A bidirectional metadirectory agent a data source converter layer; a filters and rules layer for blocking disallowed changes; a mapping layer for translating attributes in change commands from a local set of attribute names to a set of metadirectory attribute names, and vice versa, and for converting change commands between said agent-internal common format and a directory change protocol; an extensible user customization layer for implementing custom metadirectory agent functions; and a metadirectory interface for sending and receiving said change commands in said directory change protocol.