How do I get started with Amazon AWIS (AlexaWebInfoService) in node.js?

I want to use Amazon AWIS in my code and I have absolutely no idea where to get started with this signing. I know there is SDK for node.js but it seems that AWIS is not supported yet.

Can somebody give me an example how to create a signature for a request? This article describes the signing process, but I have absolutely no idea how to to this in node.