[hassox]

If you're generating the page from your rails server then the cookie that is set for sessions would be already available and you can make calls without worrying too much about authentication. If you want to use tokens or OAuth strategies there's a bit more to it but you should be able to find lots of information on it with a bit of googling. Here's an article that seems to cover the basics. https://technpol.wordpress.com/2013/09/23/angularjs-and-devi...

I'd usually google for a collection of the tools I'm looking at. To find that article I searched for "spa authentication with rails and devise"

Good luck with your side project :D