Fast application

To build a simple Web application, it’s possible to use the FastApplication class, which is a route handlers container.

FastApplication::listen is used to register a route handler.

This is a basic example of FastApplication:

use Piko\FastApplication;
use Psr\Http\Message\ServerRequestInterface;

require 'vendor/autoload.php';

$app = new FastApplication();

$app->listen('GET', '/', function(ServerRequestInterface $request) {
	return 'App home';

$app->listen('GET', '/user/:name', function(ServerRequestInterface $request) {
	$name = $request->getAttribute('name');
	return "Hello $name";


Customize the response

The request handler callback can return either a string or a Psr\Http\Message\ResponseInterface object.

FastApplication::createResponse is an helper to create the response object.

With the response object, it’s possible, for instance, to inject headers:

$app->listen(['GET', 'POST'], '/user/:name', function(ServerRequestInterface $request) {

    $user = [
        'name' => $request->getAttribute('name')

    $response = FastApplication::createResponse(json_encode($user));

    return $response->withHeader('Content-type', 'application/json');

Custom error handler

By default, exceptions are thrown to the end user but it’s possible to handle these exception using a custom error handler :

use Piko\FastApplication;
use Psr\Http\Server\RequestHandlerInterface;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;

require 'vendor/autoload.php';

class ErroHandler implements RequestHandlerInterface
    public function handle(ServerRequestInterface $request): ResponseInterface
        $message = 'Page not Found';

        if (getenv('APP_ENV') == 'dev') {
            $exception = $request->getAttribute('exception');
            $message = $exception->getMessage();

        return FastApplication::createResponse($message);

$app = new FastApplication([
    'errorHandler' => new ErroHandler()

// ...