Ethereum Upgrade Enables Programmable EOAs

A recent Ethereum upgrade has enabled programmable Externally Owned Accounts (EOAs) through the Pectra upgrade, which activated on May 7, 2025.

This new functionality allows EOAs to temporarily assume the behavior of smart contracts using a new transaction type that includes an 'authorization_list'. Each tuple contains a chain ID, contract address, nonce, and ECDSA signature.

The network writes a delegation indicator to the EOA's code with a 20-byte contract address. This indicator uses the prefix 0xef0100 followed by the magic prefix, chain ID, address, and nonce. The signature includes y_parity, r, and s elements, incrementing the EOA's nonce before execution begins.

Within the first week of the upgrade, 15,000 EIP-7702 delegations appeared on Ethereum mainnet. This follows the activation of 4 million smart contract wallets in September. Traditional EOAs are lightweight but limited, unable to respond to inputs like receiving tokens or pay gas in anything other than the chain's native token.

EIP-7702 and ERC-4337 work together to improve user experience by onboarding existing EOAs to the ERC-4337 infrastructure, including bundlers and paymasters. However, adopting existing smart contract wallets built before EIP-7702 is dangerous due to lack of support for initialization code or storage management.