🏗️ Monad DApp

A cross-chain ETH bridge built using Hardhat, Solidity, Pyth Oracle, and a Relayer Service. This project enables users to transfer ETH between Ethereum Sepolia, Arbitrum Sepolia, and Base Sepolia testnets with the help of an automated relayer.

🚀 Features

• Deposit & Withdraw ETH Across Chains
• Uses Pyth Oracle for price verification
• Automated Relayer Service for processing transactions
• Secure & Scalable Architecture
• Next.js Frontend for User Interaction

📂 Project Structure

monad-bridge
├── contracts # Solidity smart contracts
├── scripts # Hardhat deployment scripts
├── relayer # Node.js relayer service
├── frontend # Next.js frontend
├── hardhat.config.js # Hardhat configuration
├── relayer.js # Relayer event listener
└── README.md # Project documentation

🛠️ Installation & Setup

1️⃣ Clone the Repository

git clone https://github.com/bossonormal215/monad-dapp-test
cd monad-bridge

2️⃣ Install Dependencies

npm install

3️⃣ Configure Environment Variables

Create a .env file in the root directory:

PRIVATE_KEY=your_wallet_private_key
ETH_SEPOLIA_RPC=https://sepolia.infura.io/v3/your_project_id
ARB_SEPOLIA_RPC=https://arb-sepolia.alchemy.com/v2/your_project_id
BASE_SEPOLIA_RPC=https://base-sepolia.infura.io/v3/your_project_id
MONAD_RPC=https://monad-rpc-url
PYTH_ORACLE_ETHEREUM_SEPOLIA=0xYourEthereumSepoliaOracleAddress
PYTH_ORACLE_ARBITRUM_SEPOLIA=0xYourArbitrumSepoliaOracleAddress
PYTH_ORACLE_BASE_SEPOLIA=0xYourBaseSepoliaOracleAddress
PYTH_ORACLE_MONAD_TESTNET=0xYourMonadTestnetOracleAddress

4️⃣ Deploy Smart Contract

npx hardhat run scripts/deploy.js --network sepolia

Repeat for Arbitrum Sepolia and Base Sepolia networks.

5️⃣ Start Relayer Service

node relayer.js

6️⃣ Run Next.js Frontend

cd frontend
npm run dev

🎮 Usage

Deposit ETH

1. Connect Wallet in the frontend.
2. Enter the amount and select a destination chain.
3. Click "Bridge ETH" to send the deposit transaction.
4. The relayer detects the deposit event and processes withdrawal on the destination chain.

Withdraw ETH

• The relayer automatically processes withdrawals after confirming the deposit.

🔍 Architecture

1️⃣ Smart Contract (Solidity)

• Handles deposits and withdrawals
• Uses Pyth Oracle to fetch ETH price
• Emits Deposit events for the relayer

2️⃣ Relayer (Node.js + Ethers.js)

• Listens for deposit events
• Transfers ETH from liquidity pool on the destination chain
• Calls withdraw function on the smart contract

3️⃣ Frontend (Next.js + Ethers.js)

• Provides a simple UI for users to bridge ETH
• Interacts with the smart contract
• Shows transaction status

🛡️ Security Considerations

• Liquidity Management: Ensure the relayer always has enough ETH.
• Oracle Verification: Verify Pyth Oracle prices to prevent manipulation.
• Relayer Safety: Secure the private key of the relayer.

🚀 Future Improvements

• Add more chains (e.g., Optimism, ZkSync)
• Implement slippage protection for bridging fees
• Introduce bridging fees for sustainability
• Enhance UI/UX with transaction history

🤝 Contributing

Want to improve this bridge? Feel free to fork, improve, and create a PR!

git checkout -b feature-branch
git commit -m "Added new feature"
git push origin feature-branch

📜 License

This project is MIT Licensed. Feel free to use and modify it.

🛠️ Built With

• Solidity - Smart contract development
• Hardhat - Ethereum development framework
• Next.js - Frontend framework
• Ethers.js - Ethereum interaction library
• Pyth Oracle - Price feeds

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✨ Made with ❤️ by bossonormal