My boss was asking what kind of programming interfaces we have into GW

We have a message broker on a server that receives information from another
program. If we have GW Messenger running on the server running the message
broker, is there some way programmatically that we can then have an instant
message generated to the user who sent the message to the message broker if
we have that information available.

I'm not sure if I am making sense. Any ideas would be appreciated.