Hello,
The developerToken is a string associated with your MCC, that must be approved, that would grant you access to perform API operations. You can read more information about how to get a developer token at our guide on
signing up.
The userAgent is a custom string that uniquely identifies your platform. This is not something that comes from Google, but something that you can set.
The client_id and client_secret are retrieved through the Google Developer Console.
The refresh_token is obtained using the client_id and client_secret. You can use one of our utilities in
this section of the OAuth 2.0 guide to generate the refresh token.
Let me know if you have any more questions or need more detailed instructions about any of these steps.
Regards,
Mike, AdWords API Team