Yes.
> Question 2: In the documentation for the Channel API it says: "The
> JavaScript client opens a socket using the token provided by the server. It
> uses the socket to listen for updates on the channel." However
> communication from the client to the server seems to be in the form of a
> POST.
> Are Channel API sockets truly uni-directional server-to-client? Or is there
> a way for the client to communicate back via web socket?
No; server-to-client is implemented using long-polling. The
client-to-server uses POST requests back to the server.
Robert