Testing and Debugging with the MCP Inspector
~10 min read
The MCP Inspector is a web-based dashboard, launched automatically in development mode, for browsing tools, exploring resources, and monitoring JSON-RPC traffic before connecting an agent.
Testing and Debugging with the MCP Inspector is a Pro topic
Sign in, then upgrade to Pro or Power to unlock this topic and the full AI Engineering curriculum.
Key points
- •The MCP Inspector is a web-based dashboard, launched automatically in development mode, for inspecting and debugging MCP servers
- •It lets you browse/test tools, explore resources, preview prompts, and watch sampling/notification events interactively
- •It also monitors all JSON-RPC traffic between client and server — the raw protocol messages underlying every interaction
- •The book frames it as the fastest way to verify server capabilities before connecting an agent
- •Testing in the Inspector first isolates 'is my server broken' from 'is my agent using it correctly' — two very different debugging problems