try
{
   $client = \XF::app()->http()->client();
   $response = $client->get("https://api.developertracker.com/anthem/posts");
}
catch (\GuzzleHttp\Exception\RequestException $e)
{
   if (null !== $e->getResponse())
   {
      $error = 'Tracker Error ' . $e->getResponse()->getStatusCode() . ': ' . $e->getResponse()->getReasonPhrase();
   }
   else
   {
      $error = $e->getMessage();
   }
   return $this->error($error);
}
$yourInfo = \GuzzleHttp\json_decode($response->getBody(), true);
print_r($yourInfo);
die();