ERC-4337

ERC-4337 delivers account abstraction without touching the consensus layer or adding a new protocol-level transaction type. Instead of signing a normal transaction, the user signs a pseudo-transaction called a UserOperation that expresses their intent and travels through a dedicated mempool. A bundler node listens to that mempool, batches several UserOperations and submits them in a single on-chain transaction to the EntryPoint, a singleton contract that validates and executes each operation against the user's account. That account is a smart contract (a contract account), which allows arbitrary validation logic such as multisig, social recovery or session keys. The terms are worth separating: account abstraction is the idea, ERC-4337 is a concrete fork-free implementation.

The piece that changes the experience is the Paymaster, an optional contract that applies gas-payment policies. It lets users pay gas in stablecoins like USDC instead of native ETH, or lets an issuer sponsor gas entirely so the end user never has to manage it. The Aggregator component bundles and validates signatures, for example BLS signatures. The result is the UX foundation for onboarding at scale and for any tokenization platform to abstract away gas friction, which is especially useful on L2 where bundling costs less.

The standard reached Final status in March 2023, and its reference EntryPoint implementation was deployed to Ethereum mainnet on 1 March 2023, with an author team that includes Vitalik Buterin, Yoav Weiss, Dror Tirosh and Alex Forshtat, among others. OpenZeppelin ships an ERC-4337-compliant Account Abstraction module in its Contracts 5.x, and providers such as Alchemy and Blocknative run bundler and paymaster infrastructure. A typical case is a paymaster that lets users pay gas in Circle's USDC.