOrFallbackToSendLeaveEvent(delayId: string): Promise<ActionUpdate> {
         return await this.client
-            ._unstable_updateDelayedEvent(delayId, UpdateDelayedEventAction.Send)
+            ._unstable_sendScheduledDelayedEvent(delayId)
             .then(() => {
                 this.state.hasMemberStateEvent = false;
                 this.resetRateLimitCounter(MembershipActionType.SendScheduledDelayedLeaveEvent);
@@ -638,7 +661,7 @@ export class MembershipManager
                     this.state.delayId = undefined;
                     return createInsertActionUpdate(repeatActionType);
                 }
-                const update = this.actionUpdateFromErrors(e, repeatActionType, "updateDelayedEvent");
+                const update = this.actionUpdateFromErrors(e, repeatActionType, "sendScheduledDelayedEvent");
                 if (update) return update;
 
                 // On any other error we fall back to SendLeaveEvent (this includes hard errors from rate limiting)
@@ -650,14 +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,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                this.makeMyMembership(this.membershipEventExpiryMs),
-                this.memberId,
-            )
+        return await this.clientSendMembership(this.makeMyMembership(this.membershipEventExpiryMs))
             .then(() => {
                 this.setAndEmitProbablyLeft(false);
                 this.state.startTime = Date.now();
@@ -697,13 +725,9 @@ export class MembershipManager
 
     private async updateExpiryOnJoinedEvent(): Promise<ActionUpdate> {
         const nextExpireUpdateIteration = this.state.expireUpdateIterations + 1;
-        return await this.client
-            .sendStateEvent(
-                this.room.roomId,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                this.makeMyMembership(this.membershipEventExpiryMs * nextExpireUpdateIteration),
-                this.memberId,
-            )
+        return await this.clientSendMembership(
+            this.makeMyMembership(this.membershipEventExpiryMs * nextExpireUpdateIteration),
+        )
             .then(() => {
                 // Success, we reset retries and schedule update.
                 this.resetRateLimitCounter(MembershipActionType.UpdateExpiry);
@@ -725,13 +749,7 @@ export class MembershipManager
             });
     }
     private async sendFallbackLeaveEvent(): Promise<ActionUpdate> {
-        return await this.client
-            .sendStateEvent(
-                this.room.roomId,
-                this.useRtcMemberFormat ? EventType.RTCMembership : EventType.GroupCallMemberPrefix,
-                {},
-                this.memberId,
-            )
+        return await this.clientSendMembership({})
             .then(() => {
                 this.resetRateLimitCounter(MembershipActionType.SendLeaveEvent);
                 this.state.hasMemberStateEvent = false;
@@ -757,45 +775,29 @@ export class MembershipManager
     /**
      * Constructs our own membership
      */
-    private makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
+    protected makeMyMembership(expires: number): SessionMembershipData | RtcMembershipData {
         const ownMembership = this.ownMembership;
-        if (this.useRtcMemberFormat) {
-            const relationObject = ownMembership?.eventId
-                ? { "m.relation": { rel_type: RelationType.Reference, event_id: ownMembership?.eventId } }
-                : {};
-            return {
-                application: {
-                    type: this.slotDescription.application,
-                    ...(this.callIntent ? { "m.call.intent": this.callIntent } : {}),
-                },
-                slot_id: slotDescriptionToId(this.slotDescription),
-                rtc_transports: this.rtcTransport ? [this.rtcTransport] : [],
-                member: { device_id: this.deviceId, user_id: this.client.getUserId()!, id: this.memberId },
-                versions: [],
-                ...relationObject,
-            };
-        } else {
-            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 {
-                "application": this.slotDescription.application,
-                "call_id": this.slotDescription.id,
-                "scope": "m.room",
-                "device_id": this.deviceId,
-                expires,
-                "m.call.intent": this.callIntent,
-                ...focusObjects,
-                ...(ownMembership !== undefined ? { created_ts: ownMembership.createdTs() } : undefined),
-            };
-        }
+
+        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 {
+            "application": this.slotDescription.application,
+            "call_id": this.slotDescription.id,
+            "scope": "m.room",
+            "device_id": this.deviceId,
+            expires,
+            "m.call.intent": this.callIntent,
+            ...focusObjects,
+            ...(ownMembership !== undefined ? { created_ts: ownMembership.createdTs() } : undefined),
+        };
     }
 
     // Error checks and handlers
@@ -830,7 +832,7 @@ export class MembershipManager
         return false;
     }
 
-    private actionUpdateFromErrors(
+    protected actionUpdateFromErrors(
         error: unknown,
         type: MembershipActionType,
         method: string,
@@ -878,7 +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 });
     }
 
