Remove dependency on uuid (#5297 )

Update dependency vite to v8 (#5295 )
* Update dependency vite to v8 * Update lockfile --------- Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com> Co-authored-by: Michael Telatynski <7t3chguy@gmail.com>
2026-04-23 09:53:18 +00:00 · 2026-04-22 16:16:29 +00:00 · 2026-04-22 09:10:39 +00:00 · 2026-04-21 14:38:05 +00:00 · 2026-04-21 13:58:22 +00:00 · 2026-04-21 12:37:38 +00:00
276 changed files with 26383 additions and 15671 deletions
@@ -1,6 +1,6 @@
 module.exports = {
-    plugins: ["matrix-org", "import", "jsdoc", "n"],
-    extends: ["plugin:matrix-org/babel", "plugin:matrix-org/jest", "plugin:import/typescript"],
+    plugins: ["matrix-org", "import", "jsdoc", "n", "@vitest"],
+    extends: ["plugin:matrix-org/babel", "plugin:import/typescript"],
    parserOptions: {
        project: ["./tsconfig.json"],
    },
@@ -83,16 +83,6 @@ module.exports = {
                ],
            },
        ],
-        // Disabled tests are a reality for now but as soon as all of the xits are
-        // eliminated, we should enforce this.
-        "jest/no-disabled-tests": "off",
-        // Used in some crypto tests.
-        "jest/no-standalone-expect": [
-            "error",
-            {
-                additionalTestBlockFunctions: ["beforeAll", "beforeEach"],
-            },
-        ],
    },
    overrides: [
        {
@@ -147,11 +137,37 @@ module.exports = {
        },
        {
            files: ["spec/**/*.ts"],
+            extends: ["plugin:@vitest/legacy-recommended"],
            rules: {
                // We don't need super strict typing in test utilities
                "@typescript-eslint/explicit-function-return-type": "off",
                "@typescript-eslint/explicit-member-accessibility": "off",
                "@typescript-eslint/no-empty-object-type": "off",
+
+                // Disabled tests are a reality for now but as soon as all of the xits are
+                // eliminated, we should enforce this.
+                "@vitest/no-disabled-tests": "off",
+                // Used in some crypto tests.
+                "@vitest/no-standalone-expect": [
+                    "error",
+                    {
+                        additionalTestBlockFunctions: ["beforeAll", "beforeEach"],
+                    },
+                ],
+                "@vitest/expect-expect": [
+                    "error",
+                    {
+                        assertFunctionNames: [
+                            "expect",
+                            "expectDevices",
+                            "assert.isTrue",
+                            "assert.isFalse",
+                            "passwordTest",
+                            "compareHeaders",
+                            "doTest",
+                        ],
+                    },
+                ],
            },
        },
        {
@@ -1,7 +1,7 @@
 *                         @matrix-org/element-web-reviewers
 /.github/workflows/**     @matrix-org/element-web-team
 /package.json             @matrix-org/element-web-team
-/yarn.lock                @matrix-org/element-web-team
+/pnpm-lock.yaml           @matrix-org/element-web-team
 /scripts/**               @matrix-org/element-web-team
 /src/webrtc               @matrix-org/element-call-reviewers
 /src/matrixrtc               @matrix-org/element-call-reviewers
@@ -22,7 +22,7 @@ runs:

        - name: Upload tarball signature
          if: ${{ inputs.upload-url }}
-          uses: shogo82148/actions-upload-release-asset@d22998fda4c1407f60d1ab48cd6fe67f360f34de # v1
+          uses: shogo82148/actions-upload-release-asset@96bc1f0cb850b65efd58a6b5eaa0a69f88d38077 # 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@d22998fda4c1407f60d1ab48cd6fe67f360f34de # v1
+          uses: shogo82148/actions-upload-release-asset@96bc1f0cb850b65efd58a6b5eaa0a69f88d38077 # v1
          with:
              upload_url: ${{ inputs.upload-url }}
              asset_path: ${{ inputs.asset-path }}.asc

        - name: Upload assets
-          uses: shogo82148/actions-upload-release-asset@d22998fda4c1407f60d1ab48cd6fe67f360f34de # v1
+          uses: shogo82148/actions-upload-release-asset@96bc1f0cb850b65efd58a6b5eaa0a69f88d38077 # 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"
@@ -1,6 +1,8 @@
 name: Backport
 on:
-    pull_request_target:
+    # Privilege escalation necessary to enable backporting PRs from forks
+    # 🚨 We must not execute any checked out code here.
+    pull_request_target: # zizmor: ignore[dangerous-triggers]
        types:
            - closed
            - labeled
@@ -1,7 +1,9 @@
 name: Deploy documentation PR preview

 on:
-    workflow_run:
+    # Privilege escalation necessary to publish to Netlify
+    # 🚨 We must not execute any checked out code here.
+    workflow_run: # zizmor: ignore[dangerous-triggers]
        workflows: ["Static Analysis"]
        types:
            - completed
@@ -15,7 +17,7 @@ jobs:
            deployments: write
        steps:
            - name: 📥 Download artifact
-              uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
                  run-id: ${{ github.event.workflow_run.id }}
@@ -1,7 +1,7 @@
 # Triggers after the "Downstream artifacts" build has finished, to run the
-# matrix-react-sdk playwright tests (with access to repo secrets)
+# element-web playwright tests (with access to repo secrets)

-name: matrix-react-sdk End to End Tests
+name: Element Web End to End Tests
 on:
    merge_group:
        types: [checks_requested]
@@ -21,11 +21,12 @@ concurrency:
 jobs:
    playwright:
        name: Playwright
-        uses: element-hq/element-web/.github/workflows/end-to-end-tests.yaml@develop
+        uses: element-hq/element-web/.github/workflows/build-and-test.yaml@develop # zizmor: ignore[unpinned-uses]
        permissions:
            actions: read
            issues: read
            pull-requests: read
+            contents: read
        with:
            matrix-js-sdk-sha: ${{ github.sha }}
            # We only want to run the playwright tests on merge queue to prevent regressions
@@ -18,8 +18,8 @@ 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
+            - name: Notify element-web repo that a new SDK build is on develop so it can CI against it
+              uses: peter-evans/repository-dispatch@28959ce8df70de7be546dd1250a005dd32156697 # v4
              with:
                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                  repository: ${{ matrix.repo }}
@@ -1,6 +1,9 @@
 name: Pull Request
 on:
-    pull_request_target:
+    # Privilege escalation necessary access members of the review teams
+    # 🚨 We must not execute any checked out code here, and be careful around use of user-controlled inputs.
+    # FIXME: only `community-prs` job needs this privilege, so it should be in its own workflow file.
+    pull_request_target: # zizmor: ignore[dangerous-triggers]
        types: [opened, edited, labeled, unlabeled, synchronize]
    merge_group:
        types: [checks_requested]
@@ -15,7 +18,7 @@ jobs:
        name: Preview Changelog
        runs-on: ubuntu-24.04
        steps:
-            - uses: mheap/github-action-required-labels@388fd6af37b34cdfe5a23b37060e763217e58b03 # v5
+            - uses: mheap/github-action-required-labels@0ac283b4e65c1fb28ce6079dea5546ceca98ccbe # v5
              if: github.event_name != 'merge_group'
              with:
                  labels: |
@@ -35,7 +38,7 @@ jobs:
            pull-requests: read
        steps:
            - name: Add notice
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              if: contains(github.event.pull_request.labels.*.name, 'X-Blocked')
              with:
                  script: |
@@ -49,7 +52,7 @@ 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 +63,7 @@ jobs:

            - name: Add label
              if: steps.teams.outputs.isTeamMember == 'false'
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              with:
                  script: |
                      github.rest.issues.addLabels({
@@ -73,13 +76,15 @@ 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@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              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@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              env:
                  REPO: ${{ inputs.repository }}
              with:
@@ -16,18 +16,20 @@ jobs:
            contents: write
        steps:
            - name: 🧮 Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  ref: staging
                  fetch-depth: 0
+                  persist-credentials: false

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
                  node-version-file: package.json
-                  cache: "yarn"
+                  cache: "pnpm"

            - name: Install Deps
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - uses: t3chguy/release-drafter@105e541c2c3d857f032bd522c0764694758fabad
              id: draft-release
@@ -37,7 +39,7 @@ jobs:
                  disable-autolabeler: true

            - name: Get actions scripts
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -48,7 +50,7 @@ jobs:

            - name: Ingest upstream changes
              if: inputs.include-changes
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              env:
                  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
@@ -13,4 +13,4 @@ jobs:
    draft:
        permissions:
            contents: write
-        uses: matrix-org/matrix-js-sdk/.github/workflows/release-drafter-workflow.yml@develop
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-drafter-workflow.yml@develop # zizmor: ignore[unpinned-uses]
@@ -12,20 +12,25 @@ on:
                description: List of dependencies to reset.
                type: string
                required: false
+            dir:
+                description: The directory to release
+                type: string
+                default: "."
 concurrency: ${{ github.workflow }}
 permissions: {} # Uses ELEMENT_BOT_TOKEN
 jobs:
    merge:
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # 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
+                  persist-credentials: true

            - name: Get actions scripts
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -33,13 +38,14 @@ jobs:
                  sparse-checkout: |
                      scripts/release

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - name: Set up git
              run: |
@@ -53,6 +59,7 @@ jobs:

            - name: Reset dependencies
              if: inputs.dependencies
+              working-directory: ${{ inputs.dir }}
              run: |
                  while IFS= read -r PACKAGE; do
                      [ -z "$PACKAGE" ] && continue
@@ -73,7 +80,7 @@ jobs:
                      fi

                      echo "Resetting $PACKAGE to develop branch..."
-                      yarn add "github:matrix-org/$PACKAGE#develop"
+                      pnpm add "github:matrix-org/$PACKAGE#develop"
                      git add -u
                      git commit -m "Reset $PACKAGE back to develop branch"
                  done <<< "$DEPENDENCIES"
@@ -4,8 +4,6 @@ on:
        secrets:
            ELEMENT_BOT_TOKEN:
                required: true
-            NPM_TOKEN:
-                required: false
            GPG_PASSPHRASE:
                required: false
            GPG_PRIVATE_KEY:
@@ -28,12 +26,21 @@ on:
                description: |
                    The path to the asset you want to upload, if any. You can use glob patterns here.
                    Will be GPG signed and an `.asc` file included in the release artifacts if `gpg-fingerprint` is set.
+                    Relative to `dir`.
                type: string
                required: false
            expected-asset-count:
                description: The number of expected assets, including signatures, excluding generated zip & tarball.
                type: number
                required: false
+            dist-dir:
+                description: The directory to release
+                type: string
+                default: "."
+            version-dirs:
+                description: Directories in which to update package.json `version` field
+                type: string
+                required: false
        outputs:
            npm-id:
                description: "The npm package@version string we published"
@@ -45,7 +52,7 @@ jobs:
        permissions:
            issues: read
            pull-requests: read
-        uses: matrix-org/matrix-js-sdk/.github/workflows/release-checks.yml@develop
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-checks.yml@develop # zizmor: ignore[unpinned-uses]

    release:
        name: Release
@@ -58,7 +65,7 @@ jobs:
            - name: Load GPG key
              id: gpg
              if: inputs.gpg-fingerprint
-              uses: crazy-max/ghaction-import-gpg@e89d40939c28e39f97cf32126055eeae86ba74ec # v6
+              uses: crazy-max/ghaction-import-gpg@2dc316deee8e90f13e1a351ab510b4d5bc0c82cd # v7
              with:
                  gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
                  passphrase: ${{ secrets.GPG_PASSPHRASE }}
@@ -66,22 +73,23 @@ jobs:

            - name: Get draft release
              id: draft-release
-              uses: cardinalby/git-get-release-action@5172c3a026600b1d459b117738c605fabc9e4e44 # v1
+              uses: cardinalby/git-get-release-action@5172c3a026600b1d459b117738c605fabc9e4e44 # 1.2.5
              env:
                  GITHUB_TOKEN: ${{ github.token }}
              with:
                  draft: true
                  latest: true

-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # 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
                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
                  fetch-depth: 0
+                  persist-credentials: true

            - name: Get actions scripts
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  repository: matrix-org/matrix-js-sdk
                  persist-credentials: false
@@ -92,6 +100,7 @@ jobs:

            - name: Prepare variables
              id: prepare
+              working-directory: ${{ inputs.dist-dir }}
              run: |
                  echo "VERSION=$VERSION" >> $GITHUB_ENV

@@ -106,7 +115,7 @@ 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@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              with:
                  script: |
                      const { VERSION } = process.env;
@@ -125,15 +134,17 @@ jobs:
                  git config --global user.email "releases@riot.im"
                  git config --global user.name "RiotRobot"

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
-                  node-version-file: package.json
+                  cache: "pnpm"
+                  node-version-file: ${{ inputs.dist-dir }}/package.json

            - name: Install dependencies
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - name: Handle develop dependencies
+              working-directory: ${{ inputs.dist-dir }}
              run: |
                  ret=0
                  cat package.json | jq -r '.dependencies | to_entries | .[] | "\(.key) \(.value)"' | grep '#develop$' | while read -r dep ; do
@@ -142,15 +153,19 @@ jobs:
                      VERSION=${dep[1]}

                      echo "::warning title=Develop dependency found::$DEPENDENCY will be kept at $VERSION"
-                      yarn upgrade "$PACKAGE@$VERSION" --exact
+                      pnpm add "$PACKAGE@$VERSION" --save-exact
                      git add -u
                      git commit -m "Keep $PACKAGE at $VERSION"
                  done

-            - name: Bump package.json version
+            - name: Bump package.json versions
              run: |
-                  yarn version --no-git-tag-version --new-version "${VERSION#v}"
-                  git add package.json
+                  for DIR in $DIRS; do
+                      pnpm version -C "$DIR" --no-git-tag-version "${VERSION#v}"
+                      git add "$DIR"/package.json
+                  done
+              env:
+                  DIRS: ${{ inputs.version-dirs || inputs.dist-dir }}

            - name: Add to CHANGELOG.md
              if: inputs.final
@@ -177,7 +192,8 @@ jobs:

            - name: Build assets
              if: steps.prepare.outputs.has-dist-script == '1'
-              run: DIST_VERSION="$VERSION" yarn dist
+              working-directory: ${{ inputs.dist-dir }}
+              run: DIST_VERSION="$VERSION" pnpm dist

            - name: Upload release assets & signatures
              if: inputs.asset-path
@@ -185,7 +201,7 @@ jobs:
              with:
                  gpg-fingerprint: ${{ inputs.gpg-fingerprint }}
                  upload-url: ${{ steps.draft-release.outputs.upload_url }}
-                  asset-path: ${{ inputs.asset-path }}
+                  asset-path: ${{ inputs.dist-dir }}/${{ inputs.asset-path }}

            - name: Create signed tag
              if: inputs.gpg-fingerprint
@@ -218,7 +234,7 @@ jobs:

            - name: Validate release has expected assets
              if: inputs.expected-asset-count
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              env:
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  EXPECTED_ASSET_COUNT: ${{ inputs.expected-asset-count }}
@@ -246,7 +262,7 @@ jobs:
                  git push origin master

            - name: Publish release
-              uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7
+              uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9
              env:
                  RELEASE_ID: ${{ steps.draft-release.outputs.id }}
                  FINAL: ${{ inputs.final }}
@@ -278,12 +294,12 @@ jobs:
        name: Publish to npm
        needs: release
        if: inputs.npm
-        uses: matrix-org/matrix-js-sdk/.github/workflows/release-npm.yml@develop
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-npm.yml@develop # zizmor: ignore[unpinned-uses]
+        with:
+            dir: ${{ inputs.dist-dir }}
        permissions:
            contents: read
            id-token: write
-        secrets:
-            NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

    post-release:
        name: Post release steps
@@ -1,9 +1,11 @@
 name: Publish to npm
 on:
    workflow_call:
-        secrets:
-            NPM_TOKEN:
-                required: true
+        inputs:
+            dir:
+                description: The directory to release
+                type: string
+                default: "."
        outputs:
            id:
                description: "The npm package@version string we published"
@@ -20,32 +22,32 @@ jobs:
            id: ${{ steps.npm-publish.outputs.id }}
        steps:
            - name: 🧮 Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  ref: staging
+                  persist-credentials: false

-            - name: 🔧 Yarn cache
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - name: 🔧 pnpm cache
+              uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
+                  cache: "pnpm"
                  registry-url: "https://registry.npmjs.org"
-                  node-version-file: package.json
+                  node-version-file: ${{ inputs.dir }}/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"
+              run: "pnpm install --frozen-lockfile"

            - name: 🚀 Publish to npm
              id: npm-publish
+              working-directory: ${{ inputs.dir }}
              run: |
-                  npm publish --provenance --access public --tag next
+                  npm publish --provenance --access public --tag "$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' }}
@@ -24,7 +24,7 @@ concurrency: ${{ github.workflow }}
 permissions: {} # No permissions required
 jobs:
    release:
-        uses: matrix-org/matrix-js-sdk/.github/workflows/release-make.yml@develop
+        uses: matrix-org/matrix-js-sdk/.github/workflows/release-make.yml@develop # zizmor: ignore[unpinned-uses,secrets-inherit]
        permissions:
            contents: write
            issues: write
@@ -41,28 +41,32 @@ jobs:
        runs-on: ubuntu-24.04
        strategy:
            matrix:
-                repo:
-                    - element-hq/element-web
+                include:
+                    - repo: element-hq/element-web
+                      path: apps/web
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  repository: ${{ matrix.repo }}
                  ref: staging
                  token: ${{ secrets.ELEMENT_BOT_TOKEN }}
+                  persist-credentials: true

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
+                  cache: "pnpm"
                  node-version: "lts/*"

            - name: Bump dependency
              env:
                  DEPENDENCY: ${{ needs.release.outputs.npm-id }}
+                  DIR: ${{ matrix.path }}
              run: |
                  git config --global user.email "releases@riot.im"
                  git config --global user.name "RiotRobot"
-                  yarn upgrade "$DEPENDENCY" --exact
-                  git add package.json yarn.lock
+                  pnpm add -C "$DIR" "$DEPENDENCY" --save-exact
+                  git add "$DIR"/package.json pnpm-lock.yaml
                  git commit -am"Upgrade dependency to $DEPENDENCY"
                  git push origin staging

@@ -73,22 +77,25 @@ jobs:
        runs-on: ubuntu-24.04
        steps:
            - name: 🧮 Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - name: 🔧 Yarn cache
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - name: 🔧 pnpm cache
+              uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: 🔨 Install dependencies
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - name: 📖 Generate docs
-              run: yarn gendoc
+              run: pnpm gendoc

            - name: Upload artifact
-              uses: actions/upload-pages-artifact@56afc609e74202658d3ffba0e8f6dda462b719fa # v3
+              uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9 # v5
              with:
                  path: _docs

@@ -106,4 +113,4 @@ jobs:
        steps:
            - name: Deploy to GitHub Pages
              id: deployment
-              uses: actions/deploy-pages@d6db90164ac5ed86f2b6aed7e0febac5b3c0c03e # v4
+              uses: actions/deploy-pages@cd2ce8fcbc39b97be8ca5fce6e763baed58fa128 # v5
@@ -12,7 +12,11 @@ on:
            sharded:
                type: boolean
                required: false
-                description: "Whether to combine multiple LCOV and jest-sonar-report files in coverage artifact"
+                description: "Whether to combine multiple LCOV and sonar-report files in coverage artifact"
+            version-pkg-json-dir:
+                type: string
+                default: "."
+                description: "Relative path of the directory containing package.json with the `version` to use."
 permissions: {}
 jobs:
    sonarqube:
@@ -27,7 +31,7 @@ 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@5f2b01ce1394109f70954ae6b69ef41cf7928e63
+            - uses: guibranco/github-status-action-v2@9bfa8773cdbdc6c185747fd43cd7faa9d7c32f09
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
                  state: pending
@@ -36,14 +40,15 @@ jobs:
                  target_url: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}

            - name: "🧮 Checkout code"
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # 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
+                  persist-credentials: false

            - name: 📥 Download artifact
-              uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
              if: ${{ !inputs.sharded }}
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
@@ -51,14 +56,13 @@ jobs:
                  name: coverage
                  path: coverage
            - name: 📥 Download sharded artifacts
-              uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
+              uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8
              if: inputs.sharded
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
                  run-id: ${{ github.event.workflow_run.id }}
                  pattern: coverage-*
                  path: coverage
-                  merge-multiple: true
            - name: Check coverage artifact
              run: |
                  if [ ! -d coverage ]; then
@@ -75,19 +79,20 @@ jobs:

            - name: "🩻 SonarCloud Scan"
              id: sonarcloud
-              uses: matrix-org/sonarcloud-workflow-action@820f7c2e9e94ba9e35add0f739691e5c7e23fa25 # v4.0
+              uses: matrix-org/sonarcloud-workflow-action@13968a27c924fa19b1dacbce6ca3ff217daa775b
              # 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' }}
-                  version_cmd: "cat package.json | jq -r .version"
+                  skip_coverage_label: Z-Skip-Coverage
+                  version_cmd: "cat ${{ inputs.version-pkg-json-dir }}/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@5f2b01ce1394109f70954ae6b69ef41cf7928e63
+            - uses: guibranco/github-status-action-v2@9bfa8773cdbdc6c185747fd43cd7faa9d7c32f09
              if: always()
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
@@ -1,6 +1,8 @@
 name: SonarQube
 on:
-    workflow_run:
+    # Privilege escalation necessary to call upon SonarCloud
+    # 🚨 We must not execute any checked out code here.
+    workflow_run: # zizmor: ignore[dangerous-triggers]
        workflows: ["Tests"]
        types:
            - completed
@@ -16,7 +18,7 @@ jobs:
            actions: read
            statuses: write
            id-token: write # sonar
-        uses: matrix-org/matrix-js-sdk/.github/workflows/sonarcloud.yml@develop
+        uses: matrix-org/matrix-js-sdk/.github/workflows/sonarcloud.yml@develop # zizmor: ignore[unpinned-uses]
        secrets:
            SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
            ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
@@ -14,58 +14,61 @@ jobs:
        name: "Typescript Syntax Check"
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install"
+              run: "pnpm install"

            - name: Typecheck
-              run: "yarn run lint:types"
+              run: "pnpm run lint:types"

    js_lint:
        name: "ESLint"
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install"
+              run: "pnpm install"

            - name: Run Linter
-              run: "yarn run lint:js"
+              run: "pnpm run lint:js"

    node_example_lint:
        name: "Node.js example"
        runs-on: ubuntu-latest
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install"
+              run: "pnpm install"

            - name: Build Types
-              run: "yarn build:types"
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
-              with:
-                  cache: "npm"
-                  node-version-file: "examples/node/package.json"
-                  # cache-dependency-path: '**/package-lock.json'
+              run: "pnpm build:types"

            - name: Install Example Deps
              run: "npm install"
@@ -82,39 +85,50 @@ jobs:
    workflow_lint:
        name: "Workflow Lint"
        runs-on: ubuntu-24.04
+        permissions:
+            security-events: write
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - name: Run Linter
-              run: "yarn lint:workflows"
+              run: "pnpm lint:workflows"
+
+            - name: Run zizmor
+              uses: zizmorcore/zizmor-action@b1d7e1fb5de872772f31590499237e7cce841e8e # v0.5.3

    docs:
        name: "JSDoc Checker"
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install"
+              run: "pnpm install"

            - name: Generate Docs
-              run: "yarn run gendoc --treatWarningsAsErrors --suppressCommentWarningsInDeclarationFiles"
+              run: "pnpm run gendoc --treatWarningsAsErrors --suppressCommentWarningsInDeclarationFiles"

            - name: Upload Artifact
-              uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+              uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
              with:
                  name: docs
                  path: _docs
@@ -125,31 +139,36 @@ jobs:
        name: "Analyse Dead Code"
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
-
-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
-                  cache: "yarn"
+                  persist-credentials: false
+
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
+              with:
+                  cache: "pnpm"
                  node-version-file: package.json

            - name: Install Deps
-              run: "yarn install --frozen-lockfile"
+              run: "pnpm install --frozen-lockfile"

            - name: Run linter
-              run: "yarn run lint:knip"
+              run: "pnpm run lint:knip"

    element-web:
        name: Downstream tsc element-web
        if: github.event_name == 'merge_group'
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+            - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
              with:
                  repository: element-hq/element-web
+                  persist-credentials: false

-            - uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
+            - uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
+                  cache: "pnpm"
                  node-version: "lts/*"

            - name: Install Dependencies
@@ -159,15 +178,22 @@ jobs:
                  JS_SDK_GITHUB_BASE_REF: ${{ github.sha }}

            - name: Typecheck
-              run: "yarn run lint:types"
+              working-directory: apps/web
+              run: "pnpm run lint:types"

-    # Hook for branch protection to skip downstream typechecking outside of merge queues
-    downstream:
-        name: Downstream Typescript Syntax Check
+    # Workflow consolidation job
+    done:
+        needs:
+            - ts_lint
+            - js_lint
+            - node_example_lint
+            - workflow_lint
+            - docs
+            - analyse_dead_code
+            - element-web
+        name: Static Analysis
        runs-on: ubuntu-24.04
        if: always()
-        needs:
-            - element-web
        steps:
-            - if: needs.element-web.result != 'skipped' && needs.element-web.result != 'success'
+            - if: contains(needs.*.result , 'failure') || contains(needs.*.result, 'cancelled')
              run: exit 1
@@ -11,7 +11,7 @@ on:
 permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
    sync-labels:
-        uses: element-hq/element-meta/.github/workflows/sync-labels.yml@develop
+        uses: element-hq/element-meta/.github/workflows/sync-labels.yml@7f2f93fb9b52ece7a0998f60e64862aa203c1746
        with:
            LABELS: |
                element-hq/element-meta
@@ -12,8 +12,8 @@ env:
    ENABLE_COVERAGE: ${{ github.event_name != 'merge_group' }}
 permissions: {} # No permissions required
 jobs:
-    jest:
-        name: "Jest [${{ matrix.specs }}] (Node ${{ matrix.node == '*' && 'latest' || matrix.node }})"
+    test:
+        name: "Vitest [${{ matrix.specs }}] (Node ${{ matrix.node == '*' && 'latest' || matrix.node }})"
        runs-on: ubuntu-24.04
        timeout-minutes: 10
        strategy:
@@ -22,17 +22,20 @@ jobs:
                node: ["lts/*", 22]
        steps:
            - name: Checkout code
-              uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4
+              uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+              with:
+                  persist-credentials: false

+            - uses: pnpm/action-setup@fc06bc1257f339d1d5d8b3a19a8cae5388b55320 # v5
            - name: Setup Node
              id: setupNode
-              uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4
+              uses: actions/setup-node@48b55a011bda9f5d6aeb4c2d9c7362e8dae4041e # v6
              with:
-                  cache: "yarn"
+                  cache: "pnpm"
                  node-version: ${{ matrix.node }}

            - name: Install dependencies
-              run: "yarn install"
+              run: "pnpm install"

            - name: Get number of CPU cores
              id: cpu-cores
@@ -40,24 +43,23 @@ jobs:

            - name: Run tests
              run: |
-                  yarn test \
-                      --coverage=${{ env.ENABLE_COVERAGE }} \
-                      --ci \
-                      --max-workers ${{ steps.cpu-cores.outputs.count }} \
+                  pnpm test \
+                      --coverage=${ENABLE_COVERAGE} \
+                      --maxWorkers ${NUM_WORKERS} \
                      ./spec/${{ matrix.specs }}
              env:
-                  JEST_SONAR_UNIQUE_OUTPUT_NAME: true
-
-                  # tell jest to use coloured output
-                  FORCE_COLOR: true
+                  SHARD: ${{ matrix.specs }}
+                  NUM_WORKERS: ${{ steps.cpu-cores.outputs.count }}

            - name: Move coverage files into place
              if: env.ENABLE_COVERAGE == 'true'
-              run: mv coverage/lcov.info coverage/${{ steps.setupNode.outputs.node-version }}-${{ matrix.specs }}.lcov.info
+              run: mv coverage/lcov.info coverage/${NODE_VERSION}-${{ matrix.specs }}.lcov.info
+              env:
+                  NODE_VERSION: ${{ steps.setupNode.outputs.node-version }}

            - name: Upload Artifact
              if: env.ENABLE_COVERAGE == 'true'
-              uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
+              uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
              with:
                  name: coverage-${{ matrix.specs }}-${{ matrix.node == 'lts/*' && 'lts' || matrix.node }}
                  path: |
@@ -65,19 +67,19 @@ jobs:
                      !coverage/lcov-report

    # Dummy completion job to simplify branch protections
-    jest-complete:
-        name: Jest tests
-        needs: jest
+    complete:
+        name: Tests
+        needs: test
        if: always()
        runs-on: ubuntu-24.04
        steps:
-            - if: needs.jest.result != 'skipped' && needs.jest.result != 'success'
+            - if: needs.test.result != 'skipped' && needs.test.result != 'success'
              run: exit 1

    element-web:
        name: Downstream test element-web
        if: github.event_name == 'merge_group'
-        uses: element-hq/element-web/.github/workflows/tests.yml@develop
+        uses: element-hq/element-web/.github/workflows/tests.yml@develop # zizmor: ignore[unpinned-uses]
        permissions:
            statuses: write
        with:
@@ -87,8 +89,8 @@ jobs:
    complement-crypto:
        name: "Run Complement Crypto tests"
        if: github.event_name == 'merge_group'
-        permissions: read-all
-        uses: matrix-org/complement-crypto/.github/workflows/single_sdk_tests.yml@main
+        permissions: read-all # zizmor: ignore[excessive-permissions]
+        uses: matrix-org/complement-crypto/.github/workflows/single_sdk_tests.yml@main # zizmor: ignore[unpinned-uses]
        with:
            use_js_sdk: "."

@@ -116,7 +118,7 @@ jobs:
        steps:
            - name: Skip SonarCloud on merge queues
              if: env.ENABLE_COVERAGE == 'false'
-              uses: guibranco/github-status-action-v2@5f2b01ce1394109f70954ae6b69ef41cf7928e63
+              uses: guibranco/github-status-action-v2@9bfa8773cdbdc6c185747fd43cd7faa9d7c32f09
              with:
                  authToken: ${{ secrets.GITHUB_TOKEN }}
                  state: success
@@ -8,7 +8,7 @@ jobs:
    automate-project-columns-next:
        runs-on: ubuntu-24.04
        steps:
-            - uses: actions/add-to-project@main
+            - uses: actions/add-to-project@244f685bbc3b7adfa8466e08b698b5577571133e # v1.0.2
              with:
                  project-url: https://github.com/orgs/element-hq/projects/120
                  github-token: ${{ secrets.ELEMENT_BOT_TOKEN }}
@@ -6,6 +6,6 @@ on:
 permissions: {} # We use ELEMENT_BOT_TOKEN instead
 jobs:
    call-triage-labelled:
-        uses: element-hq/element-web/.github/workflows/triage-labelled.yml@develop
+        uses: element-hq/element-web/.github/workflows/triage-labelled.yml@6339bcda15c71d209303b18a06a9b1c021220bf9
        secrets:
            ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
@@ -12,7 +12,7 @@ jobs:
            issues: write
            pull-requests: write
        steps:
-            - uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9
+            - uses: actions/stale@b5d41d4e1d5dceea10e7104786b73624c18a190f # v10
              with:
                  operations-per-run: 250
                  days-before-issue-stale: -1
@@ -3,6 +3,7 @@

 /.npmrc
 /*.log
+pnpm-lock.yaml
 package-lock.json
 .lock-wscript
 build/Release
@@ -1,3 +1,301 @@
+Changes in [41.3.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v41.3.0) (2026-04-07)
+==================================================================================================
+## 🐛 Bug Fixes
+
+* Rotate the current room key when we see a member leave ([#5231](https://github.com/matrix-org/matrix-js-sdk/pull/5231)). Contributed by @kaylendog.
+
+
+Changes in [41.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v41.2.0) (2026-03-24)
+==================================================================================================
+## ✨ Features
+
+* Only share history if room history visibility is shared ([#5216](https://github.com/matrix-org/matrix-js-sdk/pull/5216)). Contributed by @kaylendog.
+* History sharing: resume key-bundle import on restart ([#5214](https://github.com/matrix-org/matrix-js-sdk/pull/5214)). Contributed by @richvdh.
+* Move `CryptoApi.shareRoomHistoryWithUser` to `CryptoBackend` ([#5218](https://github.com/matrix-org/matrix-js-sdk/pull/5218)). Contributed by @richvdh.
+
+
+Changes in [41.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v41.1.0) (2026-03-10)
+==================================================================================================
+## ✨ Features
+
+* Throw a specific error when the backup decryption key does not match the public backup ([#5202](https://github.com/matrix-org/matrix-js-sdk/pull/5202)). Contributed by @andybalaam.
+* Update getUrlPreview to use /\_matrix/client/v1/media/preview\_url ([#5191](https://github.com/matrix-org/matrix-js-sdk/pull/5191)). Contributed by @Half-Shot.
+
+
+Changes in [41.0.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v41.0.0) (2026-02-24)
+==================================================================================================
+## 🚨 BREAKING CHANGES
+
+* Add support for Matrix Spec v1.13 ([#5160](https://github.com/matrix-org/matrix-js-sdk/pull/5160)). Contributed by @t3chguy.
+
+## ✨ Features
+
+* Download room keys from backup prior to buliding historic room key bundles ([#5171](https://github.com/matrix-org/matrix-js-sdk/pull/5171)). Contributed by @kaylendog.
+* Add support for Matrix Spec v1.13 ([#5160](https://github.com/matrix-org/matrix-js-sdk/pull/5160)). Contributed by @t3chguy.
+* Add logging on MSC4108 DELETE request ([#5140](https://github.com/matrix-org/matrix-js-sdk/pull/5140)). Contributed by @reivilibre.
+* Add `m.invite_permission_config` account data type ([#5183](https://github.com/matrix-org/matrix-js-sdk/pull/5183)). Contributed by @richvdh.
+
+## 🐛 Bug Fixes
+
+* fix(relations): prevent stale m.replace from overriding newer edits ([#5192](https://github.com/matrix-org/matrix-js-sdk/pull/5192)). Contributed by @basnijholt.
+* Fix reactive display name disambiguation ([#5135](https://github.com/matrix-org/matrix-js-sdk/pull/5135)). Contributed by @aditya-cherukuru.
+* Fix empty string to room compatibility trick to only apply to m.call ([#5172](https://github.com/matrix-org/matrix-js-sdk/pull/5172)). Contributed by @toger5.
+
+
+Changes in [40.2.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v40.2.0) (2026-02-10)
+==================================================================================================
+## 🦖 Deprecations
+
+* [MatrixRTC] Remove sending of deprecated `notify` event (we now use `m.rtc.notification`) ([#5167](https://github.com/matrix-org/matrix-js-sdk/pull/5167)). Contributed by @toger5.
+
+## ✨ Features
+
+* Use stable /auth\_metadata endpoint where homeserver supports v1.15 ([#5174](https://github.com/matrix-org/matrix-js-sdk/pull/5174)). Contributed by @hughns.
+* Support additional\_creators in upgradeRoom (MSC4289) ([#5173](https://github.com/matrix-org/matrix-js-sdk/pull/5173)). Contributed by @andybalaam.
+* [MatrixRTC] Minimal change to transition from "" to "ROOM" as the callId/slotId ([#5166](https://github.com/matrix-org/matrix-js-sdk/pull/5166)). Contributed by @toger5.
+* [MatrixRTC] Do not send the `livekit_alias` in sticky events ([#5165](https://github.com/matrix-org/matrix-js-sdk/pull/5165)). Contributed by @toger5.
+* Improve startup performance by using `promise.all` when processing rooms from sync ([#5095](https://github.com/matrix-org/matrix-js-sdk/pull/5095)). Contributed by @MidhunSureshR.
+* Add OAuthGrantType enum for OAuth 2.0 API grant types ([#5161](https://github.com/matrix-org/matrix-js-sdk/pull/5161)). Contributed by @hughns.
+* Add support for stable OAuth2.0 aware feature from MSC3824 ([#5159](https://github.com/matrix-org/matrix-js-sdk/pull/5159)). Contributed by @hughns.
+* Give RoomWidgetClient the ability to send and receive sticky events ([#5142](https://github.com/matrix-org/matrix-js-sdk/pull/5142)). Contributed by @robintown.
+
+## 🐛 Bug Fixes
+
+* [js sdk embedded/widget] Fix race where this.syncApi.injectRoomEvents was called before the syncApi is instantiated ([#5168](https://github.com/matrix-org/matrix-js-sdk/pull/5168)). Contributed by @toger5.
+* [MatrixRTC] Fix delayId not resetting on leave ([#5156](https://github.com/matrix-org/matrix-js-sdk/pull/5156)). Contributed by @toger5.
+
+
+Changes in [40.1.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v40.1.0) (2026-01-27)
+==================================================================================================
+## 🦖 Deprecations
+
+* Deprecate unused `EventShieldReason` reason codes ([#5127](https://github.com/matrix-org/matrix-js-sdk/pull/5127)). Contributed by @richvdh.
+
+## ✨ Features
+
+* Add stable m.oauth UIA stage enum ([#5138](https://github.com/matrix-org/matrix-js-sdk/pull/5138)). Contributed by @hughns.
+* Add `MatrixEvent.getKeyForwardingUser` ([#5128](https://github.com/matrix-org/matrix-js-sdk/pull/5128)). Contributed by @richvdh.
+* Add types for (unstable) policy servers ([#5116](https://github.com/matrix-org/matrix-js-sdk/pull/5116)). Contributed by @turt2live.
+
+## 🐛 Bug Fixes
+
+* [Backport staging] Recalculate room name on loading members ([#5164](https://github.com/matrix-org/matrix-js-sdk/pull/5164)). Contributed by @RiotRobot.
+* Avoid rapidly retrying failed requests ([#5146](https://github.com/matrix-org/matrix-js-sdk/pull/5146)). Contributed by @andybalaam.
+* [matrixRTC] MatrixRTCSessions, add missing event reemission. ([#5144](https://github.com/matrix-org/matrix-js-sdk/pull/5144)). Contributed by @toger5.
+* Use normal base64 encoding for RTC backend identities ([#5129](https://github.com/matrix-org/matrix-js-sdk/pull/5129)). Contributed by @robintown.
+* export parseCallNotificationContent and isMyMembership from RTC types ([#5132](https://github.com/matrix-org/matrix-js-sdk/pull/5132)). Contributed by @Half-Shot.
+
+
+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
+
+* Deprecate non-functional `IJoinRoomOpts.syncRoom` ([#4913](https://github.com/matrix-org/matrix-js-sdk/pull/4913)). Contributed by @richvdh.
+
+## ✨ Features
+
+* Custom abort timeout logic for restarting delayed events that is compatible with the widget api ([#4927](https://github.com/matrix-org/matrix-js-sdk/pull/4927)). Contributed by @toger5.
+* Allow sending notification events when starting a call ([#4826](https://github.com/matrix-org/matrix-js-sdk/pull/4826)). Contributed by @robintown.
+
+## 🐛 Bug Fixes
+
+* Fix deep import incompatibility (#4924) ([#4925](https://github.com/matrix-org/matrix-js-sdk/pull/4925)). Contributed by @toriningen.
+* Fix more incorrect logger use ([#4904](https://github.com/matrix-org/matrix-js-sdk/pull/4904)). Contributed by @richvdh.
+
+
+Changes in [37.11.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v37.11.0) (2025-07-15)
+====================================================================================================
+## ✨ Features
+
+* Update README to make Element sponsorship explicit ([#4901](https://github.com/matrix-org/matrix-js-sdk/pull/4901)). Contributed by @neilisfragile.
+* Use client logger in more places (crypto code) ([#4900](https://github.com/matrix-org/matrix-js-sdk/pull/4900)). Contributed by @richvdh.
+* Use client logger in `MatrixRTCSessionManager` ([#4898](https://github.com/matrix-org/matrix-js-sdk/pull/4898)). Contributed by @richvdh.
+* Use client logger in more places (core code) ([#4899](https://github.com/matrix-org/matrix-js-sdk/pull/4899)). Contributed by @richvdh.
+* crypto: Add new `ClientEvent.ReceivedToDeviceMessage` with proper `OlmEncryptionInfo` support ([#4891](https://github.com/matrix-org/matrix-js-sdk/pull/4891)). Contributed by @BillCarsonFr.
+
+
 Changes in [37.10.0](https://github.com/matrix-org/matrix-js-sdk/releases/tag/v37.10.0) (2025-07-01)
 ====================================================================================================
 ## ✨ Features
@@ -117,7 +117,7 @@ checks, so please check back after a few minutes.
 Your PR should include tests.

 For new user facing features in `matrix-js-sdk`, you
-must include comprehensive unit tests written in Jest.
+must include comprehensive unit tests written in Vitest.
 The existing tests can be found under `spec/unit`

 It's good practice to write tests alongside the code as it ensures the code is testable from
@@ -11,6 +11,22 @@
 This is the [Matrix](https://matrix.org) Client-Server SDK for JavaScript and TypeScript. This SDK can be run in a
 browser or in Node.js.

+---
+
+<picture>
+  <source srcset="contrib/element-logo-light.png" media="(prefers-color-scheme: dark)">
+  <source srcset="contrib/element-logo-dark.png" media="(prefers-color-scheme: light)">
+  <img src="contrib/element-logo-fallback.png" alt="Element logo">
+</picture>
+
+<br>
+
+Development and maintenance is proudly sponsored by [Element](https://element.io). Element uses the SDK in their flagship [web](https://github.com/element-hq/element-web) and [desktop](https://github.com/element-hq/element-desktop) clients.
+
+The SDK is also the basis for multiple Matrix projects and we welcome contributions from all.
+
+---
+
 #### Minimum Matrix server version: v1.1

 The Matrix specification is constantly evolving - while this SDK aims for maximum backwards compatibility, it only
@@ -25,10 +41,10 @@ endpoints from before Matrix 1.1, for example.
 > Servers may require or use authenticated endpoints for media (images, files, avatars, etc). See the
 > [Authenticated Media](#authenticated-media) section for information on how to enable support for this.

