Apiary.io is a service to design and test APIs.
“Collaborative design, instant API mock, generated documentation, integrated code samples, debugging and automated testing.”
With Apiary you can create a request/response in less than 1 minute. For do that it uses Blueprint syntax, a documentation is created automatically, so you can use it for documentate your projects.
You can use a ‘mock server’ to test your APIs on the way. That is perfect for continuous workflow, you can design your API as needed while work in front-end stuff. Also there is a traffic inspector that let you control whats happening below.
Here some API examples builded with Apiary.io: