WordPress REST API has become popular mostly for querying the default routes. However, in reality, it is not just a single API, but the base for a large number of APIs, and in fact, from which you can create your own APIs.

Though the WordPress REST API is adding a useful set of default routes to your site, what is even more awesome is that in service of creating routes, a RESTful API server is generated that is a powerful tool for creating custom APIs.
So, before the time comes when you can’t make a default route do exactly what you want, learn now  to just make your own.

To read the full article, click on this link: http://torquemag.io/adding-custom-routes-wordpress-rest-api/