diff --git a/.github/workflows/release-traceability.yml b/.github/workflows/release-traceability.yml
index cdc7343..5549813 100644
--- a/.github/workflows/release-traceability.yml
+++ b/.github/workflows/release-traceability.yml
@@ -47,7 +47,13 @@ jobs:
     runs-on: ubuntu-latest
     needs: deploy
     steps:
+      - uses: actions/checkout@v4
+
+      - name: Verify traceability script cases
+        run: bash ./scripts/github-actions/test-validate-release-traceability.sh
+
       - name: Validate runtime traceability
         env:
           SERVICE_IMAGE_REF: ${{ needs.build.outputs.service_image_ref }}
+          RUNTIME_PING_URL: https://accounts.svc.plus/api/ping
         run: bash ./scripts/github-actions/validate-release-traceability.sh
diff --git a/docs/api.md b/docs/api.md
index 3c4f254..e0f3e76 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -9,6 +9,14 @@ upstream and downstream interfaces it depends on.
 
 Returns the runtime image identity exposed by the running container.
 
+Validation notes:
+
+- release traceability checks this endpoint with `GET`, not `HEAD`
+- `accounts.svc.plus/api/ping` is the current production validation target for
+  release identity
+- empty `image`, `tag`, `commit`, or `version` means runtime image identity was
+  not injected correctly and should fail deployment validation
+
 Example response:
 
 ```json
diff --git a/docs/release-traceability.md b/docs/release-traceability.md
index faeddff..dc86560 100644
--- a/docs/release-traceability.md
+++ b/docs/release-traceability.md
@@ -16,12 +16,22 @@ release identity.
 - Build must produce `service_image_ref` only from the full `GITHUB_SHA`.
 - Deploy must consume `service_image_ref` and pass it through as the runtime
   image identity.
+- Validate must use `GET https://accounts.svc.plus/api/ping`.
 - Validate must derive `tag` and `commit` from `service_image_ref` and compare
   them against `/api/ping`.
+- Validate must fail when runtime `image`, `tag`, `commit`, or `version` is
+  empty.
+- Validate must compare `version` against the derived full commit, not a
+  synthetic fallback.
 
 ## External playbook alignment
 
 The external `playbooks/deploy_billing_service.yml` playbook should accept
 `IMAGE_REF` (or an equivalent full image reference variable), derive any
 repo/tag helpers from it, and inject `IMAGE=<full image ref>` into the running
-container environment.
+container environment for the service exposed through
+`https://accounts.svc.plus/api/ping`.
+
+If `accounts.svc.plus/api/ping` keeps returning empty runtime metadata, treat
+that as a deployment contract failure: the runtime did not receive the full
+`IMAGE` value and release traceability is broken.
diff --git a/scripts/github-actions/test-validate-release-traceability.sh b/scripts/github-actions/test-validate-release-traceability.sh
new file mode 100644
index 0000000..a113f22
--- /dev/null
+++ b/scripts/github-actions/test-validate-release-traceability.sh
@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_root="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+script_path="${repo_root}/scripts/github-actions/validate-release-traceability.sh"
+tmpdir="$(mktemp -d)"
+trap 'rm -rf "${tmpdir}"' EXIT
+
+service_image_ref="ghcr.io/x-evor/billing-service:sha-0123456789abcdef0123456789abcdef01234567"
+
+run_success_case() {
+  local response_path="${tmpdir}/success.json"
+  cat > "${response_path}" <<'EOF'
+{"image":"ghcr.io/x-evor/billing-service:sha-0123456789abcdef0123456789abcdef01234567","tag":"sha-0123456789abcdef0123456789abcdef01234567","commit":"0123456789abcdef0123456789abcdef01234567","version":"0123456789abcdef0123456789abcdef01234567","status":"ok"}
+EOF
+
+  SERVICE_IMAGE_REF="${service_image_ref}" \
+  RUNTIME_PING_URL="file://${response_path}" \
+  bash "${script_path}"
+}
+
+run_failure_case() {
+  local name="$1"
+  local response_path="$2"
+
+  if SERVICE_IMAGE_REF="${service_image_ref}" \
+    RUNTIME_PING_URL="file://${response_path}" \
+    bash "${script_path}"; then
+    echo "expected ${name} to fail" >&2
+    exit 1
+  fi
+}
+
+cat > "${tmpdir}/empty.json" <<'EOF'
+{"image":"","tag":"","commit":"","version":"","status":"ok"}
+EOF
+
+cat > "${tmpdir}/mismatch.json" <<'EOF'
+{"image":"ghcr.io/x-evor/billing-service:sha-fedcba98765432100123456789abcdef01234567","tag":"sha-fedcba98765432100123456789abcdef01234567","commit":"fedcba98765432100123456789abcdef01234567","version":"fedcba98765432100123456789abcdef01234567","status":"ok"}
+EOF
+
+run_success_case
+run_failure_case "empty runtime metadata" "${tmpdir}/empty.json"
+run_failure_case "mismatched runtime metadata" "${tmpdir}/mismatch.json"
diff --git a/scripts/github-actions/validate-release-traceability.sh b/scripts/github-actions/validate-release-traceability.sh
index b1bb474..112ab13 100644
--- a/scripts/github-actions/validate-release-traceability.sh
+++ b/scripts/github-actions/validate-release-traceability.sh
@@ -2,11 +2,21 @@
 set -euo pipefail
 
 service_image_ref="${SERVICE_IMAGE_REF:?SERVICE_IMAGE_REF is required}"
+runtime_ping_url="${RUNTIME_PING_URL:?RUNTIME_PING_URL is required}"
 tag="${service_image_ref##*:}"
 commit="${tag#sha-}"
 
-curl -fsS "https://billing-service.example.com/api/ping" | jq -e \
+curl -fsS "${runtime_ping_url}" | jq -e \
   --arg image "${service_image_ref}" \
   --arg tag "${tag}" \
   --arg commit "${commit}" \
-  '.image == $image and .tag == $tag and .commit == $commit'
+  '
+  (.image | type == "string" and length > 0) and
+  (.tag | type == "string" and length > 0) and
+  (.commit | type == "string" and length > 0) and
+  (.version | type == "string" and length > 0) and
+  .image == $image and
+  .tag == $tag and
+  .commit == $commit and
+  .version == $commit
+  ' >/dev/null