current internet infrastructure is still configured and managed manually or adopting a limited level of automation. The Future Internet aims to provide the network resources as a service to ease the process of automatic designing, controlling and supervising the telecommunication infrastructure. A key enabler of the Future Internet is the virtualization of the available resources and of the related functionalities. The widespread of cloud computing, Software Defined Network (SDN) and Network Function Virtualization (NFV) technologies opened the way for a total control of programmable networks. Many open and commercial implementations have adopted this paradigm, but they expose a fragmented set of dissimilar interfaces that often offer similar or even overlapping functionalities. The result is that uncontrolled, open-loop routines and procedures still require a manual intervention. In this paper, we describe an open interface and its reference implementation, to control programmable networks adopting a novel, closed-loop approach based on end-users feedbacks. The proposed interface has been implemented as a Future Internet Generic Enabler named OFNIC.