Current Data as a Service solutions present a lack of flexibility in terms of allowing users to customize the underlying data models by including new concepts or functionalities. Data providers either publish global APIs to make data available, or 'sell' and transfer data to clients so they can do whatever they want with it. Thereby, collaboration and B2B becomes limited and sometimes is not even feasible. Our technology implements the necessary mechanisms for data providers to enable their clients to enrich data models both with additional concepts and with new methods that can be executed and, in turn, published as new services.