Basic Swap Example

This example demonstrates how to create a basic swap order using the CoW Protocol SDK. We’ll swap WETH for USDC on Sepolia testnet.

Prerequisites

Node.js installed
A wallet with some testnet ETH
An Ethereum provider (RPC endpoint)

Installation

npm install @cowprotocol/cow-sdk ethers

Complete Example

import { JsonRpcProvider, Wallet } from 'ethers'
import {
  setGlobalAdapter,
  SupportedChainId,
  TradingSdk,
  OrderKind,
  WRAPPED_NATIVE_CURRENCIES,
} from '@cowprotocol/cow-sdk'
import { EthersV6Adapter } from '@cowprotocol/sdk-ethers-v6-adapter'

// Configuration
const RPC_URL = 'https://sepolia.gateway.tenderly.co'
const PRIVATE_KEY = '0x...' // Your private key
const DEFAULT_SELL_AMOUNT = '0.1' // WETH amount

async function main() {
  const chainId = SupportedChainId.SEPOLIA

  // Setup provider and wallet
  const provider = new JsonRpcProvider(RPC_URL, chainId)
  const wallet = new Wallet(PRIVATE_KEY, provider)

  // Setup CoW Protocol adapter
  const adapter = new EthersV6Adapter({ provider, signer: wallet })
  setGlobalAdapter(adapter)

  // Initialize Trading SDK
  const sdk = new TradingSdk({
    chainId,
    appCode: 'MyApp',
    signer: wallet,
  })

  // Define tokens
  const WETH = WRAPPED_NATIVE_CURRENCIES[chainId]
  const USDC = {
    address: '0xbe72E441BF55620febc26715db68d3494213D8Cb',
    decimals: 18,
  }

  const owner = (await wallet.getAddress()) as `0x${string}`
  const amount = Math.round(
    Number(DEFAULT_SELL_AMOUNT) * 10 ** WETH.decimals
  ).toString()
  const slippageBps = 50 // 0.5% slippage

  console.log('Owner:', owner)
  console.log('Getting quote...')

  // Get quote
  const quoteAndPost = await sdk.getQuote({
    chainId,
    kind: OrderKind.SELL,
    owner,
    amount,
    sellToken: WETH.address,
    sellTokenDecimals: WETH.decimals,
    buyToken: USDC.address,
    buyTokenDecimals: USDC.decimals,
    slippageBps,
  })

  console.log('Quote received:', quoteAndPost.quoteResults)

  // Post the order
  console.log('Posting order...')
  const result = await quoteAndPost.postSwapOrderFromQuote({})
  console.log('Order posted successfully!')
  console.log('Order ID:', result.orderId)
}

main().catch((e) => {
  console.error(e)
  process.exit(1)
})

import { ethers } from 'ethers'
import {
  setGlobalAdapter,
  SupportedChainId,
  TradingSdk,
  OrderKind,
  WRAPPED_NATIVE_CURRENCIES,
} from '@cowprotocol/cow-sdk'
import { EthersV5Adapter } from '@cowprotocol/sdk-ethers-v5-adapter'

const RPC_URL = 'https://sepolia.gateway.tenderly.co'
const PRIVATE_KEY = '0x...' // Your private key
const DEFAULT_SELL_AMOUNT = '0.1'

async function main() {
  const chainId = SupportedChainId.SEPOLIA

  const provider = new ethers.providers.JsonRpcProvider(RPC_URL, chainId)
  const wallet = new ethers.Wallet(PRIVATE_KEY, provider)

  const adapter = new EthersV5Adapter({ provider, signer: wallet })
  setGlobalAdapter(adapter)

  const sdk = new TradingSdk({
    chainId,
    appCode: 'MyApp',
    signer: wallet,
  })

  const WETH = WRAPPED_NATIVE_CURRENCIES[chainId]
  const USDC = {
    address: '0xbe72E441BF55620febc26715db68d3494213D8Cb',
    decimals: 18,
  }

  const owner = (await wallet.getAddress()) as `0x${string}`
  const amount = Math.round(
    Number(DEFAULT_SELL_AMOUNT) * 10 ** WETH.decimals
  ).toString()
  const slippageBps = 50

  console.log('Owner:', owner)
  console.log('Getting quote...')

