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API Integration

The CoW Protocol API provides direct access to the protocol's functionality through RESTful endpoints. This approach offers maximum flexibility and control for backend integrations and custom implementations.

Overview​

The API integration allows you to interact with CoW Protocol at the lowest level, giving you complete control over order management, quote fetching, and trade execution. This is ideal for advanced integrations, backend services, and custom trading logic.

Key APIs​

Order Book API​

The primary API for creating and managing orders on CoW Protocol.

  • Base URL: https://api.cow.fi/
  • Purpose: Quote generation, order submission, order management
  • Authentication: No API key required for basic operations

Key Endpoints​

  • POST /api/v1/quote - Get trading quotes
  • POST /api/v1/orders - Submit signed orders
  • GET /api/v1/orders/{uid} - Get order details
  • DELETE /api/v1/orders/{uid} - Cancel orders
  • GET /api/v1/trades - Get trade history

Quick Start Example​

1. Get a Quote​

curl -X POST "https://api.cow.fi/mainnet/api/v1/quote" \
  -H "Content-Type: application/json" \
  -d '{
    "sellToken": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
    "buyToken": "0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2",
    "sellAmountBeforeFee": "1000000000",
    "kind": "sell",
    "from": "0xYourWalletAddress"
  }'

2. Apply Slippage and Sign Order​

Important

Before signing, you must apply slippage tolerance to protect against price movements. See the Quote to Order Tutorial for detailed examples.

import { domain, signOrder, OrderKind, OrderBalance, SigningScheme } from '@cowprotocol/contracts'

// Apply slippage to the quote before signing
// For sell orders: reduce buyAmount by slippage (e.g., 0.5%)
const buyAmountWithSlippage = BigInt(quoteResponse.quote.buyAmount) * 995n / 1000n

// Build order object for signing (uses enums, not strings)
const order = {
  ...quoteResponse.quote,
  buyAmount: buyAmountWithSlippage.toString(),
  receiver: walletAddress,
  kind: OrderKind.SELL,
  sellTokenBalance: OrderBalance.ERC20,
  buyTokenBalance: OrderBalance.ERC20,
}

// Sign using @cowprotocol/contracts
const orderDomain = domain(1, '0x9008D19f58AAbD9eD0D60971565AA8510560ab41')
const signature = await signOrder(orderDomain, order, signer, SigningScheme.EIP712)

// Submit - API expects strings for kind/balance fields
const response = await fetch('https://api.cow.fi/mainnet/api/v1/orders', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    ...quoteResponse.quote,
    buyAmount: buyAmountWithSlippage.toString(),
    receiver: walletAddress,
    signature: signature.data,
    signingScheme: 'eip712',
    from: walletAddress
  })
})

const orderId = await response.text()

3. Monitor Order Status​

// Check order status
const orderResponse = await fetch(
  `https://api.cow.fi/mainnet/api/v1/orders/${orderId}`
)
const orderDetails = await orderResponse.json()

console.log('Order status:', orderDetails.status)

Network Endpoints​

CoW Protocol APIs are available on multiple networks:

  • Mainnet: https://api.cow.fi/mainnet/api/v1/
  • Gnosis Chain: https://api.cow.fi/xdai/api/v1/
  • Arbitrum: https://api.cow.fi/arbitrum_one/api/v1/
  • Base: https://api.cow.fi/base/api/v1/
  • Sepolia (Testnet): https://api.cow.fi/sepolia/api/v1/

Order Signing​

Orders must be cryptographically signed before submission. The signing process involves:

  1. EIP-712 Domain: Chain-specific domain separator
  2. Order Struct: Structured order data
  3. Signature: ECDSA signature or pre-signed order
import { ethers } from 'ethers'

// Example order signing with ethers.js
const domain = {
  name: 'Gnosis Protocol',
  version: 'v2',
  chainId: 1,
  verifyingContract: '0x9008D19f58AAbD9eD0D60971565AA8510560ab41'
}

const types = {
  Order: [
    { name: 'sellToken', type: 'address' },
    { name: 'buyToken', type: 'address' },
    { name: 'receiver', type: 'address' },
    // ... other order fields
  ]
}

const signature = await signer._signTypedData(domain, types, orderData)

Error Handling​

The API returns standard HTTP status codes:

  • 200: Success
  • 400: Bad Request (invalid parameters)
  • 404: Order not found
  • 429: Rate limited
  • 500: Internal server error
try {
  const response = await fetch(apiUrl, requestOptions)

  if (!response.ok) {
    const error = await response.json()
    throw new Error(`API Error: ${error.description}`)
  }

  return await response.json()
} catch (error) {
  console.error('Order submission failed:', error)
}

When to Use the API​

  • Backend integration: Server-side order management
  • Custom trading logic: Advanced order types and strategies
  • High-frequency trading: Programmatic order placement
  • Multi-chain applications: Cross-chain arbitrage and liquidity
  • Analytics platforms: Order and trade data analysis

Rate Limits​

  • Quote requests: 10 requests/second
  • Order submission: 5 requests/second
  • General endpoints: 100 requests/minute

Next Steps​

For complete API documentation including all endpoints, parameters, and response schemas, see:

Resources​