diff --git a/.github/workflows/source-snapshot.yml b/.github/workflows/source-snapshot.yml
new file mode 100644
index 0000000..b7c2057
--- /dev/null
+++ b/.github/workflows/source-snapshot.yml
@@ -0,0 +1,32 @@
+name: source-snapshot
+
+on:
+  push:
+    branches:
+      - chore/source-snapshot-20260823
+  pull_request:
+    branches:
+      - main
+
+permissions:
+  contents: read
+
+jobs:
+  snapshot:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    steps:
+      - name: Check out source
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: Create source archive
+        shell: bash
+        run: tar --exclude=.git -czf "$RUNNER_TEMP/pmgs-reference-source.tgz" .
+      - name: Upload source archive
+        uses: actions/upload-artifact@v4
+        with:
+          name: pmgs-reference-source
+          path: ${{ runner.temp }}/pmgs-reference-source.tgz
+          if-no-files-found: error
+          retention-days: 1