Application programming interface for implementing directory service access using directory service markup language

A set of DSML application programming interface (DSML API) functions is provided to facilitate the implementation of DSML-based directory service access. The DSML API includes a DSML document API class for building or accessing a DSML payload, and a DSML connection API class that handles connection and transport to a DSML server. To access a directory service, the client calls functions of the DSML document API class to generate a DSML request payload, and calls functions of the DSML connection API to transport a packet with the DSML request payload according to a pre-selected connection protocol, such as SOAP, to the DSML server for forwarding to the directory service.