What is the API Codec? If you are working with TCP/IP or Wireless communications, you might want to consider using the API Codec to handle all communication functions. The API Codec will “wrap” standard commands with a Header, Byte Counter, and a Checksum, which eliminates the need for timeout command processing (the standard method of communications which stalls processing of commands). he API Codec is a faster, more reliable method of communicating to NCD devices, particularly when working with network- or wireless-based devices. The API Codec makes communications more resilient to errors and eliminates timeout requirements of standard communication methods.