API Calculus is a program that solves calculus problems using operating systems within a device that solves calculus problems. In 1989 the PI- Calculus was created by Robin Milner and was very successful throughout the years. The PI Calculus is an extension of the extension of the process algebra CCS, a tool that has algebraic languages that are specific to processing and formulating statements. The PI Calculus provides a formal theory for modeling systems and reasoning about their behaviors. In the PI Calculus there are two specific variables such as name and processes. But it was not until 2002 when Shahram Rahimi decided to create an upgraded version of the PI- Calculus and call it the API Calculus. Milner claimed the detailed characteristics of the API Calculus to be its "Communication