LayerZero Integration

iLayer is a multi-layered protocol for intent-based transactions, leveraging advanced solvers to provide fast, efficient liquidity for dApps.

For this audit, the Cross-chain Orderbook subsystem was audited, also referred to as iLayer Core and its integration with LayerZero for cross-chain messaging.

The Cross-chain Orderbook is a decentralized transaction matching engine, designed to align user intents with solvers. Users create orders on one chain, with filling to be done on another, and fillers (sometimes arbitrary) complete them for a part of the order as a slippage equivalent.

The orderbook is composed of two main components:

• OrderHub: The main entry point of the system. Users can create their orders via the order hub. The hub then passes the order ID, through LayerZero, to the settling chain, to signal fillers that an order is available.
• OrderSpoke: Receives the order from the order hub via LayerZero, fills the order, and then initiates the settling on the OrderHub contract; again, through LZ.

The orderbook can work with Native tokens, ERC-20, ERC-721 and ERC-1155 tokens and also offers gasless transactions by using EIP-712 signatures and ERC-2612 permit-compatible tokens.

As a result of the current audit, support for meta-transactions (ERC-2771) was added.