MCP server tester
Paste a remote MCP endpoint and find out in seconds whether it speaks the protocol — initialize handshake, server info, and the full tools list. The fastest way to debug "why won't my client connect".
Free tool, fair-use limited (10 tests/hour). HTTPS endpoints only; tokens are never stored.
Building or hosting a server?
The build-an-MCP-server tutorial walks through the current SDK, and the MCP hosting guide covers managed vs self-hosted. Your own business already has an endpoint on BusinessMCP — test it right here with an mcph_ key.
Frequently asked questions
What does this tester actually do?
It speaks the Model Context Protocol to your endpoint over streamable HTTP: an initialize handshake (protocol version, server info, capabilities) followed by tools/list. If both succeed, your server is valid MCP and any compliant client — Claude Desktop, Cursor, the OpenAI ecosystem — should be able to connect.
My server works locally over stdio — can I test it here?
No — this tool tests REMOTE servers over HTTPS. For local stdio servers use the official MCP Inspector (npx @modelcontextprotocol/inspector). To make a local server remotely reachable, deploy it with a streamable-HTTP transport first.
Is my bearer token safe?
The token is used for the two test requests and never stored or logged. Still, best practice applies: use a scoped, revocable key for testing — BusinessMCP keys, for example, can be scoped by access policy so a test key can’t read revenue or contact data.
It says "reachable but no valid JSON-RPC initialize result" — what now?
Common causes: the URL is a website not an MCP endpoint; the server only speaks the older SSE transport (GET-based) rather than streamable HTTP; or a proxy strips POST bodies. Check that POST with Accept: application/json, text/event-stream reaches your MCP handler.