How can you get a list of groups from a gmail user?

I am building a web app that utilizes groups, facebook groups, email list groups etc. . However, I realized google doesn't offer API access to groups the way facebook does(I was surprised really). I just want read access, and maybe the ability to send an email to a gmail user's group of choice. Any workarounds? 开发者_如何学GoHow can you get a list of groups from a gmail user? How can i post to the said user's group(s)

I mean if there is no API, you're not getting access...