v40.0.0

v40.0.0-rc.0
Implement MSC4387: M_SAFETY error (#5107 )
2026-01-13 14:28:14 +00:00 · 2026-01-06 14:01:30 +00:00 · 2026-01-06 13:04:52 +00:00 · 2026-01-06 11:23:13 +00:00 · 2026-01-05 18:40:11 +00:00 · 2026-01-05 17:42:21 +00:00
136 changed files with 10823 additions and 4988 deletions
@@ -22,7 +22,7 @@ runs:

        - name: Upload tarball signature
          if: ${{ inputs.upload-url }}
-          uses: shogo82148/actions-upload-release-asset@610b1987249a69a79de9565777e112fb38f22436 # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
          with:
              upload_url: ${{ inputs.upload-url }}
              asset_path: ${{ env.VERSION }}.tar.gz.asc
@@ -29,13 +29,13 @@ runs:

        - name: Upload asset signatures
          if: inputs.gpg-fingerprint
-          uses: shogo82148/actions-upload-release-asset@610b1987249a69a79de9565777e112fb38f22436 # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
          with:
              upload_url: ${{ inputs.upload-url }}
              asset_path: ${{ inputs.asset-path }}.asc

        - name: Upload assets
-          uses: shogo82148/actions-upload-release-asset@610b1987249a69a79de9565777e112fb38f22436 # v1
+          uses: shogo82148/actions-upload-release-asset@59cbc563d11314e48122193f8fe5cdda62ea6cf9 # v1
          with:
              upload_url: ${{ inputs.upload-url }}
              asset_path: ${{ inputs.asset-path }}
@@ -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"
@@ -15,7 +15,7 @@ jobs:
            deployments: write
        steps:
            - name: 📥 Download artifact
-              uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
                  run-id: ${{ github.event.workflow_run.id }}
@@ -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 }}
@@ -35,7 +35,7 @@ jobs:
            pull-requests: read
        steps:
            - name: Add notice
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              if: contains(github.event.pull_request.labels.*.name, 'X-Blocked')
              with:
                  script: |
@@ -49,7 +49,7 @@ jobs:
            pull-requests: write
        steps:
            - name: Check membership
-              if: github.event.pull_request.user.login != 'renovate[bot]'
+              if: github.event.pull_request.user.login != 'renovate[bot]' && github.event.pull_request.user.login != 'dependabot[bot]'
              uses: tspascoal/get-user-teams-membership@57e9f42acd78f4d0f496b3be4368fc5f62696662 # v3
              id: teams
              with:
@@ -60,7 +60,7 @@ jobs:

            - name: Add label
              if: steps.teams.outputs.isTeamMember == 'false'
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              with:
                  script: |
                      github.rest.issues.addLabels({
@@ -73,13 +73,15 @@ 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.event.pull_request.head.repo.full_name != github.repository
        steps:
            - name: Close pull request
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              with:
                  script: |
                      github.rest.issues.createComment({
@@ -18,7 +18,7 @@ jobs:
        runs-on: ubuntu-24.04
        steps:
            - name: Check for X-Release-Blocker label on any open issues or PRs
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              env:
                  REPO: ${{ inputs.repository }}
              with:
@@ -16,12 +16,12 @@ jobs:
            contents: write
        steps:
            - name: 🧮 Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  ref: staging
                  fetch-depth: 0

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  node-version-file: package.json
                  cache: "yarn"
@@ -37,7 +37,7 @@ jobs:
                  disable-autolabeler: true

            - name: Get actions scripts
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -48,7 +48,7 @@ jobs:

            - name: Ingest upstream changes
              if: inputs.include-changes
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              env:
                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
@@ -18,14 +18,14 @@ jobs:
    merge:
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -33,7 +33,7 @@ jobs:
                  sparse-checkout: |
                      scripts/release

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version-file: package.json
@@ -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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -106,7 +104,7 @@ jobs:
              run: echo "VERSION=$(echo $VERSION | cut -d- -f1)" >> $GITHUB_ENV

            - name: Check version number not in use
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              with:
                  script: |
                      const { VERSION } = process.env;
@@ -125,7 +123,7 @@ jobs:
                  git config --global user.email "releases@riot.im"
                  git config --global user.name "RiotRobot"

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version-file: package.json
@@ -218,7 +216,7 @@ jobs:

            - name: Validate release has expected assets
              if: inputs.expected-asset-count
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              env:
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  EXPECTED_ASSET_COUNT: ${{ inputs.expected-asset-count }}
@@ -246,7 +244,7 @@ jobs:
                  git push origin master

            - name: Publish release
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8
              env:
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  FINAL: ${{ inputs.final }}
@@ -282,8 +280,6 @@ jobs:
        permissions:
            contents: read
            id-token: write
-        secrets:
-            NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

    post-release:
        name: Post release steps
@@ -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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  ref: staging

            - name: 🔧 Yarn cache
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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' }}
@@ -44,13 +44,13 @@ jobs:
                repo:
                    - element-hq/element-web
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  repository: ${{ matrix.repo }}
                  ref: staging
                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version: "lts/*"
@@ -73,10 +73,10 @@ jobs:
        runs-on: ubuntu-24.04
        steps:
            - name: 🧮 Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

            - name: 🔧 Yarn cache
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version-file: package.json
@@ -88,7 +88,7 @@ jobs:
              run: yarn gendoc

            - name: Upload artifact
-              uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3
+              uses: actions/upload-pages-artifact@7b1f4a764d45c48632c6b24a0339c27f5614fb0b # v4
              with:
                  path: _docs

@@ -27,7 +27,7 @@ jobs:
        steps:
            # We create the status here and then update it to success/failure in the `report` stage
            # This provides an easy link to this workflow_run from the PR before Sonarcloud is done.
-            - uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+            - uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
                  state: pending
@@ -36,14 +36,14 @@ jobs:
                  target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}

            - name: "🧮 Checkout code"
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # 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@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              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@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              uses: actions/download-artifact@018cc2cf5baa6db3ef3c5f8a56943fffe632ef53 # v6
              if: inputs.sharded
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -75,19 +75,20 @@ jobs:

            - name: "🩻 SonarCloud Scan"
              id: sonarcloud
-              uses: matrix-org/sonarcloud-workflow-action@820f7c2e9e94ba9e35add0f739691e5c7e23fa25 # v4.0
+              uses: matrix-org/sonarcloud-workflow-action@9d9692c97a426ea43f5b578c6bc8f952a867cd49
              # 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 }}
                  token: ${{ secrets.SONAR_TOKEN }}

-            - uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+            - uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
              if: always()
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
@@ -14,9 +14,9 @@ jobs:
        name: "Typescript Syntax Check"
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version-file: package.json
@@ -61,7 +61,7 @@ jobs:
            - name: Build Types
              run: "yarn build:types"

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
              with:
                  repository: element-hq/element-web

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # v6
              with:
                  cache: "yarn"
                  node-version: "lts/*"
@@ -22,11 +22,11 @@ jobs:
                node: ["lts/*", 22]
        steps:
            - name: Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6

            - name: Setup Node
              id: setupNode
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@395ad3262231945c25e8478fd5baf05154b1d79f # 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: |
@@ -116,7 +116,7 @@ jobs:
        steps:
            - name: Skip SonarCloud on merge queues
              if: env.ENABLE_COVERAGE == 'false'
-              uses: guibranco/github-status-action-v2@741ea90ba6c3ca76fe0d43ba11a90cda97d5e685
+              uses: guibranco/github-status-action-v2@5530c593759f489bba08272e96986ffc571c1ea1
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
                  state: success
@@ -12,7 +12,7 @@ jobs:
            issues: write
            pull-requests: write
        steps:
-            - uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9
+            - uses: actions/stale@997185467fa4f803885201cee163a9f38240193d # v10
              with:
                  operations-per-run: 250
                  days-before-issue-stale: -1
@@ -1,3 +1,185 @@
+Changes in [40.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v40.0.0) (2026-01-13)
+==================================================================================================
+## 🚨 BREAKING CHANGES
+
+* MatrixRTC Pseudonymous livekit identities ([#5110](https://github.com/matrix-org/matrix-js-sdk/pull/5110)). Contributed by @toger5.
+
+## 🦖 Deprecations
+
+* Mark `forwardingCurve25519KeyChain` as deprecated ([#5111](https://github.com/matrix-org/matrix-js-sdk/pull/5111)). Contributed by @richvdh.
+* Mark `IEventDecryptionResult` as deprecated ([#5112](https://github.com/matrix-org/matrix-js-sdk/pull/5112)). Contributed by @richvdh.
+
+## ✨ Features
+
+* Implement MSC4387: M\_SAFETY error ([#5107](https://github.com/matrix-org/matrix-js-sdk/pull/5107)). Contributed by @Half-Shot.
+* Implement \_unstable\_getRTCTransports for MSC4143 ([#5104](https://github.com/matrix-org/matrix-js-sdk/pull/5104)). Contributed by @Half-Shot.
+* Use `membershipID` for session events ([#5105](https://github.com/matrix-org/matrix-js-sdk/pull/5105)). Contributed by @toger5.
+
+## 🐛 Bug Fixes
+
+* Make MatrixRTC encryption key types narrower for TS 5.9 compatibility ([#5117](https://github.com/matrix-org/matrix-js-sdk/pull/5117)). Contributed by @robintown.
+* Re-check outgoing requests after processing them ([#5109](https://github.com/matrix-org/matrix-js-sdk/pull/5109)). Contributed by @andybalaam.
+* Make token refresher init itself lazily ([#5106](https://github.com/matrix-org/matrix-js-sdk/pull/5106)). Contributed by @dbkr.
+
+
+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
+
+* [MatrixRTC] Multi SFU support + m.rtc.member event type support ([#5022](https://github.com/matrix-org/matrix-js-sdk/pull/5022)). Contributed by @toger5.
+
+## ✨ Features
+
+* [MatrixRTC] Multi SFU support + m.rtc.member event type support ([#5022](https://github.com/matrix-org/matrix-js-sdk/pull/5022)). Contributed by @toger5.
+* Implement Sticky Events MSC4354 ([#5028](https://github.com/matrix-org/matrix-js-sdk/pull/5028)). Contributed by @Half-Shot.
+* feat(client): allow disabling VoIP support ([#5021](https://github.com/matrix-org/matrix-js-sdk/pull/5021)). Contributed by @pkuzco.
+
+## 🐛 Bug Fixes
+
+* Only use the first 3 viaServers specified ([#5034](https://github.com/matrix-org/matrix-js-sdk/pull/5034)). Contributed by @t3chguy.
+* Fetch the user's device info before processing a verification request ([#5030](https://github.com/matrix-org/matrix-js-sdk/pull/5030)). Contributed by @andybalaam.
+
+
+Changes in [38.4.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.4.0) (2025-10-07)
+==================================================================================================
+## ✨ Features
+
+* Add call intent to RTC call notifications ([#5010](https://github.com/matrix-org/matrix-js-sdk/pull/5010)). Contributed by @Half-Shot.
+* Implement experimental encrypted state events. ([#4994](https://github.com/matrix-org/matrix-js-sdk/pull/4994)). Contributed by @kaylendog.
+
+## 🐛 Bug Fixes
+
+* Exclude cancelled requests from in-progress lists ([#5016](https://github.com/matrix-org/matrix-js-sdk/pull/5016)). Contributed by @andybalaam.
+
+
+Changes in [38.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.3.0) (2025-09-23)
+==================================================================================================
+## 🐛 Bug Fixes
+
+* Remove knocked room when membership changes to join ([#4977](https://github.com/matrix-org/matrix-js-sdk/pull/4977)). Contributed by @svajunas-budrys.
+
+
+Changes in [38.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.2.0) (2025-09-16)
+==================================================================================================
+Fix [CVE-2025-59160](https://www.cve.org/CVERecord?id=CVE-2025-59160) / [GHSA-mp7c-m3rh-r56v](https://github.com/matrix-org/matrix-js-sdk/security/advisories/GHSA-mp7c-m3rh-r56v)
+
+
+
+Changes in [38.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.1.0) (2025-09-09)
+==================================================================================================
+## ✨ Features
+
+* Remove custom `org.matrix.msc4075.rtc.notification.parent` relation type ([#4979](https://github.com/matrix-org/matrix-js-sdk/pull/4979)). Contributed by @toger5.
+* MatrixRTC: Add RTC decline event ([#4978](https://github.com/matrix-org/matrix-js-sdk/pull/4978)). Contributed by @toger5.
+* Make a MatrixRTCSession emit once the RTCNotification is sent ([#4976](https://github.com/matrix-org/matrix-js-sdk/pull/4976)). Contributed by @toger5.
+* Use hydra semantics for unknown room versions ([#4957](https://github.com/matrix-org/matrix-js-sdk/pull/4957)). Contributed by @dbkr.
+* Expose the StatusChanged event through the RTCSession ([#4974](https://github.com/matrix-org/matrix-js-sdk/pull/4974)). Contributed by @toger5.
+* Add `probablyLeft` event to the MatrixRTCSession ([#4962](https://github.com/matrix-org/matrix-js-sdk/pull/4962)). Contributed by @toger5.
+
+## 🐛 Bug Fixes
+
+* Fix `m.topic` format ([#4984](https://github.com/matrix-org/matrix-js-sdk/pull/4984)). Contributed by @tulir.
+* Fix stable-suffixed MSC4133 support ([#4983](https://github.com/matrix-org/matrix-js-sdk/pull/4983)). Contributed by @dbkr.
+* Fix thread edit aggregation race condition ([#4980](https://github.com/matrix-org/matrix-js-sdk/pull/4980)). Contributed by @basnijholt.
+
+
+Changes in [38.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v38.0.0) (2025-08-27)
+==================================================================================================
+## 🚨 BREAKING CHANGES
+
+* Release tranche of breaking changes ([#4975](https://github.com/matrix-org/matrix-js-sdk/pull/4975)). 
+* Remove support for FetchHttpApi `onlyData = false`
+* Remove deprecated `IJoinRoomOpts.syncRoom`
+* Remove deprecated methods which are unsupported in rust crypto
+* Remove deprecated getAuthIssuer method
+* Remove deprecated beginKeyVerification method
+* Remove deprecated isEncryptedDisabledForUnverifiedDevices getter 
+* Remove deprecated UndecryptableToDeviceEvent MatrixClient emit
+* Remove deprecated defer utility method
+* Remove deprecated UIAResponse dummy type 
+* Remove deprecated MatrixRTCSession MembershipConfig fields 
+* Remove deprecated findVerificationRequestDMInProgress and storeSessionBackupPrivateKey methods in favour of overloads
+
+## ✨ Features
+
+* Allow multiple rtc sessions per room (with different sessionDescriptions) ([#4945](https://github.com/matrix-org/matrix-js-sdk/pull/4945)). Contributed by @toger5.
+* Add support for login\_hint in authorization url generation ([#4943](https://github.com/matrix-org/matrix-js-sdk/pull/4943)). Contributed by @odelcroi.
+* Only process MatrixRTC sessions associated with calls for `callMembershipsForRoom` ([#4960](https://github.com/matrix-org/matrix-js-sdk/pull/4960)). Contributed by @fkwp.
+
+
+Changes in [37.13.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v37.13.0) (2025-08-11)
+====================================================================================================
+This release supports new v12 Matrix rooms and consequently has a breaking change, removing powerLevelNorm from the RoomMember object as this can't be supported with infinite power levels. Apps should use the non-normalised `powerLevel` instead.
+
+## 🚨 BREAKING CHANGES
+
+* [Backport staging] Support for creator power level ([#4954](https://github.com/matrix-org/matrix-js-sdk/pull/4954)). Contributed by @RiotRobot.
+
+## ✨ Features
+
+* [Backport staging] Support v12 rooms in maySendEvent ([#4956](https://github.com/matrix-org/matrix-js-sdk/pull/4956)). Contributed by @RiotRobot.
+* [Backport staging] Support for creator power level ([#4954](https://github.com/matrix-org/matrix-js-sdk/pull/4954)). Contributed by @RiotRobot.
+* Experimental support for sharing encrypted history on invite ([#4920](https://github.com/matrix-org/matrix-js-sdk/pull/4920)). Contributed by @richvdh.
+* Use the logger associated with MatrixClient in rust sdk ([#4918](https://github.com/matrix-org/matrix-js-sdk/pull/4918)). Contributed by @richvdh.
+* Update to matrix-sdk-crypto-wasm 15.1.0, and add new `ShieldStateCode.MismatchedSender` ([#4916](https://github.com/matrix-org/matrix-js-sdk/pull/4916)). Contributed by @richvdh.
+
+## 🐛 Bug Fixes
+
+* Fix unknown/broken state in the RTC Membership Manager causing unnecassary error logging. ([#4944](https://github.com/matrix-org/matrix-js-sdk/pull/4944)). Contributed by @toger5.
+
+
 Changes in [37.12.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v37.12.0) (2025-07-29)
 ====================================================================================================
 ## 🦖 Deprecations
@@ -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
        ) {
            // ...
        }
@@ -23,6 +23,7 @@ const config: Config = {
    collectCoverageFrom: ["<rootDir>/src/**/*.{js,ts}"],
    coverageReporters: ["text-summary", "lcov"],
    testResultsProcessor: "@casualbot/jest-sonar-reporter",
+    transformIgnorePatterns: ["/node_modules/(?!(uuid|p-retry|is-network-error)).+$"],

    // Always print out a summary if there are any failing tests. Normally
    // a summary is only printed if there are more than 20 test *suites*.
@@ -12,10 +12,6 @@ export default {
        "src/utils.ts", // not really an entrypoint but we have deprecated `defer` there
        "scripts/**",
        "spec/**",
-        // XXX: these look entirely unused
-        "src/crypto/aes.ts",
-        "src/crypto/crypto.ts",
-        "src/crypto/recoverykey.ts",
        // XXX: these should be re-exported by one of the supported exports
        "src/matrixrtc/index.ts",
        "src/sliding-sync.ts",
@@ -38,6 +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`
@@ -1,6 +1,6 @@
 {
    "name": "matrix-js-sdk",
-    "version": "37.13.0-rc.0",
+    "version": "40.0.0",
    "description": "Matrix Client-Server SDK for Javascript",
    "engines": {
        "node": ">=22.0.0"
@@ -49,19 +49,19 @@
    ],
    "dependencies": {
        "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^15.1.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^16.0.0",
        "another-json": "^0.2.0",
        "bs58": "^6.0.0",
        "content-type": "^1.0.4",
        "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": "4",
-        "sdp-transform": "^2.14.1",
+        "p-retry": "7",
+        "sdp-transform": "^3.0.0",
        "unhomoglyph": "^1.0.6",
-        "uuid": "11"
+        "uuid": "13"
    },
    "devDependencies": {
        "@action-validator/cli": "^0.6.0",
@@ -78,18 +78,18 @@
        "@babel/plugin-transform-runtime": "^7.12.10",
        "@babel/preset-env": "^7.12.11",
        "@babel/preset-typescript": "^7.12.7",
-        "@casualbot/jest-sonar-reporter": "2.2.7",
+        "@casualbot/jest-sonar-reporter": "2.5.0",
        "@matrix-org/olm": "3.2.15",
        "@peculiar/webcrypto": "^1.4.5",
        "@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",
@@ -97,25 +97,25 @@
        "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",
        "node-fetch": "^2.7.0",
-        "prettier": "3.6.2",
+        "prettier": "3.7.0",
        "rimraf": "^6.0.0",
        "ts-node": "^10.9.2",
        "typedoc": "^0.28.1",
@@ -403,7 +403,7 @@ describe("cross-signing", () => {
            const isCrossSigningReady = await aliceClient.getCrypto()!.isCrossSigningReady();

            expect(isCrossSigningReady).toBeFalsy();
-        });
+        }, 10000);
    });

    describe("getCrossSigningKeyId", () => {
@@ -88,7 +88,10 @@ import {
    encryptMegolmEventRawPlainText,
    establishOlmSession,
    getTestOlmAccountKeys,
-} from "./olm-utils";
+    expectSendRoomKey,
+    expectSendMegolmMessageEvent,
+    expectEncryptedSendMessageEvent,
+} from "./olm-utils.ts";
 import { AccountDataAccumulator } from "../../test-utils/AccountDataAccumulator";
 import { UNSIGNED_MEMBERSHIP_FIELD } from "../../../src/@types/event";
 import { KnownMembership } from "../../../src/@types/membership";
@@ -104,107 +107,6 @@ afterEach(() => {
    jest.useRealTimers();
 });

-/**
- * Expect that the client shares keys with the given recipient
- *
- * Waits for an HTTP request to send the encrypted m.room_key to-device message; decrypts it and uses it
- * to establish an Olm InboundGroupSession.
- *
- * @param recipientUserID - the user id of the expected recipient
- *
- * @param recipientOlmAccount - Olm.Account for the recipient
- *
- * @param recipientOlmSession - an Olm.Session for the recipient, which must already have exchanged pre-key
- *    messages with the sender. Alternatively, null, in which case we will expect a pre-key message.
- *
- * @returns the established inbound group session
- */
-async function expectSendRoomKey(
-    recipientUserID: string,
-    recipientOlmAccount: Olm.Account,
-    recipientOlmSession: Olm.Session | null = null,
-): Promise<Olm.InboundGroupSession> {
-    const testRecipientKey = JSON.parse(recipientOlmAccount.identity_keys())["curve25519"];
-
-    function onSendRoomKey(content: any): Olm.InboundGroupSession {
-        const m = content.messages[recipientUserID].DEVICE_ID;
-        const ct = m.ciphertext[testRecipientKey];
-
-        if (!recipientOlmSession) {
-            expect(ct.type).toEqual(0); // pre-key message
-            recipientOlmSession = new Olm.Session();
-            recipientOlmSession.create_inbound(recipientOlmAccount, ct.body);
-        } else {
-            expect(ct.type).toEqual(1); // regular message
-        }
-
-        const decrypted = JSON.parse(recipientOlmSession.decrypt(ct.type, ct.body));
-        expect(decrypted.type).toEqual("m.room_key");
-        const inboundGroupSession = new Olm.InboundGroupSession();
-        inboundGroupSession.create(decrypted.content.session_key);
-        return inboundGroupSession;
-    }
-    return await new Promise<Olm.InboundGroupSession>((resolve) => {
-        fetchMock.putOnce(
-            new RegExp("/sendToDevice/m.room.encrypted/"),
-            (url: string, opts: RequestInit): FetchMock.MockResponse => {
-                const content = JSON.parse(opts.body as string);
-                resolve(onSendRoomKey(content));
-                return {};
-            },
-            {
-                // append to the list of intercepts on this path (since we have some tests that call
-                // this function multiple times)
-                overwriteRoutes: false,
-            },
-        );
-    });
-}
-
-/**
- * Return the event received on rooms/{roomId}/send/m.room.encrypted endpoint.
- * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
- * @returns the content of the encrypted event
- */
-function expectEncryptedSendMessage() {
-    return new Promise<IContent>((resolve) => {
-        fetchMock.putOnce(
-            new RegExp("/send/m.room.encrypted/"),
-            (url, request) => {
-                const content = JSON.parse(request.body as string);
-                resolve(content);
-                return { event_id: "$event_id" };
-            },
-            // append to the list of intercepts on this path (since we have some tests that call
-            // this function multiple times)
-            { overwriteRoutes: false },
-        );
-    });
-}
-
-/**
- * Expect that the client sends an encrypted event
- *
- * Waits for an HTTP request to send an encrypted message in the test room.
- *
- * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
- *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
- *
- * @returns The content of the successfully-decrypted event
- */
-async function expectSendMegolmMessage(
-    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
-): Promise<Partial<IEvent>> {
-    const encryptedMessageContent = await expectEncryptedSendMessage();
-
-    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
-    const inboundGroupSession = await inboundGroupSessionPromise;
-
-    const r: any = inboundGroupSession.decrypt(encryptedMessageContent!.ciphertext);
-    logger.log("Decrypted received megolm message", r);
-    return JSON.parse(r.plaintext);
-}
-
 describe("crypto", () => {
    let testOlmAccount = {} as unknown as Olm.Account;
    let testSenderKey = "";
@@ -991,7 +893,7 @@ describe("crypto", () => {
        // Finally, send the message, and expect to get an `m.room.encrypted` event that we can decrypt.
        await Promise.all([
            aliceClient.sendTextMessage(ROOM_ID, "test"),
-            expectSendMegolmMessage(inboundGroupSessionPromise),
+            expectSendMegolmMessageEvent(inboundGroupSessionPromise),
        ]);
    });

@@ -1018,7 +920,7 @@ describe("crypto", () => {
        // Send the first message, and check we can decrypt it.
        await Promise.all([
            aliceClient.sendTextMessage(ROOM_ID, "test"),
-            expectSendMegolmMessage(inboundGroupSessionPromise),
+            expectSendMegolmMessageEvent(inboundGroupSessionPromise),
        ]);

        // Finally the interesting part: discard the session.
@@ -1026,7 +928,7 @@ describe("crypto", () => {

        // Now when we send the next message, we should get a *new* megolm session.
        const inboundGroupSessionPromise2 = expectSendRoomKey("@bob:xyz", testOlmAccount);
-        const p2 = expectSendMegolmMessage(inboundGroupSessionPromise2);
+        const p2 = expectSendMegolmMessageEvent(inboundGroupSessionPromise2);
        await Promise.all([aliceClient.sendTextMessage(ROOM_ID, "test2"), p2]);
    });

@@ -1037,7 +939,7 @@ describe("crypto", () => {
         */
        async function sendEncryptedMessage(): Promise<IContent> {
            const [encryptedMessage] = await Promise.all([
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
                aliceClient.sendTextMessage(ROOM_ID, "test"),
            ]);
            return encryptedMessage;
@@ -1159,7 +1061,7 @@ describe("crypto", () => {
        let [, , encryptedMessage] = await Promise.all([
            aliceClient.sendTextMessage(ROOM_ID, "test"),
            expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession),
-            expectEncryptedSendMessage(),
+            expectEncryptedSendMessageEvent(),
        ]);

        // Check that the session id exists
@@ -1187,7 +1089,7 @@ describe("crypto", () => {
        [, , encryptedMessage] = await Promise.all([
            aliceClient.sendTextMessage(ROOM_ID, "test"),
            expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession),
-            expectEncryptedSendMessage(),
+            expectEncryptedSendMessageEvent(),
        ]);

        // Check that the new session id exists
@@ -1385,7 +1287,7 @@ describe("crypto", () => {
            const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession);

            // and finally the megolm message
-            const megolmMessagePromise = expectSendMegolmMessage(inboundGroupSessionPromise);
+            const megolmMessagePromise = expectSendMegolmMessageEvent(inboundGroupSessionPromise);

            // kick it off
            const sendPromise = aliceClient.sendTextMessage(ROOM_ID, "test");
@@ -1408,7 +1310,7 @@ describe("crypto", () => {
            const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount, p2pSession);

            // and finally the megolm message
-            const megolmMessagePromise = expectSendMegolmMessage(inboundGroupSessionPromise);
+            const megolmMessagePromise = expectSendMegolmMessageEvent(inboundGroupSessionPromise);

            // kick it off
            const sendPromise = aliceClient.sendTextMessage(ROOM_ID, "test");
@@ -1491,8 +1393,10 @@ describe("crypto", () => {

                    expect(ev.decryptionFailureReason).toEqual(expectedErrorCode);

-                    // `isEncryptedDisabledForUnverifiedDevices` should be true for `m.unverified` and false for other errors.
-                    expect(ev.isEncryptedDisabledForUnverifiedDevices).toEqual(withheldCode === "m.unverified");
+                    // `decryptionFailureReason` should be `MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE` for `m.unverified`
+                    expect(
+                        ev.decryptionFailureReason === DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+                    ).toEqual(withheldCode === "m.unverified");
                });
            },
        );
@@ -2298,7 +2202,7 @@ describe("crypto", () => {
            await syncPromise(client1);

            // Send a message, and expect to get an `m.room.encrypted` event.
-            await Promise.all([client1.sendTextMessage(ROOM_ID, "test"), expectEncryptedSendMessage()]);
+            await Promise.all([client1.sendTextMessage(ROOM_ID, "test"), expectEncryptedSendMessageEvent()]);

            // We now replace the client, and allow the new one to resync, *without* the encryption event.
            client2 = await replaceClient(client1);
@@ -2319,7 +2223,7 @@ describe("crypto", () => {
            // Send a message, and expect to get an `m.room.encrypted` event.
            const [, msg1Content] = await Promise.all([
                client1.sendTextMessage(ROOM_ID, "test1"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
            ]);

            // Replace the state with one which bumps the rotation period. This should be ignored, though it's not
@@ -2338,12 +2242,12 @@ describe("crypto", () => {
            // use a different one.
            const [, msg2Content] = await Promise.all([
                client1.sendTextMessage(ROOM_ID, "test2"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
            ]);
            expect(msg2Content.session_id).toEqual(msg1Content.session_id);
            const [, msg3Content] = await Promise.all([
                client1.sendTextMessage(ROOM_ID, "test3"),
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
            ]);
            expect(msg3Content.session_id).not.toEqual(msg1Content.session_id);
        });
@@ -2355,7 +2259,7 @@ describe("crypto", () => {
            await syncPromise(client1);

            // Send a message, and expect to get an `m.room.encrypted` event.
-            await Promise.all([client1.sendTextMessage(ROOM_ID, "test1"), expectEncryptedSendMessage()]);
+            await Promise.all([client1.sendTextMessage(ROOM_ID, "test1"), expectEncryptedSendMessageEvent()]);

            // We now replace the client, and allow the new one to resync with a *different* encryption event.
            client2 = await replaceClient(client1);
@@ -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();
@@ -16,6 +16,7 @@ limitations under the License.

 import Olm from "@matrix-org/olm";
 import anotherjson from "another-json";
+import fetchMock from "fetch-mock-jest";

 import {
    type IContent,
@@ -30,6 +31,8 @@ import { type IE2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
 import { type ISyncResponder } from "../../test-utils/SyncResponder";
 import { syncPromise } from "../../test-utils/test-utils";
 import { type KeyBackupInfo } from "../../../src/crypto-api";
+import { logger } from "../../../src/logger";
+import type FetchMock from "fetch-mock";

 /**
 * @module
@@ -302,6 +305,9 @@ export function encryptMegolmEventRawPlainText(opts: {
        },
        type: "m.room.encrypted",
        unsigned: {},
+        state_key: opts.plaintext.hasOwnProperty("state_key")
+            ? `${opts.plaintext.type}:${opts.plaintext.state_key}`
+            : undefined,
    };
 }