-Using `yarn` instead of `npm` is recommended. Please see the Yarn [install guide](https://classic.yarnpkg.com/en/docs/install)
-if you do not have it already.
+Using `pnpm` instead of `npm` is recommended. Please see the pnpm [install
+guide](https://pnpm.io/installation#using-corepack) if you do not have it already.

-`yarn add matrix-js-sdk`
+`pnpm add matrix-js-sdk`

 ```javascript
 import * as sdk from "matrix-js-sdk";
@@ -294,7 +310,7 @@ This SDK uses [Typedoc](https://typedoc.org/guides/doccomments) doc comments. Yo
 host the API reference from the source files like this:

 ```
-  $ yarn gendoc
+  $ pnpm gendoc
  $ cd docs
  $ python -m http.server 8005
 ```
@@ -437,7 +453,7 @@ want to use this SDK, skip this section._
 First, you need to pull in the right build tools:

 ```
- $ yarn install
+ $ pnpm install
 ```

 ## Building
@@ -445,17 +461,17 @@ First, you need to pull in the right build tools:
 To build a browser version from scratch when developing:

 ```
- $ yarn build
+ $ pnpm build
 ```

-To run tests (Jest):
+To run tests:

 ```
- $ yarn test
+ $ pnpm test
 ```

 To run linting:

