eFrogs Attestation

🐸 Overview

This project enables eFrogs NFT holders on Linea to create ownership attestations via the Verax Attestation Registry. Initially developed during the Linea/eFrogs hackathon in April 2024 (2nd place), it is now available on Linea Mainnet.

🌐 Demo: efrogs.alainnicolas.fr

📁 Project Structure

This is a pnpm monorepo with two packages:

packages/
├── contracts/   # Solidity smart contracts (Hardhat)
└── frontend/    # React SPA (Vite + wagmi + Reown AppKit)

🏗️ How It Works

┌─────────────┐     ┌──────────────┐     ┌─────────────────┐
│   Frontend  │────▶│ EFrogsPortal │────▶│ Verax Registry  │
│  (React)    │     │  (Solidity)  │     │  (Attestations) │
└─────────────┘     └──────────────┘     └─────────────────┘
       │                   │
       ▼                   ▼
┌─────────────┐     ┌──────────────┐
│ User Wallet │     │ eFrogs NFT   │
│  (wagmi)    │     │  Contract    │
└─────────────┘     └──────────────┘

1. User connects their wallet via Reown AppKit (WalletConnect)
2. Frontend queries the eFrogs NFT contract for user's balance
3. If balance > 0, user can create an attestation
4. User pays 0.0001 ETH fee to the Portal
5. Portal verifies ownership on-chain and creates a Verax attestation
6. Attestation is stored with schema: (address tokenContract, uint256 balance)
7. Attestation expires after 30 days

📋 Prerequisites

• Node.js >= 22.21.1 (see .nvmrc)
• pnpm >= 10

# Install the correct Node.js version
nvm use

# Install pnpm if not already installed
corepack enable
corepack prepare pnpm@latest --activate

🛠 Technologies

• Frontend: React 19 + TypeScript + Vite 7
• Smart Contracts: Solidity 0.8.21 + Hardhat 3
• Wallet Connection: wagmi v3 + viem v2 + Reown AppKit
• Attestations: Verax Attestation Registry
• Network: Linea (mainnet & Sepolia testnet)
• Deployment: Netlify

🚀 Installation

# Install dependencies
pnpm install

# Copy environment variables
cp packages/frontend/.env.example packages/frontend/.env
# Then edit .env with your API keys

# Start development server
pnpm dev

🔧 Environment Variables

Frontend (packages/frontend/.env)

Variable	Description	Required
VITE_WALLETCONNECT_PROJECT_ID	WalletConnect Cloud Project ID	Yes
VITE_INFURA_API_KEY	Infura API Key for RPC	Yes
VITE_GRAPH_API_KEY	The Graph API Key	Yes

Contracts (packages/contracts/.env)

Variable	Description	Required
INFURA_KEY	Infura API Key	Yes
PRIVATE_KEY	Deployer private key (with 0x)	Yes
ETHERSCAN_API_KEY	Lineascan API Key for verification	Yes
ROUTER_ADDRESS	Verax Router address	For deployment
EFROGS_ADDRESS	eFrogs NFT contract address	For deployment

📜 Available Scripts

Root (monorepo)

pnpm dev              # Start frontend dev server
pnpm lint             # Run ESLint + Solhint on all packages
pnpm lint:fix         # Auto-fix linting issues
pnpm format           # Check Prettier formatting
pnpm format:fix       # Auto-fix formatting
pnpm typecheck        # TypeScript type checking
pnpm test             # Run Hardhat tests

Contracts (packages/contracts)

pnpm compile                               # Compile Solidity contracts
pnpm deploy:portal --network linea         # Deploy portal to mainnet
pnpm deploy:portal --network linea-sepolia # Deploy portal to testnet
pnpm deploy:nft --network linea-sepolia    # Deploy test NFT (testnet only)

Frontend (packages/frontend)

pnpm dev              # Start dev server with HMR
pnpm build            # Build for production
pnpm preview          # Preview production build

📊 Deployed Contracts

eFrogs NFT

Network	Address
Linea Mainnet	0x194395587d7b169e63eaf251e86b1892fa8f1960
Linea Sepolia	0x35c134262605bc69B3383EA132A077d09d8df061

EFrogsPortal (Verax)

Network	Address
Linea Mainnet	0x5f47bCeB43B8114cf85d3Ac50e9850164dE2984e
Linea Sepolia	0x407e280281B812Adef69A91230659C9D738D82Cb

Attestation Schema

Network	Schema ID
Linea Mainnet	0x5dc8bc...d2f5
Linea Sepolia	0x5dc8bc...d2f5

Schema structure: (address tokenContract, uint256 balance)

🔀 Fork & Adapt

To adapt this project for your own NFT collection:

1. Smart Contract

Modify packages/contracts/src/EFrogsPortal.sol:

• Update constructor to accept your NFT contract address
• Adjust the fee if needed (default: 0.0001 ETH)
• Optionally create a new Verax schema for your data structure

2. Deploy & Register

# Set environment variables
export ROUTER_ADDRESS=0x... # Verax Router (see docs.ver.ax)
export EFROGS_ADDRESS=0x... # Your NFT contract

# Deploy
pnpm --filter contracts deploy:portal --network linea-sepolia

The deploy script automatically:

• Deploys the portal contract
• Verifies on Lineascan
• Registers the portal with Verax

3. Frontend Constants

Update packages/frontend/src/utils/constants.ts:

• EFROGS_CONTRACT / TESTNET_EFROGS_CONTRACT: Your NFT addresses
• PORTAL_ADDRESS / TESTNET_PORTAL_ADDRESS: Your portal addresses
• SCHEMA_ID: Your schema ID (if created new)
• Subgraph URLs if using custom indexing

4. Branding

• Replace assets in packages/frontend/public/
• Update styles in packages/frontend/src/App.css

🔗 Useful Links

• eFrogs Website
• Verax Documentation
• Linea Network
• Reown AppKit
• wagmi Documentation

📄 License

MIT License - see LICENSE for details.

🤝 Contribution

Contributions are welcome! Feel free to open an issue or a pull request.

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request