This document follows the document produced by the GridRPC-WG on GridRPC Model and API for End-User applications. This new document aims to complete the GridRPC API with Data Management mechanisms and API. This document is not intended to provide features and capabilities for building data management middle- ware. Its goal is to complete the GridRPC set of functions and definitions to allow users to manipulate their data. The motivation for this document is to provide explicit functions to manipulate the exchange of data between users, components of a GridRPC platform and storage resources since (1) the size of the data used in Grid applications may be large and useless data transfers must be avoided; (2) data are not always stored on the client side but may be made available either on a storage resource or within the GridRPC platform. All functions in the API have been thought to be called by each part in a GridRPC platform (client, agent and server) if needed.