1. A computer readable medium including program code for providing a message-based interface for exchanging information about address snapshots, the medium comprising: program code for receiving via a message-based interface exposing at least one service as defined in a service registry and from a heterogeneous application executing in an environment of computer systems providing message-based services, a first message for requesting to create an address snapshot, including one or more addresses associated with an individual, the first message including a message package hierarchically organized as: an address snapshot create request sync message entity; and an address snapshot package including an address snapshot entity, wherein the address snapshot entity includes at least one web entity, at least one email entity, and at least one name entity; and program code for sending a second message to the heterogeneous application responsive to the first message.