diff --git a/.github/workflows/versioning.yml b/.github/workflows/versioning.yml
new file mode 100644
index 00000000..337cc88d
--- /dev/null
+++ b/.github/workflows/versioning.yml
@@ -0,0 +1,24 @@
+# Sandbox proxy for the CI_Toolkit versioning check.
+# Calls the composite action directly: CI_Toolkit has no reusable
+# .github/workflows/ci-versioning.yml, only .github/actions/ci-versioning.
+# Pinned to the validation branch, not develop.
+
+name: Versioning
+
+on:
+  pull_request:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}-${{ github.event_name }}
+  cancel-in-progress: true
+
+jobs:
+  ci-versioning:
+    runs-on: windows-2025-vs2026
+    timeout-minutes: 90
+    steps:
+      - name: Run versioning
+        uses: BuroHappoldEngineeringAdmin/CI_Toolkit/.github/actions/ci-versioning@validate/versioning-eventmessage-traversal
+        with:
+          app_id: ${{ secrets.BHOM_APP_ID }}
+          private_key: ${{ secrets.BHOM_APP_PRIVATE_KEY }}
diff --git a/File_Adapter/AdapterActions/Execute.cs b/File_Adapter/AdapterActions/Execute.cs
index 52d2bfa9..d40d45f5 100644
--- a/File_Adapter/AdapterActions/Execute.cs
+++ b/File_Adapter/AdapterActions/Execute.cs
@@ -168,3 +168,8 @@ private Output<List<object>, bool> Copy(string source, string target, bool overw
 
 
 
+
+// Touched to exercise the ci-versioning changed-file gate (*.cs). Validation only.
+// Re-trigger for subject-assembly attribution validation.
+// Re-trigger: recursive subject-assembly scan.
+// Re-trigger: unresolvable-cause classification.