About this project

Reticle calls itself "the Wireshark for the Model Context Protocol." It is a proxy plus desktop UI that intercepts, visualizes, and profiles MCP JSON-RPC traffic between an LLM client and MCP servers. Key capabilities: - Inspect raw JSON-RPC messages (requests, notifications, responses) - Instantly correlate request ↔ response pairs - Profile latency and estimate token usage - Capture server stderr and crash output - Record sessions and export logs Supported transports include stdio, Streamable HTTP, WebSocket, and HTTP/SSE. Three CLI commands cover the main workflows: `mcp-reticle run` wraps stdio MCP servers for inspection, `mcp-reticle proxy` reverse-proxies HTTP/SSE/WebSocket transports, and `mcp-reticle ui` launches the desktop interface. A log-only mode is available without the UI, and a headless `daemon` command acts as a telemetry hub. Installation is via npm, pip, or Homebrew, or built from source using `just build`. Full documentation, including architecture, security guidance, client configuration, troubleshooting, and export formats, is maintained in the GitHub Wiki. The tool treats recordings and exports as sensitive artifacts because they may contain tool inputs and outputs. The project is MIT-licensed.