title: Facebook v2.8 access token without login
body: <p>I try to fetch events from a facebook page and it works well with a temporary access token (code below). I've searched lots of QA's for an answer about how to get a permanent access token or something similar.</p>
  
  <p><strong>There is no user-login on my website, it is just about fetching the JSON - no interaction.</strong></p>
  
  <p>Then I found this</p>
  
  <pre><code>https://graph.facebook.com/oauth/access_token?             
      client_id=APP_ID&amp;
      client_secret=APP_SECRET&amp;
      grant_type=fb_exchange_token&amp;
      fb_exchange_token=EXISTING_ACCESS_TOKEN 
  </code></pre>
  
  <p>to "change" my token into a 60day token but I get an Error:</p>
  
  <p><code>Error validating client secret.</code></p>
  
  <p>And I can assure you, that my client secret is correct.</p>
  
  <p>So what I have is:</p>
  
  <ul>
  <li>Page ID, App ID, App Secret</li>
  </ul>
  
  <p><strong>And what I do is basically this: (works with the temp access token)</strong> </p>
  
  <pre><code>$page_id = "xxx";
  $app_id = "xxx";
  $token = "xxx";
  $object = json_decode(file_get_contents("https://graph.facebook.com/v2.8/".$page_id."/events?fields=id,name&amp;access_token=".$token));
  
  
  &lt;pre&gt;
    &lt;?php print_r($object); ?&gt;
  &lt;/pre&gt;
  </code></pre>
  
  <p>What to do now? Did I miss something? </p>
  
  <p>Thanks a lot</p>