Rails app, gmail gem, xoauth: How to grant access to a specific application?

I have a Rails application in which I would like to use the gmail gem to connect to a Google Apps account via XOauth and retrieve emails. I followed the gmail_xoauth instructions using the xoauth.py tool to generate tokens. This gives "anonymous" access to my Google Account. I am able connect via my Rails console just fine using these credentials.

I see that the gmail_xoauth gem has options for :consumer_key and :consumer_secret. I used "anonymous" for each of these. But, if my Rails application is going to be running at, say, http://someapp.example.com, how do I grant access to this a开发者_JS百科pplication specifically and not use "anonymous"?

Thanks.