 ```
- $ yarn lint
+ $ pnpm lint
 ```
@@ -7,21 +7,13 @@ module.exports = {
                targets: {
                    esmodules: true,
                },
-                // We want to output ES modules for the final build (mostly to ensure that
-                // async imports work correctly). However, jest doesn't support ES modules very
-                // well yet (see https://github.com/jestjs/jest/issues/9430), so we use commonjs
-                // when testing.
-                modules: process.env.NODE_ENV === "test" ? "commonjs" : false,
+                modules: false,
            },
        ],
        [
            "@babel/preset-typescript",
            {
-                // When using the transpiled javascript in `lib`, Node.js requires `.js` extensions on any `import`
-                // specifiers. However, Jest uses the TS source (via babel) and fails to resolve the `.js` names.
-                // To resolve this,we use the `.ts` names in the source, and rewrite the `import` specifiers to use
-                // `.js` during transpilation, *except* when we are targetting Jest.
-                rewriteImportExtensions: process.env.NODE_ENV !== "test",
+                rewriteImportExtensions: true,
            },
        ],
    ],
@@ -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.
@@ -119,7 +119,6 @@ Unless otherwise specified, the following applies to all code:
    2. "Conflicted" typically refers to a getter which wants the same name as the underlying variable.
 20. Prefer readonly members over getters backed by a variable, unless an internal setter is required.
 21. Prefer Interfaces for object definitions, and types for parameter-value-only declarations.
-
    1. Note that an explicit type is optional if not expected to be used outside of the function call,
       unlike in this example:

@@ -151,9 +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
@@ -163,7 +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
        ) {
            // ...
        }
@@ -216,7 +213,7 @@ Unless otherwise specified, the following applies to all code:
 ## Tests

 1. Tests must be written in TypeScript.
-2. Jest mocks are declared below imports, but above everything else.
+2. Mocks are declared below imports, but above everything else.
 3. Use the following convention template:

    ```typescript
@@ -272,7 +269,6 @@ Unless otherwise specified, the following applies to all code:
    interfaces have a habit of becoming more complex over time.

 3. Inside a function, there is no need to comment every line, but consider:
-
    - before a particular multiline section of code within the function, give an overview of what it does,
      to make it easier for a reader to follow the flow through the function as a whole.
    - if it is anything less than obvious, explain _why_ we are doing a particular operation, with particular emphasis
@@ -21,4 +21,4 @@ export PATH="$rootdir/node_modules/.bin:$PATH"

 # now run our checks
 cd "$tmpdir"
-yarn lint
+pnpm lint
@@ -1,47 +0,0 @@
-/* Copyright 2023 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import type { Config } from "jest";
-import { env } from "process";
-
-const config: Config = {
-    testEnvironment: "node",
-    testMatch: ["<rootDir>/spec/**/*.spec.{js,ts}"],
-    setupFilesAfterEnv: ["<rootDir>/spec/setupTests.ts"],
-    collectCoverageFrom: ["<rootDir>/src/**/*.{js,ts}"],
-    coverageReporters: ["text-summary", "lcov"],
-    testResultsProcessor: "@casualbot/jest-sonar-reporter",
-
-    // 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*.
-    reporters: [["default", { summaryThreshold: 0 }]],
-};
-
-// if we're running under GHA, enable the GHA reporter
-if (env["GITHUB_ACTIONS"] !== undefined) {
-    const reporters: Config["reporters"] = [
-        ["github-actions", { silent: false }],
-        // as above: always show a summary if there were any failing tests.
-        ["summary", { summaryThreshold: 0 }],
-    ];
-
-    // if we're running against the develop branch, also enable the slow test reporter
-    if (env["GITHUB_REF"] == "refs/heads/develop") {
-        reporters.push("<rootDir>/spec/slowReporter.cjs");
-    }
-    config.reporters = reporters;
-}
-
-export default config;
@@ -1,5 +1,8 @@
 import { KnipConfig } from "knip";

+// Specify this as knip loads config files which may conditionally add reporters, e.g. `vitest-sonar-reporter'
+process.env.GITHUB_ACTIONS = "1";
+
 export default {
    entry: [
        "src/index.ts",
@@ -12,10 +15,6 @@ 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",
@@ -32,12 +31,6 @@ export default {
        "husky",
        // Used in script which only runs in environment with `@octokit/rest` installed
        "@octokit/rest",
-        // Used by jest
-        "jest-environment-jsdom",
-        "babel-jest",
-        "ts-node",
-        // Used by `@babel/plugin-transform-runtime`
-        "@babel/runtime",
    ],
    ignoreBinaries: [
        // Used when available by reusable workflow `.github/workflows/release-make.yml`
@@ -1,27 +1,26 @@
 {
    "name": "matrix-js-sdk",
-    "version": "37.10.0",
+    "version": "41.3.0",
    "description": "Matrix Client-Server SDK for Javascript",
    "engines": {
        "node": ">=22.0.0"
    },
    "scripts": {
-        "prepare": "yarn build",
-        "start": "echo THIS IS FOR LEGACY PURPOSES ONLY. && babel src -w -s -d lib --verbose --extensions \".ts,.js\"",
-        "clean": "rimraf lib",
-        "build": "yarn clean && yarn build:compile && yarn build:types",
+        "prepare": "pnpm build",
+        "start": "echo THIS IS FOR LEGACY PURPOSES ONLY. && babel --delete-dir-on-start src -w -s -d lib --verbose --extensions \".ts,.js\"",
+        "build": "pnpm build:compile && pnpm build:types",
        "build:types": "tsc -p tsconfig-build.json --emitDeclarationOnly",
-        "build:compile": "babel -d lib --verbose --extensions \".ts,.js\" src",
+        "build:compile": "babel --delete-dir-on-start -d lib --verbose --extensions \".ts,.js\" src",
        "gendoc": "typedoc",
-        "lint": "yarn lint:types && yarn lint:js && yarn lint:workflows",
+        "lint": "pnpm lint:types && pnpm lint:js && pnpm lint:workflows",
        "lint:js": "eslint --max-warnings 0 src spec && prettier --check .",
        "lint:js-fix": "prettier --log-level=warn --write . && eslint --fix src spec",
        "lint:types": "tsc --noEmit",
        "lint:workflows": "find .github/workflows -type f \\( -iname '*.yaml' -o -iname '*.yml' \\) | xargs -I {} sh -c 'echo \"Linting {}\"; action-validator \"{}\"'",
        "lint:knip": "knip",
-        "test": "jest",
-        "test:watch": "jest --watch",
-        "coverage": "yarn test --coverage"
+        "test": "vitest run",
+        "test:watch": "vitest watch",
+        "coverage": "pnpm test --coverage"
    },
    "repository": {
        "type": "git",
@@ -49,19 +48,18 @@
    ],
    "dependencies": {
        "@babel/runtime": "^7.12.5",
-        "@matrix-org/matrix-sdk-crypto-wasm": "^15.0.0",
+        "@matrix-org/matrix-sdk-crypto-wasm": "^18.1.0",
        "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": "^1.16.1",
        "oidc-client-ts": "^3.0.1",
-        "p-retry": "4",
-        "sdp-transform": "^2.14.1",
-        "unhomoglyph": "^1.0.6",
-        "uuid": "11"
+        "p-retry": "8",
+        "sdp-transform": "^3.0.0",
+        "unhomoglyph": "^1.0.6"
    },
    "devDependencies": {
        "@action-validator/cli": "^0.6.0",
@@ -78,18 +76,19 @@
        "@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",
+        "@fetch-mock/vitest": "^0.2.18",
        "@matrix-org/olm": "3.2.15",
        "@peculiar/webcrypto": "^1.4.5",
-        "@stylistic/eslint-plugin": "^4.0.0",
+        "@stylistic/eslint-plugin": "^5.0.0",
        "@types/content-type": "^1.1.5",
        "@types/debug": "^4.1.7",
-        "@types/jest": "^29.0.0",
-        "@types/node": "18",
+        "@types/node": "22",
        "@types/sdp-transform": "^2.4.5",
        "@typescript-eslint/eslint-plugin": "^8.0.0",
        "@typescript-eslint/parser": "^8.0.0",
-        "babel-jest": "^29.0.0",
+        "@vitest/coverage-v8": "^4.0.17",
+        "@vitest/eslint-plugin": "^1.6.6",
+        "@vitest/ui": "^4.0.17",
        "babel-plugin-search-and-replace": "^1.1.1",
        "debug": "^4.3.4",
        "eslint": "8.57.1",
@@ -97,36 +96,43 @@
        "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-jsdoc": "^62.0.0",
+        "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",
+        "fetch-mock": "^12.6.0",
+        "happy-dom": "^20.1.0",
        "husky": "^9.0.0",
-        "jest": "^29.0.0",
-        "jest-environment-jsdom": "^29.0.0",
-        "jest-localstorage-mock": "^2.4.6",
-        "jest-mock": "^29.0.0",
-        "knip": "^5.0.0",
+        "knip": "^6.0.0",
        "lint-staged": "^16.0.0",
        "matrix-mock-request": "^2.5.0",
-        "node-fetch": "^2.7.0",
-        "prettier": "3.5.3",
-        "rimraf": "^6.0.0",
-        "ts-node": "^10.9.2",
+        "prettier": "3.8.3",
        "typedoc": "^0.28.1",
        "typedoc-plugin-coverage": "^4.0.0",
        "typedoc-plugin-mdn-links": "^5.0.0",
        "typedoc-plugin-missing-exports": "^4.0.0",
-        "typescript": "^5.4.2"
+        "typescript": "^6.0.0",
+        "vitest": "^4.0.17",
+        "vitest-sonar-reporter": "^3.0.0"
    },
-    "@casualbot/jest-sonar-reporter": {
-        "outputDirectory": "coverage",
-        "outputName": "jest-sonar-report.xml",
-        "relativePaths": true
-    }
+    "pnpm": {
+        "peerDependencyRules": {
+            "allowedVersions": {
+                "eslint": "8"
+            }
+        },
+        "allowedDeprecatedVersions": {
+            "eslint": "8"
+        },
+        "overrides": {
+            "expect": "30.3.0",
+            "flatted@<=3.4.1": "^3.4.2",
+            "picomatch@>=4.0.0 <4.0.4": "^4.0.4",
+            "yaml@>=2.0.0 <2.8.3": "^2.8.3",
+            "vite": "8.0.8"
+        }
+    },
+    "packageManager": "pnpm@10.33.0+sha512.10568bb4a6afb58c9eb3630da90cc9516417abebd3fabbe6739f0ae795728da1491e9db5a544c76ad8eb7570f5c4bb3d6c637b2cb41bfdcdb47fa823c8649319"
 }
@@ -0,0 +1 @@
+nodeLinker: hoisted
@@ -11,6 +11,6 @@ sonar.exclusions=docs,examples,git-hooks
 sonar.typescript.tsconfigPath=./tsconfig.json
 sonar.javascript.lcov.reportPaths=coverage/lcov.info
 sonar.coverage.exclusions=spec/**/*
-sonar.testExecutionReportPaths=coverage/jest-sonar-report.xml
+sonar.testExecutionReportPaths=coverage/sonar-report.xml

 sonar.lang.patterns.ts=**/*.ts,**/*.tsx
@@ -17,10 +17,7 @@ limitations under the License.
 */

 // `expect` is allowed in helper functions which are called within `test`/`it` blocks
-/* eslint-disable jest/no-standalone-expect */
-
-// load olm before the sdk if possible
-import "./olm-loader";
+/* eslint-disable @vitest/no-standalone-expect */

 import MockHttpBackend from "matrix-mock-request";

@@ -42,7 +39,7 @@ import { type ISyncResponder } from "./test-utils/SyncResponder";
 * Wrapper for a MockStorageApi, MockHttpBackend and MatrixClient
 *
 * @deprecated Avoid using this; it is tied too tightly to matrix-mock-request and is generally inconvenient to use.
- *    Instead, construct a MatrixClient manually, use fetch-mock-jest to intercept the HTTP requests, and
+ *    Instead, construct a MatrixClient manually, use fetch-mock to intercept the HTTP requests, and
 *    use things like {@link E2EKeyReceiver} and {@link SyncResponder} to manage the requests.
 */
 export class TestClient implements IE2EKeyReceiver, ISyncResponder {
@@ -14,12 +14,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
+import debug from "debug";

 import { syncPromise } from "../../test-utils/test-utils";
-import { type AuthDict, createClient, type MatrixClient } from "../../../src";
+import { type AuthDict, createClient, DebugLogger, type MatrixClient } from "../../../src";
 import { mockInitialApiRequests, mockSetupCrossSigningRequests } from "../../test-utils/mockEndpoints";
 import encryptAESSecretStorageItem from "../../../src/utils/encryptAESSecretStorageItem.ts";
 import { type CryptoCallbacks, CrossSigningKey } from "../../../src/crypto-api";
@@ -73,7 +74,7 @@ describe("cross-signing", () => {
    function createCryptoCallbacks(): CryptoCallbacks {
        return {
            getSecretStorageKey: (keys, name) => {
-                return Promise.resolve<[string, Uint8Array]>(["key_id", encryptionKey]);
+                return Promise.resolve<[string, Uint8Array<ArrayBuffer>]>(["key_id", encryptionKey]);
            },
        };
    }
@@ -82,7 +83,6 @@ describe("cross-signing", () => {
        async () => {
            // anything that we don't have a specific matcher for silently returns a 404
            fetchMock.catch(404);
-            fetchMock.config.warnOnFallback = false;

            const homeserverUrl = "https://alice-server.com";
            aliceClient = createClient({
@@ -91,6 +91,7 @@ describe("cross-signing", () => {
                accessToken: "akjgkrgjs",
                deviceId: TEST_DEVICE_ID,
                cryptoCallbacks: createCryptoCallbacks(),
+                logger: new DebugLogger(debug(`matrix-js-sdk:cross-signing`)),
            });

            syncResponder = new SyncResponder(homeserverUrl);
@@ -111,8 +112,7 @@ describe("cross-signing", () => {
    );

    afterEach(async () => {
-        await aliceClient.stopClient();
-        fetchMock.mockReset();
+        aliceClient.stopClient();
    });

    /**
@@ -135,28 +135,26 @@ describe("cross-signing", () => {
            const authDict = { type: "test" };
            await bootstrapCrossSigning(authDict);

-            // check the cross-signing keys upload
-            expect(fetchMock.called("upload-keys")).toBeTruthy();
-            const [, keysOpts] = fetchMock.lastCall("upload-keys")!;
+            // check that the cross-signing keys have been uploaded
+            expect(fetchMock.callHistory.called("upload-cross-signing-keys")).toBeTruthy();
+            const keysOpts = fetchMock.callHistory.lastCall("upload-cross-signing-keys")!.options;
            const keysBody = JSON.parse(keysOpts!.body as string);
            expect(keysBody.auth).toEqual(authDict); // check uia dict was passed
            // there should be a key of each type
            // master key is signed by the device
-            expect(keysBody).toHaveProperty(`master_key.signatures.[${TEST_USER_ID}].[ed25519:${TEST_DEVICE_ID}]`);
+            expect(keysBody).toHaveProperty(["master_key", "signatures", TEST_USER_ID, `ed25519:${TEST_DEVICE_ID}`]);
            const masterKeyId = Object.keys(keysBody.master_key.keys)[0];
            // ssk and usk are signed by the master key
-            expect(keysBody).toHaveProperty(`self_signing_key.signatures.[${TEST_USER_ID}].[${masterKeyId}]`);
-            expect(keysBody).toHaveProperty(`user_signing_key.signatures.[${TEST_USER_ID}].[${masterKeyId}]`);
+            expect(keysBody).toHaveProperty(["self_signing_key", "signatures", TEST_USER_ID, masterKeyId]);
+            expect(keysBody).toHaveProperty(["user_signing_key", "signatures", TEST_USER_ID, masterKeyId]);
            const sskId = Object.keys(keysBody.self_signing_key.keys)[0];

            // check the publish call
-            expect(fetchMock.called("upload-sigs")).toBeTruthy();
-            const [, sigsOpts] = fetchMock.lastCall("upload-sigs")!;
+            expect(fetchMock.callHistory.called("upload-sigs")).toBeTruthy();
+            const sigsOpts = fetchMock.callHistory.lastCall("upload-sigs")!.options;
            const body = JSON.parse(sigsOpts!.body as string);
            // there should be a signature for our device, by our self-signing key.
-            expect(body).toHaveProperty(
-                `[${TEST_USER_ID}].[${TEST_DEVICE_ID}].signatures.[${TEST_USER_ID}].[${sskId}]`,
-            );
+            expect(body).toHaveProperty([TEST_USER_ID, TEST_DEVICE_ID, "signatures", TEST_USER_ID, sskId]);
        });

        it("get cross signing keys from secret storage and import them", async () => {
@@ -223,9 +221,6 @@ describe("cross-signing", () => {
            await aliceClient.startClient();
            await syncPromise(aliceClient);

-            // we expect a request to upload signatures for our device ...
-            fetchMock.post({ url: "path:/_matrix/client/v3/keys/signatures/upload", name: "upload-sigs" }, {});
-
            // we expect the UserTrustStatusChanged event to be fired after the cross signing keys import
            const userTrustStatusChangedPromise = new Promise<string>((resolve) =>
                aliceClient.on(CryptoEvent.UserTrustStatusChanged, resolve),
@@ -238,13 +233,17 @@ describe("cross-signing", () => {
            expect(await userTrustStatusChangedPromise).toBe(aliceClient.getUserId());

            // Expect the signature to be uploaded
-            expect(fetchMock.called("upload-sigs")).toBeTruthy();
-            const [, sigsOpts] = fetchMock.lastCall("upload-sigs")!;
+            expect(fetchMock.callHistory.called("upload-sigs")).toBeTruthy();
+            const sigsOpts = fetchMock.callHistory.lastCall("upload-sigs")!.options;
            const body = JSON.parse(sigsOpts!.body as string);
            // the device should have a signature with the public self cross signing keys.
-            expect(body).toHaveProperty(
-                `[${TEST_USER_ID}].[${TEST_DEVICE_ID}].signatures.[${TEST_USER_ID}].[ed25519:${SELF_CROSS_SIGNING_PUBLIC_KEY_BASE64}]`,
-            );
+            expect(body).toHaveProperty([
+                TEST_USER_ID,
+                TEST_DEVICE_ID,
+                "signatures",
+                TEST_USER_ID,
+                `ed25519:${SELF_CROSS_SIGNING_PUBLIC_KEY_BASE64}`,
+            ]);
        });

        it("can bootstrapCrossSigning twice", async () => {
@@ -256,8 +255,7 @@ describe("cross-signing", () => {
            // a second call should do nothing except GET requests
            fetchMock.mockClear();
            await bootstrapCrossSigning(authDict);
-            const calls = fetchMock.calls((url, opts) => opts.method != "GET");
-            expect(calls.length).toEqual(0);
+            expect(fetchMock).toHaveFetchedTimes(0, "unmatched");
        });

        it("will upload existing cross-signing keys to an established secret storage", async () => {
@@ -268,7 +266,6 @@ describe("cross-signing", () => {
            // To arrange that, we call `bootstrapCrossSigning` on our main device, and then (pretend to) set up 4S from
            // a *different* device. Then, when we call `bootstrapCrossSigning` again, it should do the honours.

-            mockSetupCrossSigningRequests();
            const accountDataAccumulator = new AccountDataAccumulator(syncResponder);
            accountDataAccumulator.interceptGetAccountData();

@@ -283,7 +280,7 @@ describe("cross-signing", () => {
            });

            // Prepare for the cross-signing keys
-            const p = accountDataAccumulator.interceptSetAccountData(":type(m.cross_signing..*)");
+            const p = accountDataAccumulator.waitForAccountData("m.cross_signing.master");

            await bootstrapCrossSigning(authDict);
            await p;
@@ -404,7 +401,7 @@ describe("cross-signing", () => {
            const isCrossSigningReady = await aliceClient.getCrypto()!.isCrossSigningReady();

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

    describe("getCrossSigningKeyId", () => {
@@ -416,19 +413,13 @@ describe("cross-signing", () => {
         */
        function awaitCrossSigningKeysUpload() {
            return new Promise<any>((resolve) => {
-                fetchMock.post(
-                    {
-                        url: new RegExp("/_matrix/client/v3/keys/device_signing/upload"),
-                        name: "upload-keys",
-                    },
-                    (url, options) => {
-                        const content = JSON.parse(options.body as string);
+                fetchMock.modifyRoute("upload-cross-signing-keys", {
+                    response: (callLog) => {
+                        const content = JSON.parse(callLog.options.body as string);
                        resolve(content);
                        return {};
                    },
-                    // Override the routes define in `mockSetupCrossSigningRequests`
-                    { overwriteRoutes: true },
-                );
+                });
            });
        }

@@ -459,9 +450,6 @@ describe("cross-signing", () => {

    describe("crossSignDevice", () => {
        beforeEach(async () => {
-            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
-
            // make sure that there is another device which we can sign
            e2eKeyResponder.addDeviceKeys(SIGNED_TEST_DEVICE_DATA);

@@ -475,10 +463,6 @@ describe("cross-signing", () => {
            expect(devices.get(aliceClient.getSafeUserId())!.has(testData.TEST_DEVICE_ID)).toBeTruthy();
        });

-        afterEach(async () => {
-            jest.useRealTimers();
-        });
-
        it("fails for an unknown device", async () => {
            await expect(aliceClient.getCrypto()!.crossSignDevice("unknown")).rejects.toThrow("Unknown device");
        });
@@ -491,9 +475,9 @@ describe("cross-signing", () => {
            await aliceClient.getCrypto()!.crossSignDevice(testData.TEST_DEVICE_ID);

            // check that a sig for the device was uploaded
-            const calls = fetchMock.calls("upload-sigs");
+            const calls = fetchMock.callHistory.calls("upload-sigs");
            expect(calls.length).toEqual(1);
-            const body = JSON.parse(calls[0][1]!.body as string);
+            const body = JSON.parse(calls[0].options!.body as string);
            const deviceSig = body[aliceClient.getSafeUserId()][testData.TEST_DEVICE_ID];
            expect(deviceSig).toHaveProperty("signatures");
        });
@@ -16,12 +16,12 @@ limitations under the License.
 */

 import anotherjson from "another-json";
-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
+import Olm from "@matrix-org/olm";
+import { type RouteResponse } from "fetch-mock";

-import type FetchMock from "fetch-mock";
-import type Olm from "@matrix-org/olm";
 import * as testUtils from "../../test-utils/test-utils";
 import {
    emitPromise,
@@ -86,9 +86,13 @@ import {
    encryptGroupSessionKey,
    encryptMegolmEvent,
    encryptMegolmEventRawPlainText,
+    encryptOlmEvent,
    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";
@@ -101,120 +105,10 @@ afterEach(() => {
    // eslint-disable-next-line no-global-assign
    indexedDB = new IDBFactory();

-    jest.useRealTimers();
+    vi.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 Olm = globalThis.Olm;
-    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", () => {
-    if (!globalThis.Olm) {
-        // currently we use libolm to implement the crypto in the tests, so need it to be present.
-        logger.warn("not running megolm tests: Olm not present");
-        return;
-    }
-
-    const Olm = globalThis.Olm;
-
    let testOlmAccount = {} as unknown as Olm.Account;
    let testSenderKey = "";

@@ -261,13 +155,8 @@ describe("crypto", () => {
            return response;
        }
        const rootRegexp = escapeRegExp(new URL("/_matrix/client/", aliceClient.getHomeserverUrl()).toString());
-        fetchMock.postOnce(
-            new RegExp(rootRegexp + "(r0|v3)/keys/query"),
-            (url: string, opts: RequestInit) => onQueryRequest(JSON.parse(opts.body as string)),
-            {
-                // append to the list of intercepts on this path
-                overwriteRoutes: false,
-            },
+        fetchMock.postOnce(new RegExp(rootRegexp + "(r0|v3)/keys/query"), (callLog) =>
+            onQueryRequest(JSON.parse(callLog.options.body as string)),
        );
    }

@@ -277,7 +166,7 @@ describe("crypto", () => {
     * @param response - the response to return from the request. Normally an {@link IClaimOTKsResult}
     *   (or a function that returns one).
     */
-    function expectAliceKeyClaim(response: FetchMock.MockResponse | FetchMock.MockResponseFunction) {
+    function expectAliceKeyClaim(response: RouteResponse) {
        const rootRegexp = escapeRegExp(new URL("/_matrix/client/", aliceClient.getHomeserverUrl()).toString());
        fetchMock.postOnce(new RegExp(rootRegexp + "(r0|v3)/keys/claim"), response);
    }
@@ -330,15 +219,20 @@ describe("crypto", () => {
     */
    function createCryptoCallbacks(): CryptoCallbacks {
        // Store the cached secret storage key and return it when `getSecretStorageKey` is called
-        let cachedKey: { keyId: string; key: Uint8Array };
-        const cacheSecretStorageKey = (keyId: string, keyInfo: SecretStorageKeyDescription, key: Uint8Array) => {
+        let cachedKey: { keyId: string; key: Uint8Array<ArrayBuffer> };
+        const cacheSecretStorageKey = (
+            keyId: string,
+            keyInfo: SecretStorageKeyDescription,
+            key: Uint8Array<ArrayBuffer>,
+        ) => {
            cachedKey = {
                keyId,
                key,
            };
        };

-        const getSecretStorageKey = () => Promise.resolve<[string, Uint8Array]>([cachedKey.keyId, cachedKey.key]);
+        const getSecretStorageKey = () =>
+            Promise.resolve<[string, Uint8Array<ArrayBuffer>]>([cachedKey.keyId, cachedKey.key]);

        return {
            cacheSecretStorageKey,
@@ -350,7 +244,6 @@ describe("crypto", () => {
        async () => {
            // anything that we don't have a specific matcher for silently returns a 404
            fetchMock.catch(404);
-            fetchMock.config.warnOnFallback = false;

            const homeserverUrl = "https://alice-server.com";
            aliceClient = createClient({
@@ -372,18 +265,20 @@ describe("crypto", () => {
            testOlmAccount = await createOlmAccount();
            const testE2eKeys = JSON.parse(testOlmAccount.identity_keys());
            testSenderKey = testE2eKeys.curve25519;
+
+            vi.useRealTimers();
        },
        /* it can take a while to initialise the crypto library on the first pass, so bump up the timeout. */
        10000,
    );

    afterEach(async () => {
-        await aliceClient.stopClient();
+        aliceClient.stopClient();

        // Allow in-flight things to complete before we tear down the test
-        await jest.runAllTimersAsync();
-
-        fetchMock.mockReset();
+        if (vi.isFakeTimers()) {
+            await vi.runAllTimersAsync();
+        }
    });

    it("MatrixClient.getCrypto returns a CryptoApi", () => {
@@ -450,7 +345,7 @@ describe("crypto", () => {

    describe("Unable to decrypt error codes", function () {
        beforeEach(() => {
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+            vi.useFakeTimers();
        });

        it("Decryption fails with UISI error", async () => {
@@ -826,7 +721,7 @@ describe("crypto", () => {
            syncResponder.sendOrQueueSyncResponse(syncResponse);
            await syncPromise(aliceClient);

-            await awaitDecryptionError;
+            await expect(awaitDecryptionError).resolves.toBeUndefined();
        });
    });

@@ -977,6 +872,7 @@ describe("crypto", () => {
        await expectSendRoomKey("@bob:xyz", testOlmAccount);
    });

+    // eslint-disable-next-line @vitest/expect-expect
    it("Alice sends a megolm message", async () => {
        const homeserverUrl = aliceClient.getHomeserverUrl();
        const keyResponder = new E2EKeyResponder(homeserverUrl);
@@ -1000,10 +896,11 @@ 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),
        ]);
    });

+    // eslint-disable-next-line @vitest/expect-expect
    it("We should start a new megolm session after forceDiscardSession", async () => {
        const homeserverUrl = aliceClient.getHomeserverUrl();
        const keyResponder = new E2EKeyResponder(homeserverUrl);
@@ -1027,7 +924,7 @@ 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.
@@ -1035,7 +932,7 @@ 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]);
    });

@@ -1046,7 +943,7 @@ describe("crypto", () => {
         */
        async function sendEncryptedMessage(): Promise<IContent> {
            const [encryptedMessage] = await Promise.all([
-                expectEncryptedSendMessage(),
+                expectEncryptedSendMessageEvent(),
                aliceClient.sendTextMessage(ROOM_ID, "test"),
            ]);
            return encryptedMessage;
@@ -1104,9 +1001,7 @@ describe("crypto", () => {
            await startClientAndAwaitFirstSync();
            const p2pSession = await establishOlmSession(aliceClient, keyReceiver, syncResponder, testOlmAccount);

-            // We need to fake the timers to advance the time, but the wasm bindings of matrix-sdk-crypto rely on a
-            // working `queueMicrotask`
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+            vi.useFakeTimers();

            const syncResponse = getSyncResponse(["@bob:xyz"]);

@@ -1138,7 +1033,7 @@ describe("crypto", () => {
            expect(sessionId).toBeDefined();

            // Advance the time by 1h
-            jest.advanceTimersByTime(oneHourInMs);
+            vi.advanceTimersByTime(oneHourInMs);

            // Send a second message to bob and get the encrypted message
            const [secondEncryptedMessage] = await Promise.all([
@@ -1168,7 +1063,7 @@ 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
@@ -1196,7 +1091,7 @@ 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
@@ -1259,7 +1154,7 @@ describe("crypto", () => {
        // 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.getRoomId()).toEqual(ROOM_ID);
-        expect(decryptedEvent.getContent()).toEqual({});
+        expect(decryptedEvent.getContent<IContent>()).toEqual({});
        expect(decryptedEvent.getClearContent()).toBeUndefined();
    });

@@ -1283,20 +1178,12 @@ describe("crypto", () => {
            const inboundGroupSessionPromise = expectSendRoomKey("@bob:xyz", testOlmAccount);

            // ... and finally, send the room key. We block the response until `sendRoomMessageDefer` completes.
-            const sendRoomMessageResolvers = Promise.withResolvers<FetchMock.MockResponse>();
+            const sendRoomMessageResolvers = Promise.withResolvers<RouteResponse>();
            const reqProm = new Promise<IContent>((resolve) => {
-                fetchMock.putOnce(
-                    new RegExp("/send/m.room.encrypted/"),
-                    async (url: string, opts: RequestInit): Promise<FetchMock.MockResponse> => {
-                        resolve(JSON.parse(opts.body as string));
-                        return await sendRoomMessageResolvers.promise;
-                    },
-                    {
-                        // append to the list of intercepts on this path (since we have some tests that call
-                        // this function multiple times)
-                        overwriteRoutes: false,
-                    },
-                );
+                fetchMock.putOnce(new RegExp("/send/m.room.encrypted/"), async (callLog): Promise<RouteResponse> => {
+                    resolve(JSON.parse(callLog.options.body as string));
+                    return await sendRoomMessageResolvers.promise;
+                });
            });

            // Now we start to send the message
@@ -1379,6 +1266,7 @@ describe("crypto", () => {
            });
        }

+        // eslint-disable-next-line @vitest/expect-expect
        it("Sending an event initiates a member list sync", async () => {
            const homeserverUrl = aliceClient.getHomeserverUrl();
            const keyResponder = new E2EKeyResponder(homeserverUrl);
@@ -1394,7 +1282,7 @@ 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");
@@ -1402,6 +1290,7 @@ describe("crypto", () => {
            await Promise.all([sendPromise, megolmMessagePromise, memberListPromise]);
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("loading the membership list inhibits a later load", async () => {
            const homeserverUrl = aliceClient.getHomeserverUrl();
            const keyResponder = new E2EKeyResponder(homeserverUrl);
@@ -1417,7 +1306,7 @@ 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");
@@ -1500,8 +1389,10 @@ 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");
                });
            },
        );
@@ -1509,33 +1400,26 @@ describe("crypto", () => {

    describe("key upload request", () => {
        beforeEach(() => {
-            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+            vi.useFakeTimers();
        });

        function awaitKeyUploadRequest(): Promise<{ keysCount: number; fallbackKeysCount: number }> {
            return new Promise((resolve) => {
-                const listener = (url: string, options: RequestInit) => {
-                    const content = JSON.parse(options.body as string);
-                    const keysCount = Object.keys(content?.one_time_keys || {}).length;
-                    const fallbackKeysCount = Object.keys(content?.fallback_keys || {}).length;
-                    if (keysCount) resolve({ keysCount, fallbackKeysCount });
-                    return {
-                        one_time_key_counts: {
-                            // The matrix client does `/upload` requests until 50 keys are uploaded
-                            // We return here 60 to avoid the `/upload` request loop
-                            signed_curve25519: keysCount ? 60 : keysCount,
-                        },
-                    };
-                };
-
-                for (const path of ["/_matrix/client/v3/keys/upload", "/_matrix/client/v3/keys/upload"]) {
-                    fetchMock.post(new URL(path, aliceClient.getHomeserverUrl()).toString(), listener, {
-                        // These routes are already defined in the E2EKeyReceiver
-                        // We want to overwrite the behaviour of the E2EKeyReceiver
-                        overwriteRoutes: true,
-                    });
-                }
+                fetchMock.modifyRoute("keys-upload", {
+                    response: (callLog) => {
+                        const content = JSON.parse(callLog.options.body as string);
+                        const keysCount = Object.keys(content?.one_time_keys || {}).length;
+                        const fallbackKeysCount = Object.keys(content?.fallback_keys || {}).length;
+                        if (keysCount) resolve({ keysCount, fallbackKeysCount });
+                        return {
+                            one_time_key_counts: {
+                                // The matrix client does `/upload` requests until 50 keys are uploaded
+                                // We return here 60 to avoid the `/upload` request loop
+                                signed_curve25519: keysCount ? 60 : keysCount,
+                            },
+                        };
+                    },
+                });
            });
        }

@@ -1548,7 +1432,7 @@ describe("crypto", () => {

            await syncPromise(aliceClient);

-            // Verify that `/upload` is called on Alice's homesever
+            // Verify that `/upload` is called on Alice's homeserver
            const { keysCount, fallbackKeysCount } = await uploadPromise;
            expect(keysCount).toBeGreaterThan(0);
            expect(fallbackKeysCount).toBe(0);
@@ -1562,7 +1446,7 @@ describe("crypto", () => {

            // Advance local date to 2 minutes
            // The old crypto only runs the upload every 60 seconds
-            jest.setSystemTime(Date.now() + 2 * 60 * 1000);
+            vi.setSystemTime(Date.now() + 2 * 60 * 1000);

            await syncPromise(aliceClient);

@@ -1653,18 +1537,16 @@ describe("crypto", () => {

        function awaitKeyQueryRequest(): Promise<Record<string, []>> {
            return new Promise((resolve) => {
-                const listener = (url: string, options: RequestInit) => {
-                    const content = JSON.parse(options.body as string);
-                    // Resolve with request payload
-                    resolve(content.device_keys);
-
-                    // Return response of `/keys/query`
-                    return queryResponseBody;
-                };
-
                fetchMock.post(
                    new URL("/_matrix/client/v3/keys/query", aliceClient.getHomeserverUrl()).toString(),
-                    listener,
+                    (callLog) => {
+                        const content = JSON.parse(callLog.options.body as string);
+                        // Resolve with request payload
+                        resolve(content.device_keys);
+
+                        // Return response of `/keys/query`
+                        return queryResponseBody;
+                    },
                );
            });
        }
@@ -1703,8 +1585,7 @@ describe("crypto", () => {
        });

        it("Get devices from tracked users", async () => {
-            // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+            vi.useFakeTimers();

            expectAliceKeyQuery({ device_keys: { "@alice:localhost": {} }, failures: {} });
            await startClientAndAwaitFirstSync();
@@ -1716,12 +1597,12 @@ describe("crypto", () => {

            // Advance local date to 2 minutes
            // The old crypto only runs the upload every 60 seconds
-            jest.setSystemTime(Date.now() + 2 * 60 * 1000);
+            vi.setSystemTime(Date.now() + 2 * 60 * 1000);

            await syncPromise(aliceClient);

            // Old crypto: for alice: run over the `sleep(5)` in `doQueuedQueries` of `DeviceList`
-            jest.runAllTimers();
+            vi.runAllTimers();
            // Old crypto: for alice: run the `processQueryResponseForUser` in `doQueuedQueries` of `DeviceList`
            await flushPromises();

@@ -1729,7 +1610,7 @@ describe("crypto", () => {
            await queryPromise;

            // Old crypto: for `user`: run over the `sleep(5)` in `doQueuedQueries` of `DeviceList`
-            jest.runAllTimers();
+            vi.runAllTimers();
            // Old crypto: for `user`: run the `processQueryResponseForUser` in `doQueuedQueries` of `DeviceList`
            // It will add `@testing_florian1:matrix.org` devices to the DeviceList
            await flushPromises();
@@ -1753,7 +1634,7 @@ describe("crypto", () => {
         * Create a fake secret storage key
         * Async because `bootstrapSecretStorage` expect an async method
         */
-        const createSecretStorageKey = jest.fn().mockResolvedValue({
+        const createSecretStorageKey = vi.fn().mockResolvedValue({
            keyInfo: {}, // Returning undefined here used to cause a crash
            privateKey: Uint8Array.of(32, 33),
        });
@@ -1771,7 +1652,7 @@ describe("crypto", () => {
         * https://spec.matrix.org/v1.6/client-server-api/#put_matrixclientv3useruseridaccount_datatype
         */
        async function awaitCrossSigningKeyUpload(key: string): Promise<Record<string, {}>> {
-            const content = await accountDataAccumulator.interceptSetAccountData(`m.cross_signing.${key}`);
+            const content = await accountDataAccumulator.waitForAccountData(`m.cross_signing.${key}`);
            return content.encrypted;
        }

@@ -1783,10 +1664,7 @@ describe("crypto", () => {
        async function awaitSecretStorageKeyStoredInAccountData(): Promise<string> {
            // eslint-disable-next-line no-constant-condition
            while (true) {
-                const content = await accountDataAccumulator.interceptSetAccountData(":type(m.secret_storage.*)", {
-                    repeat: 1,
-                    overwriteRoutes: true,
-                });
+                const content = await accountDataAccumulator.waitForAccountData("m.secret_storage.*");
                if (content.key) {
                    return content.key;
                }
@@ -1794,10 +1672,7 @@ describe("crypto", () => {
        }

        async function awaitMegolmBackupKeyUpload(): Promise<Record<string, {}>> {
-            const content = await accountDataAccumulator.interceptSetAccountData("m.megolm_backup.v1", {
-                repeat: 1,
-                overwriteRoutes: true,
-            });
+            const content = await accountDataAccumulator.waitForAccountData("m.megolm_backup.v1");
            return content.encrypted;
        }

@@ -1818,7 +1693,6 @@ describe("crypto", () => {
         * @param backupVersion - The version of the created backup
         */
        async function bootstrapSecurity(backupVersion: string): Promise<void> {
-            mockSetupCrossSigningRequests();
            mockSetupMegolmBackupRequests(backupVersion);

            // promise which will resolve when a `KeyBackupStatus` event is emitted with `enabled: true`
@@ -1897,6 +1771,7 @@ describe("crypto", () => {

            it("Should create a 4S key", async () => {
                accountDataAccumulator.interceptGetAccountData();
+                accountDataAccumulator.interceptSetAccountData();

                const awaitAccountData = awaitAccountDataUpdate("m.secret_storage.default_key");

@@ -2048,8 +1923,7 @@ describe("crypto", () => {

        describe("Manage Key Backup", () => {
            beforeEach(async () => {
-                // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-                jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+                vi.useFakeTimers();
            });

            it("Should be able to restore from 4S after bootstrap", async () => {
@@ -2066,29 +1940,23 @@ describe("crypto", () => {
                const newKey = testData.MEGOLM_SESSION_DATA;

                const awaitKeyUploaded = new Promise<KeyBackup>((resolve) => {
-                    fetchMock.put(
-                        "path:/_matrix/client/v3/room_keys/keys",
-                        (url, request) => {
-                            const uploadPayload: KeyBackup = JSON.parse((request.body as string) ?? "{}");
-                            resolve(uploadPayload);
-                            return {
-                                status: 200,
-                                body: {
-                                    count: 1,
-                                    etag: "abcdefg",
-                                },
-                            };
-                        },
-                        {
-                            overwriteRoutes: true,
-                        },
-                    );
+                    fetchMock.put("path:/_matrix/client/v3/room_keys/keys", (callLog) => {
+                        const uploadPayload: KeyBackup = JSON.parse((callLog.options.body as string) ?? "{}");
+                        resolve(uploadPayload);
+                        return {
+                            status: 200,
+                            body: {
+                                count: 1,
+                                etag: "abcdefg",
+                            },
+                        };
+                    });
                });

                await aliceClient.getCrypto()!.importRoomKeys([newKey]);

                // The backup loop waits a random amount of time to avoid different clients firing at the same time.
-                jest.runAllTimers();
+                vi.runAllTimers();

                const keyBackupData = await awaitKeyUploaded;

@@ -2116,40 +1984,33 @@ describe("crypto", () => {
                    fetchMock.delete(
                        "express:/_matrix/client/v3/room_keys/version/:version",
                        (url: string, options: RequestInit) => {
-                            fetchMock.get(
-                                "path:/_matrix/client/v3/room_keys/version",
-                                {
+                            fetchMock.modifyRoute("room-keys-version", {
+                                response: {
                                    status: 404,
                                    body: { errcode: "M_NOT_FOUND", error: "No current backup version." },
                                },
-                                { overwriteRoutes: true },
-                            );
+                            });
                            resolve();
                            return {};
                        },
-                        { overwriteRoutes: true },
                    );
                });

                const newVersion = "2";
-                fetchMock.post(
-                    "path:/_matrix/client/v3/room_keys/version",
-                    (url, request) => {
-                        const backupData: KeyBackupInfo = JSON.parse((request.body as string) ?? "{}");
+                fetchMock.modifyRoute("post-room-keys-version", {
+                    response: (callLog) => {
+                        const backupData: KeyBackupInfo = JSON.parse((callLog.options.body as string) ?? "{}");
                        backupData.version = newVersion;
                        backupData.count = 0;
                        backupData.etag = "zer";

                        // update get call with new version
-                        fetchMock.get("path:/_matrix/client/v3/room_keys/version", backupData, {
-                            overwriteRoutes: true,
-                        });
+                        fetchMock.modifyRoute("room-keys-version", { response: backupData });
                        return {
                            version: backupVersion,
                        };
                    },
-                    { overwriteRoutes: true },
-                );
+                });

                const newBackupStatusUpdate = new Promise<void>((resolve) => {
                    aliceClient.on(CryptoEvent.KeyBackupStatus, (enabled) => {
@@ -2204,6 +2065,7 @@ describe("crypto", () => {
            expect(hasCrossSigningKeysForUser).toBe(true);

            const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(BOB_TEST_USER_ID);
+            expect(verificationStatus.known).toBe(false); // We haven't actually stashed a copy of Alice's identity
            expect(verificationStatus.isVerified()).toBe(false);
            expect(verificationStatus.isCrossSigningVerified()).toBe(false);
            expect(verificationStatus.wasCrossSigningVerified()).toBe(false);
@@ -2211,15 +2073,15 @@ describe("crypto", () => {
        });

        it("Cross signing keys are available for a tracked user", async () => {
-            // Process Alice keys, old crypto has a sleep(5ms) during the process
-            await jest.advanceTimersByTimeAsync(5);
+            // Process Alice keys
            await flushPromises();

            // Alice is the local user and should be tracked !
            const hasCrossSigningKeysForUser = await aliceClient.getCrypto()!.userHasCrossSigningKeys(TEST_USER_ID);
            expect(hasCrossSigningKeysForUser).toBe(true);

-            const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(BOB_TEST_USER_ID);
+            const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(TEST_USER_ID);
+            expect(verificationStatus.known).toBe(true);
            expect(verificationStatus.isVerified()).toBe(false);
            expect(verificationStatus.isCrossSigningVerified()).toBe(false);
            expect(verificationStatus.wasCrossSigningVerified()).toBe(false);
@@ -2230,7 +2092,8 @@ describe("crypto", () => {
            const hasCrossSigningKeysForUser = await aliceClient.getCrypto()!.userHasCrossSigningKeys("@unknown:xyz");
            expect(hasCrossSigningKeysForUser).toBe(false);

-            const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(BOB_TEST_USER_ID);
+            const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus("@unknown:xyz");
+            expect(verificationStatus.known).toBe(false);
            expect(verificationStatus.isVerified()).toBe(false);
            expect(verificationStatus.isCrossSigningVerified()).toBe(false);
            expect(verificationStatus.wasCrossSigningVerified()).toBe(false);
@@ -2260,6 +2123,7 @@ describe("crypto", () => {

            {
                const verificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(BOB_TEST_USER_ID);
+                expect(verificationStatus.known).toBe(true);
                expect(verificationStatus.isVerified()).toBe(false);
                expect(verificationStatus.isCrossSigningVerified()).toBe(false);
                expect(verificationStatus.wasCrossSigningVerified()).toBe(false);
@@ -2300,6 +2164,7 @@ describe("crypto", () => {
            client2?.stopClient();
        });

+        // eslint-disable-next-line @vitest/expect-expect
        test("Sending a message in a room where the server is hiding the state event does not send a plaintext event", async () => {
            // Alice is in an encrypted room
            const encryptionState = mkEncryptionEvent({ algorithm: "m.megolm.v1.aes-sha2" });
@@ -2307,7 +2172,7 @@ 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);
@@ -2328,7 +2193,7 @@ 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
@@ -2347,16 +2212,17 @@ 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);
        });

+        // eslint-disable-next-line @vitest/expect-expect
        test("Changes to the rotation period should be ignored after a client restart", async () => {
            // Alice is in an encrypted room, where the rotation period is set to 2 messages
            const encryptionState = mkEncryptionEvent({ algorithm: "m.megolm.v1.aes-sha2", rotation_period_msgs: 2 });
@@ -2364,7 +2230,7 @@ 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);
@@ -2450,4 +2316,107 @@ describe("crypto", () => {
            );
        }
    });
+
+    describe("secret pushing", () => {
+        it("should push a new backup key when a new backup key is set", async () => {
+            // setup: alice has another device, DEVICE_ID, which is verified
+            const crypto = aliceClient.getCrypto()!;
+            expectAliceKeyQuery(getTestKeysQueryResponse("@alice:localhost"));
+            await startClientAndAwaitFirstSync();
+            const devices = await aliceClient.getCrypto()!.getUserDeviceInfo(["@alice:localhost"]);
+            expect(devices.get("@alice:localhost")!.keys()).toContain("DEVICE_ID");
+            await crypto.setDeviceVerified("@alice:localhost", "DEVICE_ID");
+
+            expectAliceKeyClaim(getTestKeysClaimResponse("@alice:localhost"));
+
+            // when we set a new backup key
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", {
+                status: 404,
+                body: { errcode: "M_NOT_FOUND", error: "No current backup version." },
+            });
+            fetchMock.post("path:/_matrix/client/v3/room_keys/version", {
+                status: 200,
+                body: { version: "1" },
+            });
+            const secretPushPromise = new Promise<any>((resolve) => {
+                fetchMock.putOnce(new RegExp("/sendToDevice/m.room.encrypted/"), (callLog): RouteResponse => {
+                    const content = JSON.parse(callLog.options.body as string);
+                    resolve(content);
+                    return {};
+                });
+            });
+
+            await crypto.resetKeyBackup();
+
+            // we expect the other device to get a secret push
+            const content = await secretPushPromise;
+            const curve25519key = JSON.parse(testOlmAccount.identity_keys()).curve25519;
+            const ciphertext = content.messages["@alice:localhost"].DEVICE_ID.ciphertext[curve25519key];
+            const olmSession = new Olm.Session();
+            olmSession.create_inbound(testOlmAccount, ciphertext.body);
+            const decrypted = JSON.parse(olmSession.decrypt(0, ciphertext.body));
+            expect(decrypted.type).toBe("io.element.msc4385.secret.push");
+            expect(decrypted.content.name).toBe("m.megolm_backup.v1");
+        });
+
+        it("should receive pushed backup key", async () => {
+            // setup: alice has another device, DEVICE_ID, which is verified,
+            // and has a key backup set up and signed by DEVICE_ID
+            const crypto = aliceClient.getCrypto()!;
+            expectAliceKeyQuery(getTestKeysQueryResponse("@alice:localhost"));
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            await startClientAndAwaitFirstSync();
+            const devices = await aliceClient.getCrypto()!.getUserDeviceInfo(["@alice:localhost"]);
+            expect(devices.get("@alice:localhost")!.keys()).toContain("DEVICE_ID");
+            await crypto.setDeviceVerified("@alice:localhost", "DEVICE_ID");
+
+            expectAliceKeyClaim(getTestKeysClaimResponse("@alice:localhost"));
+
+            // after we push the backup key to alice...
+
+            const senderIdentityKeys = JSON.parse(testOlmAccount.identity_keys());
+            const aliceDeviceKeys = await crypto.getOwnDeviceKeys();
+            const p2pSession = await createOlmSession(testOlmAccount, keyReceiver);
+            const secretPush = encryptOlmEvent({
+                sender: "@alice:localhost",
+                senderKey: senderIdentityKeys.curve25519,
+                senderSigningKey: senderIdentityKeys.ed25519,
+                p2pSession,
+                recipient: "@alice:localhost",
+                recipientCurve25519Key: aliceDeviceKeys.curve25519,
+                recipientEd25519Key: aliceDeviceKeys.ed25519,
+                plaincontent: {
+                    secret: testData.BACKUP_DECRYPTION_KEY_BASE64,
+                    name: "m.megolm_backup.v1",
+                },
+                plaintype: "io.element.msc4385.secret.push",
+            });
+
+            const syncResponse = {
+                next_batch: 1,
+                to_device: {
+                    events: [secretPush],
+                },
+            };
+
+            const backupKeyReceivedPromise = new Promise<string>((resolve) => {
+                aliceClient.on(CryptoEvent.KeyBackupDecryptionKeyCached, resolve);
+            });
+            const keyBackupEnabledPromise = new Promise<void>((resolve) => {
+                aliceClient.on(CryptoEvent.KeyBackupStatus, (enabled) => {
+                    if (enabled) {
+                        resolve();
+                    }
+                });
+            });
+
+            syncResponder.sendOrQueueSyncResponse(syncResponse);
+            await syncPromise(aliceClient);
+
+            // alice should be using backup now
+            expect(await backupKeyReceivedPromise).toBe(testData.SIGNED_BACKUP_DATA.version);
+            await keyBackupEnabledPromise;
+            expect(await crypto.getActiveSessionBackupVersion()).toBe(testData.SIGNED_BACKUP_DATA.version);
+        });
+    });
 });
@@ -15,9 +15,11 @@ limitations under the License.
 */

 import "fake-indexeddb/auto";
-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";
+import { type CallLog } from "fetch-mock";
+import debug from "debug";

-import { ClientEvent, createClient, type MatrixClient, MatrixEvent } from "../../../src";
+import { ClientEvent, createClient, DebugLogger, type MatrixClient, MatrixEvent } from "../../../src";
 import { CryptoEvent } from "../../../src/crypto-api/index";
 import { type RustCrypto } from "../../../src/rust-crypto/rust-crypto";
 import { type AddSecretStorageKeyOpts } from "../../../src/secret-storage";
@@ -27,7 +29,7 @@ import { emitPromise, EventCounter } from "../../test-utils/test-utils";

 describe("Device dehydration", () => {
    it("should rehydrate and dehydrate a device", async () => {
-        jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+        vi.useFakeTimers();

        const matrixClient = createClient({
            baseUrl: "http://test.server",
@@ -38,6 +40,7 @@ describe("Device dehydration", () => {
                    return [[...Object.keys(keys.keys)][0], new Uint8Array(32)];
                },
            },
+            logger: new DebugLogger(debug(`matrix-js-sdk:dehydration`)),
        });

        await initializeSecretStorage(matrixClient, "@alice:localhost", "http://test.server");
@@ -57,28 +60,35 @@ describe("Device dehydration", () => {
        });

        const crypto = matrixClient.getCrypto()!;
-        fetchMock.config.overwriteRoutes = true;

        // start dehydration -- we start with no dehydrated device, and we
        // store the dehydrated device that we create
-        fetchMock.get("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", {
-            status: 404,
-            body: {
-                errcode: "M_NOT_FOUND",
-                error: "Not found",
+        fetchMock.get(
+            "path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device",
+            {
+                status: 404,
+                body: {
+                    errcode: "M_NOT_FOUND",
+                    error: "Not found",
+                },
            },
-        });
+            { name: "get-dehydrated-device" },
+        );
        let dehydratedDeviceBody: any;
        let dehydrationCount = 0;
        let resolveDehydrationPromise: () => void;
-        fetchMock.put("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", (_, opts) => {
-            dehydratedDeviceBody = JSON.parse(opts.body as string);
-            dehydrationCount++;
-            if (resolveDehydrationPromise) {
-                resolveDehydrationPromise();
-            }
-            return {};
-        });
+        fetchMock.put(
+            "path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device",
+            (callLog) => {
+                dehydratedDeviceBody = JSON.parse(callLog.options.body as string);
+                dehydrationCount++;
+                if (resolveDehydrationPromise) {
+                    resolveDehydrationPromise();
+                }
+                return {};
+            },
+            { name: "put-dehydrated-device" },
+        );
        await crypto.startDehydration();

        expect(dehydrationCount).toEqual(1);
@@ -89,7 +99,7 @@ describe("Device dehydration", () => {
        const dehydrationPromise = new Promise<void>((resolve, reject) => {
            resolveDehydrationPromise = resolve;
        });
