{ "pr": 917, "title": "Duplicate prevention failed for simultaneous requests", "run": { "pr": 917, "title": "Spec: mcp-server-core", "run_id": "mcp-server-core-20260623T174318286059", "mode": "spec", "created": "2026-06-23T17:43:18.340714+00:00", "merged": "2026-06-23T19:55:11+00:00", "agent": "codex", "chain_runs": 1, "has_implement_event": true, "elapsed_hours": 2.197960912777778, "implementation_to_merge_hours": 2.192662828611111, "recorded_phase_hours": 2.1979127069444444, "churn": 2052, "files": 15, "direct_signals": 0, "broad_signals": 0, "review_rejected": true, "review_rejections": 4, "gates_rejected": false }, "merge_sha": "06b8f934bb0b12f9fc8551c794ebe291a1845033", "selected_review": { "attempt_number": 1, "findings": [ { "body": "The idempotency lookup is performed and closed before the REST enqueue, and the idempotency row is only inserted after `/api/runs` or `/api/runs/sweep` has already accepted a run. Two concurrent requests with the same `(service_key_id, tool_name, idempotency_key)` can both miss the lookup, both enqueue, and only then race on `create_mcp_idempotency_record`. That violates the spec requirement that same-payload idempotent repeats do not enqueue a duplicate run. Reserve or lock the idempotency tuple before calling the REST enqueue, or otherwise make the lookup/enqueue/record sequence atomic.", "confidence": 0.93, "end_line": 283, "file": "api/mcp/router.py", "id": "F1", "severity": "P1", "start_line": 245, "title": "Concurrent idempotent enqueues can create duplicate runs" } ], "reviewed_at": "2026-06-23T11:21:00Z", "reviewed_base_sha": "6f4e96b72108ed11ec0980227c71a2e2a4989e7f", "reviewed_head_sha": "b992090dcc2ab5d4931c0eb4cc47c9a74e2441d2", "reviewer_agent": "codex", "reviewer_role": "independent_reviewer", "source_check_name": "review-decision-gate", "source_check_url": "private repository PR #917", "status": "request_changes", "summary": "Found blocking idempotency correctness issues. The MCP surface is broadly present, but the enqueue idempotency contract is not safe under concurrency or TTL expiry, and a telemetry acceptance criterion is also not implemented." }, "final_approval": { "attempt_number": 5, "findings": [], "reviewed_at": "2026-06-23T19:43:00Z", "reviewed_base_sha": "6f4e96b72108ed11ec0980227c71a2e2a4989e7f", "reviewed_head_sha": "7b8d9711dbf16fc2928d1da9657987c429985209", "reviewer_agent": "codex", "reviewer_role": "independent_reviewer", "source_check_name": "review-decision-gate", "source_check_url": "private repository PR #917", "status": "approved", "summary": "No blocking correctness, security, acceptance-criteria, or test issues found in the PR diff." }, "merged_excerpts": [ { "file": "api/mcp/router.py", "start_line": 240, "end_line": 306, "language": "python", "text": "async def _enqueue_with_idempotency(\n request: Request,\n actor: McpActor,\n *,\n tool_name: str,\n rest_path: str,\n payload: dict[str, Any],\n idempotency_key: str | None,\n) -> dict[str, Any]:\n if not idempotency_key:\n response = await _rest_call(request, actor, \"POST\", rest_path, json_body=payload)\n _raise_for_rest_error(response)\n return _enqueue_envelope(response.json(), idempotency_key=None)\n\n payload_hash = repository.payload_sha256(payload)\n settings = get_settings()\n conn = repository.get_connection(str(get_settings().database_url))\n try:\n with conn.transaction():\n await asyncio.to_thread(\n repository.lock_mcp_idempotency_key,\n conn,\n service_key_id=actor.service_key_id,\n tool_name=tool_name,\n idempotency_key=idempotency_key,\n )\n record = await asyncio.to_thread(\n repository.get_mcp_idempotency_record,\n conn,\n service_key_id=actor.service_key_id,\n tool_name=tool_name,\n idempotency_key=idempotency_key,\n ttl_seconds=settings.mcp_idempotency_ttl_seconds,\n )\n if record is not None:\n if record.payload_sha256 != payload_hash:\n raise McpToolError(\n \"idempotency_key_payload_mismatch\",\n \"The idempotency key was reused with different inputs.