> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cow.bleu.builders/llms.txt
> Use this file to discover all available pages before exploring further.

# Order

> TypeScript order module API for creating, hashing, and managing CoW Protocol orders

# Order

The Order module provides structures and utilities for managing CoW Protocol orders, including creation, hashing, and management functions.

## Types

### Order

```typescript theme={null}
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;
}
```

### OrderKind

```typescript theme={null}
enum OrderKind {
  SELL = "sell",
  BUY = "buy",
}
```

* **SELL** - Exact sell amount with minimum buy amount guaranteed
* **BUY** - Exact buy amount with maximum sell amount capped

### OrderBalance

```typescript theme={null}
enum OrderBalance {
  ERC20 = "erc20",
  EXTERNAL = "external",
  INTERNAL = "internal",
}
```

* **ERC20** - Standard ERC20 token balances
* **EXTERNAL** - Balancer Vault external balances
* **INTERNAL** - Balancer Vault internal balances

## Functions

### normalizeOrder

Prepares orders for EIP-712 hashing by converting Date objects to timestamps and normalizing optional fields.

```typescript theme={null}
function normalizeOrder(order: Order): NormalizedOrder;
```

### hashOrder

Generates the EIP-712 signing hash for an order.

```typescript theme={null}
function hashOrder(domain: TypedDataDomain, order: Order): string;
```

### computeOrderUid

Creates a unique 56-byte order identifier combining order digest, owner address, and expiration.

```typescript theme={null}
function computeOrderUid(
  domain: TypedDataDomain,
  order: Order,
  owner: string
): string;
```

### extractOrderUidParams

Decodes order UID components back into individual parameters.

```typescript theme={null}
function extractOrderUidParams(
  orderUid: string
): {
  orderDigest: string;
  owner: string;
  validTo: number;
};
```

## Constants

```typescript theme={null}
const BUY_ETH_ADDRESS = "0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE";
const ORDER_UID_LENGTH = 56;
```

<Note>
  `BUY_ETH_ADDRESS` enables purchasing native ETH and should only be used in the `buyToken` field.
</Note>

## Example

```typescript theme={null}
import { domain, Order, OrderKind, hashOrder, computeOrderUid } from "@cowprotocol/contracts";
import { ethers } from "ethers";

const settlementDomain = domain(1, "0x9008D19f58AAbD9eD0D60971565AA8510560ab41");

const order: Order = {
  sellToken: "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
  buyToken: "0x6B175474E89094C44Da98b954EedeAC495271d0F",
  sellAmount: ethers.utils.parseEther("1.0"),
  buyAmount: ethers.utils.parseEther("2000"),
  validTo: Math.floor(Date.now() / 1000) + 3600,
  appData: ethers.constants.HashZero,
  feeAmount: ethers.utils.parseEther("0.01"),
  kind: OrderKind.SELL,
  partiallyFillable: false,
  receiver: ethers.constants.AddressZero,
};

const orderHash = hashOrder(settlementDomain, order);
const orderUid = computeOrderUid(settlementDomain, order, "0xYourAddress");
```