You might have seen the announcement last week about OAuth 2.0 coming to Google APIs. It’s a great step forward that will make it much easier for web, mobile, and desktop applications to securely access user data. What you might not have heard is that OAuth 2.0 already works with many of the Google Apps APIs like contacts, calendar and docs.
Because the spec is still under development, OAuth 2.0 support is considered experimental until the spec is stabilized. In the mean time, if you’re interested in learning more about it you can give it a try with some of the APIs you’re already familiar with.
One small tip -- if you know the user is a Google Apps account and you already know the user’s domain, try adding the query parameter “hd” with the domain name as the value when requesting authorization. The hint helps provide a better login experience for Google Apps users. For users on domains that haven’t yet upgraded to the new account system it’s required for now, but we’re working on improving the user and developer experience to make it even easier.