AI Developer Tools
mcpsnoop
A transparent proxy that shows every real tool call between your AI client and MCP servers, live in your terminal.
mcpsnoop
What is mcpsnoop?
mcpsnoop is a terminal-based debugging tool that sits between your AI client and MCP servers to inspect and replay JSON-RPC tool calls.
mcpsnoop vs Similar AI Tools
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How to use mcpsnoop?
- 1Install via 'go install github.com/kerlenton/mcpsnoop/cmd/mcpsnoop@latest' or 'brew install mcpsnoop'.
- 2Wrap your server command with 'mcpsnoop -- <server>' in your client's MCP config.
- 3Use your client as usual.
- 4Run 'mcpsnoop' to open the live terminal UI.
- 5For streamable HTTP servers, use 'mcpsnoop http --target URL --listen :7000'.
mcpsnoop Key Features
- Live JSON-RPC stream with color-coded requests, responses, errors, and slow calls
- Replay any captured tool call against a fresh isolated server
- Capability inspector showing client and server handshake
- Frame inspector with full pretty-printed JSON and in-frame search
- Hung-call detection with live PENDING timer
- Filter stream by tool, status, direction, kind, ID, or plain text
mcpsnoop Use Cases
- Debugging real-time MCP traffic between AI clients and servers
- Inspecting tool call arguments and responses
- Replaying tool calls for iterative development
- Verifying capability agreements between client and server
mcpsnoop Pricing & Free Credits
mcpsnoop currently operates on a Free model.
This tool is completely free to use
mcpsnoop Pros & Cons
Pros
- Transparent proxy requires no configuration changes
- Live terminal UI with powerful filtering
- Replay functionality for quick iteration
- Works with any MCP server language
Cons
- Pre-1.0 software may have breaking changes
- Only supports MCP protocol traffic
- Requires Go or Homebrew for installation
What is mcpsnoop best for?
- Developers debugging MCP-based AI applications
- Engineers building custom MCP servers or clients