What is an API and how can I use it? First of all, an Application Programming Interface (API) is a set of clearly defined methods of communication between various software components. How can you, as a trucking company, use an API in connection with your trucking software? We provide a very simple to use web rating API that gives your customers the ability to retrieve rates automatically over the web. If you haven’t yet been asked by your customers to provide this service, I guarantee you soon will be!