diff --git a/.github/workflows/cypress.yaml b/.github/workflows/cypress.yaml
index bb2a88b9d2..c4d23ae2da 100644
--- a/.github/workflows/cypress.yaml
+++ b/.github/workflows/cypress.yaml
@@ -1,13 +1,33 @@
 # Triggers after the layered build has finished, taking the artifact and running cypress on it
+#
+# Also called by a workflow in matrix-js-sdk.
+#
 name: Cypress End to End Tests
 on:
     workflow_run:
         workflows: ["Element Web - Build"]
         types:
             - completed
+
+    # support calls from other workflows
+    workflow_call:
+        inputs:
+            react-sdk-repository:
+                type: string
+                required: true
+                description: "The name of the github repository to check out and build."
+            rust-crypto:
+                type: boolean
+                required: false
+                description: "Enable Rust cryptography for the cypress run."
+        secrets:
+            CYPRESS_RECORD_KEY:
+                required: true
+
 concurrency:
     group: ${{ github.workflow }}-${{ github.event.workflow_run.head_branch || github.run_id }}
     cancel-in-progress: ${{ github.event.workflow_run.event == 'pull_request' }}
+
 jobs:
     prepare:
         name: Prepare
@@ -129,11 +149,20 @@ jobs:
                   # XXX: We're checking out untrusted code in a secure context
                   # We need to be careful to not trust anything this code outputs/may do
                   #
-                  # Note that we check out from the default repository, which is (for this workflow) the
+                  # Note that (in the absence of a `react-sdk-repository` input),
+                  # we check out from the default repository, which is (for this workflow) the
                   # *target* repository for the pull request.
+                  #
                   ref: ${{ steps.sha.outputs.sha }}
                   persist-credentials: false
                   path: matrix-react-sdk
+                  repository: ${{ inputs.react-sdk-repository || github.repository }}
+
+            # Enable rust crypto if the calling workflow requests it
+            - name: Enable rust crypto
+              if: inputs.rust-crypto
+              run: |
+                  echo "CYPRESS_RUST_CRYPTO=1" >> "$GITHUB_ENV"
 
             - name: Run Cypress tests
               uses: cypress-io/github-action@40a1a26c08d0e549e8516612ecebbd1ab5eeec8f
diff --git a/.github/workflows/element-web.yaml b/.github/workflows/element-web.yaml
index e08803c216..d369641f17 100644
--- a/.github/workflows/element-web.yaml
+++ b/.github/workflows/element-web.yaml
@@ -12,6 +12,20 @@ on:
         branches: [develop, master]
     repository_dispatch:
         types: [upstream-sdk-notify]
+
+    # support triggering from other workflows
+    workflow_call:
+        inputs:
+            react-sdk-repository:
+                type: string
+                required: true
+                description: "The name of the github repository to check out and build."
+
+            matrix-js-sdk-sha:
+                type: string
+                required: false
+                description: "The Git SHA of matrix-js-sdk to build against. By default, will use a matching branch name if it exists, or develop."
+
 concurrency:
     group: ${{ github.workflow }}-${{ github.ref }}-${{ github.event_name }}
     cancel-in-progress: true
@@ -25,7 +39,10 @@ jobs:
         name: "Build Element-Web"
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v3
+            - name: Checkout code
+              uses: actions/checkout@v3
+              with:
+                  repository: ${{ inputs.react-sdk-repository || github.repository }}
 
             - uses: actions/setup-node@v3
               with:
@@ -33,6 +50,9 @@ jobs:
 
             - name: Fetch layered build
               id: layered_build
+              env:
+                  # tell layered.sh to check out the right sha of the JS-SDK, if we were given one
+                  JS_SDK_GITHUB_BASE_REF: ${{ inputs.matrix-js-sdk-sha }}
               run: |
                   scripts/ci/layered.sh
                   JSSDK_SHA=$(git -C matrix-js-sdk rev-parse --short=12 HEAD)
@@ -44,7 +64,6 @@ jobs:
               run: cp element.io/develop/config.json config.json
               working-directory: ./element-web
 
-            # After building we write the version file and the react-sdk sha so our cypress tests are from the same sha
             - name: Build
               env:
                   CI_PACKAGE: true
@@ -52,9 +71,13 @@ jobs:
               run: |
                   yarn build
                   echo $VERSION > webapp/version
-                  echo $GITHUB_SHA > webapp/sha
               working-directory: ./element-web
 
+            # Record the react-sdk sha so our cypress tests are from the same sha
+            - name: Record react-sdk SHA
+              run: |
+                  git rev-parse HEAD > element-web/webapp/sha
+
             - name: Upload Artifact
               uses: actions/upload-artifact@v3
               with: