Using PHP-PM to run PHP code without a framework

MyHandler.php

<?php

namespace MyApp;

use PHPPM\Bootstraps\ApplicationEnvironmentAwareInterface;
use Psr\Http\Message\ServerRequestInterface;
use RingCentral\Psr7\Response;

class MyHandler implements ApplicationEnvironmentAwareInterface {
    public function __construct() {
        // Application bootstrapping code goes here
    }

    public function initialize($appenv, $debug) {
        // Environment-aware bootstrapping happens here.
        // $appenv and $debug will match what is passed from the
        // config file or command-line arguments
    }

    public function __invoke(ServerRequestInterface $request) {
        $response = new Response(200, [], 'Hello World');
        return $response;
    }
}

ppm.json

{
    "bridge": "PHPPM\\Bridges\\InvokableMiddleware",
    "bootstrap": "MyApp\\MyHandler",
    "host": "..."
}