GPv2Settlement

The main settlement contract for executing CoW Protocol batch trades

GPv2Settlement Contract

The GPv2Settlement contract serves as CoW Protocol’s core infrastructure, inheriting from GPv2Signing, ReentrancyGuard, and StorageAccessible to enable batch settlements and order validation.

Source: src/contracts/GPv2Settlement.sol License: LGPL-3.0-or-later Solidity: >=0.7.6 <0.9.0

State Variables

Immutable

Variable	Type	Description
authenticator	GPv2Authentication	Determines solver authorization
vault	IVault	Balancer Vault for fund management
vaultRelayer	GPv2VaultRelayer	Enables vault interactions on behalf of users

Storage

Variable	Type	Description
filledAmount	mapping(bytes => uint256)	Tracks per-order fill amounts to prevent over-filling

Primary Functions

settle()

Executes batch orders at uniform clearing prices with pre/intra/post-settlement interactions.

function settle(
    IERC20[] calldata tokens,
    uint256[] calldata clearingPrices,
    GPv2Trade.Data[] calldata trades,
    GPv2Interaction.Data[][3] calldata interactions
) external nonReentrant onlySolver;

swap()

Matches orders directly against Balancer V2 pools for optimized single-pool trades.

function swap(
    IVault.SingleSwap calldata swap,
    GPv2Trade.Data calldata trade
) external nonReentrant onlySolver returns (int256);

invalidateOrder()

Allows order owners to revoke on-chain orders by invalidating the order UID.

function invalidateOrder(bytes calldata orderUid) external;

Storage Cleanup

Gas refund functions for expired orders:

function freeFilledAmountStorage(bytes[] calldata orderUids) external;
function freePreSignatureStorage(bytes[] calldata orderUids) external;

Settlement Execution Flow

Security Protections

• All orders include a validTo timestamp checked on execution
• Filled amount tracking prevents over-filling
• Limit price validation ensures trades respect order parameters
• Solver authorization restricts settlement access via onlySolver modifier
• nonReentrant modifier prevents reentrancy attacks