     /**
@@ -1022,14 +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/types.ts

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

src/models/event.ts

@@ -19,7 +19,7 @@ limitations under the License.
  * the public classes.
  */
 
-import { type ExtensibleEvent, ExtensibleEvents, type Optional } from "matrix-events-sdk";
+import { type ExtensibleEvent, ExtensibleEvents } from "matrix-events-sdk";
 
 import type { IEventDecryptionResult } from "../@types/crypto.ts";
 import { logger } from "../logger.ts";
@@ -270,7 +270,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
     // addition to a falsy cached event value. We check the flag later on in
     // a public getter to decide if the cache is valid.
     private _hasCachedExtEv = false;
-    private _cachedExtEv: Optional<ExtensibleEvent> = undefined;
+    private _cachedExtEv?: ExtensibleEvent = undefined;
 
     /** If we failed to decrypt this event, the reason for the failure. Otherwise, `null`. */
     private _decryptionFailureReason: DecryptionFailureCode | null = null;
@@ -481,9 +481,9 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
      *
      * @deprecated Use stable functions where possible.
      */
-    public get unstableExtensibleEvent(): Optional<ExtensibleEvent> {
+    public get unstableExtensibleEvent(): ExtensibleEvent | undefined {
         if (!this._hasCachedExtEv) {
-            this._cachedExtEv = ExtensibleEvents.parse(this.getEffectiveEvent());
+            this._cachedExtEv = ExtensibleEvents.parse(this.getEffectiveEvent()) ?? undefined;
         }
         return this._cachedExtEv;
     }
@@ -753,7 +753,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
 
     /**
      * 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
+     * string-unpacking on the state key, as per MSC4362. This will return
      * <code>undefined</code> for message events.
      * @returns The event's `state_key`.
      */
@@ -766,7 +766,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
 
     /**
      * 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
+     * MSC4362 if the state event is encrypted. This will return <code>undefined
      * </code> for message events.
      * @returns The event's `state_key`.
      */
@@ -789,7 +789,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
      * @returns The user's room membership, or `undefined` if the server does
      *   not report it.
      */
-    public getMembershipAtEvent(): Optional<Membership | string> {
+    public getMembershipAtEvent(): Membership | string | undefined {
         const unsigned = this.getUnsigned();
         return UNSIGNED_MEMBERSHIP_FIELD.findIn<Membership | string>(unsigned);
     }

src/models/room-sticky-events.ts

@@ -8,7 +8,7 @@ export enum RoomStickyEventsEvent {
     Update = "RoomStickyEvents.Update",
 }
 
-type StickyMatrixEvent = MatrixEvent & { unstableStickyExpiresAt: number };
+export type StickyMatrixEvent = MatrixEvent & { unstableStickyExpiresAt: number };
 
 export type RoomStickyEventsMap = {
     /**
@@ -24,17 +24,64 @@ export type RoomStickyEventsMap = {
     ) => void;
 };
 
+type UserId = `@${string}`;
+
+function assertIsUserId(value: unknown): asserts value is UserId {
+    if (typeof value !== "string") throw new Error("Not a string");
+    if (!value.startsWith("@")) throw new Error("Not a userId");
+}
+
 /**
  * Tracks sticky events on behalf of one room, and fires an event
  * whenever a sticky event is updated or replaced.
  */
 export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEvent, RoomStickyEventsMap> {
-    private readonly stickyEventsMap = new Map<string, Map<string, StickyMatrixEvent>>(); // (type -> stickyKey+userId) -> event
+    /**
+     * Sticky event map is a nested map of:
+     *  eventType -> `content.sticky_key sender` -> StickyMatrixEvent[]
+     *
+     * The events are ordered in latest to earliest expiry, so that the first event
+     * in the array will always be the "current" one.
+     */
+    private readonly stickyEventsMap = new Map<string, Map<string, StickyMatrixEvent[]>>();
+    /**
+     * These are sticky events that have no sticky key and therefore exist outside the tuple
+     * system above. They are just held in this Set until they expire.
+     */
     private readonly unkeyedStickyEvents = new Set<StickyMatrixEvent>();
 
     private stickyEventTimer?: ReturnType<typeof setTimeout>;
     private nextStickyEventExpiryTs: number = Number.MAX_SAFE_INTEGER;
 
