A stalker portal is a link between your MAG device and the IPTV feeds which supplies all the necessary information to get the stream from the IPTV providers to your TV. What is IPTV?
Stalker portal on KODI
Stalker Client is an emulator PVR Client Addon for Kodi to connect to Stalker Middleware to emulate an STB feeling and look for Internet-based television (IPTV) which is typically obtained through IPTV setup boxes such as MAG254/255.