Howto act as server and bidrectionally communicate with client

[ssshake]

After referring to the examples and the docs I don't seem to follow how I can act as a server, and receive input from a client and respond in kind.

The docs about data and commands are from the perspective of this library as a client, not a server. I substituted the client object with my server object and neither subscription to data or commands seems to amount to anything.

I think I'm just missing something minor here but I don't know what.