@@ -414,3 +420,148 @@ export async function establishOlmSession(
    await syncPromise(testClient);
    return p2pSession;
 }
+
+/**
+ * Expect that the client shares keys with the given recipient
+ *
+ * Waits for an HTTP request to send the encrypted m.room_key to-device message; decrypts it and uses it
+ * to establish an Olm InboundGroupSession.
+ *
+ * @param recipientUserID - the user id of the expected recipient
+ *
+ * @param recipientOlmAccount - Olm.Account for the recipient
+ *
+ * @param recipientOlmSession - an Olm.Session for the recipient, which must already have exchanged pre-key
+ *    messages with the sender. Alternatively, null, in which case we will expect a pre-key message.
+ *
+ * @returns the established inbound group session
+ */
+export async function expectSendRoomKey(
+    recipientUserID: string,
+    recipientOlmAccount: Olm.Account,
+    recipientOlmSession: Olm.Session | null = null,
+): Promise<Olm.InboundGroupSession> {
+    const testRecipientKey = JSON.parse(recipientOlmAccount.identity_keys())["curve25519"];
+
+    function onSendRoomKey(content: any): Olm.InboundGroupSession {
+        const m = content.messages[recipientUserID].DEVICE_ID;
+        const ct = m.ciphertext[testRecipientKey];
+
+        if (!recipientOlmSession) {
+            expect(ct.type).toEqual(0); // pre-key message
+            recipientOlmSession = new Olm.Session();
+            recipientOlmSession.create_inbound(recipientOlmAccount, ct.body);
+        } else {
+            expect(ct.type).toEqual(1); // regular message
+        }
+
+        const decrypted = JSON.parse(recipientOlmSession.decrypt(ct.type, ct.body));
+        expect(decrypted.type).toEqual("m.room_key");
+        const inboundGroupSession = new Olm.InboundGroupSession();
+        inboundGroupSession.create(decrypted.content.session_key);
+        return inboundGroupSession;
+    }
+    return await new Promise<Olm.InboundGroupSession>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/sendToDevice/m.room.encrypted/"),
+            (url: string, opts: RequestInit): FetchMock.MockResponse => {
+                const content = JSON.parse(opts.body as string);
+                resolve(onSendRoomKey(content));
+                return {};
+            },
+            {
+                // append to the list of intercepts on this path (since we have some tests that call
+                // this function multiple times)
+                overwriteRoutes: false,
+            },
+        );
+    });
+}
+
+/**
+ * Return the event received on rooms/{roomId}/send/m.room.encrypted endpoint.
+ * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidsendeventtypetxnid
+ * @returns the content of the encrypted event
+ */
+export function expectEncryptedSendMessageEvent() {
+    return new Promise<IContent>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/send/m.room.encrypted/"),
+            (url, request) => {
+                const content = JSON.parse(request.body as string);
+                resolve(content);
+                return { event_id: "$event_id" };
+            },
+            // append to the list of intercepts on this path (since we have some tests that call
+            // this function multiple times)
+            { overwriteRoutes: false },
+        );
+    });
+}
+
+/**
+ * Return the event received on rooms/{roomId}/state/m.room.encrypted/{stateKey} endpoint.
+ * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidstateeventtypestatekey
+ * @returns the content of the encrypted event
+ */
+function expectEncryptedSendStateEvent() {
+    return new Promise<IContent>((resolve) => {
+        fetchMock.putOnce(
+            new RegExp("/state/m.room.encrypted/"),
+            (url, request) => {
+                const content = JSON.parse(request.body as string);
+                resolve(content);
+                return { event_id: "$event_id" };
+            },
+            // append to the list of intercepts on this path (since we have some tests that call
+            // this function multiple times)
+            { overwriteRoutes: false },
+        );
+    });
+}
+
+/**
+ * Expect that the client sends an encrypted message event
+ *
+ * Waits for an HTTP request to send an encrypted message in the test room.
+ *
+ * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
+ *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
+ *
+ * @returns The content of the successfully-decrypted event
+ */
+export async function expectSendMegolmMessageEvent(
+    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
+): Promise<Partial<IEvent>> {
+    const encryptedMessageContent = await expectEncryptedSendMessageEvent();
+
+    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
+    const inboundGroupSession = await inboundGroupSessionPromise;
+
+    const r: any = inboundGroupSession.decrypt(encryptedMessageContent!.ciphertext);
+    logger.log("Decrypted received megolm message", r);
+    return JSON.parse(r.plaintext);
+}
+
+/**
+ * Expect that the client sends an encrypted state event
+ *
+ * Waits for an HTTP request to send an encrypted state event in the test room.
+ *
+ * @param inboundGroupSessionPromise - a promise for an Olm InboundGroupSession, which will
+ *    be used to decrypt the event. We will wait for this to resolve once the HTTP request has been processed.
+ *
+ * @returns The content of the successfully-decrypted state event
+ */
+export async function expectSendMegolmStateEvent(
+    inboundGroupSessionPromise: Promise<Olm.InboundGroupSession>,
+): Promise<Partial<IEvent>> {
+    const encryptedStateContent = await expectEncryptedSendStateEvent();
+
+    // In some of the tests, the room key is sent *after* the actual event, so we may need to wait for it now.
+    const inboundGroupSession = await inboundGroupSessionPromise;
+
+    const r: any = inboundGroupSession.decrypt(encryptedStateContent!.ciphertext);
+    logger.log("Decrypted received megolm state event", r);
+    return JSON.parse(r.plaintext);
+}
@@ -0,0 +1,219 @@
+/*
+Copyright 2025 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import anotherjson from "another-json";
+import fetchMock from "fetch-mock-jest";
+import "fake-indexeddb/auto";
+import Olm from "@matrix-org/olm";
+
+import * as testUtils from "../../test-utils/test-utils";
+import { getSyncResponse, syncPromise } from "../../test-utils/test-utils";
+import { TEST_ROOM_ID as ROOM_ID } from "../../test-utils/test-data";
+import { logger } from "../../../src/logger";
+import { createClient, PendingEventOrdering, type IStartClientOpts, type MatrixClient } from "../../../src/matrix";
+import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
+import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder";
+import { type ISyncResponder, SyncResponder } from "../../test-utils/SyncResponder";
+import {
+    createOlmAccount,
+    createOlmSession,
+    encryptGroupSessionKey,
+    encryptMegolmEvent,
+    getTestOlmAccountKeys,
+    expectSendRoomKey,
+    expectSendMegolmStateEvent,
+} from "./olm-utils";
+import { mockInitialApiRequests } from "../../test-utils/mockEndpoints";
+
+describe("Encrypted State Events", () => {
+    let testOlmAccount = {} as unknown as Olm.Account;
+    let testSenderKey = "";
+
+    /** the MatrixClient under test */
+    let aliceClient: MatrixClient;
+
+    /** an object which intercepts `/keys/upload` requests from {@link #aliceClient} to catch the uploaded keys */
+    let keyReceiver: E2EKeyReceiver;
+
+    /** an object which intercepts `/sync` requests from {@link #aliceClient} */
+    let syncResponder: ISyncResponder;
+
+    async function startClientAndAwaitFirstSync(opts: IStartClientOpts = {}): Promise<void> {
+        logger.log(aliceClient.getUserId() + ": starting");
+
+        mockInitialApiRequests(aliceClient.getHomeserverUrl());
+
+        // we let the client do a very basic initial sync, which it needs before
+        // it will upload one-time keys.
+        syncResponder.sendOrQueueSyncResponse({ next_batch: 1 });
+
+        aliceClient.startClient({
+            // set this so that we can get hold of failed events
+            pendingEventOrdering: PendingEventOrdering.Detached,
+            ...opts,
+        });
+
+        await syncPromise(aliceClient);
+        logger.log(aliceClient.getUserId() + ": started");
+    }
+
+    beforeEach(async () => {
+        fetchMock.catch(404);
+        fetchMock.config.warnOnFallback = false;
+
+        const homeserverUrl = "https://alice-server.com";
+        aliceClient = createClient({
+            baseUrl: homeserverUrl,
+            userId: "@alice:localhost",
+            accessToken: "akjgkrgjs",
+            deviceId: "xzcvb",
+            logger: logger.getChild("aliceClient"),
+            enableEncryptedStateEvents: true,
+        });
+
+        keyReceiver = new E2EKeyReceiver(homeserverUrl);
+        syncResponder = new SyncResponder(homeserverUrl);
+
+        await aliceClient.initRustCrypto();
+
+        // create a test olm device which we will use to communicate with alice. We use libolm to implement this.
+        testOlmAccount = await createOlmAccount();
+        const testE2eKeys = JSON.parse(testOlmAccount.identity_keys());
+        testSenderKey = testE2eKeys.curve25519;
+    }, 10000);
+
+    afterEach(async () => {
+        await aliceClient.stopClient();
+        await jest.runAllTimersAsync();
+        fetchMock.mockReset();
+    });
+
+    function expectAliceKeyQuery(response: any) {
+        fetchMock.postOnce(new RegExp("/keys/query"), (url: string, opts: RequestInit) => response, {
+            overwriteRoutes: false,
+        });
+    }
+
+    function expectAliceKeyClaim(response: any) {
+        fetchMock.postOnce(new RegExp("/keys/claim"), response);
+    }
+
+    function getTestKeysClaimResponse(userId: string) {
+        testOlmAccount.generate_one_time_keys(1);
+        const testOneTimeKeys = JSON.parse(testOlmAccount.one_time_keys());
+        testOlmAccount.mark_keys_as_published();
+
+        const keyId = Object.keys(testOneTimeKeys.curve25519)[0];
+        const oneTimeKey: string = testOneTimeKeys.curve25519[keyId];
+        const unsignedKeyResult = { key: oneTimeKey };
+        const j = anotherjson.stringify(unsignedKeyResult);
+        const sig = testOlmAccount.sign(j);
+        const keyResult = {
+            ...unsignedKeyResult,
+            signatures: { [userId]: { "ed25519:DEVICE_ID": sig } },
+        };
+
+        return {
+            one_time_keys: { [userId]: { DEVICE_ID: { ["signed_curve25519:" + keyId]: keyResult } } },
+            failures: {},
+        };
+    }
+
+    it("Should receive an encrypted state event", async () => {
+        expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
+        await startClientAndAwaitFirstSync();
+
+        const p2pSession = await createOlmSession(testOlmAccount, keyReceiver);
+        const groupSession = new Olm.OutboundGroupSession();
+        groupSession.create();
+
+        // make the room_key event
+        const roomKeyEncrypted = encryptGroupSessionKey({
+            recipient: aliceClient.getUserId()!,
+            recipientCurve25519Key: keyReceiver.getDeviceKey(),
+            recipientEd25519Key: keyReceiver.getSigningKey(),
+            olmAccount: testOlmAccount,
+            p2pSession: p2pSession,
+            groupSession: groupSession,
+            room_id: ROOM_ID,
+        });
+
+        // encrypt a state event with the group session
+        const eventEncrypted = encryptMegolmEvent({
+            senderKey: testSenderKey,
+            groupSession: groupSession,
+            room_id: ROOM_ID,
+            plaintext: {
+                type: "m.room.topic",
+                state_key: "",
+                content: {
+                    topic: "Secret!",
+                },
+            },
+        });
+
+        // Alice gets both the events in a single sync
+        const syncResponse = {
+            next_batch: 1,
+            to_device: {
+                events: [roomKeyEncrypted],
+            },
+            rooms: {
+                join: {
+                    [ROOM_ID]: { timeline: { events: [eventEncrypted] } },
+                },
+            },
+        };
+
+        syncResponder.sendOrQueueSyncResponse(syncResponse);
+        await syncPromise(aliceClient);
+
+        const room = aliceClient.getRoom(ROOM_ID)!;
+        const event = room.getLiveTimeline().getEvents()[0];
+        expect(event.isEncrypted()).toBe(true);
+
+        // it probably won't be decrypted yet, because it takes a while to process the olm keys
+        const decryptedEvent = await testUtils.awaitDecryption(event, { waitOnDecryptionFailure: true });
+        expect(decryptedEvent.getContent().topic).toEqual("Secret!");
+    });
+
+    it("Should send an encrypted state event", async () => {
+        const homeserverUrl = aliceClient.getHomeserverUrl();
+        const keyResponder = new E2EKeyResponder(homeserverUrl);
+        keyResponder.addKeyReceiver("@alice:localhost", keyReceiver);
+
+        const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
+        keyResponder.addDeviceKeys(testDeviceKeys);
+
+        await startClientAndAwaitFirstSync();
+
+        // Alice shares a room with Bob
+        syncResponder.sendOrQueueSyncResponse(getSyncResponse(["@bob:xyz"], ROOM_ID, true));
+        await syncPromise(aliceClient);
+
+        // ... and claim one of Bob's OTKs ...
+        expectAliceKeyClaim(getTestKeysClaimResponse("@bob:xyz"));
+
+        // ... and send an m.room.topic message
+        const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount);
+
+        // Finally, send the message, and expect to get an `m.room.encrypted` event that we can decrypt.
+        await Promise.all([
+            aliceClient.setRoomTopic(ROOM_ID, "Secret!"),
+            expectSendMegolmStateEvent(inboundGroupSessionPromise),
+        ]);
+    });
+});
@@ -46,8 +46,8 @@ import {
    type Verifier,
    VerifierEvent,
 } from "../../../src/crypto-api/verification";
-import { escapeRegExp } from "../../../src/utils";
-import { awaitDecryption, emitPromise, getSyncResponse, syncPromise } from "../../test-utils/test-utils";
+import { escapeRegExp, sleep } from "../../../src/utils";
+import { awaitDecryption, emitPromise, getSyncResponse, syncPromise, waitFor } from "../../test-utils/test-utils";
 import { SyncResponder } from "../../test-utils/SyncResponder";
 import {
    BACKUP_DECRYPTION_KEY_BASE64,
@@ -79,11 +79,6 @@ import {
 import { type KeyBackupInfo, CryptoEvent } from "../../../src/crypto-api";
 import { encodeBase64 } from "../../../src/base64";

-// The verification flows use javascript timers to set timeouts. We tell jest to use mock timer implementations
-// to ensure that we don't end up with dangling timeouts.
-// But the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
-
 beforeAll(async () => {
    // we use the libolm primitives in the test, so init the Olm library
    await Olm.init();
@@ -96,6 +91,13 @@ beforeAll(async () => {
    await RustSdkCryptoJs.initAsync();
 }, 10000);

+beforeEach(() => {
+    // The verification flows use javascript timers to set timeouts. We tell jest to use mock timer implementations
+    // to ensure that we don't end up with dangling timeouts.
+    // But the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
+    jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+});
+
 afterEach(() => {
    // reset fake-indexeddb after each test, to make sure we don't leak connections
    // cf https://github.com/dumbmatter/fakeIndexedDB#wipingresetting-the-indexeddb-for-a-fresh-state
@@ -735,6 +737,35 @@ describe("verification", () => {
            expect(request.cancellingUserId).toEqual("@alice:localhost");
        });

+        it("does not include cancelled requests in the list of requests", async () => {
+            // Given Alice started a verification request
+            const [, request] = await Promise.all([
+                expectSendToDeviceMessage("m.key.verification.request"),
+                aliceClient.getCrypto()!.requestDeviceVerification(TEST_USER_ID, TEST_DEVICE_ID),
+            ]);
+            const transactionId = request.transactionId!;
+
+            returnToDeviceMessageFromSync(buildReadyMessage(transactionId, ["m.sas.v1"]));
+            await waitForVerificationRequestChanged(request);
+
+            // Sanity: the request is listed
+            const requestsBeforeCancel = aliceClient
+                .getCrypto()!
+                .getVerificationRequestsToDeviceInProgress(TEST_USER_ID);
+
+            expect(requestsBeforeCancel).toHaveLength(1);
+
+            // When Alice cancels it
+            await Promise.all([expectSendToDeviceMessage("m.key.verification.cancel"), request.cancel()]);
+
+            // Then it is no longer listed as in progress
+            const requestsAfterCancel = aliceClient
+                .getCrypto()!
+                .getVerificationRequestsToDeviceInProgress(TEST_USER_ID);
+
+            expect(requestsAfterCancel).toHaveLength(0);
+        });
+
        it("can cancel during the SAS phase", async () => {
            // have alice initiate a verification. She should send a m.key.verification.request
            const [, request] = await Promise.all([
@@ -1051,6 +1082,13 @@ describe("verification", () => {
        });

        it("ignores old verification requests", async () => {
+            const debug = jest.fn();
+            const info = jest.fn();
+            const warn = jest.fn();
+
+            // @ts-ignore overriding RustCrypto's logger
+            aliceClient.getCrypto()!.logger = { debug, info, warn };
+
            const eventHandler = jest.fn();
            aliceClient.on(CryptoEvent.VerificationRequestReceived, eventHandler);

@@ -1065,6 +1103,16 @@ describe("verification", () => {
            const matrixEvent = room.getLiveTimeline().getEvents()[0];
            expect(matrixEvent.getId()).toEqual(verificationRequestEvent.event_id);

+            // Wait until the request has been processed. We use a real sleep()
+            // here to make sure any background async tasks are completed.
+            jest.useRealTimers();
+            await waitFor(async () => {
+                expect(info).toHaveBeenCalledWith(
+                    expect.stringMatching(/^Ignoring just-received verification request/),
+                );
+                sleep(100);
+            });
+
            // check that an event has not been raised, and that the request is not found
            expect(eventHandler).not.toHaveBeenCalled();
            expect(
@@ -1072,6 +1120,29 @@ describe("verification", () => {
            ).not.toBeDefined();
        });

+        it("ignores cancelled verification requests", async () => {
+            // Given a verification request exists
+            const event = createVerificationRequestEvent();
+            returnRoomMessageFromSync(TEST_ROOM_ID, event);
+
+            // Wait for the request to be received
+            await emitPromise(aliceClient, CryptoEvent.VerificationRequestReceived);
+
+            const request = aliceClient.getCrypto()!.findVerificationRequestDMInProgress(TEST_ROOM_ID, "@bob:xyz");
+
+            // When I cancel it
+            fetchMock.put("express:/_matrix/client/v3/rooms/:roomId/send/m.key.verification.cancel/:id", {
+                event_id: event.event_id,
+            });
+            await request!.cancel();
+            expect(request!.phase).toEqual(VerificationPhase.Cancelled);
+
+            // Then it is no longer found
+            expect(
+                aliceClient.getCrypto()!.findVerificationRequestDMInProgress(TEST_ROOM_ID, "@bob:xyz"),
+            ).not.toBeDefined();
+        });
+
        it("Plaintext verification request from Bob to Alice", async () => {
            // Add verification request from Bob to Alice in the DM between them
            returnRoomMessageFromSync(TEST_ROOM_ID, createVerificationRequestEvent());
@@ -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(),
            ]);
        });
@@ -159,7 +159,7 @@ describe("MatrixClient opts", function () {

            await expect(
                Promise.all([client.sendTextMessage("!foo:bar", "a body", "txn1"), httpBackend.flush("/txn1", 1)]),
-            ).rejects.toThrow("MatrixError: [500] Unknown message");
+            ).rejects.toThrow("MatrixError: [500] Ruh roh");
        });

        it("shouldn't queue events", async () => {
@@ -63,7 +63,11 @@ export function syncPromise(client: MatrixClient, count = 1): Promise<void> {
 *
 * @returns the sync response
 */
-export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): ISyncResponse {
+export function getSyncResponse(
+    roomMembers: string[],
+    roomId = TEST_ROOM_ID,
+    encryptStateEvents = false,
+): ISyncResponse {
    const roomResponse: IJoinedRoom = {
        summary: {
            "m.heroes": [],
@@ -77,7 +81,8 @@ export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): I
                    type: "m.room.encryption",
                    state_key: "",
                    content: {
-                        algorithm: "m.megolm.v1.aes-sha2",
+                        "algorithm": "m.megolm.v1.aes-sha2",
+                        "io.element.msc4362.encrypt_state_events": encryptStateEvents,
                    },
                }),
            ],
@@ -183,39 +183,43 @@ describe("Topic content helpers", () => {
        it("creates fully defined event content without html", () => {
            expect(makeTopicContent("pizza")).toEqual({
                topic: "pizza",
-                [M_TOPIC.name]: [
-                    {
-                        body: "pizza",
-                        mimetype: "text/plain",
-                    },
-                ],
+                [M_TOPIC.name]: {
+                    "m.text": [
+                        {
+                            body: "pizza",
+                            mimetype: "text/plain",
+                        },
+                    ],
+                },
            });
        });

        it("creates fully defined event content with html", () => {
            expect(makeTopicContent("pizza", "<b>pizza</b>")).toEqual({
                topic: "pizza",
-                [M_TOPIC.name]: [
-                    {
-                        body: "<b>pizza</b>",
-                        mimetype: "text/html",
-                    },
-                    {
-                        body: "pizza",
-                        mimetype: "text/plain",
-                    },
-                ],
+                [M_TOPIC.name]: {
+                    "m.text": [
+                        {
+                            body: "<b>pizza</b>",
+                            mimetype: "text/html",
+                        },
+                        {
+                            body: "pizza",
+                            mimetype: "text/plain",
+                        },
+                    ],
+                },
            });
        });

        it("creates an empty event when the topic is falsey", () => {
            expect(makeTopicContent(undefined)).toEqual({
                topic: undefined,
-                [M_TOPIC.name]: [],
+                [M_TOPIC.name]: { "m.text": [] },
            });
            expect(makeTopicContent(null)).toEqual({
                topic: null,
-                [M_TOPIC.name]: [],
+                [M_TOPIC.name]: { "m.text": [] },
            });
        });
    });
@@ -225,11 +229,13 @@ describe("Topic content helpers", () => {
            expect(
                parseTopicContent({
                    topic: "pizza",
-                    [M_TOPIC.name]: [
-                        {
-                            body: "pizza",
-                        },
-                    ],
+                    [M_TOPIC.name]: {
+                        "m.text": [
+                            {
+                                body: "pizza",
+                            },
+                        ],
+                    },
                }),
            ).toEqual({
                text: "pizza",
@@ -240,12 +246,14 @@ describe("Topic content helpers", () => {
            expect(
                parseTopicContent({
                    topic: "pizza",
-                    [M_TOPIC.name]: [
-                        {
-                            body: "pizza",
-                            mimetype: "text/plain",
-                        },
-                    ],
+                    [M_TOPIC.name]: {
+                        "m.text": [
+                            {
+                                body: "pizza",
+                                mimetype: "text/plain",
+                            },
+                        ],
+                    },
                }),
            ).toEqual({
                text: "pizza",
@@ -256,12 +264,14 @@ describe("Topic content helpers", () => {
            expect(
                parseTopicContent({
                    topic: "pizza",
-                    [M_TOPIC.name]: [
-                        {
-                            body: "<b>pizza</b>",
-                            mimetype: "text/html",
-                        },
-                    ],
+                    [M_TOPIC.name]: {
+                        "m.text": [
+                            {
+                                body: "<b>pizza</b>",
+                                mimetype: "text/html",
+                            },
+                        ],
+                    },
                }),
            ).toEqual({
                text: "pizza",
@@ -279,11 +289,34 @@ describe("Topic content helpers", () => {
            });
        });

-        it("uses legacy event content when new topic key is invalid", () => {
+        // TODO delete this test and re-enable the next one after support for the invalid form is removed
+        //      https://github.com/matrix-org/matrix-js-sdk/pull/4984#pullrequestreview-3174251065
+        it("parses malformed event content with html topic", () => {
            expect(
                parseTopicContent({
                    "topic": "pizza",
-                    "m.topic": {} as any,
+                    "m.topic": [
+                        {
+                            body: "<b>pizza</b>",
+                            mimetype: "text/html",
+                        },
+                    ] as any,
+                }),
+            ).toEqual({
+                text: "pizza",
+                html: "<b>pizza</b>",
+            });
+        });
+        it.skip("uses legacy event content when new topic key is invalid", () => {
+            expect(
+                parseTopicContent({
+                    "topic": "pizza",
+                    "m.topic": [
+                        {
+                            body: "<b>pizza</b>",
+                            mimetype: "text/html",
+                        },
+                    ] as any,
                }),
            ).toEqual({
                text: "pizza",
@@ -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");
+                }
            });
        });
    });
@@ -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`] = `
 {
@@ -14,8 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { type Mocked } from "jest-mock";
-
+import type { Mocked, MockedFunction } from "jest-mock";
 import { FetchHttpApi } from "../../../src/http-api/fetch";
 import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";
 import {
@@ -43,8 +42,8 @@ describe("FetchHttpApi", () => {
    });

    it("should support aborting multiple times", () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn });
+        const fetchFn = makeMockFetchFn();
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });

        api.request(Method.Get, "/foo");
        api.request(Method.Get, "/baz");
@@ -68,13 +67,13 @@ describe("FetchHttpApi", () => {
    it("should fall back to global fetch if fetchFn not provided", () => {
        globalThis.fetch = jest.fn();
        expect(globalThis.fetch).not.toHaveBeenCalled();
-        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        api.fetch("test");
        expect(globalThis.fetch).toHaveBeenCalled();
    });

    it("should update identity server base url", () => {
-        const api = new FetchHttpApi<IHttpOpts>(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new FetchHttpApi<IHttpOpts>(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        expect(api.opts.idBaseUrl).toBeUndefined();
        api.setIdBaseUrl("https://id.foo.bar");
        expect(api.opts.idBaseUrl).toBe("https://id.foo.bar");
@@ -82,23 +81,35 @@ describe("FetchHttpApi", () => {

    describe("idServerRequest", () => {
        it("should throw if no idBaseUrl", () => {
-            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
            expect(() => api.idServerRequest(Method.Get, "/test", {}, IdentityPrefix.V2)).toThrow(
                "No identity server base URL set",
            );
        });

        it("should send params as query string for GET requests", () => {
-            const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, idBaseUrl, prefix, fetchFn });
+            const fetchFn = makeMockFetchFn();
+            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
+                baseUrl,
+                idBaseUrl,
+                prefix,
+                fetchFn,
+                onlyData: true,
+            });
            api.idServerRequest(Method.Get, "/test", { foo: "bar", via: ["a", "b"] }, IdentityPrefix.V2);
            expect(fetchFn.mock.calls[0][0].searchParams.get("foo")).toBe("bar");
            expect(fetchFn.mock.calls[0][0].searchParams.getAll("via")).toEqual(["a", "b"]);
        });

        it("should send params as body for non-GET requests", () => {
-            const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, idBaseUrl, prefix, fetchFn });
+            const fetchFn = makeMockFetchFn();
+            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
+                baseUrl,
+                idBaseUrl,
+                prefix,
+                fetchFn,
+                onlyData: true,
+            });
            const params = { foo: "bar", via: ["a", "b"] };
            api.idServerRequest(Method.Post, "/test", params, IdentityPrefix.V2);
            expect(fetchFn.mock.calls[0][0].searchParams.get("foo")).not.toBe("bar");
@@ -106,18 +117,27 @@ describe("FetchHttpApi", () => {
        });

        it("should add Authorization header if token provided", () => {
-            const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, idBaseUrl, prefix, fetchFn });
+            const fetchFn = makeMockFetchFn();
+            const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
+                baseUrl,
+                idBaseUrl,
+                prefix,
+                fetchFn,
+                onlyData: true,
+            });
            api.idServerRequest(Method.Post, "/test", {}, IdentityPrefix.V2, "token");
            expect(fetchFn.mock.calls[0][1].headers.Authorization).toBe("Bearer token");
        });
    });

-    it("should return the Response object if onlyData=false", async () => {
-        const res = { ok: true };
-        const fetchFn = jest.fn().mockResolvedValue(res);
-        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: false });
-        await expect(api.requestOtherUrl(Method.Get, "http://url")).resolves.toBe(res);
+    it("should complain if constructed without `onlyData: true`", async () => {
+        expect(
+            () =>
+                new FetchHttpApi(new TypedEventEmitter<any, any>(), {
+                    baseUrl,
+                    prefix,
+                }),
+        ).toThrow("Constructing FetchHttpApi without `onlyData=true` is no longer supported.");
    });

    it("should set an Accept header, and parse the response as JSON, by default", async () => {
@@ -165,37 +185,40 @@ describe("FetchHttpApi", () => {
    });

    it("should send token via query params if useAuthorizationHeader=false", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
            useAuthorizationHeader: false,
+            onlyData: true,
        });
        await api.authedRequest(Method.Get, "/path");
        expect(fetchFn.mock.calls[0][0].searchParams.get("access_token")).toBe("token");
    });

    it("should send token via headers by default", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
+            onlyData: true,
        });
        await api.authedRequest(Method.Get, "/path");
        expect(fetchFn.mock.calls[0][1].headers["Authorization"]).toBe("Bearer token");
    });

    it("should not send a token if not calling `authedRequest`", () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
+            onlyData: true,
        });
        api.request(Method.Get, "/path");
        expect(fetchFn.mock.calls[0][0].searchParams.get("access_token")).toBeFalsy();
@@ -203,13 +226,14 @@ describe("FetchHttpApi", () => {
    });

    it("should ensure no token is leaked out via query params if sending via headers", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
            useAuthorizationHeader: true,
+            onlyData: true,
        });
        await api.authedRequest(Method.Get, "/path", { access_token: "123" });
        expect(fetchFn.mock.calls[0][0].searchParams.get("access_token")).toBeFalsy();
@@ -217,26 +241,28 @@ describe("FetchHttpApi", () => {
    });

    it("should not override manually specified access token via query params", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
            useAuthorizationHeader: false,
+            onlyData: true,
        });
        await api.authedRequest(Method.Get, "/path", { access_token: "RealToken" });
        expect(fetchFn.mock.calls[0][0].searchParams.get("access_token")).toBe("RealToken");
    });

    it("should not override manually specified access token via header", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+        const fetchFn = makeMockFetchFn();
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            prefix,
            fetchFn,
            accessToken: "token",
            useAuthorizationHeader: true,
+            onlyData: true,
        });
        await api.authedRequest(Method.Get, "/path", undefined, undefined, {
            headers: { Authorization: "Bearer RealToken" },
@@ -245,8 +271,8 @@ describe("FetchHttpApi", () => {
    });

    it("should not override Accept header", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn });
+        const fetchFn = makeMockFetchFn();
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
        await api.authedRequest(Method.Get, "/path", undefined, undefined, {
            headers: { Accept: "text/html" },
        });
@@ -269,7 +295,7 @@ describe("FetchHttpApi", () => {
            ),
        });
        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-        const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn });
+        const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn, onlyData: true });

        await Promise.all([
            emitPromise(emitter, HttpApiEvent.NoConsent),
@@ -279,9 +305,9 @@ describe("FetchHttpApi", () => {

    describe("authedRequest", () => {
        it("should not include token if unset", async () => {
-            const fetchFn = jest.fn().mockResolvedValue({ ok: true });
+            const fetchFn = makeMockFetchFn();
            const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-            const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn });
+            const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn, onlyData: true });
            await api.authedRequest(Method.Post, "/account/password");
            expect(fetchFn.mock.calls[0][1].headers.Authorization).toBeUndefined();
        });
@@ -310,6 +336,7 @@ describe("FetchHttpApi", () => {
                const okayResponse = {
                    ok: true,
                    status: 200,
+                    json: jest.fn().mockResolvedValue({ x: 1 }),
                };

                describe("without a tokenRefreshFunction", () => {
@@ -317,7 +344,14 @@ describe("FetchHttpApi", () => {
                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
                        jest.spyOn(emitter, "emit");
-                        const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn, accessToken, refreshToken });
+                        const api = new FetchHttpApi(emitter, {
+                            baseUrl,
+                            prefix,
+                            fetchFn,
+                            accessToken,
+                            refreshToken,
+                            onlyData: true,
+                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
                            unknownTokenErr,
                        );
@@ -339,8 +373,9 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            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);
@@ -360,8 +395,9 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            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);
@@ -388,11 +424,12 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            refreshToken,
+                            onlyData: true,
                        });
                        const result = await api.authedRequest(Method.Post, "/account/password", undefined, undefined, {
                            headers: {},
                        });
-                        expect(result).toEqual(okayResponse);
+                        expect(result).toEqual({ x: 1 });
                        expect(tokenRefreshFunction).toHaveBeenCalledWith(refreshToken);

                        expect(fetchFn).toHaveBeenCalledTimes(2);
@@ -431,6 +468,7 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            refreshToken,
+                            onlyData: true,
                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
                            unknownTokenErr,
@@ -486,6 +524,7 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            refreshToken,
+                            onlyData: true,
                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
                            unknownTokenErr,
@@ -506,7 +545,7 @@ describe("FetchHttpApi", () => {
        const makeApi = (thisBaseUrl = baseUrl): FetchHttpApi<any> => {
            const fetchFn = jest.fn();
            const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-            return new FetchHttpApi(emitter, { baseUrl: thisBaseUrl, prefix, fetchFn });
+            return new FetchHttpApi(emitter, { baseUrl: thisBaseUrl, prefix, fetchFn, onlyData: true });
        };

        type TestParams = {
@@ -559,7 +598,13 @@ describe("FetchHttpApi", () => {
            const makeApiWithExtraParams = (extraParams: QueryDict): FetchHttpApi<any> => {
                const fetchFn = jest.fn();
                const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                return new FetchHttpApi(emitter, { baseUrl: localBaseUrl, prefix, fetchFn, extraParams });
+                return new FetchHttpApi(emitter, {
+                    baseUrl: localBaseUrl,
+                    prefix,
+                    fetchFn,
+                    onlyData: true,
+                    extraParams,
+                });
            };

            const userId = "@rsb-tbg:localhost";
@@ -612,7 +657,7 @@ describe("FetchHttpApi", () => {
            it("should work when extraParams is undefined", () => {
                const fetchFn = jest.fn();
                const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                const api = new FetchHttpApi(emitter, { baseUrl: localBaseUrl, prefix, fetchFn });
+                const api = new FetchHttpApi(emitter, { baseUrl: localBaseUrl, prefix, fetchFn, onlyData: true });

                const queryParams = { userId: "123" };
                const result = api.getUrl("/test", queryParams);
@@ -645,10 +690,11 @@ describe("FetchHttpApi", () => {
            prefix,
            fetchFn,
            logger: mockLogger,
+            onlyData: true,
        });
        const prom = api.requestOtherUrl(Method.Get, "https://server:8448/some/path?query=param#fragment");
        jest.advanceTimersByTime(1234);
-        responseResolvers.resolve({ ok: true, status: 200, text: () => Promise.resolve("RESPONSE") } as Response);
+        responseResolvers.resolve({ ok: true, status: 200, json: () => Promise.resolve("RESPONSE") } as Response);
        await prom;
        expect(mockLogger.debug).not.toHaveBeenCalledWith("fragment");
        expect(mockLogger.debug).not.toHaveBeenCalledWith("query");
@@ -691,6 +737,7 @@ describe("FetchHttpApi", () => {
            tokenRefreshFunction,
            accessToken: "ACCESS_TOKEN",
            refreshToken: "REFRESH_TOKEN",
+            onlyData: true,
        });

        const prom1 = api.authedRequest(Method.Get, "/path1");
@@ -746,6 +793,7 @@ describe("FetchHttpApi", () => {
            tokenRefreshFunction,
            accessToken: "ACCESS_TOKEN",
            refreshToken: "REFRESH_TOKEN",
+            onlyData: true,
        });

        const prom1 = api.authedRequest(Method.Get, "/path1");
@@ -783,3 +831,7 @@ describe("FetchHttpApi", () => {
        expect(api.opts.refreshToken).toBe("NEW_REFRESH_TOKEN");
    });
 });
+
+function makeMockFetchFn(): MockedFunction<any> {
+    return jest.fn().mockResolvedValue({ ok: true, json: jest.fn().mockResolvedValue({}) });
+}
@@ -62,7 +62,7 @@ describe("MatrixHttpApi", () => {
    it("should fall back to `fetch` where xhr is unavailable", async () => {
        globalThis.XMLHttpRequest = undefined!;
        const fetchFn = jest.fn().mockResolvedValue({ ok: true, json: jest.fn().mockResolvedValue({}) });
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
        upload = api.uploadContent({} as File);
        await upload;
        expect(fetchFn).toHaveBeenCalled();
@@ -70,7 +70,7 @@ describe("MatrixHttpApi", () => {

    it("should prefer xhr where available", () => {
        const fetchFn = jest.fn().mockResolvedValue({ ok: true });
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
        upload = api.uploadContent({} as File);
        expect(fetchFn).not.toHaveBeenCalled();
        expect(xhr.open).toHaveBeenCalled();
@@ -82,6 +82,7 @@ describe("MatrixHttpApi", () => {
            prefix,
            accessToken: "token",
            useAuthorizationHeader: false,
+            onlyData: true,
        });
        upload = api.uploadContent({} as File);
        expect(xhr.open).toHaveBeenCalledWith(
@@ -96,6 +97,7 @@ describe("MatrixHttpApi", () => {
            baseUrl,
            prefix,
            accessToken: "token",
+            onlyData: true,
        });
        upload = api.uploadContent({} as File);
        expect(xhr.open).toHaveBeenCalledWith(Method.Post, baseUrl.toLowerCase() + "/_matrix/media/v3/upload");
@@ -103,7 +105,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should include filename by default", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File, { name: "name" });
        expect(xhr.open).toHaveBeenCalledWith(
            Method.Post,
@@ -112,13 +114,13 @@ describe("MatrixHttpApi", () => {
    });

    it("should allow not sending the filename", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File, { name: "name", includeFilename: false });
        expect(xhr.open).toHaveBeenCalledWith(Method.Post, baseUrl.toLowerCase() + "/_matrix/media/v3/upload");
    });

    it("should abort xhr when the upload is aborted", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);
        api.cancelUpload(upload);
        expect(xhr.abort).toHaveBeenCalled();
@@ -126,7 +128,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should timeout if no progress in 30s", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);
        jest.advanceTimersByTime(25000);
        // @ts-ignore
@@ -138,7 +140,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should call progressHandler", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        const progressHandler = jest.fn();
        upload = api.uploadContent({} as File, { progressHandler });
        const progressEvent = new Event("progress") as ProgressEvent;
@@ -154,7 +156,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should error when no response body", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);

        xhr.readyState = DONE;
@@ -167,7 +169,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should error on a 400-code", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);

        xhr.readyState = DONE;
@@ -184,7 +186,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should return response on successful upload", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);

        xhr.readyState = DONE;
@@ -198,14 +200,14 @@ describe("MatrixHttpApi", () => {
    });

    it("should abort xhr when calling `cancelUpload`", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);
        expect(api.cancelUpload(upload)).toBeTruthy();
        expect(xhr.abort).toHaveBeenCalled();
    });

    it("should return false when `cancelUpload` is called but unsuccessful", async () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);

        xhr.readyState = DONE;
@@ -220,7 +222,7 @@ describe("MatrixHttpApi", () => {
    });

    it("should return active uploads in `getCurrentUploads`", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        upload = api.uploadContent({} as File);
        expect(api.getCurrentUploads().find((u) => u.promise === upload)).toBeTruthy();
        api.cancelUpload(upload);
@@ -228,7 +230,12 @@ describe("MatrixHttpApi", () => {
    });

    it("should return expected object from `getContentUri`", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, accessToken: "token" });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), {
+            baseUrl,
+            prefix,
+            accessToken: "token",
+            onlyData: true,
+        });
        expect(api.getContentUri()).toMatchSnapshot();
    });
 });
@@ -21,6 +21,8 @@ import {
    ConnectionError,
    HTTPError,
    MatrixError,
+    MatrixSafetyError,
+    MatrixSafetyErrorCode,
    parseErrorResponse,
    retryNetworkOperation,
    timeoutSignal,
@@ -185,6 +187,35 @@ describe("parseErrorResponse", () => {
            ),
        );
    });
+    it.each([
+        {
+            errcode: MatrixSafetyErrorCode.name,
+            error: "Spammy",
+        },
+        {
+            errcode: MatrixSafetyErrorCode.name,
+            error: "Spammy",
+            expiry: 5000,
+        },
+        {
+            errcode: MatrixSafetyErrorCode.name,
+            error: "Spammy",
+            harms: ["m.spam", "org.example.additional-harm"],
+            expiry: 5000,
+        },
+    ])("should resolve MatrixSafetyErrors from fetch", (errContent) => {
+        headers.set("Content-Type", "application/json");
+        const value = parseErrorResponse(
+            {
+                headers,
+                status: 400,
+            } as Response,
+            JSON.stringify(errContent),
+        ) as MatrixSafetyError;
+        expect(value).toBeInstanceOf(MatrixSafetyError);
+        expect(value.harms.size).toEqual(errContent.harms?.length ?? 0);
+        expect(value.expiry?.getTime()).toEqual(errContent.expiry);
+    });

    describe("with HTTP headers", () => {
        function addHeaders(headers: Headers) {
@@ -84,6 +84,7 @@ import { mockOpenIdConfiguration } from "../test-utils/oidc.ts";
 import { type CryptoBackend } from "../../src/common-crypto/CryptoBackend";
 import { SyncResponder } from "../test-utils/SyncResponder.ts";
 import { mockInitialApiRequests } from "../test-utils/mockEndpoints.ts";
+import { type Transport } from "src/matrixrtc/index.ts";

 jest.useFakeTimers();

