A method includes receiving a representation of a service, the service including handling of a request for a context-dependent data set derived from one or more collections of data elements. The representation includes a specification of a first data field, a specification of an input data structure including two or more data fields and the first data field, the two or more data fields defining a context for the first data set, a specification of an output data structure, instances of the output data structure including the context-dependent data set, and a name of a service provider. The method stores the representation of the service in a repository, receives a request for the service by a software entity, the request including an instance of the input data structure, checks the request against the representation of the service, sends the request to the service provider, receives one or more instances of the output data structure from the service provider, and sends the one or more instances of the output data structure to the software entity.