A real-time notification system is often useful, if not necessary, to handle unexpected events in order to make humans or their automated counterparts aware of what's going on while things happen. An unhandled exception could well be one of those scenarios where such a system could become interesting. In this recipe, we'll see how we can set up a sample application so that it can intercept unhandled exceptions in a single central place and post them to a monitoring system that will then use SignalR to broadcast the details about the errors it receives to its users.

We will not need many features from SignalR; actually, the only feature that we'll really need is the capability to invoke a client-side callback from outside any hub's method, thanks to the hub context.