I wanted to let the other home automation tinkerers here know that I've released an npm package (rachio) that works with Node.js v6.0.0 or greater.
It's basically a client wrapper for the public api, but it does have some added functionality that I've found useful in developing my own Rachio applications.
Still in the early stages here, but I'd love to get some feedback from other users / developers. Feel free to contribute code via pull requests, or feature requests via Github Issues.
Hope other folks find this project useful!