Postman

Postman provides an interactive workspace for sending API requests and examining the responses returned by a service. Developers can organize requests into collections, use variables for different environments and add scripts that check behavior automatically. This creates a path from exploring an unfamiliar endpoint to maintaining repeatable tests, with documentation kept close to the requests it describes. Originally a Chrome extension, Postman expanded into a platform with shared workspaces and broader API development tools.

Mock servers let teams simulate responses before an implementation is ready, while monitors run checks on a schedule. Private API networks help organizations make internal APIs discoverable, and Flows supports visual workflows. It suits developers, testers and technical writers who need to collaborate around an API, with advanced governance and team capabilities depending on the offering.