-        jest.advanceTimersByTime(7 * 24 * 60 * 60 * 1000);
+        vi.advanceTimersByTime(7 * 24 * 60 * 60 * 1000);
        await dehydrationPromise;

        expect(dehydrationKeyCachedEventCounter.counter).toEqual(1);
@@ -99,16 +109,18 @@ describe("Device dehydration", () => {
        // restart dehydration -- rehydrate the device that we created above,
        // and create a new dehydrated device.  We also set `createNewKey`, so
        // a new dehydration key will be set
-        fetchMock.get("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", {
-            device_id: dehydratedDeviceBody.device_id,
-            device_data: dehydratedDeviceBody.device_data,
+        fetchMock.modifyRoute("get-dehydrated-device", {
+            response: {
+                device_id: dehydratedDeviceBody.device_id,
+                device_data: dehydratedDeviceBody.device_data,
+            },
        });
-        const eventsResponse = jest.fn((url, opts) => {
+        const eventsResponse = vi.fn((callLog: CallLog) => {
            // rehydrating should make two calls to the /events endpoint.
            // The first time will return a single event, and the second
            // time will return no events (which will signal to the
            // rehydration function that it can stop)
-            const body = JSON.parse(opts.body as string);
+            const body = JSON.parse(callLog.options.body as string);
            const nextBatch = body.next_batch ?? "0";
            const events = nextBatch === "0" ? [{ sender: "@alice:localhost", type: "m.dummy", content: {} }] : [];
            return {
@@ -133,28 +145,30 @@ describe("Device dehydration", () => {
        expect(dehydrationKeyCachedEventCounter.counter).toEqual(2);

        // test that if we get an error when we try to rotate, it emits an event
-        fetchMock.put("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", {
-            status: 500,
-            body: {
-                errcode: "M_UNKNOWN",
-                error: "Unknown error",
+        fetchMock.modifyRoute("put-dehydrated-device", {
+            response: {
+                status: 500,
+                body: {
+                    errcode: "M_UNKNOWN",
+                    error: "Unknown error",
+                },
            },
        });
        const rotationErrorEventPromise = emitPromise(matrixClient, CryptoEvent.DehydratedDeviceRotationError);
-        jest.advanceTimersByTime(7 * 24 * 60 * 60 * 1000);
+        vi.advanceTimersByTime(7 * 24 * 60 * 60 * 1000);
        await rotationErrorEventPromise;

        // Restart dehydration, but return an error for GET /dehydrated_device so that rehydration fails.
-        fetchMock.get("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", {
-            status: 500,
-            body: {
-                errcode: "M_UNKNOWN",
-                error: "Unknown error",
+        fetchMock.modifyRoute("get-dehydrated-device", {
+            response: {
+                status: 500,
+                body: {
+                    errcode: "M_UNKNOWN",
+                    error: "Unknown error",
+                },
            },
        });
-        fetchMock.put("path:/_matrix/client/unstable/org.matrix.msc3814.v1/dehydrated_device", (_, opts) => {
-            return {};
-        });
+        fetchMock.modifyRoute("put-dehydrated-device", { response: { body: {} } });
        const rehydrationErrorEventPromise = emitPromise(matrixClient, CryptoEvent.RehydrationError);
        await crypto.startDehydration(true);
        await rehydrationErrorEventPromise;
@@ -179,11 +193,9 @@ async function initializeSecretStorage(
    const e2eKeyReceiver = new E2EKeyReceiver(homeserverUrl);
    const e2eKeyResponder = new E2EKeyResponder(homeserverUrl);
    e2eKeyResponder.addKeyReceiver(userId, e2eKeyReceiver);
-    fetchMock.post("path:/_matrix/client/v3/keys/device_signing/upload", {});
-    fetchMock.post("path:/_matrix/client/v3/keys/signatures/upload", {});
    const accountData: Map<string, object> = new Map();
-    fetchMock.get("glob:http://*/_matrix/client/v3/user/*/account_data/*", (url, opts) => {
-        const name = url.split("/").pop()!;
+    fetchMock.get("glob:http://*/_matrix/client/v3/user/*/account_data/*", (callLog) => {
+        const name = callLog.url.split("/").pop()!;
        const value = accountData.get(name);
        if (value) {
            return value;
@@ -197,9 +209,9 @@ async function initializeSecretStorage(
            };
        }
    });
-    fetchMock.put("glob:http://*/_matrix/client/v3/user/*/account_data/*", (url, opts) => {
-        const name = url.split("/").pop()!;
-        const value = JSON.parse(opts.body as string);
+    fetchMock.put("glob:http://*/_matrix/client/v3/user/*/account_data/*", (callLog) => {
+        const name = callLog.url.split("/").pop()!;
+        const value = JSON.parse(callLog.options.body as string);
        accountData.set(name, value);
        matrixClient.emit(ClientEvent.AccountData, new MatrixEvent({ type: name, content: value }));
        return {};
@@ -14,14 +14,15 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
-import { type Mocked } from "jest-mock";
+import { type Mocked } from "vitest";

 import {
    createClient,
    encodeBase64,
+    type IContent,
    type ICreateClientOpts,
    type IEvent,
    type IMegolmSessionData,
@@ -36,7 +37,13 @@ import { advanceTimersUntil, awaitDecryption, syncPromise } from "../../test-uti
 import * as testData from "../../test-utils/test-data";
 import { type KeyBackupInfo, type KeyBackupSession } from "../../../src/crypto-api/keybackup";
 import { flushPromises } from "../../test-utils/flushPromises";
-import { decodeRecoveryKey, DecryptionFailureCode, CryptoEvent, type CryptoApi } from "../../../src/crypto-api";
+import {
+    decodeRecoveryKey,
+    DecryptionFailureCode,
+    CryptoEvent,
+    type CryptoApi,
+    DecryptionKeyDoesNotMatchError,
+} from "../../../src/crypto-api";
 import { type KeyBackup } from "../../../src/rust-crypto/backup.ts";

 const ROOM_ID = testData.TEST_ROOM_ID;
@@ -69,10 +76,11 @@ function mockUploadEmitter(
    expectedVersion: string,
 ): TypedEventEmitter<MockKeyUploadEvent, MockKeyUploadEventHandlerMap> {
    const emitter = new TypedEventEmitter();
+    fetchMock.removeRoute("mock-upload-emitter");
    fetchMock.put(
        "path:/_matrix/client/v3/room_keys/keys",
-        (url, request) => {
-            const version = new URLSearchParams(new URL(url).search).get("version");
+        (callLog) => {
+            const version = new URLSearchParams(new URL(callLog.url).search).get("version");
            if (version != expectedVersion) {
                return {
                    status: 403,
@@ -83,7 +91,7 @@ function mockUploadEmitter(
                    },
                };
            }
-            const uploadPayload: KeyBackup = JSON.parse((request.body as string) ?? "{}");
+            const uploadPayload: KeyBackup = JSON.parse((callLog.options.body as string) ?? "{}");
            let count = 0;
            for (const [roomId, value] of Object.entries(uploadPayload.rooms)) {
                for (const sessionId of Object.keys(value.sessions)) {
@@ -99,9 +107,7 @@ function mockUploadEmitter(
                },
            };
        },
-        {
-            overwriteRoutes: true,
-        },
+        { name: "mock-upload-emitter" },
    );
    return emitter;
 }
@@ -117,12 +123,10 @@ describe("megolm-keys backup", () => {
    let e2eKeyResponder: E2EKeyResponder;

    beforeEach(async () => {
-        // We want to use fake timers, but the wasm bindings of matrix-sdk-crypto rely on a working `queueMicrotask`.
-        jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+        vi.useFakeTimers();

        // anything that we don't have a specific matcher for silently returns a 404
        fetchMock.catch(404);
-        fetchMock.config.warnOnFallback = false;

        mockInitialApiRequests(TEST_HOMESERVER_URL);
        syncResponder = new SyncResponder(TEST_HOMESERVER_URL);
@@ -133,15 +137,12 @@ describe("megolm-keys backup", () => {
    });

    afterEach(async () => {
-        if (aliceClient !== undefined) {
-            await aliceClient.stopClient();
-        }
+        aliceClient?.stopClient();

        // Allow in-flight things to complete before we tear down the test
-        await jest.runAllTimersAsync();
+        await vi.runAllTimersAsync();

-        fetchMock.mockReset();
-        jest.restoreAllMocks();
+        vi.restoreAllMocks();
    });

    async function initTestClient(opts: Partial<ICreateClientOpts> = {}): Promise<MatrixClient> {
@@ -207,9 +208,9 @@ describe("megolm-keys backup", () => {
        );

        it("Alice checks key backups when receiving a message she can't decrypt", async () => {
-            fetchMock.get("express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id", (url, request) => {
+            fetchMock.get("express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id", (callLog) => {
                // check that the version is correct
-                const version = new URLSearchParams(new URL(url).search).get("version");
+                const version = new URLSearchParams(new URL(callLog.url).search).get("version");
                if (version == "1") {
                    return testData.CURVE25519_KEY_BACKUP_DATA;
                } else {
@@ -237,11 +238,11 @@ describe("megolm-keys backup", () => {

            // Eventually, decryption succeeds.
            await awaitDecryption(event, { waitOnDecryptionFailure: true });
-            expect(event.getContent()).toEqual(testData.CLEAR_EVENT.content);
+            expect(event.getContent<IContent>()).toEqual(testData.CLEAR_EVENT.content);
        });

        it("handles error on backup query gracefully", async () => {
-            jest.spyOn(console, "error").mockImplementation(() => {});
+            vi.spyOn(console, "error").mockImplementation(() => {});

            fetchMock.get(
                "express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id",
@@ -253,9 +254,9 @@ describe("megolm-keys backup", () => {
            syncResponder.sendOrQueueSyncResponse(SYNC_RESPONSE);
            await flushBackupRequest();

-            const calls = fetchMock.calls("getKey");
+            const calls = fetchMock.callHistory.calls("getKey");
            expect(calls.length).toEqual(1);
-            expect(calls[0][0]).toEqual(EXPECTED_URL);
+            expect(calls[0].url).toEqual(EXPECTED_URL);

            await flushBackupRequest();

@@ -274,11 +275,11 @@ describe("megolm-keys backup", () => {
            // Send Alice a message that she won't be able to decrypt
            syncResponder.sendOrQueueSyncResponse(SYNC_RESPONSE);
            await flushBackupRequest();
-            const calls = fetchMock.calls("getKey");
+            const calls = fetchMock.callHistory.calls("getKey");
            expect(calls.length).toEqual(1);
-            expect(calls[0][0]).toEqual(EXPECTED_URL);
+            expect(calls[0].url).toEqual(EXPECTED_URL);

-            fetchMock.resetHistory();
+            fetchMock.clearHistory();

            // another message
            const event2 = { ...testData.ENCRYPTED_EVENT, event_id: "$event2" };
@@ -288,7 +289,7 @@ describe("megolm-keys backup", () => {
            };
            syncResponder.sendOrQueueSyncResponse(syncResponse2);
            await flushBackupRequest();
-            expect(fetchMock.calls("getKey").length).toEqual(0);
+            expect(fetchMock.callHistory.calls("getKey").length).toEqual(0);
        });
    });

@@ -364,9 +365,9 @@ describe("megolm-keys backup", () => {
        }

        it("Should import full backup in chunks", async function () {
-            const importMockImpl = jest.fn();
+            const importMockImpl = vi.fn();
            // @ts-ignore - mock a private method for testing purpose
-            jest.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            vi.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);

            // We need several rooms with several sessions to test chunking
            const { response, expectedTotal } = createBackupDownloadResponse([45, 300, 345, 12, 130]);
@@ -380,7 +381,7 @@ describe("megolm-keys backup", () => {
                check!.backupInfo!.version!,
            );

-            const progressCallback = jest.fn();
+            const progressCallback = vi.fn();
            const result = await aliceCrypto.restoreKeyBackup({
                progressCallback,
            });
@@ -417,7 +418,7 @@ describe("megolm-keys backup", () => {
        });

        it("Should continue to process backup if a chunk import fails and report failures", async function () {
-            const importMockImpl = jest
+            const importMockImpl = vi
                .fn()
                .mockImplementationOnce(() => {
                    // Fail to import first chunk
@@ -427,7 +428,7 @@ describe("megolm-keys backup", () => {
                .mockResolvedValue(undefined);

            // @ts-ignore - mock a private method for testing purpose
-            jest.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);
+            vi.spyOn(aliceCrypto.backupManager, "importBackedUpRoomKeys").mockImplementation(importMockImpl);

            const { response, expectedTotal } = createBackupDownloadResponse([100, 300]);

@@ -439,7 +440,7 @@ describe("megolm-keys backup", () => {
                check!.backupInfo!.version!,
            );

-            const progressCallback = jest.fn();
+            const progressCallback = vi.fn();
            const result = await aliceCrypto.restoreKeyBackup({ progressCallback });

            expect(result.total).toStrictEqual(expectedTotal);
@@ -463,13 +464,13 @@ describe("megolm-keys backup", () => {

        it("Should continue if some keys fails to decrypt", async function () {
            // @ts-ignore - mock a private method for testing purpose
-            aliceCrypto.importBackedUpRoomKeys = jest.fn();
+            aliceCrypto.importBackedUpRoomKeys = vi.fn();

            const decryptionFailureCount = 2;

            const mockDecryptor = {
                // DecryptSessions does not reject on decryption failure, but just skip the key
-                decryptSessions: jest.fn().mockImplementation((sessions) => {
+                decryptSessions: vi.fn().mockImplementation((sessions) => {
                    // simulate fail to decrypt 2 keys out of all
                    const decrypted = [];
                    const keys = Object.keys(sessions);
@@ -480,11 +481,11 @@ describe("megolm-keys backup", () => {
                    }
                    return decrypted;
                }),
-                free: jest.fn(),
+                free: vi.fn(),
            };

            // @ts-ignore - mock a private method for testing purpose
-            aliceCrypto.getBackupDecryptor = jest.fn().mockResolvedValue(mockDecryptor);
+            aliceCrypto.getBackupDecryptor = vi.fn().mockResolvedValue(mockDecryptor);

            const { response, expectedTotal } = createBackupDownloadResponse([100]);

@@ -505,17 +506,12 @@ describe("megolm-keys backup", () => {

        it("Should get the decryption key from the secret storage and restore the key backup", async function () {
            // @ts-ignore - mock a private method for testing purpose
-            jest.spyOn(aliceCrypto.secretStorage, "get").mockResolvedValue(testData.BACKUP_DECRYPTION_KEY_BASE64);
+            vi.spyOn(aliceCrypto.secretStorage, "get").mockResolvedValue(testData.BACKUP_DECRYPTION_KEY_BASE64);

-            const fullBackup = {
-                rooms: {
-                    [ROOM_ID]: {
-                        sessions: {
-                            [testData.MEGOLM_SESSION_DATA.session_id]: testData.CURVE25519_KEY_BACKUP_DATA,
-                        },
-                    },
-                },
-            };
+            const fullBackup = createFullBackup(
+                testData.MEGOLM_SESSION_DATA.session_id,
+                testData.CURVE25519_KEY_BACKUP_DATA,
+            );
            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", fullBackup);

            await aliceCrypto.loadSessionBackupPrivateKeyFromSecretStorage();
@@ -526,15 +522,44 @@ describe("megolm-keys backup", () => {
            expect(result.imported).toStrictEqual(1);
        });

+        it("Should throw an error if the decryption key does not match the backup", async function () {
+            // Given the stored backup decryption key does not match the public backup info
+            // @ts-ignore - mock a private method for testing purpose
+            vi.spyOn(aliceCrypto.secretStorage, "get").mockResolvedValue(testData.BACKUP_DECRYPTION_KEY_BASE64_ALT);
+
+            const fullBackup = createFullBackup(
+                testData.MEGOLM_SESSION_DATA.session_id,
+                testData.CURVE25519_KEY_BACKUP_DATA,
+            );
+            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", fullBackup);
+
+            // When we load that key, we throw because the keys don't match
+            await expect(aliceCrypto.loadSessionBackupPrivateKeyFromSecretStorage()).rejects.toThrow(
+                DecryptionKeyDoesNotMatchError,
+            );
+        });
+
        it("Should throw an error if the decryption key is not found in cache", async () => {
            await expect(aliceCrypto.restoreKeyBackup()).rejects.toThrow("No decryption key found in crypto store");
        });
+
+        function createFullBackup(sessionId: string, data: KeyBackupSession) {
+            return {
+                rooms: {
+                    [ROOM_ID]: {
+                        sessions: {
+                            [sessionId]: data,
+                        },
+                    },
+                },
+            };
+        }
    });

    describe("backupLoop", () => {
        it("Alice should upload known keys when backup is enabled", async function () {
            // 404 means that there is no active backup
-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", 404);
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", 404, { name: "room-keys-version" });

            aliceClient = await initTestClient();
            const aliceCrypto = aliceClient.getCrypto()!;
@@ -571,8 +596,8 @@ describe("megolm-keys backup", () => {
                });
            });

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
-                overwriteRoutes: true,
+            fetchMock.modifyRoute("room-keys-version", {
+                response: { status: 200, body: testData.SIGNED_BACKUP_DATA },
            });

            const result = await aliceCrypto.checkKeyBackupAndEnable();
@@ -581,7 +606,7 @@ describe("megolm-keys backup", () => {
            await aliceCrypto.importRoomKeys(someRoomKeys);

            // The backup loop is waiting a random amount of time to avoid different clients firing at the same time.
-            jest.runAllTimers();
+            vi.runAllTimers();

            await Promise.all(uploadPromises);

@@ -605,7 +630,7 @@ describe("megolm-keys backup", () => {

            await aliceCrypto.importRoomKeys([newKey]);

-            jest.runAllTimers();
+            vi.runAllTimers();
            await newKeyUploadPromise;
        });

@@ -630,7 +655,7 @@ describe("megolm-keys backup", () => {
            const someRoomKeys = testData.MEGOLM_SESSION_DATA_ARRAY;

            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
-                overwriteRoutes: true,
+                name: "room-keys-version",
            });

            const result = await aliceCrypto.checkKeyBackupAndEnable();
@@ -640,7 +665,7 @@ describe("megolm-keys backup", () => {
            await aliceCrypto.importRoomKeys(someRoomKeys);

            // The backup loop is waiting a random amount of time to avoid different clients firing at the same time.
-            jest.runAllTimers();
+            vi.runAllTimers();

            // wait for all keys to be backed up
            await remainingZeroPromise;
@@ -651,10 +676,7 @@ describe("megolm-keys backup", () => {
            newBackup.version = newBackupVersion;

            // Let's simulate that a new backup is available by returning error code on key upload
-
-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", newBackup, {
-                overwriteRoutes: true,
-            });
+            fetchMock.modifyRoute("room-keys-version", { response: newBackup });

            // If we import a new key the loop will try to upload to old version, it will
            // fail then check the current version and switch if trusted
@@ -697,12 +719,12 @@ describe("megolm-keys backup", () => {

            await aliceCrypto.importRoomKeys([newKey]);

-            jest.runAllTimers();
+            vi.runAllTimers();

            await disableOldBackup;
            await enableNewBackup;

-            jest.runAllTimers();
+            vi.runAllTimers();

            await Promise.all(uploadPromises);
            await newKeyUploadPromise;
@@ -717,22 +739,14 @@ describe("megolm-keys backup", () => {
            await waitForDeviceList();
            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
-                overwriteRoutes: true,
-            });
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

            // on the first key upload attempt, simulate a network failure
            const failurePromise = new Promise((resolve) => {
-                fetchMock.put(
-                    "path:/_matrix/client/v3/room_keys/keys",
-                    () => {
-                        resolve(undefined);
-                        throw new TypeError(`Failed to fetch`);
-                    },
-                    {
-                        overwriteRoutes: true,
-                    },
-                );
+                fetchMock.putOnce("path:/_matrix/client/v3/room_keys/keys", () => {
+                    resolve(undefined);
+                    throw new TypeError(`Failed to fetch`);
+                });
            });

            // kick the import loop off and wait for the failed request
@@ -741,27 +755,21 @@ describe("megolm-keys backup", () => {

            const result = await aliceCrypto.checkKeyBackupAndEnable();
            expect(result).toBeTruthy();
-            jest.advanceTimersByTime(10 * 60 * 1000);
+            vi.advanceTimersByTime(10 * 60 * 1000);
            await failurePromise;

            // Fix the endpoint to do successful uploads
            const successPromise = new Promise((resolve) => {
-                fetchMock.put(
-                    "path:/_matrix/client/v3/room_keys/keys",
-                    () => {
-                        resolve(undefined);
-                        return {
-                            status: 200,
-                            body: {
-                                count: 2,
-                                etag: "abcdefg",
-                            },
-                        };
-                    },
-                    {
-                        overwriteRoutes: true,
-                    },
-                );
+                fetchMock.putOnce("path:/_matrix/client/v3/room_keys/keys", () => {
+                    resolve(undefined);
+                    return {
+                        status: 200,
+                        body: {
+                            count: 2,
+                            etag: "abcdefg",
+                        },
+                    };
+                });
            });

            // check that a `KeyBackupSessionsRemaining` event is emitted with `remaining == 0`
@@ -774,7 +782,7 @@ describe("megolm-keys backup", () => {
            });

            // run the timers, which will make the backup loop redo the request
-            await jest.advanceTimersByTimeAsync(10 * 60 * 1000);
+            await vi.advanceTimersByTimeAsync(10 * 60 * 1000);
            await successPromise;
            await allKeysUploadedPromise;
        });
@@ -782,7 +790,7 @@ describe("megolm-keys backup", () => {

    it("getActiveSessionBackupVersion() should give correct result", async function () {
        // 404 means that there is no active backup
-        fetchMock.get("express:/_matrix/client/v3/room_keys/version", 404);
+        fetchMock.getOnce("express:/_matrix/client/v3/room_keys/version", 404);

        aliceClient = await initTestClient();
        const aliceCrypto = aliceClient.getCrypto()!;
@@ -801,9 +809,7 @@ describe("megolm-keys backup", () => {
        // Serve a backup with no trusted signature
        const unsignedBackup = JSON.parse(JSON.stringify(testData.SIGNED_BACKUP_DATA));
        delete unsignedBackup.auth_data.signatures;
-        fetchMock.get("express:/_matrix/client/v3/room_keys/version", unsignedBackup, {
-            overwriteRoutes: true,
-        });
+        fetchMock.getOnce("express:/_matrix/client/v3/room_keys/version", unsignedBackup);

        const checked = await aliceCrypto.checkKeyBackupAndEnable();
        expect(checked?.backupInfo?.version).toStrictEqual(unsignedBackup.version);
@@ -813,9 +819,7 @@ describe("megolm-keys backup", () => {
        expect(backupStatus).toBeNull();

        // Add a valid signature to the backup
-        fetchMock.get("express:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
-            overwriteRoutes: true,
-        });
+        fetchMock.getOnce("express:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

        // check that signalling is working
        const backupPromise = new Promise<void>((resolve, reject) => {
@@ -837,7 +841,7 @@ describe("megolm-keys backup", () => {

    it("getKeyBackupInfo() should not return a backup if the active backup has been deleted", async () => {
        // 404 means that there is no active backup
-        fetchMock.get("express:/_matrix/client/v3/room_keys/version", 404);
+        fetchMock.getOnce("express:/_matrix/client/v3/room_keys/version", 404);
        fetchMock.delete(`express:/_matrix/client/v3/room_keys/version/${testData.SIGNED_BACKUP_DATA.version}`, {});

        aliceClient = await initTestClient();
@@ -853,11 +857,9 @@ describe("megolm-keys backup", () => {
        expect(await aliceCrypto.getKeyBackupInfo()).toBeNull();

        // Return now the backup
-        fetchMock.get("express:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
-            overwriteRoutes: true,
-        });
+        fetchMock.getOnce("express:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

-        expect(await aliceCrypto.getKeyBackupInfo()).toStrictEqual(testData.SIGNED_BACKUP_DATA);
+        expect(await aliceCrypto.getKeyBackupInfo()).toMatchObject(testData.SIGNED_BACKUP_DATA);

        // Delete the backup and we are expecting the key backup to be disabled
        const keyBackupStatus = Promise.withResolvers<boolean>();
@@ -991,7 +993,7 @@ describe("megolm-keys backup", () => {
            await waitForDeviceList();
            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

            const result = await aliceCrypto.checkKeyBackupAndEnable();
            expect(result).toBeTruthy();
@@ -1001,9 +1003,7 @@ describe("megolm-keys backup", () => {
            delete unsignedBackup.auth_data.signatures;
            unsignedBackup.version = "2";

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", unsignedBackup, {
-                overwriteRoutes: true,
-            });
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", unsignedBackup);

            await aliceCrypto.checkKeyBackupAndEnable();
            expect(await aliceCrypto.getActiveSessionBackupVersion()).toBeNull();
@@ -1018,7 +1018,7 @@ describe("megolm-keys backup", () => {
            await waitForDeviceList();
            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

            const result = await aliceCrypto.checkKeyBackupAndEnable();
            expect(result).toBeTruthy();
@@ -1028,9 +1028,7 @@ describe("megolm-keys backup", () => {
            const newBackup = JSON.parse(JSON.stringify(testData.SIGNED_BACKUP_DATA));
            newBackup.version = newBackupVersion;

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", newBackup, {
-                overwriteRoutes: true,
-            });
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", newBackup);

            await aliceCrypto.checkKeyBackupAndEnable();
            expect(await aliceCrypto.getActiveSessionBackupVersion()).toEqual(newBackupVersion);
@@ -1045,25 +1043,19 @@ describe("megolm-keys backup", () => {
            await waitForDeviceList();
            await aliceCrypto.setDeviceVerified(testData.TEST_USER_ID, testData.TEST_DEVICE_ID);

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);

            const result = await aliceCrypto.checkKeyBackupAndEnable();
            expect(result).toBeTruthy();
            expect(await aliceCrypto.getActiveSessionBackupVersion()).toEqual(testData.SIGNED_BACKUP_DATA.version);

-            fetchMock.get(
-                "path:/_matrix/client/v3/room_keys/version",
-                {
-                    status: 404,
-                    body: {
-                        errcode: "M_NOT_FOUND",
-                        error: "No backup found",
-                    },
+            fetchMock.getOnce("path:/_matrix/client/v3/room_keys/version", {
+                status: 404,
+                body: {
+                    errcode: "M_NOT_FOUND",
+                    error: "No backup found",
                },
-                {
-                    overwriteRoutes: true,
-                },
-            );
+            });
            const noResult = await aliceCrypto.checkKeyBackupAndEnable();
            expect(noResult).toBeNull();
            expect(await aliceCrypto.getActiveSessionBackupVersion()).toBeNull();
@@ -1072,10 +1064,12 @@ describe("megolm-keys backup", () => {

    describe("Backup Changed from other sessions", () => {
        beforeEach(async () => {
-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA);
+            fetchMock.get("path:/_matrix/client/v3/room_keys/version", testData.SIGNED_BACKUP_DATA, {
+                name: "room-keys-version",
+            });

            // ignore requests to send room key requests
-            fetchMock.put("express:/_matrix/client/v3/sendToDevice/m.room_key_request/:request_id", {});
+            fetchMock.getOnce("express:/_matrix/client/v3/sendToDevice/m.room_key_request/:request_id", {});

            aliceClient = await initTestClient();
            const aliceCrypto = aliceClient.getCrypto()!;
@@ -1108,9 +1102,9 @@ describe("megolm-keys backup", () => {

            fetchMock.get(
                "express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id",
-                (url, request) => {
+                (callLog) => {
                    // check that the version is correct
-                    const version = new URLSearchParams(new URL(url).search).get("version");
+                    const version = new URLSearchParams(new URL(callLog.url).search).get("version");
                    if (version == "1") {
                        return testData.CURVE25519_KEY_BACKUP_DATA;
                    } else {
@@ -1124,7 +1118,7 @@ describe("megolm-keys backup", () => {
                        };
                    }
                },
-                { overwriteRoutes: true },
+                { name: "room-keys" },
            );

            // Send Alice a message that she won't be able to decrypt, and check that she fetches the key from the backup.
@@ -1135,7 +1129,7 @@ describe("megolm-keys backup", () => {
            const event = room.getLiveTimeline().getEvents()[0];
            await advanceTimersUntil(awaitDecryption(event, { waitOnDecryptionFailure: true }));

-            expect(event.getContent()).toEqual(testData.CLEAR_EVENT.content);
+            expect(event.getContent<IContent>()).toEqual(testData.CLEAR_EVENT.content);

            // =====
            // Second suppose now that the backup has changed to version 2
@@ -1146,7 +1140,7 @@ describe("megolm-keys backup", () => {
                version: "2",
            };

-            fetchMock.get("path:/_matrix/client/v3/room_keys/version", newBackup, { overwriteRoutes: true });
+            fetchMock.modifyRoute("room-keys-version", { response: newBackup });
            // suppose the new key is now known
            const aliceCrypto = aliceClient.getCrypto()!;
            await aliceCrypto.storeSessionBackupPrivateKey(
@@ -1159,11 +1153,10 @@ describe("megolm-keys backup", () => {

            const awaitHasQueriedNewBackup: PromiseWithResolvers<void> = Promise.withResolvers<void>();

-            fetchMock.get(
-                "express:/_matrix/client/v3/room_keys/keys/:room_id/:session_id",
-                (url, request) => {
+            fetchMock.modifyRoute("room-keys", {
+                response: (callLog) => {
                    // check that the version is correct
-                    const version = new URLSearchParams(new URL(url).search).get("version");
+                    const version = new URLSearchParams(new URL(callLog.url).search).get("version");
                    if (version == newBackup.version) {
                        awaitHasQueriedNewBackup.resolve();
                        return testData.CURVE25519_KEY_BACKUP_DATA;
@@ -1179,8 +1172,7 @@ describe("megolm-keys backup", () => {
                        };
                    }
                },
-                { overwriteRoutes: true },
-            );
+            });

            // Send Alice a message that she won't be able to decrypt, and check that she fetches the key from the new backup.
            const newMessage: Partial<IEvent> = {
@@ -1216,7 +1208,7 @@ describe("megolm-keys backup", () => {
        // user will be one).
        syncResponder.sendOrQueueSyncResponse({});
        // DeviceList has a sleep(5) which we need to make happen
-        await jest.advanceTimersByTimeAsync(10);
+        await vi.advanceTimersByTimeAsync(10);

        // The client should now know about the dummy device
        const devices = await aliceClient.getCrypto()!.getUserDeviceInfo([TEST_USER_ID]);
@@ -16,6 +16,8 @@ limitations under the License.

 import Olm from "@matrix-org/olm";
 import anotherjson from "another-json";
+import fetchMock from "@fetch-mock/vitest";
+import { type RouteResponse } from "fetch-mock";

 import {
    type IContent,
@@ -30,6 +32,7 @@ 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";

 /**
 * @module
@@ -93,15 +96,15 @@ export function bootstrapCrossSigningTestOlmAccount(
    deviceId: string,
    keyBackupInfo: KeyBackupInfo[] = [],
 ): Partial<IDownloadKeyResult> {
-    const olmAliceMSK = new globalThis.Olm.PkSigning();
+    const olmAliceMSK = new Olm.PkSigning();
    const masterPrivkey = olmAliceMSK.generate_seed();
    const masterPubkey = olmAliceMSK.init_with_seed(masterPrivkey);

-    const olmAliceUSK = new globalThis.Olm.PkSigning();
+    const olmAliceUSK = new Olm.PkSigning();
    const userPrivkey = olmAliceUSK.generate_seed();
    const userPubkey = olmAliceUSK.init_with_seed(userPrivkey);

-    const olmAliceSSK = new globalThis.Olm.PkSigning();
+    const olmAliceSSK = new Olm.PkSigning();
    const sskPrivkey = olmAliceSSK.generate_seed();
    const sskPubkey = olmAliceSSK.init_with_seed(sskPrivkey);

@@ -189,7 +192,7 @@ export async function createOlmSession(
    const otkId = Object.keys(keys)[0];
    const otk = keys[otkId];

-    const session = new globalThis.Olm.Session();
+    const session = new Olm.Session();
    session.create_outbound(olmAccount, recipientTestClient.getDeviceKey(), otk.key);
    return session;
 }
@@ -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 +420,128 @@ 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/"), (callLog): RouteResponse => {
+            const content = JSON.parse(callLog.options.body as string);
+            resolve(onSendRoomKey(content));
+            return {};
+        });
+    });
+}
+
+/**
+ * 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/"), (callLog) => {
+            const content = JSON.parse(callLog.options.body as string);
+            resolve(content);
+            return { event_id: "$event_id" };
+        });
+    });
+}
+
+/**
+ * Return the event received on rooms/{roomId}/state/m.room.encrypted/{stateKey} endpoint.
+ * See https://spec.matrix.org/latest/client-server-api/#put_matrixclientv3roomsroomidstateeventtypestatekey
+ * @returns the content of the encrypted event
+ */
+function expectEncryptedSendStateEvent() {
+    return new Promise<IContent>((resolve) => {
+        fetchMock.putOnce(new RegExp("/state/m.room.encrypted/"), (callLog) => {
+            const content = JSON.parse(callLog.options.body as string);
+            resolve(content);
+            return { event_id: "$event_id" };
+        });
+    });
+}
+
+/**
+ * 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);
+}
@@ -16,7 +16,7 @@ limitations under the License.

 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { createClient, IndexedDBCryptoStore } from "../../../src";
 import { populateStore } from "../../test-utils/test_indexeddb_cryptostore_dump";
@@ -26,7 +26,7 @@ import { FULL_ACCOUNT_DATASET } from "../../test-utils/test_indexeddb_cryptostor
 import { EMPTY_ACCOUNT_DATASET } from "../../test-utils/test_indexeddb_cryptostore_dump/empty_account";
 import { CryptoEvent } from "../../../src/crypto-api";

-jest.setTimeout(15000);
+vi.setConfig({ testTimeout: 15000 });

 afterEach(() => {
    // reset fake-indexeddb after each test, to make sure we don't leak connections
@@ -122,6 +122,7 @@ describe("MatrixClient.initRustCrypto", () => {
        );
    });

+    // eslint-disable-next-line @vitest/expect-expect
    it("should ignore a second call", async () => {
        const matrixClient = createClient({
            baseUrl: "http://test.server",
@@ -134,10 +135,6 @@ describe("MatrixClient.initRustCrypto", () => {
    });

    describe("Libolm Migration", () => {
-        beforeEach(() => {
-            fetchMock.reset();
-        });
-
        it("should migrate from libolm", async () => {
            fetchMock.get("path:/_matrix/client/v3/room_keys/version", FULL_ACCOUNT_DATASET.backupResponse);

@@ -155,7 +152,7 @@ describe("MatrixClient.initRustCrypto", () => {
                pickleKey: FULL_ACCOUNT_DATASET.pickleKey,
            });

-            const progressListener = jest.fn();
+            const progressListener = vi.fn();
            matrixClient.addListener(CryptoEvent.LegacyCryptoStoreMigrationProgress, progressListener);

            await matrixClient.initRustCrypto();
@@ -326,7 +323,7 @@ describe("MatrixClient.initRustCrypto", () => {
            });

            // When we start Rust crypto, potentially triggering an upgrade
-            const progressListener = jest.fn();
+            const progressListener = vi.fn();
            matrixClient.addListener(CryptoEvent.LegacyCryptoStoreMigrationProgress, progressListener);

            await matrixClient.initRustCrypto();
@@ -478,6 +475,7 @@ describe("MatrixClient.clearStores", () => {
        expect(await indexedDB.databases()).toHaveLength(0);
    });

+    // eslint-disable-next-line @vitest/expect-expect
    it("should not fail in environments without indexedDB", async () => {
        // eslint-disable-next-line no-global-assign
        indexedDB = undefined!;
@@ -0,0 +1,221 @@
+/*
+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/vitest";
+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,
+    HistoryVisibility,
+    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);
+
+        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 () => {
+        aliceClient.stopClient();
+    });
+
+    function expectAliceKeyQuery(response: any) {
+        fetchMock.postOnce(new RegExp("/keys/query"), (callLog) => response);
+    }
+
+    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!");
+    });
+
+    // eslint-disable-next-line @vitest/expect-expect
+    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"], HistoryVisibility.Joined, 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),
+        ]);
+    });
+});
@@ -14,16 +14,25 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";
 import "fake-indexeddb/auto";
 import { IDBFactory } from "fake-indexeddb";
+import Olm from "@matrix-org/olm";

 import { getSyncResponse, syncPromise } from "../../test-utils/test-utils";
-import { createClient, type MatrixClient } from "../../../src";
+import {
+    ClientEvent,
+    createClient,
+    type IToDeviceEvent,
+    type MatrixClient,
+    type MatrixEvent,
+    type ReceivedToDeviceMessage,
+} from "../../../src";
 import * as testData from "../../test-utils/test-data";
 import { E2EKeyResponder } from "../../test-utils/E2EKeyResponder";
 import { SyncResponder } from "../../test-utils/SyncResponder";
 import { E2EKeyReceiver } from "../../test-utils/E2EKeyReceiver";
+import { encryptOlmEvent, establishOlmSession, getTestOlmAccountKeys } from "./olm-utils.ts";

 afterEach(() => {
    // reset fake-indexeddb after each test, to make sure we don't leak connections
@@ -43,12 +52,13 @@ describe("to-device-messages", () => {

    /** an object which intercepts `/keys/query` requests on the test homeserver */
    let e2eKeyResponder: E2EKeyResponder;
+    let e2eKeyReceiver: E2EKeyReceiver;
+    let syncResponder: SyncResponder;

    beforeEach(
        async () => {
            // anything that we don't have a specific matcher for silently returns a 404
            fetchMock.catch(404);
-            fetchMock.config.warnOnFallback = false;

            const homeserverUrl = "https://server.com";
            aliceClient = createClient({
@@ -59,8 +69,8 @@ describe("to-device-messages", () => {
            });

            e2eKeyResponder = new E2EKeyResponder(homeserverUrl);
-            new E2EKeyReceiver(homeserverUrl);
-            const syncResponder = new SyncResponder(homeserverUrl);
+            e2eKeyReceiver = new E2EKeyReceiver(homeserverUrl);
+            syncResponder = new SyncResponder(homeserverUrl);

            // add bob as known user
            syncResponder.sendOrQueueSyncResponse(getSyncResponse([testData.BOB_TEST_USER_ID]));
@@ -89,7 +99,6 @@ describe("to-device-messages", () => {

    afterEach(async () => {
        aliceClient.stopClient();
-        fetchMock.mockReset();
    });

    describe("encryptToDeviceMessages", () => {
@@ -149,4 +158,111 @@ describe("to-device-messages", () => {
            // for future: check that bob's device can decrypt the ciphertext?
        });
    });
+
+    describe("receive to-device-messages", () => {
+        it("Should receive decrypted to-device message via ClientEvent", async () => {
+            // create a test olm device which we will use to communicate with alice. We use libolm to implement this.
+            await Olm.init();
+            const testOlmAccount = new Olm.Account();
+            testOlmAccount.create();
+
+            const testDeviceKeys = getTestOlmAccountKeys(testOlmAccount, "@bob:xyz", "DEVICE_ID");
+            e2eKeyResponder.addDeviceKeys(testDeviceKeys);
+
+            await aliceClient.startClient();
+            await syncPromise(aliceClient);
+
+            syncResponder.sendOrQueueSyncResponse(getSyncResponse(["@bob:xyz"]));
+            await syncPromise(aliceClient);
+
+            const p2pSession = await establishOlmSession(aliceClient, e2eKeyReceiver, syncResponder, testOlmAccount);
+
+            const toDeviceEvent = encryptOlmEvent({
+                sender: "@bob:xyz",
+                senderKey: testDeviceKeys.keys[`curve25519:DEVICE_ID`],
+                senderSigningKey: testDeviceKeys.keys[`ed25519:DEVICE_ID`],
+                p2pSession: p2pSession,
+                recipient: aliceClient.getUserId()!,
+                recipientCurve25519Key: e2eKeyReceiver.getDeviceKey(),
+                recipientEd25519Key: e2eKeyReceiver.getSigningKey(),
+                plaincontent: {
+                    body: "foo",
+                },
+                plaintype: "m.test.type",
+            });
+
+            const processedToDeviceResolver: PromiseWithResolvers<ReceivedToDeviceMessage> = Promise.withResolvers();
+
+            aliceClient.on(ClientEvent.ReceivedToDeviceMessage, (payload) => {
+                processedToDeviceResolver.resolve(payload);
+            });
+
+            const oldToDeviceResolver: PromiseWithResolvers<MatrixEvent> = Promise.withResolvers();
+
+            aliceClient.on(ClientEvent.ToDeviceEvent, (event) => {
+                oldToDeviceResolver.resolve(event);
+            });
+
+            expect(toDeviceEvent.type).toBe("m.room.encrypted");
+
+            syncResponder.sendOrQueueSyncResponse({ to_device: { events: [toDeviceEvent] } });
+            await syncPromise(aliceClient);
+
+            const { message, encryptionInfo } = await processedToDeviceResolver.promise;
+
+            expect(message.type).toBe("m.test.type");
+            expect(message.content["body"]).toBe("foo");
+
+            expect(encryptionInfo).not.toBeNull();
+            expect(encryptionInfo!.senderVerified).toBe(false);
+            expect(encryptionInfo!.sender).toBe("@bob:xyz");
+            expect(encryptionInfo!.senderDevice).toBe("DEVICE_ID");
+
+            const oldFormat = await oldToDeviceResolver.promise;
+            expect(oldFormat.isEncrypted()).toBe(true);
+            expect(oldFormat.getType()).toBe("m.test.type");
+            expect(oldFormat.getContent()["body"]).toBe("foo");
+        });
+
+        it("Should receive clear to-device message via ClientEvent", async () => {
+            await aliceClient.startClient();
+            await syncPromise(aliceClient);
+
+            const toDeviceEvent: IToDeviceEvent = {
+                sender: "@bob:xyz",
+                type: "m.test.type",
+                content: {
+                    body: "foo",
+                },
+            };
+
+            const processedToDeviceResolver: PromiseWithResolvers<ReceivedToDeviceMessage> = Promise.withResolvers();
+
+            aliceClient.on(ClientEvent.ReceivedToDeviceMessage, (payload) => {
+                processedToDeviceResolver.resolve(payload);
+            });
+
+            const oldToDeviceResolver: PromiseWithResolvers<MatrixEvent> = Promise.withResolvers();
+
+            aliceClient.on(ClientEvent.ToDeviceEvent, (event) => {
+                oldToDeviceResolver.resolve(event);
+            });
+
+            syncResponder.sendOrQueueSyncResponse({ to_device: { events: [toDeviceEvent] } });
+            await syncPromise(aliceClient);
+
+            const { message, encryptionInfo } = await processedToDeviceResolver.promise;
+
+            expect(message.type).toBe("m.test.type");
+            expect(message.content["body"]).toBe("foo");
+
+            // When the message is not encrypted, we don't have the encryptionInfo.
+            expect(encryptionInfo).toBeNull();
+
+            const oldFormat = await oldToDeviceResolver.promise;
+            expect(oldFormat.isEncrypted()).toBe(false);
+            expect(oldFormat.getType()).toBe("m.test.type");
+            expect(oldFormat.getContent()["body"]).toBe("foo");
+        });
+    });
 });
@@ -17,14 +17,16 @@ limitations under the License.
 import "fake-indexeddb/auto";

 import anotherjson from "another-json";
-import fetchMock from "fetch-mock-jest";
+import debug from "debug";
+import fetchMock from "@fetch-mock/vitest";
+import { type RouteResponse } from "fetch-mock";
 import { IDBFactory } from "fake-indexeddb";
 import { createHash } from "crypto";
 import Olm from "@matrix-org/olm";

-import type FetchMock from "fetch-mock";
 import {
    createClient,
+    DebugLogger,
    DeviceVerification,
    type IContent,
    type ICreateClientOpts,
@@ -44,8 +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,
@@ -77,14 +79,9 @@ 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 globalThis.Olm.init();
+    await Olm.init();
 });

 // load the rust library. This can take a few seconds on a slow GH worker.
@@ -94,6 +91,10 @@ beforeAll(async () => {
    await RustSdkCryptoJs.initAsync();
 }, 10000);

+beforeEach(() => {
+    vi.useFakeTimers();
+});
+
 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
@@ -110,7 +111,6 @@ const TEST_HOMESERVER_URL = "https://alice-server.com";
 * These tests work by intercepting HTTP requests via fetch-mock rather than mocking out bits of the client, so as
 * to provide the most effective integration tests possible.
 */
-// we test with both crypto stacks...
 describe("verification", () => {
    /** the client under test */
    let aliceClient: MatrixClient;
@@ -127,7 +127,6 @@ describe("verification", () => {
    beforeEach(async () => {
        // anything that we don't have a specific matcher for silently returns a 404
        fetchMock.catch(404);
-        fetchMock.config.warnOnFallback = false;

        e2eKeyReceiver = new E2EKeyReceiver(TEST_HOMESERVER_URL);
        e2eKeyResponder = new E2EKeyResponder(TEST_HOMESERVER_URL);
@@ -138,14 +137,12 @@ describe("verification", () => {
    });

    afterEach(async () => {
-        if (aliceClient !== undefined) {
-            await aliceClient.stopClient();
-        }
+        aliceClient?.stopClient();

        // Allow in-flight things to complete before we tear down the test
-        await jest.runAllTimersAsync();
-
-        fetchMock.mockReset();
+        if (vi.isFakeTimers()) {
+            await vi.runAllTimersAsync();
+        }
    });

    describe("Outgoing verification requests for another device", () => {
@@ -153,11 +150,10 @@ describe("verification", () => {
            // pretend that we have another device, which we will verify
            e2eKeyResponder.addDeviceKeys(SIGNED_TEST_DEVICE_DATA);

-            fetchMock.put(
-                new RegExp(`/_matrix/client/(r0|v3)/sendToDevice/${escapeRegExp("m.secret.request")}`),
-                { ok: false, status: 404 },
-                { overwriteRoutes: true },
-            );
+            fetchMock.put(new RegExp(`/_matrix/client/(r0|v3)/sendToDevice/${escapeRegExp("m.secret.request")}`), {
+                ok: false,
+                status: 404,
+            });
        });

        // test with (1) the default verification method list, (2) a custom verification method list.
@@ -209,7 +205,7 @@ describe("verification", () => {
            expect(toDeviceMessage.from_device).toEqual(aliceClient.deviceId);
            expect(toDeviceMessage.transaction_id).toEqual(transactionId);
            if (methods !== undefined) {
-                // eslint-disable-next-line jest/no-conditional-expect
+                // eslint-disable-next-line @vitest/no-conditional-expect
                expect(new Set(toDeviceMessage.methods)).toEqual(new Set(methods));
            }

@@ -242,7 +238,7 @@ describe("verification", () => {
            const sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.accept");
            const verificationPromise = verifier.verify();
            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            jest.advanceTimersByTime(10);
+            vi.advanceTimersByTime(10);

            requestBody = await sendToDevicePromise;
            toDeviceMessage = requestBody.messages[TEST_USER_ID][TEST_DEVICE_ID];
@@ -254,7 +250,7 @@ describe("verification", () => {

            // The dummy device makes up a curve25519 keypair and sends the public bit back in an `m.key.verification.key'
            // We use the Curve25519, HMAC and HKDF implementations in libolm, for now
-            const olmSAS = new globalThis.Olm.SAS();
+            const olmSAS = new Olm.SAS();
            returnToDeviceMessageFromSync(buildSasKeyMessage(transactionId, olmSAS.get_pubkey()));

            // alice responds with a 'key' ...
@@ -320,7 +316,7 @@ describe("verification", () => {
            expect(request.otherPartySupportsMethod("m.sas.v1")).toBe(true);

            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            // And now Alice starts a SAS verification
            let sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.start");
@@ -348,7 +344,7 @@ describe("verification", () => {

            // The dummy device makes up a curve25519 keypair and uses the hash in an 'm.key.verification.accept'
            // We use the Curve25519, HMAC and HKDF implementations in libolm, for now
-            const olmSAS = new globalThis.Olm.SAS();
+            const olmSAS = new Olm.SAS();
            const commitmentStr = olmSAS.get_pubkey() + anotherjson.stringify(toDeviceMessage);

            sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.key");
@@ -513,7 +509,7 @@ describe("verification", () => {
            // Rust crypto waits for the 'done' to arrive from the other side.
            if (request.phase === VerificationPhase.Done) {
                const userVerificationStatus = await aliceClient.getCrypto()!.getUserVerificationStatus(TEST_USER_ID);
-                // eslint-disable-next-line jest/no-conditional-expect
+                // eslint-disable-next-line @vitest/no-conditional-expect
                expect(userVerificationStatus.isCrossSigningVerified()).toBeTruthy();
                await verificationPromise;
            }
@@ -636,7 +632,7 @@ describe("verification", () => {
            expect(request.verifier).toBeUndefined();

            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            // ... but Alice wants to do an SAS verification
            const sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.start");
@@ -681,7 +677,7 @@ describe("verification", () => {
            expect(request.verifier).toBeUndefined();

            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            // ... but the dummy device wants to do an SAS verification
            returnToDeviceMessageFromSync(buildSasStartMessage(transactionId));
@@ -734,6 +730,35 @@ 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([
@@ -760,7 +785,7 @@ describe("verification", () => {
            const sendToDevicePromise = expectSendToDeviceMessage("m.key.verification.accept");
            const verificationPromise = verifier.verify();
            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            jest.advanceTimersByTime(10);
+            vi.advanceTimersByTime(10);
            await sendToDevicePromise;

            // now we unceremoniously cancel. We expect the verificatationPromise to reject.
@@ -905,19 +930,16 @@ describe("verification", () => {
        function awaitRoomMessageRequest(): Promise<IContent> {
            return new Promise((resolve) => {
                // Case of unencrypted message of the new crypto
-                fetchMock.put(
-                    "express:/_matrix/client/v3/rooms/:roomId/send/m.room.message/:txId",
-                    (url: string, options: RequestInit) => {
-                        resolve(JSON.parse(options.body as string));
-                        return { event_id: "$YUwRidLecu:example.com" };
-                    },
-                );
+                fetchMock.put("express:/_matrix/client/v3/rooms/:roomId/send/m.room.message/:txId", (callLog) => {
+                    resolve(JSON.parse(callLog.options.body as string));
+                    return { event_id: "$YUwRidLecu:example.com" };
+                });

                // Case of encrypted message of the old crypto
                fetchMock.put(
                    "express:/_matrix/client/v3/rooms/:roomId/send/m.room.encrypted/:txId",
-                    async (url: string, options: RequestInit) => {
-                        const encryptedMessage = JSON.parse(options.body as string);
+                    async (callLog) => {
+                        const encryptedMessage = JSON.parse(callLog.options.body as string);
                        const event = new MatrixEvent({
                            content: encryptedMessage,
                            type: "m.room.encrypted",
@@ -940,7 +962,7 @@ describe("verification", () => {

            // In `DeviceList#doQueuedQueries`, the key download response is processed every 5ms
            // 5ms by users, ie Bob and Alice
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            const messageRequestPromise = awaitRoomMessageRequest();
            const verificationRequest = await aliceClient
@@ -1050,7 +1072,14 @@ describe("verification", () => {
        });

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

            const verificationRequestEvent = createVerificationRequestEvent();
@@ -1064,6 +1093,16 @@ 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.
+            vi.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(
@@ -1071,6 +1110,29 @@ 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());
@@ -1115,7 +1177,7 @@ describe("verification", () => {
            returnToDeviceMessageFromSync(toDeviceEvent);

            // advance the clock, because the devicelist likes to sleep for 5ms during key downloads
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            // Wait for the request to be decrypted
            const request1 = await requestEventPromise;
@@ -1152,7 +1214,7 @@ describe("verification", () => {
            expect(matrixEvent.getContent().msgtype).toEqual("m.bad.encrypted");

            // Advance time by 5mins, the verification request should be ignored after that
-            jest.advanceTimersByTime(5 * 60 * 1000);
+            vi.advanceTimersByTime(5 * 60 * 1000);

            // Send Bob the room keys
            returnToDeviceMessageFromSync(toDeviceEvent);
@@ -1218,7 +1280,7 @@ describe("verification", () => {
            syncResponder.sendOrQueueSyncResponse(getSyncResponse([TEST_USER_ID]));
            await syncPromise(aliceClient);
            // DeviceList has a sleep(5) which we need to make happen
-            await jest.advanceTimersByTimeAsync(10);
+            await vi.advanceTimersByTimeAsync(10);

            // The client should now know about the olm device
            const devices = await aliceClient.getCrypto()!.getUserDeviceInfo([TEST_USER_ID]);
@@ -1230,11 +1292,10 @@ describe("verification", () => {
            testOlmAccount?.free();

            // Allow in-flight things to complete before we tear down the test
