Account Abstraction (ERC-4337)

Account abstraction lets every wallet behave like a smart contract account, so the rules for validating a transaction are written in code instead of being fixed by the protocol. On Ethereum the ERC-4337 standard delivers this without changing the base layer: wallets send user operations to a separate mempool, where bundlers package them and an entry point contract verifies them. It enables paying gas in tokens or having a sponsor cover it, batching several actions into one confirmation, session keys for apps, and recovery without a seed phrase. Added moving parts bring added surface: bundlers, paymasters and the account contract itself must be trusted or audited, and support still varies between chains and applications.