REST API client library for .NET

Postman is an API platform for building and using APIs. Postman simplifies each step of the API lifecycle and streamlines collaboration so you can create better APIs—faster.

Simulate APIs, integrations, and environments at enterprise scale.

Real API Design-first Development Platform Design. Debug. Test. Document. Mock. Build APIs Faster & Together.

Built for developers and testers alike, SoapUI is the only open source tool that covers the entire testing spectrum (functional, security, load, mocking).

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