Receive alert with Node.js webToolkit

I am developing a desktop application using Node-Webkit.

Now I need to receive push notifications from somewhere. Here's what's going on: 1) Android app sends a message to my WebApi server 2) My WebApi server receives this message and forwards it to my Node-Webkit desktop app

The desktop application cannot poll the server, so I need a callback that "wakes up" the desktop application to display the message on the screen.

So I need a service that can send push notifications to the Node-Webkit client.

Is there a way to do this?

Thank you so much!