-            await jest.runAllTimersAsync();
-
-            fetchMock.mockReset();
+            await vi.runAllTimersAsync();
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("Should request cross signing keys after verification", async () => {
            const requestPromises = mockSecretRequestAndGetPromises();

@@ -1352,11 +1413,11 @@ describe("verification", () => {
         */
        async function retrieveBackupPrivateKeyWithDelay(): Promise<Uint8Array | null> {
            // We are lacking a way to signal that the secret has been received, so we wait a bit..
-            jest.useRealTimers();
+            vi.useRealTimers();
            await new Promise((resolve) => {
                setTimeout(resolve, 500);
            });
-            jest.useFakeTimers({ doNotFake: ["queueMicrotask"] });
+            vi.useFakeTimers();

            return aliceClient.getCrypto()!.getSessionBackupPrivateKey();
        }
@@ -1389,27 +1450,21 @@ describe("verification", () => {
            });

            const expectBackupCheck = new Promise((resolve) => {
-                fetchMock.get(
-                    "express:/_matrix/client/v3/room_keys/version",
-                    (url, request) => {
-                        resolve(undefined);
-                        if (expectBackup instanceof MatrixError) {
-                            return {
-                                status: expectBackup.httpStatus,
-                                body: expectBackup.data,
-                            };
-                        }
+                fetchMock.get("express:/_matrix/client/v3/room_keys/version", (callLog) => {
+                    resolve(undefined);
+                    if (expectBackup instanceof MatrixError) {
+                        return {
+                            status: expectBackup.httpStatus,
+                            body: expectBackup.data,
+                        };
+                    }

-                        if (expectBackup instanceof Error) {
-                            return Promise.reject(expectBackup);
-                        }
+                    if (expectBackup instanceof Error) {
+                        return Promise.reject(expectBackup);
+                    }

-                        return expectBackup;
-                    },
-                    {
-                        overwriteRoutes: true,
-                    },
-                );
+                    return expectBackup;
+                });
            });

            fetchMock.get("express:/_matrix/client/v3/room_keys/keys", CURVE25519_KEY_BACKUP_DATA);
@@ -1476,6 +1531,7 @@ describe("verification", () => {
            userId: TEST_USER_ID,
            accessToken: "akjgkrgjs",
            deviceId: "device_under_test",
+            logger: new DebugLogger(debug(`matrix-js-sdk:verification`)),
            ...opts,
        });
        await client.initRustCrypto();
@@ -1489,7 +1545,7 @@ describe("verification", () => {
        // user will be one).
        syncResponder.sendOrQueueSyncResponse({});
        // DeviceList has a sleep(5) which we need to make happen
-        await jest.advanceTimersByTimeAsync(10);
+        await vi.advanceTimersByTimeAsync(10);

        // The client should now know about the dummy device
        const devices = await aliceClient.getCrypto()!.getUserDeviceInfo([TEST_USER_ID]);
@@ -1523,8 +1579,8 @@ function expectSendToDeviceMessage(msgtype: string): Promise<{ messages: any }>
    return new Promise((resolve) => {
        fetchMock.putOnce(
            new RegExp(`/_matrix/client/(r0|v3)/sendToDevice/${escapeRegExp(msgtype)}`),
-            (url: string, opts: RequestInit): FetchMock.MockResponse => {
-                resolve(JSON.parse(opts.body as string));
+            (callLog): RouteResponse => {
+                resolve(JSON.parse(callLog.options.body as string));
                return {};
            },
        );
@@ -1545,29 +1601,25 @@ function mockSecretRequestAndGetPromises(): Map<string, Promise<string>> {
    const uskRequestResolvers = Promise.withResolvers<string>();
    const backupKeyRequestResolvers = Promise.withResolvers<string>();

-    fetchMock.put(
-        new RegExp(`/_matrix/client/(r0|v3)/sendToDevice/m.secret.request`),
-        (url: string, opts: RequestInit): FetchMock.MockResponse => {
-            const messages = JSON.parse(opts.body as string).messages[TEST_USER_ID];
-            // rust crypto broadcasts to all devices, old crypto to a specific device, take the first one
-            const content = Object.values(messages)[0] as any;
-            if (content.action == "request") {
-                const name = content.name;
-                const requestId = content.request_id;
-                if (name == "m.cross_signing.user_signing") {
-                    uskRequestResolvers.resolve(requestId);
-                } else if (name == "m.cross_signing.master") {
-                    mskRequestResolvers.resolve(requestId);
-                } else if (name == "m.cross_signing.self_signing") {
-                    sskRequestResolvers.resolve(requestId);
-                } else if (name == "m.megolm_backup.v1") {
-                    backupKeyRequestResolvers.resolve(requestId);
-                }
+    fetchMock.put(new RegExp(`/_matrix/client/(r0|v3)/sendToDevice/m.secret.request`), (callLog): RouteResponse => {
+        const messages = JSON.parse(callLog.options.body as string).messages[TEST_USER_ID];
+        // rust crypto broadcasts to all devices, old crypto to a specific device, take the first one
+        const content = Object.values(messages)[0] as any;
+        if (content.action == "request") {
+            const name = content.name;
+            const requestId = content.request_id;
+            if (name == "m.cross_signing.user_signing") {
+                uskRequestResolvers.resolve(requestId);
+            } else if (name == "m.cross_signing.master") {
+                mskRequestResolvers.resolve(requestId);
+            } else if (name == "m.cross_signing.self_signing") {
+                sskRequestResolvers.resolve(requestId);
+            } else if (name == "m.megolm_backup.v1") {
+                backupKeyRequestResolvers.resolve(requestId);
            }
-            return {};
-        },
-        { overwriteRoutes: true },
-    );
+        }
+        return {};
+    });

    const promiseMap = new Map<string, Promise<string>>();
    promiseMap.set("m.cross_signing.master", mskRequestResolvers.promise);
@@ -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(),
            ]);
        });
@@ -2044,6 +2044,7 @@ describe("MatrixClient event timelines", function () {
            expect(timeline!.getEvents()[1]!.event).toEqual(THREAD_REPLY);
        }

+        // eslint-disable-next-line @vitest/expect-expect
        it("in stable mode", async () => {
            // @ts-ignore
            client.clientOpts.threadSupport = true;
@@ -267,6 +267,59 @@ describe("MatrixClient", function () {
        });
    });

+    describe("invite", function () {
+        it("should send request to /invite", async () => {
+            const roomId = "!roomId:server";
+            const userId = "@user:server";
+
+            httpBackend
+                .when("POST", `/rooms/${encodeURIComponent(roomId)}/invite`)
+                .check((request) => {
+                    expect(request.data).toEqual({ user_id: userId });
+                })
+                .respond(200, {});
+
+            const prom = client.invite(roomId, userId);
+            await httpBackend.flushAllExpected();
+            await prom;
+            httpBackend.verifyNoOutstandingExpectation();
+        });
+
+        it("accepts a stringy reason argument", async () => {
+            const roomId = "!roomId:server";
+            const userId = "@user:server";
+
+            httpBackend
+                .when("POST", `/rooms/${encodeURIComponent(roomId)}/invite`)
+                .check((request) => {
+                    expect(request.data).toEqual({ user_id: userId, reason: "testreason" });
+                })
+                .respond(200, {});
+
+            const prom = client.invite(roomId, userId, "testreason");
+            await httpBackend.flushAllExpected();
+            await prom;
+            httpBackend.verifyNoOutstandingExpectation();
+        });
+
+        it("accepts an options object with a reason", async () => {
+            const roomId = "!roomId:server";
+            const userId = "@user:server";
+
+            httpBackend
+                .when("POST", `/rooms/${encodeURIComponent(roomId)}/invite`)
+                .check((request) => {
+                    expect(request.data).toEqual({ user_id: userId, reason: "testreason" });
+                })
+                .respond(200, {});
+
+            const prom = client.invite(roomId, userId, { reason: "testreason" });
+            await httpBackend.flushAllExpected();
+            await prom;
+            httpBackend.verifyNoOutstandingExpectation();
+        });
+    });
+
    describe("knockRoom", function () {
        const roomId = "!some-room-id:example.org";
        const reason = "some reason";
@@ -294,6 +347,7 @@ describe("MatrixClient", function () {
            expect((await prom).room_id).toBe(roomId);
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("should no-op if you've already knocked a room", function () {
            const room = new Room(roomId, client, userId);

@@ -327,23 +381,16 @@ describe("MatrixClient", function () {
                [
                    403,
                    { errcode: "M_FORBIDDEN", error: "You don't have permission to knock" },
-                    "[M_FORBIDDEN: MatrixError: [403] You don't have permission to knock]",
-                ],
-                [
-                    500,
-                    { errcode: "INTERNAL_SERVER_ERROR" },
-                    "[INTERNAL_SERVER_ERROR: MatrixError: [500] Unknown message]",
+                    "MatrixError: [403] You don't have permission to knock",
                ],
+                [500, { errcode: "INTERNAL_SERVER_ERROR" }, "MatrixError: [500] Unknown message"],
            ];

            it.each(testCases)("should handle %s error", async (code, { errcode, error }, snapshot) => {
                httpBackend.when("POST", "/knock/" + encodeURIComponent(roomId)).respond(code, { errcode, error });

                const prom = client.knockRoom(roomId);
-                await Promise.all([
-                    httpBackend.flushAllExpected(),
-                    expect(prom).rejects.toMatchInlineSnapshot(snapshot),
-                ]);
+                await Promise.all([httpBackend.flushAllExpected(), expect(prom).rejects.toThrow(snapshot)]);
            });
        });
    });
@@ -1145,7 +1192,7 @@ describe("MatrixClient", function () {
    describe("logout", () => {
        it("should abort pending requests when called with stopClient=true", async () => {
            httpBackend.when("POST", "/logout").respond(200, {});
-            const fn = jest.fn();
+            const fn = vi.fn();
            client.http.request(Method.Get, "/test").catch(fn);
            client.logout(true);
            await httpBackend.flush(undefined);
@@ -1273,7 +1320,7 @@ describe("MatrixClient", function () {
        });

        afterEach(() => {
-            jest.useRealTimers();
+            vi.useRealTimers();
        });

        it("should always fetch capabilities and then cache", async () => {
@@ -1344,6 +1391,7 @@ describe("MatrixClient", function () {
    });

    describe("publicRooms", () => {
+        // eslint-disable-next-line @vitest/expect-expect
        it("should use GET request if no server or filter is specified", () => {
            httpBackend.when("GET", "/publicRooms").respond(200, {});
            client.publicRooms({});
@@ -1532,7 +1580,7 @@ describe("MatrixClient", function () {

    describe("setSyncPresence", () => {
        it("should pass calls through to the underlying sync api", () => {
-            const setPresence = jest.fn();
+            const setPresence = vi.fn();
            // @ts-ignore
            client.syncApi = { setPresence };
            client.setSyncPresence(SetPresence.Unavailable);
@@ -1541,6 +1589,7 @@ describe("MatrixClient", function () {
    });

    describe("sendTyping", () => {
+        // eslint-disable-next-line @vitest/expect-expect
        it("should bail early for guests", async () => {
            client.setGuest(true);
            await client.sendTyping("!room:server", true, 100);
@@ -1798,6 +1847,7 @@ describe("MatrixClient", function () {
    });

    describe("setRoomMutePushRule", () => {
+        // eslint-disable-next-line @vitest/expect-expect
        it("should set room push rule to muted", async () => {
            const roomId = "!roomId:server";
            const client = new MatrixClient({
@@ -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 () => {
@@ -720,7 +720,7 @@ describe("MatrixClient room timelines", function () {
                    } else {
                        reject(new Error("TestError: Timed out while waiting for `RoomEvent.TimelineReset` to fire."));
                    }
-                }, 4000 /* FIXME: Is there a way to reference the current timeout of this test in Jest? */);
+                }, 4000 /* FIXME: Is there a way to reference the current timeout of this test in Vitest? */);

                room.on(RoomEvent.TimelineReset, async () => {
                    try {
@@ -15,7 +15,7 @@ limitations under the License.
 */

 import "fake-indexeddb/auto";
-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { type MatrixClient, ClientEvent, createClient, SyncState } from "../../src";

@@ -83,8 +83,7 @@ describe("MatrixClient syncing errors", () => {
    });

    it("should retry, until errors are solved.", async () => {
-        jest.useFakeTimers();
-        fetchMock.config.overwriteRoutes = false;
+        vi.useFakeTimers();
        fetchMock
            .getOnce("end:versions", {}) // first version check without credentials needs to succeed
            .getOnce("end:versions", 429) // second version check fails with 429 triggering another retry
@@ -105,19 +104,18 @@ describe("MatrixClient syncing errors", () => {

        await client!.startClient();
        expect(await syncEvents[0].promise).toBe(SyncState.Error);
-        jest.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
+        vi.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
        expect(await syncEvents[1].promise).toBe(SyncState.Error);
-        jest.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
+        vi.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
        expect(await syncEvents[2].promise).toBe(SyncState.Prepared);
-        jest.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
+        vi.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
        expect(await syncEvents[3].promise).toBe(SyncState.Syncing);
-        jest.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
+        vi.advanceTimersByTime(60 * 1000); // this will skip forward to trigger the keepAlive/sync
        expect(await syncEvents[4].promise).toBe(SyncState.Syncing);
    });

    it("should stop sync keep alive when client is stopped.", async () => {
-        jest.useFakeTimers();
-        fetchMock.config.overwriteRoutes = false;
+        vi.useFakeTimers();
        fetchMock
            .get("end:capabilities", {})
            .getOnce("end:versions", {}) // first version check without credentials needs to succeed
@@ -146,9 +144,9 @@ describe("MatrixClient syncing errors", () => {

        const syntState = await firstSyncEvent.promise;
        expect(syntState).toBe(SyncState.Error);
-        jest.runAllTimers(); // this will skip forward to trigger the keepAlive
+        vi.runAllTimers(); // this will skip forward to trigger the keepAlive

-        jest.useRealTimers(); // we need real timer for the setTimout below to work
+        vi.useRealTimers(); // we need real timer for the setTimout below to work

        const timeoutPromise = makeQueryablePromise(new Promise<void>((res) => setTimeout(res, 1)));

@@ -94,6 +94,7 @@ describe("MatrixClient syncing", () => {
            presence: {},
        };

+        // eslint-disable-next-line @vitest/expect-expect
        it("should /sync after /pushrules and /filter.", async () => {
            httpBackend!.when("GET", "/sync").respond(200, syncData);

@@ -501,7 +502,7 @@ describe("MatrixClient syncing", () => {
                })
                .respond(200, syncData);

-            client!.store.getSavedSyncToken = jest.fn().mockResolvedValue("this-is-a-token");
+            client!.store.getSavedSyncToken = vi.fn().mockResolvedValue("this-is-a-token");
            client!.startClient({ initialSyncLimit: 1 });

            return httpBackend!.flushAllExpected();
@@ -994,7 +995,7 @@ describe("MatrixClient syncing", () => {
                    roomVersion: "org.matrix.msc2716v3",
                },
            ].forEach((testMeta) => {
-                // eslint-disable-next-line jest/valid-title
+                // eslint-disable-next-line @vitest/valid-title
                describe(testMeta.label, () => {
                    const roomCreateEvent = utils.mkEvent({
                        type: "m.room.create",
@@ -1835,7 +1836,7 @@ describe("MatrixClient syncing", () => {
            await Promise.all([httpBackend!.flushAllExpected(), awaitSyncEvent()]);

            const room = client!.getRoom(roomOne);
-            room!.hasEncryptionStateEvent = jest.fn().mockReturnValue(true);
+            room!.hasEncryptionStateEvent = vi.fn().mockReturnValue(true);

            expect(room!.getThreadUnreadNotificationCount(THREAD_ID, NotificationCountType.Total)).toBe(5);

@@ -2519,7 +2520,7 @@ describe("MatrixClient syncing", () => {
            const eventB2 = new MatrixEvent({ type: "b", content: { body: "2" } });

            client!.store.storeAccountDataEvents([eventA1, eventB1]);
-            const fn = jest.fn();
+            const fn = vi.fn();
            client!.on(ClientEvent.AccountData, fn);

            httpBackend!.when("GET", "/sync").respond(200, {
@@ -62,7 +62,7 @@ describe("Notification count fixing", () => {

        client!.startClient({ threadSupport: true });
        const room = new Room(roomId, client!, selfUserId);
-        jest.spyOn(client!, "getRoom").mockImplementation((id) => (id === roomId ? room : null));
+        vi.spyOn(client!, "getRoom").mockImplementation((id) => (id === roomId ? room : null));

        const event = new MatrixEvent({
            room_id: roomId,
@@ -77,7 +77,7 @@ describe("Notification count fixing", () => {
            },
        });

-        jest.spyOn(event, "getPushActions").mockReturnValue({
+        vi.spyOn(event, "getPushActions").mockReturnValue({
            notify: true,
            tweaks: {},
        });
@@ -123,7 +123,7 @@ describe("MatrixClient syncing", () => {
        ]);

        const room = new Room(roomId, client!, selfUserId);
-        jest.spyOn(client!, "getRoom").mockImplementation((id) => (id === roomId ? room : null));
+        vi.spyOn(client!, "getRoom").mockImplementation((id) => (id === roomId ? room : null));

        const thread = mkThread({ room, client: client!, authorId: selfUserId, participantUserIds: [selfUserId] });
        const threadReply = thread.events.at(-1)!;
@@ -143,7 +143,7 @@ describe("MatrixClient syncing", () => {

        const reactionEventId = `$9-${Math.random()}-${Math.random()}`;
        let lastEvent: MatrixEvent | null = null;
-        jest.spyOn(client! as any, "sendEventHttpRequest").mockImplementation((event) => {
+        vi.spyOn(client! as any, "sendEventHttpRequest").mockImplementation((event) => {
            lastEvent = event as MatrixEvent;
            return { event_id: reactionEventId };
        });
@@ -195,7 +195,7 @@ describe("MatrixClient syncing", () => {
                })
                .respond(200, syncData);

-            client!.store.getSavedSyncToken = jest.fn().mockResolvedValue("this-is-a-token");
+            client!.store.getSavedSyncToken = vi.fn().mockResolvedValue("this-is-a-token");
            client!.startClient({ initialSyncLimit: 1 });

            await httpBackend!.flushAllExpected();
@@ -14,9 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { QrCodeData, QrCodeMode } from "@matrix-org/matrix-sdk-crypto-wasm";
-import { mocked } from "jest-mock";
-import fetchMock from "fetch-mock-jest";
+import { QrCodeData, QrCodeIntent } from "@matrix-org/matrix-sdk-crypto-wasm";
+import fetchMock from "@fetch-mock/vitest";

 import {
    MSC4108FailureReason,
@@ -40,7 +39,7 @@ import { makeDelegatedAuthConfig } from "../../test-utils/oidc";
 function makeMockClient(opts: { userId: string; deviceId: string; msc4108Enabled: boolean }): MatrixClient {
    const baseUrl = "https://example.com";
    const crypto = {
-        exportSecretsForQrLogin: jest.fn(),
+        exportSecretsForQrLogin: vi.fn(),
    };
    const client = {
        doesServerSupportUnstableFeature(feature: string) {
@@ -54,9 +53,9 @@ function makeMockClient(opts: { userId: string; deviceId: string; msc4108Enabled
        },
        baseUrl,
        getDomain: () => "example.com",
-        getDevice: jest.fn(),
-        getCrypto: jest.fn(() => crypto),
-        getAuthMetadata: jest.fn().mockResolvedValue(makeDelegatedAuthConfig("https://issuer/", [DEVICE_CODE_SCOPE])),
+        getDevice: vi.fn(),
+        getCrypto: vi.fn(() => crypto),
+        getAuthMetadata: vi.fn().mockResolvedValue(makeDelegatedAuthConfig("https://issuer/", [DEVICE_CODE_SCOPE])),
    } as unknown as MatrixClient;
    client.http = new MatrixHttpApi<IHttpOpts & { onlyData: true }>(client, {
        baseUrl: client.baseUrl,
@@ -77,10 +76,6 @@ describe("MSC4108SignInWithQR", () => {
        });
    });

-    afterEach(() => {
-        fetchMock.reset();
-    });
-
    const url = "https://fallbackserver/rz/123";
    const deviceId = "DEADB33F";
    const verificationUri = "https://example.com/verify";
@@ -115,10 +110,10 @@ describe("MSC4108SignInWithQR", () => {
            let opponentData = Promise.withResolvers<string>();

            const ourMockSession = {
-                send: jest.fn(async (newData) => {
+                send: vi.fn(async (newData) => {
                    ourData.resolve(newData);
                }),
-                receive: jest.fn(() => {
+                receive: vi.fn(() => {
                    const prom = opponentData.promise;
                    prom.then(() => {
                        opponentData = Promise.withResolvers();
@@ -134,10 +129,10 @@ describe("MSC4108SignInWithQR", () => {
                },
            } as unknown as MSC4108RendezvousSession;
            const opponentMockSession = {
-                send: jest.fn(async (newData) => {
+                send: vi.fn(async (newData) => {
                    opponentData.resolve(newData);
                }),
-                receive: jest.fn(() => {
+                receive: vi.fn(() => {
                    const prom = ourData.promise;
                    prom.then(() => {
                        ourData = Promise.withResolvers();
@@ -151,7 +146,7 @@ describe("MSC4108SignInWithQR", () => {

            const ourChannel = new MSC4108SecureChannel(ourMockSession);
            const qrCodeData = QrCodeData.fromBytes(
-                await ourChannel.generateCode(QrCodeMode.Reciprocate, client.getDomain()!),
+                await ourChannel.generateCode(QrCodeIntent.Reciprocate, client.getDomain()!),
            );
            const opponentChannel = new MSC4108SecureChannel(opponentMockSession, qrCodeData.publicKey);

@@ -171,7 +166,7 @@ describe("MSC4108SignInWithQR", () => {
        it("should be able to connect with opponent and share verificationUri", async () => {
            await Promise.all([ourLogin.negotiateProtocols(), opponentLogin.negotiateProtocols()]);

-            mocked(client.getDevice).mockRejectedValue(new MatrixError({ errcode: "M_NOT_FOUND" }, 404));
+            vi.mocked(client.getDevice).mockRejectedValue(new MatrixError({ errcode: "M_NOT_FOUND" }, 404));

            await Promise.all([
                expect(ourLogin.deviceAuthorizationGrant()).resolves.toEqual({
@@ -194,7 +189,7 @@ describe("MSC4108SignInWithQR", () => {
        it("should abort if device already exists", async () => {
            await Promise.all([ourLogin.negotiateProtocols(), opponentLogin.negotiateProtocols()]);

-            mocked(client.getDevice).mockResolvedValue({} as IMyDevice);
+            vi.mocked(client.getDevice).mockResolvedValue({} as IMyDevice);

            await Promise.all([
                expect(ourLogin.deviceAuthorizationGrant()).rejects.toThrow("Specified device ID already exists"),
@@ -244,12 +239,12 @@ describe("MSC4108SignInWithQR", () => {
            // @ts-ignore
            await opponentLogin.receive();

-            mocked(client.getDevice).mockResolvedValue({} as IMyDevice);
+            vi.mocked(client.getDevice).mockResolvedValue({} as IMyDevice);

            const secrets = {
                cross_signing: { master_key: "mk", user_signing_key: "usk", self_signing_key: "ssk" },
            };
-            client.getCrypto()!.exportSecretsBundle = jest.fn().mockResolvedValue(secrets);
+            client.getCrypto()!.exportSecretsBundle = vi.fn().mockResolvedValue(secrets);

            const payload = {
                secrets: expect.objectContaining(secrets),
@@ -261,13 +256,13 @@ describe("MSC4108SignInWithQR", () => {
        });

        it("should abort if device doesn't come up by timeout", async () => {
-            jest.spyOn(globalThis, "setTimeout").mockImplementation((fn) => {
+            vi.spyOn(globalThis, "setTimeout").mockImplementation((fn) => {
                fn();
                // TODO: mock timers properly
                return -1 as any;
            });
-            jest.spyOn(Date, "now").mockImplementation(() => {
-                return 12345678 + mocked(setTimeout).mock.calls.length * 1000;
+            vi.spyOn(Date, "now").mockImplementation(() => {
+                return 12345678 + vi.mocked(setTimeout).mock.calls.length * 1000;
            });

            await Promise.all([ourLogin.negotiateProtocols(), opponentLogin.negotiateProtocols()]);
@@ -280,7 +275,7 @@ describe("MSC4108SignInWithQR", () => {
            await opponentLogin.send({
                type: PayloadType.Success,
            });
-            mocked(client.getDevice).mockRejectedValue(new MatrixError({ errcode: "M_NOT_FOUND" }, 404));
+            vi.mocked(client.getDevice).mockRejectedValue(new MatrixError({ errcode: "M_NOT_FOUND" }, 404));

            const ourProm = ourLogin.shareSecrets();
            await expect(ourProm).rejects.toThrow("New device not found");
@@ -297,7 +292,7 @@ describe("MSC4108SignInWithQR", () => {
            await opponentLogin.send({
                type: PayloadType.Success,
            });
-            mocked(client.getDevice).mockRejectedValue(
+            vi.mocked(client.getDevice).mockRejectedValue(
                new MatrixError({ errcode: "M_UNKNOWN", error: "The message" }, 500),
            );

@@ -314,7 +309,7 @@ describe("MSC4108SignInWithQR", () => {
        });

        it("should not send secrets if user cancels", async () => {
-            jest.spyOn(globalThis, "setTimeout").mockImplementation((fn) => {
+            vi.spyOn(globalThis, "setTimeout").mockImplementation((fn) => {
                fn();
                // TODO: mock timers properly
                return -1 as any;
@@ -334,7 +329,7 @@ describe("MSC4108SignInWithQR", () => {
            await opponentLogin.receive();

            const deviceResolvers = Promise.withResolvers<IMyDevice>();
-            mocked(client.getDevice).mockReturnValue(deviceResolvers.promise);
+            vi.mocked(client.getDevice).mockReturnValue(deviceResolvers.promise);

            ourLogin.cancel(MSC4108FailureReason.UserCancelled).catch(() => {});
            deviceResolvers.resolve({} as IMyDevice);
@@ -342,7 +337,7 @@ describe("MSC4108SignInWithQR", () => {
            const secrets = {
                cross_signing: { master_key: "mk", user_signing_key: "usk", self_signing_key: "ssk" },
            };
-            client.getCrypto()!.exportSecretsBundle = jest.fn().mockResolvedValue(secrets);
+            client.getCrypto()!.exportSecretsBundle = vi.fn().mockResolvedValue(secrets);

            await Promise.all([
                expect(ourProm).rejects.toThrow("User cancelled"),
@@ -26,7 +26,7 @@ import {
    type Extension,
 } from "../../src/sliding-sync";
 import { TestClient } from "../TestClient";
-import { type IRoomEvent, type IStateEvent } from "../../src";
+import { type IContent, type IRoomEvent, type IStateEvent } from "../../src";
 import {
    type MatrixClient,
    type MatrixEvent,
@@ -68,17 +68,17 @@ describe("SlidingSyncSdk", () => {
    const selfAccessToken = "aseukfgwef";

    const mockifySlidingSync = (s: SlidingSync): SlidingSync => {
-        s.getListParams = jest.fn();
-        s.getListData = jest.fn();
-        s.getRoomSubscriptions = jest.fn();
-        s.modifyRoomSubscriptionInfo = jest.fn();
-        s.modifyRoomSubscriptions = jest.fn();
-        s.registerExtension = jest.fn();
-        s.setList = jest.fn();
-        s.setListRanges = jest.fn();
-        s.start = jest.fn();
-        s.stop = jest.fn();
-        s.resend = jest.fn();
+        s.getListParams = vi.fn();
+        s.getListData = vi.fn();
+        s.getRoomSubscriptions = vi.fn();
+        s.modifyRoomSubscriptionInfo = vi.fn();
+        s.modifyRoomSubscriptions = vi.fn();
+        s.registerExtension = vi.fn();
+        s.setList = vi.fn();
+        s.setListRanges = vi.fn();
+        s.start = vi.fn();
+        s.stop = vi.fn();
+        s.resend = vi.fn();
        return s;
    };

@@ -111,7 +111,7 @@ describe("SlidingSyncSdk", () => {
            expect(m.getType()).toEqual(want[i].type);
            expect(m.getSender()).toEqual(want[i].sender);
            expect(m.getId()).toEqual(want[i].event_id);
-            expect(m.getContent()).toEqual(want[i].content);
+            expect(m.getContent<IContent>()).toEqual(want[i].content);
            expect(m.getTs()).toEqual(want[i].origin_server_ts);
            if (want[i].unsigned) {
                expect(m.getUnsigned()).toEqual(want[i].unsigned);
@@ -126,7 +126,7 @@ describe("SlidingSyncSdk", () => {
    // assign client/httpBackend globals
    const setupClient = async (testOpts?: Partial<IStoredClientOpts & { withCrypto: boolean }>) => {
        testOpts = testOpts || {};
-        const syncOpts: SyncApiOptions = {};
+        const syncOpts: SyncApiOptions = { logger };
        const testClient = new TestClient(selfUserId, "DEVICE", selfAccessToken);
        httpBackend = testClient.httpBackend;
        client = testClient.client;
@@ -150,7 +150,7 @@ describe("SlidingSyncSdk", () => {
    // find an extension on a SlidingSyncSdk instance
    const findExtension = (name: string): Extension<any, any> => {
        expect(mockSlidingSync!.registerExtension).toHaveBeenCalled();
-        const mockFn = mockSlidingSync!.registerExtension as jest.Mock;
+        const mockFn = vi.mocked(mockSlidingSync!.registerExtension);
        // find the extension
        for (let i = 0; i < mockFn.mock.calls.length; i++) {
            const calledExtension = mockFn.mock.calls[i][0] as Extension<any, any>;
@@ -658,7 +658,7 @@ describe("SlidingSyncSdk", () => {
        });

        it("can update device lists", () => {
-            syncCryptoCallback!.processDeviceLists = jest.fn();
+            syncCryptoCallback!.processDeviceLists = vi.fn();
            ext.onResponse({
                device_lists: {
                    changed: ["@alice:localhost"],
@@ -672,7 +672,7 @@ describe("SlidingSyncSdk", () => {
        });

        it("can update OTK counts and unused fallback keys", () => {
-            syncCryptoCallback!.processKeyCounts = jest.fn();
+            syncCryptoCallback!.processKeyCounts = vi.fn();
            ext.onResponse({
                device_one_time_keys_count: {
                    signed_curve25519: 42,
@@ -722,7 +722,7 @@ describe("SlidingSyncSdk", () => {
            });
            globalData = client!.getAccountData(globalType)!;
            expect(globalData).toBeTruthy();
-            expect(globalData.getContent()).toEqual(globalContent);
+            expect(globalData.getContent<IContent>()).toEqual(globalContent);
        });

        it("processes rooms account data", async () => {
@@ -757,7 +757,7 @@ describe("SlidingSyncSdk", () => {
            expect(room).toBeTruthy();
            const event = room.getAccountData(roomType)!;
            expect(event).toBeTruthy();
-            expect(event.getContent()).toEqual(roomContent);
+            expect(event.getContent<IContent>()).toEqual(roomContent);
        });

        it("doesn't crash for unknown room account data", async () => {
@@ -847,6 +847,7 @@ describe("SlidingSyncSdk", () => {
            });
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("can handle missing fields", async () => {
            ext.onResponse({
                next_batch: "23456",
@@ -861,7 +862,7 @@ describe("SlidingSyncSdk", () => {
            };
            let called = false;
            client!.once(ClientEvent.ToDeviceEvent, (ev) => {
-                expect(ev.getContent()).toEqual(toDeviceContent);
+                expect(ev.getContent<IContent>()).toEqual(toDeviceContent);
                expect(ev.getType()).toEqual(toDeviceType);
                called = true;
            });
@@ -1095,6 +1096,7 @@ describe("SlidingSyncSdk", () => {
            expect(receipt?.data.thread_id).toBeFalsy();
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("gracefully handles missing rooms when receiving receipts", async () => {
            const roomId = "!room:id";
            const alice = "@alice:alice";
@@ -82,6 +82,7 @@ describe("SlidingSync", () => {
            await p;
        });

+        // eslint-disable-next-line @vitest/expect-expect
        it("should stop the sync loop upon calling stop()", () => {
            slidingSync.stop();
            httpBackend!.verifyNoOutstandingExpectation();
@@ -1,27 +0,0 @@
-/*
-Copyright 2017 Vector creations Ltd
-Copyright 2019 The Matrix.org Foundation C.I.C.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-    http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-import { logger } from "../src/logger";
-
-// try to load the olm library.
-try {
-    // eslint-disable-next-line @typescript-eslint/no-require-imports
-    globalThis.Olm = require("@matrix-org/olm");
-    logger.log("loaded libolm");
-} catch (e) {
-    logger.warn("unable to run crypto tests: libolm not available", e);
-}
@@ -14,13 +14,22 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-jest.mock("../src/http-api/utils", () => ({
-    ...jest.requireActual("../src/http-api/utils"),
+import fetchMock, { manageFetchMockGlobally } from "@fetch-mock/vitest";
+
+vi.mock("../src/http-api/utils", async () => ({
+    ...(await vi.importActual("../src/http-api/utils")),
    // We mock timeoutSignal otherwise it causes tests to leave timers running
    timeoutSignal: () => new AbortController().signal,
 }));

-// Dont make test fail too soon due to timeouts while debugging.
+manageFetchMockGlobally();
+
+beforeEach(() => {
+    fetchMock.hardReset();
+    fetchMock.mockGlobal();
+});
+
+// Don't make test fail too soon due to timeouts while debugging.
 if (process.env.VSCODE_INSPECTOR_OPTIONS) {
-    jest.setTimeout(60 * 1000 * 5); // 5 minutes
+    vi.setConfig({ testTimeout: 60 * 1000 * 5 }); // 5 minutes
 }
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { type ISyncResponder } from "./SyncResponder";

@@ -36,65 +36,80 @@ export class AccountDataAccumulator {

    public constructor(private syncResponder: ISyncResponder) {}

+    private accountDataResolvers = new Map<string, PromiseWithResolvers<any>>();
+    private setInterceptRunning = false;
+
    /**
-     * Intercept requests to set a particular type of account data.
+     * Intercept setting of account data.
     *
     * Once it is set, its data is stored (for future return by `interceptGetAccountData` etc) and the resolved promise is
     * resolved.
     *
-     * @param accountDataType - type of account data to be intercepted
-     * @param opts - options to pass to fetchMock
     * @returns a Promise which will resolve (with the content of the account data) once it is set.
     */
-    public interceptSetAccountData(
-        accountDataType: string,
-        opts?: Parameters<(typeof fetchMock)["put"]>[2],
-    ): Promise<any> {
-        return new Promise((resolve) => {
-            // Called when the cross signing key is uploaded
-            fetchMock.put(
-                `express:/_matrix/client/v3/user/:userId/account_data/${accountDataType}`,
-                (url: string, options: RequestInit) => {
-                    const content = JSON.parse(options.body as string);
-                    const type = url.split("/").pop();
-                    // update account data for sync response
-                    this.accountDataEvents.set(type!, content);
-                    resolve(content);
+    public interceptSetAccountData(): void {
+        if (this.setInterceptRunning) return;
+        this.setInterceptRunning = true;

-                    // return a sync response
-                    this.sendSyncResponseWithUpdatedAccountData();
-                    return {};
-                },
-                opts,
-            );
+        fetchMock.put(`express:/_matrix/client/v3/user/:userId/account_data/:type`, (callLog) => {
+            const content = JSON.parse(callLog.options.body as string);
+            const type = callLog.url.split("/").pop();
+            // update account data for sync response
+            this.accountDataEvents.set(type!, content);
+
+            this.accountDataResolvers.get(type!)?.resolve(content);
+            if (!this.accountDataResolvers.delete(type!)) {
+                // Check for a wildcard matcher
+                for (const [key, resolver] of this.accountDataResolvers) {
+                    if (key.endsWith("*") && type?.startsWith(key.slice(0, -1))) {
+                        resolver.resolve(content);
+                        this.accountDataResolvers.delete(key);
+                    }
+                }
+            }
+
+            // return a sync response
+            this.sendSyncResponseWithUpdatedAccountData();
+            return {};
        });
    }

+    /**
+     * Wait for a particular type of account data.
+     *
+     * Once it is set, its data is stored (for future return by `interceptGetAccountData` etc) and the resolved promise is
+     * resolved.
+     *
+     * @returns a Promise which will resolve (with the content of the account data) once it is set.
+     */
+    public waitForAccountData(type: string): Promise<any> {
+        const resolvers = Promise.withResolvers<any>();
+        this.accountDataResolvers.set(type, resolvers);
+        this.interceptSetAccountData();
+        return resolvers.promise;
+    }
+
    /**
     * Intercept all requests to get account data
     */
    public interceptGetAccountData(): void {
-        fetchMock.get(
-            `express:/_matrix/client/v3/user/:userId/account_data/:type`,
-            (url) => {
-                const type = url.split("/").pop();
-                const existing = this.accountDataEvents.get(type!);
-                if (existing) {
-                    // return it
-                    return {
-                        status: 200,
-                        body: existing,
-                    };
-                } else {
-                    // 404
-                    return {
-                        status: 404,
-                        body: { errcode: "M_NOT_FOUND", error: "Account data not found." },
-                    };
-                }
-            },
-            { overwriteRoutes: true },
-        );
+        fetchMock.get(`express:/_matrix/client/v3/user/:userId/account_data/:type`, (callLog) => {
+            const type = callLog.url.split("/").pop();
+            const existing = this.accountDataEvents.get(type!);
+            if (existing) {
+                // return it
+                return {
+                    status: 200,
+                    body: existing,
+                };
+            } else {
+                // 404
+                return {
+                    status: 404,
+                    body: { errcode: "M_NOT_FOUND", error: "Account data not found." },
+                };
+            }
+        });
    }

    /**
@@ -14,11 +14,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import debugFunc from "debug";
-import { type Debugger } from "debug";
-import fetchMock from "fetch-mock-jest";
+import debugFunc, { type Debugger } from "debug";
+import fetchMock from "@fetch-mock/vitest";

 import type { IDeviceKeys, IOneTimeKey } from "../../src/@types/crypto";
+import type { CrossSigningKeys, ISignedKey, KeySignatures } from "../../src";
+import type { CrossSigningKeyInfo } from "../../src/crypto-api";

 /** Interface implemented by classes that intercept `/keys/upload` requests from test clients to catch the uploaded keys
 *
@@ -55,28 +56,53 @@ export class E2EKeyReceiver implements IE2EKeyReceiver {
    private readonly debug: Debugger;

    private deviceKeys: IDeviceKeys | null = null;
+    private crossSigningKeys: CrossSigningKeys | null = null;
    private oneTimeKeys: Record<string, IOneTimeKey> = {};
    private readonly oneTimeKeysPromise: Promise<void>;

    /**
     * Construct a new E2EKeyReceiver.
     *
-     * It will immediately register an intercept of `/keys/uploads` requests for the given homeserverUrl.
-     * Only /upload requests made to this server will be intercepted: this allows a single test to use more than one
+     * It will immediately register an intercept of [`/keys/upload`][1], [`/keys/signatures/upload`][2] and
+     * [`/keys/device_signing/upload`][3] requests for the given homeserverUrl.
+     * Only requests made to this server will be intercepted: this allows a single test to use more than one
     * client and have the keys collected separately.
     *
-     * @param homeserverUrl - the Homeserver Url of the client under test.
+     * [1]: https://spec.matrix.org/v1.14/client-server-api/#post_matrixclientv3keysupload
+     * [2]: https://spec.matrix.org/v1.14/client-server-api/#post_matrixclientv3keyssignaturesupload
+     * [3]: https://spec.matrix.org/v1.14/client-server-api/#post_matrixclientv3keysdevice_signingupload
+     *
+     * @param homeserverUrl - The Homeserver Url of the client under test.
+     * @param routeNamePrefix - An optional prefix to add to the fetchmock route names. Required if there is more than
+     *    one E2EKeyReceiver instance active.
     */
-    public constructor(homeserverUrl: string) {
+    public constructor(homeserverUrl: string, routeNamePrefix: string = "") {
        this.debug = debugFunc(`e2e-key-receiver:[${homeserverUrl}]`);

        // set up a listener for /keys/upload.
        this.oneTimeKeysPromise = new Promise((resolveOneTimeKeys) => {
-            const listener = (url: string, options: RequestInit) =>
-                this.onKeyUploadRequest(resolveOneTimeKeys, options);
-
-            fetchMock.post(new URL("/_matrix/client/v3/keys/upload", homeserverUrl).toString(), listener);
+            fetchMock.post(
+                new URL("/_matrix/client/v3/keys/upload", homeserverUrl).toString(),
+                (callLog) => this.onKeyUploadRequest(resolveOneTimeKeys, callLog.options),
+                { name: routeNamePrefix + "keys-upload" },
+            );
        });
+
+        fetchMock.post(
+            new URL("/_matrix/client/v3/keys/signatures/upload", homeserverUrl).toString(),
+            (callLog) => this.onSignaturesUploadRequest(callLog.options),
+            {
+                name: routeNamePrefix + "upload-sigs",
+            },
+        );
+
+        fetchMock.post(
+            new URL("/_matrix/client/v3/keys/device_signing/upload", homeserverUrl).toString(),
+            (callLog) => this.onSigningKeyUploadRequest(callLog.options),
+            {
+                name: routeNamePrefix + "upload-cross-signing-keys",
+            },
+        );
    }

    private async onKeyUploadRequest(onOnTimeKeysUploaded: () => void, options: RequestInit): Promise<object> {
@@ -87,8 +113,10 @@ export class E2EKeyReceiver implements IE2EKeyReceiver {
            if (this.deviceKeys) {
                throw new Error("Application attempted to upload E2E device keys multiple times");
            }
-            this.debug(`received device keys`);
            this.deviceKeys = content.device_keys;
+            this.debug(
+                `received device keys for user ID ${this.deviceKeys!.user_id}, device ID ${this.deviceKeys!.device_id}`,
+            );
        }

        if (content.one_time_keys && Object.keys(content.one_time_keys).length > 0) {
@@ -113,6 +141,47 @@ export class E2EKeyReceiver implements IE2EKeyReceiver {
        };
    }

+    private async onSignaturesUploadRequest(request: RequestInit): Promise<object> {
+        const content = JSON.parse(request.body as string) as KeySignatures;
+        for (const [userId, userKeys] of Object.entries(content)) {
+            for (const [deviceId, signedKey] of Object.entries(userKeys)) {
+                this.onDeviceSignatureUpload(userId, deviceId, signedKey);
+            }
+        }
+
+        return {};
+    }
+
+    private onDeviceSignatureUpload(userId: string, deviceId: string, signedKey: CrossSigningKeyInfo | ISignedKey) {
+        if (!this.deviceKeys || userId != this.deviceKeys.user_id || deviceId != this.deviceKeys.device_id) {
+            this.debug(
+                `Ignoring device key signature upload for unknown device user ID ${userId}, device ID ${deviceId}`,
+            );
+            return;
+        }
+
+        this.debug(`received device key signature for user ID ${userId}, device ID ${deviceId}`);
+        this.deviceKeys.signatures ??= {};
+        for (const [signingUser, signatures] of Object.entries(signedKey.signatures!)) {
+            this.deviceKeys.signatures[signingUser] = Object.assign(
+                this.deviceKeys.signatures[signingUser] ?? {},
+                signatures,
+            );
+        }
+    }
+
+    private async onSigningKeyUploadRequest(request: RequestInit): Promise<object> {
+        const content = JSON.parse(request.body as string);
+        if (this.crossSigningKeys) {
+            throw new Error("Application attempted to upload E2E cross-signing keys multiple times");
+        }
+        this.debug(`received cross-signing keys`);
+        // Remove UIA data
+        delete content["auth"];
+        this.crossSigningKeys = content;
+        return {};
+    }
+
    /** Get the uploaded Ed25519 key
     *
     * If device keys have not yet been uploaded, throws an error
@@ -150,6 +219,13 @@ export class E2EKeyReceiver implements IE2EKeyReceiver {
        return this.deviceKeys;
    }

+    /**
+     * If cross-signing keys have been uploaded, return them. Else return null.
+     */
+    public getUploadedCrossSigningKeys(): CrossSigningKeys | null {
+        return this.crossSigningKeys;
+    }
+
    /**
     * If one-time keys have already been uploaded, return them. Otherwise,
     * set up an expectation that the keys will be uploaded, and wait for
@@ -161,4 +237,18 @@ export class E2EKeyReceiver implements IE2EKeyReceiver {
        await this.oneTimeKeysPromise;
        return this.oneTimeKeys;
    }
+
+    /**
+     * If no one-time keys have yet been uploaded, return `null`.
+     * Otherwise, pop a key from the uploaded list.
+     */
+    public getOneTimeKey(): [string, IOneTimeKey] | null {
+        const keys = Object.entries(this.oneTimeKeys);
+        if (keys.length == 0) {
+            return null;
+        }
+        const [otkId, otk] = keys[0];
+        delete this.oneTimeKeys[otkId];
+        return [otkId, otk];
+    }
 }
@@ -14,10 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { MapWithDefault } from "../../src/utils";
-import { type IDownloadKeyResult } from "../../src";
+import { type IDownloadKeyResult, type SigningKeys } from "../../src";
 import { type IDeviceKeys } from "../../src/@types/crypto";
 import { type E2EKeyReceiver } from "./E2EKeyReceiver";

@@ -42,26 +42,23 @@ export class E2EKeyResponder {
     */
    public constructor(homeserverUrl: string) {
        // set up a listener for /keys/query.
-        const listener = (url: string, options: RequestInit) => this.onKeyQueryRequest(options);
-        fetchMock.post(new URL("/_matrix/client/v3/keys/query", homeserverUrl).toString(), listener);
+        fetchMock.post(new URL("/_matrix/client/v3/keys/query", homeserverUrl).toString(), (callLog) =>
+            this.onKeyQueryRequest(callLog.options),
+        );
    }

    private onKeyQueryRequest(options: RequestInit) {
        const content = JSON.parse(options.body as string);
        const usersToReturn = Object.keys(content["device_keys"]);
        const response = {
-            device_keys: {} as { [userId: string]: any },
-            master_keys: {} as { [userId: string]: any },
-            self_signing_keys: {} as { [userId: string]: any },
-            user_signing_keys: {} as { [userId: string]: any },
-            failures: {} as { [serverName: string]: any },
-        };
+            device_keys: {},
+            master_keys: {},
+            self_signing_keys: {},
+            user_signing_keys: {},
+            failures: {},
+        } as IDownloadKeyResult;
        for (const user of usersToReturn) {
-            const userKeys = this.deviceKeysByUserByDevice.get(user);
-            if (userKeys !== undefined) {
-                response.device_keys[user] = Object.fromEntries(userKeys.entries());
-            }
-
+            // First see if we have an E2EKeyReceiver for this user, and if so, return any keys that have been uploaded
            const e2eKeyReceiver = this.e2eKeyReceiversByUser.get(user);
            if (e2eKeyReceiver !== undefined) {
                const deviceKeys = e2eKeyReceiver.getUploadedDeviceKeys();
@@ -69,16 +66,27 @@ export class E2EKeyResponder {
                    response.device_keys[user] ??= {};
                    response.device_keys[user][deviceKeys.device_id] = deviceKeys;
                }
+                const crossSigningKeys = e2eKeyReceiver.getUploadedCrossSigningKeys();
+                if (crossSigningKeys !== null) {
+                    response.master_keys![user] = crossSigningKeys["master_key"];
+                    response.self_signing_keys![user] = crossSigningKeys["self_signing_key"] as SigningKeys;
+                }
            }

+            // Mix in any keys that have been added explicitly to this E2EKeyResponder.
+            const userKeys = this.deviceKeysByUserByDevice.get(user);
+            if (userKeys !== undefined) {
+                response.device_keys[user] ??= {};
+                Object.assign(response.device_keys[user], Object.fromEntries(userKeys.entries()));
+            }
            if (this.masterKeysByUser.hasOwnProperty(user)) {
-                response.master_keys[user] = this.masterKeysByUser[user];
+                response.master_keys![user] = this.masterKeysByUser[user];
            }
            if (this.selfSigningKeysByUser.hasOwnProperty(user)) {
-                response.self_signing_keys[user] = this.selfSigningKeysByUser[user];
+                response.self_signing_keys![user] = this.selfSigningKeysByUser[user];
            }
            if (this.userSigningKeysByUser.hasOwnProperty(user)) {
-                response.user_signing_keys[user] = this.userSigningKeysByUser[user];
+                response.user_signing_keys![user] = this.userSigningKeysByUser[user];
            }
        }
        return response;
@@ -0,0 +1,74 @@
+/*
+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 fetchMock from "@fetch-mock/vitest";
+
+import { MapWithDefault } from "../../src/utils";
+import { type E2EKeyReceiver } from "./E2EKeyReceiver";
+import { type IClaimKeysRequest } from "../../src";
+
+/**
+ * An object which intercepts `/keys/claim` fetches via fetch-mock.
+ */
+export class E2EOTKClaimResponder {
+    private e2eKeyReceiversByUserByDevice = new MapWithDefault<string, Map<string, E2EKeyReceiver>>(() => new Map());
+
+    /**
+     * Construct a new E2EOTKClaimResponder.
+     *
+     * It will immediately register an intercept of `/keys/claim` requests for the given homeserverUrl.
+     * Only /claim requests made to this server will be intercepted: this allows a single test to use more than one
+     * client and have the keys collected separately.
+     *
+     * @param homeserverUrl - the Homeserver Url of the client under test.
+     */
+    public constructor(homeserverUrl: string) {
+        fetchMock.post(new URL("/_matrix/client/v3/keys/claim", homeserverUrl).toString(), (callLog) =>
+            this.onKeyClaimRequest(callLog.options),
+        );
+    }
+
+    private onKeyClaimRequest(options: RequestInit) {
+        const content = JSON.parse(options.body as string) as IClaimKeysRequest;
+        const response = {
+            one_time_keys: {} as { [userId: string]: any },
+        };
+        for (const [userId, devices] of Object.entries(content["one_time_keys"])) {
+            for (const deviceId of Object.keys(devices)) {
+                const e2eKeyReceiver = this.e2eKeyReceiversByUserByDevice.get(userId)?.get(deviceId);
+                const otk = e2eKeyReceiver?.getOneTimeKey();
+                if (otk) {
+                    const [keyId, key] = otk;
+                    response.one_time_keys[userId] ??= {};
+                    response.one_time_keys[userId][deviceId] = {
+                        [keyId]: key,
+                    };
+                }
+            }
+        }
+        return response;
+    }
+
+    /**
+     * Add an E2EKeyReceiver to poll for uploaded keys
+     *
+     * When the `/keys/claim` request is received, a OTK will be removed from the `E2EKeyReceiver` and
+     * added to the response.
+     */
+    public addKeyReceiver(userId: string, deviceId: string, e2eKeyReceiver: E2EKeyReceiver) {
+        this.e2eKeyReceiversByUserByDevice.getOrCreate(userId).set(deviceId, e2eKeyReceiver);
+    }
+}
@@ -16,9 +16,8 @@ limitations under the License.

 import debugFunc from "debug";
 import { type Debugger } from "debug";
-import fetchMock from "fetch-mock-jest";
-
-import type FetchMock from "fetch-mock";
+import fetchMock from "@fetch-mock/vitest";
+import { type RouteResponse } from "fetch-mock";

 /** Interface implemented by classes that intercept `/sync` requests from test clients
 *
@@ -76,12 +75,12 @@ export class SyncResponder implements ISyncResponder {
     */
    public constructor(homeserverUrl: string) {
        this.debug = debugFunc(`sync-responder:[${homeserverUrl}]`);
-        fetchMock.get("begin:" + new URL("/_matrix/client/v3/sync?", homeserverUrl).toString(), (_url, _options) =>
+        fetchMock.get("begin:" + new URL("/_matrix/client/v3/sync?", homeserverUrl).toString(), (callLog) =>
            this.onSyncRequest(),
        );
    }

-    private async onSyncRequest(): Promise<FetchMock.MockResponse> {
+    private async onSyncRequest(): Promise<RouteResponse> {
        switch (this.state) {
            case SyncResponderState.IDLE: {
                this.debug("Got /sync request: waiting for response to be ready");
@@ -14,12 +14,18 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { type MethodLikeKeys, mocked, type MockedObject } from "jest-mock";
+import { type MockedObject } from "vitest";

 import { type ClientEventHandlerMap, type EmittedEvents, type MatrixClient } from "../../src/client";
 import { TypedEventEmitter } from "../../src/models/typed-event-emitter";
 import { User } from "../../src/models/user";

+// Cribbed from https://github.com/jestjs/jest/blob/94830794dc5dfca1b49bc435b7b031b27838a798/packages/jest-mock/src/index.ts
+type FunctionLike = (...args: any) => any;
+type MethodLikeKeys<T> = keyof {
+    [K in keyof T as Required<T>[K] extends FunctionLike ? K : never]: T[K];
+};
+
 /**
 * Mock client with real event emitter
 * useful for testing code that listens
@@ -34,19 +40,19 @@ export class MockClientWithEventEmitter extends TypedEventEmitter<EmittedEvents,

 /**
 * - make a mock client
- * - cast the type to mocked(MatrixClient)
+ * - cast the type to vi.mocked(MatrixClient)
 * - spy on MatrixClientPeg.get to return the mock
 * eg
 * ```
 * const mockClient = getMockClientWithEventEmitter({
-        getUserId: jest.fn().mockReturnValue(aliceId),
+        getUserId: vi.fn().mockReturnValue(aliceId),
    });
 * ```
 */
 export const getMockClientWithEventEmitter = (
    mockProperties: Partial<Record<MethodLikeKeys<MatrixClient>, unknown>>,
 ): MockedObject<MatrixClient> => {
-    const mock = mocked(new MockClientWithEventEmitter(mockProperties) as unknown as MatrixClient);
+    const mock = vi.mocked(new MockClientWithEventEmitter(mockProperties) as unknown as MatrixClient);
    return mock;
 };

@@ -59,14 +65,14 @@ export const getMockClientWithEventEmitter = (
 * ```
 */
 export const mockClientMethodsUser = (userId = "@alice:domain") => ({
-    getUserId: jest.fn().mockReturnValue(userId),
-    getSafeUserId: jest.fn().mockReturnValue(userId),
-    getUser: jest.fn().mockReturnValue(new User(userId)),
-    isGuest: jest.fn().mockReturnValue(false),
-    mxcUrlToHttp: jest.fn().mockReturnValue("mock-mxcUrlToHttp"),
+    getUserId: vi.fn().mockReturnValue(userId),
+    getSafeUserId: vi.fn().mockReturnValue(userId),
+    getUser: vi.fn().mockReturnValue(new User(userId)),
+    isGuest: vi.fn().mockReturnValue(false),
+    mxcUrlToHttp: vi.fn().mockReturnValue("mock-mxcUrlToHttp"),
    credentials: { userId },
-    getThreePids: jest.fn().mockResolvedValue({ threepids: [] }),
-    getAccessToken: jest.fn(),
+    getThreePids: vi.fn().mockResolvedValue({ threepids: [] }),
+    getAccessToken: vi.fn(),
 });

