ERC7863 Contributions

Catalyst strives to support and contribute to improving the standard to better support resource locks and make ERC-7683 more future-proof.

General Incompatibilities

ERC-7683 places a lot of focus on the open interface. This makes sense, as the initial version of ERC-7683 was conceived before resource locks. However, with resource locks, it presents a challenge because orders don’t always start with on-chain calls anymore.
The ERC-7683 fill function is expensive because it works with memory, not calldata, due to the transparent bytes provided.

Add address user and uint256 nonce to OnchainCrossChainOrder.
- Goal: To clarify who the depositor is. (Tokens should still be collected from msg.sender.)
Convert the open event into event Open(bytes32 indexed orderId, bytes resolveContext) and add resolve functions that take the original order and resolveContext to accurately produce the ResolvedCrossChainOrder from an off-chain view call.
- Goal: To reduce the cost of emitting the Open event.
Make functions open(...) and openFor(...) optional.
- Goal: To make it explicit that open should only be used for depositing.
Make function validate(...) a view function that returns (uint32 fillDeadline) to easily validate whether an order is valid.
- Goal: To provide an explicit way for pure off-chain orders to be validated.

Additionally, the specification should contain a description of how to integrate the lock flow: outputs first, inputs second.