Finding out my User Agent on Node Weblit

When using browser context in Node-Webkit, is there any way to find out what is the exact User Agent used for external requests, from within Node-Webkit?

Example: if Node-Webkit loads an image that's in an HTML from some remote, I would like to know what's the User Agent this remote will see.

Using a sniffer (Fiddler/Wireshark) is trivial, but I'm looking for a method to obtain this information directly.

Thank you.