MCP tool-call inspector
Inspect tool calls, responses, and request history.
Runs in your browser
OutputText · 0 bytes
Your result will appear hereAdd your input, choose the options and run the tool.
Your input stays on this device. Nothing is uploaded or saved.
About MCP tool-call inspector
Pair requests and responses from a pasted MCP JSON-RPC trace and inspect tool calls, failures and unmatched messages.
When to use it
Understand which MCP tool call produced an error or is missing its response.
[{"jsonrpc":"2.0","id":1,"method":"tools/list"},{"jsonrpc":"2.0","id":1,"result":{"tools":[]}}]How to use it
- Paste a JSON array of sent and received JSON-RPC messages.
- Run the inspection.
- Review calls, arguments, results and unmatched IDs.
Limits & privacy
Up to 200 messages and 64 KiB. This is an offline trace inspector; it does not connect to a server or verify tool behavior. Numeric and string IDs are distinct. No timestamps or duration are inferred.
Use this tool from the API reference or connect through the SDK, CLI, SSH, or MCP. Hosted calls share your plan allowances.