Best Open Source API Clients

Lightweight, fast, and feature-rich API client for developers. Test, debug, and document APIs with ease in a clean, modern interface.

A modern, user-friendly API client that simplifies API testing and development with a clean interface and powerful features.

Intuitive API client for REST, GraphQL, and gRPC. Debug, test, and collaborate on APIs with ease across platforms.

A modern API client offering local-only data storage, Git integration, plugin extensibility, and multi-protocol support for developers.

A powerful browser extension and desktop app for developers to manipulate network requests, debug APIs, and improve web app testing

Intuitive, user-friendly CLI tool for making HTTP requests, debugging APIs, and testing web services with ease and efficiency.

All-in-one platform for API testing, documentation, and collaboration, simplifying the entire API development lifecycle.

Offline-first API workspace that unifies specs, docs, tests, and mocks in programmable Markdown blocks. Version control everything in plain text files.