Recipe: Wrap and unwrap ETH (WETH) programmatically

[PetarStoev02]

Description

Recipe showing how to wrap ETH into WETH and unwrap it back — the gateway operation for almost every DeFi interaction.

Why this matters

Native ETH doesn't conform to the ERC-20 standard, but DeFi protocols need ERC-20 tokens. WETH (Wrapped ETH) solves this. Before you can deposit into Aave, swap on Uniswap, or provide liquidity — you often need WETH. It's the first step in any DeFi workflow.

Scope

• Deposit ETH → get WETH (wrap)
• Withdraw WETH → get ETH back (unwrap)
• Check WETH balance
• WETH contract addresses per chain
• When you need WETH vs when protocols auto-wrap for you
• Gas cost comparison: wrap vs direct ETH operations

w3-kit approach

• Simple, clean viem pattern
• Explain WHY WETH exists (ERC-20 compatibility)
• Multi-chain WETH addresses from w3-kit registry
• Integration with other DeFi recipes

Acceptance criteria

• Recipe in recipes/evm/
• Wrap and unwrap examples
• Multi-chain WETH addresses
• .learn.md explaining the WETH contract (deposit/withdraw pattern, why ETH isn't ERC-20)

[github-actions]

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