Four components, one chain of custody. Edge — Officer Mobile: Expo / React Native. Camera, NFC, geolocation, offline cache, encrypted session. Command — Admin Portal: React + Vite supervisor console. Live movements, watchlist hits, geofence map editor. Core — API Server: Node + Express. AES-GCM transport, MRZ pipeline, ArcFace inference, geofence logic. Records — BMIS · Postgres: traveller history, descriptors, audit trail and border locations.