Pony.fm/app/Http/Controllers/ApiControllerBase.php

<?php

namespace Poniverse\Ponyfm\Http\Controllers;

use Response;

abstract class ApiControllerBase extends Controller
{
    protected function execute($command)
    {
        if (!$command->authorize()) {
            return $this->notAuthorized();
        }

        $result = $command->execute();
        if ($result->didFail()) {
            return Response::json([
                'message' => 'Validation failed',
                'errors' => $result->getValidator()->messages()->getMessages()
            ], 400);
        }

        return Response::json($result->getResponse(), 200);
    }

    public function notAuthorized()
    {
        return Response::json(['message' => 'You may not do this!'], 403);
    }

    public function notFound($message)
    {
        return Response::json(['message' => $message], 403);
    }
}