Verifica copertura su WordPress: plugin o snippet PHP

// functions.php — shortcode + proxy (chiave in wp-config.php:
// define('NETCOV_API_KEY', getenv('NETCOV_API_KEY'));)
add_shortcode('netcov_form', function () {
  return '<form id="ncov"><input name="city" placeholder="Comune">'
    . '<input name="address" placeholder="Via e numero civico">'
    . '<button>Verifica copertura</button><div id="ncov-out"></div></form>';
});

add_action('rest_api_init', function () {
  register_rest_route('netcov/v1', '/coverage', [
    'methods' => 'GET',
    'callback' => function ($req) {
      $city = sanitize_text_field($req['city'] ?? '');
      $address = sanitize_text_field($req['address'] ?? '');
      if ($city === '' || $address === '') {
        return new WP_Error('bad_request', 'city e address richiesti', ['status' => 400]);
      }
      $cache_key = 'netcov_' . md5($city . '|' . $address);
      if (false !== ($hit = get_transient($cache_key))) {
        return $hit;
      }
      $r = wp_remote_get('https://api.netcov.io/coverage/italy?' . http_build_query(
        ['address' => $address . ', ' . $city, 'limit' => 8]
      ), ['headers' => ['Authorization' => 'Bearer ' . NETCOV_API_KEY], 'timeout' => 10]);
      $code = wp_remote_retrieve_response_code($r);
      $body = json_decode(wp_remote_retrieve_body($r), true);
      if ($code < 200 || $code >= 300 || !is_array($body)) {
        return new WP_Error('netcov_error', 'Servizio non disponibile, riprova', ['status' => 502]);
      }
      set_transient($cache_key, $body, HOUR_IN_SECONDS);
      return $body;
    },
    // Solo visitatori loggati OPPURE aggiungi throttle per IP
    // (vedi il plugin ufficiale per l'implementazione completa).
    'permission_callback' => 'is_user_logged_in',
  ]);
});