SEP events can pose a significant radiation hazard for human and robotic space exploration activities. The Relativistic Electron Alert System [1] utilizes the fact that near relativistic electrons travel faster than energetic ions (30 MeV protons have 25% of the speed of light) and are always present in hazardous SEP events. Their early arrival can be used to warn against high proton fluxes near Earth. Originally REleASE uses real time data from the SOHO EPHIN and was later expanded to use measurements from the ACE EPAM called HESPERIA/REleASE [2]. We now applied the method to the HET and the SEPT on board of STEREO-A in order to develop a STEREO/REleASE system. This gives us the possibility to test and validate the method with different kind of instruments and energy ranges, which will help to adapt the system to upcoming missions (e.g. NASA’s IMAP). The recent fly-by of STEREO-A past the Earth in 2023 allowed for a direct comparison between the predictions of STEREO/REleASE and the original REleASE.