gistfile1.txt

use OCLC\Auth\WSKey;
use OCLC\Auth\AccessToken;
use OCLC\User;

$key = 'api-key';
$secret = 'api-key-secret';
$services = array('SCIM');

$user = new User('128807', 'principalID', 'principalIDNS');
$options = array('services' => $services);
$wskey = new WSKey($key, $secret, $options);

$accessToken = $wskey->getAccessTokenWithClientCredentials(128807, 128807, $user);
$userid = 'something';

$url = 'https://128807.share.worldcat.org/idaas/scim/v2/Users/'.$userid

   $client = new Client();
   $headers = array();
   $headers['Authorization'] = 'Bearer ' . $accessToken->getValue();
   try {
      $response = $client->request('GET', $url, ['headers' => $headers]);
      echo $response->getBody(TRUE);
   } catch (RequestException $error) {
      echo $error->getResponse()->getStatusCode();
      echo $error->getResponse()->getBody(true);
   }