MCP Server Tester

Paste the URL of a live MCP (Model Context Protocol) server using the Streamable HTTP transport, and this tool connects to it, runs the initialize and tools/list calls, and shows exactly which tools it exposes and their descriptions, handy for debugging your own server or checking one before connecting it to an agent.

Your result will appear here.

How the MCP Server Tester works

  1. Paste the URL of your MCP server (Streamable HTTP transport).
  2. The tool sends an initialize call, then tools/list.
  3. Review the server info and the full list of exposed tools.
  4. Fix and re-test until your server responds as expected.

Frequently asked questions

The Streamable HTTP transport (JSON-RPC 2.0 over a single HTTP endpoint). Stdio-based local servers can't be tested from a hosted web tool.

Common causes: the server requires auth headers this tool doesn't send, it only supports stdio, or it isn't a valid MCP endpoint. Check your server logs for the incoming request.

The tool only calls initialize and tools/list, both read-only, standard MCP calls. It doesn't call or execute any of the listed tools.

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