Fifth generation (5G) mobile networks possess capabilities to address the strong requirements of mission critical communications for low latency, very high reliability and availability. Further improvement of network performance can be achieved by applying Multi-access Edge Computing (MEC) paradigm for distributing the computing and storage capabilities at the network edge. In this paper, we propose a new mobile edge service which provides notifications about session related events to applications and enables applications to determine the further session handling. The service, which follows Representational State Transfer style, is described by its resources and supported methods. The service performance is evaluated by emulation.