+    /**
+     * Sort two sticky events by order of expiry. This assumes the sticky events have the same
+     * `type`, `sticky_key` and `sender`.
+     * @returns A positive value if event A will expire sooner, or a negative value if event B will expire sooner.
+     */
+    private static sortStickyEvent(eventA: StickyMatrixEvent, eventB: StickyMatrixEvent): number {
+        // Sticky events with the same key have to use the same expiration duration.
+        // Hence, comparing via `origin_server_ts` yields the exact same result as comparing their expiration time.
+        if (eventB.getTs() !== eventA.getTs()) {
+            return eventB.getTs() - eventA.getTs();
+        }
+
+        if ((eventB.getId() ?? "") > (eventA.getId() ?? "")) {
+            return 1;
+        }
+
+        // This should fail as we've got corruption in our sticky array.
+        throw Error("Comparing two sticky events with the same event ID is not allowed.");
+    }
+
+    /**
+     * Generate the correct key for an event to be found in the inner maps of `stickyEventsMap`.
+     * @param stickyKey The sticky key of an event.
+     * @param sender The sender of the event.
+     */
+    private static stickyMapKey(stickyKey: string, sender: UserId): string {
+        return `${stickyKey}${sender}`;
+    }
+
     /**
      * Get all sticky events that are currently active.
      * @returns An iterable set of events.
@@ -42,7 +89,11 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
     public *getStickyEvents(): Iterable<StickyMatrixEvent> {
         yield* this.unkeyedStickyEvents;
         for (const innerMap of this.stickyEventsMap.values()) {
-            yield* innerMap.values();
+            // Inner map contains a map of sender+stickykeys => all sticky events
+            for (const events of innerMap.values()) {
+                // The first sticky event is the "current" one in the sticky map.
+                yield events[0];
+            }
         }
     }
 
@@ -54,7 +105,8 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
      * @returns A matching active sticky event, or undefined.
      */
     public getKeyedStickyEvent(sender: string, type: string, stickyKey: string): StickyMatrixEvent | undefined {
-        return this.stickyEventsMap.get(type)?.get(`${stickyKey}${sender}`);
+        assertIsUserId(sender);
+        return this.stickyEventsMap.get(type)?.get(RoomStickyEventsStore.stickyMapKey(stickyKey, sender))?.[0];
     }
 
     /**
@@ -89,9 +141,8 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         }
         const sender = event.getSender();
         const type = event.getType();
-        if (!sender) {
-            throw new Error(`${event.getId()} is missing a sender`);
-        } else if (event.unstableStickyExpiresAt <= Date.now()) {
+        assertIsUserId(sender);
+        if (event.unstableStickyExpiresAt <= Date.now()) {
             logger.info("ignored sticky event with older expiration time than current time", stickyKey);
             return { added: false };
         }
@@ -102,42 +153,39 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
             throw new Error("Expected sender to start with @");
         }
 
-        let prevEvent: StickyMatrixEvent | undefined;
-        if (stickyKey !== undefined) {
-            // Why this is safe:
-            // A type may contain anything but the *sender* is tightly
-            // constrained so that a key will always end with a @<user_id>
-            // E.g. Where a malicous event type might be "rtc.member.event@foo:bar" the key becomes:
-            // "rtc.member.event.@foo:bar@bar:baz"
-            const innerMapKey = `${stickyKey}${sender}`;
-            prevEvent = this.stickyEventsMap.get(type)?.get(innerMapKey);
+        const stickyEvent = event as StickyMatrixEvent;
 
-            // sticky events are not allowed to expire sooner than their predecessor.
-            if (prevEvent && event.unstableStickyExpiresAt < prevEvent.unstableStickyExpiresAt) {
-                logger.info("ignored sticky event with older expiry time", stickyKey);
-                return { added: false };
-            } else if (
-                prevEvent &&
-                event.getTs() === prevEvent.getTs() &&
-                (event.getId() ?? "") < (prevEvent.getId() ?? "")
-            ) {
-                // This path is unlikely, as it requires both events to have the same TS.
-                logger.info("ignored sticky event due to 'id tie break rule' on sticky_key", stickyKey);
-                return { added: false };
-            }
-            if (!this.stickyEventsMap.has(type)) {
-                this.stickyEventsMap.set(type, new Map());
-            }
-            this.stickyEventsMap.get(type)!.set(innerMapKey, event as StickyMatrixEvent);
-        } else {
-            this.unkeyedStickyEvents.add(event as StickyMatrixEvent);
+        if (stickyKey === undefined) {
+            this.unkeyedStickyEvents.add(stickyEvent);
+            // Recalculate the next expiry time.
+            this.nextStickyEventExpiryTs = Math.min(event.unstableStickyExpiresAt, this.nextStickyEventExpiryTs);
+
+            this.scheduleStickyTimer();
+            return { added: true };
         }
 
