Glossary
ERC-4337
Account abstraction on Ethereum without protocol changes: smart-contract wallets, gas sponsorship, and custom signatures via a separate user-operation mempool.
Until ERC-4337, every Ethereum transaction had to be signed by an
externally-owned account (an ECDSA keypair). ERC-4337 introduces
UserOperation — a pseudo-transaction sent to a parallel mempool —
that a "Bundler" packages into a regular transaction calling a
canonical EntryPoint contract.
The smart-contract wallet itself defines validation: multisig, social recovery, passkeys, paying gas in a stablecoin via a Paymaster, batched calls. All of this lands without any change to the L1 protocol.