@@ -801,6 +802,10 @@ 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 +1058,193 @@ 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);
        });
    });

@@ -2366,6 +2530,61 @@ describe("MatrixClient", function () {
        });
    });

+    describe("disableVoip option", () => {
+        const baseUrl = "https://alice-server.com";
+        const userId = "@alice:bar";
+        const accessToken = "sometoken";
+
+        beforeEach(() => {
+            mocked(supportsMatrixCall).mockReturnValue(true);
+        });
+
+        afterAll(() => {
+            mocked(supportsMatrixCall).mockReset();
+        });
+
+        it("should not call /voip/turnServer when disableVoip = true", () => {
+            fetchMock.getOnce(`${baseUrl}/_matrix/client/unstable/voip/turnServer`, 200);
+
+            const client = createClient({
+                baseUrl,
+                accessToken,
+                userId,
+                disableVoip: true,
+            });
+
+            // Only check createCall / supportsVoip, avoid startClient
+            expect(client.createCall("!roomId:example.com")).toBeNull();
+            expect(client.supportsVoip?.()).toBe(false);
+        });
+
+        it("should call /voip/turnServer when disableVoip is not set", () => {
+            fetchMock.getOnce(`${baseUrl}/_matrix/client/unstable/voip/turnServer`, {
+                uris: ["turn:turn.example.org"],
+            });
+
+            createClient({
+                baseUrl,
+                accessToken,
+                userId,
+            });
+
+            // The call will trigger the request if VoIP is supported
+            expect(fetchMock.called(`${baseUrl}/_matrix/client/unstable/voip/turnServer`)).toBe(false);
+        });
+
+        it("should return null from createCall when disableVoip = true", () => {
+            const client = createClient({
+                baseUrl,
+                accessToken,
+                userId,
+                disableVoip: true,
+            });
+
+            expect(client.createCall("!roomId:example.com")).toBeNull();
+        });
+    });
+
    describe("support for ignoring invites", () => {
        beforeEach(() => {
            // Mockup `getAccountData`/`setAccountData`.
@@ -2998,6 +3217,8 @@ describe("MatrixClient", function () {
                    replacedByDynamicPredecessor2,
                    room2,
                ];
+                client.store.getRoom = (roomId: string) =>
+                    client.store.getRooms().find((r) => r.roomId === roomId) || null;
                room1.addLiveEvents(
                    [
                        roomCreateEvent(room1.roomId, replacedByCreate1.roomId),
@@ -3036,6 +3257,7 @@ describe("MatrixClient", function () {
                    replacedByDynamicPredecessor2,
                };
            }
+
            it("Returns an empty list if there are no rooms", () => {
                client.store = new StubStore();
                client.store.getRooms = () => [];
@@ -3062,6 +3284,8 @@ describe("MatrixClient", function () {
                const room2 = new Room("room2", client, "@daryl:alexandria.example.com");
                client.store = new StubStore();
                client.store.getRooms = () => [room1, replacedRoom1, replacedRoom2, room2];
+                client.store.getRoom = (roomId: string) =>
+                    client.store.getRooms().find((r) => r.roomId === roomId) || null;
                room1.addLiveEvents([roomCreateEvent(room1.roomId, replacedRoom1.roomId)], { addToState: true });
                room2.addLiveEvents([roomCreateEvent(room2.roomId, replacedRoom2.roomId)], { addToState: true });
                replacedRoom1.addLiveEvents([tombstoneEvent(room1.roomId, replacedRoom1.roomId)], { addToState: true });
@@ -3127,6 +3351,24 @@ describe("MatrixClient", function () {
                expect(rooms).toContain(room1);
                expect(rooms).toContain(room2);
            });
+
+            it("should ignore room replacements which are not reciprocated by the predecessor", () => {
+                const room1 = new Room("room1", client, "@carol:alexandria.example.com");
+                // Room 2 claims to replace room 1 but room 1 does not agree
+                const room2 = new Room("replacedRoom1", client, "@daryl:alexandria.example.com");
+
+                client.store = new StubStore();
+                client.store.getRooms = () => [room1, room2];
+                client.store.getRoom = (roomId: string) =>
+                    client.store.getRooms().find((r) => r.roomId === roomId) || null;
+
+                room2.addLiveEvents([roomCreateEvent(room2.roomId, room1.roomId)], { addToState: true });
+
+                // When we ask for the visible rooms
+                const rooms = client.getVisibleRooms();
+                expect(rooms).toContain(room1);
+                expect(rooms).toContain(room2);
+            });
        });

        describe("getRoomUpgradeHistory", () => {
@@ -3597,24 +3839,6 @@ describe("MatrixClient", function () {
        });
    });

-    describe("getAuthIssuer", () => {
-        it("should use unstable prefix", async () => {
-            httpLookups = [
-                {
-                    method: "GET",
-                    path: `/auth_issuer`,
-                    data: {
-                        issuer: "https://issuer/",
-                    },
-                    prefix: "/_matrix/client/unstable/org.matrix.msc2965",
-                },
-            ];
-
-            await expect(client.getAuthIssuer()).resolves.toEqual({ issuer: "https://issuer/" });
-            expect(httpLookups.length).toEqual(0);
-        });
-    });
-
    describe("getAuthMetadata", () => {
        beforeEach(() => {
            fetchMock.mockReset();
@@ -3712,4 +3936,23 @@ describe("MatrixClient", function () {
            expect(lookupResult[0]).toEqual({ address: "bob@email.dummy", mxid: "@bob:homeserver.dummy" });
        });
    });
+
+    describe("_unstable_getRTCTransports", () => {
+        it("makes a well-formed request", async () => {
+            httpLookups = [
+                {
+                    method: "GET",
+                    path: `/rtc/transports`,
+                    data: { rtc_transports: [{ type: "livekit", extra_field: "foobar" }] satisfies Transport[] },
+                    prefix: "/_matrix/client/unstable/org.matrix.msc4143",
+                },
+            ];
+            expect(await client._unstable_getRTCTransports()).toEqual([
+                {
+                    type: "livekit",
+                    extra_field: "foobar",
+                },
+            ]);
+        });
+    });
 });
@@ -19,6 +19,7 @@ import {
    CallMembership,
    type SessionMembershipData,
    DEFAULT_EXPIRE_DURATION,
+    type RtcMembershipData,
 } from "../../../src/matrixrtc/CallMembership";
 import { membershipTemplate } from "./mocks";

@@ -26,9 +27,17 @@ function makeMockEvent(originTs = 0): MatrixEvent {
    return {
        getTs: jest.fn().mockReturnValue(originTs),
        getSender: jest.fn().mockReturnValue("@alice:example.org"),
+        getId: jest.fn().mockReturnValue("$eventid"),
+        getContent: jest.fn().mockReturnValue({}),
    } as unknown as MatrixEvent;
 }

+function createCallMembership(ev: MatrixEvent, content: unknown): CallMembership {
+    (ev.getContent as jest.Mock).mockReturnValue(content);
+    const data = CallMembership.membershipDataFromMatrixEvent(ev);
+    return new CallMembership(ev, data, "xx");
+}
+
 describe("CallMembership", () => {
    describe("SessionMembershipData", () => {
        beforeEach(() => {
@@ -40,39 +49,40 @@ describe("CallMembership", () => {
        });

        const membershipTemplate: SessionMembershipData = {
-            call_id: "",
-            scope: "m.room",
-            application: "m.call",
-            device_id: "AAAAAAA",
-            focus_active: { type: "livekit" },
-            foci_preferred: [{ type: "livekit" }],
+            "call_id": "",
+            "scope": "m.room",
+            "application": "m.call",
+            "device_id": "AAAAAAA",
+            "focus_active": { type: "livekit", focus_selection: "oldest_membership" },
+            "foci_preferred": [{ type: "livekit" }],
+            "m.call.intent": "voice",
        };

        it("rejects membership with no device_id", () => {
            expect(() => {
-                new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { device_id: undefined }));
+                createCallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { device_id: undefined }));
            }).toThrow();
        });

        it("rejects membership with no call_id", () => {
            expect(() => {
-                new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { call_id: undefined }));
+                createCallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { call_id: undefined }));
            }).toThrow();
        });

        it("allow membership with no scope", () => {
            expect(() => {
-                new CallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { scope: undefined }));
+                createCallMembership(makeMockEvent(), Object.assign({}, membershipTemplate, { scope: undefined }));
            }).not.toThrow();
        });

        it("uses event timestamp if no created_ts", () => {
-            const membership = new CallMembership(makeMockEvent(12345), membershipTemplate);
+            const membership = createCallMembership(makeMockEvent(12345), membershipTemplate);
            expect(membership.createdTs()).toEqual(12345);
        });

        it("uses created_ts if present", () => {
-            const membership = new CallMembership(
+            const membership = createCallMembership(
                makeMockEvent(12345),
                Object.assign({}, membershipTemplate, { created_ts: 67890 }),
            );
@@ -82,23 +92,283 @@ describe("CallMembership", () => {
        it("considers memberships unexpired if local age low enough", () => {
            const fakeEvent = makeMockEvent(1000);
            fakeEvent.getTs = jest.fn().mockReturnValue(Date.now() - (DEFAULT_EXPIRE_DURATION - 1));
-            expect(new CallMembership(fakeEvent, membershipTemplate).isExpired()).toEqual(false);
+            expect(createCallMembership(fakeEvent, membershipTemplate).isExpired()).toEqual(false);
        });

        it("considers memberships expired if local age large enough", () => {
            const fakeEvent = makeMockEvent(1000);
            fakeEvent.getTs = jest.fn().mockReturnValue(Date.now() - (DEFAULT_EXPIRE_DURATION + 1));
-            expect(new CallMembership(fakeEvent, membershipTemplate).isExpired()).toEqual(true);
+            expect(createCallMembership(fakeEvent, membershipTemplate).isExpired()).toEqual(true);
        });

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

@@ -109,7 +379,7 @@ describe("CallMembership", () => {
        beforeEach(() => {
            // server origin timestamp for this event is 1000
            fakeEvent = makeMockEvent(1000);
-            membership = new CallMembership(fakeEvent!, membershipTemplate);
+            membership = createCallMembership(fakeEvent!, membershipTemplate);

            jest.useFakeTimers();
        });
@@ -14,47 +14,51 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { isLivekitFocus, isLivekitFocusActive, isLivekitFocusConfig } from "../../../src/matrixrtc/LivekitFocus";
+import {
+    isLivekitTransport,
+    isLivekitFocusSelection,
+    isLivekitTransportConfig,
+} from "../../../src/matrixrtc/LivekitTransport";

 describe("LivekitFocus", () => {
    it("isLivekitFocus", () => {
        expect(
-            isLivekitFocus({
+            isLivekitTransport({
                type: "livekit",
                livekit_service_url: "http://test.com",
                livekit_alias: "test",
            }),
        ).toBeTruthy();
-        expect(isLivekitFocus({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitTransport({ type: "livekit" })).toBeFalsy();
        expect(
-            isLivekitFocus({ type: "not-livekit", livekit_service_url: "http://test.com", livekit_alias: "test" }),
+            isLivekitTransport({ type: "not-livekit", livekit_service_url: "http://test.com", livekit_alias: "test" }),
        ).toBeFalsy();
        expect(
-            isLivekitFocus({ type: "livekit", other_service_url: "http://test.com", livekit_alias: "test" }),
+            isLivekitTransport({ type: "livekit", other_service_url: "http://test.com", livekit_alias: "test" }),
        ).toBeFalsy();
        expect(
-            isLivekitFocus({ type: "livekit", livekit_service_url: "http://test.com", other_alias: "test" }),
+            isLivekitTransport({ type: "livekit", livekit_service_url: "http://test.com", other_alias: "test" }),
        ).toBeFalsy();
    });
    it("isLivekitFocusActive", () => {
        expect(
-            isLivekitFocusActive({
+            isLivekitFocusSelection({
                type: "livekit",
                focus_selection: "oldest_membership",
            }),
        ).toBeTruthy();
-        expect(isLivekitFocusActive({ type: "livekit" })).toBeFalsy();
-        expect(isLivekitFocusActive({ type: "not-livekit", focus_selection: "oldest_membership" })).toBeFalsy();
+        expect(isLivekitFocusSelection({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitFocusSelection({ type: "not-livekit", focus_selection: "oldest_membership" })).toBeFalsy();
    });
    it("isLivekitFocusConfig", () => {
        expect(
-            isLivekitFocusConfig({
+            isLivekitTransportConfig({
                type: "livekit",
                livekit_service_url: "http://test.com",
            }),
        ).toBeTruthy();
-        expect(isLivekitFocusConfig({ type: "livekit" })).toBeFalsy();
-        expect(isLivekitFocusConfig({ type: "not-livekit", livekit_service_url: "http://test.com" })).toBeFalsy();
-        expect(isLivekitFocusConfig({ type: "livekit", other_service_url: "oldest_membership" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "livekit" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "not-livekit", livekit_service_url: "http://test.com" })).toBeFalsy();
+        expect(isLivekitTransportConfig({ type: "livekit", other_service_url: "oldest_membership" })).toBeFalsy();
    });
 });
@@ -14,54 +14,149 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { ClientEvent, EventTimeline, MatrixClient } from "../../../src";
-import { RoomStateEvent } from "../../../src/models/room-state";
-import { MatrixRTCSessionManagerEvents } from "../../../src/matrixrtc/MatrixRTCSessionManager";
-import { makeMockRoom, membershipTemplate, mockRoomState } from "./mocks";
+import { ClientEvent, EventTimeline, MatrixClient, type Room, RoomStateEvent } from "../../../src";
+import { MatrixRTCSessionManager, MatrixRTCSessionManagerEvents } from "../../../src/matrixrtc";
+import { makeMockRoom, type MembershipData, membershipTemplate, mockRoomState, mockRTCEvent } from "./mocks";
+import { logger } from "../../../src/logger";
+import { flushPromises } from "../../test-utils/flushPromises";

-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();
-    });
+        async function sendLeaveMembership(room: Room, membershipData: MembershipData[]): Promise<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));
+            }
+            await flushPromises();
+        }

-    afterEach(() => {
-        client.stopClient();
-        client.matrixRTC.stop();
-    });
+        beforeEach(() => {
+            client = new MatrixClient({ baseUrl: "base_url" });
+            client.matrixRTC.start();
+        });

-    it("Fires event when session starts", () => {
-        const onStarted = jest.fn();
-        client.matrixRTC.on(MatrixRTCSessionManagerEvents.SessionStarted, onStarted);
+        afterEach(() => {
+            client.stopClient();
+            client.matrixRTC.stop();
+        });

-        try {
-            const room1 = makeMockRoom([membershipTemplate]);
+        it("Fires event when session starts", async () => {
+            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);
+                await flushPromises();
+                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", async () => {
+            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);
+            await flushPromises();
+            await sendLeaveMembership(room1, membershipData);
+
+            expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
+        });
+
+        it("Fires correctly with custom sessionDescription", async () => {
+            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",
+            });
+
+            // 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);
+
+            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);
+                await flushPromises();
+                expect(onStarted).not.toHaveBeenCalled();
+                onStarted.mockClear();
+
+                // Create a session for applicaation m.notCall. We expect this call to be tracked because it has a call_id
+                const room2MembershipData: MembershipData[] = [
+                    { ...membershipTemplate, application: "m.notCall", call_id: "test" },
+                ];
+                const room2 = makeMockRoom(room2MembershipData, eventKind === "sticky");
+                jest.spyOn(client, "getRooms").mockReturnValue([room1, room2]);
+                client.emit(ClientEvent.Room, room2);
+                await flushPromises();
+                expect(onStarted).toHaveBeenCalled();
+                onStarted.mockClear();
+
+                // Stop room1's RTC session. Tracked.
+                jest.spyOn(client, "getRoom").mockReturnValue(room2);
+                await sendLeaveMembership(room2, room2MembershipData);
+                expect(onEnded).toHaveBeenCalled();
+                onEnded.mockClear();
+
+                // Stop room1's RTC session. Not tracked.
+                jest.spyOn(client, "getRoom").mockReturnValue(room1);
+                await 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", async () => {
+            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]);
+            jest.spyOn(client, "getRoom").mockReturnValue(room1);

            client.emit(ClientEvent.Room, room1);
-            expect(onStarted).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
-        } 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);
+            await 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("")[0];
-        client.emit(RoomStateEvent.Events, membEvent, roomState, null);
-
-        expect(onEnded).toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
-    });
-});
+            expect(onEnded).not.toHaveBeenCalledWith(room1.roomId, client.matrixRTC.getActiveRoomSession(room1));
+        });
+    },
+);
@@ -16,17 +16,24 @@ limitations under the License.

 import { type MockedFunction, type Mock } from "jest-mock";

-import { EventType, HTTPError, MatrixError, UnsupportedDelayedEventsEndpointError, type Room } from "../../../src";
+import {
+    type EmptyObject,
+    EventType,
+    HTTPError,
+    MatrixError,
+    UnsupportedDelayedEventsEndpointError,
+    type Room,
+    MAX_STICKY_DURATION_MS,
+} from "../../../src";
 import {
    MembershipManagerEvent,
    Status,
-    type Focus,
-    type LivekitFocusActive,
+    type Transport,
    type SessionMembershipData,
+    type LivekitFocusSelection,
 } from "../../../src/matrixrtc";
 import { makeMockClient, makeMockRoom, membershipTemplate, mockCallMembership, type MockClient } from "./mocks";
-import { logger } from "../../../src/logger.ts";
-import { MembershipManager } from "../../../src/matrixrtc/MembershipManager.ts";
+import { MembershipManager, StickyEventMembershipManager } from "../../../src/matrixrtc/MembershipManager.ts";

 /**
 * Create a promise that will resolve once a mocked method is called.
@@ -64,14 +71,16 @@ function createAsyncHandle<T>(method: MockedFunction<any>) {
    return { reject, resolve };
 }

+const callSession = { id: "", application: "m.call" };
+
 describe("MembershipManager", () => {
    let client: MockClient;
    let room: Room;
-    const focusActive: LivekitFocusActive = {
+    const focusActive: LivekitFocusSelection = {
        focus_selection: "oldest_membership",
        type: "livekit",
    };
-    const focus: Focus = {
+    const focus: Transport = {
        type: "livekit",
        livekit_service_url: "https://active.url",
        livekit_alias: "!active:active.url",
@@ -85,7 +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(() => {
@@ -95,12 +109,12 @@ describe("MembershipManager", () => {

    describe("isActivated()", () => {
        it("defaults to false", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            expect(manager.isActivated()).toEqual(false);
        });

        it("returns true after join()", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([]);
            expect(manager.isActivated()).toEqual(true);
        });
@@ -111,11 +125,13 @@ 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, () => undefined);
-                memberManager.join([focus], focusActive);
+                const memberManager = new MembershipManager(undefined, room, client, callSession);
+                memberManager.join([focus], undefined);
                // expects
                await waitForMockCall(client.sendStateEvent, Promise.resolve({ event_id: "id" }));
                expect(client.sendStateEvent).toHaveBeenCalledWith(
@@ -127,32 +143,33 @@ describe("MembershipManager", () => {
                        device_id: "AAAAAAA",
                        expires: 14400000,
                        foci_preferred: [focus],
+                        membershipID: "@alice:example.org:AAAAAAA",
                        focus_active: focusActive,
                        scope: "m.room",
                    },
-                    "_@alice:example.org_AAAAAAA",
+                    "_@alice:example.org_AAAAAAA_m.call",
                );
-                updateDelayedEventHandle.resolve?.();
+                restartScheduledDelayedEventHandle.resolve?.();
                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
                    room.roomId,
                    { delay: 8000 },
                    "org.matrix.msc3401.call.member",
                    {},
-                    "_@alice:example.org_AAAAAAA",
+                    "_@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, () => undefined);
+                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)
@@ -168,7 +185,7 @@ 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({
@@ -189,7 +206,7 @@ describe("MembershipManager", () => {
                        });
                    });

-                    const userStateKey = `${!useOwnedStateEvents ? "_" : ""}@alice:example.org_AAAAAAA`;
+                    const userStateKey = `${!useOwnedStateEvents ? "_" : ""}@alice:example.org_AAAAAAA_m.call`;
                    // preparing the delayed disconnect should handle ratelimiting
                    const sendDelayedStateAttempt = new Promise<void>((resolve) => {
                        const error = new MatrixError({ errcode: "M_LIMIT_EXCEEDED" });
@@ -219,9 +236,9 @@ describe("MembershipManager", () => {
                        },
                        room,
                        client,
-                        () => undefined,
+                        callSession,
                    );
-                    manager.join([focus], focusActive);
+                    manager.join([focus]);

                    await sendDelayedStateExceedAttempt.then(); // needed to resolve after the send attempt catches
                    await sendDelayedStateAttempt;
@@ -247,6 +264,7 @@ describe("MembershipManager", () => {
                            expires: 14400000,
                            device_id: "AAAAAAA",
                            foci_preferred: [focus],
+                            membershipID: "@alice:example.org:AAAAAAA",
                            focus_active: focusActive,
                        } satisfies SessionMembershipData,
                        userStateKey,
@@ -254,13 +272,13 @@ 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 () => {
@@ -276,8 +294,8 @@ describe("MembershipManager", () => {
        describe("delayed leave event", () => {
            it("does not try again to schedule a delayed leave event if not supported", () => {
                const delayedHandle = createAsyncHandle(client._unstable_sendDelayedStateEvent as Mock);
-                const manager = new MembershipManager({}, room, client, () => undefined);
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({}, room, client, callSession);
+                manager.join([focus]);
                delayedHandle.reject?.(
                    new UnsupportedDelayedEventsEndpointError(
                        "Server does not support the delayed events API",
@@ -288,26 +306,21 @@ describe("MembershipManager", () => {
            });
            it("does try to schedule a delayed leave event again if rate limited", async () => {
                const delayedHandle = createAsyncHandle(client._unstable_sendDelayedStateEvent as Mock);
-                const manager = new MembershipManager({}, room, client, () => undefined);
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({}, room, client, callSession);
+                manager.join([focus]);
                delayedHandle.reject?.(new HTTPError("rate limited", 429, undefined));
                await jest.advanceTimersByTimeAsync(5000);
                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(2);
            });
            it("uses delayedLeaveEventDelayMs from config", () => {
-                const manager = new MembershipManager(
-                    { delayedLeaveEventDelayMs: 123456 },
-                    room,
-                    client,
-                    () => undefined,
-                );
-                manager.join([focus], focusActive);
+                const manager = new MembershipManager({ delayedLeaveEventDelayMs: 123456 }, room, client, callSession);
+                manager.join([focus]);
                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledWith(
                    room.roomId,
                    { delay: 123456 },
                    "org.matrix.msc3401.call.member",
                    {},
-                    "_@alice:example.org_AAAAAAA",
+                    "_@alice:example.org_AAAAAAA_m.call",
                );
            });
        });
@@ -318,10 +331,11 @@ describe("MembershipManager", () => {
                { delayedLeaveEventRestartMs: RESTART_DELAY },
                room,
                client,
-                () => undefined,
+
+                callSession,
            );
            // Join with the membership manager
-            manager.join([focus], focusActive);
+            manager.join([focus]);
            expect(manager.status).toBe(Status.Connecting);
            // Let the scheduler run one iteration so that we can send the join state event
            await jest.runOnlyPendingTimersAsync();
@@ -336,7 +350,7 @@ 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" }),
            );

@@ -351,9 +365,15 @@ describe("MembershipManager", () => {
        });

        it("uses membershipEventExpiryMs from config", async () => {
-            const manager = new MembershipManager({ membershipEventExpiryMs: 1234567 }, room, client, () => undefined);
+            const manager = new MembershipManager(
+                { membershipEventExpiryMs: 1234567 },
+                room,
+                client,

-            manager.join([focus], focusActive);
+                callSession,
+            );
+
+            manager.join([focus]);
            await waitForMockCall(client.sendStateEvent);
            expect(client.sendStateEvent).toHaveBeenCalledWith(
                room.roomId,
@@ -365,21 +385,22 @@ describe("MembershipManager", () => {
                    device_id: "AAAAAAA",
                    expires: 1234567,
                    foci_preferred: [focus],
+                    membershipID: "@alice:example.org:AAAAAAA",
                    focus_active: {
                        focus_selection: "oldest_membership",
                        type: "livekit",
                    },
                },
-                "_@alice:example.org_AAAAAAA",
+                "_@alice:example.org_AAAAAAA_m.call",
            );
        });

        it("does nothing if join called when already joined", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
            await waitForMockCall(client.sendStateEvent);
            expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
-            manager.join([focus], focusActive);
+            manager.join([focus]);
            expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
        });
    });
@@ -387,97 +408,59 @@ describe("MembershipManager", () => {
    describe("leave()", () => {
        // TODO add rate limit cases.
        it("resolves delayed leave event when leave is called", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
            await jest.advanceTimersByTimeAsync(1);
            await manager.leave();
-            expect(client._unstable_updateDelayedEvent).toHaveBeenLastCalledWith("id", "send");
+            expect(client._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, () => undefined);
-            manager.join([focus], focusActive);
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([focus]);
            await jest.advanceTimersByTimeAsync(1);
-            (client._unstable_updateDelayedEvent as Mock<any>).mockRejectedValue("unknown");
+            (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",
                {},
-                "_@alice:example.org_AAAAAAA",
+                "_@alice:example.org_AAAAAAA_m.call",
            );
        });
        it("does nothing if not joined", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            expect(async () => await manager.leave()).not.toThrow();
            expect(client._unstable_sendDelayedStateEvent).not.toHaveBeenCalled();
            expect(client.sendStateEvent).not.toHaveBeenCalled();
        });
    });

-    describe("getsActiveFocus", () => {
-        it("gets the correct active focus with oldest_membership", () => {
-            const getOldestMembership = jest.fn();
-            const manager = new MembershipManager({}, room, client, getOldestMembership);
-            // Before joining the active focus should be undefined (see FocusInUse on MatrixRTCSession)
-            expect(manager.getActiveFocus()).toBe(undefined);
-            manager.join([focus], focusActive);
-            // After joining we want our own focus to be the one we select.
-            getOldestMembership.mockReturnValue(
-                mockCallMembership(
-                    {
-                        ...membershipTemplate,
-                        foci_preferred: [
-                            {
-                                livekit_alias: "!active:active.url",
-                                livekit_service_url: "https://active.url",
-                                type: "livekit",
-                            },
-                        ],
-                        user_id: client.getUserId()!,
-                        device_id: client.getDeviceId()!,
-                        created_ts: 1000,
-                    },
-                    room.roomId,
-                ),
-            );
-            expect(manager.getActiveFocus()).toStrictEqual(focus);
-            getOldestMembership.mockReturnValue(
-                mockCallMembership(
-                    Object.assign({}, membershipTemplate, { device_id: "old", created_ts: 1000 }),
-                    room.roomId,
-                ),
-            );
-            // If there is an older member we use its focus.
-            expect(manager.getActiveFocus()).toBe(membershipTemplate.foci_preferred[0]);
-        });
-
-        it("does not provide focus if the selection method is unknown", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
-            manager.join([focus], Object.assign(focusActive, { type: "unknown_type" }));
-            expect(manager.getActiveFocus()).toBe(undefined);
-        });
-    });
-
    describe("onRTCSessionMemberUpdate()", () => {
        it("does nothing if not joined", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            await manager.onRTCSessionMemberUpdate([mockCallMembership(membershipTemplate, room.roomId)]);
            await jest.advanceTimersToNextTimerAsync();
            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, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive);
            await jest.advanceTimersByTimeAsync(1);
            const myMembership = (client.sendStateEvent as Mock).mock.calls[0][2];
            // 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([
@@ -493,14 +476,17 @@ 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, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive);
            await jest.advanceTimersByTimeAsync(1);
            // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
            (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:
@@ -509,19 +495,19 @@ 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 () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive);
            await jest.advanceTimersByTimeAsync(1);
            // clearing all mocks before checking what happens when calling: `onRTCSessionMemberUpdate`
            (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" }),
            );

@@ -534,7 +520,7 @@ 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);
        });
    });
@@ -546,7 +532,7 @@ describe("MembershipManager", () => {
                { delayedLeaveEventRestartMs: 10_000, delayedLeaveEventDelayMs: 30_000 },
                room,
                client,
-                () => undefined,
+                { id: "", application: "m.call" },
            );
            manager.join([focus], focusActive);
            await jest.advanceTimersByTimeAsync(1);
@@ -554,17 +540,17 @@ 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 });
            }
        });

@@ -577,7 +563,8 @@ describe("MembershipManager", () => {
                { membershipEventExpiryMs: expire, membershipEventExpiryHeadroomMs: headroom },
                room,
                client,
-                () => undefined,
+
+                { id: "", application: "m.call" },
            );
            manager.join([focus], focusActive);
            await waitForMockCall(client.sendStateEvent);
@@ -598,16 +585,17 @@ describe("MembershipManager", () => {
            await testExpires(10_000, 1_000);
        });
    });
+
    describe("status updates", () => {
        it("starts 'Disconnected'", () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            expect(manager.status).toBe(Status.Disconnected);
        });
        it("emits 'Connection' and 'Connected' after join", async () => {
            const handleDelayedEvent = createAsyncHandle<void>(client._unstable_sendDelayedStateEvent);
            const handleStateEvent = createAsyncHandle<void>(client.sendStateEvent);

-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            expect(manager.status).toBe(Status.Disconnected);
            const connectEmit = jest.fn();
            manager.on(MembershipManagerEvent.StatusChanged, connectEmit);
@@ -621,7 +609,7 @@ describe("MembershipManager", () => {
            expect(connectEmit).toHaveBeenCalledWith(Status.Connecting, Status.Connected);
        });
        it("emits 'Disconnecting' and 'Disconnected' after leave", async () => {
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            const connectEmit = jest.fn();
            manager.on(MembershipManagerEvent.StatusChanged, connectEmit);
            manager.join([focus], focusActive);
@@ -637,7 +625,7 @@ describe("MembershipManager", () => {
            it("sends retry if call membership event is still valid at time of retry", async () => {
                const handle = createAsyncHandle(client._unstable_sendDelayedStateEvent);

-                const manager = new MembershipManager({}, room, client, () => undefined);
+                const manager = new MembershipManager({}, room, client, callSession);
                manager.join([focus], focusActive);
                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(1);

@@ -664,7 +652,7 @@ describe("MembershipManager", () => {
                        new Headers({ "Retry-After": "1" }),
                    ),
                );
-                const manager = new MembershipManager({}, room, client, () => undefined);
+                const manager = new MembershipManager({}, room, client, callSession);
                // Should call _unstable_sendDelayedStateEvent but not sendStateEvent because of the
                // RateLimit error.
                manager.join([focus], focusActive);
@@ -684,7 +672,7 @@ describe("MembershipManager", () => {
            it("abandons retry loop if leave() was called before sending state event", async () => {
                const handle = createAsyncHandle(client._unstable_sendDelayedStateEvent);

-                const manager = new MembershipManager({}, room, client, () => undefined);
+                const manager = new MembershipManager({}, room, client, callSession);
                manager.join([focus], focusActive);
                handle.reject?.(
                    new MatrixError(
@@ -710,7 +698,7 @@ 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,
@@ -719,22 +707,22 @@ describe("MembershipManager", () => {
                        new Headers({ "Retry-After": "1" }),
                    ),
                );
-                const manager = new MembershipManager({}, room, client, () => undefined);
+                const manager = new MembershipManager({}, room, client, callSession);
                manager.join([focus], focusActive);

                // 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);
            });
        });
@@ -752,7 +740,7 @@ describe("MembershipManager", () => {
                    new Headers({ "Retry-After": "2" }),
                ),
            );
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive, delayEventSendError);

            for (let i = 0; i < 10; i++) {
@@ -763,7 +751,7 @@ 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,
@@ -772,7 +760,7 @@ describe("MembershipManager", () => {
                    new Headers({ "Retry-After": "1" }),
                ),
            );
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive, delayEventRestartError);

            for (let i = 0; i < 10; i++) {
@@ -783,7 +771,7 @@ describe("MembershipManager", () => {
        it("falls back to using pure state events when some error occurs while sending delayed events", async () => {
            const unrecoverableError = jest.fn();
            (client._unstable_sendDelayedStateEvent as Mock<any>).mockRejectedValue(new HTTPError("unknown", 601));
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive, unrecoverableError);
            await waitForMockCall(client.sendStateEvent);
            expect(unrecoverableError).not.toHaveBeenCalledWith();
@@ -796,7 +784,7 @@ describe("MembershipManager", () => {
                { networkErrorRetryMs: 1000, maximumNetworkErrorRetryCount: 7 },
                room,
                client,
-                () => undefined,
+                callSession,
            );
            manager.join([focus], focusActive, unrecoverableError);
            for (let retries = 0; retries < 7; retries++) {
@@ -814,7 +802,7 @@ describe("MembershipManager", () => {
            (client._unstable_sendDelayedStateEvent as Mock<any>).mockRejectedValue(
                new UnsupportedDelayedEventsEndpointError("not supported", "sendDelayedStateEvent"),
            );
-            const manager = new MembershipManager({}, room, client, () => undefined);
+            const manager = new MembershipManager({}, room, client, callSession);
            manager.join([focus], focusActive, unrecoverableError);
            await jest.advanceTimersByTimeAsync(1);

