Open-source native macOS HTTP debugging proxy — intercept HTTPS, inspect APIs, mock responses, debug WebSocket & GraphQL. Community-driven. For developers, by developers.

MCP server enabling agents to debug HTTP requests better (using powhttp)

Debugging proxy made for web developers

Proxyman is a modern, native macOS app for HTTP/HTTPS debugging proxy with advanced features for API development and testing.

Whistle is a cross-platform HTTP, HTTPS, HTTP/2, WebSocket, and TCP debugging proxy built on Node.js. It enables developers to inspect, intercept, modify, and replay network traffic through a rule-based configuration system with a built-in web UI.

Scripts to help with debugging apps (especially iOS apps) using OWAZP ZAP

Dev Proxy is a Microsoft command-line tool for simulating, testing, and debugging API interactions during development.