diff --git a/src/lab/observe/from-conformance.ts b/src/lab/observe/from-conformance.ts
index 9c6e686de..9efbf492b 100644
--- a/src/lab/observe/from-conformance.ts
+++ b/src/lab/observe/from-conformance.ts
@@ -130,6 +130,8 @@ function upstreamAdapter(protocol: string): string {
       return "anthropic";
     case "openai-chat":
       return "openai-chat";
+    case "cursor-protobuf":
+      return "cursor-protobuf";
     default:
       throw new Error(`unsupported protocol identity: ${protocol}`);
   }
diff --git a/tests/lab-evidence-ledger.test.ts b/tests/lab-evidence-ledger.test.ts
index 9678c9dd4..caf0f2218 100644
--- a/tests/lab-evidence-ledger.test.ts
+++ b/tests/lab-evidence-ledger.test.ts
@@ -659,6 +659,25 @@ describe("CL-02 projection rebuild determinism", () => {
 });
 
 describe("CL-02 CL-01 integration", () => {
+  test("mcp-core cursor-protobuf result produces protocol evidence", () => {
+    withHome((home) => {
+      const authority = loadCaseAuthority();
+      const caseRecord = discoverScenarios(authority, ["mcp-core"]).find(
+        (c) => c.id === "mcp-core.protocol.namespace-mapping",
+      )!;
+
+      const { event } = observationFromConformanceResult(
+        syntheticPassResult(caseRecord),
+        caseRecord,
+        authority,
+        { configDir: home },
+      );
+
+      expect(event.subject.effectiveAdapter).toBe("cursor-protobuf");
+      expect(event.subject.upstreamProtocol).toBe("cursor-protobuf");
+    });
+  });
+
   test("run → observation → JSONL → replay → SQLite protocol projection", async () => {
     await withHome(async (home) => {
       const authority = loadCaseAuthority();
@@ -1158,4 +1177,4 @@ describe("CL-02 phase-2 review regressions", () => {
       closeTrustedArtifactDir(dir);
     });
   });
-});
\ No newline at end of file
+});