+        // 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(event.unstableStickyExpiresAt, this.nextStickyEventExpiryTs);
+        this.nextStickyEventExpiryTs = Math.min(stickyEvent.unstableStickyExpiresAt, this.nextStickyEventExpiryTs);
 
         this.scheduleStickyTimer();
-        return { added: true, prevEvent };
+        return {
+            added: currentEventSet[0] === stickyEvent,
+            prevEvent: currentEventSet?.[1],
+        };
     }
 
     /**
@@ -193,17 +241,24 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         // We will recalculate this as we check all events.
         this.nextStickyEventExpiryTs = Number.MAX_SAFE_INTEGER;
         for (const [eventType, innerEvents] of this.stickyEventsMap.entries()) {
-            for (const [innerMapKey, event] of innerEvents) {
+            for (const [innerMapKey, [currentEvent, ...previousEvents]] of innerEvents) {
                 // we only added items with `sticky` into this map so we can assert non-null here
-                if (now >= event.unstableStickyExpiresAt) {
-                    logger.debug("Expiring sticky event", event.getId());
-                    removedEvents.push(event);
+                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,
-                        event.unstableStickyExpiresAt,
+                        currentEvent.unstableStickyExpiresAt,
                     );
                 }
             }
@@ -229,6 +284,93 @@ export class RoomStickyEventsStore extends TypedEventEmitter<RoomStickyEventsEve
         this.scheduleStickyTimer();
     };
 
+    /**
+     * Handles incoming event redactions. Checks the sticky map
+     * for any active sticky events being redacted.
+     * @param redactedEvent The MatrixEvent OR event ID of the event being redacted. MAY not be a sticky event.
+     */
+    public handleRedaction(redactedEvent: MatrixEvent | string): void {
+        // Note, we do not adjust`nextStickyEventExpiryTs` here.
+        // If this event happens to be the most recent expiring event
+        // then we may do one extra iteration of cleanExpiredStickyEvents
+        // but this saves us having to iterate over all events here to calculate
+        // the next expiry time.
+
+        // Note, as soon as we find a positive match on an event in this function
+        // we can return. There is no need to continue iterating on a positive match
+        // as an event can only appear in one map.
+
+        // Handle unkeyedStickyEvents first since it's *quick*.
+        const redactEventId = typeof redactedEvent === "string" ? redactedEvent : redactedEvent.getId();
+        for (const event of this.unkeyedStickyEvents) {
+            if (event.getId() === redactEventId) {
+                this.unkeyedStickyEvents.delete(event);
+                this.emit(RoomStickyEventsEvent.Update, [], [], [event]);
+                return;
+            }
+        }
+
+        // Faster method of finding the event since we have the event cached.
+        if (typeof redactedEvent !== "string" && !redactedEvent.isRedacted()) {
+            const stickyKey = redactedEvent.getContent().msc4354_sticky_key;
+            if (typeof stickyKey !== "string" && stickyKey !== undefined) {
+                return; // Not a sticky event.
+            }
+            const eventType = redactedEvent.getType();
+            const sender = redactedEvent.getSender();
+            assertIsUserId(sender);
+            const innerMap = this.stickyEventsMap.get(eventType);
+            if (!innerMap) {
+                return;
+            }
+            const mapKey = RoomStickyEventsStore.stickyMapKey(stickyKey, sender);
+            const [currentEvent, ...previousEvents] = innerMap.get(mapKey) ?? [];
+            if (!currentEvent) {
+                // No event current in the map so ignore.
+                return;
+            }
+            logger.debug(`Redaction for ${redactEventId} under sticky key ${stickyKey}`);
+            // Revert to previous state, taking care to skip any other redacted events.
+            const newEvents = previousEvents.filter((e) => !e.isRedacted()).sort(RoomStickyEventsStore.sortStickyEvent);
+            this.stickyEventsMap.get(eventType)?.set(mapKey, newEvents);
+            if (newEvents.length) {
+                this.emit(
+                    RoomStickyEventsEvent.Update,
+                    [],
+                    [
+                        {
+                            // This looks confusing. This emits that the newer event
+                            // has been redacted and the previous event has taken it's place.
+                            previous: currentEvent,
+                            current: newEvents[0],
+                        },
+                    ],
+                    [],
+                );
+            } else {
+                // We did not find a previous event, so just expire.
+                innerMap.delete(mapKey);
+                if (innerMap.size === 0) {
+                    this.stickyEventsMap.delete(eventType);
+                }
+                this.emit(RoomStickyEventsEvent.Update, [], [], [currentEvent]);
+            }
+            return;
+        }
+
+        // We only know the event ID of the redacted event, so we need to
+        // traverse the map to find our event.
+        for (const innerMap of this.stickyEventsMap.values()) {
+            for (const [currentEvent] of innerMap.values()) {
+                if (currentEvent.getId() !== redactEventId) {
+                    continue;
+                }
+                // Found the event.
+                return this.handleRedaction(currentEvent);
+            }
+        }
+    }
+
     /**
      * Clear all events and stop the timer from firing.
      */

