PSR-15 is a standard describing server request handlers and middlewares for PHP.
In some cases Twirp might not be the primary receiver of requests or simply you might want to add some extra logic to the HTTP flow (for example attaching some headers to the Twirp context). Either way, PSR-15 has a great ecosystem around it which helps you with both cases.
When a Twirp service is not the primary target of requests in an application, you probably want to register it as a sort of “controller” and handle the routing outside of it.
Given an imaginary router, you might write some code like this:
<?php $server = new \Twitch\Twirp\Example\HaberdasherServer(new \Twirphp\Example\Haberdasher()); $router->register('POST', \Twitch\Twirp\Example\HaberdasherServer::PATH_PREFIX, [$server, 'handle']);
The code above registers the Twirp server as a request handler for it’s path prefix in the router. The syntax of course can be different based on the router implementation.