Methods and apparatus, including computer program products, are provided for providing a language for defining a service. In one embodiment, there is provided a method for making a call to the service having a business object. Moreover, the method may include formatting a message based on a language, the language defining an interaction with the business object at the service and an association between the business object and a business object node, the association enabling an instantiation of the business object including the business object node; and calling the service using the formatted message, such that the formatted message instantiates the business object.