REST APIs are the definition of modern web development. While they are easy to build in just about any modern framework, most PHP developers choose to use Lumen/Laravel or Symfony. These frameworks make it easy to handle complex issues like authentication/authorization, request validation, data transformation, filters, rate throttling, complex endpoints with sub-resources, and API documentation.
A complex framework isn’t necessarily needed to build a secure API. In this post, you’ll build a simple REST API in PHP from scratch. You’ll secure your API with Okta by implementing the Client Credentials Flow.