Sooner or later, every application needs an API. It will need to integrate with your microservices, peer client service, or your new front-end mobile and web apps. With JSONAPI, and JSONAPI-Resources, building your API platform is easy. You just add your own application magic. Along with one of these JSONAPI Client Libraries, your application can rule the world.
There is a lot of background that I won’t be covering. I’ll assume you are familiar with HTTP, REST, JSON, Rails Routing, and have some basic Rails experience. I’m writing the overview I wish I had when I started. Not all examples are complete or polished, but should be far enough along so you can “load” the problem into your head when starting work on your API.