CoW Swap (cowswap)

preSignOrder: Pre-sign an order on-chain for execution by solvers
invalidateOrder: Cancel/invalidate a pending order

DEX aggregator using batch auctions and Coincidence of Wants (CoW) to match overlapping orders.

Fact	Value
Category	Aggregators
Family	none
Namespace	`Cowswap` on ethereum, arbitrum
Chains	ethereum, arbitrum

What it offers

Batch auctions match Coincidence of Wants (overlapping orders) first
Orders are typically signed off-chain and submitted to CoW Protocol API
setPreSignature is for smart contracts/multisigs that cannot produce ECDSA signatures
orderUid encodes: order hash + owner address + validTo timestamp
Same settlement contract on both Ethereum and Arbitrum
Approve tokens to the GPv2VaultRelayer (not settlement contract) before trading

On Ethereum, Cowswap is a namespace: its contracts need no import.

function main() {
  // Ethereum's gpv2Settlement, `0x9008D19f58AAbD9eD0D60971565AA8510560ab41`.
  require(Cowswap.GPv2Settlement != 0);
}

Chain	Contract	Address	In a program
Ethereum	gpv2Settlement	`0x9008D19f58AAbD9eD0D60971565AA8510560ab41`	`Cowswap.GPv2Settlement`
Arbitrum One	gpv2Settlement	`0x9008D19f58AAbD9eD0D60971565AA8510560ab41`	`Cowswap.GPv2Settlement`

import GPv2SettlementABI from "./protocols/cowswap/GPv2SettlementABI.json"; Speaks for: gpv2Settlement.