An application programming interface (API) implementation that can interface between an application and a programming library. The implementation includes a Function Router Wrapper that receives a formatted string from the application. The formatted string includes a function name element filled with a function name, an input element filled with function input parameters, and an unfilled output element. The Function Router Wrapper converts the formatted string and passes it to a Function Router, which parses the converted formatted string to access the function name and the function input parameters. The Function Router calls a library function based on the accessed information. When the called library function is completed, the Function Router collects generated function outputs and embeds them into the formatted string output element. The Function Router passes the formatted string back up to the Function Router Wrapper, which converts the formatted string and passes it back up to the application.