@@ -822,13 +810,170 @@ describe("MembershipManager", () => {
            expect(client.sendStateEvent).toHaveBeenCalled();
        });
    });
+    describe("probablyLeft", () => {
+        it("emits probablyLeft when the membership manager could not hear back from the server for the duration of the delayed event", async () => {
+            const manager = new MembershipManager(
+                { delayedLeaveEventDelayMs: 10000 },
+                room,
+                client,
+
+                callSession,
+            );
+            const { promise: stuckPromise, reject: rejectStuckPromise } = Promise.withResolvers<EmptyObject>();
+            const probablyLeftEmit = jest.fn();
+            manager.on(MembershipManagerEvent.ProbablyLeft, probablyLeftEmit);
+            manager.join([focus], focusActive);
+            try {
+                // Let the scheduler run one iteration so that we can send the join state event
+                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_restartScheduledDelayedEvent = jest.fn(() => stuckPromise);
+                expect(client.sendStateEvent).toHaveBeenCalledTimes(1);
+                expect(manager.status).toBe(Status.Connected);
+                expect(probablyLeftEmit).not.toHaveBeenCalledWith(true);
+                // We expect the probablyLeft event to be emitted after the `delayedLeaveEventDelayMs` = 10000.
+                // We also track the calls to updated the delayed event that all will never resolve to simulate the server not responding.
+                // The numbers are a bit arbitrary since we use the local timeout that does not perfectly match the 5s check interval in this test.
+                await jest.advanceTimersByTimeAsync(5000);
+                // No emission after 5s
+                expect(probablyLeftEmit).not.toHaveBeenCalledWith(true);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(1);
+
+                await jest.advanceTimersByTimeAsync(4999);
+                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_restartScheduledDelayedEvent as Mock<any>).mockResolvedValue({});
+
+                // Emit after 10s
+                await jest.advanceTimersByTimeAsync(1);
+                expect(client._unstable_restartScheduledDelayedEvent).toHaveBeenCalledTimes(4);
+                expect(probablyLeftEmit).toHaveBeenCalledWith(true);
+
+                // Mock a sync which does not include our own membership
+                await manager.onRTCSessionMemberUpdate([]);
+                // Wait for the current ongoing delayed event sending to finish
+                await jest.advanceTimersByTimeAsync(1);
+                // We should send a new state event and an associated delayed leave event.
+                expect(client._unstable_sendDelayedStateEvent).toHaveBeenCalledTimes(2);
+                expect(client.sendStateEvent).toHaveBeenCalledTimes(2);
+                // At the same time we expect the probablyLeft event to be emitted with false so we are back operational.
+                expect(probablyLeftEmit).toHaveBeenCalledWith(false);
+            } finally {
+                rejectStuckPromise();
+            }
+        });
+    });
+
+    describe("updateCallIntent()", () => {
+        it("should fail if the user has not joined the call", async () => {
+            const manager = new MembershipManager({}, room, client, callSession);
+            // After joining we want our own focus to be the one we select.
+            try {
+                await manager.updateCallIntent("video");
+                throw Error("Should have thrown");
+            } catch {}
+        });
+
+        it("can adjust the intent", async () => {
+            const manager = new MembershipManager({}, room, client, callSession);
+            manager.join([]);
+            expect(manager.isActivated()).toEqual(true);
+            const membership = mockCallMembership({ ...membershipTemplate, user_id: client.getUserId()! }, room.roomId);
+            await manager.onRTCSessionMemberUpdate([membership]);
+            await manager.updateCallIntent("video");
+            expect(client.sendStateEvent).toHaveBeenCalledTimes(2);
+            const eventContent = (client.sendStateEvent as Mock).mock.calls[0][2] as SessionMembershipData;
+            expect(eventContent["created_ts"]).toEqual(membership.createdTs());
+            expect(eventContent["m.call.intent"]).toEqual("video");
+        });
+
+        it("does nothing if the intent doesn't change", async () => {
+            const manager = new MembershipManager({ callIntent: "video" }, room, client, callSession);
+            manager.join([]);
+            expect(manager.isActivated()).toEqual(true);
+            const membership = mockCallMembership(
+                { ...membershipTemplate, "user_id": client.getUserId()!, "m.call.intent": "video" },
+                room.roomId,
+            );
+            await manager.onRTCSessionMemberUpdate([membership]);
+            await manager.updateCallIntent("video");
+            expect(client.sendStateEvent).toHaveBeenCalledTimes(0);
+        });
+    });
+
+    describe("StickyEventMembershipManager", () => {
+        beforeEach(() => {
+            // Provide a default mock that is like the default "non error" server behaviour.
+            (client._unstable_sendStickyDelayedEvent as Mock<any>).mockResolvedValue({ delay_id: "id" });
+            (client._unstable_sendStickyEvent as Mock<any>).mockResolvedValue(undefined);
+        });
+
+        describe("join()", () => {
+            describe("sends an rtc membership event", () => {
+                it("sends a membership event and schedules delayed leave when joining a call", async () => {
+                    const restartScheduledDelayedEventHandle = createAsyncHandle<void>(
+                        client._unstable_restartScheduledDelayedEvent as Mock,
+                    );
+                    const memberManager = new StickyEventMembershipManager(
+                        undefined,
+                        room,
+                        client,
+                        callSession,
+                        "@alice:example.org:AAAAAAA_m.call",
+                    );
+
+                    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", () => {
    const client = makeMockClient("@alice:example.org", "AAAAAAA");
    const room = makeMockRoom([membershipTemplate]);

-    const membershipManager = new MembershipManager(undefined, room, client, () => undefined, logger);
+    const membershipManager = new MembershipManager(undefined, room, client, callSession);

    const spy = jest.spyOn(console, "error");
    // Double join
@@ -25,9 +25,9 @@ describe("OutdatedKeyFilter Test", () => {
        const olderKey = fakeInboundSessionWithTimestamp(300);
        // Simulate receiving out of order keys

-        expect(filter.isOutdated(aKey.participantId, aKey)).toBe(false);
+        expect(filter.isOutdated(aKey.membership, aKey)).toBe(false);
        // Then we receive the most recent key out of order
-        const isOutdated = filter.isOutdated(aKey.participantId, olderKey);
+        const isOutdated = filter.isOutdated(aKey.membership, olderKey);
        // this key is older and should be ignored even if received after
        expect(isOutdated).toBe(true);
    });
@@ -36,7 +36,7 @@ describe("OutdatedKeyFilter Test", () => {
        return {
            keyIndex: 0,
            creationTS: ts,
-            participantId: "@alice:localhost|ABCDE",
+            membership: { userId: "@alice:localhost", deviceId: "ABDE", memberId: "@alice:localhost:ABCDE" },
            key: new Uint8Array(16),
        };
    }
@@ -22,10 +22,9 @@ 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 { getParticipantId } from "../../../src/matrixrtc/utils.ts";
+import { logger } from "../../../src/logger.ts";
+import { getEncryptionKeyMapKey } from "../../../src/matrixrtc/EncryptionManager.ts";
+import { flushPromises } from "../../test-utils/flushPromises.ts";

 describe("RTCEncryptionManager", () => {
    // The manager being tested
@@ -34,6 +33,7 @@ describe("RTCEncryptionManager", () => {
    let mockTransport: Mocked<ToDeviceKeyTransport>;
    let statistics: Statistics;
    let onEncryptionKeysChanged: jest.Mock;
+    let rtcIdentifierProvider: jest.Mock;

    beforeEach(() => {
        statistics = {
@@ -55,14 +55,18 @@ describe("RTCEncryptionManager", () => {
            off: jest.fn(),
        } as unknown as Mocked<ToDeviceKeyTransport>;

+        rtcIdentifierProvider = jest.fn().mockImplementation((userId: string, deviceId: string, memberId: string) => {
+            return `MOCKSHA<${userId}|${deviceId}|${memberId}>`;
+        });
+
        encryptionManager = new RTCEncryptionManager(
-            "@alice:example.org",
-            "DEVICE01",
+            { userId: "@alice:example.org", deviceId: "DEVICE01", memberId: "@alice:example.org:DEVICE01" },
            getMembershipMock,
            mockTransport,
            statistics,
            onEncryptionKeysChanged,
            logger,
+            rtcIdentifierProvider,
        );
    });

@@ -78,13 +82,15 @@ describe("RTCEncryptionManager", () => {
    });

    describe("Sharing Keys", () => {
-        it("Set up my key asap even if no key distribution is needed", () => {
+        it("Set up my key asap even if no key distribution is needed", async () => {
            getMembershipMock.mockReturnValue([]);

            encryptionManager.join(undefined);
            // After join it is too early, key might be lost as no one is listening yet
            expect(onEncryptionKeysChanged).not.toHaveBeenCalled();
+
            encryptionManager.onMembershipsUpdate();
+            await flushPromises();
            // The key should have been rolled out immediately
            expect(onEncryptionKeysChanged).toHaveBeenCalled();
        });
@@ -92,14 +98,15 @@ describe("RTCEncryptionManager", () => {
        it("Should distribute keys to members on join", async () => {
            jest.useFakeTimers();
            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@carl:example.org", "CARLDEVICE"),
            ];
            getMembershipMock.mockReturnValue(members);

            encryptionManager.join(undefined);
            encryptionManager.onMembershipsUpdate();
+            await jest.runOnlyPendingTimersAsync();

            expect(mockTransport.sendKey).toHaveBeenCalledTimes(1);
            expect(mockTransport.sendKey).toHaveBeenCalledWith(
@@ -114,16 +121,22 @@ describe("RTCEncryptionManager", () => {
            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
                expect.any(Uint8Array<ArrayBufferLike>),
                0,
+                {
+                    deviceId: "DEVICE01",
+                    memberId: "@alice:example.org:DEVICE01",
+                    userId: "@alice:example.org",
+                },
                "@alice:example.org:DEVICE01",
            );
        });

        it("Should re-distribute keys to members whom callMemberhsip ts has changed", async () => {
-            let members = [aCallMembership("@bob:example.org", "BOBDEVICE", 1000)];
+            let members = [aStateBaseMembership("@bob:example.org", "BOBDEVICE", 1000)];
            getMembershipMock.mockReturnValue(members);

            encryptionManager.join(undefined);
            encryptionManager.onMembershipsUpdate();
+            await jest.runOnlyPendingTimersAsync();

            expect(mockTransport.sendKey).toHaveBeenCalledTimes(1);
            expect(mockTransport.sendKey).toHaveBeenCalledWith(
@@ -145,7 +158,7 @@ describe("RTCEncryptionManager", () => {
            mockTransport.sendKey.mockClear();
            onEncryptionKeysChanged.mockClear();

-            members = [aCallMembership("@bob:example.org", "BOBDEVICE", 2000)];
+            members = [aStateBaseMembership("@bob:example.org", "BOBDEVICE", 2000)];
            getMembershipMock.mockReturnValue(members);

            // There are no membership change but the callMembership ts has changed (reset?)
@@ -172,8 +185,8 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -194,7 +207,7 @@ describe("RTCEncryptionManager", () => {
            mockTransport.sendKey.mockClear();

            // Carl joins, within the grace period
-            members.push(aCallMembership("@carl:example.org", "CARLDEVICE"));
+            members.push(aStateBaseMembership("@carl:example.org", "CARLDEVICE"));
            await jest.advanceTimersByTimeAsync(gracePeriod / 2);
            encryptionManager.onMembershipsUpdate();

@@ -222,8 +235,8 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -244,12 +257,12 @@ describe("RTCEncryptionManager", () => {
            await jest.advanceTimersByTimeAsync(5 * 60 * 1000);

            // A new member joins, that should trigger a key rotation.
-            members.push(aCallMembership("@carl:example.org", "CARLDEVICE"));
+            members.push(aStateBaseMembership("@carl:example.org", "CARLDEVICE"));
            encryptionManager.onMembershipsUpdate();
            await jest.advanceTimersByTimeAsync(1);

            // A new member joins, within the grace period, but under the delay period
-            members.push(aCallMembership("@david:example.org", "DAVDEVICE"));
+            members.push(aStateBaseMembership("@david:example.org", "DAVDEVICE"));
            await jest.advanceTimersByTimeAsync((useKeyDelay - gracePeriod) / 2);
            encryptionManager.onMembershipsUpdate();

@@ -274,8 +287,8 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -289,7 +302,7 @@ describe("RTCEncryptionManager", () => {
            mockTransport.sendKey.mockClear();

            await jest.advanceTimersByTimeAsync(gracePeriod + 1000);
-            members.push(aCallMembership("@carl:example.org", "CARLDEVICE"));
+            members.push(aStateBaseMembership("@carl:example.org", "CARLDEVICE"));
            encryptionManager.onMembershipsUpdate();

            expect(mockTransport.sendKey).toHaveBeenCalledWith(
@@ -316,8 +329,8 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -330,11 +343,11 @@ describe("RTCEncryptionManager", () => {
            mockTransport.sendKey.mockClear();

            const newJoiners = [
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
-                aCallMembership("@dave:example.org", "DAVEDEVICE"),
-                aCallMembership("@eve:example.org", "EVEDEVICE"),
-                aCallMembership("@frank:example.org", "FRANKDEVICE"),
-                aCallMembership("@george:example.org", "GEORGEDEVICE"),
+                aStateBaseMembership("@carl:example.org", "CARLDEVICE"),
+                aStateBaseMembership("@dave:example.org", "DAVEDEVICE"),
+                aStateBaseMembership("@eve:example.org", "EVEDEVICE"),
+                aStateBaseMembership("@frank:example.org", "FRANKDEVICE"),
+                aStateBaseMembership("@george:example.org", "GEORGEDEVICE"),
            ];

            for (const newJoiner of newJoiners) {
@@ -366,8 +379,8 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -396,9 +409,9 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@carl:example.org", "CARLDEVICE"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -419,8 +432,8 @@ describe("RTCEncryptionManager", () => {
            onEncryptionKeysChanged.mockClear();

            const updatedMembers = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
            ];
            getMembershipMock.mockReturnValue(updatedMembers);

@@ -443,6 +456,11 @@ describe("RTCEncryptionManager", () => {
            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
                expect.any(Uint8Array<ArrayBufferLike>),
                1,
+                {
+                    userId: "@alice:example.org",
+                    deviceId: "DEVICE01",
+                    memberId: "@alice:example.org:DEVICE01",
+                },
                "@alice:example.org:DEVICE01",
            );

@@ -452,9 +470,9 @@ describe("RTCEncryptionManager", () => {
        it("Should not distribute keys if encryption is disabled", async () => {
            jest.useFakeTimers();
            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+                aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
+                aStateBaseMembership("@carl:example.org", "CARLDEVICE"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -479,8 +497,7 @@ describe("RTCEncryptionManager", () => {
                emit: emitter.emit.bind(emitter),
            } as unknown as Mocked<ToDeviceKeyTransport>;
            encryptionManager = new RTCEncryptionManager(
-                "@alice:example.org",
-                "DEVICE01",
+                { userId: "@alice:example.org", deviceId: "DEVICE01", memberId: "@alice:example.org:DEVICE01" },
                getMembershipMock,
                mockTransport,
                statistics,
@@ -491,7 +508,7 @@ describe("RTCEncryptionManager", () => {
        it("should not accept keys when manageMediaKeys is disabled", async () => {
            jest.useFakeTimers();

-            const members = [aCallMembership("@bob:example.org", "BOBDEVICE")];
+            const members = [aStateBaseMembership("@bob:example.org", "BOBDEVICE")];
            getMembershipMock.mockReturnValue(members);

            encryptionManager.join({ manageMediaKeys: false });
@@ -500,8 +517,7 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@bob:example.org",
-                "BOBDEVICE",
+                { userId: "@bob:example.org", deviceId: "BOBDEVICE", memberId: "@bob:example.org:BOBDEVICE" },
                "AAAAAAAAAAA",
                0 /* KeyId */,
                0 /* Timestamp */,
@@ -515,9 +531,9 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
+                aCallMembership("@bob:example.org", "BOBDEVICE", 1000, "rtcIDBOB1"),
+                aCallMembership("@bob:example.org", "BOBDEVICE2", 1000, "rtcIDBOB2"),
+                aCallMembership("@carl:example.org", "CARLDEVICE", 1000, "rtcIDCARL1"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -527,24 +543,21 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@bob:example.org",
-                "BOBDEVICE",
+                { userId: "@bob:example.org", deviceId: "BOBDEVICE", memberId: "@bob:example.org:BOBDEVICE" },
                "AAAAAAAAAAA",
                0 /* KeyId */,
                0 /* Timestamp */,
            );
            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@bob:example.org",
-                "BOBDEVICE2",
+                { userId: "@bob:example.org", deviceId: "BOBDEVICE2", memberId: "@bob:example.org:BOBDEVICE2" },
                "BBBBBBBBBBB",
                4 /* KeyId */,
                0 /* Timestamp */,
            );
            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@carl:example.org",
-                "CARLDEVICE",
+                { userId: "@carl:example.org", deviceId: "CARLDEVICE", memberId: "@carl:example.org:CARLDEVICE" },
                "CCCCCCCCCC",
                8 /* KeyId */,
                0 /* Timestamp */,
@@ -554,19 +567,34 @@ describe("RTCEncryptionManager", () => {
            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
                decodeBase64("AAAAAAAAAAA"),
                0,
-                "@bob:example.org:BOBDEVICE",
+                {
+                    userId: "@bob:example.org",
+                    deviceId: "BOBDEVICE",
+                    memberId: "@bob:example.org:BOBDEVICE",
+                },
+                "rtcIDBOB1",
            );

            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
                decodeBase64("BBBBBBBBBBB"),
                4,
-                "@bob:example.org:BOBDEVICE2",
+                {
+                    userId: "@bob:example.org",
+                    deviceId: "BOBDEVICE2",
+                    memberId: "@bob:example.org:BOBDEVICE2",
+                },
+                "rtcIDBOB2",
            );

            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
                decodeBase64("CCCCCCCCCC"),
                8,
-                "@carl:example.org:CARLDEVICE",
+                {
+                    userId: "@carl:example.org",
+                    deviceId: "CARLDEVICE",
+                    memberId: "@carl:example.org:CARLDEVICE",
+                },
+                "rtcIDCARL1",
            );

            expect(statistics.counters.roomEventEncryptionKeysReceived).toBe(3);
@@ -575,7 +603,7 @@ describe("RTCEncryptionManager", () => {
        it("Should support quick re-joiner if keys received out of order", async () => {
            jest.useFakeTimers();

-            const members = [aCallMembership("@carl:example.org", "CARLDEVICE")];
+            const members = [aStateBaseMembership("@carol:example.org", "CAROLDEVICE")];
            getMembershipMock.mockReturnValue(members);

            // Let's join
@@ -583,13 +611,13 @@ describe("RTCEncryptionManager", () => {
            await jest.advanceTimersByTimeAsync(10);

            // Simulate Carl leaving then joining back, and key received out of order
+            // XXX This can only happen in legacy because with sticky events the rtcBackendIdentity would be different.
            const initialKey0TimeStamp = 1000;
            const newKey0TimeStamp = 2000;

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@carol:example.org",
-                "CAROLDEVICE",
+                { userId: "@carol:example.org", deviceId: "CAROLDEVICE", memberId: "@carol:example.org:CAROLDEVICE" },
                "BBBBBBBBBBB",
                0 /* KeyId */,
                newKey0TimeStamp,
@@ -599,8 +627,7 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@carol:example.org",
-                "CAROLDEVICE",
+                { userId: "@carol:example.org", deviceId: "CAROLDEVICE", memberId: "@carol:example.org:CAROLDEVICE" },
                "AAAAAAAAAAA",
                0 /* KeyId */,
                initialKey0TimeStamp,
@@ -613,7 +640,12 @@ describe("RTCEncryptionManager", () => {
            expect(onEncryptionKeysChanged).toHaveBeenLastCalledWith(
                decodeBase64("BBBBBBBBBBB"),
                0,
-                "@carol:example.org:CAROLDEVICE",
+                {
+                    userId: "@carol:example.org",
+                    deviceId: "CAROLDEVICE",
+                    memberId: "@carol:example.org:CAROLDEVICE",
+                },
+                "@carol:example.org|CAROLDEVICE",
            );
        });

@@ -621,9 +653,9 @@ describe("RTCEncryptionManager", () => {
            jest.useFakeTimers();

            const members = [
-                aCallMembership("@bob:example.org", "BOBDEVICE"),
-                aCallMembership("@bob:example.org", "BOBDEVICE2"),
-                aCallMembership("@carl:example.org", "CARLDEVICE"),
+                aCallMembership("@bob:example.org", "BOBDEVICE", 1000, "@bob:example.org|BOBDEVICE"),
+                aCallMembership("@bob:example.org", "BOBDEVICE2", 1000, "@bob:example.org|BOBDEVICE2"),
+                aCallMembership("@carl:example.org", "CARLDEVICE", 1000, "@carl:example.org|CARLDEVICE"),
            ];
            getMembershipMock.mockReturnValue(members);

@@ -635,8 +667,7 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@carl:example.org",
-                "CARLDEVICE",
+                { userId: "@carl:example.org", deviceId: "CARLDEVICE", memberId: "@carl:example.org:CARLDEVICE" },
                "BBBBBBBBBBB",
                0 /* KeyId */,
                1000,
@@ -644,8 +675,7 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@carl:example.org",
-                "CARLDEVICE",
+                { userId: "@carl:example.org", deviceId: "CARLDEVICE", memberId: "@carl:example.org:CARLDEVICE" },
                "CCCCCCCCCCC",
                5 /* KeyId */,
                1000,
@@ -653,8 +683,7 @@ describe("RTCEncryptionManager", () => {

            mockTransport.emit(
                KeyTransportEvents.ReceivedKeys,
-                "@bob:example.org",
-                "BOBDEVICE2",
+                { userId: "@bob:example.org", deviceId: "BOBDEVICE2", memberId: "@bob:example.org:BOBDEVICE2" },
                "DDDDDDDDDDD",
                0 /* KeyId */,
                1000,
@@ -663,7 +692,13 @@ describe("RTCEncryptionManager", () => {
            const knownKeys = encryptionManager.getEncryptionKeys();

            // My own key should be there
-            const myRing = knownKeys.get(getParticipantId("@alice:example.org", "DEVICE01"));
+            const myRing = knownKeys.get(
+                getEncryptionKeyMapKey({
+                    userId: "@alice:example.org",
+                    deviceId: "DEVICE01",
+                    memberId: "@alice:example.org:DEVICE01",
+                }),
+            );
            expect(myRing).toBeDefined();
            expect(myRing).toHaveLength(1);
            expect(myRing![0]).toMatchObject(
@@ -673,7 +708,13 @@ describe("RTCEncryptionManager", () => {
                }),
            );

-            const carlRing = knownKeys.get(getParticipantId("@carl:example.org", "CARLDEVICE"));
+            const carlRing = knownKeys.get(
+                getEncryptionKeyMapKey({
+                    userId: "@carl:example.org",
+                    deviceId: "CARLDEVICE",
+                    memberId: "@carl:example.org:CARLDEVICE",
+                }),
+            );
            expect(carlRing).toBeDefined();
            expect(carlRing).toHaveLength(2);
            expect(carlRing![0]).toMatchObject(
@@ -689,7 +730,13 @@ describe("RTCEncryptionManager", () => {
                }),
            );

-            const bobRing = knownKeys.get(getParticipantId("@bob:example.org", "BOBDEVICE2"));
+            const bobRing = knownKeys.get(
+                getEncryptionKeyMapKey({
+                    userId: "@bob:example.org",
+                    deviceId: "BOBDEVICE2",
+                    memberId: "@bob:example.org:BOBDEVICE2",
+                }),
+            );
            expect(bobRing).toBeDefined();
            expect(bobRing).toHaveLength(1);
            expect(bobRing![0]).toMatchObject(
@@ -699,7 +746,13 @@ describe("RTCEncryptionManager", () => {
                }),
            );

-            const bob1Ring = knownKeys.get(getParticipantId("@bob:example.org", "BOBDEVICE"));
+            const bob1Ring = knownKeys.get(
+                getEncryptionKeyMapKey({
+                    userId: "@bob:example.org",
+                    deviceId: "BOBDEVICE",
+                    memberId: "@bob:example.org:BOBDEVICE",
+                }),
+            );
            expect(bob1Ring).not.toBeDefined();
        });
    });
@@ -708,9 +761,9 @@ describe("RTCEncryptionManager", () => {
        jest.useFakeTimers();

        let members = [
-            aCallMembership("@bob:example.org", "BOBDEVICE"),
-            aCallMembership("@bob:example.org", "BOBDEVICE2"),
-            aCallMembership("@carl:example.org", "CARLDEVICE"),
+            aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+            aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
+            aStateBaseMembership("@carl:example.org", "CARLDEVICE"),
        ];
        getMembershipMock.mockReturnValue(members);

@@ -723,12 +776,20 @@ describe("RTCEncryptionManager", () => {
        expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
            expect.any(Uint8Array<ArrayBufferLike>),
            0,
+            {
+                deviceId: "DEVICE01",
+                memberId: "@alice:example.org:DEVICE01",
+                userId: "@alice:example.org",
+            },
            "@alice:example.org:DEVICE01",
        );
        onEncryptionKeysChanged.mockClear();

        // Trigger a key rotation with a leaver
-        members = [aCallMembership("@bob:example.org", "BOBDEVICE"), aCallMembership("@bob:example.org", "BOBDEVICE2")];
+        members = [
+            aStateBaseMembership("@bob:example.org", "BOBDEVICE"),
+            aStateBaseMembership("@bob:example.org", "BOBDEVICE2"),
+        ];
        getMembershipMock.mockReturnValue(members);

        // This should start a new key rollout
@@ -736,7 +797,7 @@ describe("RTCEncryptionManager", () => {
        await jest.advanceTimersByTimeAsync(10);

        // Now simulate a new leaver
-        members = [aCallMembership("@bob:example.org", "BOBDEVICE")];
+        members = [aStateBaseMembership("@bob:example.org", "BOBDEVICE")];
        getMembershipMock.mockReturnValue(members);

        // The key `1` rollout is in progress
@@ -744,7 +805,7 @@ describe("RTCEncryptionManager", () => {
        await jest.advanceTimersByTimeAsync(10);

        // And another one ( plus a joiner)
-        const lastMembership = [aCallMembership("@bob:example.org", "BOBDEVICE3")];
+        const lastMembership = [aStateBaseMembership("@bob:example.org", "BOBDEVICE3")];
        getMembershipMock.mockReturnValue(lastMembership);
        // The key `1` rollout is still in progress
        encryptionManager.onMembershipsUpdate();
@@ -759,11 +820,21 @@ describe("RTCEncryptionManager", () => {
        expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
            expect.any(Uint8Array<ArrayBufferLike>),
            1,
+            {
+                deviceId: "DEVICE01",
+                userId: "@alice:example.org",
+                memberId: "@alice:example.org:DEVICE01",
+            },
            "@alice:example.org:DEVICE01",
        );
        expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
            expect.any(Uint8Array<ArrayBufferLike>),
            2,
+            {
+                deviceId: "DEVICE01",
+                memberId: "@alice:example.org:DEVICE01",
+                userId: "@alice:example.org",
+            },
            "@alice:example.org:DEVICE01",
        );

@@ -782,90 +853,153 @@ 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>;
+    describe("RTC backend pseudonymous id", () => {
+        it("Should use pseudo rtcBackendIdentity if using sticky events", async () => {
+            getMembershipMock.mockReturnValue([]);
+            encryptionManager.join({
+                manageMediaKeys: true,
+                unstableSendStickyEvents: true,
+            });
+            encryptionManager.onMembershipsUpdate();

-        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>;
+            await flushPromises();

-        const mockLogger = {
-            debug: jest.fn(),
-            warn: jest.fn(),
-        } as unknown as Mocked<Logger>;
+            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
+                expect.any(Uint8Array<ArrayBufferLike>),
+                0,
+                {
+                    deviceId: "DEVICE01",
+                    userId: "@alice:example.org",
+                    memberId: "@alice:example.org:DEVICE01",
+                },
+                "MOCKSHA<@alice:example.org|DEVICE01|@alice:example.org:DEVICE01>",
+            );
+        });

-        const transport = new RoomAndToDeviceTransport(mockToDeviceTransport, mockRoomTransport, {
-            getChild: jest.fn().mockReturnValue(mockLogger),
-        } as unknown as Mocked<Logger>);
+        it("Should use legacy participant id if not using sticky event", async () => {
+            getMembershipMock.mockReturnValue([]);
+            encryptionManager.join({
+                manageMediaKeys: true,
+                unstableSendStickyEvents: false,
+            });
+            encryptionManager.onMembershipsUpdate();

-        encryptionManager = new RTCEncryptionManager(
-            "@alice:example.org",
-            "DEVICE01",
-            getMembershipMock,
-            transport,
-            statistics,
-            onEncryptionKeysChanged,
-        );
+            await flushPromises();

-        const members = [
-            aCallMembership("@bob:example.org", "BOBDEVICE"),
-            aCallMembership("@bob:example.org", "BOBDEVICE2"),
-            aCallMembership("@carl:example.org", "CARLDEVICE"),
-        ];
-        getMembershipMock.mockReturnValue(members);
+            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
+                expect.any(Uint8Array<ArrayBufferLike>),
+                0,
+                {
+                    deviceId: "DEVICE01",
+                    userId: "@alice:example.org",
+                    memberId: "@alice:example.org:DEVICE01",
+                },
+                "@alice:example.org:DEVICE01",
+            );
+        });

-        // Let's join
-        encryptionManager.join(undefined);
-        encryptionManager.onMembershipsUpdate();
-        await jest.advanceTimersByTimeAsync(10);
+        it("Should use early keys as soon as the membership is known", async () => {
+            const emitter = new TypedEventEmitter<KeyTransportEvents, KeyTransportEventsHandlerMap>();
+            mockTransport = {
+                start: jest.fn(),
+                stop: jest.fn(),
+                sendKey: jest.fn().mockResolvedValue(undefined),
+                on: emitter.on.bind(emitter),
+                off: emitter.off.bind(emitter),
+                emit: emitter.emit.bind(emitter),
+            } as unknown as Mocked<ToDeviceKeyTransport>;

-        // Should have sent the key to the toDevice transport
-        expect(mockToDeviceTransport.sendKey).toHaveBeenCalledTimes(1);
-        expect(mockRoomTransport.sendKey).not.toHaveBeenCalled();
+            encryptionManager = new RTCEncryptionManager(
+                { userId: "@alice:example.org", deviceId: "DEVICE01", memberId: "@alice:example.org:DEVICE01" },
+                getMembershipMock,
+                mockTransport,
+                statistics,
+                onEncryptionKeysChanged,
+                logger,
+                rtcIdentifierProvider,
+            );

-        // Simulate receiving a key by room transport
-        roomEmitter.emit(
-            KeyTransportEvents.ReceivedKeys,
-            "@bob:example.org",
-            "BOBDEVICE",
-            "AAAAAAAAAAA",
-            0 /* KeyId */,
-            0 /* Timestamp */,
-        );
+            getMembershipMock.mockReturnValue([]);
+            encryptionManager.join({
+                manageMediaKeys: true,
+                unstableSendStickyEvents: true,
+            });
+            encryptionManager.onMembershipsUpdate();
+            await flushPromises();

-        await jest.runOnlyPendingTimersAsync();
+            // In 2.0 mode the participant identity is pseudo hashed and known from
+            // the rtc membership itself. If a key is received before we have processed
+            // the membership, we cannot pass it to the media layer yet because we don't know
+            // the rtcBackendIdentity to use.
+            mockTransport.emit(
+                KeyTransportEvents.ReceivedKeys,
+                { userId: "@bob:example.org", deviceId: "BOBDEVICE", memberId: "@bob:example.org:BOBDEVICE" },
+                "AAAAAAAAAAA",
+                0 /* KeyId */,
+                0 /* Timestamp */,
+            );

-        // 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() })),
-        );
+            await flushPromises();
+
+            // No membership yet, cannot process the key, so should not have called the callback
+            expect(onEncryptionKeysChanged).toHaveBeenCalledTimes(1 /* only own key */);
+            expect(onEncryptionKeysChanged).not.toHaveBeenCalledWith(
+                expect.any(Uint8Array<ArrayBufferLike>),
+                0,
+                {
+                    deviceId: "BOBDEVICE",
+                    userId: "@bob:example.org",
+                    memberId: "@bob:example.org:BOBDEVICE",
+                },
+                expect.any(String),
+            );
+
+            // Now process membership
+            const bobRtcId = "MOCKSHA<@bob:example.org|BOBDEVICE|@bob:example.org:BOBDEVICE>";
+            const members = [aCallMembership("@bob:example.org", "BOBDEVICE", 1000, bobRtcId)];
+            getMembershipMock.mockReturnValue(members);
+            encryptionManager.onMembershipsUpdate();
+            await flushPromises();
+
+            expect(onEncryptionKeysChanged).toHaveBeenCalledTimes(2);
+            expect(onEncryptionKeysChanged).toHaveBeenCalledWith(
+                expect.any(Uint8Array<ArrayBufferLike>),
+                0,
+                {
+                    deviceId: "BOBDEVICE",
+                    userId: "@bob:example.org",
+                    memberId: "@bob:example.org:BOBDEVICE",
+                },
+                bobRtcId,
+            );
+        });
    });

-    function aCallMembership(userId: string, deviceId: string, ts: number = 1000): CallMembership {
+    function aCallMembership(
+        userId: string,
+        deviceId: string,
+        ts: number = 1000,
+        rtcBackendIdentity: string,
+    ): CallMembership {
        return mockCallMembership(
            { ...membershipTemplate, user_id: userId, device_id: deviceId, created_ts: ts },
            "!room:id",
+            rtcBackendIdentity,
+        );
+    }
+
+    /**
+     * Creates a basic state membership event for the given user and device.
+     * The rtcBackendIdentity is derived from userId and deviceId as `${userId}|${deviceId}`
+     * @param userId
+     * @param deviceId
+     * @param ts
+     */
+    function aStateBaseMembership(userId: string, deviceId: string, ts: number = 1000): CallMembership {
+        return mockCallMembership(
+            { ...membershipTemplate, user_id: userId, device_id: deviceId, created_ts: ts },
+            "!room:id",
+            `${userId}|${deviceId}`,
        );
    }
 });
@@ -882,6 +1016,7 @@ function expectKeyAtIndexToHaveBeenSentTo(
        expect.arrayContaining([expect.objectContaining({ userId, deviceId })]),
    );
 }
+
 function expectKeyAtIndexNotToHaveBeenSentTo(
    mockTransport: Mocked<ToDeviceKeyTransport>,
    index: number,
@@ -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);
-    });
-});
@@ -50,9 +50,15 @@ describe("ToDeviceKeyTransport", () => {
            },
        };

