Dac Chartrand has written up a post to his site showing you how to create a simple REST API with Opulence, a PHP framework that bills itself as a "modern framework for modern PHP".

This tutorial will show you how to code a simple JSON API using Opulence PHP. We will install Opulence’s skeleton project using composer, then create a ‘user’ database entity, and finally we will match CRUD (Create, Read, Update, Delete) to POST, GET, PUT, and DELETE.

The start of the tutorial helps you get a new Opulence project set up and running including updating the configuration for content type handling and the database connection details. With that set up he moves into the code creating the "User" entity and its matching classes. He builds out the controller, selecting a REST controller from the options and builds out all methods needed for the CRUD user operations. The tutorial finishes with a bit of testing information so you can see the framework in action.