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

JSON formatter • JSON prettifier • JSON beautifier desktop app. Format messy JSON files instantly. Free JSON viewer and organizer for Windows, macOS, Linux.

🔄 A Django middleware to record, track, persist, and replay API requests - enabling state restoration and precise debugging in volatile or reset-prone systems.

A Python library for logging and comparing request-response data to identify differences in headers and payloads between identical endpoints.

Compares API requests to detect failure patterns and surface likely causes with confidence scoring.

Charles Proxy is an HTTP proxy and HTTP monitor that enables developers to view all HTTP and SSL/HTTPS traffic between their machine and the Internet, including requests, responses, and HTTP headers. It supports SSL proxying, bandwidth throttling, AJAX debugging, breakpoints, and traffic recording for API debugging, testing, and development work...

Fiddler by Telerik (Progress Software) is a suite of HTTP debugging proxy tools for capturing, inspecting, modifying, and replaying HTTP and HTTPS traffic between computers. The product family includes Fiddler Everywhere (cross-platform), Fiddler Classic (Windows), and Fiddler Jam (browser-based collaboration tool) for API debugging, performance...

AI-powered tool to analyze and debug API errors instantly

A lightweight CLI HTTP debugging proxy written in Go, designed for developers to inspect, filter, and log HTTP/HTTPS traffic directly from the terminal.

Parse and analyze HTTP Archive (HAR) files via MCP

VS Code extension to replay and compare HTTP API requests from raw text, curl, logs, HAR, and .indus.http files.