src/models/room.ts

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { M_POLL_START, type Optional } from "matrix-events-sdk";
+import { M_POLL_START } from "matrix-events-sdk";
 
 import {
     DuplicateStrategy,
@@ -1196,7 +1196,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         // Get the main TimelineSet
         const timelineSet = this.getUnfilteredTimelineSet();
 
-        let newTimeline: Optional<EventTimeline>;
+        let newTimeline: EventTimeline | null = null;
         // If there isn't any event in the timeline, let's go fetch the latest
         // event and construct a timeline from it.
         //
@@ -1783,12 +1783,11 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
         allowDefault = true,
         useAuthentication: boolean = false,
     ): string | null {
-        const roomAvatarEvent = this.currentState.getStateEvents(EventType.RoomAvatar, "");
-        if (!roomAvatarEvent && !allowDefault) {
+        const mainUrl = this.getMxcAvatarUrl();
+        if (!mainUrl && !allowDefault) {
             return null;
         }
 
-        const mainUrl = roomAvatarEvent ? roomAvatarEvent.getContent().url : null;
         if (mainUrl) {
             return getHttpUriForMxc(
                 baseUrl,
@@ -1810,7 +1809,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @returns the mxc avatar url or falsy
      */
     public getMxcAvatarUrl(): string | null {
-        return this.currentState.getStateEvents(EventType.RoomAvatar, "")?.getContent()?.url || null;
+        const url = this.currentState.getStateEvents(EventType.RoomAvatar, "")?.getContent().url;
+        return url && typeof url === "string" ? url : null;
     }
 
     /**
@@ -1820,11 +1820,8 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @returns The room's canonical alias, or null if there is none
      */
     public getCanonicalAlias(): string | null {
-        const canonicalAlias = this.currentState.getStateEvents(EventType.RoomCanonicalAlias, "");
-        if (canonicalAlias) {
-            return canonicalAlias.getContent().alias || null;
-        }
-        return null;
+        const canonicalAlias = this.currentState.getStateEvents(EventType.RoomCanonicalAlias, "")?.getContent().alias;
+        return canonicalAlias && typeof canonicalAlias === "string" ? canonicalAlias : null;
     }
 
     /**
@@ -1832,9 +1829,9 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * @returns The room's alternative aliases, or an empty array
      */
     public getAltAliases(): string[] {
-        const canonicalAlias = this.currentState.getStateEvents(EventType.RoomCanonicalAlias, "");
-        if (canonicalAlias) {
-            return canonicalAlias.getContent().alt_aliases || [];
+        const altAliases = this.currentState.getStateEvents(EventType.RoomCanonicalAlias, "")?.getContent().alt_aliases;
+        if (Array.isArray(altAliases)) {
+            return altAliases.filter((alias) => typeof alias === "string");
         }
         return [];
     }
@@ -2493,7 +2490,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
     };
 
     private updateThreadRootEvent = (
-        timelineSet: Optional<EventTimelineSet>,
+        timelineSet: EventTimelineSet | undefined,
         thread: Thread,
         toStartOfTimeline: boolean,
         recreateEvent: boolean,
@@ -2633,6 +2630,14 @@ 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);
             }
@@ -3632,13 +3637,11 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      */
     private calculateRoomName(userId: string, ignoreRoomNameEvent = false): string {
         if (!ignoreRoomNameEvent) {
-            // check for an alias, if any. for now, assume first alias is the
-            // official one.
-            const mRoomName = this.currentState.getStateEvents(EventType.RoomName, "");
-            if (mRoomName?.getContent().name) {
+            const name = this.currentState.getStateEvents(EventType.RoomName, "")?.getContent().name;
+            if (name && typeof name === "string") {
                 return this.roomNameGenerator({
                     type: RoomNameType.Actual,
-                    name: mRoomName.getContent().name,
+                    name,
                 });
             }
         }

src/models/thread.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type Optional } from "matrix-events-sdk";
-
 import { type MatrixClient, PendingEventOrdering } from "../client.ts";
 import { TypedReEmitter } from "../ReEmitter.ts";
 import { RelationType } from "../@types/event.ts";
@@ -476,7 +474,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
         }
     }
 
