PigeonMesh: Flying Messages Beyond Blackouts

When floods, natural disasters, or total internet shutdowns strike, mobile towers collapse and central networks go silent. Victims, emergency rescuers, and families are left completely stranded. Existing solutions fail in real-world crisis situations for critical reasons: 1. Standard messaging apps like WhatsApp depend on cellular towers, central servers, SIM cards, and internet downloads that are unavailable at ground zero. 2. Specialized mesh hardware like LoRa or Meshtastic requires custom radios that regular citizens do not own or carry. 3. Satellite communications are far too expensive and rare for ordinary victims stranded on rooftops. 4. Running phone hotspot 24/7 or running pc server is not a feasible solution. 5. Emergency SMS broadcasts only work one-way, preventing victims from sending SOS alerts or missing person details back to rescuers. During crises, trapped citizens need immediate local communication, emergency SOS routing, and missing person tracking using the devices they already own, without depending on external infrastructure.

PigeonMesh is a lightweight software package that turns ordinary, low-cost OpenWrt Wi-Fi routers into an autonomous local communication network. It works completely offline over local Wi-Fi without needing internet connection, app store installation, account sign-up, or cellular data. People in disaster zones simply connect to the router Wi-Fi and open http://pigeon.mesh/ in any mobile browser. The web app provides real-time local chat across public, relief, and medical channels, instant one-touch SOS alerts, missing person reports with compressed photos, and offline OpenStreetMap navigation cached inside IndexedDB. Unlike traditional mesh systems that break when nodes lose direct radio contact, PigeonMesh uses a store-and-forward mechanism inspired by carrier pigeons. When two mesh networks are physically separated by floodwaters or distance, any person walking between isolated nodes automatically carries cryptographically signed records inside their phone browser storage. When they arrive in range of another node, the networks merge and reconcile missing records automatically without internet. Additionally, PigeonMesh integrates with cheap hardware sensors like an ESP32 float switch. When rising water trips a switch at an embankment, an SOS alert is raised across every node without human intervention. If any single router gets an internet uplink, an optional cloud bridge syncs the local mesh with remote relief coordinators.

Router Software: OpenWrt, Lua 5.1, Shell scripting, Nixio socket library, dnsmasq, nftables/iptables. Frontend Web App: HTML5, CSS3, Vanilla JavaScript, IndexedDB (for offline OpenStreetMap tile caching). Cryptography: Ed25519 for record signing, ChaCha20/Poly1305 for end-to-end encryption. Cloud Bridge: Next.js, TypeScript, Vercel, TailwindCSS. Hardware / IoT: ESP32 DevKit v1, C++ (Arduino framework), marine float switch sensor, active buzzer.

GLM, Claude and Gemini were used for pair programming, code debugging, refactoring, and documentation assistance.