A Shaf project is simply just a Sinatra project. It uses the modular style (see the Sinatra documenation for more info about classic style vs modular style). Shaf provides some conventions (e.g. class/file structure, scaffolding etc), some extensions, and a few helpers. But basically it's just Sinatra. This means that if you are wondering how to implement something in your api, then the Sinatra documentation will most likely have the answers for you. However if it's a Shaf specific thing that isn't obvious how it should be done, then please open an issue in the Shaf github repo.