-    public async processEvent(event: Optional<MatrixEvent>): Promise<void> {
+    public async processEvent(event: MatrixEvent | null | undefined): Promise<void> {
         if (event) {
             this.setEventMetadata(event);
             await this.fetchEditsWhereNeeded(event);
@@ -686,14 +684,14 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
         }
     }
 
-    public setEventMetadata(event: Optional<MatrixEvent>): void {
+    public setEventMetadata(event: MatrixEvent | null | undefined): void {
         if (event) {
             EventTimeline.setEventMetadata(event, this.roomState, false);
             event.setThread(this);
         }
     }
 
-    public clearEventMetadata(event: Optional<MatrixEvent>): void {
+    public clearEventMetadata(event: MatrixEvent | null | undefined): void {
         if (event) {
             event.setThread(undefined);
             delete event.event?.unsigned?.["m.relations"]?.[THREAD_RELATION_TYPE.name];
@@ -739,7 +737,7 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
      * A getter for the last event of the thread.
      * This might be a synthesized event, if so, it will not emit any events to listeners.
      */
-    public get replyToEvent(): Optional<MatrixEvent> {
+    public get replyToEvent(): MatrixEvent | null {
         return this.lastPendingEvent ?? this.lastEvent ?? this.lastReply();
     }
 

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";
@@ -128,6 +129,9 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
     /** mapping of roomId → encryptor class */
     private roomEncryptors: Record<string, RoomEncryptor> = {};
 
+    /** mapping of room ID -> inviter ID for rooms pending MSC4268 key bundles */
+    private readonly roomsPendingKeyBundles: Map<string, string> = new Map();
+
     private eventDecryptor: EventDecryptor;
     private keyClaimManager: KeyClaimManager;
     private outgoingRequestProcessor: OutgoingRequestProcessor;
@@ -163,7 +167,7 @@ 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. */
+        /** Enable support for encrypted state events under MSC4362. */
         private readonly enableEncryptedStateEvents: boolean = false,
     ) {
         super();
@@ -328,10 +332,9 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
     /**
      * Implementation of {@link CryptoBackend.maybeAcceptKeyBundle}.
      */
-    public async maybeAcceptKeyBundle(roomId: string, inviter: string): Promise<void> {
+    public async maybeAcceptKeyBundle(roomId: string, inviter: string): Promise<boolean> {
         // TODO: retry this if it gets interrupted or it fails. (https://github.com/matrix-org/matrix-rust-sdk/issues/5112)
         // TODO: do this in the background.
-        // TODO: handle the bundle message arriving after the invite (https://github.com/element-hq/element-web/issues/30740)
 
         const logger = new LogSpan(this.logger, `maybeAcceptKeyBundle(${roomId}, ${inviter})`);
 
@@ -351,7 +354,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
         );
         if (!bundleData) {
             logger.info("No key bundle found for user");
-            return;
+            return false;
         }
 
         logger.info(`Fetching key bundle ${bundleData.url}`);
@@ -390,7 +393,17 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             logger.warn(`Error receiving encrypted bundle:`, err);
             throw err;
         }
+
+        return true;
     }
+
+    /**
+     * Implementation of {@link CryptoBackend.markRoomAsPendingKeyBundle}.
+     */
+    public markRoomAsPendingKeyBundle(roomId: string, inviter: string): void {
+        this.roomsPendingKeyBundles.set(roomId, inviter);
+    }
+
     ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     //
     // CryptoApi implementation
@@ -827,6 +840,13 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
      * Implementation of {@link CryptoApi#isSecretStorageReady}
      */
     public async isSecretStorageReady(): Promise<boolean> {
+        return (await this.getSecretStorageStatus()).ready;
+    }
+
+    /**
+     * Implementation of {@link CryptoApi#getSecretStorageStatus}
+     */
+    public async getSecretStorageStatus(): Promise<SecretStorageStatus> {
         // make sure that the cross-signing keys are stored
         const secretsToCheck: SecretStorageKey[] = [
             "m.cross_signing.master",
@@ -834,13 +854,32 @@ 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;
     }
 
