LASTLINE is a transport-agnostic emergency relay system for crisis communication when normal platforms fail.
It is not a chat clone. It is a command-style coordination dashboard that lets users compose urgent messages, attempt primary routing, automatically fail over into degraded mode, generate QR relay packets, verify packet integrity, and track delivery through a live mesh-style topology.
- Composes urgent dispatch packets with priority levels
- Attempts primary delivery first
- Automatically degrades to fallback relay when a route fails
- Generates QR packets for offline / physical handoff
- Verifies packet integrity with SHA-256 checksums
- Shows live protocol logs and route transitions
- Displays a triage queue, archive, and node health view
- Supports Command Center and Field Unit modes
- Persists packets locally so refreshes do not erase state
When standard communication paths fail, people still need a reliable way to send urgent messages, coordinate, and confirm delivery. LASTLINE models that problem as a real transport relay system instead of a normal messaging app.
- Neo-brutalist white-canvas dashboard UI
- Live route topology and packet state transitions
- Crisis composer with macros and priorities
- Degraded mode failover flow
- QR relay and packet ingest
- Tamper detection through signature mismatch
- Live console / event timeline
- Packet archive and triage queue
- Local persistence for demo-safe offline behavior
- React + TypeScript + Vite
- Tailwind CSS
- Framer Motion
- Native Web Crypto API
- QR generation / scanning
- Browser local persistence
- Open the dashboard
- Compose an emergency packet
- Send it through the relay system
- Watch the route fail over into degraded mode
- Generate and verify a QR packet
- Show the archive, triage queue, and integrity check
- Switch between Command Center and Field Unit views
The architecture can later support optional physical relay nodes like ESP32 / ESP-NOW, but the core product is fully functional in the browser.
Built for Build.IT ’26 / First Contact hackathon submission. Developed by Atharv Singh Negi.