We don't have any documentation at this time. We will be prioritizing API documentation and usage documentation after we've launched our new site. See the below on upgrading old API usage to new API usage as well as trigger firing information.
www.joomlapolis.com/forum/255-developer-members-support/230774-using-new-cb-activity-with-api#268745
The best way to integrate, if you don't need custom display/access parsing, is to just fire a CB trigger and let CB Auto Actions act on it (see System Actions for examples). If you need custom display/access parsing see GJ RC1 and its integrations as they all extend the activity query with custom access checks and have display parsing for the GJ activity entries.