     /**
@@ -1676,6 +1715,37 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
                             senderVerified: encryptionInfo.isSenderVerified(),
                         },
                     });
+
+                    // If we have received a room key bundle message, and have previously marked the room
+                    // IDs it references as pending key bundles, tell the Rust SDK to try and accept it,
+                    // just in case it was received after invite.
+                    //
+                    // We don't actually need to validate the contents of the bundle message, or do
+                    // anything with its contents at all. We simply want to inform the Rust SDK we have
+                    // received a new room key bundle that we might be able to download.
+                    if (
+                        isRoomKeyBundleMessage(parsedMessage) &&
+                        this.roomsPendingKeyBundles.has(parsedMessage.content.room_id)
+                    ) {
+                        // No `await`-ing here, as this is called from inside the `/sync` loop.
+                        this.maybeAcceptKeyBundle(
+                            parsedMessage.content.room_id,
+                            this.roomsPendingKeyBundles.get(parsedMessage.content.room_id)!,
+                        ).then(
+                            (success) => {
+                                if (success) {
+                                    this.roomsPendingKeyBundles.delete(parsedMessage.content.room_id);
+                                }
+                            },
+                            (err) => {
+                                this.logger.error(
+                                    `Error attempting to download key bundle for room ${parsedMessage.content.room_id}`,
+                                );
+                                this.logger.error(err);
+                            },
+                        );
+                    }
+
                     break;
                 }
                 case RustSdkCryptoJs.ProcessedToDeviceEventType.PlainText: {
@@ -1747,7 +1817,7 @@ export class RustCrypto extends TypedEventEmitter<RustCryptoEvents, CryptoEventH
             return;
         }
 
-        if (config["io.element.msc3414.encrypt_state_events"] && this.enableEncryptedStateEvents) {
+        if (config["io.element.msc4362.encrypt_state_events"] && this.enableEncryptedStateEvents) {
             this.logger.info("crypto Enabling state event encryption...");
             settings.encryptStateEvents = true;
         }
@@ -2441,5 +2511,25 @@ function rustEncryptionInfoToJsEncryptionInfo(
     return { shieldColour, shieldReason };
 }
 
+interface RoomKeyBundleMessage {
+    type: "io.element.msc4268.room_key_bundle";
+    content: {
+        room_id: string;
+    };
+}
+
+/**
+ * Determines if the given payload is a RoomKeyBundleMessage.
+ *
+ * A RoomKeyBundleMessage is identified by having a specific message type
+ * ("io.element.msc4268.room_key_bundle") and a valid room_id in its content.
+ *
+ * @param message - The received to-device message to check.
+ * @returns True if the payload matches the RoomKeyBundleMessage structure, false otherwise.
+ */
+function isRoomKeyBundleMessage(message: IToDeviceEvent): message is IToDeviceEvent & RoomKeyBundleMessage {
+    return message.type === "io.element.msc4268.room_key_bundle" && typeof message.content.room_id === "string";
+}
+
 type CryptoEvents = (typeof CryptoEvent)[keyof typeof CryptoEvent];
 type RustCryptoEvents = Exclude<CryptoEvents, CryptoEvent.LegacyCryptoStoreMigrationProgress>;

src/sync.ts

@@ -23,8 +23,6 @@ limitations under the License.
  * for HTTP and WS at some point.
  */
 
-import { type Optional } from "matrix-events-sdk";
-
 import type { SyncCryptoCallbacks } from "./common-crypto/CryptoBackend.ts";
 import { User } from "./models/user.ts";
 import { NotificationCountType, Room, RoomEvent } from "./models/room.ts";
@@ -208,7 +206,7 @@ export class SyncApi {
     private readonly opts: IStoredClientOpts;
     private readonly syncOpts: SyncApiOptions;
 
-    private _peekRoom: Optional<Room> = null;
+    private _peekRoom: Room | null = null;
     private currentSyncRequest?: Promise<ISyncResponse>;
     private abortController?: AbortController;
     private syncState: SyncState | null = null;

src/timeline-window.ts

@@ -14,8 +14,6 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { type Optional } from "matrix-events-sdk";
-
 import { type Direction, EventTimeline } from "./models/event-timeline.ts";
 import { logger } from "./logger.ts";
 import { type MatrixClient } from "./client.ts";
@@ -105,7 +103,7 @@ export class TimelineWindow {
     public load(initialEventId?: string, initialWindowSize = 20): Promise<void> {
         // given an EventTimeline, find the event we were looking for, and initialise our
         // fields so that the event in question is in the middle of the window.
-        const initFields = (timeline: Optional<EventTimeline>): void => {
+        const initFields = (timeline: EventTimeline | null): void => {
             if (!timeline) {
                 throw new Error("No timeline given to initFields");
             }

src/utils.ts

@@ -20,7 +20,6 @@ limitations under the License.
 