\",\n )\n envelope = dict(record.envelope)\n envelope[\"_mcp_outcome\"] = \"idempotent_replay\"\n return envelope\n\n response = await _rest_call(request, actor, \"POST\", rest_path, json_body=payload)\n _raise_for_rest_error(response)\n envelope = _enqueue_envelope(response.json(), idempotency_key=idempotency_key)\n try:\n await asyncio.to_thread(\n repository.create_mcp_idempotency_record,\n conn,\n service_key_id=actor.service_key_id,\n tool_name=tool_name,\n idempotency_key=idempotency_key,\n payload_sha256=payload_hash,\n run_id=envelope[\"run_id\"],\n envelope=envelope,\n ttl_seconds=settings.mcp_idempotency_ttl_seconds,\n )\n except repository.McpIdempotencyConflict as exc:\n raise McpToolError(\n \"idempotency_key_payload_mismatch\",\n \"The idempotency key was reused with different inputs.\",\n ) from exc\n return envelope\n finally:\n conn.close()" }, { "file": "tests/test_mcp_core.py", "start_line": 517, "end_line": 543, "language": "python", "text": "async def test_concurrent_enqueue_idempotency_does_not_duplicate_rest_enqueue(monkeypatch, mcp_client):\n client, database_url, _app = mcp_client\n _owner_user_id, _service_key_id, token = _seed_user_and_service_key(database_url)\n calls = 0\n\n async def fake_rest_call(request, actor, method, path, *, json_body=None):\n nonlocal calls\n calls += 1\n await asyncio.sleep(0.05)\n return httpx.Response(\n 202,\n json={\"id\": 88, \"status\": \"queued\", \"run_kind\": \"simulation\", \"run_limit\": None},\n )\n\n mcp_router = importlib.import_module(\"api.mcp.router\")\n\n monkeypatch.setattr(mcp_router, \"_rest_call\", fake_rest_call)\n args = {\"config_name\": \"baseline\", \"idempotency_key\": \"concurrent\"}\n first, second = await asyncio.gather(\n _rpc(client, token, \"tools/call\", {\"name\": \"run_simulation\", \"arguments\": args}),\n _rpc(client, token, \"tools/call\", {\"name\": \"run_simulation\", \"arguments\": args}),\n )\n assert first.status_code == 200\n assert second.status_code == 200\n assert first.json()[\"result\"][\"structuredContent\"][\"run_id\"] == 88\n assert second.json()[\"result\"][\"structuredContent\"][\"run_id\"] == 88\n assert calls == 1" } ], "verification": "Inspected recorded finding, final approval, gate histories and merged implementation/test. Historical tests were not rerun.", "gates": { "spec_id": "mcp-server-core", "gates": { "e2e": { "attempts": 5, "history": [ { "attempt": 1, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:20:21.790686+00:00" }, { "attempt": 2, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:40:55.571050+00:00" }, { "attempt": 3, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:59:43.760567+00:00" }, { "attempt": 4, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T19:20:58.536084+00:00" }, { "attempt": 5, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T19:40:49.445235+00:00" } ], "last_command": "make e2e", "last_status": "passed" }, "lint": { "attempts": 5, "history": [ { "attempt": 1, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:18:12.730594+00:00" }, { "attempt": 2, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:38:50.658113+00:00" }, { "attempt": 3, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T18:57:38.134293+00:00" }, { "attempt": 4, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T19:18:50.803313+00:00" }, { "attempt": 5, "error_count": null, "failed_count": null, "failed_tests": null, "failure_fingerprint": "", "passed_count": null, "status": "passed", "timestamp": "2026-06-23T19:38:42.985216+00:00" } ], "last_command": "make lint", "last_status": "passed" }, "test": { "attempts": 5, "history": [ { "attempt": 1, "error_count": 0, "failed_count": 0, "failed_tests": [], "failure_fingerprint": "", "passed_count": 3686, "status": "passed", "timestamp": "2026-06-23T18:18:12.727675+00:00" }, { "attempt": 2, "error_count": 0, "failed_count": 0, "failed_tests": [], "failure_fingerprint": "", "passed_count": 3689, "status": "passed", "timestamp": "2026-06-23T18:38:50.655384+00:00" }, { "attempt": 3, "error_count": 0, "failed_count": 0, "failed_tests": [], "failure_fingerprint": "", "passed_count": 3691, "status": "passed", "timestamp": "2026-06-23T18:57:38.131449+00:00" }, { "attempt": 4, "error_count": 0, "failed_count": 0, "failed_tests": [], "failure_fingerprint": "", "passed_count": 3693, "status": "passed", "timestamp": "2026-06-23T19:18:50.800519+00:00" }, { "attempt": 5, "error_count": 0, "failed_count": 0, "failed_tests": [], "failure_fingerprint": "", "passed_count": 3696, "status": "passed", "timestamp": "2026-06-23T19:38:42.982271+00:00" } ], "last_command": "make test", "last_status": "passed" } } } }