Slim-Psr7 VS Slim

Slim PSR7: a strict PSR-7 implementation used by Slim

Slim is a micro PHP framework used for web development with 11.7k stars and 2k forks on GitHub. It has a simple and intuitive API development process. It is a micro-framework, meaning you only get a minimum of support for HTTP requests and forwarding requests to appropriate controllers. So the question is, why should you choose a micro-framework? Because it offers you flexibility and high extensibility.

Slim 4, a minimalistic PHP micro-framework, offers middleware support to easily add CORS headers. Middleware in Slim acts like a series of layers through which your app sends a request. One such layer can be responsible for adding CORS headers.

SlimPHP 3 Skeleton app shows this as well: https://github.com/slimphp/Slim-Skeleton/blob/3.1.8/public/index.php

How hard did you look? There are plenty out there. FastRoute, Phroute, based on FastRoute, with basic middleware, League/Route - routing with middleware, using FastRoute, PSR 7 & 15, Slim Framework, at it's core, it like League/Route, etc. None of these require a full framework to use.

You can have the container call in a config folder with a file called dependencies or how ever you want. A few existing examples of this is here - Slim calls this app/dependencies in this skeleton project and Odan's Skeleton has this as config/container in their project.

Maybe use this if you don't like to dive into bigger frameworks: https://www.slimframework.com/

Go for Slim: https://www.slimframework.com/