 import unhomoglyph from "unhomoglyph";
 import promiseRetry from "p-retry";
-import { type Optional } from "matrix-events-sdk";
 
 import { type IEvent, type MatrixEvent } from "./models/event.ts";
 import { M_TIMESTAMP } from "./@types/location.ts";
@@ -115,7 +114,7 @@ export function decodeParams(query: string): Record<string, string | string[]> {
  * variables with. E.g. `{ "$bar": "baz" }`.
  * @returns The result of replacing all template variables e.g. '/foo/baz'.
  */
-export function encodeUri(pathTemplate: string, variables: Record<string, Optional<string>>): string {
+export function encodeUri(pathTemplate: string, variables: Record<string, string | null | undefined>): string {
     for (const key in variables) {
         if (!variables.hasOwnProperty(key)) {
             continue;

src/webrtc/mediaHandler.ts

@@ -264,8 +264,19 @@ export class MediaHandler extends TypedEventEmitter<
         }
 
         if (!canReuseStream) {
-            const constraints = this.getUserMediaContraints(shouldRequestAudio, shouldRequestVideo);
-            stream = await navigator.mediaDevices.getUserMedia(constraints);
+            let constraints: MediaStreamConstraints;
+            try {
+                // Not specifying exact for deviceId means switching devices does not always work,
+                // try with exact and fallback to ideal if it fails
+                constraints = this.getUserMediaContraints(shouldRequestAudio, shouldRequestVideo, true);
+                stream = await navigator.mediaDevices.getUserMedia(constraints);
+            } catch (e) {
+                logger.warn(
+                    `MediaHandler getUserMediaStreamInternal() error (e=${e}), retrying without exact deviceId`,
+                );
+                constraints = this.getUserMediaContraints(shouldRequestAudio, shouldRequestVideo, false);
+                stream = await navigator.mediaDevices.getUserMedia(constraints);
+            }
             logger.log(
                 `MediaHandler getUserMediaStreamInternal() calling getUserMediaStream (streamId=${
                     stream.id
@@ -435,30 +446,36 @@ export class MediaHandler extends TypedEventEmitter<
         this.emit(MediaHandlerEvent.LocalStreamsChanged);
     }
 
-    private getUserMediaContraints(audio: boolean, video: boolean): MediaStreamConstraints {
+    private getUserMediaContraints(audio: boolean, video: boolean, exactDeviceId?: boolean): MediaStreamConstraints {
         const isWebkit = !!navigator.webkitGetUserMedia;
+        const deviceIdKey = exactDeviceId ? "exact" : "ideal";
+
+        const audioConstraints: MediaTrackConstraints = {};
+        if (this.audioInput) {
+            audioConstraints.deviceId = { [deviceIdKey]: this.audioInput };
+        }
+        if (this.audioSettings) {
+            audioConstraints.autoGainControl = { ideal: this.audioSettings.autoGainControl };
+            audioConstraints.echoCancellation = { ideal: this.audioSettings.echoCancellation };
+            audioConstraints.noiseSuppression = { ideal: this.audioSettings.noiseSuppression };
+        }
+
+        const videoConstraints: MediaTrackConstraints = {
+            /* We want 640x360.  Chrome will give it only if we ask exactly,
+               FF refuses entirely if we ask exactly, so have to ask for ideal
+               instead
+               XXX: Is this still true?
+             */
+            width: isWebkit ? { exact: 640 } : { ideal: 640 },
+            height: isWebkit ? { exact: 360 } : { ideal: 360 },
+        };
+        if (this.videoInput) {
+            videoConstraints.deviceId = { [deviceIdKey]: this.videoInput };
+        }
 
         return {
-            audio: audio
-                ? {
-                      deviceId: this.audioInput ? { ideal: this.audioInput } : undefined,
-                      autoGainControl: this.audioSettings ? { ideal: this.audioSettings.autoGainControl } : undefined,
-                      echoCancellation: this.audioSettings ? { ideal: this.audioSettings.echoCancellation } : undefined,
-                      noiseSuppression: this.audioSettings ? { ideal: this.audioSettings.noiseSuppression } : undefined,
-                  }
-                : false,
-            video: video
-                ? {
-                      deviceId: this.videoInput ? { ideal: this.videoInput } : undefined,
-                      /* We want 640x360.  Chrome will give it only if we ask exactly,
-                   FF refuses entirely if we ask exactly, so have to ask for ideal
-                   instead
-                   XXX: Is this still true?
-                 */
-                      width: isWebkit ? { exact: 640 } : { ideal: 640 },
-                      height: isWebkit ? { exact: 360 } : { ideal: 360 },
-                  }
-                : false,
+            audio: audio ? audioConstraints : false,
+            video: video ? videoConstraints : false,
         };
     }