This video covers the other side of creating APIs – when you are ready to test your client-side calls to an API but the server-side code is not ready yet.
Postman allows you to create Mock Servers that you can use to create documentation as well as to generate test data for your client-side AJAX calls.
Code GIST: https://gist.github.com/prof3ssorSt3v3/e3c12f131133ba1e2003d1f4a394bb7b
Other Postman videos
https://www.youtube.com/watch?v=z0MimkXIvE8 – writing automated tests in Postman
https://www.youtube.com/watch?v=t5n07Ybz7yI – Intro to Postman