Voiden is a developer-first API client with local storage, Git-integrated, all based on markdown + offline support.

Hoppscotch is an open-source API development ecosystem that helps you create and test your API requests saving precious time in development.

Simulate APIs, integrations, and environments at enterprise scale.

Puppeteer is a Node.js library which provides a high-level API to control Chrome/Chromium over the DevTools Protocol.

API Testing Platform that automatically generates unit test cases with dependency mocks from API calls

Bruno is a Fast and Git-Friendly Opensource API client, aimed at revolutionizing the status quo represented by Postman, Insomnia and similar tools out there.