{"record":{"id":"939d4f01b095b7c7","repo":"rohitg00/ai-engineering-from-scratch","slug":"32602-939d4f","errorCode":"-32602","errorMessage":"params must be an object","messagePattern":"params must be an object","errorType":"error_code","errorClass":"RpcProblem","httpStatus":null,"severity":"error","filePath":"phases/13-tools-and-protocols/07-building-an-mcp-server/code/main.py","lineNumber":161,"sourceCode":"    result = {\n        \"resultType\": \"complete\",\n        **payload,\n        \"_meta\": {SERVER_INFO_KEY: SERVER_INFO.copy()},\n    }\n    if ttl_ms is not None:\n        result[\"ttlMs\"] = ttl_ms\n        result[\"cacheScope\"] = cache_scope\n    return result\n\n\ndef validate_request(message: dict[str, Any]) -> None:\n    if message.get(\"jsonrpc\") != \"2.0\" or not isinstance(message.get(\"method\"), str):\n        raise RpcProblem(-32600, \"Invalid Request\")\n    if \"id\" in message and type(message[\"id\"]) not in (int, str):\n        raise RpcProblem(-32600, \"id must be a string or integer\")\n    params = message.get(\"params\")\n    if not isinstance(params, dict):\n        raise RpcProblem(-32602, \"params must be an object\")\n    meta = params.get(\"_meta\")\n    if not isinstance(meta, dict):\n        raise RpcProblem(-32602, \"params._meta is required\")\n    requested = meta.get(VERSION_KEY)\n    if not isinstance(requested, str):\n        raise RpcProblem(-32602, f\"{VERSION_KEY} is required\")\n    if requested not in SUPPORTED_VERSIONS:\n        raise RpcProblem(\n            -32022,\n            \"Unsupported protocol version\",\n            {\"requested\": requested, \"supported\": SUPPORTED_VERSIONS.copy()},\n        )\n    if not isinstance(meta.get(CAPABILITIES_KEY), dict):\n        raise RpcProblem(-32602, f\"{CAPABILITIES_KEY} is required\")\n    client_info = meta.get(CLIENT_INFO_KEY)\n    if client_info is not None and (\n        not isinstance(client_info, dict)\n        or not isinstance(client_info.get(\"name\"), str)","sourceCodeStart":143,"sourceCodeEnd":179,"githubUrl":"https://github.com/rohitg00/ai-engineering-from-scratch/blob/39ea8a1c6d0b61f071226eff7ede4d4105fed820/phases/13-tools-and-protocols/07-building-an-mcp-server/code/main.py#L143-L179","documentation":"Error \"params must be an object\" thrown in rohitg00/ai-engineering-from-scratch.","triggerScenarios":"Thrown at phases/13-tools-and-protocols/07-building-an-mcp-server/code/main.py:161 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"39ea8a1c6d0b61f071226eff7ede4d4105fed820","analyzedAt":"2026-08-26T03:13:46.626Z","schemaVersion":2},"datasetVersion":"2026-08-26T07:17:17.940Z"}