-        transport = new ToDeviceKeyTransport("@alice:example.org", "MYDEVICE", roomId, mockClient, statistics, {
-            getChild: jest.fn().mockReturnValue(mockLogger),
-        } as unknown as Mocked<Logger>);
+        transport = new ToDeviceKeyTransport(
+            { userId: "@alice:example.org", deviceId: "MYDEVICE", memberId: "@alice:example.org:MYDEVICE" },
+            roomId,
+            mockClient,
+            statistics,
+            {
+                getChild: jest.fn().mockReturnValue(mockLogger),
+            } as unknown as Mocked<Logger>,
+        );
    });

    it("should send my keys on via to device", async () => {
@@ -81,6 +87,7 @@ describe("ToDeviceKeyTransport", () => {
                },
                member: {
                    claimed_device_id: "MYDEVICE",
+                    id: "@alice:example.org:MYDEVICE",
                },
                room_id: roomId,
                session: {
@@ -102,8 +109,13 @@ describe("ToDeviceKeyTransport", () => {
            keyBase64Encoded: string;
            index: number;
        }>();
-        transport.on(KeyTransportEvents.ReceivedKeys, (userId, deviceId, keyBase64Encoded, index, timestamp) => {
-            receivedKeyResolvers.resolve({ userId, deviceId, keyBase64Encoded, index });
+        transport.on(KeyTransportEvents.ReceivedKeys, (membership, keyBase64Encoded, index, _timestamp) => {
+            receivedKeyResolvers.resolve({
+                userId: membership.userId,
+                deviceId: membership.deviceId,
+                keyBase64Encoded,
+                index,
+            });
        });
        transport.start();

@@ -15,13 +15,22 @@ 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";
+import { CallMembership, type SessionMembershipData } from "../../../src/matrixrtc";
 import { secureRandomString } from "../../../src/randomstring";
+import { type CallMembershipIdentityParts } from "src/matrixrtc/EncryptionManager";
+import { logger } from "../../../src/logger.ts";

 export type MembershipData = (SessionMembershipData | {}) & { user_id: string };

+export const owmMemberIdentity: CallMembershipIdentityParts = {
+    deviceId: "AAAAAAA",
+    memberId: "@alice:example.org:AAAAAAA",
+    userId: "@alice:example.org",
+};
+
 export const membershipTemplate: SessionMembershipData & { user_id: string } = {
    application: "m.call",
    call_id: "",
@@ -51,6 +60,11 @@ export type MockClient = Pick<
    | "sendStateEvent"
    | "_unstable_sendDelayedStateEvent"
    | "_unstable_updateDelayedEvent"
+    | "_unstable_cancelScheduledDelayedEvent"
+    | "_unstable_restartScheduledDelayedEvent"
+    | "_unstable_sendScheduledDelayedEvent"
+    | "_unstable_sendStickyEvent"
+    | "_unstable_sendStickyDelayedEvent"
    | "cancelPendingEvent"
 >;
 /**
@@ -64,16 +78,23 @@ 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 +102,16 @@ 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 +155,7 @@ export function makeMockEvent(
    roomId: string | undefined,
    content: any,
    timestamp?: number,
+    stateKey?: string,
 ): MatrixEvent {
    return {
        getType: jest.fn().mockReturnValue(type),
@@ -137,16 +164,39 @@ 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 {
-    return new CallMembership(mockRTCEvent(membershipData, roomId), membershipData);
+export function mockCallMembership(
+    membershipData: MembershipData,
+    roomId: string,
+    rtcBackendIdentity?: string,
+): CallMembership {
+    const ev = mockRTCEvent(membershipData, roomId);
+    (ev.getContent as jest.Mock).mockReturnValue(membershipData);
+    const data = CallMembership.membershipDataFromMatrixEvent(ev);
+    return new CallMembership(ev, data, rtcBackendIdentity ?? "xx", logger);
 }

 export function makeKey(id: number, key: string): { key: string; index: number } {
@@ -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");
+    });
+});
@@ -16,10 +16,11 @@ limitations under the License.

 import { type MockedObject } from "jest-mock";

-import { MatrixEvent, MatrixEventEvent } from "../../../src/models/event";
+import { type IContent, MatrixEvent, MatrixEventEvent } from "../../../src/models/event";
 import { emitPromise } from "../../test-utils/test-utils";
 import {
    type IAnnotatedPushRule,
+    type IStickyEvent,
    type MatrixClient,
    PushRuleActionName,
    Room,
@@ -335,6 +336,31 @@ describe("MatrixEvent", () => {
        }
    });

+    describe("state key packing", () => {
+        it("should pack the state key during encryption", () => {
+            const ev = createStateEvent("$event1:server", "m.room.topic", "", { topic: "" });
+            expect(ev.getStateKey()).toStrictEqual("");
+            ev.makeEncrypted("m.room.encrypted", { ciphertext: "xyz" }, "", "");
+            expect(ev.getStateKey()).toStrictEqual("");
+            expect(ev.getWireStateKey()).toStrictEqual("m.room.topic:");
+
+            const keyedEv = createStateEvent("$event2:server", "m.beacon_info", "@alice:server", {});
+            expect(keyedEv.getStateKey()).toStrictEqual("@alice:server");
+            keyedEv.makeEncrypted("m.room.encrypted", { ciphertext: "xyz" }, "", "");
+            expect(keyedEv.getStateKey()).toStrictEqual("@alice:server");
+            expect(keyedEv.getWireStateKey()).toStrictEqual("m.beacon_info:@alice:server");
+        });
+
+        function createStateEvent(eventId: string, type: string, stateKey: string, content?: IContent): MatrixEvent {
+            return new MatrixEvent({
+                type,
+                state_key: stateKey,
+                content,
+                event_id: eventId,
+            });
+        }
+    });
+
    describe("applyVisibilityEvent", () => {
        it("should emit VisibilityChange if a change was made", async () => {
            const ev = new MatrixEvent({
@@ -379,7 +405,9 @@ describe("MatrixEvent", () => {
            expect(encryptedEvent.isBeingDecrypted()).toBeFalsy();
            expect(encryptedEvent.isDecryptionFailure()).toBeTruthy();
            expect(encryptedEvent.decryptionFailureReason).toEqual(DecryptionFailureCode.UNKNOWN_ERROR);
-            expect(encryptedEvent.isEncryptedDisabledForUnverifiedDevices).toBeFalsy();
+            expect(encryptedEvent.decryptionFailureReason).not.toBe(
+                DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+            );
            expect(encryptedEvent.getContent()).toEqual({
                msgtype: "m.bad.encrypted",
                body: "** Unable to decrypt: Error: test error **",
@@ -403,7 +431,9 @@ describe("MatrixEvent", () => {
            expect(encryptedEvent.decryptionFailureReason).toEqual(
                DecryptionFailureCode.MEGOLM_UNKNOWN_INBOUND_SESSION_ID,
            );
-            expect(encryptedEvent.isEncryptedDisabledForUnverifiedDevices).toBeFalsy();
+            expect(encryptedEvent.decryptionFailureReason).not.toBe(
+                DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+            );
            expect(encryptedEvent.getContent()).toEqual({
                msgtype: "m.bad.encrypted",
                body: "** Unable to decrypt: DecryptionError: uisi **",
@@ -427,7 +457,9 @@ describe("MatrixEvent", () => {
            expect(encryptedEvent.isEncrypted()).toBeTruthy();
            expect(encryptedEvent.isBeingDecrypted()).toBeFalsy();
            expect(encryptedEvent.isDecryptionFailure()).toBeTruthy();
-            expect(encryptedEvent.isEncryptedDisabledForUnverifiedDevices).toBeTruthy();
+            expect(encryptedEvent.decryptionFailureReason).toBe(
+                DecryptionFailureCode.MEGOLM_KEY_WITHHELD_FOR_UNVERIFIED_DEVICE,
+            );
            expect(encryptedEvent.getContent()).toEqual({
                msgtype: "m.bad.encrypted",
                body: "** Unable to decrypt: DecryptionError: The sender has disabled encrypting to unverified devices. **",
@@ -567,6 +599,39 @@ describe("MatrixEvent", () => {
        expect(stateEvent.isState()).toBeTruthy();
        expect(stateEvent.threadRootId).toBeUndefined();
    });
+
+    it("should calculate sticky duration correctly", async () => {
+        const evData: IStickyEvent = {
+            event_id: "$event_id",
+            type: "some_state_event",
+            content: {},
+            sender: "@alice:example.org",
+            origin_server_ts: 50,
+            msc4354_sticky: {
+                duration_ms: 1000,
+            },
+            unsigned: {
+                msc4354_sticky_duration_ttl_ms: 5000,
+            },
+        };
+        try {
+            jest.useFakeTimers();
+            jest.setSystemTime(50);
+            // Prefer unsigned
+            expect(new MatrixEvent({ ...evData } satisfies IStickyEvent).unstableStickyExpiresAt).toEqual(5050);
+            // Fall back to `duration_ms`
+            expect(
+                new MatrixEvent({ ...evData, unsigned: undefined } satisfies IStickyEvent).unstableStickyExpiresAt,
+            ).toEqual(1050);
+            // Prefer current time if `origin_server_ts` is more recent.
+            expect(
+                new MatrixEvent({ ...evData, unsigned: undefined, origin_server_ts: 5000 } satisfies IStickyEvent)
+                    .unstableStickyExpiresAt,
+            ).toEqual(1050);
+        } finally {
+            jest.useRealTimers();
+        }
+    });
 });

 function mainTimelineLiveEventIds(room: Room): Array<string> {
@@ -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 });
@@ -0,0 +1,422 @@
+import { type IStickyEvent, MatrixEvent } from "../../../src";
+import { RoomStickyEventsStore, RoomStickyEventsEvent } from "../../../src/models/room-sticky-events";
+
+describe("RoomStickyEvents", () => {
+    let stickyEvents: RoomStickyEventsStore;
+    const emitSpy: jest.Mock = jest.fn();
+    const stickyEvent: IStickyEvent = {
+        event_id: "$foo:bar",
+        room_id: "!roomId",
+        type: "org.example.any_type",
+        msc4354_sticky: {
+            duration_ms: 15000,
+        },
+        content: {
+            msc4354_sticky_key: "foobar",
+        },
+        sender: "@alice:example.org",
+        origin_server_ts: Date.now(),
+        unsigned: {},
+    };
+
+    beforeEach(() => {
+        emitSpy.mockReset();
+        stickyEvents = new RoomStickyEventsStore();
+        stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+    });
+
+    afterEach(() => {
+        stickyEvents?.clear();
+    });
+
+    describe("addStickyEvents", () => {
+        it("should allow adding an event without a msc4354_sticky_key", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, content: {} })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(1);
+        });
+        it("should not allow adding an event without a msc4354_sticky property", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, msc4354_sticky: undefined })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({ ...stickyEvent, msc4354_sticky: { duration_ms: undefined } as any }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should not allow adding an event without a sender", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, sender: undefined })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should not allow adding an event with an invalid sender", () => {
+            stickyEvents.addStickyEvents([new MatrixEvent({ ...stickyEvent, sender: "not_a_real_sender" })]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should ignore old events", () => {
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({ ...stickyEvent, origin_server_ts: 0, msc4354_sticky: { duration_ms: 1 } }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should be able to just add an event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should not replace events on ID tie break", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({
+                    ...stickyEvent,
+                    event_id: "$abc:bar",
+                }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should not replace a newer event with an older event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([
+                new MatrixEvent({
+                    ...stickyEvent,
+                    origin_server_ts: 1,
+                }),
+            ]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv]);
+        });
+        it("should replace an older event with a newer event", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent, event_id: "$old" });
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$new",
+                origin_server_ts: Date.now() + 2000,
+            });
+            stickyEvents.addStickyEvents([originalEv]);
+            stickyEvents.addStickyEvents([newerEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([newerEv]);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: newerEv, previous: originalEv }], []);
+        });
+        it("should allow multiple events with the same sticky key for different event types", () => {
+            const originalEv = new MatrixEvent({ ...stickyEvent });
+            const anotherEv = new MatrixEvent({
+                ...stickyEvent,
+                type: "org.example.another_type",
+            });
+            stickyEvents.addStickyEvents([originalEv, anotherEv]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([originalEv, anotherEv]);
+        });
+
+        it("should emit when a new sticky event is added", () => {
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+            expect(emitSpy).toHaveBeenCalledWith([ev], [], []);
+        });
+        it("should emit when a new unkeyed sticky event is added", () => {
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+            expect(emitSpy).toHaveBeenCalledWith([ev], [], []);
+        });
+    });
+
+    describe("getStickyEvents", () => {
+        it("should have zero sticky events", () => {
+            expect([...stickyEvents.getStickyEvents()]).toHaveLength(0);
+        });
+        it("should contain a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev]);
+        });
+        it("should contain two sticky events", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            const ev2 = new MatrixEvent({
+                ...stickyEvent,
+                sender: "@fibble:bobble",
+                content: {
+                    msc4354_sticky_key: "bibble",
+                },
+            });
+            stickyEvents.addStickyEvents([ev, ev2]);
+            expect([...stickyEvents.getStickyEvents()]).toEqual([ev, ev2]);
+        });
+    });
+
+    describe("getKeyedStickyEvent", () => {
+        it("should have zero sticky events", () => {
+            expect(
+                stickyEvents.getKeyedStickyEvent(
+                    stickyEvent.sender,
+                    stickyEvent.type,
+                    stickyEvent.content.msc4354_sticky_key!,
+                ),
+            ).toBeUndefined();
+        });
+        it("should return a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect(
+                stickyEvents.getKeyedStickyEvent(
+                    stickyEvent.sender,
+                    stickyEvent.type,
+                    stickyEvent.content.msc4354_sticky_key!,
+                ),
+            ).toEqual(ev);
+        });
+    });
+
+    describe("getUnkeyedStickyEvent", () => {
+        it("should have zero sticky events", () => {
+            expect(stickyEvents.getUnkeyedStickyEvent(stickyEvent.sender, stickyEvent.type)).toEqual([]);
+        });
+        it("should return a sticky event", () => {
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {
+                    msc4354_sticky_key: undefined,
+                },
+            });
+            stickyEvents.addStickyEvents([ev]);
+            expect(stickyEvents.getUnkeyedStickyEvent(stickyEvent.sender, stickyEvent.type)).toEqual([ev]);
+        });
+    });
+
+    describe("cleanExpiredStickyEvents", () => {
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+
+        it("should emit when a sticky event expires", () => {
+            jest.setSystemTime(1000);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: 0,
+            });
+            const evLater = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$baz:bar",
+                sender: "@bob:example.org",
+                origin_server_ts: 1000,
+            });
+            stickyEvents.addStickyEvents([ev, evLater]);
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.advanceTimersByTime(15000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+            // Then expire the next event
+            jest.advanceTimersByTime(1000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [evLater]);
+        });
+        it("should emit two events when both expire at the same time", () => {
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.setSystemTime(0);
+            const ev1 = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$eventA",
+                origin_server_ts: 0,
+            });
+            const ev2 = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$eventB",
+                content: {
+                    msc4354_sticky_key: "key_2",
+                },
+                origin_server_ts: 0,
+            });
+            stickyEvents.addStickyEvents([ev1, ev2]);
+            expect(emitSpy).toHaveBeenCalledWith([ev1, ev2], [], []);
+            jest.advanceTimersByTime(15000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev1, ev2]);
+        });
+        it("should emit when a unkeyed sticky event expires", () => {
+            const emitSpy = jest.fn();
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            jest.setSystemTime(0);
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            jest.advanceTimersByTime(15000);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+        });
+    });
+
+    describe("handleRedaction", () => {
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+        it("should not emit if the event does not exist in the map", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction("$123456");
+            expect(emitSpy).not.toHaveBeenCalled();
+        });
+        it("should emit a remove when the event exists in the map without a predecessor", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(stickyEvent.event_id);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+        });
+        it("should emit a remove when the event has no sticky key", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                content: {},
+                origin_server_ts: Date.now(),
+            });
+            stickyEvents.addStickyEvents([ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(stickyEvent.event_id);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [ev]);
+        });
+        it("should emit an update when the event exists in the map with a predecessor", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(newerEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newerEv }], []);
+        });
+        it("should emit a remove if the previous event has expired", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Expire the older event.
+            jest.advanceTimersByTime(stickyEvent.msc4354_sticky.duration_ms);
+            // Redact the newer event
+            stickyEvents.handleRedaction(newerEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [], [newerEv]);
+        });
+        it("should recurse the chain of events if the previous event has been redacted", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const middleEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            jest.advanceTimersByTime(1000);
+            const newestEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newest-ev",
+                origin_server_ts: Date.now() + 2000,
+            });
+            stickyEvents.addStickyEvents([ev, middleEv, newestEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Mark the middle event as redacted.
+            middleEv.setUnsigned({
+                redacted_because: {
+                    event_id: "$foo",
+                } as any,
+            });
+            // Redact the newer event
+            stickyEvents.handleRedaction(newestEv.getId()!);
+            // expect immediate transition from newestEv -> ev and skipping middleEv
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newestEv }], []);
+        });
+        it("should revert to the most recent valid event regardless of insertion order", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const middleEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            jest.advanceTimersByTime(1000);
+            const newestEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newest-ev",
+                origin_server_ts: Date.now() + 2000,
+            });
+            // Invert in reverse order, to make sure we retain the older events.
+            stickyEvents.addStickyEvents([newestEv, middleEv, ev]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            // Mark the middle event as redacted.
+            middleEv.setUnsigned({
+                redacted_because: {
+                    event_id: "$foo",
+                } as any,
+            });
+            // Redact the newer event
+            stickyEvents.handleRedaction(newestEv.getId()!);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newestEv }], []);
+        });
+        it("should handle redaction when using `handleRedaction` with a `MatrixEvent` parameter", () => {
+            const emitSpy = jest.fn();
+            const ev = new MatrixEvent({
+                ...stickyEvent,
+                origin_server_ts: Date.now(),
+            });
+            jest.advanceTimersByTime(1000); // Advance time so we can insert a newer event.
+            const newerEv = new MatrixEvent({
+                ...stickyEvent,
+                event_id: "$newer-ev",
+                origin_server_ts: Date.now() + 1000,
+            });
+            stickyEvents.addStickyEvents([ev, newerEv]);
+            stickyEvents.on(RoomStickyEventsEvent.Update, emitSpy);
+            stickyEvents.handleRedaction(newerEv);
+            expect(emitSpy).toHaveBeenCalledWith([], [{ current: ev, previous: newerEv }], []);
+        });
+    });
+});
@@ -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("");
+        });
+    });
 });
@@ -22,7 +22,7 @@ import { FeatureSupport, Thread, THREAD_RELATION_TYPE, ThreadEvent } from "../..
 import { makeThreadEvent, mkThread, populateThread } from "../../test-utils/thread";
 import { TestClient } from "../../TestClient";
 import { emitPromise, mkEdit, mkMessage, mkReaction, mock } from "../../test-utils/test-utils";
-import { Direction, EventStatus, EventType, MatrixEvent } from "../../../src";
+import { Direction, EventStatus, EventType, MatrixEvent, RelationType } from "../../../src";
 import { ReceiptType } from "../../../src/@types/read_receipts";
 import { getMockClientWithEventEmitter, mockClientMethodsUser } from "../../test-utils/client";
 import { ReEmitter } from "../../../src/ReEmitter";
@@ -773,6 +773,215 @@ describe("Thread", () => {
                expect(lastEvent).toBe(message1);
                expect(firstEvent).toBe(message2);
            });
+
+            it("Edit events are properly aggregated in threads with server-side support", async () => {
+                // This test reproduces the race condition bug from https://github.com/element-hq/element-web/issues/30617
+                // The bug occurs when edits arrive while the thread is not initialized,
+                // causing aggregation to fail because the target event isn't in the timeline yet
+
+                // Given a thread exists with server-side support enabled
+                const myUserId = "@alice:example.org";
+                const testClient = new TestClient(myUserId, "DEVICE", "ACCESS_TOKEN", undefined, {
+                    timelineSupport: false,
+                });
+                const client = testClient.client;
+                client.supportsThreads = jest.fn().mockReturnValue(true);
+
+                const room = new Room("!room:z", client, myUserId, {
+                    pendingEventOrdering: PendingEventOrdering.Detached,
+                });
+                jest.spyOn(client, "getRoom").mockReturnValue(room);
+
+                // Create a root event
+                const rootEvent = mkMessage({
+                    room: room.roomId,
+                    user: myUserId,
+                    msg: "Root message",
+                    event: true,
+                });
+
+                // Create thread manually - starts with initialEventsFetched = false
+                const thread = new Thread(rootEvent.getId()!, rootEvent, {
+                    room: room,
+                    client: client,
+                    pendingEventOrdering: PendingEventOrdering.Detached,
+                });
+
+                // The thread is NOT initialized - this is the key to reproducing the bug!
+                expect(thread.initialEventsFetched).toBe(false);
+
+                // Create a message that will be edited
+                const originalMessage = mkMessage({
+                    room: room.roomId,
+                    user: myUserId,
+                    msg: "Original message in thread",
+                    relatesTo: {
+                        "rel_type": THREAD_RELATION_TYPE.name,
+                        "event_id": thread.id,
+                        "m.in_reply_to": {
+                            event_id: thread.id,
+                        },
+                    },
+                    event: true,
+                });
+
+                // Create edit events BEFORE the original message is in the timeline
+                const edit1 = mkEdit(originalMessage, client, myUserId, room.roomId, "Edit 1");
+                const edit2 = mkEdit(originalMessage, client, myUserId, room.roomId, "Edit 2");
+                const edit3 = mkEdit(originalMessage, client, myUserId, room.roomId, "Final edit");
+
+                // CRITICAL: Add edits while thread is NOT initialized
+                // They will be queued in replayEvents and aggregation will be attempted but fail
+                await thread.addEvent(edit1, false);
+
+                // Check the aggregation state after adding first edit
+                // With our fix: edits should NOT be aggregated yet (thread not initialized)
+                // Without fix: edits would be aggregated but fail to link to target
+                const relationsAfterFirstEdit = thread.timelineSet.relations?.getChildEventsForEvent(
+                    originalMessage.getId()!,
+                    RelationType.Replace,
+                    EventType.RoomMessage,
+                );
+
+                // With the fix, no aggregation happens yet (which is correct)
+                // Without the fix, aggregation would happen but fail silently
+                expect(relationsAfterFirstEdit).toBeUndefined();
+
+                // Add remaining edits
+                await thread.addEvent(edit2, false);
+                await thread.addEvent(edit3, false);
+
+                // Check that edits went to replayEvents
+                expect(thread.replayEvents).toHaveLength(3);
+
+                // Now initialize the thread and add the original message
+                thread.initialEventsFetched = true;
+
+                // Clear replayEvents and add the original message
+                const replayEvents = [...(thread.replayEvents || [])];
+                thread.replayEvents = [];
+
+                // Add original message first
+                await thread.addEvent(originalMessage, false);
+
+                // At this point, the original message should NOT have the edits aggregated yet
+                // because they were attempted when the target wasn't in timeline
+                const replacingEventBeforeReplay = originalMessage.replacingEvent();
+                // With the fix, edits should not be aggregated yet (pre-init)
+                expect(replacingEventBeforeReplay).toBeNull();
+
+                // Then replay the edits
+                for (const event of replayEvents) {
+                    await thread.addEvent(event, false);
+                }
+
+                // After replay, check aggregation
+                const replacingEvent = originalMessage.replacingEvent();
+
+                // This should now work because edits were re-aggregated when replayed
+                expect(replacingEvent).toBe(edit3);
+
+                // The content should also be updated
+                expect(originalMessage.getContent().body).toBe("Final edit");
+
+                // Relations for replaces should now exist and include all edits in order
+                const replaceRels = thread.timelineSet.relations!.getChildEventsForEvent(
+                    originalMessage.getId()!,
+                    RelationType.Replace,
+                    EventType.RoomMessage,
+                )!;
+                const replaceIds = replaceRels.getRelations().map((e) => e.getId());
+                expect(replaceIds).toHaveLength(3);
+                expect(replaceIds[0]).toBe(edit1.getId());
+                expect(replaceIds[1]).toBe(edit2.getId());
+                expect(replaceIds[2]).toBe(edit3.getId());
+            });
+
+            it("Reactions aggregate pre-init and remain idempotent on replay", async () => {
+                const myUserId = "@alice:example.org";
+                const testClient = new TestClient(myUserId, "DEVICE", "ACCESS_TOKEN", undefined, {
+                    timelineSupport: false,
+                });
+                const client = testClient.client;
+                client.supportsThreads = jest.fn().mockReturnValue(true);
+
+                // Force server-side support so threads start uninitialised
+                const prevSupport = Thread.hasServerSideSupport;
+                Thread.setServerSideSupport(FeatureSupport.Stable);
+
+                try {
+                    const room = new Room("!room:z", client, myUserId, {
+                        pendingEventOrdering: PendingEventOrdering.Detached,
+                    });
+                    jest.spyOn(client, "getRoom").mockReturnValue(room);
+
+                    // Create a root event and thread
+                    const rootEvent = mkMessage({ room: room.roomId, user: myUserId, msg: "Root", event: true });
+                    const thread = new Thread(rootEvent.getId()!, rootEvent, {
+                        room,
+                        client,
+                        pendingEventOrdering: PendingEventOrdering.Detached,
+                    });
+
+                    expect(thread.initialEventsFetched).toBe(false);
+
+                    // A message inside the thread to react to
+                    const originalMessage = mkMessage({
+                        room: room.roomId,
+                        user: myUserId,
+                        msg: "Thread message",
+                        relatesTo: {
+                            "rel_type": THREAD_RELATION_TYPE.name,
+                            "event_id": thread.id,
+                            "m.in_reply_to": { event_id: thread.id },
+                        },
+                        event: true,
+                    });
+
+                    // Create 2 reactions before the message is in the timeline (pre-init)
+                    const reaction1 = mkReaction(originalMessage, client, myUserId, room.roomId);
+                    const reaction2 = mkReaction(originalMessage, client, myUserId, room.roomId);
+
+                    // Add reactions while thread is NOT initialised
+                    thread.addEvent(reaction1, false);
+                    thread.addEvent(reaction2, false);
+
+                    // Relations should already include the reactions pre-init
+                    const relsBefore = thread.timelineSet.relations!.getChildEventsForEvent(
+                        originalMessage.getId()!,
+                        RelationType.Annotation,
+                        EventType.Reaction,
+                    )!;
+                    expect(relsBefore).toBeTruthy();
+                    const beforeIds = new Set(relsBefore.getRelations().map((e) => e.getId()));
+                    expect(beforeIds.size).toBe(2);
+
+                    // Now initialise and replay
+                    // Ensure reactions are queued for replay as well
+                    expect(thread.replayEvents).toHaveLength(2);
+                    const replay = [...(thread.replayEvents || [])];
+                    thread.replayEvents = [];
+                    thread.initialEventsFetched = true;
+
+                    // Add the original message first so it becomes findable
+                    thread.addEvent(originalMessage, false);
+                    // Replay reactions
+                    for (const ev of replay) thread.addEvent(ev, false);
+
+                    // Ensure no duplicates after replay (idempotent aggregation)
+                    const relsAfter = thread.timelineSet.relations!.getChildEventsForEvent(
+                        originalMessage.getId()!,
+                        RelationType.Annotation,
+                        EventType.Reaction,
+                    )!;
+                    const afterIds = new Set(relsAfter.getRelations().map((e) => e.getId()));
+                    expect(afterIds.size).toBe(2);
+                    expect(afterIds).toEqual(beforeIds);
+                } finally {
+                    // restore
+                    Thread.setServerSideSupport(prevSupport);
+                }
+            });
        });
    });
 });
@@ -164,6 +164,23 @@ describe("oidc authorization", () => {

            expect(authUrl.searchParams.get("prompt")).toEqual("create");
        });
+
+        it("should generate url with login_hint", async () => {
+            const nonce = "abc123";
+
+            const authUrl = new URL(
+                await generateOidcAuthorizationUrl({
+                    metadata: delegatedAuthConfig,
+                    homeserverUrl: baseUrl,
+                    clientId,
+                    redirectUri: baseUrl,
+                    nonce,
+                    loginHint: "login1234",
+                }),
+            );
+
+            expect(authUrl.searchParams.get("login_hint")).toEqual("login1234");
+        });
    });

    describe("completeAuthorizationCodeGrant", () => {
@@ -21,7 +21,6 @@ limitations under the License.
 import fetchMock from "fetch-mock-jest";

 import { OidcTokenRefresher, TokenRefreshLogoutError } from "../../../src";
-import { logger } from "../../../src/logger";
 import { makeDelegatedAuthConfig } from "../../test-utils/oidc";

 describe("OidcTokenRefresher", () => {
@@ -78,51 +77,49 @@ describe("OidcTokenRefresher", () => {
        fetchMock.resetBehavior();
    });

-    it("throws when oidc client cannot be initialised", async () => {
-        jest.spyOn(logger, "error");
-        fetchMock.get(
-            `${config.issuer}.well-known/openid-configuration`,
-            {
-                ok: false,
-                status: 404,
-            },
-            { overwriteRoutes: true },
-        );
-        const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
-        await expect(refresher.oidcClientReady).rejects.toThrow();
-        expect(logger.error).toHaveBeenCalledWith(
-            "Failed to initialise OIDC client.",
-            // error from OidcClient
-            expect.any(Error),
-        );
-    });
-
-    it("initialises oidc client", async () => {
-        const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
-        await refresher.oidcClientReady;
-
-        // @ts-ignore peek at private property to see we initialised the client correctly
-        expect(refresher.oidcClient.settings).toEqual(
-            expect.objectContaining({
-                client_id: clientId,
-                redirect_uri: redirectUri,
-                authority: authConfig.issuer,
-                scope,
-            }),
-        );
-    });
-
    describe("doRefreshAccessToken()", () => {
        it("should throw when oidcClient has not been initialised", async () => {
+            fetchMock.get(
+                `${config.issuer}.well-known/openid-configuration`,
+                {
+                    ok: false,
+                    status: 404,
+                },
+                { overwriteRoutes: true },
+            );
+
            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
-            await expect(refresher.doRefreshAccessToken("token")).rejects.toThrow(
-                "Cannot get new token before OIDC client is initialised.",
+            await expect(refresher.doRefreshAccessToken("token")).rejects.toThrow("Failed to initialise OIDC client.");
+        });
+
+        it("should retry initialisation", async () => {
+            fetchMock.get(
+                `${config.issuer}.well-known/openid-configuration`,
+                {
+                    ok: false,
+                    status: 404,
+                },
+                { overwriteRoutes: true },
+            );
+
+            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
+            await expect(refresher.doRefreshAccessToken("token")).rejects.toThrow("Failed to initialise OIDC client.");
+
+            // put the successful mock back
+            fetchMock.get(`${config.issuer}.well-known/openid-configuration`, config, { overwriteRoutes: true });
+
+            const result = await refresher.doRefreshAccessToken("token");
+
+            expect(result).toEqual(
+                expect.objectContaining({
+                    accessToken: "new-access-token",
+                    refreshToken: "new-refresh-token",
+                }),
            );
        });

        it("should refresh the tokens", async () => {
            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
-            await refresher.oidcClientReady;

            const result = await refresher.doRefreshAccessToken("refresh-token");

@@ -140,13 +137,12 @@ describe("OidcTokenRefresher", () => {

        it("should persist the new tokens", async () => {
            const refresher = new OidcTokenRefresher(authConfig.issuer, clientId, redirectUri, deviceId, idTokenClaims);
-            await refresher.oidcClientReady;
            // spy on our stub
-            jest.spyOn(refresher, "persistTokens");
+            jest.spyOn(refresher as any, "persistTokens");

            await refresher.doRefreshAccessToken("refresh-token");

-            expect(refresher.persistTokens).toHaveBeenCalledWith(
+            expect((refresher as any).persistTokens).toHaveBeenCalledWith(
                expect.objectContaining({
                    accessToken: "new-access-token",
                    refreshToken: "new-refresh-token",
@@ -20,8 +20,8 @@ import * as utils from "../test-utils/test-utils";
 import { RoomMember, RoomMemberEvent } from "../../src/models/room-member";
 import {
    createClient,
-    EventType,
    type MatrixClient,
+    MatrixEvent,
    type RoomState,
    UNSTABLE_MSC2666_MUTUAL_ROOMS,
    UNSTABLE_MSC2666_QUERY_MUTUAL_ROOMS,
@@ -101,158 +101,32 @@ describe("RoomMember", function () {
        });
    });

-    describe("setPowerLevelEvent", function () {
-        it("should set 'powerLevel' and 'powerLevelNorm'.", function () {
-            const event = utils.mkEvent({
-                type: "m.room.power_levels",
-                room: roomId,
-                user: userA,
-                content: {
-                    users_default: 20,
-                    users: {
-                        "@bertha:bar": 200,
-                        "@invalid:user": 10, // shouldn't barf on this.
-                    },
-                },
-                event: true,
-            });
-            member.setPowerLevelEvent(event);
-            expect(member.powerLevel).toEqual(20);
-            expect(member.powerLevelNorm).toEqual(10);
-
-            const memberB = new RoomMember(roomId, userB);
-            memberB.setPowerLevelEvent(event);
-            expect(memberB.powerLevel).toEqual(200);
-            expect(memberB.powerLevelNorm).toEqual(100);
-        });
-
-        it("should emit 'RoomMember.powerLevel' if the power level changes.", function () {
-            const event = utils.mkEvent({
-                type: "m.room.power_levels",
-                room: roomId,
-                user: userA,
-                content: {
-                    users_default: 20,
-                    users: {
-                        "@bertha:bar": 200,
-                        "@invalid:user": 10, // shouldn't barf on this.
-                    },
-                },
-                event: true,
-            });
-            let emitCount = 0;
-
-            member.on(RoomMemberEvent.PowerLevel, function (emitEvent, emitMember) {
-                emitCount += 1;
-                expect(emitMember).toEqual(member);
-                expect(emitEvent).toEqual(event);
-            });
-
-            member.setPowerLevelEvent(event);
-            expect(emitCount).toEqual(1);
-            member.setPowerLevelEvent(event); // no-op
-            expect(emitCount).toEqual(1);
-        });
-
-        it("should honour power levels of zero.", function () {
-            const event = utils.mkEvent({
-                type: "m.room.power_levels",
-                room: roomId,
-                user: userA,
-                content: {
-                    users_default: 20,
-                    users: {
-                        "@alice:bar": 0,
-                    },
-                },
-                event: true,
-            });
-            let emitCount = 0;
-
-            // set the power level to something other than zero or we
-            // won't get an event
-            member.powerLevel = 1;
-            member.on(RoomMemberEvent.PowerLevel, function (emitEvent, emitMember) {
-                emitCount += 1;
-                expect(emitMember.userId).toEqual("@alice:bar");
-                expect(emitMember.powerLevel).toEqual(0);
-                expect(emitEvent).toEqual(event);
-            });
-
-            member.setPowerLevelEvent(event);
+    describe("setPowerLevel", function () {
+        it("should set 'powerLevel'.", function () {
+            member.setPowerLevel(0, new MatrixEvent());
            expect(member.powerLevel).toEqual(0);
-            expect(emitCount).toEqual(1);
+            member.setPowerLevel(200, new MatrixEvent());
+            expect(member.powerLevel).toEqual(200);
        });

