web/public/api/race/baton.php

<?php $app = require '../../../app/inc.php';

$baton_reader = $app->model('BatonReader');

$cardnumber = (string)filter_input(INPUT_GET, 'cardnumber');

$app->api(
    $baton_reader->receive(
        $cardnumber,
        $app->config['baton_cooldown']
    )
);