What is an API? Brian Royce July 12, 2016 21:07 Follow Application program interface (API) is a set of routines, protocols, and tools for building software applications. An API specifies how software components should interact. Related articles What is SSL? Inventory Stock Options Setting up Sitebiz email on your devices Authorize.net Integration Edit & Add Sliding Banners Comments 0 comments Please sign in to leave a comment.