Hi,To access an AdWords account's data via the API, you need two things: a developer token (associated with a manager account) and valid OAuth credentials (associated with the target AdWords account or the manager account of the target AdWords account).
Access levels related to a developer token define the limits on your account (such as test vs production accounts and the number of operations that you can perform with your token). When a user creates a new developer token, the default access level is
Test Access, which means that the user would be able access
test accounts only. When a user submits an application for
Basic Access (using
this form), and the application is approved, the user is able to access production AdWords accounts with a limit of 10,000 operations per day (complete rate sheet can be found
here).
Standard Access accounts on the other hand, have no such limit.
OAuth credentials, however, can be used to control data access to a user on a particular account. To grant a user read-only access, you can add a new user to your AdWords account using
this guide with read-only permissions. When the user uses this email address to create OAuth credentials for the API, they will have read-only access to the API by default.
Hope this helps. If you have additional questions, please feel free to revert.
Regards,
Vishal Vinayak, AdWords API Team