Social Network plugin is not availble for now.
but you still have little patience. next week we will release a beta version (however, very stable )

That is so awesome!
I was using easy-social but they just keep making it bigger and heavier with each update.
I need a light weight community with an activity stream, profile, and the ability to link new cobalt records to the stream.
will this be possible in the next release or soon after?

Hi,
I not have experience with cobalt.

the first version not have API to add activity stream BUT you can add activity by adding a single record in one table.