SecureAid Fundraising – Blockchain Module

A secure, transparent fundraising system for disaster relief built on Ethereum. It enables on-chain donations, live totals, donor visibility, and owner-only withdrawals to verified NGO/Govt wallets.

Features

• Secure on-chain ETH donations via Solidity smart contracts
• Immutable ledger, donor address list, real-time total funds
• MetaMask wallet connection for donors and admins
• Owner-only withdraw to a verified beneficiary
• REST backend for campaign logs and analytics (MongoDB)
• Admin UI for monitoring and management

Tech Stack

• Blockchain: Ethereum (Sepolia or local Hardhat)
• Smart Contracts: Solidity, OpenZeppelin Ownable + ReentrancyGuard
• Web3: ethers v6
• Frontend: Next.js App Router + Tailwind + shadcn (recommended), or React CRA (client/)
• Backend: Node.js + Express + MongoDB (Mongoose)
• Tooling: Hardhat

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1) Prerequisites

• Node.js 18+ and VS Code
• MetaMask browser extension
• MongoDB running locally (or a MongoDB URI)
• Sepolia test ETH if deploying to testnet (get from a faucet)

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2) Smart Contracts (Hardhat)

There are two Hardhat setups:

• Root Hardhat (contracts/ + hardhat.config.js)
• Standalone sample under blockchain/ (optional). Use only one.

Recommended: use the root Hardhat.

1. Copy environment file

   • cp .env.example .env
   • Fill:
     • SEPOLIA_RPC_URL=your Sepolia RPC (Infura/Alchemy, etc.)
     • PRIVATE_KEY=private key of your wallet with test ETH

2. Install deps at project root

   • npm install

3. Compile contracts

   • npx hardhat compile

4. Run a local node (optional)

   • npx hardhat node

5. Deploy

   • For local: npx hardhat run scripts/deploy.js --network localhost
   • For Sepolia: npx hardhat run scripts/deploy.js --network sepolia

6. Note the deployed contract address and update:

   • Next.js UI: create .env.local with:
     • NEXT_PUBLIC_CONTRACT_ADDRESS=0xYourDeployedAddress
   • Server: server/.env (copy server/.env.example) with:
     • CONTRACT_ADDRESS=0xYourDeployedAddress

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3) Backend (Express + MongoDB)

1. Create server/.env from server/.env.example and set:

   • MONGODB_URI=mongodb://localhost:27017/secureaid_fundraising (or your URI)
   • PORT=5000
   • FRONTEND_URL=http://localhost:3000
   • RPC_URL=http://localhost:8545 (or your Sepolia RPC)
   • CONTRACT_ADDRESS=0xYourDeployedAddress

2. Install server deps and start:

   • cd server
   • npm install
   • npm run dev
   • Health check: http://localhost:5000/health

3. Optional seed/migrate scripts (from project root):

   • node scripts/setup-database.js
   • node scripts/seed-sample-data.js

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4) Frontend Options

You have two UIs. Pick one.

A) Next.js App (recommended; lives at app/*)

• At project root:
  • Create .env.local with:
    • NEXT_PUBLIC_CONTRACT_ADDRESS=0xYourDeployedAddress
  • npm install (if not already)
  • npm run dev
  • Open http://localhost:3000
• Features present:
  • Connect Wallet, Donate ETH, Live Totals, Donor List
  • Admin Withdraw (auto-hides if not owner)

B) React CRA client (legacy) in client/

• cd client
• npm install
• npm run dev (or npm start)
• Open http://localhost:3000
• Proxy to http://localhost:5000 is set in client/package.json

Note: use only one frontend at a time on port 3000 to avoid conflicts.

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5) Testing With Local Network (Optional)

• Terminal 1: npx hardhat node
• Terminal 2: npx hardhat run scripts/deploy.js --network localhost
• Import an account into MetaMask using a private key printed by the Hardhat node
• Set NEXT_PUBLIC_CONTRACT_ADDRESS to the local deployed address
• Start the UI and donate small test amounts

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6) Admin Operations

• Admin = contract owner (deployer)
• Owner-only withdraw to a specified address from the Admin panel
• For production: verify the contract on Etherscan and use a hardware wallet for owner actions

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Troubleshooting

• MetaMask not detected: install the extension and refresh
• Missing NEXT_PUBLIC_CONTRACT_ADDRESS: set it in .env.local for Next.js
• Insufficient funds: acquire Sepolia ETH from a faucet when testing on testnet
• MongoDB connection errors: ensure MongoDB is running and MONGODB_URI is correct
• CORS errors: confirm FRONTEND_URL in server/.env matches your UI origin

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Scripts (root package.json)

• npm run dev # concurrently starts server and client CRA (if you choose CRA)
• npx hardhat compile # compile contracts
• npx hardhat node # start local chain
• npx hardhat run scripts/deploy.js --network sepolia # deploy to Sepolia

Use one frontend path (Next.js or client/) for clarity.