Thank you for this; I believe it fills a big hole in the ecosystem. I found myself wanting to implement an API endpoint about six months before your first commit to this project, so I hit Github expecting to find a couple of OAuth-provider Ruby libraries in competition; I'd pick one and do a day or two of work to get it integrated.

Instead, I couldn't find much of anything.

So I delegated the task to someone else who I believe ended up implementing… Basic auth over TLS. ;)