MCP Inspector
The MCP Inspector is an interactive developer tool used to test and debug MCP servers in isolation before integrating them into a full host application.
Quick Start
Run via npx (requires Node.js):
npx @modelcontextprotocol/inspector <command> <args>
Examples
- Inspecting a python Server:
npx @modelcontextprotocol/inspector uv run server.py - Inspecting an npm Package:
npx -y @modelcontextprotocol/inspector npx @modelcontextprotocol/server-filesystem /path/to/test
Core Features
- Resources Tab: Browse all exposed resources and inspect their content/metadata.
- Prompts Tab: Test parameterized templates with custom arguments.
- Tools Tab: Manually trigger tool calls and view JSON execution results.
- Notifications Pane: Real-time stream of server logs and protocol events.
Development Workflow
- Launch: Start the Inspector with your server command.
- Verify: Check that all tools/resources are listed with correct schemas.
- Iterate: Modify server code, rebuild, and use the "Reconnect" button in the Inspector UI.
- Edge Cases: Input invalid arguments to ensure your server handles errors gracefully according to the protocol.
References
- Source:
00_Raw/mcp/MCP Inspector.md - mcp-debugging
- mcp-server-development