Today, Google launching the first version of the Google+ APIs.
This API release is public data only — it lets you read information that people have shared publicly on Google+.
Note: The Google+ API currently provides read-only access to public data. All API calls require either an OAuth 2.0 token or an API key.
I wait for this API 2 month and it’s only read only service :(.
We’ll have to wait longer for full Google + API.