Show HN: Reticle – Debug MCP Tool Calls from Claude/Cursor (Rust) (github.com)

Reticle, a new debugging tool for the Model Context Protocol (MCP), offers an innovative solution for developers working with large language models (LLMs) like Claude and Cursor. Unlike traditional debugging methods that leave significant gaps in visibility, Reticle captures and visualizes JSON-RPC traffic in real time, providing deep insights into requests, responses, and server performance metrics without introducing latency. Features such as raw message inspection, latency profiling, and error tracing empower developers to quickly identify bottlenecks and failures in their systems, making it similar to a “Wireshark for LLMs.” This tool addresses several critical pain points, including silent failures and cryptic error messages that hinder efficient debugging. By enabling multi-session support and session tagging, Reticle enhances the developer experience and allows for more organized monitoring of multiple MCP servers simultaneously. Built with modern Rust and TypeScript technologies, it ensures high throughput and low memory consumption, proving essential for developers who manage complex AI interactions. Overall, Reticle represents a significant advancement in LLM debugging, pushing the boundaries of what developers can achieve in AI and ML contexts.