Build on the Wormhole Liquidity Layer＃

Introduction＃

The Wormhole Liquidity Layer is the underlying chain abstraction infrastructure layer for protocols across Wormhole-connected ecosystems. It allows these protocols to bundle call data containing arbitrary actions that can be executed atomically alongside each transfer. This feature enables developers to create fully chain-abstracted user experiences, including constructing natively cross-chain decentralized exchanges (DEXs), borrow-lend protocols, payment protocols, and other applications atop this layer. The following section describes the key smart contract components for teams seeking to build atop Wormhole Settlement.

EVM Functions＃

The EVM Token Router is a simple interface against which to integrate. For an integrator, the contracts have two main entry points: placeMarketOrder and placeFastMarketOrder.

Fast Market Order＃

The placeFastMarketOrder function allows the caller to elect for a faster-than-finality transfer of USDC (with an arbitrary message payload) to the destination chain by setting the maxFee and deadline parameters. Using this interface does not guarantee that the caller's transfer will be delivered faster than finality; however, any willing market participants can compete for the specified maxFee by participating in an auction on the Solana MatchingEngine

`placeFastMarketOrder` interface

function placeFastMarketOrder(
    uint128 amountIn,
    uint16 targetChain,
    bytes32 redeemer,
    bytes calldata redeemerMessage,
    uint128 maxFee,
    uint32 deadline
) external payable returns (uint64 sequence, uint64 fastSequence);

Parameters placeFastMarketOrder()

amountIn uint128

The amount to transfer.

targetChain uint16

Target chain ID.

redeemer bytes32

Redeemer contract address.

redeemerMessage bytes

An arbitrary payload for the redeemer.

maxFee uint128

The maximum fee the user wants to pay to execute a fast transfer.

deadline uint32

The deadline for the fast transfer auction to start. Note: This timestamp should be for the MatchingEngine chain (such as Solana) to avoid any clock drift issues between different blockchains. Integrators can set this value to 0 if they don't want to use a deadline.

The placeFastMarketOrder function returns a sequence number for the Wormhole Fill message. This function requires the caller to provide a msg.value equal to the amount returned by the messageFee() function on the IWormhole.sol interface.

Market Order＃

The placeMarketOrder function is a wait-for-full-finality USDC transfer with an arbitrary message payload. The Swap Layer, built on top of the Wormhole Settlement, uses this function if the auction on the matching engine for placeFastMarketOrder doesn't start within a specific deadline.

`placeMarketOrder` interface

function placeMarketOrder(
    uint128 amountIn,
    uint16 targetChain,
    bytes32 redeemer,
    bytes calldata redeemerMessage,
) external payable returns (uint64 sequence, uint64 protocolSequence);

Parameters placeMarketOrder()