Dredd is a command-line tool for testing API documentation written in API Blueprint format against its backend implementation.

From the github page of dredd:

Dredd is a command-line tool for testing API documentation written in API Blueprint format against its backend implementation. With Dredd you can easily plug your API documentation into the Continous Integration system like Travis CI or Jenkins and have API documentation up-to-date, all the time. Dredd uses the Gavel for judging if a particular API response is valid or if is not. If you are curious about how decisions are made, please refer to Gavel's behavior specification.