ERC-4337 (Account Abstraction)

ERC-4337 is the specific Ethereum standard that implements account abstraction (see Kaavon's "Account Abstraction" glossary definition) — letting a smart account (see Kaavon's "Smart Account" glossary definition) initiate transactions with programmable logic, rather than only through a traditional private-key signature — without requiring any changes to Ethereum's core consensus protocol itself. It achieves this through a parallel system of "user operations," a separate mempool for them, and specialized "bundler" nodes that package these operations into a standard transaction a regular Ethereum validator can process without needing any special awareness of account abstraction at all.

This protocol-level-change-free design was a deliberate choice, since achieving the same programmable-account functionality through an actual Ethereum consensus upgrade would have required far more extensive, slower-moving coordination across the entire validator set. ERC-4337 became the practical, widely adopted foundation for smart account wallets precisely because it could be deployed and iterated on without needing the whole network to upgrade first, though a complementary protocol-level change, EIP-7702 (see Kaavon's "EIP-7702" glossary definition), has since added an alternative path to some account-abstraction-like functionality directly at the protocol level.