Developing applications for distributed adaptive computing systems (ACS) requires developers to have knowledge of both parallel computing and configurable computing. Furthermore, portability and scalability are required for developers to use innovative ACS research directly in deployed systems. This thesis presents an Application Programming Interface (API) implementation developed in a scalable parallel ACS system. The API gives the developer the ability to easily control both single board and multi-board systems in a network cluster environment. The API implementation is highly portable and scalable, allowing ACS researchers to easily move from a research system to a deployed system. The thesis details the design and implementation of the API, as well as analyzes its performance.