HOOKS Validação de token

Hoks.php

<?php
$token_list = array('_4as82-6assda79sasg_da7s39sa3f32ar6rta' => true,'s796as7dafsdf67d60s9s_df7das67d-796f' => false);
$app->hook(
    'slim.before.router',
    function () use ($app, $token_list) {
        $req = $app->request();
        $current_path = $req->getPathInfo();
        if (!empty($current_path) && $current_path != '/') {
            $access_token = $req->get('access_token');
            if (!isset($token_list[$access_token]) || $token_list[$access_token] !== true) {
                $app->render(
                    'default.php',
                    array('message' => 'O token de acesso fornecido é invalido'),
                    400
                );
                $app->stop();
            }
        }
    }
);