I built a CLI inspector for MCP servers

I run a custom MCP server with 100+ tools. Every time I added a tool or changed a schema, my only options were reading the source or wiring up a test client. So I built mcpcat — four commands, ~250 lines of Python. # See what a server exposes mcpcat tools http://localhost:8100/mcp # Inspect a specific tool's schema mcpcat inspect http://localhost:8100/mcp cortex_signal # Call a tool directly mcpcat call http://localhost:8100/mcp health # Check if a server is alive mcpcat ping http://localhost:8100/mcp The first version only supported the old SSE transport. It hung on my own server because I use streamable HTTP. Now it auto-detects both. If you're building or consuming MCP servers and want something like curl but for MCP, give it a try: pip install git+https://github.com/AlexlaGuardia/MCPcat.git I wrote a longer post about the build process and the transport detection bug here: alexlaguardia.dev/writing/mcpcat Built with Python, Typer, httpx, and Rich. MIT licensed. PRs welcome.