A method of synchronizing data between multiple endpoints each storing a copy of the data in accordance with different underlying schemas. An application model that provides a logical representation of an underlying schema is extended with a synchronization model that provides a logical representation of changes made to the data. The synchronization model comprises functions that provide synchronization information on the changes in a common format. Using such synchronization information, changes in a copy of the data stored in a first underlying schema on a first endpoints are applied to another copy of the data stored in a second underlying schema on a second endpoint in synchronization relationship with the first endpoint.