-        it("should not honor string power levels.", function () {
-            const event = utils.mkEvent({
-                type: "m.room.power_levels",
-                room: roomId,
-                user: userA,
-                content: {
-                    users_default: 20,
-                    users: {
-                        "@alice:bar": "5",
-                    },
-                },
-                event: true,
-            });
-            let emitCount = 0;
+        it("should emit when power level set", function () {
+            const onEmit = jest.fn();
+            member.on(RoomMemberEvent.PowerLevel, onEmit);

-            member.on(RoomMemberEvent.PowerLevel, function (emitEvent, emitMember) {
-                emitCount += 1;
-                expect(emitMember.userId).toEqual("@alice:bar");
-                expect(emitMember.powerLevel).toEqual(20);
-                expect(emitEvent).toEqual(event);
-            });
+            const aMatrixEvent = new MatrixEvent();
+            member.setPowerLevel(10, aMatrixEvent);

-            member.setPowerLevelEvent(event);
-            expect(member.powerLevel).toEqual(20);
-            expect(emitCount).toEqual(1);
+            expect(onEmit).toHaveBeenCalledWith(aMatrixEvent, member);
        });

-        it("should no-op if given a non-state or unrelated event", () => {
-            const fn = jest.spyOn(member, "emit");
-            expect(fn).not.toHaveBeenCalledWith(RoomMemberEvent.PowerLevel);
-            member.setPowerLevelEvent(
-                utils.mkEvent({
-                    type: EventType.RoomPowerLevels,
-                    room: roomId,
-                    user: userA,
-                    content: {
-                        users_default: 20,
-                        users: {
-                            "@alice:bar": "5",
-                        },
-                    },
-                    skey: "invalid",
-                    event: true,
-                }),
-            );
-            const nonStateEv = utils.mkEvent({
-                type: EventType.RoomPowerLevels,
-                room: roomId,
-                user: userA,
-                content: {
-                    users_default: 20,
-                    users: {
-                        "@alice:bar": "5",
-                    },
-                },
-                event: true,
-            });
-            delete nonStateEv.event.state_key;
-            member.setPowerLevelEvent(nonStateEv);
-            member.setPowerLevelEvent(
-                utils.mkEvent({
-                    type: EventType.Sticker,
-                    room: roomId,
-                    user: userA,
-                    content: {},
-                    event: true,
-                }),
-            );
-            expect(fn).not.toHaveBeenCalledWith(RoomMemberEvent.PowerLevel);
+        it("should not emit if new power level is the same", function () {
+            const onEmit = jest.fn();
+            member.on(RoomMemberEvent.PowerLevel, onEmit);
+
+            const aMatrixEvent = new MatrixEvent();
+            member.setPowerLevel(0, aMatrixEvent);
+
+            expect(onEmit).not.toHaveBeenCalled();
        });
    });

@@ -20,6 +20,7 @@ import * as utils from "../test-utils/test-utils";
 import { makeBeaconEvent, makeBeaconInfoEvent } from "../test-utils/beacon";
 import { filterEmitCallsByEventType } from "../test-utils/emitter";
 import { RoomState, RoomStateEvent } from "../../src/models/room-state";
+import { RoomMemberEvent } from "../../src/models/room-member";
 import { type Beacon, BeaconEvent, getBeaconInfoIdentifier } from "../../src/models/beacon";
 import { EventType, RelationType, UNSTABLE_MSC2716_MARKER } from "../../src/@types/event";
 import { MatrixEvent, MatrixEventEvent } from "../../src/models/event";
@@ -38,10 +39,10 @@ describe("RoomState", function () {
    const userLazy = "@lazy:bar";

    let state = new RoomState(roomId);
+    let statev12 = new RoomState(roomId);

    beforeEach(function () {
-        state = new RoomState(roomId);
-        state.setStateEvents([
+        const commonEvents = [
            utils.mkMembership({
                // userA joined
                event: true,
@@ -66,6 +67,11 @@ describe("RoomState", function () {
                    name: "Room name goes here",
                },
            }),
+        ];
+
+        state = new RoomState(roomId);
+        state.setStateEvents([
+            ...commonEvents,
            utils.mkEvent({
                // Room creation
                type: "m.room.create",
@@ -75,6 +81,19 @@ describe("RoomState", function () {
                content: {},
            }),
        ]);
+
+        statev12 = new RoomState(roomId);
+        statev12.setStateEvents([
+            ...commonEvents,
+            utils.mkEvent({
+                // Room creation (v12 version)
+                type: "m.room.create",
+                user: userA,
+                room: roomId,
+                event: true,
+                content: { room_version: "12" },
+            }),
+        ]);
    });

    describe("getMembers", function () {
@@ -259,7 +278,7 @@ describe("RoomState", function () {
            expect(emitCount).toEqual(2);
        });

-        it("should call setPowerLevelEvent on each RoomMember for m.room.power_levels", function () {
+        it("should call setPowerLevel on each RoomMember for m.room.power_levels", function () {
            const powerLevelEvent = utils.mkEvent({
                type: "m.room.power_levels",
                room: roomId,
@@ -273,12 +292,12 @@ describe("RoomState", function () {
            });

            // spy on the room members
-            jest.spyOn(state.members[userA], "setPowerLevelEvent");
-            jest.spyOn(state.members[userB], "setPowerLevelEvent");
+            jest.spyOn(state.members[userA], "setPowerLevel");
+            jest.spyOn(state.members[userB], "setPowerLevel");
            state.setStateEvents([powerLevelEvent]);

-            expect(state.members[userA].setPowerLevelEvent).toHaveBeenCalledWith(powerLevelEvent);
-            expect(state.members[userB].setPowerLevelEvent).toHaveBeenCalledWith(powerLevelEvent);
+            expect(state.members[userA].setPowerLevel).toHaveBeenCalledWith(10, powerLevelEvent);
+            expect(state.members[userB].setPowerLevel).toHaveBeenCalledWith(10, powerLevelEvent);
        });

        it("should call setPowerLevelEvent on a new RoomMember if power levels exist", function () {
@@ -310,6 +329,156 @@ describe("RoomState", function () {
            expect(state.members[userC].powerLevel).toEqual(10);
        });

+        it("should calculate power level correctly", function () {
+            const powerLevelEvent = utils.mkEvent({
+                type: "m.room.power_levels",
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        [userB]: 200,
+                        "@invalid:user": 10, // shouldn't barf on this.
+                    },
+                },
+                event: true,
+            });
+            state.setStateEvents([powerLevelEvent]);
+
+            expect(state.getMember(userA)?.powerLevel).toEqual(20);
+            expect(state.getMember(userB)?.powerLevel).toEqual(200);
+        });
+
+        it("should set 'powerLevel' with a v12 room.", function () {
+            const createEventV12 = utils.mkEvent({
+                type: "m.room.create",
+                room: roomId,
+                sender: userA,
+                content: { room_version: "12" },
+                event: true,
+            });
+            const powerLevelEvent = utils.mkEvent({
+                type: "m.room.power_levels",
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        [userB]: 200,
+                        "@invalid:user": 10, // shouldn't barf on this.
+                    },
+                },
+                event: true,
+            });
+            state.setStateEvents([createEventV12, powerLevelEvent]);
+            expect(state.getMember(userA)?.powerLevel).toEqual(Infinity);
+        });
+
+        it("should honour power levels of zero.", function () {
+            const powerLevelEvent = utils.mkEvent({
+                type: "m.room.power_levels",
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        "@alice:bar": 0,
+                    },
+                },
+                event: true,
+            });
+            let emitCount = 0;
+
+            const memberA = state.getMember(userA)!;
+            // set the power level to something other than zero or we
+            // won't get an event
+            memberA.powerLevel = 1;
+            memberA.on(RoomMemberEvent.PowerLevel, function (emitEvent, emitMember) {
+                emitCount += 1;
+                expect(emitMember.userId).toEqual("@alice:bar");
+                expect(emitMember.powerLevel).toEqual(0);
+                expect(emitEvent).toEqual(powerLevelEvent);
+            });
+
+            state.setStateEvents([powerLevelEvent]);
+            expect(memberA.powerLevel).toEqual(0);
+            expect(emitCount).toEqual(1);
+        });
+
+        it("should not honor string power levels.", function () {
+            const powerLevelEvent = utils.mkEvent({
+                type: "m.room.power_levels",
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        "@alice:bar": "5",
+                    },
+                },
+                event: true,
+            });
+            let emitCount = 0;
+
+            const memberA = state.getMember(userA)!;
+            memberA.on(RoomMemberEvent.PowerLevel, function (emitEvent, emitMember) {
+                emitCount += 1;
+                expect(emitMember.userId).toEqual("@alice:bar");
+                expect(emitMember.powerLevel).toEqual(20);
+                expect(emitEvent).toEqual(powerLevelEvent);
+            });
+
+            state.setStateEvents([powerLevelEvent]);
+            expect(memberA.powerLevel).toEqual(20);
+            expect(emitCount).toEqual(1);
+        });
+
+        it("should no-op if given a non-state or unrelated event", () => {
+            const memberA = state.getMember(userA)!;
+            const fn = jest.spyOn(memberA, "emit");
+            expect(fn).not.toHaveBeenCalledWith(RoomMemberEvent.PowerLevel);
+
+            const powerLevelEvent = utils.mkEvent({
+                type: EventType.RoomPowerLevels,
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        "@alice:bar": "5",
+                    },
+                },
+                skey: "invalid",
+                event: true,
+            });
+
+            state.setStateEvents([powerLevelEvent]);
+            const nonStateEv = utils.mkEvent({
+                type: EventType.RoomPowerLevels,
+                room: roomId,
+                user: userA,
+                content: {
+                    users_default: 20,
+                    users: {
+                        "@alice:bar": "5",
+                    },
+                },
+                event: true,
+            });
+            delete nonStateEv.event.state_key;
+            state.setStateEvents([nonStateEv]);
+            state.setStateEvents([
+                utils.mkEvent({
+                    type: EventType.Sticker,
+                    room: roomId,
+                    user: userA,
+                    content: {},
+                    event: true,
+                }),
+            ]);
+            expect(fn).not.toHaveBeenCalledWith(RoomMemberEvent.PowerLevel);
+        });
+
        it("should call setMembershipEvent on the right RoomMember", function () {
            const memberEvent = utils.mkMembership({
                user: userB,
@@ -851,6 +1020,24 @@ describe("RoomState", function () {
            expect(state.maySendEvent("m.room.other_thing", userA)).toEqual(true);
            expect(state.maySendEvent("m.room.other_thing", userB)).toEqual(false);
        });
+
+        it("should recognise power level of room creators in v12 rooms", function () {
+            const powerLevelEvent = new MatrixEvent({
+                type: "m.room.power_levels",
+                room_id: roomId,
+                sender: userA,
+                state_key: "",
+                content: {
+                    users_default: 0,
+                    state_default: 100,
+                    events_default: 100,
+                    users: {},
+                },
+            });
+            statev12.setStateEvents([powerLevelEvent]);
+
+            expect(statev12.maySendEvent("m.room.name", userA)).toEqual(true);
+        });
    });

    describe("processBeaconEvents", () => {
@@ -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);
        });

@@ -92,9 +92,11 @@ describe("OutgoingRequestsManager", () => {
            await secondRequest;
            await thirdRequest;

-            // outgoingRequests should be called twice in total, as the second and third requests are
-            // processed in the same loop.
-            expect(olmMachine.outgoingRequests).toHaveBeenCalledTimes(2);
+            // outgoingRequests should be called three times in total:
+            // 1. the first time,
+            // 2. the second and third requests processed in the same loop, and
+            // 3. checking that all requests are finished
+            expect(olmMachine.outgoingRequests).toHaveBeenCalledTimes(3);

            expect(processor.makeOutgoingRequest).toHaveBeenCalledTimes(3);
            expect(processor.makeOutgoingRequest).toHaveBeenCalledWith(request1);
@@ -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");
@@ -72,6 +72,7 @@ describe("RoomEncryptor", () => {
                    body: text,
                    msgtype: "m.text",
                }),
+                isState: () => false,
                makeEncrypted: jest.fn().mockReturnValue(undefined),
            } as unknown as Mocked<MatrixEvent>;
        }
@@ -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`] = `
 {
@@ -830,6 +830,7 @@ describe("RustCrypto", () => {
                TEST_DEVICE_ID,
                secretStorage,
                {} as CryptoCallbacks,
+                false,
            );

            async function createSecretStorageKey() {
@@ -853,9 +854,27 @@ describe("RustCrypto", () => {
        });
    });

+    it("getSecretStorageStatus", async () => {
+        const mockSecretStorage = {
+            getDefaultKeyId: jest.fn().mockResolvedValue("blah"),
+            isStored: jest.fn().mockResolvedValue({ blah: {} }),
+        } as unknown as Mocked<ServerSideSecretStorage>;
+        const rustCrypto = await makeTestRustCrypto(undefined, undefined, undefined, mockSecretStorage);
+        await expect(rustCrypto.getSecretStorageStatus()).resolves.toEqual({
+            defaultKeyId: "blah",
+            ready: true,
+            secretStorageKeyValidityMap: {
+                "m.cross_signing.master": true,
+                "m.cross_signing.self_signing": true,
+                "m.cross_signing.user_signing": true,
+            },
+        });
+    });
+
    it("isSecretStorageReady", async () => {
        const mockSecretStorage = {
            getDefaultKeyId: jest.fn().mockResolvedValue(null),
+            isStored: jest.fn().mockResolvedValue(null),
        } as unknown as Mocked<ServerSideSecretStorage>;
        const rustCrypto = await makeTestRustCrypto(undefined, undefined, undefined, mockSecretStorage);
        await expect(rustCrypto.isSecretStorageReady()).resolves.toBe(false);
@@ -2353,6 +2372,7 @@ describe("RustCrypto", () => {

        beforeEach(async () => {
            mockOlmMachine = {
+                queryKeysForUsers: jest.fn().mockReturnValue({}),
                getReceivedRoomKeyBundleData: jest.fn(),
                receiveRoomKeyBundle: jest.fn(),
            } as unknown as Mocked<OlmMachine>;
@@ -2377,6 +2397,7 @@ describe("RustCrypto", () => {
        it("does nothing if there is no key bundle", async () => {
            mockOlmMachine.getReceivedRoomKeyBundleData.mockResolvedValue(undefined);
            await rustCrypto.maybeAcceptKeyBundle("!room_id", "@bob:example.org");
+            expect(mockOlmMachine.queryKeysForUsers).toHaveBeenCalledTimes(1);
            expect(mockOlmMachine.getReceivedRoomKeyBundleData).toHaveBeenCalledTimes(1);
            expect(mockOlmMachine.getReceivedRoomKeyBundleData.mock.calls[0][0].toString()).toEqual("!room_id");
            expect(mockOlmMachine.getReceivedRoomKeyBundleData.mock.calls[0][1].toString()).toEqual("@bob:example.org");
@@ -2416,6 +2437,135 @@ describe("RustCrypto", () => {
            expect(mockOlmMachine.receiveRoomKeyBundle.mock.calls[0][1]).toEqual(new TextEncoder().encode("asdfghjkl"));
        });
    });
+
+    describe("Verification requests", () => {
+        it("fetches device details before room verification requests", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a room verification request
+            const event = mockedEvent("!r:s.co", "@u:s.co", "m.room.message", "m.key.verification.request");
+            await rustCrypto.onLiveEventFromSync(event);
+
+            // Then we first fetch device details
+            expect(outgoingRequestProcessor.makeOutgoingRequest).toHaveBeenCalled();
+
+            // And we handle the verification event as normal
+            expect(olmMachine.receiveVerificationEvent).toHaveBeenCalled();
+        });
+
+        it("does not fetch device details before other verification events", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive some verification event that is not a room request
+            const event = mockedEvent("!r:s.co", "@u:s.co", "m.key.verification.start");
+            await rustCrypto.onLiveEventFromSync(event);
+
+            // Then we do not fetch device details
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+
+            // And we handle the verification event as normal
+            expect(olmMachine.receiveVerificationEvent).toHaveBeenCalled();
+        });
+
+        it("throws an error if sender is missing", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a verification event without a sender
+            // Then we throw
+            const event = mockedEvent("!r:s.co", null, "m.key.verification.start");
+
+            await expect(async () => await rustCrypto.onLiveEventFromSync(event)).rejects.toThrow(
+                "missing sender in the event",
+            );
+
+            // And we do not fetch device details or handle the event
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+            expect(olmMachine.receiveVerificationEvent).not.toHaveBeenCalled();
+        });
+
+        it("throws an error if room is missing", async () => {
+            // Given a RustCrypto
+            const olmMachine = mockedOlmMachine();
+            const outgoingRequestProcessor = mockedOutgoingRequestProcessor();
+            const rustCrypto = makeRustCrypto(olmMachine, outgoingRequestProcessor);
+
+            // When we receive a verification event without a sender
+            // Then we throw
+            const event = mockedEvent(null, "@u:s.co", "m.key.verification.start");
+
+            await expect(async () => await rustCrypto.onLiveEventFromSync(event)).rejects.toThrow(
+                "missing roomId in the event",
+            );
+
+            // And we do not fetch device details or handle the event
+            expect(outgoingRequestProcessor.makeOutgoingRequest).not.toHaveBeenCalled();
+            expect(olmMachine.receiveVerificationEvent).not.toHaveBeenCalled();
+        });
+
+        function mockedOlmMachine(): Mocked<OlmMachine> {
+            return {
+                queryKeysForUsers: jest.fn(),
+                getVerificationRequest: jest.fn(),
+                receiveVerificationEvent: jest.fn(),
+            } as unknown as Mocked<OlmMachine>;
+        }
+
+        function makeRustCrypto(
+            olmMachine: OlmMachine,
+            outgoingRequestProcessor: OutgoingRequestProcessor,
+        ): RustCrypto {
+            const rustCrypto = new RustCrypto(
+                new DebugLogger(debug("test Verification requests")),
+                olmMachine,
+                {} as unknown as MatrixHttpApi<IHttpOpts & { onlyData: true }>,
+                TEST_USER,
+                TEST_DEVICE_ID,
+                {} as ServerSideSecretStorage,
+                {} as CryptoCallbacks,
+            );
+
+            // @ts-ignore mocking outgoingRequestProcessor
+            rustCrypto.outgoingRequestProcessor = outgoingRequestProcessor;
+
+            return rustCrypto;
+        }
+
+        function mockedOutgoingRequestProcessor(): OutgoingRequestProcessor {
+            return {
+                makeOutgoingRequest: jest.fn(),
+            } as unknown as Mocked<OutgoingRequestProcessor>;
+        }
+
+        function mockedEvent(
+            roomId: string | null,
+            senderId: string | null,
+            eventType: string,
+            msgtype?: string | undefined,
+        ): MatrixEvent {
+            return {
+                isState: jest.fn().mockReturnValue(false),
+                getUnsigned: jest.fn().mockReturnValue({}),
+                isDecryptionFailure: jest.fn(),
+                isEncrypted: jest.fn(),
+                getType: jest.fn().mockReturnValue(eventType),
+                getRoomId: jest.fn().mockReturnValue(roomId),
+                getSender: jest.fn().mockReturnValue(senderId),
+                getId: jest.fn(),
+                getStateKey: jest.fn(),
+                getContent: jest.fn().mockReturnValue({ msgtype: msgtype }),
+                getTs: jest.fn(),
+            } as unknown as MatrixEvent;
+        }
+    });
 });

 /** Build a MatrixHttpApi instance */
@@ -156,6 +156,8 @@ describe("VerificationRequest", () => {
            );

            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            todoFixupVerificationRequestContent(verificationRequestContent);
+
            await bobOlmMachine.receiveVerificationEvent(
                JSON.stringify({
                    type: "m.room.message",
@@ -289,6 +291,8 @@ describe("VerificationRequest", () => {
            );

            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            todoFixupVerificationRequestContent(verificationRequestContent);
+
            await bobOlmMachine.receiveVerificationEvent(
                JSON.stringify({
                    type: "m.room.message",
@@ -405,6 +409,8 @@ describe("VerificationRequest", () => {
            );

            const verificationRequestContent = JSON.parse(await bobUserIdentity.verificationRequestContent(methods));
+            todoFixupVerificationRequestContent(verificationRequestContent);
+
            await bobOlmMachine.receiveVerificationEvent(
                JSON.stringify({
                    type: "m.room.message",
@@ -460,6 +466,15 @@ describe("VerificationRequest", () => {
    });
 });

+/**
+ * Needed until https://github.com/matrix-org/matrix-rust-sdk/issues/5643 is fixed.
+ *
+ * Modify the content of the supplied content to include `msgtype: m.key.verification.request`.
+ */
+function todoFixupVerificationRequestContent(content: any) {
+    content.msgtype = "m.key.verification.request";
+}
+
 describe("isVerificationEvent", () => {
    it.each([
        [EventType.KeyVerificationCancel],
@@ -26,6 +26,7 @@ import {
    type ILeftRoom,
    type IRoomEvent,
    type IStateEvent,
+    type IStickyEvent,
    type IStrippedState,
    type ISyncResponse,
    SyncAccumulator,
@@ -571,6 +572,49 @@ describe("SyncAccumulator", function () {
        expect(sa.getJSON().roomsData.knock["!knock:bar"]).toBeUndefined();
    });

+    it("should delete knock state when room transitions from knock to join", () => {
+        const initKnockState = makeKnockState();
+        sa.accumulate(
+            syncSkeleton(
+                {},
+                {},
+                {},
+                {
+                    knock_state: initKnockState,
+                },
+            ),
+        );
+        expect(sa.getJSON().roomsData.knock["!knock:bar"].knock_state).toBe(initKnockState);
+
+        // Room transitions from knock to join (e.g., after approval and joining)
+        const joinState = {
+            account_data: { events: [] },
+            ephemeral: { events: [] },
+            unread_notifications: {},
+            state: {
+                events: [member("bob", KnownMembership.Join)],
+            },
+        };
+
+        const syncResponse = {
+            next_batch: "abc",
+            rooms: {
+                join: {
+                    "!knock:bar": joinState,
+                },
+                invite: {},
+                leave: {},
+            },
+        } as unknown as ISyncResponse;
+
+        sa.accumulate(syncResponse);
+
+        expect(sa.getJSON().roomsData.knock["!knock:bar"]).toBeUndefined();
+        expect(sa.getJSON().roomsData.join["!knock:bar"].state?.events[0]?.content.membership).toEqual(
+            KnownMembership.Join,
+        );
+    });
+
    it("should accumulate read receipts", () => {
        const receipt1 = {
            type: "m.receipt",
@@ -1024,6 +1068,67 @@ describe("SyncAccumulator", function () {
            );
        });
    });
+
+    describe("MSC4354 sticky events", () => {
+        function stickyEvent(ts = 0): IStickyEvent {
+            const msgData = msg("test", "test text");
+            return {
+                ...msgData,
+                msc4354_sticky: {
+                    duration_ms: 1000,
+                },
+                origin_server_ts: ts,
+            };
+        }
+
+        beforeAll(() => {
+            jest.useFakeTimers();
+        });
+
+        afterAll(() => {
+            jest.useRealTimers();
+        });
+
+        it("should accumulate sticky events", () => {
+            jest.setSystemTime(0);
+            const ev = stickyEvent();
+            sa.accumulate(
+                syncSkeleton({
+                    msc4354_sticky: {
+                        events: [ev],
+                    },
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([ev]);
+        });
+        it("should clear stale sticky events", () => {
+            jest.setSystemTime(1000);
+            const ev = stickyEvent(1000);
+            sa.accumulate(
+                syncSkeleton({
+                    msc4354_sticky: {
+                        events: [ev],
+                    },
+                }),
+            );
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([ev]);
+            jest.setSystemTime(2000); // Expire the event
+            sa.accumulate(syncSkeleton({}));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toBeUndefined();
+        });
+
+        it("clears stale sticky events that pretend to be from the distant future", () => {
+            jest.setSystemTime(0);
+            const eventFarInTheFuture = stickyEvent(999999999999);
+            sa.accumulate(syncSkeleton({ msc4354_sticky: { events: [eventFarInTheFuture] } }));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toEqual([
+                eventFarInTheFuture,
+            ]);
+            jest.setSystemTime(1000); // Expire the event
+            sa.accumulate(syncSkeleton({}));
+            expect(sa.getJSON().roomsData[Category.Join]["!foo:bar"].msc4354_sticky?.events).toBeUndefined();
+        });
+    });
 });

 function syncSkeleton(
@@ -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);
    });

@@ -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 () => {
@@ -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", () => {
@@ -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`] = `
 {
@@ -102,8 +102,7 @@ export interface IRoomMemberCountCondition extends IPushRuleCondition<ConditionK
    is: AnyMemberCountCondition;
 }

-export interface ISenderNotificationPermissionCondition
-    extends IPushRuleCondition<ConditionKind.SenderNotificationPermission> {
+export interface ISenderNotificationPermissionCondition extends IPushRuleCondition<ConditionKind.SenderNotificationPermission> {
    key: string;
 }

@@ -15,9 +15,12 @@ limitations under the License.
 */

 import type { ISignatures } from "./signed.ts";
+import type { EventDecryptionResult } from "../common-crypto/CryptoBackend.ts";

 // Backwards compatible re-export
-export type { EventDecryptionResult as IEventDecryptionResult } from "../common-crypto/CryptoBackend.ts";
+/** @deprecated This is an internal type and should not be used. */
+type IEventDecryptionResult = EventDecryptionResult;
+export type { IEventDecryptionResult };

 interface Extensible {
    [key: string]: any;
@@ -53,11 +53,12 @@ import {
 } from "../webrtc/callEventTypes.ts";
 import {
    type IRTCNotificationContent,
+    type IRTCDeclineContent,
    type EncryptionKeysEventContent,
    type ICallNotifyContent,
 } from "../matrixrtc/types.ts";
 import { type M_POLL_END, type M_POLL_START, type PollEndEventContent, type PollStartEventContent } from "./polls.ts";
-import { type SessionMembershipData } from "../matrixrtc/CallMembership.ts";
+import { type RtcMembershipData, type SessionMembershipData } from "../matrixrtc/CallMembership.ts";
 import { type LocalNotificationSettings } from "./local_notifications.ts";
 import { type IPushRules } from "./PushRules.ts";
 import { type SecretInfo, type SecretStorageKeyDescription } from "../secret-storage.ts";
@@ -150,8 +151,10 @@ export enum EventType {
    GroupCallMemberPrefix = "org.matrix.msc3401.call.member",

    // MatrixRTC events
+    RTCMembership = "org.matrix.msc4143.rtc.member",
    CallNotify = "org.matrix.msc4075.call.notify",
    RTCNotification = "org.matrix.msc4075.rtc.notification",
+    RTCDecline = "org.matrix.msc4310.rtc.decline",
 }

 export enum RelationType {
@@ -163,7 +166,6 @@ export enum RelationType {
    // moreover, our tests currently use the unstable prefix. Use THREAD_RELATION_TYPE.name.
    // Once we support *only* the stable prefix, THREAD_RELATION_TYPE can die and we can switch to this.
    Thread = "m.thread",
-    unstable_RTCNotificationParent = "org.matrix.msc4075.rtc.notification.parent",
 }

 export enum MsgType {
@@ -332,9 +334,11 @@ export interface TimelineEvents {
    [EventType.CallEncryptionKeysPrefix]: EncryptionKeysEventContent;
    [EventType.CallNotify]: ICallNotifyContent;
    [EventType.RTCNotification]: IRTCNotificationContent;
+    [EventType.RTCDecline]: IRTCDeclineContent;
    [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.
 }

 /**
@@ -367,7 +371,7 @@ export interface StateEvents {
    // MSC3401
    [EventType.GroupCallPrefix]: IGroupCallRoomState;
    [EventType.GroupCallMemberPrefix]: IGroupCallRoomMemberState | SessionMembershipData | EmptyObject;
-
+    [EventType.RTCMembership]: RtcMembershipData | EmptyObject;
    // MSC3089
    [UNSTABLE_MSC3089_BRANCH.name]: MSC3089EventContent;

@@ -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;
@@ -62,6 +62,6 @@ declare global {

    interface Uint8ArrayConstructor {
        // https://tc39.es/proposal-arraybuffer-base64/spec/#sec-uint8array.frombase64
-        fromBase64?(base64: string, options?: Uint8ArrayFromBase64Options): Uint8Array;
+        fromBase64?(base64: string, options?: Uint8ArrayFromBase64Options): Uint8Array<ArrayBuffer>;
    }
 }
@@ -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";

@@ -27,11 +28,6 @@ import { type EventType, type RelationType, type RoomType } from "./event.ts";
 /* eslint-disable camelcase */

 export interface IJoinRoomOpts {
-    /**
-     * @deprecated does nothing
-     */
-    syncRoom?: boolean;
-
    /**
     * If the caller has a keypair 3pid invite, the signing URL is passed in this parameter.
     */
@@ -39,6 +35,7 @@ export interface IJoinRoomOpts {

    /**
     * The server names to try and join through in addition to those that are automatically chosen.
+     * Only the first 3 are actually used in the request, to avoid HTTP 414 Request-URI Too Long responses.
     */
    viaServers?: string[];

@@ -76,6 +73,7 @@ export interface KnockRoomOpts {

    /**
     * The server names to try and knock through in addition to those that are automatically chosen.
+     * Only the first 3 are actually used in the request, to avoid HTTP 414 Request-URI Too Long responses.
     */
    viaServers?: string | string[];
 }
@@ -99,19 +97,20 @@ export interface ISendEventResponse {
    event_id: string;
 }

-export type TimeoutDelay = {
-    delay: number;
-};
-
-export type ParentDelayId = {
-    parent_delay_id: string;
-};
-
-export type SendTimeoutDelayedEventRequestOpts = TimeoutDelay & Partial<ParentDelayId>;
-export type SendActionDelayedEventRequestOpts = ParentDelayId;
-
-export type SendDelayedEventRequestOpts = SendTimeoutDelayedEventRequestOpts | SendActionDelayedEventRequestOpts;
+export type SendDelayedEventRequestOpts = { parent_delay_id: string } | { delay: number; parent_delay_id?: string };

+export function isSendDelayedEventRequestOpts(opts: object): opts is SendDelayedEventRequestOpts {
+    if ("parent_delay_id" in opts && typeof opts.parent_delay_id !== "string") {
+        // Invalid type, reject
+        return false;
+    }
+    if ("delay" in opts && typeof opts.delay !== "number") {
+        // Invalid type, reject.
+        return true;
+    }
+    // At least one of these fields must be specified.
+    return "delay" in opts || "parent_delay_id" in opts;
+}
 export type SendDelayedEventResponse = {
    delay_id: string;
 };
@@ -138,12 +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;
 };

@@ -289,12 +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 {
@@ -105,9 +105,10 @@ export interface RoomPinnedEventsEventContent {
 }

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

 export interface RoomHistoryVisibilityEventContent {
@@ -47,12 +47,19 @@ export const M_TOPIC = new NamespacedValue("m.topic");
 /**
 * The event content for an m.topic event (in content)
 */
-export type MTopicContent = IMessageRendering[];
+export type MTopicContent = { "m.text": IMessageRendering[] };
+
+/**
+ * A previous incorrect form of m.topic used by matrix-js-sdk
+ * TODO remove this after a few releases
+ *      https://github.com/matrix-org/matrix-js-sdk/pull/4984#pullrequestreview-3174251065
+ */
+export type MalformedMTopicEvent = { "m.topic": IMessageRendering[] };

 /**
 * The event definition for an m.topic event (in content)
 */
-export type MTopicEvent = { "m.topic": MTopicContent };
+export type MTopicEvent = { "m.topic": MTopicContent } | MalformedMTopicEvent;

 /**
 * The event content for an m.room.topic event
@@ -22,9 +22,3 @@ import { type AuthDict } from "../interactive-auth.ts";
 export type UIARequest<T> = T & {
    auth?: AuthDict;
 };
-
-/**
- * Helper type to represent HTTP response body for a UIA enabled endpoint
- * @deprecated - a successful response for a UIA enabled endpoint is no different, UIA is signalled via an error
- */
-export type UIAResponse<T> = T;
@@ -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];
@@ -64,7 +64,7 @@ export function encodeUnpaddedBase64Url(uint8Array: Uint8Array): string {
    return toBase64(uint8Array, { alphabet: "base64url", omitPadding: true });
 }

-function fromBase64(base64: string, options: Uint8ArrayFromBase64Options): Uint8Array {
+function fromBase64(base64: string, options: Uint8ArrayFromBase64Options): Uint8Array<ArrayBuffer> {
    if (typeof Uint8Array.fromBase64 === "function") {
        // Currently this is only supported in Firefox,
        // but we match the options in the hope in the future we can rely on it for all environments.
@@ -80,7 +80,7 @@ function fromBase64(base64: string, options: Uint8ArrayFromBase64Options): Uint8
 * @param base64 - The base64 to decode.
 * @returns The decoded data.
 */
-export function decodeBase64(base64: string): Uint8Array {
+export function decodeBase64(base64: string): Uint8Array<ArrayBuffer> {
    // The function requires us to select an alphabet, but we don't know if base64url was used so we convert.
    return fromBase64(base64.replace(/-/g, "+").replace(/_/g, "/"), { alphabet: "base64", lastChunkHandling: "loose" });
 }
@@ -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
@@ -188,8 +200,9 @@ export interface EventDecryptionResult {
     */
    clearEvent: IClearEvent;
    /**
-     * List of curve25519 keys involved in telling us about the senderCurve25519Key and claimedEd25519Key.
+     * No longer used.
     * See {@link MatrixEvent#getForwardingCurve25519KeyChain}.
+     * @deprecated
     */
    forwardingCurve25519KeyChain?: string[];
    /**
@@ -200,11 +213,6 @@ export interface EventDecryptionResult {
     * ed25519 key claimed by the sender of this event. See {@link MatrixEvent#getClaimedEd25519Key}.
     */
    claimedEd25519Key?: string;
-    /**
-     * Whether the keys for this event have been received via an unauthenticated source (eg via key forwards, or
-     * restored from backup)
-     */
-    untrusted?: boolean;
 }

