Google PHP Client API: Insufficient Permission

Question

I have PHP code that use Google PHP Client API to use Drive service.

Answer 1

The apps#list method requires authorization with the scope https://www.googleapis.com/auth/drive.apps.readonly. Just add it to the array of scopes:

$client->setAssertionCredentials(new Google_Auth_AssertionCredentials(
  SERVICE_ACCOUNT_NAME,
  array('https://www.googleapis.com/auth/drive', 'https://www.googleapis.com/auth/drive.apps.readonly'),
  $key)
);

Answer 2

You must even disable Google drive api for your project in Developer Console under Apis & auth