While, off-chain orderbook based exchanges have been around for a long time, these has gradually moved to L2 networks to improve efficacy of order handling. With the introduction of ERC4337 Account Abstraction standard, it makes it possible to have a fully self-custodial exchange wallet with an off-chain orderbook. Meaning, users are guaranteed of the safety of their funds while on exchange, and that the exchange will not be able to withdraw their funds maliciously.

To do this, we introduce a new ERC standard for Multi-User Self Custodial Accounts that can be used by offchain orderbook exchanges and order matching algorithms. Further, because this is based on the ERC4337 standard, these spot swaps can be matched in batches reducing order handling costs for user.

The end result is better UX for users already familiar with CEX exchanges, and frustrated by swapping on AMM DEXs.