Orders
The Order interface represents a Gnosis Protocol v2 order with specific required fields for signing and settlement.
Order Interface
interface Order {
sellToken: string;
buyToken: string;
receiver: string;
sellAmount: BigNumberish;
buyAmount: BigNumberish;
validTo: number | Date;
appData: string;
feeAmount: BigNumberish;
kind: OrderKind;
partiallyFillable: boolean;
sellTokenBalance?: OrderBalance;
buyTokenBalance?: OrderBalance;
}
Order Types
Sell Orders
Specify an exact amount to sell with a minimum amount to receive:
const sellOrder: Order = {
sellToken: WETH,
buyToken: DAI,
sellAmount: ethers.utils.parseEther("1.0"), // Exact
buyAmount: ethers.utils.parseEther("2000"), // Minimum
kind: OrderKind.SELL,
// ...
};
Buy Orders
Specify an exact amount to receive with a maximum to spend:
const buyOrder: Order = {
sellToken: WETH,
buyToken: DAI,
sellAmount: ethers.utils.parseEther("1.1"), // Maximum
buyAmount: ethers.utils.parseEther("2000"), // Exact
kind: OrderKind.BUY,
// ...
};
Balance Management
Three balance modes are supported:
| Mode | Enum | Description |
|---|
| Standard | OrderBalance.ERC20 | Standard ERC20 token transfers |
| External | OrderBalance.EXTERNAL | Balancer Vault external balances |
| Internal | OrderBalance.INTERNAL | Balancer Vault internal balances |
Utility Functions
normalizeOrder
Prepares orders for EIP-712 signing by converting Date objects to timestamps and normalizing optional fields.
import { normalizeOrder } from "@cowprotocol/contracts";
const normalized = normalizeOrder(order);
hashOrder
Generates the EIP-712 hash needed for cryptographic signing.
import { hashOrder, domain } from "@cowprotocol/contracts";
const settlementDomain = domain(1, "0x9008D19f58AAbD9eD0D60971565AA8510560ab41");
const hash = hashOrder(settlementDomain, order);
computeOrderUid
Creates a 56-byte unique identifier combining order digest, owner address, and expiration.
import { computeOrderUid } from "@cowprotocol/contracts";
const uid = computeOrderUid(settlementDomain, order, ownerAddress);
import { extractOrderUidParams } from "@cowprotocol/contracts";
const { orderDigest, owner, validTo } = extractOrderUidParams(uid);
Constants
// Special address for purchasing native ETH (use only in buyToken field)
const BUY_ETH_ADDRESS = "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE";
// Order UID length in bytes
const ORDER_UID_LENGTH = 56;
BUY_ETH_ADDRESS should only be used in the buyToken field. Using it elsewhere will cause unexpected behavior.