 /**
@@ -78,16 +84,16 @@ export const mockClientMethodsUser = (userId = "@alice:domain") => ({
 * ```
 */
 export const mockClientMethodsEvents = () => ({
-    decryptEventIfNeeded: jest.fn(),
-    getPushActionsForEvent: jest.fn(),
+    decryptEventIfNeeded: vi.fn(),
+    getPushActionsForEvent: vi.fn(),
 });

 /**
 * Returns basic mocked client methods related to server support
 */
 export const mockClientMethodsServer = (): Partial<Record<MethodLikeKeys<MatrixClient>, unknown>> => ({
-    getIdentityServerUrl: jest.fn(),
-    getHomeserverUrl: jest.fn(),
-    getCachedCapabilities: jest.fn().mockReturnValue({}),
-    doesServerSupportUnstableFeature: jest.fn().mockResolvedValue(false),
+    getIdentityServerUrl: vi.fn(),
+    getHomeserverUrl: vi.fn(),
+    getCachedCapabilities: vi.fn().mockReturnValue({}),
+    doesServerSupportUnstableFeature: vi.fn().mockResolvedValue(false),
 });
@@ -14,15 +14,17 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

+import { type MockInstance } from "vitest";
+
 /**
 * Filter emitter.emit mock calls to find relevant events
 * eg:
 * ```
- * const emitSpy = jest.spyOn(state, 'emit');
+ * const emitSpy = vi.spyOn(state, 'emit');
 * << actions >>
 * const beaconLivenessEmits = emitCallsByEventType(BeaconEvent.New, emitSpy);
 * expect(beaconLivenessEmits.length).toBe(1);
 * ```
 */
-export const filterEmitCallsByEventType = (eventType: string, spy: jest.SpyInstance<any, any[]>) =>
+export const filterEmitCallsByEventType = (eventType: string, spy: MockInstance<(...args: any[]) => any>) =>
    spy.mock.calls.filter((args) => args[0] === eventType);
@@ -14,12 +14,10 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-// Jest now uses @sinonjs/fake-timers which exposes tickAsync() and a number of
-// other async methods which break the event loop, letting scheduled promise
-// callbacks run. Unfortunately, Jest doesn't expose these, so we have to do
-// it manually (this is what sinon does under the hood). We do both in a loop
-// until the thing we expect happens: hopefully this is the least flakey way
-// and avoids assuming anything about the app's behaviour.
+// Vitest lacks tickAsync() and a number of other async methods which break the event loop,
+// letting scheduled promise callbacks run. So we have to do it manually
+// (this is what sinon does under the hood). We do both in a loop until the thing we expect happens:
+// hopefully this is the least flakey way and avoids assuming anything about the app's behaviour.
 const realSetTimeout = setTimeout;
 export function flushPromises() {
    return new Promise((r) => {
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { type KeyBackupInfo } from "../../src/crypto-api";

@@ -25,29 +25,22 @@ import { type KeyBackupInfo } from "../../src/crypto-api";
 * @param userId - the local user's ID. Defaults to `@alice:localhost`.
 */
 export function mockInitialApiRequests(homeserverUrl: string, userId: string = "@alice:localhost") {
-    fetchMock.getOnce(
-        new URL("/_matrix/client/versions", homeserverUrl).toString(),
-        { versions: ["v1.1"] },
-        { overwriteRoutes: true },
-    );
-    fetchMock.getOnce(
-        new URL("/_matrix/client/v3/pushrules/", homeserverUrl).toString(),
-        {},
-        { overwriteRoutes: true },
-    );
+    fetchMock.getOnce(new URL("/_matrix/client/versions", homeserverUrl).toString(), { versions: ["v1.1"] });
+    fetchMock.getOnce(new URL("/_matrix/client/v3/pushrules/", homeserverUrl).toString(), {});
    fetchMock.postOnce(
        new URL(`/_matrix/client/v3/user/${encodeURIComponent(userId)}/filter`, homeserverUrl).toString(),
        { filter_id: "fid" },
-        { overwriteRoutes: true },
+    );
+    fetchMock.getOnce(
+        new URL(`/_matrix/client/v3/user/${encodeURIComponent(userId)}/filter/fid`, homeserverUrl).toString(),
+        { filter_id: "fid" },
    );
 }

 /**
- * Mock the requests needed to set up cross signing
+ * Mock the requests needed to set up cross signing, besides those provided by {@link E2EKeyReceiver}.
 *
 * Return 404 error for `GET _matrix/client/v3/user/:userId/account_data/:type` request
- * Return `{}` for `POST _matrix/client/v3/keys/signatures/upload` request (named `upload-sigs` for fetchMock check)
- * Return `{}` for `POST /_matrix/client/(unstable|v3)/keys/device_signing/upload` request (named `upload-keys` for fetchMock check)
 */
 export function mockSetupCrossSigningRequests(): void {
    // have account_data requests return an empty object
@@ -55,19 +48,6 @@ export function mockSetupCrossSigningRequests(): void {
        status: 404,
        body: { errcode: "M_NOT_FOUND", error: "Account data not found." },
    });
-
-    // we expect a request to upload signatures for our device ...
-    fetchMock.post({ url: "path:/_matrix/client/v3/keys/signatures/upload", name: "upload-sigs" }, {});
-
-    // ... and one to upload the cross-signing keys (with UIA)
-    fetchMock.post(
-        // legacy crypto uses /unstable/; /v3/ is correct
-        {
-            url: new RegExp("/_matrix/client/(unstable|v3)/keys/device_signing/upload"),
-            name: "upload-keys",
-        },
-        {},
-    );
 }

 /**
@@ -80,24 +60,30 @@ export function mockSetupCrossSigningRequests(): void {
 * @param backupVersion - The backup version that will be returned by `POST room_keys/version`.
 */
 export function mockSetupMegolmBackupRequests(backupVersion: string): void {
-    fetchMock.get("path:/_matrix/client/v3/room_keys/version", {
-        status: 404,
-        body: {
-            errcode: "M_NOT_FOUND",
-            error: "No current backup version",
+    fetchMock.get(
+        "path:/_matrix/client/v3/room_keys/version",
+        {
+            status: 404,
+            body: {
+                errcode: "M_NOT_FOUND",
+                error: "No current backup version",
+            },
        },
-    });
+        { name: "room-keys-version" },
+    );

-    fetchMock.post("path:/_matrix/client/v3/room_keys/version", (url, request) => {
-        const backupData: KeyBackupInfo = JSON.parse((request.body as string) ?? "{}");
-        backupData.version = backupVersion;
-        backupData.count = 0;
-        backupData.etag = "zer";
-        fetchMock.get("path:/_matrix/client/v3/room_keys/version", backupData, {
-            overwriteRoutes: true,
-        });
-        return {
-            version: backupVersion,
-        };
-    });
+    fetchMock.post(
+        "path:/_matrix/client/v3/room_keys/version",
+        (callLog) => {
+            const backupData: KeyBackupInfo = JSON.parse((callLog.options.body as string) ?? "{}");
+            backupData.version = backupVersion;
+            backupData.count = 0;
+            backupData.etag = "zer";
+            fetchMock.modifyRoute("room-keys-version", { response: backupData });
+            return {
+                version: backupVersion,
+            };
+        },
+        { name: "post-room-keys-version" },
+    );
 }
@@ -84,9 +84,9 @@ def main() -> None:
 * Do not edit by hand! This file is generated by `./generate-test-data.py`
 */

-import {{ IDeviceKeys, IMegolmSessionData }} from "../../../src/@types/crypto";
-import {{ IDownloadKeyResult, IEvent }} from "../../../src";
-import {{ KeyBackupSession, KeyBackupInfo }} from "../../../src/crypto-api/keybackup";
+import type {{ IDeviceKeys, IMegolmSessionData }} from "../../../src/@types/crypto";
+import type {{ IDownloadKeyResult, IEvent }} from "../../../src";
+import type {{ KeyBackupSession, KeyBackupInfo, KeyBackupRoomSessions }} from "../../../src/crypto-api/keybackup";

 /* eslint-disable comma-dangle */

@@ -246,15 +246,6 @@ export const {prefix}SIGNED_CROSS_SIGNING_KEYS_DATA: Partial<IDownloadKeyResult>
 /** Signed OTKs, returned by `POST /keys/claim` */
 export const {prefix}ONE_TIME_KEYS = { json.dumps(otks, indent=4) };

-/** base64-encoded backup decryption (private) key */
-export const {prefix}BACKUP_DECRYPTION_KEY_BASE64 = "{ user_data['B64_BACKUP_DECRYPTION_KEY'] }";
-
-/** Backup decryption key in export format */
-export const {prefix}BACKUP_DECRYPTION_KEY_BASE58 = "{ backup_recovery_key }";
-
-/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{{roomId}}/{{sessionId}}` */
-export const {prefix}SIGNED_BACKUP_DATA: KeyBackupInfo = { json.dumps(backup_data, indent=4) };
-
 /** A set of megolm keys that can be imported via CryptoAPI#importRoomKeys */
 export const {prefix}MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = {
    json.dumps(set_of_exported_room_keys, indent=4)
@@ -278,6 +269,23 @@ export const {prefix}CLEAR_EVENT: Partial<IEvent> = {json.dumps(clear_event, ind

 /** The encrypted CLEAR_EVENT by MEGOLM_SESSION_DATA */
 export const {prefix}ENCRYPTED_EVENT: Partial<IEvent> = {json.dumps(encrypted_event, indent=4)};
+
+/** base64-encoded backup decryption (private) key */
+export const {prefix}BACKUP_DECRYPTION_KEY_BASE64 = "{ user_data['B64_BACKUP_DECRYPTION_KEY'] }";
+
+/** Backup decryption key in export format */
+export const {prefix}BACKUP_DECRYPTION_KEY_BASE58 = "{ backup_recovery_key }";
+
+/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{{roomId}}/{{sessionId}}` */
+export const {prefix}SIGNED_BACKUP_DATA: KeyBackupInfo = { json.dumps(backup_data, indent=4) };
+
+/**
+ * Per-room backup data, (supposedly) suitable for return from `GET /_matrix/client/v3/room_keys/keys/{{roomId}}`.
+ * Contains the key from {prefix}MEGOLM_SESSION_DATA.
+ */
+export const {prefix}PER_ROOM_CURVE25519_KEY_BACKUP_DATA: KeyBackupRoomSessions = {{
+     [{prefix}MEGOLM_SESSION_DATA.session_id]: {prefix}CURVE25519_KEY_BACKUP_DATA
+}};
 """

    alt_master_key = user_data.get("ALT_MASTER_CROSS_SIGNING_PRIVATE_KEY_BYTES")
@@ -385,7 +393,7 @@ def sign_json(json_object: dict, private_key: ed25519.Ed25519PrivateKey) -> str:
 def build_exported_megolm_key(device_curve_key: x25519.X25519PrivateKey) -> tuple[dict, ed25519.Ed25519PrivateKey]:
    """
    Creates an exported megolm room key, as per https://gitlab.matrix.org/matrix-org/olm/blob/master/docs/megolm.md#session-export-format
-    that can be imported via importRoomKeys API.
+    that can be imported via importRoomKeys API, or shared via MSC4268 room history sharing.
    Returns the exported key, the matching privat edKey (needed to encrypt)
    """
    index = 0
@@ -409,11 +417,12 @@ def build_exported_megolm_key(device_curve_key: x25519.X25519PrivateKey) -> tupl
        "session_id": encode_base64(
            private_key.public_key().public_bytes(Encoding.Raw, PublicFormat.Raw)
        ),
-        "session_key": encode_base64(exported_key),
+        "session_key": encode_base64(bytes(exported_key)),
        "sender_claimed_keys": {
            "ed25519": encode_base64(ed25519.Ed25519PrivateKey.from_private_bytes(randbytes(32)).public_key().public_bytes(Encoding.Raw, PublicFormat.Raw)),
        },
        "forwarding_curve25519_key_chain": [],
+        "m.shared_history": True,
    }

    return megolm_export, private_key
@@ -458,7 +467,7 @@ def symetric_ratchet_step_of_megolm_key(previous: dict , megolm_private_key: ed2
        "room_id": "!room:id",
        "sender_key": previous["sender_key"],
        "session_id": previous["session_id"],
-        "session_key": encode_base64(exported_key),
+        "session_key": encode_base64(bytes(exported_key)),
        "sender_claimed_keys": previous["sender_claimed_keys"],
        "forwarding_curve25519_key_chain": [],
    }
@@ -609,7 +618,7 @@ def generate_encrypted_event_content(exported_key: dict, ed_key: ed25519.Ed25519

    message += signature

-    cipher_text = encode_base64(message)
+    cipher_text = encode_base64(bytes(message))

    encrypted_payload = {
        "algorithm" : "m.megolm.v1.aes-sha2",
@@ -653,7 +662,7 @@ def export_recovery_key(key_b64: str) -> str:
    export_bytes += parity_byte.to_bytes(1, 'big')

    # The byte string is encoded using base58
-    recovery_key = base58.b58encode(export_bytes).decode('utf-8')
+    recovery_key = base58.b58encode(bytes(export_bytes)).decode('utf-8')

    split = [recovery_key[i:i + 4] for i in range(0, len(recovery_key), 4)]
    return ' '.join(split)
@@ -3,9 +3,9 @@
 * Do not edit by hand! This file is generated by `./generate-test-data.py`
 */

-import { type IDeviceKeys, type IMegolmSessionData } from "../../../src/@types/crypto";
-import { type IDownloadKeyResult, type IEvent } from "../../../src";
-import { type KeyBackupSession, type KeyBackupInfo } from "../../../src/crypto-api/keybackup";
+import type { IDeviceKeys, IMegolmSessionData } from "../../../src/@types/crypto";
+import type { IDownloadKeyResult, IEvent } from "../../../src";
+import type { KeyBackupSession, KeyBackupInfo, KeyBackupRoomSessions } from "../../../src/crypto-api/keybackup";

 /* eslint-disable comma-dangle */

@@ -118,26 +118,6 @@ export const ONE_TIME_KEYS = {
    }
 };

-/** base64-encoded backup decryption (private) key */
-export const BACKUP_DECRYPTION_KEY_BASE64 = "dwdtCnMYpX08FsFyUbJmRd9ML4frwJkqsXf7pR25LCo=";
-
-/** Backup decryption key in export format */
-export const BACKUP_DECRYPTION_KEY_BASE58 = "EsTc LW2K PGiF wKEA 3As5 g5c4 BXwk qeeJ ZJV8 Q9fu gUMN UE4d";
-
-/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}/{sessionId}` */
-export const SIGNED_BACKUP_DATA: KeyBackupInfo = {
-    "algorithm": "m.megolm_backup.v1.curve25519-aes-sha2",
-    "version": "1",
-    "auth_data": {
-        "public_key": "hSDwCYkwp1R0i33ctD73Wg2/Og0mOBr066SpjqqbTmo",
-        "signatures": {
-            "@alice:localhost": {
-                "ed25519:test_device": "KDSNeumirTsd8piI0oVfv/wzg4J4HlEc7rs5XhODFcJ/YAcUdg65ajsZG+rLI0TQOSSGjorJqcrSiSB1HRSCAA"
-            }
-        }
-    }
-};
-
 /** A set of megolm keys that can be imported via CryptoAPI#importRoomKeys */
 export const MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
    {
@@ -149,7 +129,8 @@ export const MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
        "sender_claimed_keys": {
            "ed25519": "QdgHgdpDgihgovpPzUiThXur1fbErTFh7paFvNKSgN0"
        },
-        "forwarding_curve25519_key_chain": []
+        "forwarding_curve25519_key_chain": [],
+        "org.matrix.msc3061.shared_history": true
    },
    {
        "algorithm": "m.megolm.v1.aes-sha2",
@@ -160,7 +141,8 @@ export const MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
        "sender_claimed_keys": {
            "ed25519": "IrkbT6H+0urDf6wKDSyVC1fh1t84Vz6T62snni86Cog"
        },
-        "forwarding_curve25519_key_chain": []
+        "forwarding_curve25519_key_chain": [],
+        "org.matrix.msc3061.shared_history": true
    }
 ];

@@ -174,7 +156,8 @@ export const MEGOLM_SESSION_DATA: IMegolmSessionData = {
    "sender_claimed_keys": {
        "ed25519": "Bhbpt6hqMZlSH4sJV7xiEEEiPVeTWz4Vkujl1EMdIPI"
    },
-    "forwarding_curve25519_key_chain": []
+    "forwarding_curve25519_key_chain": [],
+    "org.matrix.msc3061.shared_history": true
 };

 /** A ratcheted version of MEGOLM_SESSION_DATA */
@@ -196,7 +179,7 @@ export const CURVE25519_KEY_BACKUP_DATA: KeyBackupSession = {
    "forwarded_count": 0,
    "is_verified": false,
    "session_data": {
-        "ciphertext": "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",
+        "ciphertext": "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",
        "ephemeral": "q+P1WdRtEiPIEtNuuGrRcueZxUbLnSKdsuTAkxewXgU",
        "mac": "OibmACbORhI"
    }
@@ -229,6 +212,37 @@ export const ENCRYPTED_EVENT: Partial<IEvent> = {
    "origin_server_ts": 1507753886000
 };

+/** base64-encoded backup decryption (private) key that matches the public key in CURVE25519_KEY_BACKUP_DATA */
+export const BACKUP_DECRYPTION_KEY_BASE64 = "dwdtCnMYpX08FsFyUbJmRd9ML4frwJkqsXf7pR25LCo=";
+
+/** base64-encoded backup decryption (private) key that does not match the public key in CURVE25519_KEY_BACKUP_DATA */
+export const BACKUP_DECRYPTION_KEY_BASE64_ALT = "dh4fP2LITyJusgnb0dEq/SQK253WGObvLxXF5FEX6qc";
+
+/** Backup decryption key in export format */
+export const BACKUP_DECRYPTION_KEY_BASE58 = "EsTc LW2K PGiF wKEA 3As5 g5c4 BXwk qeeJ ZJV8 Q9fu gUMN UE4d";
+
+/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}/{sessionId}` */
+export const SIGNED_BACKUP_DATA: KeyBackupInfo = {
+    "algorithm": "m.megolm_backup.v1.curve25519-aes-sha2",
+    "version": "1",
+    "auth_data": {
+        "public_key": "hSDwCYkwp1R0i33ctD73Wg2/Og0mOBr066SpjqqbTmo",
+        "signatures": {
+            "@alice:localhost": {
+                "ed25519:test_device": "KDSNeumirTsd8piI0oVfv/wzg4J4HlEc7rs5XhODFcJ/YAcUdg65ajsZG+rLI0TQOSSGjorJqcrSiSB1HRSCAA"
+            }
+        }
+    }
+};
+
+/**
+ * Per-room backup data, (supposedly) suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}`.
+ * Contains the key from MEGOLM_SESSION_DATA.
+ */
+export const PER_ROOM_CURVE25519_KEY_BACKUP_DATA: KeyBackupRoomSessions = {
+     [MEGOLM_SESSION_DATA.session_id]: CURVE25519_KEY_BACKUP_DATA
+};
+
 // Bob data

 export const BOB_TEST_USER_ID = "@bob:xyz";
@@ -338,26 +352,6 @@ export const BOB_ONE_TIME_KEYS = {
    }
 };

-/** base64-encoded backup decryption (private) key */
-export const BOB_BACKUP_DECRYPTION_KEY_BASE64 = "DwdtCnMYpX08FsFyUbJmRd9ML4frwJkqsXf7pR25LCo=";
-
-/** Backup decryption key in export format */
-export const BOB_BACKUP_DECRYPTION_KEY_BASE58 = "EsT5 Sd5m mEXs NQYE ibRe 3q9E 4aXW rHih 5f9J 6rU6 AfwY mASR";
-
-/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}/{sessionId}` */
-export const BOB_SIGNED_BACKUP_DATA: KeyBackupInfo = {
-    "algorithm": "m.megolm_backup.v1.curve25519-aes-sha2",
-    "version": "1",
-    "auth_data": {
-        "public_key": "ZRuVWcWlDuvOwZRygccUCD4Avtnt130800I+WQNwwRY",
-        "signatures": {
-            "@bob:xyz": {
-                "ed25519:bob_device": "lDIMj3VC0WazE2FamGHpmbiqKf9Z4pO4qapZ5TL5BnD3c+dvb+2waOEd6pgay/pmrQ6MW4Eu2KDEpe1fnHc3BA"
-            }
-        }
-    }
-};
-
 /** A set of megolm keys that can be imported via CryptoAPI#importRoomKeys */
 export const BOB_MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
    {
@@ -369,7 +363,8 @@ export const BOB_MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
        "sender_claimed_keys": {
            "ed25519": "F4P7f1Z0RjbiZMgHk1xBCG3KC4/Ng9PmxLJ4hQ13sHA"
        },
-        "forwarding_curve25519_key_chain": []
+        "forwarding_curve25519_key_chain": [],
+        "org.matrix.msc3061.shared_history": true
    },
    {
        "algorithm": "m.megolm.v1.aes-sha2",
@@ -380,7 +375,8 @@ export const BOB_MEGOLM_SESSION_DATA_ARRAY: IMegolmSessionData[] = [
        "sender_claimed_keys": {
            "ed25519": "OsZMdC1gQ5nPr+L9tuT6xXsaFJkVPkgxP2FexHF1/QM"
        },
-        "forwarding_curve25519_key_chain": []
+        "forwarding_curve25519_key_chain": [],
+        "org.matrix.msc3061.shared_history": true
    }
 ];

@@ -394,7 +390,8 @@ export const BOB_MEGOLM_SESSION_DATA: IMegolmSessionData = {
    "sender_claimed_keys": {
        "ed25519": "zBdpQwWYyz1MkZuEUhXqcdMfUNN/B9psLFDDDTJOg64"
    },
-    "forwarding_curve25519_key_chain": []
+    "forwarding_curve25519_key_chain": [],
+    "org.matrix.msc3061.shared_history": true
 };

 /** A ratcheted version of BOB_MEGOLM_SESSION_DATA */
@@ -416,7 +413,7 @@ export const BOB_CURVE25519_KEY_BACKUP_DATA: KeyBackupSession = {
    "forwarded_count": 0,
    "is_verified": false,
    "session_data": {
-        "ciphertext": "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",
+        "ciphertext": "d7UVOK17WEVky/8hK0h3HsTQrFMEbKbfqMcl2KtyTWcI9S5gGFWK9Git5BzVRxRggvxQ0c8PDfqL+dr3zHytAA7TEpHlx8Ks23hCqXmVW710VjqK2K9xnWCyJvkHfE8x0w6AYvffDj+tRVP8C8M7t4849rD2itn0uma+YMkvjG/nANUTxG1dBf3oUOZ673vflCPoaz7s7x9ZNhYDVSVH5JTdMgNwwN42R5dqqxnGTu516tJzJh/9BWvyD9oIPWJ8X0rt1sbzEJ3PZeBXcSy8GTlZ1SgSFjeiXlwYxOZCaX2sxprk4N1oI1db6g+wCDBhbCGGucJIlTDJna/h9/C5J4drGd/fkisG3SidUmJXXCyInhs/BhwjGAtTGeQS8j7R8UnJxhMulYBHSckzj0Kas71LElPp8W8M4Jq81APA03n5UfYB+U6jbxjDgf8OJnxGQyrteq9F2+SEvS/TwHe1pE3t6EM2mDYRoYDTpU5pTNYSJkGIQMfWJKRxxuWUGs29o1twewJ6dhHgm+SlCII0M7ESoVdV54vxZCvHZnPcR0NXDzal7ils7zBKJmamHfPQBuaqNPU3KmSo+5R8ngFPaWU5LbWqYp/WxSBfNCoLZ7Jf8Io5uitjXTATR2qy2r6l/RJmk3RlfP51kliQqI2TWqRF96oaB96IGgUGSFCX/2pv0psOBGc1SjfmMB3d7gYis+2iBYVbG3xmnpeXbqvlD0Lw9TiTIPkjhJkTW1+lXyhy1xVH9ZmcFamcL7bX15Jx",
        "ephemeral": "oO0VX84OUIzm2i/12zAhTWOZT5IFRH5mXaKZ8fXkCgU",
        "mac": "lEfHlqfJQwU"
    }
@@ -449,6 +446,34 @@ export const BOB_ENCRYPTED_EVENT: Partial<IEvent> = {
    "origin_server_ts": 1507753886000
 };

+/** base64-encoded backup decryption (private) key */
+export const BOB_BACKUP_DECRYPTION_KEY_BASE64 = "DwdtCnMYpX08FsFyUbJmRd9ML4frwJkqsXf7pR25LCo=";
+
+/** Backup decryption key in export format */
+export const BOB_BACKUP_DECRYPTION_KEY_BASE58 = "EsT5 Sd5m mEXs NQYE ibRe 3q9E 4aXW rHih 5f9J 6rU6 AfwY mASR";
+
+/** Signed backup data, suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}/{sessionId}` */
+export const BOB_SIGNED_BACKUP_DATA: KeyBackupInfo = {
+    "algorithm": "m.megolm_backup.v1.curve25519-aes-sha2",
+    "version": "1",
+    "auth_data": {
+        "public_key": "ZRuVWcWlDuvOwZRygccUCD4Avtnt130800I+WQNwwRY",
+        "signatures": {
+            "@bob:xyz": {
+                "ed25519:bob_device": "lDIMj3VC0WazE2FamGHpmbiqKf9Z4pO4qapZ5TL5BnD3c+dvb+2waOEd6pgay/pmrQ6MW4Eu2KDEpe1fnHc3BA"
+            }
+        }
+    }
+};
+
+/**
+ * Per-room backup data, (supposedly) suitable for return from `GET /_matrix/client/v3/room_keys/keys/{roomId}`.
+ * Contains the key from BOB_MEGOLM_SESSION_DATA.
+ */
+export const BOB_PER_ROOM_CURVE25519_KEY_BACKUP_DATA: KeyBackupRoomSessions = {
+     [BOB_MEGOLM_SESSION_DATA.session_id]: BOB_CURVE25519_KEY_BACKUP_DATA
+};
+
 /** A second set of signed cross-signing keys data, also suitable for returning from a `/keys/query` call */
 export const BOB_ALT_SIGNED_CROSS_SIGNING_KEYS_DATA: Partial<IDownloadKeyResult> = {
    "master_keys": {
@@ -1,9 +1,7 @@
-// load olm before the sdk if possible
-import "../olm-loader";
+import mkdebug from "debug";

 // eslint-disable-next-line no-restricted-imports
 import type EventEmitter from "events";
-import { logger } from "../../src/logger";
 import {
    type IContent,
    type IEvent,
@@ -15,6 +13,7 @@ import {
 import {
    ClientEvent,
    EventType,
+    HistoryVisibility,
    type IJoinedRoom,
    type IPusher,
    type ISyncResponse,
@@ -27,6 +26,8 @@ import { eventMapperFor } from "../../src/event-mapper";
 import { TEST_ROOM_ID } from "./test-data";
 import { KnownMembership, type Membership } from "../../src/@types/membership";

+const debug = mkdebug("test-utils");
+
 /**
 * Return a promise that is resolved when the client next emits a
 * SYNCING event.
@@ -41,7 +42,7 @@ export function syncPromise(client: MatrixClient, count = 1): Promise<void> {

    const p = new Promise<void>((resolve) => {
        const cb = (state: SyncState) => {
-            logger.log(`${Date.now()} syncPromise(${count}): ${state}`);
+            debug(`syncPromise(${count}): ${state}`);
            if (state === SyncState.Syncing) {
                resolve();
            } else {
@@ -57,13 +58,22 @@ export function syncPromise(client: MatrixClient, count = 1): Promise<void> {
 }

 /**
- * Return a sync response which contains a single room (by default TEST_ROOM_ID), with the members given
- * @param roomMembers
- * @param roomId
+ * Return a sync response which contains a single room (by default `TEST_ROOM_ID`), with the members given
+ * and history visibility set to `shared`.
 *
- * @returns the sync response
+ * @param roomMembers - An array of user IDs representing the members of the room.
+ * @param roomHistoryVisibility - The history visibility setting for the room. Defaults to `shared`.
+ * @param roomId - The ID of the room. Defaults to `TEST_ROOM_ID`.
+ * @param encryptStateEvents - A boolean indicating whether state events should be encrypted. Defaults to `false`.
+ *
+ * @returns The sync response object containing the room data.
 */
-export function getSyncResponse(roomMembers: string[], roomId = TEST_ROOM_ID): ISyncResponse {
+export function getSyncResponse(
+    roomMembers: string[],
+    roomHistoryVisibility: HistoryVisibility = HistoryVisibility.Shared,
+    roomId = TEST_ROOM_ID,
+    encryptStateEvents = false,
+): ISyncResponse {
    const roomResponse: IJoinedRoom = {
        summary: {
            "m.heroes": [],
@@ -77,7 +87,16 @@ 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,
+                    },
+                }),
+                mkEventCustom({
+                    sender: roomMembers[0],
+                    type: "m.room.history_visibility",
+                    state_key: "",
+                    content: {
+                        history_visibility: roomHistoryVisibility,
                    },
                }),
            ],
@@ -131,7 +150,7 @@ export function mock<T>(constr: { new (...args: any[]): T }, name: string): T {
        // eslint-disable-line guard-for-in
        try {
            if (constr.prototype[key] instanceof Function) {
-                result[key] = jest.fn();
+                result[key] = vi.fn();
            }
        } catch {
            // Direct access to some non-function fields of DOM prototypes may
@@ -522,25 +541,25 @@ export async function awaitDecryption(
    // already
    if (event.getClearContent() !== null) {
        if (waitOnDecryptionFailure && event.isDecryptionFailure()) {
-            logger.log(`${Date.now()}: event ${event.getId()} got decryption error; waiting`);
+            debug(`event ${event.getId()} got decryption error; waiting`);
        } else {
            return event;
        }
    } else {
-        logger.log(`${Date.now()}: event ${event.getId()} is not yet decrypted; waiting`);
+        debug(`event ${event.getId()} is not yet decrypted; waiting`);
    }

    return new Promise((resolve) => {
        if (waitOnDecryptionFailure) {
            event.on(MatrixEventEvent.Decrypted, (ev, err) => {
-                logger.log(`${Date.now()}: MatrixEventEvent.Decrypted for event ${event.getId()}: ${err ?? "success"}`);
+                debug(`MatrixEventEvent.Decrypted for event ${event.getId()}: ${err ?? "success"}`);
                if (!err) {
                    resolve(ev);
                }
            });
        } else {
            event.once(MatrixEventEvent.Decrypted, (ev, err) => {
-                logger.log(`${Date.now()}: MatrixEventEvent.Decrypted for event ${event.getId()}: ${err ?? "success"}`);
+                debug(`MatrixEventEvent.Decrypted for event ${event.getId()}: ${err ?? "success"}`);
                resolve(ev);
            });
        }
@@ -587,8 +606,103 @@ export async function advanceTimersUntil<T>(promise: Promise<T>): Promise<T> {
    });

    while (!resolved) {
-        await jest.advanceTimersByTimeAsync(1);
+        await vi.advanceTimersByTimeAsync(1);
    }

    return await promise;
 }
+
+export function jestFakeTimersAreEnabled(): boolean {
+    return Object.prototype.hasOwnProperty.call(setTimeout, "clock");
+}
+
+/**
+ * Run `callback` in a loop, until it returns a successful result (i.e. it does not throw), or we reach a timeout
+ *
+ * Based on the function of the same name in the {@link https://testing-library.com/docs/dom-testing-library/api-async/#waitfor DOM testing library}.
+ *
+ * @param callback - The function to call to check if we can proceed. If it returns a result (including a falsey one),
+ *   `waitFor` returns that result. If it throws, `waitFor` continues to wait.
+ *
+ *   May return a promise, in which case no further checks are done until the promise resolves.
+ *
+ * @param timeout - The time to wait for, overall, in ms. If `callback` still hasn't returned a successful result after
+ *    this time, `waitFor` will throw an error.
+ *
+ *    Defaults to 1000.
+ *
+ * @param interval - How often to call `callback`. Defaults to 50.
+ */
+export function waitFor<T>(
+    callback: () => Promise<T> | T,
+    {
+        timeout = 1000,
+        interval = 50,
+    }: {
+        timeout?: number;
+        interval?: number;
+    } = {},
+): Promise<T> {
+    return new Promise((resolve, reject) => {
+        let lastError: any;
+        let finished = false;
+        let intervalId: ReturnType<typeof setTimeout> | undefined;
+        let promisePending = false;
+
+        const overallTimeoutTimer = setTimeout(handleTimeout, timeout);
+        const usingJestFakeTimers = jestFakeTimersAreEnabled();
+        if (usingJestFakeTimers) {
+            checkCallback();
+
+            while (!finished) {
+                vi.advanceTimersByTime(interval);
+
+                // Could have timed-out
+                if (finished) break;
+
+                checkCallback();
+            }
+        } else {
+            intervalId = setInterval(checkCallback, interval);
+            checkCallback();
+        }
+
+        function checkCallback() {
+            if (promisePending) {
+                // still waiting for the previous check
+                return;
+            }
+
+            async function doCheck() {
+                try {
+                    const result = await callback();
+                    onDone();
+                    resolve(result);
+                } catch (error) {
+                    // Save the most recent callback error to reject the promise with it in the event of a timeout
+                    lastError = error;
+                }
+            }
+
+            promisePending = true;
+            doCheck().finally(() => {
+                promisePending = false;
+            });
+        }
+
+        function onDone(): void {
+            finished = true;
+            clearTimeout(overallTimeoutTimer);
+            if (intervalId !== undefined) clearInterval(intervalId);
+        }
+
+        function handleTimeout() {
+            onDone();
+            if (lastError) {
+                reject(lastError);
+            } else {
+                reject(new Error("Timed out in waitFor."));
+            }
+        }
+    });
+}
@@ -17,21 +17,17 @@ limitations under the License.
 import {
    type ClientEvent,
    type ClientEventHandlerMap,
-    type EmptyObject,
    EventType,
    type GroupCall,
    GroupCallIntent,
    GroupCallType,
    type IContent,
-    type ISendEventResponse,
    type MatrixClient,
    type MatrixEvent,
-    type Room,
    RoomMember,
    type RoomState,
    RoomStateEvent,
    type RoomStateEventHandlerMap,
-    type SendToDeviceContentMap,
 } from "../../src";
 import { TypedEventEmitter } from "../../src/models/typed-event-emitter";
 import { ReEmitter } from "../../src/ReEmitter";
@@ -269,19 +265,20 @@ export class MockRTCRtpTransceiver {
        this.peerConn.needsNegotiation = true;
    }

-    public setCodecPreferences = jest.fn<void, RTCRtpCodec[]>();
+    public setCodecPreferences = vi.fn<RTCRtpTransceiver["setCodecPreferences"]>();
 }

-export class MockMediaStreamTrack {
+export class MockMediaStreamTrack extends EventTarget {
    constructor(
        public readonly id: string,
        public readonly kind: "audio" | "video",
        public enabled = true,
-    ) {}
+    ) {
+        super();
+    }

-    public stop = jest.fn<void, []>();
+    public stop = vi.fn<() => void>();

-    public listeners: [string, (...args: any[]) => any][] = [];
    public isStopped = false;
    public settings?: MediaTrackSettings;

@@ -289,45 +286,21 @@ export class MockMediaStreamTrack {
        return this.settings!;
    }

-    // XXX: Using EventTarget in jest doesn't seem to work, so we write our own
-    // implementation
-    public dispatchEvent(eventType: string) {
-        this.listeners.forEach(([t, c]) => {
-            if (t !== eventType) return;
-            c();
-        });
-    }
-    public addEventListener(eventType: string, callback: (...args: any[]) => any) {
-        this.listeners.push([eventType, callback]);
-    }
-    public removeEventListener(eventType: string, callback: (...args: any[]) => any) {
-        this.listeners.filter(([t, c]) => {
-            return t !== eventType || c !== callback;
-        });
-    }
-
    public typed(): MediaStreamTrack {
        return this as unknown as MediaStreamTrack;
    }
 }

-// XXX: Using EventTarget in jest doesn't seem to work, so we write our own
-// implementation
-export class MockMediaStream {
+export class MockMediaStream extends EventTarget {
    constructor(
        public id: string,
        private tracks: MockMediaStreamTrack[] = [],
-    ) {}
+    ) {
+        super();
+    }

-    public listeners: [string, (...args: any[]) => any][] = [];
    public isStopped = false;

-    public dispatchEvent(eventType: string) {
-        this.listeners.forEach(([t, c]) => {
-            if (t !== eventType) return;
-            c();
-        });
-    }
    public getTracks() {
        return this.tracks;
    }
@@ -337,17 +310,9 @@ export class MockMediaStream {
    public getVideoTracks() {
        return this.tracks.filter((track) => track.kind === "video");
    }
-    public addEventListener(eventType: string, callback: (...args: any[]) => any) {
-        this.listeners.push([eventType, callback]);
-    }
-    public removeEventListener(eventType: string, callback: (...args: any[]) => any) {
-        this.listeners.filter(([t, c]) => {
-            return t !== eventType || c !== callback;
-        });
-    }
    public addTrack(track: MockMediaStreamTrack) {
        this.tracks.push(track);
-        this.dispatchEvent("addtrack");
+        this.dispatchEvent(new Event("addtrack"));
    }
    public removeTrack(track: MockMediaStreamTrack) {
        this.tracks.splice(this.tracks.indexOf(track), 1);
@@ -391,7 +356,7 @@ export class MockMediaHandler {
    public stopUserMediaStream(stream: MockMediaStream) {
        stream.isStopped = true;
    }
-    public getScreensharingStream = jest.fn((opts?: IScreensharingOpts) => {
+    public getScreensharingStream = vi.fn((opts?: IScreensharingOpts) => {
        const tracks = [new MockMediaStreamTrack("screenshare_video_track", "video")];
        if (opts?.audio) tracks.push(new MockMediaStreamTrack("screenshare_audio_track", "audio"));

@@ -416,19 +381,19 @@ export class MockMediaHandler {
 }

 export class MockMediaDevices {
-    public enumerateDevices = jest
-        .fn<Promise<MediaDeviceInfo[]>, []>()
+    public enumerateDevices = vi
+        .fn<MediaDevices["enumerateDevices"]>()
        .mockResolvedValue([
            new MockMediaDeviceInfo("audioinput").typed(),
            new MockMediaDeviceInfo("videoinput").typed(),
        ]);

-    public getUserMedia = jest
-        .fn<Promise<MediaStream>, [MediaStreamConstraints]>()
+    public getUserMedia = vi
+        .fn<MediaDevices["getUserMedia"]>()
        .mockReturnValue(Promise.resolve(new MockMediaStream("local_stream").typed()));

-    public getDisplayMedia = jest
-        .fn<Promise<MediaStream>, [MediaStreamConstraints]>()
+    public getDisplayMedia = vi
+        .fn<MediaDevices["getDisplayMedia"]>()
        .mockReturnValue(Promise.resolve(new MockMediaStream("local_display_stream").typed()));

    public typed(): MediaDevices {
@@ -462,14 +427,8 @@ export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, Emitt
        calls: new Map<string, MatrixCall>(),
    };

-    public sendStateEvent = jest.fn<
-        Promise<ISendEventResponse>,
-        [roomId: string, eventType: EventType, content: any, statekey: string]
-    >();
-    public sendToDevice = jest.fn<
-        Promise<EmptyObject>,
-        [eventType: string, contentMap: SendToDeviceContentMap, txnId?: string]
-    >();
+    public sendStateEvent = vi.fn<MatrixClient["sendStateEvent"]>();
+    public sendToDevice = vi.fn<MatrixClient["sendToDevice"]>();

    public isInitialSyncComplete(): boolean {
        return false;
@@ -499,11 +458,11 @@ export class MockCallMatrixClient extends TypedEventEmitter<EmittedEvents, Emitt
    public getUseE2eForGroupCall = () => false;
    public checkTurnServers = () => null;

-    public getSyncState = jest.fn<SyncState | null, []>().mockReturnValue(SyncState.Syncing);
+    public getSyncState = vi.fn<MatrixClient["getSyncState"]>().mockReturnValue(SyncState.Syncing);

-    public getRooms = jest.fn<Room[], []>().mockReturnValue([]);
-    public getRoom = jest.fn();
-    public getFoci = jest.fn();
+    public getRooms = vi.fn<MatrixClient["getRooms"]>().mockReturnValue([]);
+    public getRoom = vi.fn();
+    public getFoci = vi.fn();

    public supportsThreads(): boolean {
        return true;
@@ -534,20 +493,20 @@ export class MockMatrixCall extends TypedEventEmitter<CallEvent, CallEventHandle
    public opponentMember = { userId: this.opponentUserId };
    public callId = "1";
    public localUsermediaFeed = {
-        setAudioVideoMuted: jest.fn<void, [boolean, boolean]>(),
-        isAudioMuted: jest.fn().mockReturnValue(false),
-        isVideoMuted: jest.fn().mockReturnValue(false),
+        setAudioVideoMuted: vi.fn<CallFeed["setAudioVideoMuted"]>(),
+        isAudioMuted: vi.fn().mockReturnValue(false),
+        isVideoMuted: vi.fn().mockReturnValue(false),
        stream: new MockMediaStream("stream"),
    } as unknown as CallFeed;
    public remoteUsermediaFeed?: CallFeed;
    public remoteScreensharingFeed?: CallFeed;

-    public reject = jest.fn<void, []>();
-    public answerWithCallFeeds = jest.fn<void, [CallFeed[]]>();
-    public hangup = jest.fn<void, []>();
-    public initStats = jest.fn<void, []>();
+    public reject = vi.fn<() => void>();
+    public answerWithCallFeeds = vi.fn<MatrixCall["answerWithCallFeeds"]>();
+    public hangup = vi.fn<() => void>();
+    public initStats = vi.fn<() => void>();

-    public sendMetadataUpdate = jest.fn<void, []>();
+    public sendMetadataUpdate = vi.fn<() => void>();

    public getOpponentMember(): Partial<RoomMember> {
        return this.opponentMember;
@@ -586,11 +545,11 @@ export class MockCallFeed {
 }

 export function installWebRTCMocks() {
-    globalThis.navigator = {
+    vi.stubGlobal("navigator", {
        mediaDevices: new MockMediaDevices().typed(),
-    } as unknown as Navigator;
+    });

-    globalThis.window = {
+    vi.stubGlobal("window", {
        // @ts-ignore Mock
        RTCPeerConnection: MockRTCPeerConnection,
        // @ts-ignore Mock
@@ -598,16 +557,16 @@ export function installWebRTCMocks() {
        // @ts-ignore Mock
        RTCIceCandidate: {},
        getUserMedia: () => new MockMediaStream("local_stream"),
-    };
-    // @ts-ignore Mock
-    globalThis.document = {};
+    });
+
+    vi.stubGlobal("document", {});

    // @ts-ignore Mock
    globalThis.AudioContext = MockAudioContext;

    // @ts-ignore Mock
    globalThis.RTCRtpReceiver = {
-        getCapabilities: jest.fn<RTCRtpCapabilities, [string]>().mockReturnValue({
+        getCapabilities: vi.fn().mockReturnValue({
            codecs: [],
            headerExtensions: [],
        }),
@@ -615,7 +574,7 @@ export function installWebRTCMocks() {

    // @ts-ignore Mock
    globalThis.RTCRtpSender = {
-        getCapabilities: jest.fn<RTCRtpCapabilities, [string]>().mockReturnValue({
+        getCapabilities: vi.fn().mockReturnValue({
            codecs: [],
            headerExtensions: [],
        }),
@@ -632,22 +591,22 @@ export function makeMockGroupCallStateEvent(
    redacted?: boolean,
 ): MatrixEvent {
    return {
-        getType: jest.fn().mockReturnValue(EventType.GroupCallPrefix),
-        getRoomId: jest.fn().mockReturnValue(roomId),
-        getTs: jest.fn().mockReturnValue(0),
-        getContent: jest.fn().mockReturnValue(content),
-        getStateKey: jest.fn().mockReturnValue(groupCallId),
-        isRedacted: jest.fn().mockReturnValue(redacted ?? false),
+        getType: vi.fn().mockReturnValue(EventType.GroupCallPrefix),
+        getRoomId: vi.fn().mockReturnValue(roomId),
+        getTs: vi.fn().mockReturnValue(0),
+        getContent: vi.fn().mockReturnValue(content),
+        getStateKey: vi.fn().mockReturnValue(groupCallId),
+        isRedacted: vi.fn().mockReturnValue(redacted ?? false),
    } as unknown as MatrixEvent;
 }

 export function makeMockGroupCallMemberStateEvent(roomId: string, groupCallId: string): MatrixEvent {
    return {
-        getType: jest.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
-        getRoomId: jest.fn().mockReturnValue(roomId),
-        getTs: jest.fn().mockReturnValue(0),
-        getContent: jest.fn().mockReturnValue({}),
-        getStateKey: jest.fn().mockReturnValue(groupCallId),
+        getType: vi.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
+        getRoomId: vi.fn().mockReturnValue(roomId),
+        getTs: vi.fn().mockReturnValue(0),
+        getContent: vi.fn().mockReturnValue({}),
+        getStateKey: vi.fn().mockReturnValue(groupCallId),
    } as unknown as MatrixEvent;
 }

@@ -32,7 +32,7 @@ describe("NamespacedValue", () => {
    });

    it("should have a falsey unstable if needed", () => {
-        const ns = new NamespacedValue("stable");
+        const ns = new NamespacedValue("stable", null);
        expect(ns.name).toBe(ns.stable);
        expect(ns.altName).toBeFalsy();
        expect(ns.names).toEqual([ns.stable]);
@@ -61,7 +61,7 @@ describe("UnstableValue", () => {
    it("should return unstable if there is no stable", () => {
        const ns = new UnstableValue(null!, "unstable");
        expect(ns.name).toBe(ns.unstable);
-        expect(ns.altName).toBeFalsy();
+        expect(<any>ns.altName).toBeFalsy();
        expect(ns.names).toEqual([ns.unstable]);
    });

@@ -38,7 +38,7 @@ describe("ReEmitter", function () {
        const src = new EventSource();
        const tgt = new EventTarget();

-        const handler = jest.fn();
+        const handler = vi.fn();
        tgt.on(EVENTNAME, handler);

        const reEmitter = new ReEmitter(tgt);
@@ -61,7 +61,7 @@ describe("ReEmitter", function () {
        // without the workaround in ReEmitter, this would throw
        src.doAnError();

-        const handler = jest.fn();
+        const handler = vi.fn();
        tgt.on("error", handler);

        src.doAnError();
@@ -5,6 +5,7 @@ import { getMockClientWithEventEmitter } from "../test-utils/client";
 import { StubStore } from "../../src/store/stub";
 import { type IndexedToDeviceBatch } from "../../src/models/ToDeviceMessage";
 import { SyncState } from "../../src/sync";
+import { logger } from "../../src/logger.ts";

 describe("onResumedSync", () => {
    let batch: IndexedToDeviceBatch | null;
@@ -34,16 +35,16 @@ describe("onResumedSync", () => {
        };

        store = new StubStore();
-        store.getOldestToDeviceBatch = jest.fn().mockImplementation(() => {
+        store.getOldestToDeviceBatch = vi.fn().mockImplementation(() => {
            return batch;
        });
-        store.removeToDeviceBatch = jest.fn().mockImplementation(() => {
+        store.removeToDeviceBatch = vi.fn().mockImplementation(() => {
            batch = null;
        });

        mockClient = getMockClientWithEventEmitter({});
        mockClient.store = store;
-        mockClient.sendToDevice = jest.fn().mockImplementation(async () => {
+        mockClient.sendToDevice = vi.fn().mockImplementation(async () => {
            if (shouldFailSendToDevice) {
                await Promise.reject(new ConnectionError("")).finally(() => {
                    setTimeout(onSendToDeviceFailure, 0);
@@ -55,7 +56,7 @@ describe("onResumedSync", () => {
            }
        });

-        queue = new ToDeviceMessageQueue(mockClient);
+        queue = new ToDeviceMessageQueue(mockClient, logger);
    });

    it("resends queue after connectivity restored", async () => {
@@ -35,6 +35,7 @@ describe("AutoDiscovery", function () {
        AutoDiscovery.setFetchFn(realAutoDiscoveryFetch);
    });

+    // eslint-disable-next-line @vitest/expect-expect
    it("should throw an error when no domain is specified", function () {
        getHttpBackend();
        return Promise.all([
@@ -190,7 +191,7 @@ describe("AutoDiscovery", function () {
        };
        return Promise.all([
            httpBackend.flushAllExpected(),
-            AutoDiscovery.findClientConfig("example.org").then(expect(expected).toEqual),
+            AutoDiscovery.findClientConfig("example.org").then((config) => expect(config).toEqual(expected)),
        ]);
    });

@@ -29,10 +29,10 @@ describe("Beacon content helpers", () => {
    describe("makeBeaconInfoContent()", () => {
        const mockDateNow = 123456789;
        beforeEach(() => {
-            jest.spyOn(globalThis.Date, "now").mockReturnValue(mockDateNow);
+            vi.spyOn(globalThis.Date, "now").mockReturnValue(mockDateNow);
        });
        afterAll(() => {
