Optimism Bridge Examples

Simple examples for bridging assets between Ethereum L1 (Sepolia) and Optimism L2 (Optimism Sepolia) using the OP Stack.

🚀 Quick Start

1. Install dependencies

   yarn install

2. Set up environment

   cp .env.example .env
   # Edit .env with your private key

3. Run examples

   # Deposit native ETH from L1 to L2
   yarn native-deposit
   
   # Deposit ERC20 tokens from L1 to L2
   yarn erc20-deposit
   
   # Withdraw native ETH from L2 to L1
   yarn native-withdrawal
   
   # Withdraw ERC20 tokens from L2 to L1
   yarn erc20-withdrawal
   
   # Check withdrawal status
   yarn withdrawal-status

📁 Project Structure

src/
├── config/
│   ├── clients.ts      # Viem clients configuration
│   ├── erc20ABI.ts     # ERC20 contract ABI
│   └── logger.ts       # Logging utility
├── parentToChild/      # L1 → L2 operations
│   ├── nativeDeposit.ts
│   └── erc20Deposit.ts
├── childToParent/      # L2 → L1 operations
│   ├── nativeWithdrawal.ts
│   └── erc20Withdrawal.ts
└── getWithdrawlStatus/
    └── index.ts        # Check withdrawal status

🔧 Configuration

Environment Variables

Create a .env file in the root directory:

PRIVATE_KEY=your_private_key_here

Networks

• L1 & L2 : Configure networks in config/clients.ts

📝 Available Scripts

Script	Description
yarn native-deposit	Deposit native ETH from L1 to L2
yarn erc20-deposit	Deposit ERC20 tokens from L1 to L2
yarn native-withdrawal	Withdraw native ETH from L2 to L1
yarn erc20-withdrawal	Withdraw ERC20 tokens from L2 to L1
yarn withdrawal-status	Check withdrawal status

🔄 Bridge Process

Deposits (L1 → L2)

1. Native ETH: Single transaction, instant on L2
2. ERC20: Two transactions (approve + deposit), instant on L2

Withdrawals (L2 → L1)

1. Initiate: Submit withdrawal on L2
2. Prove: Prove withdrawal on L1
3. Finalize: Finalize withdrawal on L1

Dependencies

• @eth-optimism/viem: Optimism-specific Viem actions
• viem: Ethereum client library
• typescript: Type safety

📚 Resources

• Optimism Documentation
• Viem Documentation

🤝 Contributing

Feel free to submit issues and enhancement requests!