I have been trying to use Racket for my research (when I can that is) and recently I had to use Yahoo!'s BOSS API for some work. I couldn't find an oauth library for Racket so I had to roll one out myself. The lib currently supports HMAC-SHA1 signing and can only handle consumer requests (since that is all I had to accomplish). If you need our library, you can get it from the LemurProject github repo.