Personally I use Chrome’s Postman extension to test APIs during development. Then once everything is working properly, the set of API requests I have on Postman during development also work as “documentation” that I export and save (because it support adding notes to requests, scripting for tests, exporting the API requests directly as code to a lot of languages/tools, easy to organize API endpoints into groups, etc). I understand it is not *documentation* exactly, but should be more than enough for a developer to pick up and work with.