I cannot figure out how I can call into a SignalR hub from a WebAPI ApiController. I have put together a sample you can download here that simplifies the problem and demons
You are calling different methods on the client:
API controller
hubContext.Clients.Group("TestGroup").send("TestGroup", "Called from Controller");
Hub
Clients.Group(room).newMessage(msg);
The method you want to call is newMessage not send
chat.client.newMessage = onNewMessage;