Maintaining an API documentation can be very time consuming. In the best case, you'll update the doc before each update, according to the new specifications, but in the real world, you have a deadline, and your colleagues are stuck waiting for your new feature to be implemented. In this case, you might forget to update the documentation. The solution is to use a tool that will dynamically generate this documentation.
Using Swagger UI
, you can document your grape API very easily.