 /**
@@ -197,7 +197,7 @@ export const makeTopicContent: MakeTopicContent = (topic, htmlTopic) => {
    if (isProvided(topic)) {
        renderings.push({ body: topic, mimetype: "text/plain" });
    }
-    return { topic, [M_TOPIC.name]: renderings };
+    return { topic, [M_TOPIC.name]: { "m.text": renderings } };
 };

 export type TopicState = {
@@ -206,7 +206,11 @@ export type TopicState = {
 };

 export const parseTopicContent = (content: MRoomTopicEventContent): TopicState => {
-    const mtopic = M_TOPIC.findIn<MTopicContent>(content);
+    const mtopicParent = M_TOPIC.findIn<MTopicContent>(content);
+    const mtopic = Array.isArray(mtopicParent) ? mtopicParent : mtopicParent?.["m.text"];
+    // TODO remove support for the old malformed m.topic arrays after a few releases (only allow array in m.text)
+    //      https://github.com/matrix-org/matrix-js-sdk/pull/4984#pullrequestreview-3174251065
+    //const mtopic = M_TOPIC.findIn<MTopicContent>(content)?.["m.text"];
    if (!Array.isArray(mtopic)) {
        return { text: content.topic ?? undefined };
    }
@@ -20,7 +20,7 @@ import type { ToDeviceBatch, ToDevicePayload } from "../models/ToDeviceMessage.t
 import { type Room } from "../models/room.ts";
 import { type DeviceMap } from "../models/device.ts";
 import { type UIAuthCallback } from "../interactive-auth.ts";
-import { type PassphraseInfo, type SecretStorageKeyDescription } from "../secret-storage.ts";
+import { type PassphraseInfo, type SecretStorageKey, type SecretStorageKeyDescription } from "../secret-storage.ts";
 import { type VerificationRequest } from "./verification.ts";
 import {
    type BackupTrustInfo,
@@ -118,6 +118,11 @@ export interface CryptoApi {
     */
    isEncryptionEnabledInRoom(roomId: string): Promise<boolean>;

+    /**
+     * Check if we believe the given room supports encrypted state events.
+     */
+    isStateEncryptionEnabledInRoom(roomId: string): Promise<boolean>;
+
    /**
     * Perform any background tasks that can be done before a message is ready to
     * send, in order to speed up sending of the message.
@@ -364,6 +369,11 @@ export interface CryptoApi {
     */
    isSecretStorageReady(): Promise<boolean>;

+    /**
+     * Inspect the status of secret storage, in more detail than {@link isSecretStorageReady}.
+     */
+    getSecretStorageStatus(): Promise<SecretStorageStatus>;
+
    /**
     * Bootstrap [secret storage](https://spec.matrix.org/v1.12/client-server-api/#storage).
     *
@@ -468,16 +478,6 @@ export interface CryptoApi {
     */
    getVerificationRequestsToDeviceInProgress(userId: string): VerificationRequest[];

-    /**
-     * Finds a DM verification request that is already in progress for the given room id
-     *
-     * @param roomId - the room to use for verification
-     *
-     * @returns the VerificationRequest that is in progress, if any
-     * @deprecated prefer `userId` parameter variant.
-     */
-    findVerificationRequestDMInProgress(roomId: string): VerificationRequest | undefined;
-
    /**
     * Finds a DM verification request that is already in progress for the given room and user.
     *
@@ -545,18 +545,6 @@ export interface CryptoApi {
     */
    getSessionBackupPrivateKey(): Promise<Uint8Array | null>;

-    /**
-     * Store the backup decryption key.
-     *
-     * This should be called if the client has received the key from another device via secret sharing (gossiping).
-     * It is the responsability of the caller to check that the decryption key is valid for the current backup version.
-     *
-     * @param key - the backup decryption key
-     *
-     * @deprecated prefer the variant with a `version` parameter.
-     */
-    storeSessionBackupPrivateKey(key: Uint8Array): Promise<void>;
-
    /**
     * Store the backup decryption key.
     *
@@ -801,45 +789,6 @@ export enum DecryptionFailureCode {

    /** Unknown or unclassified error. */
    UNKNOWN_ERROR = "UNKNOWN_ERROR",
-
-    /** @deprecated only used in legacy crypto */
-    MEGOLM_BAD_ROOM = "MEGOLM_BAD_ROOM",
-
-    /** @deprecated only used in legacy crypto */
-    MEGOLM_MISSING_FIELDS = "MEGOLM_MISSING_FIELDS",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_DECRYPT_GROUP_MESSAGE_ERROR = "OLM_DECRYPT_GROUP_MESSAGE_ERROR",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_ENCRYPTED_MESSAGE = "OLM_BAD_ENCRYPTED_MESSAGE",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_RECIPIENT = "OLM_BAD_RECIPIENT",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_RECIPIENT_KEY = "OLM_BAD_RECIPIENT_KEY",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_ROOM = "OLM_BAD_ROOM",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_SENDER_CHECK_FAILED = "OLM_BAD_SENDER_CHECK_FAILED",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_BAD_SENDER = "OLM_BAD_SENDER",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_FORWARDED_MESSAGE = "OLM_FORWARDED_MESSAGE",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_MISSING_CIPHERTEXT = "OLM_MISSING_CIPHERTEXT",
-
-    /** @deprecated only used in legacy crypto */
-    OLM_NOT_INCLUDED_IN_RECIPIENTS = "OLM_NOT_INCLUDED_IN_RECIPIENTS",
-
-    /** @deprecated only used in legacy crypto */
-    UNKNOWN_ENCRYPTION_ALGORITHM = "UNKNOWN_ENCRYPTION_ALGORITHM",
 }

 /** Base {@link DeviceIsolationMode} kind. */
@@ -1104,8 +1053,6 @@ export type ImportRoomKeyProgressData = ImportRoomKeyFetchProgress | ImportRoomK
 export interface ImportRoomKeysOpts {
    /** Reports ongoing progress of the import process. Can be used for feedback. */
    progressCallback?: (stage: ImportRoomKeyProgressData) => void;
-    /** @deprecated the rust SDK will always such imported keys as untrusted */
-    untrusted?: boolean;
    /** @deprecated not useful externally */
    source?: string;
 }
@@ -1193,13 +1140,6 @@ export interface CryptoCallbacks {
        name: string,
    ) => Promise<[string, Uint8Array] | null>;

-    /** @deprecated: unused with the Rust crypto stack. */
-    getCrossSigningKey?: (keyType: string, pubKey: string) => Promise<Uint8Array | null>;
-    /** @deprecated: unused with the Rust crypto stack. */
-    saveCrossSigningKeys?: (keys: Record<string, Uint8Array>) => void;
-    /** @deprecated: unused with the Rust crypto stack. */
-    shouldUpgradeDeviceVerifications?: (users: Record<string, any>) => Promise<string[]>;
-
    /**
     * Called by {@link CryptoApi.bootstrapSecretStorage} when a new default secret storage key is created.
     *
@@ -1211,24 +1151,30 @@ export interface CryptoCallbacks {
     * @param key - private key to store
     */
    cacheSecretStorageKey?: (keyId: string, keyInfo: SecretStorageKeyDescription, key: Uint8Array) => void;
+}

-    /** @deprecated: unused with the Rust crypto stack. */
-    onSecretRequested?: (
-        userId: string,
-        deviceId: string,
-        requestId: string,
-        secretName: string,
-        deviceTrust: DeviceVerificationStatus,
-    ) => Promise<string | undefined>;
+/**
+ * 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;

-    /** @deprecated: unused with the Rust crypto stack. */
-    getDehydrationKey?: (
-        keyInfo: SecretStorageKeyDescription,
-        checkFunc: (key: Uint8Array) => void,
-    ) => Promise<Uint8Array>;
+    /** The ID of the current default secret storage key. */
+    defaultKeyId: string | null;

-    /** @deprecated: unused with the Rust crypto stack. */
-    getBackupKey?: () => Promise<Uint8Array>;
+    /**
+     * 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;
+    };
 }

 /**
@@ -1243,13 +1189,6 @@ export interface CreateSecretStorageOpts {
     */
    createSecretStorageKey?: () => Promise<GeneratedSecretStorageKey>;

-    /**
-     * The current key backup object. If passed,
-     * the passphrase and recovery key from this backup will be used.
-     * @deprecated Not used by the Rust crypto stack.
-     */
-    keyBackupInfo?: KeyBackupInfo;
-
    /**
     * If true, a new key backup version will be
     * created and the private key stored in the new SSSS store. Ignored if keyBackupInfo
@@ -1261,18 +1200,6 @@ export interface CreateSecretStorageOpts {
     * Reset even if keys already exist.
     */
    setupNewSecretStorage?: boolean;
-
-    /**
-     * Function called to get the user's current key backup passphrase.
-     *
-     * Should return a promise that resolves with a Uint8Array
-     * containing the key, or rejects if the key cannot be obtained.
-     *
-     * Only used when the client has existing key backup, but no secret storage.
-     *
-     * @deprecated Not used by the Rust crypto stack.
-     */
-    getKeyBackupPassphrase?: () => Promise<Uint8Array>;
 }

 /** Types of cross-signing key */
@@ -20,8 +20,10 @@ import { type TypedEventEmitter } from "../models/typed-event-emitter.ts";
 /**
 * An incoming, or outgoing, request to verify a user or a device via cross-signing.
 */
-export interface VerificationRequest
-    extends TypedEventEmitter<VerificationRequestEvent, VerificationRequestEventHandlerMap> {
+export interface VerificationRequest extends TypedEventEmitter<
+    VerificationRequestEvent,
+    VerificationRequestEventHandlerMap
+> {
    /**
     * Unique ID for this verification request.
     *
@@ -114,25 +116,6 @@ export interface VerificationRequest
     */
    cancel(params?: { reason?: string; code?: string }): Promise<void>;

-    /**
-     * Create a {@link Verifier} to do this verification via a particular method.
-     *
-     * If a verifier has already been created for this request, returns that verifier.
-     *
-     * This does *not* send the `m.key.verification.start` event - to do so, call {@link Verifier.verify} on the
-     * returned verifier.
-     *
-     * If no previous events have been sent, pass in `targetDevice` to set who to direct this request to.
-     *
-     * @param method - the name of the verification method to use.
-     * @param targetDevice - details of where to send the request to.
-     *
-     * @returns The verifier which will do the actual verification.
-     *
-     * @deprecated Use {@link VerificationRequest#startVerification} instead.
-     */
-    beginKeyVerification(method: string, targetDevice?: { userId?: string; deviceId?: string }): Verifier;
-
    /**
     * Send an `m.key.verification.start` event to start verification via a particular method.
     *
@@ -163,15 +146,6 @@ export interface VerificationRequest
     */
    get verifier(): Verifier | undefined;

-    /**
-     * Get the data for a QR code allowing the other device to verify this one, if it supports it.
-     *
-     * Only set after a .ready if the other party can scan a QR code, otherwise undefined.
-     *
-     * @deprecated Not supported in Rust Crypto. Use {@link VerificationRequest#generateQRCode} instead.
-     */
-    getQRCodeBytes(): Uint8ClampedArray | undefined;
-
    /**
     * Generate the data for a QR code allowing the other device to verify this one, if it supports it.
     *
@@ -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 {};
    }

@@ -54,14 +54,34 @@ export class ClientStoppedError extends Error {
 }

 /**
- * This error is thrown when the Homeserver does not support the delayed events enpdpoints.
+ * This error is thrown when the Homeserver does not support the delayed events endpoints.
 */
 export class UnsupportedDelayedEventsEndpointError extends Error {
    public constructor(
        message: string,
-        public clientEndpoint: "sendDelayedEvent" | "updateDelayedEvent" | "sendDelayedStateEvent" | "getDelayedEvents",
+        public clientEndpoint:
+            | "sendDelayedEvent"
+            | "updateDelayedEvent"
+            | "cancelScheduledDelayedEvent"
+            | "restartScheduledDelayedEvent"
+            | "sendScheduledDelayedEvent"
+            | "sendDelayedStateEvent"
+            | "getDelayedEvents",
    ) {
        super(message);
        this.name = "UnsupportedDelayedEventsEndpointError";
    }
 }
+
+/**
+ * This error is thrown when the Homeserver does not support the sticky events endpoints.
+ */
+export class UnsupportedStickyEventsEndpointError extends Error {
+    public constructor(
+        message: string,
+        public clientEndpoint: "sendStickyEvent" | "sendStickyStateEvent",
+    ) {
+        super(message);
+        this.name = "UnsupportedStickyEventsEndpointError";
+    }
+}
@@ -25,9 +25,6 @@ export interface MapperOpts {
    preventReEmit?: boolean;
    // decrypt event proactively
    decrypt?: boolean;
-
-    /** @deprecated no longer used */
-    toDevice?: boolean;
 }

 export function eventMapperFor(client: MatrixClient, options: MapperOpts): EventMapper {
@@ -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" });
@@ -18,6 +18,7 @@ import { type IMatrixApiError as IWidgetMatrixError } from "matrix-widget-api";

 import { type IUsageLimit } from "../@types/partials.ts";
 import { type MatrixEvent } from "../models/event.ts";
+import { NamespacedValue } from "../NamespacedValue.ts";

 interface IErrorJson extends Partial<IUsageLimit> {
    [key: string]: any; // extensible
@@ -82,6 +83,8 @@ export class HTTPError extends Error {
 export class MatrixError extends HTTPError {
    // The Matrix 'errcode' value, e.g. "M_FORBIDDEN".
    public readonly errcode?: string;
+    // The Matrix 'error' value.
+    public readonly error?: string;
    // The raw Matrix error JSON used to construct this object.
    public data: IErrorJson;

@@ -108,6 +111,7 @@ export class MatrixError extends HTTPError {
        }
        super(`MatrixError: ${message}`, httpStatus, httpHeaders);
        this.errcode = errorJson.errcode;
+        this.error = errorJson.error;
        this.name = errorJson.errcode || "Unknown error code";
        this.data = errorJson;
    }
@@ -226,3 +230,32 @@ export class TokenRefreshLogoutError extends Error {
        return "TokenRefreshLogoutError";
    }
 }
+
+export const MatrixSafetyErrorCode = new NamespacedValue(null, "ORG.MATRIX.MSC4387_SAFETY");
+
+/***
+ * This error is thrown when the homeserver refuses to handle an action due to a
+ * safety concern.
+ * @see https://github.com/matrix-org/matrix-spec-proposals/pull/4387
+ */
+export class MatrixSafetyError extends MatrixError {
+    /**
+     * The kinds of harms detected by the server.
+     * @see https://github.com/matrix-org/matrix-spec-proposals/pull/4387 for a list of spec defined harms.
+     */
+    public readonly harms: Set<string>;
+    /**
+     * The date at which a request can be reattempted.
+     */
+    public readonly expiry?: Date;
+    public constructor(...props: ConstructorParameters<typeof MatrixError>) {
+        super(...props);
+        const body = props[0];
+
+        this.harms = new Set(body && "harms" in body && Array.isArray(body.harms) ? body.harms : []);
+        this.message = `${super.message} (${[...this.harms].join(", ")})`;
+        if (body && "expiry" in body && typeof body.expiry === "number") {
+            this.expiry = new Date(body.expiry);
+        }
+    }
+}
@@ -34,22 +34,6 @@ import { anySignal, parseErrorResponse, timeoutSignal } from "./utils.ts";
 import { type QueryDict } from "../utils.ts";
 import { TokenRefresher, TokenRefreshOutcome } from "./refresh.ts";

-interface TypedResponse<T> extends Response {
-    json(): Promise<T>;
-}
-
-/**
- * The type returned by {@link FetchHttpApi.request}, etc.
- *
- * If {@link IHttpOpts.onlyData} is unset or false, then the request methods return a
- * {@link https://developer.mozilla.org/en-US/docs/Web/API/Response Response} object,
- * which we abstract via `TypedResponse`. Otherwise, we just cast it to `T`.
- *
- * @typeParam T - The type (specified by the application on the request method) that we will cast the response to.
- * @typeParam O - The type of the options object on the {@link FetchHttpApi} instance.
- */
-export type ResponseType<T, O extends IHttpOpts> = O extends { onlyData: true } | undefined ? T : TypedResponse<T>;
-
 export class FetchHttpApi<O extends IHttpOpts> {
    private abortController = new AbortController();
    private readonly tokenRefresher: TokenRefresher;
@@ -59,7 +43,9 @@ export class FetchHttpApi<O extends IHttpOpts> {
        public readonly opts: O,
    ) {
        checkObjectHasKeys(opts, ["baseUrl", "prefix"]);
-        opts.onlyData = !!opts.onlyData;
+        if (!opts.onlyData) {
+            throw new Error("Constructing FetchHttpApi without `onlyData=true` is no longer supported.");
+        }
        opts.useAuthorizationHeader = opts.useAuthorizationHeader ?? true;

        this.tokenRefresher = new TokenRefresher(opts);
@@ -91,7 +77,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
        params: Record<string, string | string[]> | undefined,
        prefix: string,
        accessToken?: string,
-    ): Promise<ResponseType<T, O>> {
+    ): Promise<T> {
        if (!this.opts.idBaseUrl) {
            throw new Error("No identity server base URL set");
        }
@@ -132,17 +118,8 @@ export class FetchHttpApi<O extends IHttpOpts> {
     * When `paramOpts.doNotAttemptTokenRefresh` is true, token refresh will not be attempted
     * when an expired token is encountered. Used to only attempt token refresh once.
     *
-     * @returns Promise which resolves to
-     * ```
-     * {
-     *     data: {Object},
-     *     headers: {Object},
-     *     code: {Number},
-     * }
-     * ```
-     * If `onlyData` is set, this will resolve to the `data` object only.
-     * @returns Rejects with an error if a problem occurred.
-     * This includes network problems and Matrix-specific error JSON.
+     * @returns The parsed response.
+     * @throws Error if a problem occurred. This includes network problems and Matrix-specific error JSON.
     */
    public authedRequest<T>(
        method: Method,
@@ -150,7 +127,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
        queryParams: QueryDict = {},
        body?: Body,
        paramOpts: IRequestOpts = {},
-    ): Promise<ResponseType<T, O>> {
+    ): Promise<T> {
        return this.doAuthedRequest<T>(1, method, path, queryParams, body, paramOpts);
    }

@@ -162,7 +139,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
        queryParams: QueryDict,
        body?: Body,
        paramOpts: IRequestOpts = {},
-    ): Promise<ResponseType<T, O>> {
+    ): Promise<T> {
        // avoid mutating paramOpts so they can be used on retry
        const opts = deepCopy(paramOpts);
        // we have to manually copy the abortSignal over as it is not a plain object
@@ -228,18 +205,8 @@ export class FetchHttpApi<O extends IHttpOpts> {
     *
     * @param opts - additional options
     *
-     * @returns Promise which resolves to
-     * ```
-     * {
-     *  data: {Object},
-     *  headers: {Object},
-     *  code: {Number},
-     * }
-     * ```
-     * If `onlyData</code> is set, this will resolve to the <code>data`
-     * object only.
-     * @returns Rejects with an error if a problem
-     * occurred. This includes network problems and Matrix-specific error JSON.
+     * @returns The parsed response.
+     * @throws Error if a problem occurred. This includes network problems and Matrix-specific error JSON.
     */
    public request<T>(
        method: Method,
@@ -247,7 +214,7 @@ export class FetchHttpApi<O extends IHttpOpts> {
        queryParams?: QueryDict,
        body?: Body,
        opts?: IRequestOpts,
-    ): Promise<ResponseType<T, O>> {
+    ): Promise<T> {
        const fullUri = this.getUrl(path, queryParams, opts?.prefix, opts?.baseUrl);
        return this.requestOtherUrl<T>(method, fullUri, body, opts);
    }
@@ -261,17 +228,15 @@ export class FetchHttpApi<O extends IHttpOpts> {
     *
     * @param opts - additional options
     *
-     * @returns Promise which resolves to data unless `onlyData` is specified as false,
-     * where the resolved value will be a fetch Response object.
-     * @returns Rejects with an error if a problem
-     * occurred. This includes network problems and Matrix-specific error JSON.
+     * @returns The parsed response.
+     * @throws Error if a problem occurred. This includes network problems and Matrix-specific error JSON.
     */
    public async requestOtherUrl<T>(
        method: Method,
        url: URL | string,
        body?: Body,
        opts: BaseRequestOpts = {},
-    ): Promise<ResponseType<T, O>> {
+    ): Promise<T> {
        if (opts.json !== undefined && opts.rawResponseBody !== undefined) {
            throw new Error("Invalid call to `FetchHttpApi` sets both `opts.json` and `opts.rawResponseBody`");
        }
@@ -314,6 +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 {
@@ -326,7 +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,
@@ -349,14 +321,12 @@ export class FetchHttpApi<O extends IHttpOpts> {
            throw parseErrorResponse(res, await res.text());
        }

-        if (!this.opts.onlyData) {
-            return res as ResponseType<T, O>;
-        } else if (opts.rawResponseBody) {
-            return (await res.blob()) as ResponseType<T, O>;
+        if (opts.rawResponseBody) {
+            return (await res.blob()) as T;
        } else if (jsonResponse) {
            return await res.json();
        } else {
-            return (await res.text()) as ResponseType<T, O>;
+            return (await res.text()) as T;
        }
    }

@@ -48,9 +48,9 @@ export class MatrixHttpApi<O extends IHttpOpts> extends FetchHttpApi<O> {
     *
     * @param opts - options object
     *
-     * @returns Promise which resolves to response object, as
-     *    determined by this.opts.onlyData, opts.rawResponse, and
-     *    opts.onlyContentUri.  Rejects with an error (usually a MatrixError).
+     * @returns Promise which resolves to response object, or rejects with an error (usually a MatrixError).
+     * @throws May throw a `MatrixSafetyError` if content is deemed unsafe.
+     * @see MatrixSafetyError
     */
    public uploadContent(file: FileType, opts: UploadOpts = {}): Promise<UploadResponse> {
        const includeFilename = opts.includeFilename ?? true;
@@ -149,11 +149,7 @@ export class MatrixHttpApi<O extends IHttpOpts> extends FetchHttpApi<O> {
                prefix: MediaPrefix.V3,
                headers,
                abortSignal: abortController.signal,
-            })
-                .then((response) => {
-                    return this.opts.onlyData ? <UploadResponse>response : response.json();
-                })
-                .then(uploadResolvers.resolve, uploadResolvers.reject);
+            }).then(uploadResolvers.resolve, uploadResolvers.reject);
        }

        // remove the upload from the list on completion
@@ -69,10 +69,7 @@ export interface IHttpOpts {
    tokenRefreshFunction?: TokenRefreshFunction;
    useAuthorizationHeader?: boolean; // defaults to true

-    /**
-     * Normally, methods in `FetchHttpApi` will return a {@link https://developer.mozilla.org/en-US/docs/Web/API/Response Response} object.
-     * If this is set to `true`, they instead return the response body.
-     */
+    /** For historical reasons, must be set to `true`. Will eventually be removed. */
    onlyData?: boolean;

    localTimeoutMs?: number;
@@ -103,11 +100,10 @@ export interface BaseRequestOpts extends Pick<RequestInit, "priority"> {
     *
     *  * Set `Accept: application/json` in the request headers (again, unless overridden by {@link headers}).
     *
-     *  * If `IHTTPOpts.onlyData` is set to `true` on the `FetchHttpApi` instance, parse the response as
-     *    JSON and return the parsed response.
+     *  * Parse the response as JSON and return the parsed response.
     *
-     * Setting this to `false` inhibits all three behaviors, and (if `IHTTPOpts.onlyData` is set to `true`) the response
-     * is instead parsed as a UTF-8 string. It defaults to `true`, unless {@link rawResponseBody} is set.
+     * Setting this to `false` inhibits all three behaviors, and the response is instead parsed as a UTF-8 string. It
+     * defaults to `true`, unless {@link rawResponseBody} is set.
     *
     * @deprecated Instead of setting this to `false`, set {@link rawResponseBody} to `true`.
     */
@@ -118,9 +114,8 @@ export interface BaseRequestOpts extends Pick<RequestInit, "priority"> {
     *
     *  * Inhibits the automatic addition of `Accept: application/json` in the request headers.
     *
-     *  * Assuming `IHTTPOpts.onlyData` is set to `true` on the `FetchHttpApi` instance, causes the
-     *    raw response to be returned as a {@link https://developer.mozilla.org/en-US/docs/Web/API/Blob|Blob}
-     *    instead of parsing it as `json`.
+     *  * Causes the raw response to be returned as a {@link https://developer.mozilla.org/en-US/docs/Web/API/Blob|Blob}
+     *    instead of parsing it as JSON.
     */
    rawResponseBody?: boolean;
 }
@@ -18,7 +18,14 @@ import { parse as parseContentType, type ParsedMediaType } from "content-type";

 import { logger } from "../logger.ts";
 import { sleep } from "../utils.ts";
-import { ConnectionError, HTTPError, MatrixError, safeGetRetryAfterMs } from "./errors.ts";
+import {
+    ConnectionError,
+    HTTPError,
+    MatrixError,
+    MatrixSafetyError,
+    MatrixSafetyErrorCode,
+    safeGetRetryAfterMs,
+} from "./errors.ts";

 // Ponyfill for https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal/timeout
 export function timeoutSignal(ms: number): AbortSignal {
@@ -92,8 +99,18 @@ export function parseErrorResponse(response: XMLHttpRequest | Response, body?: s
        return <Error>e;
    }
    if (contentType?.type === "application/json" && body) {
+        const errorBody = JSON.parse(body);
+        if (errorBody.errcode && MatrixSafetyErrorCode.matches(errorBody.errcode)) {
+            return new MatrixSafetyError(
+                errorBody,
+                response.status,
+                isXhr(response) ? response.responseURL : response.url,
+                undefined,
+                httpHeaders,
+            );
+        }
        return new MatrixError(
-            JSON.parse(body),
+            errorBody,
            response.status,
            isXhr(response) ? response.responseURL : response.url,
            undefined,
@@ -14,10 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { type MatrixEvent } from "../matrix.ts";
+import { MXID_PATTERN } from "../models/room-member.ts";
 import { deepCompare } from "../utils.ts";
-import { type Focus } from "./focus.ts";
-import { isLivekitFocusActive } from "./LivekitFocus.ts";
+import { type LivekitFocusSelection } from "./LivekitTransport.ts";
+import { slotDescriptionToId, slotIdToDescription, type SlotDescription } from "./MatrixRTCSession.ts";
+import type { RTCCallIntent, Transport } from "./types.ts";
+import { MatrixEvent, type IContent } from "../models/event.ts";
+import { type RelationType } from "../@types/event.ts";
+import { sha256 } from "../digest.ts";
+import { encodeUnpaddedBase64Url } from "../base64.ts";
+import { type Logger } from "../logger.ts";

 /**
 * The default duration in milliseconds that a membership is considered valid for.
@@ -27,16 +33,125 @@ import { isLivekitFocusActive } from "./LivekitFocus.ts";
 export const DEFAULT_EXPIRE_DURATION = 1000 * 60 * 60 * 4;

 type CallScope = "m.room" | "m.user";
+type Member = {
+    user_id: string;
+    device_id: string;
+    /**
+     * The id used on the media backend.
+     * (With livekit this is the participant identity on the LK SFU)
+     * This can be a UUID but right now it is `${this.matrixEventData.sender}:${data.device_id}`.
+     */
+    id: string;
+};
+
+export interface RtcMembershipData {
+    "slot_id": string;
+    "member": Member;
+    "m.relates_to"?: {
+        event_id: string;
+        rel_type: RelationType.Reference;
+    };
+    "application": {
+        type: string;
+        // other application specific keys
+        [key: string]: unknown;
+    };
+    "rtc_transports": Transport[];
+    "versions": string[];
+    "msc4354_sticky_key"?: string;
+    "sticky_key"?: string;
+}
+
+const checkRtcMembershipData = (
+    data: IContent,
+    errors: string[],
+    referenceUserId: string,
+): data is RtcMembershipData => {
+    const prefix = " - ";
+
+    // required fields
+    if (typeof data.slot_id !== "string") {
+        errors.push(prefix + "slot_id must be string");
+    } else {
+        if (data.slot_id.split("#").length !== 2) errors.push(prefix + 'slot_id must include exactly one "#"');
+    }
+    if (typeof data.member !== "object" || data.member === null) {
+        errors.push(prefix + "member must be an object");
+    } else {
+        if (typeof data.member.user_id !== "string") errors.push(prefix + "member.user_id must be string");
+        else if (!MXID_PATTERN.test(data.member.user_id)) errors.push(prefix + "member.user_id must be a valid mxid");
+        // This is not what the spec enforces but there currently are no rules what power levels are required to
+        // send a m.rtc.member event for a other user. So we add this check for simplicity and to avoid possible attacks until there
+        // is a proper definition when this is allowed.
+        else if (data.member.user_id !== referenceUserId) errors.push(prefix + "member.user_id must match the sender");
+        if (typeof data.member.device_id !== "string") errors.push(prefix + "member.device_id must be string");
+        if (typeof data.member.id !== "string") errors.push(prefix + "member.id must be string");
+    }
+    if (typeof data.application !== "object" || data.application === null) {
+        errors.push(prefix + "application must be an object");
+    } else {
+        if (typeof data.application.type !== "string") {
+            errors.push(prefix + "application.type must be a string");
+        } else {
+            if (data.application.type.includes("#")) errors.push(prefix + 'application.type must not include "#"');
+        }
+    }
+    if (data.rtc_transports === undefined || !Array.isArray(data.rtc_transports)) {
+        errors.push(prefix + "rtc_transports must be an array");
+    } else {
+        // validate that each transport has at least a string 'type'
+        for (const t of data.rtc_transports) {
+            if (typeof t !== "object" || t === null || typeof (t as any).type !== "string") {
+                errors.push(prefix + "rtc_transports entries must be objects with a string type");
+                break;
+            }
+        }
+    }
+    if (data.versions === undefined || !Array.isArray(data.versions)) {
+        errors.push(prefix + "versions must be an array");
+    } else if (!data.versions.every((v) => typeof v === "string")) {
+        errors.push(prefix + "versions must be an array of strings");
+    }
+
+    // optional fields
+    if ((data.sticky_key ?? data.msc4354_sticky_key) === undefined) {
+        errors.push(prefix + "sticky_key or msc4354_sticky_key must be a defined");
+    }
+    if (data.sticky_key !== undefined && typeof data.sticky_key !== "string") {
+        errors.push(prefix + "sticky_key must be a string");
+    }
+    if (data.msc4354_sticky_key !== undefined && typeof data.msc4354_sticky_key !== "string") {
+        errors.push(prefix + "msc4354_sticky_key must be a string");
+    }
+    if (
+        data.sticky_key !== undefined &&
+        data.msc4354_sticky_key !== undefined &&
+        data.sticky_key !== data.msc4354_sticky_key
+    ) {
+        errors.push(prefix + "sticky_key and msc4354_sticky_key must be equal if both are defined");
+    }
+    if (data["m.relates_to"] !== undefined) {
+        const rel = data["m.relates_to"] as RtcMembershipData["m.relates_to"];
+        if (typeof rel !== "object" || rel === null) {
+            errors.push(prefix + "m.relates_to must be an object if provided");
+        } else {
+            if (typeof rel.event_id !== "string") errors.push(prefix + "m.relates_to.event_id must be a string");
+            if (rel.rel_type !== "m.reference") errors.push(prefix + "m.relates_to.rel_type must be m.reference");
+        }
+    }
+
+    return errors.length === 0;
+};

 /**
 * MSC4143 (MatrixRTC) session membership data.
- * Represents an entry in the memberships section of an m.call.member event as it is on the wire.
+ * Represents the `session` in the memberships section of an m.call.member event as it is on the wire.
 **/
 export type SessionMembershipData = {
    /**
     * The RTC application defines the type of the RTC session.
     */
-    application: string;
+    "application": string;

    /**
     * The id of this session.
@@ -44,23 +159,23 @@ export type SessionMembershipData = {
     * multiple session in one room. A room wide session that is not associated with a user,
     * and therefore immune to creation race conflicts, uses the `call_id: ""`.
     */
-    call_id: string;
+    "call_id": string;

    /**
     * The Matrix device ID of this session. A single user can have multiple sessions on different devices.
     */
-    device_id: string;
+    "device_id": string;

    /**
     * The focus selection system this user/membership is using.
     */
-    focus_active: Focus;
+    "focus_active": LivekitFocusSelection;

    /**
-     * A list of possible foci this uses knows about. One of them might be used based on the focus_active
+     * A list of possible foci this user knows about. One of them might be used based on the focus_active
     * selection system.
     */
-    foci_preferred: Focus[];
+    "foci_preferred": Transport[];

    /**
     * Optional field that contains the creation of the session. If it is undefined the creation
@@ -69,128 +184,457 @@ export type SessionMembershipData = {
     *  - If it is undefined it can be interpreted as a "Join".
     *  - If it is defined it can be interpreted as an "Update"
     */
-    created_ts?: number;
+    "created_ts"?: number;

    // Application specific data

    /**
     * If the `application` = `"m.call"` this defines if it is a room or user owned call.
-     * There can always be one room scroped call but multiple user owned calls (breakout sessions)
+     * There can always be one room scoped call but multiple user owned calls (breakout sessions)
     */
-    scope?: CallScope;
+    "scope"?: CallScope;

    /**
     * Optionally we allow to define a delta to the `created_ts` that defines when the event is expired/invalid.
     * This should be set to multiple hours. The only reason it exist is to deal with failed delayed events.
     * (for example caused by a homeserver crashes)
     **/
-    expires?: number;
+    "expires"?: number;
+
+    /**
+     * The intent of the call from the perspective of this user. This may be an audio call, video call or
+     * something else.
+     */
+    "m.call.intent"?: RTCCallIntent;
+    /**
+     * The sticky key in case of a sticky event. This string encodes the application + device_id indicating the used slot + device.
+     */
+    "msc4354_sticky_key"?: string;
+
+    /**
+     * The id used on the media backend.
+     * (With livekit this is the participant identity on the LK SFU)
+     * This can be a UUID but right now it is `${this.matrixEventData.sender}:${data.device_id}`.
+     *
+     * It is compleatly valid to not set this field. Other clients will treat `undefined` as `${this.matrixEventData.sender}:${data.device_id}`
+     */
+    "membershipID"?: string;
 };

-const checkSessionsMembershipData = (data: any, errors: string[]): data is SessionMembershipData => {
-    const prefix = "Malformed session membership event: ";
+const checkSessionsMembershipData = (data: IContent, errors: string[]): data is SessionMembershipData => {
+    const prefix = " - ";
    if (typeof data.device_id !== "string") errors.push(prefix + "device_id must be string");
    if (typeof data.call_id !== "string") errors.push(prefix + "call_id must be string");
    if (typeof data.application !== "string") errors.push(prefix + "application must be a string");
    if (typeof data.focus_active?.type !== "string") errors.push(prefix + "focus_active.type must be a string");
-    if (!Array.isArray(data.foci_preferred)) errors.push(prefix + "foci_preferred must be an array");
+    if (data.focus_active === undefined) {
+        errors.push(prefix + "focus_active has an invalid type");
+    }
+    if (
+        data.foci_preferred !== undefined &&
+        !(
+            Array.isArray(data.foci_preferred) &&
+            data.foci_preferred.every(
+                (f: Transport) => typeof f === "object" && f !== null && typeof f.type === "string",
+            )
+        )
+    ) {
+        errors.push(prefix + "foci_preferred must be an array of transport objects");
+    }
    // optional parameters
-    if (data.created_ts && typeof data.created_ts !== "number") errors.push(prefix + "created_ts must be number");
+    if (data.created_ts !== undefined && typeof data.created_ts !== "number") {
+        errors.push(prefix + "created_ts must be number");
+    }

