I have the problem with Google Adsense API. I used Services Account to authen, and this is my code:
require_once dirname(__FILE__) . \'/google-api-php-client/Goo
Service accounts are not available in the AdSense Management API.
If you want to use the API without user intervention, you can use the "Web application" or "Installed application" scenarios. Once the user grants access to your app, you can start requesting access tokens.
Check out the PHP samples: https://code.google.com/p/google-api-php-client/source/browse/#svn%2Ftrunk%2Fexamples%2Fadsense