Backend API for Aphasia - Verified Reviews powered by Web3.

• Framework: Node.js + Express + TypeScript
• Database: PostgreSQL (Neon) + Prisma ORM
• Blockchain: Hedera (HCS + Smart Contracts)
• Storage: IPFS (Pinata)
• Auth: Email + JWT
• Optimization: Merkle Tree Batching (99% cost reduction)

• Node.js 18+
• Neon database account
• Hedera testnet account
• Pinata account

# Install dependencies
npm install

# Create .env with your credentials
cat > .env <<'ENV'
# Database
DATABASE_URL="postgresql://username:password@localhost:5432/aphasia_db"

# JWT
JWT_SECRET="your-super-secret-jwt-key-here"

# Hedera
HEDERA_TESTNET_RPC_URL=https://testnet.hashio.io/api
HEDERA_PRIVATE_KEY=0x...
HEDERA_ACCOUNT_ID=0.0.xxxxxx
REVIEW_ATTESTATION_ADDRESS=0x...
CONTRACT_ID=0.0.xxxxxx
BATCH_ATTESTATION_ADDRESS=0x...
BATCH_ATTESTATION_CONTRACT_ID=0.0.xxxxxx
HCS_TOPIC_ID=0.0.xxxxxx

# Review weights
WEIGHT_L1=0.5
WEIGHT_L2=1.0
WEIGHT_L3=2.0

# IPFS (Pinata)
IPFS_URL=https://api.pinata.cloud
IPFS_PROJECT_ID=your-pinata-project-id
IPFS_PROJECT_SECRET=your-pinata-project-secret

# Server
PORT=3000
NODE_ENV=development
CORS_ORIGIN=*
ENV

# Run database migrations
npm run prisma:migrate

# Generate Prisma Client
npm run prisma:generate

# Start the server
npm run dev

• L1 Reviews: Email verification only
• L2 Reviews: Email + Social media verification
• L3 Reviews: L2 + Biometric/Self Protocol verification

• Merkle Tree Batching: Groups multiple reviews into single on-chain transaction
• Cost Reduction: From ~$0.05-0.15 to ~$0.001-0.005 per review
• Automatic Processing: Batches every 100 reviews or 1 hour
• Real-time Verification: Immediate HCS + Batched contract attestation

• Hedera Consensus Service (HCS): Immutable message ordering
• Smart Contracts: Review attestation and verification
• IPFS Storage: Decentralized content storage via Pinata
• Merkle Proofs: Efficient verification of batch attestations

• POST /api/v1/reviews/l1 - Create L1 review
• POST /api/v1/reviews/l2 - Create L2 review
• POST /api/v1/reviews/l3 - Create L3 review (individual)
• POST /api/v1/reviews/l3-batch - Create L3 review (batch optimized)

• GET /api/v1/batch/status - Get batch processing status
• POST /api/v1/batch/force - Force batch attestation

• GET /api/v1/reviews/product/:productId - Get product reviews
• GET /api/v1/reviews/content/:reviewId - Get review content from IPFS
• POST /api/v1/ipfs/upload - Upload content to IPFS

# Check on-chain status and batch attestations
npm run monitor

# Check batch optimization status
curl http://localhost:3000/api/v1/batch/status

• HCS Topic: https://testnet.hashscan.io/topic/{HCS_TOPIC_ID}
• Individual Contract: https://testnet.hashscan.io/contract/{CONTRACT_ID}
• Batch Contract: https://testnet.hashscan.io/contract/{BATCH_ATTESTATION_CONTRACT_ID}