Why is this Drupal services RESTful API not working?
Later of try and try, when read from other tutorial, i make a resource with rest, soap for me is imposible in drupal, i try but without success, you can copy and page this code and modify only the custom module name and hooks.

/**
 * Implements hook_ctools_plugin_api().
 */
function core_custom_webservice_ctools_plugin_api($owner, $api) {
  if ($owner == 'services' &amp;&amp; $api == 'services') {
    return array(
      'version' =&gt; 3,
      'file' =&gt; 'core_custom_webservice.services.inc'
    );
  }
}


function core_custom_webservice_services_resources() {
  $resources = array(
    'webservice_resources' =&gt; array(
      'operations' =&gt; array(
        'retrieve' =&gt; array(
          'help' =&gt; t('Response of webservice'),
          'file' =&gt; array('type' =&gt; 'inc', 'module' =&gt; 'core_custom_webservice', 'name' =&gt; 'core_custom_webservice.resource',),
          'callback' =&gt; '_core_custom_webservice_get_response',
          'access callback' =&gt; '_core_custom_webservice_access',
          'access arguments' =&gt; array('view'),
          'access arguments append' =&gt; TRUE,
          'args' =&gt; array(
            array(
              'name' =&gt; 'parameters',
              'type' =&gt; 'string',
              'description' =&gt; 'The parameters that define requested data',
              'source' =&gt; array('path' =&gt; '0'), // first argument in the url 
              'optional' =&gt; FALSE,
            ),
          ),
        ),
      ),
    ),
  );
  return $resources;
}

/* * *************************************************************************************************
 * Access callback 
 * For now only view/retrieve is implemented and if the user is logged in, he gets access
 */

function _core_custom_webservice_access($op) {
  global $user;
  $access = TRUE;

  switch ($op) {
    case 'view':
      if ($user-&gt;uid) {
        $access = TRUE;
      }
      break;
  }

  return $access;
}

function _core_custom_webservice_get_response($arg) {
  $response = 'something';
  return 'print '.$response;
}


try again in your service path and success with 
http://path.come/?q=webservice_server_rest/webservice_resources/string.json