-            jest.spyOn(globalThis.Date, "now").mockRestore();
+            vi.spyOn(globalThis.Date, "now").mockRestore();
        });
        it("create fully defined event content", () => {
            expect(makeBeaconInfoContent(1234, true, "nice beacon_info", LocationAssetType.Pin)).toEqual({
@@ -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",
@@ -14,8 +14,11 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

+/**
+ * @vitest-environment happy-dom
+ */
+
 import "fake-indexeddb/auto";
-import "jest-localstorage-mock";
 import { IndexedDBCryptoStore, LocalStorageCryptoStore, MemoryCryptoStore } from "../../../../src";
 import { type CryptoStore, MigrationState, SESSION_BATCH_SIZE } from "../../../../src/crypto/store/base";

@@ -29,12 +29,7 @@ describe("sha256", () => {
    });

    it("throws if webcrypto is not available", async () => {
-        const oldCrypto = globalThis.crypto;
-        try {
-            globalThis.crypto = {} as any;
-            await expect(sha256("test")).rejects.toThrow();
-        } finally {
-            globalThis.crypto = oldCrypto;
-        }
+        vi.stubGlobal("crypto", {});
+        await expect(sha256("test")).rejects.toThrow();
    });
 });
@@ -1,7 +1,3 @@
-/**
- * @jest-environment jsdom
- */
-
 /*
 Copyright 2022 The Matrix.org Foundation C.I.C.

@@ -22,7 +18,7 @@ limitations under the License.
 // project, which doesn't know about our TypeEventEmitter implementation at all
 // eslint-disable-next-line no-restricted-imports
 import { EventEmitter } from "events";
-import { type MockedObject } from "jest-mock";
+import { type MockedObject } from "vitest";
 import {
    type WidgetApi,
    WidgetApiToWidgetAction,
@@ -36,7 +32,14 @@ import {
    type IRoomEvent,
 } from "matrix-widget-api";

-import { createRoomWidgetClient, MatrixError, MsgType, UpdateDelayedEventAction } from "../../src/matrix";
+import {
+    createRoomWidgetClient,
+    EventType,
+    type IEvent,
+    MatrixError,
+    MsgType,
+    UpdateDelayedEventAction,
+} from "../../src/matrix";
 import { MatrixClient, ClientEvent, type ITurnServer as IClientTurnServer } from "../../src/client";
 import { SyncState } from "../../src/sync";
 import { type ICapabilities, type RoomWidgetClient } from "../../src/embedded";
@@ -46,6 +49,7 @@ import { sleep } from "../../src/utils";
 import { SlidingSync } from "../../src/sliding-sync";
 import { logger } from "../../src/logger";
 import { flushPromises } from "../test-utils/flushPromises";
+import { RoomStickyEventsEvent, type RoomStickyEventsMap } from "../../src/models/room-sticky-events";

 const testOIDCToken = {
    access_token: "12345678",
@@ -53,27 +57,28 @@ const testOIDCToken = {
    matrix_server_name: "homeserver.oabc",
    token_type: "Bearer",
 };
+
 class MockWidgetApi extends EventEmitter {
-    public start = jest.fn().mockResolvedValue(undefined);
-    public getClientVersions = jest.fn();
-    public requestCapability = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilities = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityForRoomTimeline = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToSendEvent = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToReceiveEvent = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToSendMessage = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToReceiveMessage = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToSendState = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToReceiveState = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToSendToDevice = jest.fn().mockResolvedValue(undefined);
-    public requestCapabilityToReceiveToDevice = jest.fn().mockResolvedValue(undefined);
-    public sendRoomEvent = jest.fn(
+    public start = vi.fn().mockResolvedValue(undefined);
+    public getClientVersions = vi.fn();
+    public requestCapability = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilities = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityForRoomTimeline = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToSendEvent = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToReceiveEvent = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToSendMessage = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToReceiveMessage = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToSendState = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToReceiveState = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToSendToDevice = vi.fn().mockResolvedValue(undefined);
+    public requestCapabilityToReceiveToDevice = vi.fn().mockResolvedValue(undefined);
+    public sendRoomEvent = vi.fn(
        async (eventType: string, content: unknown, roomId?: string, delay?: number, parentDelayId?: string) =>
            delay === undefined && parentDelayId === undefined
                ? { event_id: `$${Math.random()}` }
                : { delay_id: `id-${Math.random()}` },
    );
-    public sendStateEvent = jest.fn(
+    public sendStateEvent = vi.fn(
        async (
            eventType: string,
            stateKey: string,
@@ -86,22 +91,24 @@ class MockWidgetApi extends EventEmitter {
                ? { event_id: `$${Math.random()}` }
                : { delay_id: `id-${Math.random()}` },
    );
-    public updateDelayedEvent = jest.fn().mockResolvedValue(undefined);
-    public sendToDevice = jest.fn().mockResolvedValue(undefined);
-    public requestOpenIDConnectToken = jest.fn(async () => {
+    public cancelScheduledDelayedEvent = vi.fn().mockResolvedValue(undefined);
+    public restartScheduledDelayedEvent = vi.fn().mockResolvedValue(undefined);
+    public sendScheduledDelayedEvent = vi.fn().mockResolvedValue(undefined);
+    public sendToDevice = vi.fn().mockResolvedValue(undefined);
+    public requestOpenIDConnectToken = vi.fn(async () => {
        return testOIDCToken;
        return new Promise<IOpenIDCredentials>(() => {
            return testOIDCToken;
        });
    });
-    public readStateEvents = jest.fn(async () => []);
-    public getTurnServers = jest.fn(async () => []);
-    public sendContentLoaded = jest.fn().mockResolvedValue(undefined);
+    public readStateEvents = vi.fn(async () => []);
+    public getTurnServers = vi.fn(async () => []);
+    public sendContentLoaded = vi.fn().mockResolvedValue(undefined);

    public transport = {
-        reply: jest.fn(),
-        send: jest.fn(),
-        sendComplete: jest.fn(),
+        reply: vi.fn(),
+        send: vi.fn(),
+        sendComplete: vi.fn(),
    };

    /**
@@ -169,6 +176,9 @@ describe("RoomWidgetClient", () => {
                "org.matrix.rageshake_request",
                { request_id: 123 },
                "!1:example.org",
+                undefined,
+                undefined,
+                undefined,
            );
        });

@@ -228,7 +238,7 @@ describe("RoomWidgetClient", () => {
                );
                expect(widgetApi.requestCapabilityForRoomTimeline).toHaveBeenCalledWith("!1:example.org");
                expect(widgetApi.requestCapabilityToReceiveEvent).toHaveBeenCalledWith("org.matrix.rageshake_request");
-                const injectSpy = jest.spyOn((client as any).syncApi, "injectRoomEvents");
+                const injectSpy = vi.spyOn((client as any).syncApi, "injectRoomEvents");
                const widgetSendEmitter = new EventEmitter();
                const widgetSendPromise = new Promise<void>((resolve) =>
                    widgetSendEmitter.once("send", () => resolve()),
@@ -355,10 +365,10 @@ describe("RoomWidgetClient", () => {

        it("handles widget errors with generic error data", async () => {
            const error = new Error("failed to send");
-            widgetApi.transport.send.mockRejectedValue(error);
+            vi.mocked(widgetApi.transport.send).mockRejectedValue(error);

            await makeClient({ sendEvent: ["org.matrix.rageshake_request"] });
-            widgetApi.sendRoomEvent.mockImplementation(widgetApi.transport.send);
+            widgetApi.sendRoomEvent.mockImplementation(widgetApi.transport.send as any);

            await expect(
                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 123 }),
@@ -381,22 +391,22 @@ describe("RoomWidgetClient", () => {
                    response: errorData,
                },
            });
-            const matrixError = new MatrixError(errorData, errorStatusCode, errorUrl);
+            const matrixError = new MatrixError(errorData, errorStatusCode, errorUrl, undefined, expect.any(Headers));

-            widgetApi.transport.send.mockRejectedValue(widgetError);
+            vi.mocked(widgetApi.transport.send).mockRejectedValue(widgetError);

            await makeClient({ sendEvent: ["org.matrix.rageshake_request"] });
-            widgetApi.sendRoomEvent.mockImplementation(widgetApi.transport.send);
+            widgetApi.sendRoomEvent.mockImplementation(widgetApi.transport.send as any);

            await expect(
                client.sendEvent("!1:example.org", "org.matrix.rageshake_request", { request_id: 123 }),
-            ).rejects.toThrow(matrixError);
+            ).rejects.toStrictEqual(matrixError);
        });
    });

    describe("delayed events", () => {
        describe("when supported", () => {
-            const doesServerSupportUnstableFeatureMock = jest.fn((feature) =>
+            const doesServerSupportUnstableFeatureMock = vi.fn((feature) =>
                Promise.resolve(feature === "org.matrix.msc4140"),
            );

@@ -424,6 +434,7 @@ describe("RoomWidgetClient", () => {
                    "!1:example.org",
                    2000,
                    undefined,
+                    undefined,
                );
            });

@@ -444,6 +455,7 @@ describe("RoomWidgetClient", () => {
                    "!1:example.org",
                    undefined,
                    parentDelayId,
+                    undefined,
                );
            });

@@ -531,21 +543,63 @@ 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");
            });
        });

        describe("when unsupported", () => {
+            const doesServerSupportUnstableFeatureMock = vi.fn().mockResolvedValue(false);
+
+            beforeAll(() => {
+                MatrixClient.prototype.doesServerSupportUnstableFeature = doesServerSupportUnstableFeatureMock;
+            });
+
+            afterAll(() => {
+                doesServerSupportUnstableFeatureMock.mockReset();
+            });
+
            it("fails to send delayed message events", async () => {
                await makeClient({ sendEvent: ["org.matrix.rageshake_request"] });
                await expect(
@@ -583,6 +637,13 @@ 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");
+                }
            });
        });
    });
@@ -729,7 +790,7 @@ describe("RoomWidgetClient", () => {

                const emittedEvent = new Promise<MatrixEvent>((resolve) => client.once(ClientEvent.Event, resolve));
                const emittedSync = new Promise<SyncState>((resolve) => client.once(ClientEvent.Sync, resolve));
-                const logSpy = jest.spyOn(logger, "error");
+                const logSpy = vi.spyOn(logger, "error");
                widgetApi.emit(
                    `action:${WidgetApiToWidgetAction.SendEvent}`,
                    new CustomEvent(`action:${WidgetApiToWidgetAction.SendEvent}`, { detail: { data: event } }),
@@ -808,6 +869,162 @@ describe("RoomWidgetClient", () => {
        });
    });

+    describe("sticky events", () => {
+        describe("when supported", () => {
+            const doesServerSupportUnstableFeatureMock = vi.fn((feature) =>
+                Promise.resolve(feature === "org.matrix.msc4354"),
+            );
+
+            beforeAll(() => {
+                MatrixClient.prototype.doesServerSupportUnstableFeature = doesServerSupportUnstableFeatureMock;
+            });
+
+            afterAll(() => {
+                doesServerSupportUnstableFeatureMock.mockReset();
+            });
+
+            it("requests capabilities when set", async () => {
+                await makeClient({ sendSticky: true, receiveSticky: true });
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4407SendStickyEvent);
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4407ReceiveStickyEvent);
+            });
+
+            it("does not request capabilities when unset", async () => {
+                await makeClient({});
+                expect(widgetApi.requestCapability).not.toHaveBeenCalledWith(MatrixCapabilities.MSC4407SendStickyEvent);
+                expect(widgetApi.requestCapability).not.toHaveBeenCalledWith(
+                    MatrixCapabilities.MSC4407ReceiveStickyEvent,
+                );
+            });
+
+            it("sends", async () => {
+                await makeClient({ sendEvent: [EventType.RTCMembership], sendSticky: true });
+                expect(widgetApi.requestCapabilityForRoomTimeline).toHaveBeenCalledWith("!1:example.org");
+                expect(widgetApi.requestCapabilityToSendEvent).toHaveBeenCalledWith(EventType.RTCMembership);
+                expect(widgetApi.requestCapability).toHaveBeenCalledWith(MatrixCapabilities.MSC4407SendStickyEvent);
+                await client._unstable_sendStickyEvent("!1:example.org", 2000, null, EventType.RTCMembership, {
+                    msc4354_sticky_key: "test",
+                });
+                expect(widgetApi.sendRoomEvent).toHaveBeenCalledWith(
+                    EventType.RTCMembership,
+                    { msc4354_sticky_key: "test" },
+                    "!1:example.org",
+                    undefined,
+                    undefined,
+                    2000,
+                );
+            });
+
+            it("receives (adds, updates, then removes when redacted)", async () => {
+                await makeClient({ receiveEvent: [EventType.RTCMembership, EventType.RoomRedaction] });
+                const room = client.getRoom("!1:example.org")!;
+
+                function expectStickyEvents(events: IEvent[]) {
+                    expect([...room._unstable_getStickyEvents()].map((e) => e.getEffectiveEvent())).toEqual(events);
+                }
+
+                async function sendAndExpectStickyUpdate(
+                    eventToSend: IEvent,
+                    added: IEvent[],
+                    updated: { current: IEvent; previous: IEvent }[],
+                    removed: IEvent[],
+                ) {
+                    const emittedStickyUpdate = new Promise<
+                        Parameters<RoomStickyEventsMap[RoomStickyEventsEvent.Update]>
+                    >((resolve) => room.once(RoomStickyEventsEvent.Update, (...args) => resolve(args)));
+
+                    widgetApi.emit(
+                        `action:${WidgetApiToWidgetAction.SendEvent}`,
+                        new CustomEvent(`action:${WidgetApiToWidgetAction.SendEvent}`, {
+                            detail: { data: eventToSend },
+                        }),
+                    );
+
+                    const [addedReceived, updatedReceived, removedReceived] = await emittedStickyUpdate;
+                    expect(addedReceived.map((e) => e.getEffectiveEvent())).toEqual(added);
+                    expect(
+                        updatedReceived.map(({ current, previous }) => ({
+                            current: current.getEffectiveEvent(),
+                            previous: previous.getEffectiveEvent(),
+                        })),
+                    ).toEqual(updated);
+                    expect(removedReceived.map((e) => e.getEffectiveEvent())).toEqual(removed);
+                }
+
+                // First, add a new sticky event to the map. The client should emit.
+                const event1 = new MatrixEvent({
+                    type: EventType.RTCMembership,
+                    event_id: "$pduhfiidph",
+                    room_id: "!1:example.org",
+                    sender: "@alice:example.org",
+                    msc4354_sticky: { duration_ms: 1200000 },
+                    content: { msc4354_sticky_key: "test" },
+                }).getEffectiveEvent();
+                await sendAndExpectStickyUpdate(event1, [event1], [], []);
+                // It should remain cached in the sticky map
+                expectStickyEvents([event1]);
+
+                // Next, update the same key in the sticky map
+                const event2 = new MatrixEvent({
+                    type: EventType.RTCMembership,
+                    event_id: "$zshgyutptfh",
+                    room_id: "!1:example.org",
+                    sender: "@alice:example.org",
+                    msc4354_sticky: { duration_ms: 1200000 },
+                    content: { msc4354_sticky_key: "test" },
+                }).getEffectiveEvent();
+                await sendAndExpectStickyUpdate(event2, [], [{ current: event2, previous: event1 }], []);
+                expectStickyEvents([event2]);
+
+                // Next, redact the second event. Because it has the first as a predecessor, the map should revert to
+                // the first event.
+                const redaction1 = new MatrixEvent({
+                    type: EventType.RoomRedaction,
+                    event_id: "$cimoexnvz",
+                    room_id: "!1:example.org",
+                    sender: "@alice:example.org",
+                    redacts: event2.event_id,
+                    content: { redacts: event2.event_id },
+                }).getEffectiveEvent();
+                await sendAndExpectStickyUpdate(redaction1, [], [{ current: event1, previous: event2 }], []);
+                expectStickyEvents([event1]);
+
+                // Finally, redact the first event. Now everything should be gone from the map.
+                const redaction2 = new MatrixEvent({
+                    type: EventType.RoomRedaction,
+                    event_id: "$drgzmenlh",
+                    room_id: "!1:example.org",
+                    sender: "@alice:example.org",
+                    redacts: event1.event_id,
+                    content: { redacts: event1.event_id },
+                }).getEffectiveEvent();
+                await sendAndExpectStickyUpdate(redaction2, [], [], [event1]);
+                expectStickyEvents([]);
+            });
+        });
+
+        describe("when unsupported", () => {
+            const doesServerSupportUnstableFeatureMock = vi.fn().mockResolvedValue(false);
+
+            beforeAll(() => {
+                MatrixClient.prototype.doesServerSupportUnstableFeature = doesServerSupportUnstableFeatureMock;
+            });
+
+            afterAll(() => {
+                doesServerSupportUnstableFeatureMock.mockReset();
+            });
+
+            it("fails to send", async () => {
+                await makeClient({ sendEvent: [EventType.RTCMembership], sendSticky: true });
+                await expect(
+                    client._unstable_sendStickyEvent("!1:example.org", 2000, null, EventType.RTCMembership, {
+                        msc4354_sticky_key: "test",
+                    }),
+                ).rejects.toThrow("Server does not support");
+            });
+        });
+    });
+
    describe("to-device messages", () => {
        const unencryptedContentMap = new Map([
            ["@alice:example.org", new Map([["*", { hello: "alice!" }]])],
@@ -929,7 +1146,7 @@ describe("RoomWidgetClient", () => {

        it("handles widget errors with generic error data", async () => {
            const error = new Error("failed to get token");
-            widgetApi.transport.sendComplete.mockRejectedValue(error);
+            vi.mocked(widgetApi.transport.sendComplete).mockRejectedValue(error);

            await makeClient({});
            widgetApi.requestOpenIDConnectToken.mockImplementation(widgetApi.transport.sendComplete as any);
@@ -953,9 +1170,9 @@ describe("RoomWidgetClient", () => {
                    response: errorData,
                },
            });
-            const matrixError = new MatrixError(errorData, errorStatusCode, errorUrl);
+            const matrixError = new MatrixError(errorData, errorStatusCode, errorUrl, undefined, expect.any(Headers));

-            widgetApi.transport.sendComplete.mockRejectedValue(widgetError);
+            vi.mocked(widgetApi.transport.sendComplete).mockRejectedValue(widgetError);

            await makeClient({});
            widgetApi.requestOpenIDConnectToken.mockImplementation(widgetApi.transport.sendComplete as any);
@@ -37,7 +37,7 @@ describe("eventMapperFor", function () {
                setUserCreator(_) {},
            } as IStore,
            scheduler: {
-                setProcessFunction: jest.fn(),
+                setProcessFunction: vi.fn(),
            } as unknown as MatrixScheduler,
            userId: userId,
        });
@@ -133,7 +133,7 @@ describe("eventMapperFor", function () {
            event_id: eventId,
        };

-        const decryptEventIfNeededSpy = jest.spyOn(client, "decryptEventIfNeeded");
+        const decryptEventIfNeededSpy = vi.spyOn(client, "decryptEventIfNeeded");
        decryptEventIfNeededSpy.mockResolvedValue(); // stub it out

        const mapper = eventMapperFor(client, {
@@ -161,7 +161,7 @@ describe("eventMapperFor", function () {
            event_id: eventId,
        };

-        const evListener = jest.fn();
+        const evListener = vi.fn();
        client.on(MatrixEventEvent.Replaced, evListener);

        const noReEmitMapper = eventMapperFor(client, {
@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { mocked } from "jest-mock";
+import { type MockInstance } from "vitest";

 import * as utils from "../test-utils/test-utils";
 import {
@@ -196,7 +196,7 @@ describe("EventTimelineSet", () => {

        it("should aggregate relations which belong to unknown timeline without adding them to any timeline", () => {
            // If threads are disabled all events go into the main timeline
-            mocked(client.supportsThreads).mockReturnValue(true);
+            vi.mocked(client.supportsThreads).mockReturnValue(true);
            const reactionEvent = utils.mkReaction(messageEvent, client, client.getSafeUserId(), roomId);

            const liveTimeline = eventTimelineSet.getLiveTimeline();
@@ -228,7 +228,7 @@ describe("EventTimelineSet", () => {
        let thread: Thread;

        beforeEach(() => {
-            (client.supportsThreads as jest.Mock).mockReturnValue(true);
+            vi.mocked(client.supportsThreads).mockReturnValue(true);
            thread = new Thread("!thread_id:server", messageEvent, { room, client });
        });

@@ -306,20 +306,20 @@ describe("EventTimelineSet", () => {
        });

        describe("with events to be decrypted", () => {
-            let messageEventShouldAttemptDecryptionSpy: jest.SpyInstance;
-            let messageEventIsDecryptionFailureSpy: jest.SpyInstance;
+            let messageEventShouldAttemptDecryptionSpy: MockInstance;
+            let messageEventIsDecryptionFailureSpy: MockInstance;

-            let replyEventShouldAttemptDecryptionSpy: jest.SpyInstance;
-            let replyEventIsDecryptionFailureSpy: jest.SpyInstance;
+            let replyEventShouldAttemptDecryptionSpy: MockInstance;
+            let replyEventIsDecryptionFailureSpy: MockInstance;

            beforeEach(() => {
-                messageEventShouldAttemptDecryptionSpy = jest.spyOn(messageEvent, "shouldAttemptDecryption");
+                messageEventShouldAttemptDecryptionSpy = vi.spyOn(messageEvent, "shouldAttemptDecryption");
                messageEventShouldAttemptDecryptionSpy.mockReturnValue(true);
-                messageEventIsDecryptionFailureSpy = jest.spyOn(messageEvent, "isDecryptionFailure");
+                messageEventIsDecryptionFailureSpy = vi.spyOn(messageEvent, "isDecryptionFailure");

-                replyEventShouldAttemptDecryptionSpy = jest.spyOn(replyEvent, "shouldAttemptDecryption");
+                replyEventShouldAttemptDecryptionSpy = vi.spyOn(replyEvent, "shouldAttemptDecryption");
                replyEventShouldAttemptDecryptionSpy.mockReturnValue(true);
-                replyEventIsDecryptionFailureSpy = jest.spyOn(messageEvent, "isDecryptionFailure");
+                replyEventIsDecryptionFailureSpy = vi.spyOn(messageEvent, "isDecryptionFailure");

                eventTimelineSet.addEventsToTimeline([messageEvent, replyEvent], true, false, eventTimeline, "foo");
            });
@@ -384,7 +384,7 @@ describe("EventTimelineSet", () => {
        let thread: Thread;

        beforeEach(() => {
-            (client.supportsThreads as jest.Mock).mockReturnValue(true);
+            vi.mocked(client.supportsThreads).mockReturnValue(true);
            thread = new Thread("!thread_id:server", messageEvent, { room, client });
        });

@@ -1,5 +1,3 @@
-import { mocked } from "jest-mock";
-
 import * as utils from "../test-utils/test-utils";
 import { Direction, EventTimeline } from "../../src/models/event-timeline";
 import { RoomState } from "../../src/models/room-state";
@@ -20,21 +18,21 @@ describe("EventTimeline", function () {
    const getTimeline = (): EventTimeline => {
        const room = new Room(roomId, mockClient, userA);
        const timelineSet = new EventTimelineSet(room);
-        jest.spyOn(room, "getUnfilteredTimelineSet").mockReturnValue(timelineSet);
+        vi.spyOn(room, "getUnfilteredTimelineSet").mockReturnValue(timelineSet);

        const timeline = new EventTimeline(timelineSet);
        // We manually stub the methods we'll be mocking out later instead of mocking the whole module
        // otherwise the default member property values (e.g. paginationToken) will be incorrect
-        timeline.getState(Direction.Backward)!.setStateEvents = jest.fn();
-        timeline.getState(Direction.Backward)!.getSentinelMember = jest.fn();
-        timeline.getState(Direction.Forward)!.setStateEvents = jest.fn();
-        timeline.getState(Direction.Forward)!.getSentinelMember = jest.fn();
+        timeline.getState(Direction.Backward)!.setStateEvents = vi.fn();
+        timeline.getState(Direction.Backward)!.getSentinelMember = vi.fn();
+        timeline.getState(Direction.Forward)!.setStateEvents = vi.fn();
+        timeline.getState(Direction.Forward)!.getSentinelMember = vi.fn();
        return timeline;
    };

    beforeEach(function () {
        // reset any RoomState mocks
-        jest.resetAllMocks();
+        vi.resetAllMocks();

        timeline = getTimeline();
    });
@@ -67,12 +65,12 @@ describe("EventTimeline", function () {
            timeline.initialiseState(events);
            // @ts-ignore private prop
            const timelineStartState = timeline.startState!;
-            expect(mocked(timelineStartState).setStateEvents).toHaveBeenCalledWith(events, {
+            expect(vi.mocked(timelineStartState).setStateEvents).toHaveBeenCalledWith(events, {
                timelineWasEmpty: undefined,
            });
            // @ts-ignore private prop
            const timelineEndState = timeline.endState!;
-            expect(mocked(timelineEndState).setStateEvents).toHaveBeenCalledWith(events, {
+            expect(vi.mocked(timelineEndState).setStateEvents).toHaveBeenCalledWith(events, {
                timelineWasEmpty: undefined,
            });
        });
@@ -210,13 +208,13 @@ describe("EventTimeline", function () {
            sentinel.name = "Old Alice";
            sentinel.membership = KnownMembership.Join;

-            mocked(timeline.getState(EventTimeline.FORWARDS)!).getSentinelMember.mockImplementation(function (uid) {
+            vi.mocked(timeline.getState(EventTimeline.FORWARDS)!).getSentinelMember.mockImplementation(function (uid) {
                if (uid === userA) {
                    return sentinel;
                }
                return null;
            });
-            mocked(timeline.getState(EventTimeline.BACKWARDS)!).getSentinelMember.mockImplementation(function (uid) {
+            vi.mocked(timeline.getState(EventTimeline.BACKWARDS)!).getSentinelMember.mockImplementation(function (uid) {
                if (uid === userA) {
                    return oldSentinel;
                }
@@ -253,13 +251,13 @@ describe("EventTimeline", function () {
            sentinel.name = "Old Alice";
            sentinel.membership = KnownMembership.Join;

-            mocked(timeline.getState(EventTimeline.FORWARDS)!).getSentinelMember.mockImplementation(function (uid) {
+            vi.mocked(timeline.getState(EventTimeline.FORWARDS)!).getSentinelMember.mockImplementation(function (uid) {
                if (uid === userA) {
                    return sentinel;
                }
                return null;
            });
-            mocked(timeline.getState(EventTimeline.BACKWARDS)!).getSentinelMember.mockImplementation(function (uid) {
+            vi.mocked(timeline.getState(EventTimeline.BACKWARDS)!).getSentinelMember.mockImplementation(function (uid) {
                if (uid === userA) {
                    return oldSentinel;
                }
@@ -1,6 +1,6 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html

-exports[`MatrixHttpApi should return expected object from \`getContentUri\` 1`] = `
+exports[`MatrixHttpApi > should return expected object from \`getContentUri\` 1`] = `
 {
  "base": "http://baseUrl",
  "params": {
@@ -57,7 +57,7 @@ describe("MatrixError", () => {

    it("should retrieve Date Retry-After header from rate-limit error", () => {
        headers.set("Retry-After", `${new Date(160000).toUTCString()}`);
-        jest.spyOn(globalThis.Date, "now").mockImplementationOnce(() => 100000);
+        vi.spyOn(globalThis.Date, "now").mockImplementationOnce(() => 100000);
        const err = makeMatrixError(429, { errcode: "M_LIMIT_EXCEEDED", retry_after_ms: 150000 });
        expect(err.isRateLimitError()).toBe(true);
        // prefer Retry-After header over retry_after_ms
@@ -14,7 +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, type MockedFunction } from "vitest";

 import { FetchHttpApi } from "../../../src/http-api/fetch";
 import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";
@@ -27,6 +27,7 @@ import {
    type IHttpOpts,
    MatrixError,
    Method,
+    TokenRefreshError,
 } from "../../../src";
 import { emitPromise } from "../../test-utils/test-utils";
 import { type QueryDict, sleep } from "../../../src/utils";
@@ -39,42 +40,42 @@ describe("FetchHttpApi", () => {
    const tokenInactiveError = new MatrixError({ errcode: "M_UNKNOWN_TOKEN", error: "Token is not active" }, 401);

    beforeEach(() => {
-        jest.useRealTimers();
+        vi.useRealTimers();
    });

    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");
-        expect(fetchFn.mock.calls[0][0].href.endsWith("/foo")).toBeTruthy();
-        expect(fetchFn.mock.calls[0][1].signal.aborted).toBeFalsy();
-        expect(fetchFn.mock.calls[1][0].href.endsWith("/baz")).toBeTruthy();
-        expect(fetchFn.mock.calls[1][1].signal.aborted).toBeFalsy();
+        expect((fetchFn.mock.calls[0][0] as URL).href.endsWith("/foo")).toBeTruthy();
+        expect(fetchFn.mock.calls[0][1]?.signal?.aborted).toBeFalsy();
+        expect((fetchFn.mock.calls[1][0] as URL).href.endsWith("/baz")).toBeTruthy();
+        expect(fetchFn.mock.calls[1][1]?.signal?.aborted).toBeFalsy();

        api.abort();
-        expect(fetchFn.mock.calls[0][1].signal.aborted).toBeTruthy();
-        expect(fetchFn.mock.calls[1][1].signal.aborted).toBeTruthy();
+        expect(fetchFn.mock.calls[0][1]?.signal?.aborted).toBeTruthy();
+        expect(fetchFn.mock.calls[1][1]?.signal?.aborted).toBeTruthy();

        api.request(Method.Get, "/bar");
-        expect(fetchFn.mock.calls[2][0].href.endsWith("/bar")).toBeTruthy();
-        expect(fetchFn.mock.calls[2][1].signal.aborted).toBeFalsy();
+        expect((fetchFn.mock.calls[2][0] as URL).href.endsWith("/bar")).toBeTruthy();
+        expect(fetchFn.mock.calls[2][1]?.signal?.aborted).toBeFalsy();

        api.abort();
-        expect(fetchFn.mock.calls[2][1].signal.aborted).toBeTruthy();
+        expect(fetchFn.mock.calls[2][1]?.signal?.aborted).toBeTruthy();
    });

    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 spy = (globalThis.fetch = vi.fn());
+        expect(spy).not.toHaveBeenCalled();
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
        api.fetch("test");
-        expect(globalThis.fetch).toHaveBeenCalled();
+        expect(spy).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");
@@ -82,153 +83,213 @@ 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"]);
+            expect((fetchFn.mock.calls[0][0] as URL).searchParams.get("foo")).toBe("bar");
+            expect((fetchFn.mock.calls[0][0] as URL).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");
-            expect(JSON.parse(fetchFn.mock.calls[0][1].body)).toStrictEqual(params);
+            expect((fetchFn.mock.calls[0][0] as URL).searchParams.get("foo")).not.toBe("bar");
+            expect(JSON.parse(fetchFn.mock.calls[0][1]!.body as string)).toStrictEqual(params);
        });

        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");
+            expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>).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 return text if json=false", async () => {
+    it("should set an Accept header, and parse the response as JSON, by default", async () => {
+        const result = { a: 1 };
+        const fetchFn = vi.fn().mockResolvedValue({ ok: true, json: vi.fn().mockResolvedValue(result) });
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
+        await expect(api.requestOtherUrl(Method.Get, "http://url")).resolves.toBe(result);
+        expect(fetchFn.mock.calls[0][1].headers.Accept).toBe("application/json");
+    });
+
+    it("should not set an Accept header, and should return text if json=false", async () => {
        const text = "418 I'm a teapot";
-        const fetchFn = jest.fn().mockResolvedValue({ ok: true, text: jest.fn().mockResolvedValue(text) });
+        const fetchFn = vi.fn().mockResolvedValue({ ok: true, text: vi.fn().mockResolvedValue(text) });
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
        await expect(
            api.requestOtherUrl(Method.Get, "http://url", undefined, {
                json: false,
            }),
        ).resolves.toBe(text);
+        expect(fetchFn.mock.calls[0][1].headers.Accept).not.toBeDefined();
+    });
+
+    it("should not set an Accept header, and should return a blob, if rawResponseBody is true", async () => {
+        const blob = new Blob(["blobby"]);
+        const fetchFn = vi.fn().mockResolvedValue({ ok: true, blob: vi.fn().mockResolvedValue(blob) });
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
+        await expect(
+            api.requestOtherUrl(Method.Get, "http://url", undefined, {
+                rawResponseBody: true,
+            }),
+        ).resolves.toBe(blob);
+        expect(fetchFn.mock.calls[0][1].headers.Accept).not.toBeDefined();
+    });
+
+    it("should throw an error if both `json` and `rawResponseBody` are defined", async () => {
+        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
+            baseUrl,
+            prefix,
+            fetchFn: vi.fn(),
+            onlyData: true,
+        });
+        await expect(
+            api.requestOtherUrl(Method.Get, "http://url", undefined, { rawResponseBody: false, json: true }),
+        ).rejects.toThrow("Invalid call to `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");
+        expect((fetchFn.mock.calls[0][0] as URL).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");
+        expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>)["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();
-        expect(fetchFn.mock.calls[0][1].headers["Authorization"]).toBeFalsy();
+        expect((fetchFn.mock.calls[0][0] as URL).searchParams.get("access_token")).toBeFalsy();
+        expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>)["Authorization"]).toBeFalsy();
    });

    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();
-        expect(fetchFn.mock.calls[0][1].headers["Authorization"]).toBe("Bearer token");
+        expect((fetchFn.mock.calls[0][0] as URL).searchParams.get("access_token")).toBeFalsy();
+        expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>)["Authorization"]).toBe("Bearer token");
    });

    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");
+        expect((fetchFn.mock.calls[0][0] as URL).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" },
        });
-        expect(fetchFn.mock.calls[0][1].headers["Authorization"]).toBe("Bearer RealToken");
+        expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>)["Authorization"]).toBe("Bearer RealToken");
    });

    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" },
        });
-        expect(fetchFn.mock.calls[0][1].headers["Accept"]).toBe("text/html");
+        expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>)["Accept"]).toBe("text/html");
    });

    it("should emit NoConsent when given errcode=M_CONTENT_NOT_GIVEN", async () => {
-        const fetchFn = jest.fn().mockResolvedValue({
+        const fetchFn = vi.fn().mockResolvedValue({
            ok: false,
            headers: {
                get(name: string): string | null {
                    return name === "Content-Type" ? "application/json" : null;
                },
            },
-            text: jest.fn().mockResolvedValue(
+            text: vi.fn().mockResolvedValue(
                JSON.stringify({
                    errcode: "M_CONSENT_NOT_GIVEN",
                    error: "Ye shall ask for consent",
@@ -236,7 +297,7 @@ 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),
@@ -246,11 +307,11 @@ 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();
+            expect((fetchFn.mock.calls[0][1]!.headers as Record<string, any>).Authorization).toBeUndefined();
        });

        describe("with refresh token", () => {
@@ -263,7 +324,13 @@ describe("FetchHttpApi", () => {
                    error: "Token is not active",
                    soft_logout: false,
                };
-                const unknownTokenErr = new MatrixError(unknownTokenErrBody, 401);
+                const unknownTokenErr = new MatrixError(
+                    unknownTokenErrBody,
+                    401,
+                    undefined,
+                    undefined,
+                    expect.anything(),
+                );
                const unknownTokenResponse = {
                    ok: false,
                    status: 401,
@@ -272,19 +339,27 @@ describe("FetchHttpApi", () => {
                            return name === "Content-Type" ? "application/json" : null;
                        },
                    },
-                    text: jest.fn().mockResolvedValue(JSON.stringify(unknownTokenErrBody)),
+                    text: vi.fn().mockResolvedValue(JSON.stringify(unknownTokenErrBody)),
                };
                const okayResponse = {
                    ok: true,
                    status: 200,
+                    json: vi.fn().mockResolvedValue({ x: 1 }),
                };

                describe("without a tokenRefreshFunction", () => {
                    it("should emit logout and throw", async () => {
-                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
+                        const fetchFn = vi.fn().mockResolvedValue(unknownTokenResponse);
                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
-                        const api = new FetchHttpApi(emitter, { baseUrl, prefix, fetchFn, accessToken, refreshToken });
+                        vi.spyOn(emitter, "emit");
+                        const api = new FetchHttpApi(emitter, {
+                            baseUrl,
+                            prefix,
+                            fetchFn,
+                            accessToken,
+                            refreshToken,
+                            onlyData: true,
+                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
                            unknownTokenErr,
                        );
@@ -295,10 +370,10 @@ describe("FetchHttpApi", () => {
                describe("with a tokenRefreshFunction", () => {
                    it("should emit logout and throw when token refresh fails", async () => {
                        const error = new MatrixError();
-                        const tokenRefreshFunction = jest.fn().mockRejectedValue(error);
-                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
+                        const tokenRefreshFunction = vi.fn().mockRejectedValue(error);
+                        const fetchFn = vi.fn().mockResolvedValue(unknownTokenResponse);
                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
+                        vi.spyOn(emitter, "emit");
                        const api = new FetchHttpApi(emitter, {
                            baseUrl,
                            prefix,
@@ -306,6 +381,7 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            refreshToken,
+                            onlyData: true,
                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
                            unknownTokenErr,
@@ -316,10 +392,10 @@ describe("FetchHttpApi", () => {

                    it("should not emit logout but still throw when token refresh fails due to transitive fault", async () => {
                        const error = new ConnectionError("transitive fault");
-                        const tokenRefreshFunction = jest.fn().mockRejectedValue(error);
-                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
+                        const tokenRefreshFunction = vi.fn().mockRejectedValue(error);
+                        const fetchFn = vi.fn().mockResolvedValue(unknownTokenResponse);
                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
+                        vi.spyOn(emitter, "emit");
                        const api = new FetchHttpApi(emitter, {
                            baseUrl,
                            prefix,
@@ -327,9 +403,10 @@ describe("FetchHttpApi", () => {
                            tokenRefreshFunction,
                            accessToken,
                            refreshToken,
+                            onlyData: true,
                        });
                        await expect(api.authedRequest(Method.Post, "/account/password")).rejects.toThrow(
-                            unknownTokenErr,
+                            new TokenRefreshError(unknownTokenErr),
                        );
                        expect(tokenRefreshFunction).toHaveBeenCalledWith(refreshToken);
                        expect(emitter.emit).not.toHaveBeenCalledWith(HttpApiEvent.SessionLoggedOut, unknownTokenErr);
@@ -338,16 +415,16 @@ describe("FetchHttpApi", () => {
                    it("should refresh token and retry request", async () => {
                        const newAccessToken = "new-access-token";
                        const newRefreshToken = "new-refresh-token";
-                        const tokenRefreshFunction = jest.fn().mockResolvedValue({
+                        const tokenRefreshFunction = vi.fn().mockResolvedValue({
                            accessToken: newAccessToken,
                            refreshToken: newRefreshToken,
                        });
-                        const fetchFn = jest
+                        const fetchFn = vi
                            .fn()
                            .mockResolvedValueOnce(unknownTokenResponse)
                            .mockResolvedValueOnce(okayResponse);
                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
+                        vi.spyOn(emitter, "emit");
                        const api = new FetchHttpApi(emitter, {
                            baseUrl,
                            prefix,
@@ -355,11 +432,12 @@ 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);
@@ -378,7 +456,7 @@ describe("FetchHttpApi", () => {
                        // count because it's only to get a token with an expiry)
                        const newAccessToken = "new-access-token";
                        const newRefreshToken = "new-refresh-token";
-                        const tokenRefreshFunction = jest.fn().mockReturnValue({
+                        const tokenRefreshFunction = vi.fn().mockReturnValue({
                            accessToken: newAccessToken,
                            refreshToken: newRefreshToken,