    // application specific data (we first need to check if they exist)
-    if (data.scope && typeof data.scope !== "string") errors.push(prefix + "scope must be string");
+    if (data.scope !== undefined && typeof data.scope !== "string") errors.push(prefix + "scope must be string");
+
+    if (data["m.call.intent"] !== undefined && typeof data["m.call.intent"] !== "string") {
+        errors.push(prefix + "m.call.intent must be a string");
+    }
+
    return errors.length === 0;
 };

+type MembershipData = { kind: "rtc"; data: RtcMembershipData } | { kind: "session"; data: SessionMembershipData };
+// TODO: Rename to RtcMembership once we removed the legacy SessionMembership from this file.
 export class CallMembership {
-    public static equal(a: CallMembership, b: CallMembership): boolean {
-        return deepCompare(a.membershipData, b.membershipData);
+    public static equal(a?: CallMembership, b?: CallMembership): boolean {
+        return deepCompare(a?.membershipData, b?.membershipData);
    }
-    private membershipData: SessionMembershipData;
+
+    private logger?: Logger;
+    /** The parsed data from the Matrix event.
+     * To access checked eventId and sender from the matrixEvent.
+     * Class construction will fail if these values cannot get obtained. */
+    private readonly matrixEventData: { eventId: string; sender: string; ts: number };
+
+    /** Anonymized identity to use with the RTC backend. */
+    public readonly rtcBackendIdentity: string;
+
+    /**
+     * The type checked membership data {data: (content of the matrix event), kind: (type hint)}
+     * @private
+     */
+    private readonly membershipData: MembershipData;

    public constructor(
-        private parentEvent: MatrixEvent,
-        data: any,
+        /** The required parts of the Matrix event that this membership is based on */
+        matrixEvent: Pick<MatrixEvent, "getId" | "getSender" | "getTs">,
+        /**
+         * The type checked membership data {data: (content of the matrix event), kind: (type hint)}
+         * It can be a IContent just for backwards compatibility.
+         * */
+        membershipData: MembershipData | IContent,
+        /**
+         *
+         * Anonymized identity to use with the RTC backend.
+         *
+         * The rtcBackendIdentity is optional only for backwards compatibility. If omitted, the constructor will
+         *  fall back to the legacy `${sender}:${deviceId}` value.
+         * The rtcBackendIdentity is a hashed version of all the identity parts:
+         * `sha256(${this.userId}|${this.deviceId}|${this.memberId})`
+         *
+         * It is used to anonymize the identity of the user in the RTC backend.
+         */
+        rtcBackendIdentity?: string,
+        /**
+         * The constructor will automatically create a properly tagged child logger instance.
+         */
+        logger?: Logger,
    ) {
-        const sessionErrors: string[] = [];
-        if (!checkSessionsMembershipData(data, sessionErrors)) {
-            throw Error(
-                `unknown CallMembership data. Does not match MSC4143 call.member (${sessionErrors.join(" & ")}) events this could be a legacy membership event: (${data})`,
-            );
+        if (membershipData.kind === "rtc" || membershipData.kind === "session") {
+            this.membershipData = membershipData as MembershipData;
+            if (rtcBackendIdentity == undefined) {
+                throw new Error("rtcBackendIdentity must be defined when passing MembershipData");
+            }
+            this.rtcBackendIdentity = rtcBackendIdentity!;
        } else {
-            this.membershipData = data;
+            // Backwards compatibility path for legacy code that passes raw content
+            this.membershipData = CallMembership.membershipDataFromMatrixEvent(
+                new MatrixEvent({
+                    event_id: matrixEvent.getId(),
+                    sender: matrixEvent.getSender(),
+                    content: membershipData,
+                }),
+            );
+            this.rtcBackendIdentity = `${matrixEvent.getSender()}:${this.deviceId}`;
+        }
+        const [eventId, sender, ts] = [matrixEvent.getId(), matrixEvent.getSender(), matrixEvent.getTs()];
+        if (eventId === undefined) throw new Error("parentEvent is missing eventId field");
+        if (sender === undefined) throw new Error("parentEvent is missing sender field");
+
+        this.matrixEventData = { eventId, sender, ts };
+
+        this.logger = logger?.getChild(`[CallMembership ${sender}:${this.deviceId}]`);
+    }
+
+    /**
+     * sha256(`${this.userId}|${this.deviceId}|${this.memberId}`) for sticky events (kind = rtc)
+     * `${this.userId}:${this.deviceId}` for state events (kind = session)
+     */
+    public static async computeRtcBackendIdentity(
+        matrixEvent: Pick<MatrixEvent, "getSender">,
+        membershipData: MembershipData,
+    ): Promise<string> {
+        const { kind, data } = membershipData;
+        switch (kind) {
+            case "rtc": {
+                return CallMembership.computeRtcIdentityRaw(data.member.user_id, data.member.device_id, data.member.id);
+            }
+            case "session":
+                return `${matrixEvent.getSender()}:${data.device_id}`;
        }
    }

-    public get sender(): string | undefined {
-        return this.parentEvent.getSender();
+    public static async computeRtcIdentityRaw(userId: string, deviceId: string, memberId: string): Promise<string> {
+        const hashInput = `${userId}|${deviceId}|${memberId}`;
+        const hashBuffer = await sha256(hashInput);
+        const hashedString = encodeUnpaddedBase64Url(hashBuffer);
+        return hashedString;
    }

-    public get eventId(): string | undefined {
-        return this.parentEvent.getId();
+    public static membershipDataFromMatrixEvent(matrixEvent: MatrixEvent): MembershipData {
+        const [eventId, sender, content] = [matrixEvent.getId(), matrixEvent.getSender(), matrixEvent.getContent()];
+
+        if (eventId === undefined) throw new Error("parentEvent is missing eventId field");
+        if (sender === undefined) throw new Error("parentEvent is missing sender field");
+
+        const sessionErrors: string[] = [];
+        const rtcErrors: string[] = [];
+        if (checkSessionsMembershipData(content, sessionErrors)) {
+            return { kind: "session", data: content };
+        } else if (checkRtcMembershipData(content, rtcErrors, sender)) {
+            return { kind: "rtc", data: content };
+        } else {
+            const details =
+                sessionErrors.length < rtcErrors.length
+                    ? `Does not match MSC4143 m.call.member:\n${sessionErrors.join("\n")}\n\n`
+                    : `Does not match MSC4143 m.rtc.member:\n${rtcErrors.join("\n")}\n\n`;
+            const json = "\nevent:\n" + JSON.stringify(content).replaceAll('"', "'");
+            throw Error(`unknown CallMembership data.\n` + details + json);
+        }
    }

-    public get callId(): string {
-        return this.membershipData.call_id;
+    /** @deprecated use userId instead */
+    public get sender(): string {
+        return this.userId;
+    }
+    public get userId(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.user_id;
+            case "session":
+            default:
+                return this.matrixEventData.sender;
+        }
+    }
+
+    public get eventId(): string {
+        return this.matrixEventData.eventId;
+    }
+
+    /**
+     * The ID of the MatrixRTC slot that this membership belongs to (format `{application}#{id}`).
+     * This is computed in case SessionMembershipData is used.
+     */
+    public get slotId(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.slot_id;
+            case "session":
+            default:
+                return slotDescriptionToId({ application: this.application, id: data.call_id });
+        }
    }

    public get deviceId(): string {
-        return this.membershipData.device_id;
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.device_id;
+            case "session":
+            default:
+                return data.device_id;
+        }
    }

-    public get application(): string | undefined {
-        return this.membershipData.application;
+    public get callIntent(): RTCCallIntent | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc": {
+                const intent = data.application["m.call.intent"];
+                if (typeof intent === "string") {
+                    return intent;
+                }
+                this.logger?.warn("RTC membership has invalid m.call.intent");
+                return undefined;
+            }
+            case "session":
+            default:
+                return data["m.call.intent"];
+        }
    }

+    /**
+     * Parsed `slot_id` (format `{application}#{id}`) into its components (application and id).
+     */
+    public get slotDescription(): SlotDescription {
+        return slotIdToDescription(this.slotId);
+    }
+
+    public get application(): string {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.application.type;
+            case "session":
+            default:
+                return data.application;
+        }
+    }
+    public get applicationData(): { type: string; [key: string]: unknown } {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.application;
+            case "session":
+            default:
+                return { "type": data.application, "m.call.intent": data["m.call.intent"] };
+        }
+    }
+
+    /** @deprecated scope is not used and will be removed in future versions. replaced by application specific types.*/
    public get scope(): CallScope | undefined {
-        return this.membershipData.scope;
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                return data.scope;
+        }
+    }
+    /**
+     * @deprecated renamed to `memberId`
+     */
+    public get membershipID(): string {
+        return this.memberId;
    }

-    public get membershipID(): string {
+    /**
+     * This computes the membership ID for the membership.
+     * For the sticky event based rtcSessionData this is trivial it is `member.id`.
+     * This is not supposed to be used to identity on an rtc backend. This is just a nouance for
+     * a generated (sha256) anonymised identity. Only send `rtcBackendIdentity` to any rtc backend service.
+     *
+     * For the legacy sessionMemberEvents it is a bit more complex. Here we sometimes do not have this data
+     * in the event content and we expected the SFU and the client to use `${this.matrixEventData.sender}:${data.device_id}`.
+     *
+     * So if there is no membershipID we use the hard coded jwt id default (`${this.matrixEventData.sender}:${data.device_id}`)
+     * value (used until version 0.16.0)
+     *
+     * It is also possible for a session event to set a custom membershipID. in that case this will be used.
+     */
+    public get memberId(): string {
        // the createdTs behaves equivalent to the membershipID.
-        // we only need the field for the legacy member envents where we needed to update them
+        // we only need the field for the legacy member events where we needed to update them
        // synapse ignores sending state events if they have the same content.
-        return this.createdTs().toString();
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.member.id;
+            case "session":
+            default:
+                return (
+                    // best case we have a client already publishing the right custom membershipId
+                    data.membershipID ??
+                    // alternativly we use the hard coded jwt id defuatl value (used until version 0.16.0)
+                    `${this.matrixEventData.sender}:${data.device_id}`
+                );
+        }
    }

    public createdTs(): number {
-        return this.membershipData.created_ts ?? this.parentEvent.getTs();
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                // TODO we need to read the referenced (relation) event if available to get the real created_ts
+                return this.matrixEventData.ts;
+            case "session":
+            default:
+                return data.created_ts ?? this.matrixEventData.ts;
+        }
    }

    /**
     * Gets the absolute expiry timestamp of the membership.
     * @returns The absolute expiry time of the membership as a unix timestamp in milliseconds or undefined if not applicable
     */
-    public getAbsoluteExpiry(): number {
-        // TODO: calculate this from the MatrixRTCSession join configuration directly
-        return this.createdTs() + (this.membershipData.expires ?? DEFAULT_EXPIRE_DURATION);
+    public getAbsoluteExpiry(): number | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                // TODO: calculate this from the MatrixRTCSession join configuration directly
+                return this.createdTs() + (data.expires ?? DEFAULT_EXPIRE_DURATION);
+        }
    }

    /**
     * @returns The number of milliseconds until the membership expires or undefined if applicable
     */
-    public getMsUntilExpiry(): number {
-        // Assume that local clock is sufficiently in sync with other clocks in the distributed system.
-        // We used to try and adjust for the local clock being skewed, but there are cases where this is not accurate.
-        // The current implementation allows for the local clock to be -infinity to +MatrixRTCSession.MEMBERSHIP_EXPIRY_TIME/2
-        return this.getAbsoluteExpiry() - Date.now();
+    public getMsUntilExpiry(): number | undefined {
+        const { kind } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return undefined;
+            case "session":
+            default:
+                // Assume that local clock is sufficiently in sync with other clocks in the distributed system.
+                // We used to try and adjust for the local clock being skewed, but there are cases where this is not accurate.
+                // The current implementation allows for the local clock to be -infinity to +MatrixRTCSession.MEMBERSHIP_EXPIRY_TIME/2
+                return this.getAbsoluteExpiry()! - Date.now();
+        }
    }

    /**
     * @returns true if the membership has expired, otherwise false
     */
    public isExpired(): boolean {
-        return this.getMsUntilExpiry() <= 0;
-    }
-
-    public getPreferredFoci(): Focus[] {
-        return this.membershipData.foci_preferred;
-    }
-
-    public getFocusSelection(): string | undefined {
-        const focusActive = this.membershipData.focus_active;
-        if (isLivekitFocusActive(focusActive)) {
-            return focusActive.focus_selection;
+        const { kind } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return false;
+            case "session":
+            default:
+                return this.getMsUntilExpiry()! <= 0;
        }
    }
+
+    /**
+     * ## RTC Membership
+     * Gets the primary transport to use for this RTC membership (m.rtc.member).
+     * This will return the primary transport that is used by this call membership to publish their media.
+     * Directly relates to the `rtc_transports` field.
+     *
+     * ## Legacy session membership
+     * In case of a legacy session membership (m.call.member) this will return the selected transport where
+     * media is published. How this selection happens depends on the `focus_active` field of the session membership.
+     * If the `focus_selection` is `oldest_membership` this will return the transport of the oldest membership
+     * in the room (based on the `created_ts` field of the session membership).
+     * If the `focus_selection` is `multi_sfu` it will return the first transport of the `foci_preferred` list.
+     * (`multi_sfu` is equivalent to how `m.rtc.member` `rtc_transports` work).
+     * @param oldestMembership For backwards compatibility with session membership (legacy). Unused in case of RTC membership.
+     * Always required to make the consumer not care if it deals with RTC or session memberships.
+     * @returns The transport this membership uses to publish media or undefined if no transport is available.
+     */
+    public getTransport(oldestMembership: CallMembership): Transport | undefined {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.rtc_transports[0];
+            case "session":
+                switch (data.focus_active.focus_selection) {
+                    case "multi_sfu":
+                        return data.foci_preferred[0];
+                    case "oldest_membership":
+                        if (CallMembership.equal(this, oldestMembership)) return data.foci_preferred[0];
+                        if (oldestMembership !== undefined) return oldestMembership.getTransport(oldestMembership);
+                        break;
+                }
+        }
+        return undefined;
+    }
+
+    /**
+     * The focus_active filed of the session membership (m.call.member).
+     * @deprecated focus_active is not used and will be removed in future versions.
+     */
+    public getFocusActive(): LivekitFocusSelection | undefined {
+        const { kind, data } = this.membershipData;
+        if (kind === "session") return data.focus_active;
+        return undefined;
+    }
+    /**
+     * The value of the `rtc_transports` field for RTC memberships (m.rtc.member).
+     * Or the value of the `foci_preferred` field for legacy session memberships (m.call.member).
+     */
+    public get transports(): Transport[] {
+        const { kind, data } = this.membershipData;
+        switch (kind) {
+            case "rtc":
+                return data.rtc_transports;
+            case "session":
+            default:
+                return data.foci_preferred;
+        }
+    }
+    public get kind(): MembershipData["kind"] {
+        return this.membershipData.kind;
+    }
 }
@@ -5,13 +5,15 @@ import { decodeBase64, encodeUnpaddedBase64 } from "../base64.ts";
 import { safeGetRetryAfterMs } from "../http-api/errors.ts";
 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";
+import { isMyMembership, type EncryptionKeyMapKey, type Statistics } from "./types.ts";
+
+/**
+ * The string used for the keys in the the encryption key map.
+ * `@bob:examle.org:DEVICEID(UUIDRANDOM_MEMBERID_RANDOMUUID)`
+ */
+export function getEncryptionKeyMapKey(membership: CallMembershipIdentityParts): EncryptionKeyMapKey {
+    return `${membership.userId}:${membership.deviceId}(${membership.memberId})`;
+}

 /**
 * This interface is for testing and for making it possible to interchange the encryption manager.
@@ -43,9 +45,19 @@ export interface IEncryptionManager {
     *
     * @returns A map of participant IDs to their encryption keys.
     */
-    getEncryptionKeys(): ReadonlyMap<ParticipantId, ReadonlyArray<{ key: Uint8Array; keyIndex: number }>>;
+    getEncryptionKeys(): ReadonlyMap<
+        EncryptionKeyMapKey,
+        ReadonlyArray<{
+            key: Uint8Array<ArrayBuffer>;
+            keyIndex: number;
+            membership: CallMembershipIdentityParts;
+            rtcBackendIdentity: string;
+        }>
+    >;
 }

+export type CallMembershipIdentityParts = Pick<CallMembership, "userId" | "deviceId" | "memberId">;
+
 /**
 * This class implements the IEncryptionManager interface,
 * and takes care of managing the encryption keys of all rtc members:
@@ -72,7 +84,10 @@ export class EncryptionManager implements IEncryptionManager {
        return this.joinConfig?.useKeyDelay ?? 5_000;
    }

-    private encryptionKeys = new Map<string, Array<{ key: Uint8Array; timestamp: number }>>();
+    private encryptionKeys = new Map<
+        string,
+        Array<{ key: Uint8Array<ArrayBuffer>; timestamp: number; membership: CallMembershipIdentityParts }>
+    >();
    private lastEncryptionKeyUpdateRequest?: number;

    // We use this to store the last membership fingerprints we saw, so we can proactively re-send encryption keys
@@ -84,29 +99,52 @@ export class EncryptionManager implements IEncryptionManager {
    private logger: Logger;

    public constructor(
-        private userId: string,
-        private deviceId: string,
+        private membership: CallMembershipIdentityParts,
        private getMemberships: () => CallMembership[],
        private transport: IKeyTransport,
        private statistics: Statistics,
        private onEncryptionKeysChanged: (
-            keyBin: Uint8Array,
+            keyBin: Uint8Array<ArrayBuffer>,
            encryptionKeyIndex: number,
-            participantId: string,
+            membership: CallMembershipIdentityParts,
+            rtcBackendIdentity: string,
        ) => void,
        parentLogger?: Logger,
    ) {
        this.logger = (parentLogger ?? rootLogger).getChild(`[EncryptionManager]`);
    }

-    public getEncryptionKeys(): ReadonlyMap<ParticipantId, ReadonlyArray<{ key: Uint8Array; keyIndex: number }>> {
-        const keysMap = new Map<ParticipantId, ReadonlyArray<{ key: Uint8Array; keyIndex: number }>>();
-        for (const [userId, userKeys] of this.encryptionKeys) {
-            const keys = userKeys.map((entry, index) => ({
+    private rtcBackendIdentityFromMembershipParts(membership: CallMembershipIdentityParts): string {
+        // Implement logic to construct rtcBackendIdentity from membership parts
+        return `${membership.userId}:${membership.deviceId}`;
+    }
+
+    public getEncryptionKeys(): ReadonlyMap<
+        EncryptionKeyMapKey,
+        ReadonlyArray<{
+            key: Uint8Array<ArrayBuffer>;
+            keyIndex: number;
+            membership: CallMembershipIdentityParts;
+            rtcBackendIdentity: string;
+        }>
+    > {
+        const keysMap = new Map<
+            EncryptionKeyMapKey,
+            ReadonlyArray<{
+                key: Uint8Array<ArrayBuffer>;
+                keyIndex: number;
+                membership: CallMembershipIdentityParts;
+                rtcBackendIdentity: string;
+            }>
+        >();
+        for (const [userId, userKeyEntry] of this.encryptionKeys) {
+            const keys = userKeyEntry.map((entry, index) => ({
                key: entry.key,
+                membership: entry.membership,
                keyIndex: index,
+                rtcBackendIdentity: this.rtcBackendIdentityFromMembershipParts(entry.membership),
            }));
-            keysMap.set(userId as ParticipantId, keys);
+            keysMap.set(userId as EncryptionKeyMapKey, keys);
        }
        return keysMap;
    }
@@ -119,10 +157,7 @@ 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();
@@ -134,7 +169,7 @@ export class EncryptionManager implements IEncryptionManager {
        // clear our encryption keys as we're done with them now (we'll
        // make new keys if we rejoin). We leave keys for other participants
        // as they may still be using the same ones.
-        this.encryptionKeys.set(getParticipantId(this.userId, this.deviceId), []);
+        this.encryptionKeys.set(getEncryptionKeyMapKey(this.membership), []);
        this.transport.off(KeyTransportEvents.ReceivedKeys, this.onNewKeyReceived);
        this.transport.stop();

@@ -155,13 +190,13 @@ export class EncryptionManager implements IEncryptionManager {
        if (this.manageMediaKeys && this.joined) {
            const oldMembershipIds = new Set(
                oldMemberships
-                    .filter((m) => !isMyMembership(m, this.userId, this.deviceId))
-                    .map(getParticipantIdFromMembership),
+                    .filter((m) => !isMyMembership(m, this.membership.userId, this.membership.deviceId))
+                    .map(getEncryptionKeyMapKey),
            );
            const newMembershipIds = new Set(
                this.getMemberships()
-                    .filter((m) => !isMyMembership(m, this.userId, this.deviceId))
-                    .map(getParticipantIdFromMembership),
+                    .filter((m) => !isMyMembership(m, this.membership.userId, this.membership.deviceId))
+                    .map(getEncryptionKeyMapKey),
            );

            // We can use https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/symmetricDifference
@@ -210,14 +245,7 @@ export class EncryptionManager implements IEncryptionManager {
        const encryptionKey = secureRandomBase64Url(16);
        const encryptionKeyIndex = this.getNewEncryptionKeyIndex();
        this.logger.info("Generated new key at index " + encryptionKeyIndex);
-        this.setEncryptionKey(
-            this.userId,
-            this.deviceId,
-            encryptionKeyIndex,
-            encryptionKey,
-            Date.now(),
-            delayBeforeUse,
-        );
+        this.setEncryptionKey(this.membership, encryptionKeyIndex, encryptionKey, Date.now(), delayBeforeUse);
        return encryptionKeyIndex;
    }

@@ -248,12 +276,11 @@ export class EncryptionManager implements IEncryptionManager {
    /**
     * Get the known encryption keys for a given participant device.
     *
-     * @param userId the user ID of the participant
-     * @param deviceId the device ID of the participant
+     * @param membership - The membership identity parts of the participant
     * @returns The encryption keys for the given participant, or undefined if they are not known.
     */
-    private getKeysForParticipant(userId: string, deviceId: string): Array<Uint8Array> | undefined {
-        return this.encryptionKeys.get(getParticipantId(userId, deviceId))?.map((entry) => entry.key);
+    private getKeysForParticipant(membership: CallMembershipIdentityParts): Array<Uint8Array<ArrayBuffer>> | undefined {
+        return this.encryptionKeys.get(getEncryptionKeyMapKey(membership))?.map((entry) => entry.key);
    }

    /**
@@ -268,7 +295,7 @@ export class EncryptionManager implements IEncryptionManager {

        if (!this.joined) return;

-        const myKeys = this.getKeysForParticipant(this.userId, this.deviceId);
+        const myKeys = this.getKeysForParticipant(this.membership);

        if (!myKeys) {
            this.logger.warn("Tried to send encryption keys event but no keys found!");
@@ -302,7 +329,7 @@ export class EncryptionManager implements IEncryptionManager {
                });
            await this.transport.sendKey(encodeUnpaddedBase64(keyToSend), keyIndexToSend, targets);
            this.logger.debug(
-                `sendEncryptionKeysEvent participantId=${this.userId}:${this.deviceId} numKeys=${myKeys.length} currentKeyIndex=${this.latestGeneratedKeyIndex} keyIndexToSend=${keyIndexToSend}`,
+                `sendEncryptionKeysEvent participantId=${this.membership.userId}:${this.membership.deviceId} numKeys=${myKeys.length} currentKeyIndex=${this.latestGeneratedKeyIndex} keyIndexToSend=${keyIndexToSend}`,
            );
        } catch (error) {
            if (this.keysEventUpdateTimeout === undefined) {
@@ -315,20 +342,18 @@ 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);
+    public onNewKeyReceived: KeyTransportEventListener = (membership, keyBase64Encoded, index, timestamp) => {
+        this.logger.debug(
+            `Received key over key transport ${membership.userId}:${membership.deviceId} at index ${index}`,
+        );
+        this.setEncryptionKey(membership, index, keyBase64Encoded, timestamp);
    };

    private storeLastMembershipFingerprints(): void {
        this.lastMembershipFingerprints = new Set(
            this.getMemberships()
-                .filter((m) => !isMyMembership(m, this.userId, this.deviceId))
-                .map((m) => `${getParticipantIdFromMembership(m)}:${m.createdTs()}`),
+                .filter((m) => !isMyMembership(m, this.membership.userId, this.membership.deviceId))
+                .map((m) => `${getEncryptionKeyMapKey(m)}:${m.createdTs()}`),
        );
    }

@@ -356,28 +381,29 @@ export class EncryptionManager implements IEncryptionManager {
     *                         be distributed.
     */
    private setEncryptionKey(
-        userId: string,
-        deviceId: string,
+        membership: CallMembershipIdentityParts,
        encryptionKeyIndex: number,
        encryptionKeyString: string,
        timestamp: number,
        delayBeforeUse = false,
    ): void {
-        this.logger.debug(`Setting encryption key for ${userId}:${deviceId} at index ${encryptionKeyIndex}`);
+        this.logger.debug(
+            `Setting encryption key for ${membership.userId}:${membership.deviceId} at index ${encryptionKeyIndex}`,
+        );
        const keyBin = decodeBase64(encryptionKeyString);

-        const participantId = getParticipantId(userId, deviceId);
-        if (!this.encryptionKeys.has(participantId)) {
-            this.encryptionKeys.set(participantId, []);
+        const mapKey = getEncryptionKeyMapKey(membership);
+        if (!this.encryptionKeys.has(mapKey)) {
+            this.encryptionKeys.set(mapKey, []);
        }
-        const participantKeys = this.encryptionKeys.get(participantId)!;
+        const participantKeys = this.encryptionKeys.get(mapKey)!;

        const existingKeyAtIndex = participantKeys[encryptionKeyIndex];

        if (existingKeyAtIndex) {
            if (existingKeyAtIndex.timestamp > timestamp) {
                this.logger.info(
-                    `Ignoring new key at index ${encryptionKeyIndex} for ${participantId} as it is older than existing known key`,
+                    `Ignoring new key at index ${encryptionKeyIndex} for ${mapKey} as it is older than existing known key`,
                );
                return;
            }
@@ -388,7 +414,7 @@ export class EncryptionManager implements IEncryptionManager {
            }
        }

-        if (userId === this.userId && deviceId === this.deviceId) {
+        if (membership.userId === this.membership.userId && membership.deviceId === this.membership.deviceId) {
            // It is important to already update the latestGeneratedKeyIndex here
            // NOT IN THE `delayBeforeUse` `setTimeout`.
            // Even though this is where we call onEncryptionKeysChanged and set the key in EC (and livekit).
@@ -400,18 +426,29 @@ export class EncryptionManager implements IEncryptionManager {
        participantKeys[encryptionKeyIndex] = {
            key: keyBin,
            timestamp,
+            membership: membership,
        };

        if (delayBeforeUse) {
            const useKeyTimeout = setTimeout(() => {
                this.setNewKeyTimeouts.delete(useKeyTimeout);
-                this.logger.info(`Delayed-emitting key changed event for ${participantId} index ${encryptionKeyIndex}`);
+                this.logger.info(`Delayed-emitting key changed event for ${mapKey} index ${encryptionKeyIndex}`);

-                this.onEncryptionKeysChanged(keyBin, encryptionKeyIndex, participantId);
+                this.onEncryptionKeysChanged(
+                    keyBin,
+                    encryptionKeyIndex,
+                    membership,
+                    this.rtcBackendIdentityFromMembershipParts(membership),
+                );
            }, this.useKeyDelay);
            this.setNewKeyTimeouts.add(useKeyTimeout);
        } else {
-            this.onEncryptionKeysChanged(keyBin, encryptionKeyIndex, participantId);
+            this.onEncryptionKeysChanged(
+                keyBin,
+                encryptionKeyIndex,
+                membership,
+                this.rtcBackendIdentityFromMembershipParts(membership),
+            );
        }
    }

@@ -431,5 +468,3 @@ function keysEqual(a: Uint8Array | undefined, b: Uint8Array | undefined): boolea
    if (a === b) return true;
    return !!a && !!b && a.length === b.length && a.every((x, i) => x === b[i]);
 }
-
-const getParticipantIdFromMembership = (m: CallMembership): string => getParticipantId(m.sender!, m.deviceId);
@@ -14,6 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

+import { type CallMembershipIdentityParts } from "./EncryptionManager.ts";
 import { type ParticipantDeviceInfo } from "./types.ts";

 export enum KeyTransportEvents {
@@ -27,8 +28,7 @@ export type KeyTransportEventsHandlerMap = {
 };

 export type KeyTransportEventListener = (
-    userId: string,
-    deviceId: string,
+    membership: CallMembershipIdentityParts,
    keyBase64Encoded: string,
    index: number,
    timestamp: number,
@@ -15,15 +15,28 @@ limitations under the License.
 */

 import type { CallMembership } from "./CallMembership.ts";
-import type { Focus } from "./focus.ts";
-import type { Status } from "./types.ts";
+import type { RTCCallIntent, Status, Transport } from "./types.ts";
+import { type TypedEventEmitter } from "../models/typed-event-emitter.ts";

 export enum MembershipManagerEvent {
    StatusChanged = "StatusChanged",
+    /**
+     * Emitted when the membership manager has not heard back from the server for the duration
+     * of the delayed event and hence failed to restart the delayed event.
+     * This means that the user is probably not joined anymore and the leave event was distributed to other session members.
+     */
+    ProbablyLeft = "ProbablyLeft",
+    /**
+     * Once the membershipManger has aquired the a delay id (after sending the state event)
+     * It will emit and share the delay id.
+     */
+    DelayIdChanged = "DelayIdChanged",
 }

 export type MembershipManagerEventHandlerMap = {
    [MembershipManagerEvent.StatusChanged]: (prefStatus: Status, newStatus: Status) => void;
+    [MembershipManagerEvent.ProbablyLeft]: (probablyLeft: boolean) => void;
+    [MembershipManagerEvent.DelayIdChanged]: (delayId: string | undefined) => void;
 };

 /**
@@ -33,7 +46,10 @@ export type MembershipManagerEventHandlerMap = {
 *
 * @internal
 */
-export interface IMembershipManager {
+export interface IMembershipManager extends TypedEventEmitter<
+    MembershipManagerEvent,
+    MembershipManagerEventHandlerMap
+> {
    /**
     * If we are trying to join, or have successfully joined the session.
     * It does not reflect if the room state is already configured to represent us being joined.
@@ -62,13 +78,28 @@ export interface IMembershipManager {
     */
    get ownMembership(): CallMembership | undefined;

+    /**
+     * If the membership manager has reason to believe that the hs sent a leave event
+     * and as a consequence the current user is perceived as left for other session participants.
+     */
+    get probablyLeft(): boolean;
+
+    /**
+     * If the membership manager has reason to believe that the hs sent a leave event
+     * and as a consequence the current user is perceived as left for other session participants.
+     */
+    get delayId(): string | undefined;
+
    /**
     * Start sending all necessary events to make this user participate in the RTC session.
     * @param fociPreferred the list of preferred foci to use in the joined RTC membership event.
-     * @param fociActive the active focus to use in the joined RTC membership event.
+     * If multiSfuFocus is set, this is only needed if this client wants to publish to multiple transports simultaneously.
+     * @param multiSfuFocus the active focus to use in the joined RTC membership event. Setting this implies the
+     * membership manager will operate in a multi-SFU connection mode. If `undefined`, an `oldest_membership`
+     * transport selection will be used instead.
     * @throws can throw if it exceeds a configured maximum retry.
     */
-    join(fociPreferred: Focus[], fociActive?: Focus, onError?: (error: unknown) => void): void;
+    join(fociPreferred: Transport[], multiSfuFocus?: Transport, onError?: (error: unknown) => void): void;
    /**
     * Send all necessary events to make this user leave the RTC session.
     * @param timeout the maximum duration in ms until the promise is forced to resolve.
@@ -80,13 +111,10 @@ export interface IMembershipManager {
     * Call this if the MatrixRTC session members have changed.
     */
    onRTCSessionMemberUpdate(memberships: CallMembership[]): Promise<void>;
-    /**
-     * The used active focus in the currently joined session.
-     * @returns the used active focus in the currently joined session or undefined if not joined.
-     */
-    getActiveFocus(): Focus | undefined;

-    // TypedEventEmitter methods:
-    on(event: MembershipManagerEvent.StatusChanged, listener: (oldStatus: Status, newStatus: Status) => void): this;
-    off(event: MembershipManagerEvent.StatusChanged, listener: (oldStatus: Status, newStatus: Status) => void): this;
+    /**
+     * Update the intent of a membership on the call (e.g. user is now providing a video feed)
+     * @param callIntent The new intent to set.
+     */
+    updateCallIntent(callIntent: RTCCallIntent): Promise<void>;
 }
@@ -1,39 +0,0 @@
-/*
-Copyright 2023 New Vector Ltd
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import { type Focus } from "./focus.ts";
-
-export interface LivekitFocusConfig extends Focus {
-    type: "livekit";
-    livekit_service_url: string;
-}
-
-export const isLivekitFocusConfig = (object: any): object is LivekitFocusConfig =>
-    object.type === "livekit" && "livekit_service_url" in object;
-
-export interface LivekitFocus extends LivekitFocusConfig {
-    livekit_alias: string;
-}
-
-export const isLivekitFocus = (object: any): object is LivekitFocus =>
-    isLivekitFocusConfig(object) && "livekit_alias" in object;
-
-export interface LivekitFocusActive extends Focus {
-    type: "livekit";
-    focus_selection: "oldest_membership";
-}
-export const isLivekitFocusActive = (object: any): object is LivekitFocusActive =>
-    object.type === "livekit" && "focus_selection" in object;
@@ -0,0 +1,46 @@
+/*
+Copyright 2025 New Vector Ltd
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { type Transport } from "./types.ts";
+
+export interface LivekitTransportConfig extends Transport {
+    type: "livekit";
+    livekit_service_url: string;
+}
+
+export const isLivekitTransportConfig = (object: any): object is LivekitTransportConfig =>
+    object.type === "livekit" && "livekit_service_url" in object;
+
+export interface LivekitTransport extends LivekitTransportConfig {
+    livekit_alias: string;
+}
+
+export const isLivekitTransport = (object: any): object is LivekitTransport =>
+    isLivekitTransportConfig(object) && "livekit_alias" in object;
+
+/**
+ * @deprecated, this is just needed for the old focus active / focus fields of a call membership.
+ * Not needed for new implementations.
+ */
+export interface LivekitFocusSelection extends Transport {
+    type: "livekit";
+    focus_selection: "oldest_membership" | "multi_sfu";
+}
+/**
+ * @deprecated see LivekitFocusSelection
+ */
+export const isLivekitFocusSelection = (object: any): object is LivekitFocusSelection =>
+    object.type === "livekit" && "focus_selection" in object;
--- a/Show More
+++ b/Show More