cowswaprouter

CoW Protocol order routing in Solidity. Deposits tokens into the CoW vault relayer, approves the relayer to pull funds, and triggers batch auction settlement — all in a single transaction. MEV-protected by design: orders settle through CoW Protocol's batch auction rather than directly through an AMM, so there's no on-chain price exposure for front-runners to exploit.

Stack

• Solidity ^0.8.20
• Foundry

Build

forge build

Test

forge test -vv

Deploy

forge create src/cowrouter.sol:CowSwapRouter \
  --constructor-args <relayer_address> <settler_address>

• <relayer_address> — CoW Protocol vault relayer (GPv2VaultRelayer)
• <settler_address> — CoW Protocol settlement contract (GPv2Settlement)

How it works

depositAndSettle(owner, token, amount, orderUid) does four things in sequence:

1. Pull tokens — calls transferFrom(owner, router, amount) to bring the tokens on-chain into the router.
2. Approve relayer — calls approve(cowRelayer, amount) so the CoW vault relayer can move the tokens.
3. Deposit — calls ICowVaultRelayer.deposit(token, owner, amount), registering the funds with CoW's settlement infrastructure.
4. Settle — if orderUid is non-empty, calls ICowSettler.settle(orderUid) to finalize the batch auction order.

The orderUid parameter is optional — pass an empty bytes value to skip settlement and leave the order pending in the CoW batch queue.