fortnox-api

https://github.com/accodeing/fortnox

Fortnox's REST API wraps every payload in a type key, spells its attributes in PascalCase, and treats an empty string as "leave this field alone" when you meant to clear it. This gem turns it into ordinary immutable Ruby objects with typed, constrained attributes, so a value Fortnox would reject raises before it costs an API call, and authorization, pagination and JSON mapping are handled for you.