🚨 ReliefMesh: Decentralized Disaster Response Platform

"Unstoppable Aid for an Unpredictable World"

🏆 Submission for Hackathon 2026

TRACK 3: Digital Resilience

💡 Inspiration

In the wake of natural disasters, communication infrastructure often fails. Centralized servers go down, and traditional banking systems become inaccessible. ReliefMesh was born to answer one critical question: "How can we coordinate rescue and funding when the internet is broken?"

🚀 What is ReliefMesh?

ReliefMesh is an offline-first, peer-to-peer (P2P) disaster management platform. It allows victims to broadcast SOS signals that hop between devices without needing a central server. Simultaneously, it integrates Ethereum Smart Contracts to enable direct, transparent, and fee-free financial aid from donors to victims.

✨ Key Features

• 📡 Unstoppable P2P Mesh: Powered by Gun.js, allowing devices to sync emergency data directly.
• 💸 Direct Crypto Aid: Donations via MetaMask on Sepolia Testnet (Zero fees, Instant transfer).
• 🗺️ Live Command Center: Real-time map visualization of SOS clusters.
• 📱 Cross-Device Sync: Works seamlessly between Mobile and Desktop via Relay.

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🛠️ Tech Stack

• Frontend: React 18, TypeScript, Vite, Tailwind CSS
• P2P Database: Gun.js
• Blockchain: Ethers.js, Sepolia Testnet
• Maps: Leaflet, OpenStreetMap
• Tunneling: Ngrok (For public demo)

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🚀 Getting Started (Run the Demo)

To see the full capabilities (P2P Sync & Cross-device), please follow these steps strictly:

Prerequisites

• Node.js (v18+)
• MetaMask Extension (Browser or Mobile)
• Ngrok Account (Free tier is fine)

Step 1: Clone & Install

git clone [https://github.com/your-username/relief-mesh.git](https://github.com/your-username/relief-mesh.git)
cd relief-mesh
npm install

Step 2: Start the Relay Server (Terminal 1)

This acts as a "superpeer" to help sync data between devices during the demo.

node relay.cjs
# Output: ✅ Local Relay started on port 8765

Step 3: Expose Relay to Internet (Terminal 2)

Required for mobile devices to connect to your local computer.

npx ngrok http 8765

⚠️ Important: Copy the https://....ngrok-free.app URL from this terminal and update src/hooks/useRelief.ts with this new link.

Step 4: Run the Frontend (Terminal 3)

npm run dev

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🧪 Demo Guide: How to Test on PC & Mobile

Since this system works cross-device, it is crucial to distinguish between the "Code Link" (Backend) and the "Browser Link" (Frontend).

🖥️ 1. Testing on Computer (PC / Notebook)

For the host machine, you can simply use Localhost.

1. Open Browser: http://localhost:5173
2. Important: The browser will ask for Location Access. Click Allow to see your pin on the map.

📱 2. Testing on Mobile

Mobile devices cannot access localhost directly. You need to create a separate tunnel for the frontend.

1. Open a New Terminal (Terminal 4).

2. Run the command to expose the frontend:Bash

   npx ngrok http 5173

3. Copy the Forwarding URL (e.g., https://xxxx-xxxx.ngrok-free.app).

4. Open this link on your Mobile.

5. Important: Open the link inside the MetaMask Browser app to test the Donation feature.

🚨 Summary: Which Link is Which?

Port / Command	Usage
8765 (ngrok http 8765)	❌ DO NOT OPEN IN BROWSER. Use this URL only inside useRelief.ts code (Backend P2P Tunnel).
5173 (ngrok http 5173)	✅ OPEN THIS LINK. Use this to view the app UI on mobile or share with judges.

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🧪 How to Test (Scenarios)

1. P2P Sync Demo

• Open the app on Desktop and Mobile.
• On Mobile, click the SOS Button and submit a request.
• Watch the Desktop Map update instantly without refreshing!

2. Donation Demo (Sepolia)

• Click on any SOS Pin on the map.
• Click "Connect Wallet" (Supports MetaMask).
• The app will automatically switch you to Sepolia Testnet.
• Click "Donate 0.001 ETH" to simulate a transaction.