Slim Framework builds on the PSR-7 HTTP message interfaces and provides useful features such as routing, and a DI container. It's lightweight and so is an ideal platform for building APIs. We'll look at how to use Slim as the basis for a fully featured API. We'll cover the key concepts around HTTP request-response resource APIs including handling content type and status codes, authentication and also returning errors appropriately. By the end of the session, you'll be able to build a Slim API.