Extending WordPress REST API

There are no answers here yet, but atleast we ended up using a combination of WP REST API and WP OAuth Server.

The WP REST API was really easy to work with, as it provided a common framework to respond to HTTP requests. I found it similar to ASP.NET Web API, as that’s the framework I’m more familiar with. It also gave us a framework (MVC) to create a HTTP response, and it serialized all our objects to JSON, like you can expect.

The WP OAuth Server helped us achieve OAuth 2 authentication, as the API needs to be protected somehow. Also, an app is going to integrate against this API, and it makes sense to use an OAuth flow with user credentials etc. One caveat here is OAuth 2 requires HTTPS.