React+Lumen

react-lumen.php

<?php
// bootstrap/react.php
// Remember, we need to do first: composer require react/react!

$app = include('app.php');

$host = 'localhost';
$port = 9000;

$reactApp = function (\React\Http\Request $request, \React\Http\Response $response) use ($app, $host, $port) {

    $mapRequest = function(\React\Http\Request $request, $content)
    {
        $method = $request->getMethod();
        $headers = $request->getHeaders();
        $post = array();

        if (isset($headers['Content-Type']) && (0 === strpos($headers['Content-Type'], 'application/x-www-form-urlencoded'))
            && in_array(strtoupper($method), array('POST', 'PUT', 'DELETE', 'PATCH'))
        ) {
            parse_str($content, $post);
        }

        $sf2Request = new Illuminate\Http\Request($request->getQuery(), $post, array(), array(), array(), array(), $content);
        $sf2Request->setMethod($method);
        $sf2Request->headers->replace($headers);
        $sf2Request->server->set('REQUEST_URI', $request->getPath());
        $sf2Request->server->set('SERVER_NAME', explode(':', $headers['Host'])[0]);

        return $sf2Request;
    };


    $mapResponse = function (React\Http\Response $response, Symfony\Component\HttpFoundation\Response $sf2Response)
    {
        $headers = $sf2Response->headers->all();
        $response->writeHead($sf2Response->getStatusCode(), $headers);

        if ($sf2Response instanceof Symfony\Component\HttpFoundation\StreamedResponse) {
            ob_start();
            $sf2Response->sendContent();
            $content = ob_get_contents();
            ob_end_clean();
        }
        else {
            $content = $sf2Response->getContent();
        }

        $response->end($content);
    };

    $mapResponse($response, $app->dispatch($mapRequest($request, null)));
};


$loop = React\EventLoop\Factory::create();
$socket = new React\Socket\Server($loop);
$http = new React\Http\Server($socket);

$http->on('request', $reactApp);
$socket->listen($port);
$loop->run();

@AndrewCarterUK great stuff there. Why don't you add this script to your project? :)