                            // This needs to be sufficiently high that it's over the threshold for
@@ -387,10 +465,10 @@ describe("FetchHttpApi", () => {
                        });

                        // fetch doesn't like our new or old tokens
-                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
+                        const fetchFn = vi.fn().mockResolvedValue(unknownTokenResponse);

                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
+                        vi.spyOn(emitter, "emit");
                        const api = new FetchHttpApi(emitter, {
                            baseUrl,
                            prefix,
@@ -398,8 +476,9 @@ 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.toThrowError(
                            unknownTokenErr,
                        );

@@ -421,7 +500,7 @@ describe("FetchHttpApi", () => {

                        // first refresh is to get a token with an expiry at all, because we
                        // can't specify an expiry on the token we inject
-                        const tokenRefreshFunction = jest.fn().mockResolvedValueOnce({
+                        const tokenRefreshFunction = vi.fn().mockResolvedValueOnce({
                            accessToken: newAccessToken,
                            refreshToken: newRefreshToken,
                            expiry: new Date(Date.now() + 1000),
@@ -442,10 +521,10 @@ describe("FetchHttpApi", () => {
                            expiry: new Date(Date.now() + 5 * 60 * 1000),
                        });

-                        const fetchFn = jest.fn().mockResolvedValue(unknownTokenResponse);
+                        const fetchFn = vi.fn().mockResolvedValue(unknownTokenResponse);

                        const emitter = new TypedEventEmitter<HttpApiEvent, HttpApiEventHandlerMap>();
-                        jest.spyOn(emitter, "emit");
+                        vi.spyOn(emitter, "emit");
                        const api = new FetchHttpApi(emitter, {
                            baseUrl,
                            prefix,
@@ -453,8 +532,9 @@ 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.toThrowError(
                            unknownTokenErr,
                        );

@@ -471,9 +551,9 @@ describe("FetchHttpApi", () => {
        const localBaseUrl = "http://baseurl";
        const baseUrlWithTrailingSlash = "http://baseurl/";
        const makeApi = (thisBaseUrl = baseUrl): FetchHttpApi<any> => {
-            const fetchFn = jest.fn();
+            const fetchFn = vi.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 = {
@@ -524,9 +604,15 @@ describe("FetchHttpApi", () => {

        describe("extraParams handling", () => {
            const makeApiWithExtraParams = (extraParams: QueryDict): FetchHttpApi<any> => {
-                const fetchFn = jest.fn();
+                const fetchFn = vi.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";
@@ -577,9 +663,9 @@ describe("FetchHttpApi", () => {
            });

            it("should work when extraParams is undefined", () => {
-                const fetchFn = jest.fn();
+                const fetchFn = vi.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);
@@ -601,21 +687,22 @@ describe("FetchHttpApi", () => {
    });

    it("should not log query parameters", async () => {
-        jest.useFakeTimers();
+        vi.useFakeTimers();
        const responseResolvers = Promise.withResolvers<Response>();
-        const fetchFn = jest.fn().mockReturnValue(responseResolvers.promise);
+        const fetchFn = vi.fn().mockReturnValue(responseResolvers.promise);
        const mockLogger = {
-            debug: jest.fn(),
+            debug: vi.fn(),
        } as unknown as Mocked<Logger>;
        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
            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);
+        vi.advanceTimersByTime(1234);
+        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");
@@ -635,7 +722,7 @@ describe("FetchHttpApi", () => {

    it("should not make multiple concurrent refresh token requests", async () => {
        const deferredTokenRefresh = Promise.withResolvers<{ accessToken: string; refreshToken: string }>();
-        const fetchFn = jest.fn().mockResolvedValue({
+        const fetchFn = vi.fn().mockResolvedValue({
            ok: false,
            status: tokenInactiveError.httpStatus,
            async text() {
@@ -645,10 +732,10 @@ describe("FetchHttpApi", () => {
                return tokenInactiveError.data;
            },
            headers: {
-                get: jest.fn().mockReturnValue("application/json"),
+                get: vi.fn().mockReturnValue("application/json"),
            },
        });
-        const tokenRefreshFunction = jest.fn().mockReturnValue(deferredTokenRefresh.promise);
+        const tokenRefreshFunction = vi.fn().mockReturnValue(deferredTokenRefresh.promise);

        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
@@ -658,6 +745,7 @@ describe("FetchHttpApi", () => {
            tokenRefreshFunction,
            accessToken: "ACCESS_TOKEN",
            refreshToken: "REFRESH_TOKEN",
+            onlyData: true,
        });

        const prom1 = api.authedRequest(Method.Get, "/path1");
@@ -675,7 +763,7 @@ describe("FetchHttpApi", () => {
                return {};
            },
            headers: {
-                get: jest.fn().mockReturnValue("application/json"),
+                get: vi.fn().mockReturnValue("application/json"),
            },
        });
        deferredTokenRefresh.resolve({ accessToken: "NEW_ACCESS_TOKEN", refreshToken: "NEW_REFRESH_TOKEN" });
@@ -690,7 +778,7 @@ describe("FetchHttpApi", () => {

    it("should use newly refreshed token if request starts mid-refresh", async () => {
        const deferredTokenRefresh = Promise.withResolvers<{ accessToken: string; refreshToken: string }>();
-        const fetchFn = jest.fn().mockResolvedValue({
+        const fetchFn = vi.fn().mockResolvedValue({
            ok: false,
            status: tokenInactiveError.httpStatus,
            async text() {
@@ -700,10 +788,10 @@ describe("FetchHttpApi", () => {
                return tokenInactiveError.data;
            },
            headers: {
-                get: jest.fn().mockReturnValue("application/json"),
+                get: vi.fn().mockReturnValue("application/json"),
            },
        });
-        const tokenRefreshFunction = jest.fn().mockReturnValue(deferredTokenRefresh.promise);
+        const tokenRefreshFunction = vi.fn().mockReturnValue(deferredTokenRefresh.promise);

        const api = new FetchHttpApi(new TypedEventEmitter<any, any>(), {
            baseUrl,
@@ -713,6 +801,7 @@ describe("FetchHttpApi", () => {
            tokenRefreshFunction,
            accessToken: "ACCESS_TOKEN",
            refreshToken: "REFRESH_TOKEN",
+            onlyData: true,
        });

        const prom1 = api.authedRequest(Method.Get, "/path1");
@@ -732,7 +821,7 @@ describe("FetchHttpApi", () => {
                return {};
            },
            headers: {
-                get: jest.fn().mockReturnValue("application/json"),
+                get: vi.fn().mockReturnValue("application/json"),
            },
        });

@@ -750,3 +839,7 @@ describe("FetchHttpApi", () => {
        expect(api.opts.refreshToken).toBe("NEW_REFRESH_TOKEN");
    });
 });
+
+function makeMockFetchFn(): MockedFunction<Window["fetch"]> {
+    return vi.fn().mockResolvedValue({ ok: true, json: vi.fn().mockResolvedValue({}) });
+}
@@ -14,66 +14,71 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { mocked } from "jest-mock";
-
 import { ClientPrefix, MatrixHttpApi, Method, type UploadResponse } from "../../../src";
 import { TypedEventEmitter } from "../../../src/models/typed-event-emitter";

 type Writeable<T> = { -readonly [P in keyof T]: T[P] };

-jest.useFakeTimers();
+vi.useFakeTimers();

 describe("MatrixHttpApi", () => {
    const baseUrl = "http://baseUrl";
    const prefix = ClientPrefix.V3;

-    let xhr: Writeable<XMLHttpRequest>;
    let upload: Promise<UploadResponse>;

    const DONE = 0;

+    function getRequest(): Writeable<XMLHttpRequest> | undefined {
+        return vi.mocked(globalThis.XMLHttpRequest)?.mock.instances.at(-1);
+    }
+
    beforeEach(() => {
-        xhr = {
-            upload: {} as XMLHttpRequestUpload,
-            open: jest.fn(),
-            send: jest.fn(),
-            abort: jest.fn(),
-            setRequestHeader: jest.fn(),
-            onreadystatechange: undefined,
-            getResponseHeader: jest.fn(),
-            getAllResponseHeaders: jest.fn(),
-        } as unknown as XMLHttpRequest;
-        // We stub out XHR here as it is not available in JSDOM
+        // We stub out XHR here as it is not available in the test environment
        // @ts-ignore
-        globalThis.XMLHttpRequest = jest.fn().mockReturnValue(xhr);
+        globalThis.XMLHttpRequest = vi.fn().mockImplementation(function (this: XMLHttpRequest) {
+            // @ts-ignore
+            this.upload = {} as XMLHttpRequestUpload;
+            this.open = vi.fn();
+            this.send = vi.fn();
+            this.abort = vi.fn();
+            this.setRequestHeader = vi.fn();
+            // @ts-ignore
+            this.onreadystatechange = undefined;
+            this.getResponseHeader = vi.fn();
+            this.getAllResponseHeaders = vi.fn();
+        });
        // @ts-ignore
        globalThis.XMLHttpRequest.DONE = DONE;
    });

    afterEach(() => {
        upload?.catch(() => {});
-        // Abort any remaining requests
-        xhr.readyState = DONE;
-        xhr.status = 0;
-        // @ts-ignore
-        xhr.onreadystatechange?.(new Event("test"));
+        const xhr = getRequest();
+        if (xhr) {
+            // Abort any remaining requests
+            xhr.readyState = DONE;
+            xhr.status = 0;
+            // @ts-ignore
+            xhr.onreadystatechange?.(new Event("test"));
+        }
    });

    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 fetchFn = vi.fn().mockResolvedValue({ ok: true, json: vi.fn().mockResolvedValue({}) });
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, fetchFn, onlyData: true });
        upload = api.uploadContent({} as File);
        await upload;
        expect(fetchFn).toHaveBeenCalled();
    });

    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 fetchFn = vi.fn().mockResolvedValue({ ok: true });
+        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();
+        expect(getRequest()!.open).toHaveBeenCalled();
    });

    it("should send access token in query params if header disabled", () => {
@@ -82,13 +87,14 @@ describe("MatrixHttpApi", () => {
            prefix,
            accessToken: "token",
            useAuthorizationHeader: false,
+            onlyData: true,
        });
        upload = api.uploadContent({} as File);
-        expect(xhr.open).toHaveBeenCalledWith(
+        expect(getRequest()!.open).toHaveBeenCalledWith(
            Method.Post,
            baseUrl.toLowerCase() + "/_matrix/media/v3/upload?access_token=token",
        );
-        expect(xhr.setRequestHeader).not.toHaveBeenCalledWith("Authorization");
+        expect(getRequest()!.setRequestHeader).not.toHaveBeenCalledWith("Authorization");
    });

    it("should send access token in header by default", () => {
@@ -96,131 +102,138 @@ 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");
-        expect(xhr.setRequestHeader).toHaveBeenCalledWith("Authorization", "Bearer token");
+        expect(getRequest()!.open).toHaveBeenCalledWith(
+            Method.Post,
+            baseUrl.toLowerCase() + "/_matrix/media/v3/upload",
+        );
+        expect(getRequest()!.setRequestHeader).toHaveBeenCalledWith("Authorization", "Bearer token");
    });

    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(
+        expect(getRequest()!.open).toHaveBeenCalledWith(
            Method.Post,
            baseUrl.toLowerCase() + "/_matrix/media/v3/upload?filename=name",
        );
    });

    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");
+        expect(getRequest()!.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();
+        expect(getRequest()!.abort).toHaveBeenCalled();
        return expect(upload).rejects.toThrow("Aborted");
    });

    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);
+        vi.advanceTimersByTime(25000);
        // @ts-ignore
-        xhr.upload.onprogress(new Event("progress", { loaded: 1, total: 100 }));
-        jest.advanceTimersByTime(25000);
-        expect(xhr.abort).not.toHaveBeenCalled();
-        jest.advanceTimersByTime(5000);
-        expect(xhr.abort).toHaveBeenCalled();
+        getRequest()!.upload.onprogress(new Event("progress", { loaded: 1, total: 100 }));
+        vi.advanceTimersByTime(25000);
+        expect(getRequest()!.abort).not.toHaveBeenCalled();
+        vi.advanceTimersByTime(5000);
+        expect(getRequest()!.abort).toHaveBeenCalled();
    });

    it("should call progressHandler", () => {
-        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix });
-        const progressHandler = jest.fn();
+        const api = new MatrixHttpApi(new TypedEventEmitter<any, any>(), { baseUrl, prefix, onlyData: true });
+        const progressHandler = vi.fn();
        upload = api.uploadContent({} as File, { progressHandler });
        const progressEvent = new Event("progress") as ProgressEvent;
        Object.assign(progressEvent, { loaded: 1, total: 100 });
        // @ts-ignore
-        xhr.upload.onprogress(progressEvent);
+        getRequest()!.upload.onprogress(progressEvent);
        expect(progressHandler).toHaveBeenCalledWith({ loaded: 1, total: 100 });

        Object.assign(progressEvent, { loaded: 95, total: 100 });
        // @ts-ignore
-        xhr.upload.onprogress(progressEvent);
+        getRequest()!.upload.onprogress(progressEvent);
        expect(progressHandler).toHaveBeenCalledWith({ loaded: 95, total: 100 });
    });

    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;
-        xhr.responseText = "";
-        xhr.status = 200;
+        getRequest()!.readyState = DONE;
+        getRequest()!.responseText = "";
+        getRequest()!.status = 200;
        // @ts-ignore
-        xhr.onreadystatechange?.(new Event("test"));
+        getRequest()!.onreadystatechange?.(new Event("test"));

        return expect(upload).rejects.toThrow("No response body.");
    });

    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;
-        xhr.responseText = '{"errcode": "M_NOT_FOUND", "error": "Not found"}';
-        xhr.status = 404;
-        mocked(xhr.getResponseHeader).mockImplementation((name) =>
+        getRequest()!.readyState = DONE;
+        getRequest()!.responseText = '{"errcode": "M_NOT_FOUND", "error": "Not found"}';
+        getRequest()!.status = 404;
+        vi.mocked(getRequest()!.getResponseHeader).mockImplementation((name) =>
            name.toLowerCase() === "content-type" ? "application/json" : null,
        );
-        mocked(xhr.getAllResponseHeaders).mockReturnValue("content-type: application/json\r\n");
+        vi.mocked(getRequest()!.getAllResponseHeaders).mockReturnValue("content-type: application/json\r\n");
        // @ts-ignore
-        xhr.onreadystatechange?.(new Event("test"));
+        getRequest()!.onreadystatechange?.(new Event("test"));

        return expect(upload).rejects.toThrow("Not found");
    });

    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;
-        xhr.responseText = '{"content_uri": "mxc://server/foobar"}';
-        xhr.status = 200;
-        mocked(xhr.getResponseHeader).mockReturnValue("application/json");
+        getRequest()!.readyState = DONE;
+        getRequest()!.responseText = '{"content_uri": "mxc://server/foobar"}';
+        getRequest()!.status = 200;
+        vi.mocked(getRequest()!.getResponseHeader).mockReturnValue("application/json");
        // @ts-ignore
-        xhr.onreadystatechange?.(new Event("test"));
+        getRequest()!.onreadystatechange?.(new Event("test"));

        return expect(upload).resolves.toStrictEqual({ content_uri: "mxc://server/foobar" });
    });

    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();
+        expect(getRequest()!.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;
-        xhr.status = 500;
-        mocked(xhr.getResponseHeader).mockReturnValue("application/json");
+        getRequest()!.readyState = DONE;
+        getRequest()!.status = 500;
+        vi.mocked(getRequest()!.getResponseHeader).mockReturnValue("application/json");
        // @ts-ignore
-        xhr.onreadystatechange?.(new Event("test"));
+        getRequest()!.onreadystatechange?.(new Event("test"));
        await upload.catch(() => {});

        expect(api.cancelUpload(upload)).toBeFalsy();
-        expect(xhr.abort).not.toHaveBeenCalled();
+        expect(getRequest()!.abort).not.toHaveBeenCalled();
    });

    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 +241,12 @@ 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();
    });
 });
@@ -14,51 +14,51 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { mocked } from "jest-mock";
-
 import {
    anySignal,
    ConnectionError,
    HTTPError,
    MatrixError,
+    MatrixSafetyError,
+    MatrixSafetyErrorCode,
    parseErrorResponse,
    retryNetworkOperation,
    timeoutSignal,
 } from "../../../src";
 import { sleep } from "../../../src/utils";

-jest.mock("../../../src/utils");
+vi.mock("../../../src/utils");
 // setupTests mocks `timeoutSignal` due to hanging timers
-jest.unmock("../../../src/http-api/utils");
+vi.unmock("../../../src/http-api/utils");

 describe("timeoutSignal", () => {
-    jest.useFakeTimers();
+    vi.useFakeTimers();

    it("should fire abort signal after specified timeout", () => {
        const signal = timeoutSignal(3000);
-        const onabort = jest.fn();
+        const onabort = vi.fn();
        signal.onabort = onabort;
        expect(signal.aborted).toBeFalsy();
        expect(onabort).not.toHaveBeenCalled();

-        jest.advanceTimersByTime(3000);
+        vi.advanceTimersByTime(3000);
        expect(signal.aborted).toBeTruthy();
        expect(onabort).toHaveBeenCalled();
    });
 });

 describe("anySignal", () => {
-    jest.useFakeTimers();
+    vi.useFakeTimers();

    it("should fire when any signal fires", () => {
        const { signal } = anySignal([timeoutSignal(3000), timeoutSignal(2000)]);

-        const onabort = jest.fn();
+        const onabort = vi.fn();
        signal.onabort = onabort;
        expect(signal.aborted).toBeFalsy();
        expect(onabort).not.toHaveBeenCalled();

-        jest.advanceTimersByTime(2000);
+        vi.advanceTimersByTime(2000);
        expect(signal.aborted).toBeTruthy();
        expect(onabort).toHaveBeenCalled();
    });
@@ -66,13 +66,13 @@ describe("anySignal", () => {
    it("should cleanup when instructed", () => {
        const { signal, cleanup } = anySignal([timeoutSignal(3000), timeoutSignal(2000)]);

-        const onabort = jest.fn();
+        const onabort = vi.fn();
        signal.onabort = onabort;
        expect(signal.aborted).toBeFalsy();
        expect(onabort).not.toHaveBeenCalled();

        cleanup();
-        jest.advanceTimersByTime(2000);
+        vi.advanceTimersByTime(2000);
        expect(signal.aborted).toBeFalsy();
        expect(onabort).not.toHaveBeenCalled();
    });
@@ -86,9 +86,14 @@ describe("anySignal", () => {
 });

 describe("parseErrorResponse", () => {
+    const url = "https://example.org";
+
    let headers: Headers;
    const xhrHeaderMethods = {
-        getResponseHeader: (name: string) => headers.get(name),
+        responseURL: url,
+        getResponseHeader: (name: string) => {
+            headers.get(name);
+        },
        getAllResponseHeaders: () => {
            let allHeaders = "";
            headers.forEach((value, key) => {
@@ -118,6 +123,9 @@ describe("parseErrorResponse", () => {
                    errcode: "TEST",
                },
                500,
+                url,
+                undefined,
+                expect.any(Headers),
            ),
        );
    });
@@ -127,6 +135,7 @@ describe("parseErrorResponse", () => {
        expect(
            parseErrorResponse(
                {
+                    url,
                    headers,
                    status: 500,
                } as Response,
@@ -138,6 +147,9 @@ describe("parseErrorResponse", () => {
                    errcode: "TEST",
                },
                500,
+                url,
+                undefined,
+                expect.any(Headers),
            ),
        );
    });
@@ -147,8 +159,8 @@ describe("parseErrorResponse", () => {
        expect(
            parseErrorResponse(
                {
-                    responseURL: "https://example.com",
                    ...xhrHeaderMethods,
+                    responseURL: "https://example.com",
                    status: 500,
                } as XMLHttpRequest,
                '{"errcode": "TEST"}',
@@ -160,6 +172,8 @@ describe("parseErrorResponse", () => {
                },
                500,
                "https://example.com",
+                undefined,
+                expect.any(Headers),
            ),
        );
    });
@@ -182,9 +196,40 @@ describe("parseErrorResponse", () => {
                },
                500,
                "https://example.com",
+                undefined,
+                expect.any(Headers),
            ),
        );
    });
+    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) {
@@ -196,7 +241,7 @@ describe("parseErrorResponse", () => {
        }

        function compareHeaders(expectedHeaders: Headers, otherHeaders: Headers | undefined) {
-            expect(new Map(otherHeaders)).toEqual(new Map(expectedHeaders));
+            expect(new Map(otherHeaders as any)).toEqual(new Map(expectedHeaders as any));
        }

        it("should resolve HTTP Errors from XHR with headers", () => {
@@ -265,7 +310,7 @@ describe("parseErrorResponse", () => {
                } as Response,
                '{"errcode": "TEST"}',
            ),
-        ).toStrictEqual(new HTTPError("Server returned 500 error", 500));
+        ).toStrictEqual(new HTTPError("Server returned 500 error", 500, expect.any(Headers)));
    });

    it("should handle empty type gracefully", () => {
@@ -304,27 +349,27 @@ describe("parseErrorResponse", () => {
                } as Response,
                "I'm a teapot",
            ),
-        ).toStrictEqual(new HTTPError("Server returned 418 error: I'm a teapot", 418));
+        ).toStrictEqual(new HTTPError("Server returned 418 error: I'm a teapot", 418, expect.any(Headers)));
    });
 });

 describe("retryNetworkOperation", () => {
    it("should retry given number of times with exponential sleeps", async () => {
        const err = new ConnectionError("test");
-        const fn = jest.fn().mockRejectedValue(err);
-        mocked(sleep).mockResolvedValue(undefined);
+        const fn = vi.fn().mockRejectedValue(err);
+        vi.mocked(sleep).mockResolvedValue(undefined);
        await expect(retryNetworkOperation(4, fn)).rejects.toThrow(err);
        expect(fn).toHaveBeenCalledTimes(4);
-        expect(mocked(sleep)).toHaveBeenCalledTimes(3);
-        expect(mocked(sleep).mock.calls[0][0]).toBe(2000);
-        expect(mocked(sleep).mock.calls[1][0]).toBe(4000);
-        expect(mocked(sleep).mock.calls[2][0]).toBe(8000);
+        expect(vi.mocked(sleep)).toHaveBeenCalledTimes(3);
+        expect(vi.mocked(sleep).mock.calls[0][0]).toBe(2000);
+        expect(vi.mocked(sleep).mock.calls[1][0]).toBe(4000);
+        expect(vi.mocked(sleep).mock.calls[2][0]).toBe(8000);
    });

    it("should bail out on errors other than ConnectionError", async () => {
        const err = new TypeError("invalid JSON");
-        const fn = jest.fn().mockRejectedValue(err);
-        mocked(sleep).mockResolvedValue(undefined);
+        const fn = vi.fn().mockRejectedValue(err);
+        vi.mocked(sleep).mockResolvedValue(undefined);
        await expect(retryNetworkOperation(3, fn)).rejects.toThrow(err);
        expect(fn).toHaveBeenCalledTimes(1);
    });
@@ -334,10 +379,10 @@ describe("retryNetworkOperation", () => {
        const err2 = new ConnectionError("test2");
        const err3 = new ConnectionError("test3");
        const errors = [err1, err2, err3];
-        const fn = jest.fn().mockImplementation(() => {
+        const fn = vi.fn().mockImplementation(() => {
            throw errors.shift();
        });
-        mocked(sleep).mockResolvedValue(undefined);
+        vi.mocked(sleep).mockResolvedValue(undefined);
        await expect(retryNetworkOperation(3, fn)).rejects.toThrow(err3);
    });
 });
@@ -17,7 +17,7 @@ limitations under the License.

 import { type MatrixClient } from "../../src/client";
 import { logger } from "../../src/logger";
-import { InteractiveAuth, AuthType } from "../../src/interactive-auth";
+import { InteractiveAuth, AuthType, NoAuthFlowFoundError } from "../../src/interactive-auth";
 import { HTTPError, MatrixError } from "../../src/http-api";
 import { sleep } from "../../src/utils";
 import { secureRandomString } from "../../src/randomstring";
@@ -34,14 +34,14 @@ const getFakeClient = (): MatrixClient => new FakeClient() as unknown as MatrixC

 describe("InteractiveAuth", () => {
    it("should start an auth stage and complete it", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
            doRequest: doRequest,
            stateUpdated: stateUpdated,
-            requestEmailToken: jest.fn(),
+            requestEmailToken: vi.fn(),
            authData: {
                session: "sessionId",
                flows: [{ stages: [AuthType.Password] }],
@@ -83,14 +83,14 @@ describe("InteractiveAuth", () => {
    });

    it("should handle auth errcode presence", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
            doRequest: doRequest,
            stateUpdated: stateUpdated,
-            requestEmailToken: jest.fn(),
+            requestEmailToken: vi.fn(),
            authData: {
                session: "sessionId",
                flows: [{ stages: [AuthType.Password] }],
@@ -132,9 +132,9 @@ describe("InteractiveAuth", () => {
    });

    it("should handle set emailSid for email flow", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            doRequest,
@@ -186,9 +186,9 @@ describe("InteractiveAuth", () => {
    });

    it("should make a request if no authdata is provided", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -248,9 +248,9 @@ describe("InteractiveAuth", () => {
    });

    it("should make a request if authdata is null", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -310,9 +310,9 @@ describe("InteractiveAuth", () => {
    });

    it("should start an auth stage and reject if no auth flow", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -337,13 +337,15 @@ describe("InteractiveAuth", () => {
            throw err;
        });

-        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(new Error("No appropriate authentication flow found"));
+        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(
+            new NoAuthFlowFoundError("No appropriate authentication flow found", [], []),
+        );
    });

    it("should start an auth stage and reject if no auth flow but has session", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -372,13 +374,15 @@ describe("InteractiveAuth", () => {
            throw err;
        });

-        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(new Error("No appropriate authentication flow found"));
+        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(
+            new NoAuthFlowFoundError("No appropriate authentication flow found", [], []),
+        );
    });

    it("should handle unexpected error types without data property set", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -397,13 +401,13 @@ describe("InteractiveAuth", () => {
            throw err;
        });

-        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(new Error("myerror"));
+        await expect(ia.attemptAuth.bind(ia)).rejects.toThrow(new HTTPError("myerror", 401));
    });

    it("should allow dummy auth", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
-        const requestEmailToken = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();
+        const requestEmailToken = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
@@ -435,9 +439,9 @@ describe("InteractiveAuth", () => {

    describe("requestEmailToken", () => {
        it("increases auth attempts", async () => {
-            const doRequest = jest.fn();
-            const stateUpdated = jest.fn();
-            const requestEmailToken = jest.fn();
+            const doRequest = vi.fn();
+            const stateUpdated = vi.fn();
+            const requestEmailToken = vi.fn();
            requestEmailToken.mockImplementation(async () => ({ sid: "" }));

            const ia = new InteractiveAuth({
@@ -464,9 +468,9 @@ describe("InteractiveAuth", () => {
        });

        it("passes errors through", async () => {
-            const doRequest = jest.fn();
-            const stateUpdated = jest.fn();
-            const requestEmailToken = jest.fn();
+            const doRequest = vi.fn();
+            const stateUpdated = vi.fn();
+            const requestEmailToken = vi.fn();
            requestEmailToken.mockImplementation(async () => {
                throw new Error("unspecific network error");
            });
@@ -482,9 +486,9 @@ describe("InteractiveAuth", () => {
        });

        it("only starts one request at a time", async () => {
-            const doRequest = jest.fn();
-            const stateUpdated = jest.fn();
-            const requestEmailToken = jest.fn();
+            const doRequest = vi.fn();
+            const stateUpdated = vi.fn();
+            const requestEmailToken = vi.fn();
            requestEmailToken.mockImplementation(() => sleep(500, { sid: "" }));

            const ia = new InteractiveAuth({
@@ -499,9 +503,9 @@ describe("InteractiveAuth", () => {
        });

        it("stores result in email sid", async () => {
-            const doRequest = jest.fn();
-            const stateUpdated = jest.fn();
-            const requestEmailToken = jest.fn();
+            const doRequest = vi.fn();
+            const stateUpdated = vi.fn();
+            const requestEmailToken = vi.fn();
            const sid = secureRandomString(24);
            requestEmailToken.mockImplementation(() => sleep(500, { sid }));

@@ -518,14 +522,14 @@ describe("InteractiveAuth", () => {
    });

    it("should prioritise shorter flows", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
            doRequest: doRequest,
            stateUpdated: stateUpdated,
-            requestEmailToken: jest.fn(),
+            requestEmailToken: vi.fn(),
            authData: {
                session: "sessionId",
                flows: [{ stages: [AuthType.Recaptcha, AuthType.Password] }, { stages: [AuthType.Password] }],
@@ -539,14 +543,14 @@ describe("InteractiveAuth", () => {
    });

    it("should prioritise flows with entirely supported stages", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
            doRequest: doRequest,
            stateUpdated: stateUpdated,
-            requestEmailToken: jest.fn(),
+            requestEmailToken: vi.fn(),
            authData: {
                session: "sessionId",
                flows: [{ stages: ["com.devture.shared_secret_auth"] }, { stages: [AuthType.Password] }],
@@ -561,14 +565,14 @@ describe("InteractiveAuth", () => {
    });

    it("should fire stateUpdated callback with error when a request fails", async () => {
-        const doRequest = jest.fn();
-        const stateUpdated = jest.fn();
+        const doRequest = vi.fn();
+        const stateUpdated = vi.fn();

        const ia = new InteractiveAuth({
            matrixClient: getFakeClient(),
            doRequest: doRequest,
            stateUpdated: stateUpdated,
-            requestEmailToken: jest.fn(),
+            requestEmailToken: vi.fn(),
            authData: {
                session: "sessionId",
                flows: [{ stages: [AuthType.Password] }],
@@ -23,7 +23,7 @@ let client: MatrixClient;
 describe("Local notification settings", () => {
    beforeEach(() => {
        client = new TestClient("@alice:matrix.org", "123", undefined, undefined, undefined).client;
-        client.setAccountData = jest.fn();
+        client.setAccountData = vi.fn();
    });

    describe("Lets you set local notification settings", () => {
@@ -18,15 +18,15 @@ limitations under the License.

 import loglevel from "loglevel";

-import { logger } from "../../src/logger.ts";
+import { DebugLogger, logger } from "../../src/logger.ts";

 afterEach(() => {
-    jest.restoreAllMocks();
+    vi.restoreAllMocks();
 });

 describe("logger", () => {
    it("should log to console by default", () => {
-        jest.spyOn(console, "debug").mockReturnValue(undefined);
+        vi.spyOn(console, "debug").mockReturnValue(undefined);
        logger.debug("test1");
        logger.log("test2");

@@ -35,8 +35,8 @@ describe("logger", () => {
    });

    it("should allow creation of child loggers which add a prefix", () => {
-        jest.spyOn(loglevel, "getLogger");
-        jest.spyOn(console, "debug").mockReturnValue(undefined);
+        vi.spyOn(loglevel, "getLogger");
+        vi.spyOn(console, "debug").mockReturnValue(undefined);

        const childLogger = logger.getChild("[prefix1]");
        expect(loglevel.getLogger).toHaveBeenCalledWith("matrix-[prefix1]");
@@ -49,3 +49,42 @@ describe("logger", () => {
        expect(console.debug).toHaveBeenCalledWith("[prefix1][prefix2]", "test2");
    });
 });
+
+describe("DebugLogger", () => {
+    it("should handle empty log messages", () => {
+        const mockTarget = vi.fn();
+        const logger = new DebugLogger(mockTarget as any);
+        logger.info();
+        expect(mockTarget).toHaveBeenCalledTimes(1);
+        expect(mockTarget).toHaveBeenCalledWith("[INFO] ");
+    });
+
+    it("should handle logging an Error", () => {
+        const mockTarget = vi.fn();
+        const logger = new DebugLogger(mockTarget as any);
+
+        // If there is a stack and a message, we use the stack.
+        const error = new Error("I am an error");
+        logger.error(error);
+        expect(mockTarget).toHaveBeenCalledTimes(1);
+        expect(mockTarget).toHaveBeenCalledWith(expect.stringMatching(/^\[ERROR\] Error: I am an error\n\s*at/));
+
+        mockTarget.mockClear();
+
+        // If there is only a message, we use that.
+        error.stack = undefined;
+        logger.error(error);
+        expect(mockTarget).toHaveBeenCalledTimes(1);
+        expect(mockTarget).toHaveBeenCalledWith("[ERROR] I am an error");
+    });
+
+    it("should handle logging an object", () => {
+        const mockTarget = vi.fn();
+        const logger = new DebugLogger(mockTarget as any);
+
+        const obj = { a: 1 };
+        logger.warn(obj);
+        expect(mockTarget).toHaveBeenCalledTimes(1);
+        expect(mockTarget).toHaveBeenCalledWith("[WARN] %O", obj);
+    });
+});
@@ -1,4 +1,4 @@
-import fetchMock from "fetch-mock-jest";
+import fetchMock from "@fetch-mock/vitest";

 import { ClientPrefix, MatrixClient } from "../../src";
 import { SSOAction } from "../../src/@types/auth";
@@ -51,27 +51,26 @@ describe("SSO login URL", function () {
            const urlString = client.client.getSsoLoginUrl(redirectUri, undefined, undefined, undefined);
            const url = new URL(urlString);
            expect(url.searchParams.has("org.matrix.msc3824.action")).toBe(false);
+            expect(url.searchParams.has("action")).toBe(false);
        });

        it("register", function () {
            const urlString = client.client.getSsoLoginUrl(redirectUri, undefined, undefined, SSOAction.REGISTER);
            const url = new URL(urlString);
            expect(url.searchParams.get("org.matrix.msc3824.action")).toEqual("register");
+            expect(url.searchParams.get("action")).toEqual("register");
        });

        it("login", function () {
            const urlString = client.client.getSsoLoginUrl(redirectUri, undefined, undefined, SSOAction.LOGIN);
            const url = new URL(urlString);
            expect(url.searchParams.get("org.matrix.msc3824.action")).toEqual("login");
+            expect(url.searchParams.get("action")).toEqual("login");
        });
    });
 });

 describe("refreshToken", () => {
-    afterEach(() => {
-        fetchMock.mockReset();
-    });
-
    it("requests the correctly-prefixed /refresh endpoint when server correctly accepts /v3", async () => {
        const client = createExampleMatrixClient();

@@ -1,5 +1,5 @@
 /*
-Copyright 2023 The Matrix.org Foundation C.I.C.
+Copyright 2023-2026 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.
@@ -14,65 +14,71 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */

-import { type MatrixEvent } from "../../../src";
-import {
-    CallMembership,
-    type SessionMembershipData,
-    DEFAULT_EXPIRE_DURATION,
-} from "../../../src/matrixrtc/CallMembership";
-import { membershipTemplate } from "./mocks";
+import { type RtcMembershipData, type SessionMembershipData } from "../../../src/matrixrtc/membershipData/index.ts";
+import { type IContent, type MatrixEvent } from "../../../src/models/event.ts";
+import { EventType } from "../../../src/@types/event.ts";
+import { CallMembership, DEFAULT_EXPIRE_DURATION } from "../../../src/matrixrtc/CallMembership.ts";

-function makeMockEvent(originTs = 0): MatrixEvent {
-    return {
-        getTs: jest.fn().mockReturnValue(originTs),
-        getSender: jest.fn().mockReturnValue("@alice:example.org"),
-    } as unknown as MatrixEvent;
+function createCallMembership(ev: MatrixEvent, content: IContent): CallMembership {
+    vi.mocked(ev.getContent).mockReturnValue(content);
+    const data = CallMembership.membershipDataFromMatrixEvent(ev);
+    return new CallMembership(ev, data, "xx");
 }

 describe("CallMembership", () => {
    describe("SessionMembershipData", () => {
+        function makeMockEvent(originTs = 0): MatrixEvent {
+            return {
+                getTs: vi.fn().mockReturnValue(originTs),
+                getSender: vi.fn().mockReturnValue("@alice:example.org"),
+                getId: vi.fn().mockReturnValue("$eventid"),
+                getContent: vi.fn().mockReturnValue({}),
+                getType: vi.fn().mockReturnValue(EventType.GroupCallMemberPrefix),
+            } as unknown as MatrixEvent;
+        }
        beforeEach(() => {
-            jest.useFakeTimers();
+            vi.useFakeTimers();
        });

        afterEach(() => {
-            jest.useRealTimers();
+            vi.useRealTimers();
        });

        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 }),
            );
@@ -81,47 +87,347 @@ 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);
+            fakeEvent.getTs = vi.fn().mockReturnValue(Date.now() - (DEFAULT_EXPIRE_DURATION - 1));
+            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);
+            fakeEvent.getTs = vi.fn().mockReturnValue(Date.now() - (DEFAULT_EXPIRE_DURATION + 1));
+            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", () => {
+                // slot_id is application and call_id dependent. So we create
+                // a membership for each possible combination
+
+                // non call application (should not alter call_id even with empty string)
+                const nonCallMembership = createCallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    application: "m.not.a.call",
+                    call_id: "",
+                });
+                // non "" call id should not be altered
+                const callMembershipCustomId = createCallMembership(makeMockEvent(), {
+                    ...membershipTemplate,
+                    call_id: "customCallId",
+                });
+
+                // for membership (application = m.call and call_id = "") we expect "" -> ROOM
+                // for legacy events we expect the room to be added automagically
+                // See INFO_SLOT_ID_LEGACY_CASE comments
+                expect(membership.slotId).toBe("m.call#ROOM");
+                expect(membership.slotDescription).toStrictEqual({ id: "ROOM", application: "m.call" });
+
+                expect(nonCallMembership.slotId).toBe("m.not.a.call#");
+                expect(nonCallMembership.slotDescription).toStrictEqual({ id: "", application: "m.not.a.call" });
+
+                expect(callMembershipCustomId.slotId).toBe("m.call#customCallId");
+                expect(callMembershipCustomId.slotDescription).toStrictEqual({
+                    id: "customCallId",
+                    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("expiry calculation", () => {
+            let fakeEvent: MatrixEvent;
+            let membership: CallMembership;
+
+            beforeEach(() => {
+                // server origin timestamp for this event is 1000
+                fakeEvent = makeMockEvent(1000);
+                membership = createCallMembership(fakeEvent!, membershipTemplate);
+
+                vi.useFakeTimers();
+            });
+
+            afterEach(() => {
+                vi.useFakeTimers();
+            });
+
+            it("calculates time until expiry", () => {
+                vi.setSystemTime(2000);
+                // should be using absolute expiry time
+                expect(membership.getMsUntilExpiry()).toEqual(DEFAULT_EXPIRE_DURATION - 1000);
+            });
        });
    });

-    describe("expiry calculation", () => {
-        let fakeEvent: MatrixEvent;
-        let membership: CallMembership;
+    describe("RtcMembershipData", () => {
+        function makeMockEvent(originTs = 0, content: IContent = {}): MatrixEvent {
+            return {
+                getTs: vi.fn().mockReturnValue(originTs),
+                getSender: vi.fn().mockReturnValue("@alice:example.org"),
+                getId: vi.fn().mockReturnValue("$eventid"),
+                getContent: vi.fn().mockReturnValue(content),
+                getType: vi.fn().mockReturnValue(EventType.RTCMembership),
+            } as unknown as MatrixEvent;
+        }
+        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",
+        };

-        beforeEach(() => {
-            // server origin timestamp for this event is 1000
-            fakeEvent = makeMockEvent(1000);
-            membership = new CallMembership(fakeEvent!, membershipTemplate);
-
-            jest.useFakeTimers();
+        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("rejects membership with slot_id that contains extra #", () => {
+            expect(() => {
+                createCallMembership(makeMockEvent(), { ...membershipTemplate, slot_id: "m.call#mycall#extra" });
+            }).toThrow();
+        });
+        it("accepts membership with valid slot_id", () => {
+            expect(() => {
+                createCallMembership(makeMockEvent(), { ...membershipTemplate, slot_id: "m.call#" });
+            }).not.toThrow();
        });

-        afterEach(() => {
-            jest.useRealTimers();
+        it("rejects membership with no application", () => {
+            expect(() => {
+                createCallMembership(makeMockEvent(), { ...membershipTemplate, application: undefined });
+            }).toThrow();
        });

-        it("calculates time until expiry", () => {
-            jest.setSystemTime(2000);
-            // should be using absolute expiry time
-            expect(membership.getMsUntilExpiry()).toEqual(DEFAULT_EXPIRE_DURATION - 1000);
+        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();
+        });
+
+        // TODO link prev event
+        it.todo("considers memberships unexpired if local age low enough");
+        it.todo("considers memberships expired if local age large enough");
+
+        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);
+            });
+        });
+        it("uses unpadded base64 for RTC backend identities", async () => {
+            const membership = await CallMembership.parseFromEvent(makeMockEvent(0, { ...membershipTemplate }));
+            expect(membership.rtcBackendIdentity).toBe("jUZ0Q1yF5nV3LlAI5xfD1I7BPnAytJaPEAR57EXjJ6s");
        });
    });
 });
@@ -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();
    });
 });
--- a/Show More
+++ b/Show More