Hi. I’ve forked the JavaScript SDK and made it work with Node.js and NW.js (or compatible).
If you want to check it out, use npm install twitch-sdk --save
to install it into your Node package. Don’t forget to read the readme, though, as there are some slight differences to the original SDK.
Feel free to have a look at the source in its GitHub repo, report any bugs you find or fork it and contribute to the code. I have not yet tested it very thoroughly yet so it’s very likely there are some oversights.