  const quoteAndPost = await sdk.getQuote({
    chainId,
    kind: OrderKind.SELL,
    owner,
    amount,
    sellToken: WETH.address,
    sellTokenDecimals: WETH.decimals,
    buyToken: USDC.address,
    buyTokenDecimals: USDC.decimals,
    slippageBps,
  })

  console.log('Posting order...')
  const result = await quoteAndPost.postSwapOrderFromQuote({})
  console.log('Posted:', result)
}

main().catch((e) => {
  console.error(e)
  process.exit(1)
})

import { createPublicClient, http } from 'viem'
import { privateKeyToAccount } from 'viem/accounts'
import { sepolia } from 'viem/chains'
import {
  setGlobalAdapter,
  SupportedChainId,
  TradingSdk,
  OrderKind,
  WRAPPED_NATIVE_CURRENCIES,
} from '@cowprotocol/cow-sdk'
import { ViemAdapter } from '@cowprotocol/sdk-viem-adapter'

const RPC_URL = 'https://sepolia.gateway.tenderly.co'
const PRIVATE_KEY = '0x...' // Your private key
const DEFAULT_SELL_AMOUNT = 0.1

async function main() {
  const chainId = SupportedChainId.SEPOLIA

  // Create public client
  const publicClient = createPublicClient({
    chain: sepolia,
    transport: http(RPC_URL),
  })

  // Create account from private key
  const account = privateKeyToAccount(PRIVATE_KEY as `0x${string}`)

  // Setup adapter
  const adapter = new ViemAdapter({ provider: publicClient, signer: account })
  setGlobalAdapter(adapter)

  // Initialize SDK
  const sdk = new TradingSdk({
    chainId,
    appCode: 'MyApp',
    signer: account,
  })

  const WETH = WRAPPED_NATIVE_CURRENCIES[chainId]
  const USDC = {
    address: '0xbe72E441BF55620febc26715db68d3494213D8Cb',
    decimals: 18,
  }

  const owner = account.address
  const amount = BigInt(Math.floor(DEFAULT_SELL_AMOUNT * 10 ** WETH.decimals))
  const slippageBps = 50

  console.log('Owner:', owner)
  console.log('Getting quote...')

  const quoteAndPost = await sdk.getQuote({
    chainId,
    kind: OrderKind.SELL,
    owner,
    amount: amount.toString(),
    sellToken: WETH.address,
    sellTokenDecimals: WETH.decimals,
    buyToken: USDC.address,
    buyTokenDecimals: USDC.decimals,
    slippageBps,
  })

  console.log('Posting order...')
  const result = await quoteAndPost.postSwapOrderFromQuote({})
  console.log('Posted:', result)
}

main().catch((e) => {
  console.error(e)
  process.exit(1)
})

Understanding the Code

1. Setup the Adapter

The adapter connects the SDK to your Ethereum provider:

const adapter = new EthersV6Adapter({ provider, signer: wallet })
setGlobalAdapter(adapter)

2. Initialize the Trading SDK

const sdk = new TradingSdk({
  chainId: SupportedChainId.SEPOLIA,
  appCode: 'MyApp', // Your app identifier
  signer: wallet,
})

3. Get a Quote

Request a quote for the swap:

const quoteAndPost = await sdk.getQuote({
  chainId,
  kind: OrderKind.SELL, // Selling exact amount
  owner,
  amount,
  sellToken: WETH.address,
  sellTokenDecimals: WETH.decimals,
  buyToken: USDC.address,
  buyTokenDecimals: USDC.decimals,
  slippageBps: 50, // 0.5% slippage tolerance
})

4. Post the Order

const result = await quoteAndPost.postSwapOrderFromQuote({})
console.log('Order ID:', result.orderId)

Quote Results

The quote contains important information:

const { quoteResults } = quoteAndPost

// Get buy amount after fees
const buyAmount = quoteResults.amountsAndCosts.afterNetworkCosts.buyAmount

// Check network costs
const networkCosts = quoteResults.amountsAndCosts.networkCosts

// View order data
const orderData = quoteResults.orderToSign

Error Handling

Always wrap SDK calls in try-catch blocks:

try {
  const quoteAndPost = await sdk.getQuote(params)
  const result = await quoteAndPost.postSwapOrderFromQuote({})
} catch (error) {
  console.error('Swap failed:', error)
  // Handle specific error types
  if (error.message.includes('insufficient balance')) {
    console.error('Insufficient token balance')
  }
}

Next Steps

Learn about limit orders
Integrate with React
Explore swap order guide

Getting Started

Concepts

Guides

Advanced

Examples

API Reference

Migration

Basic Swap

Basic Swap Example

Prerequisites

Installation

Complete Example

Understanding the Code

1. Setup the Adapter

2. Initialize the Trading SDK

3. Get a Quote

4. Post the Order

Quote Results

Error Handling

Next Steps

​Basic Swap Example

​Prerequisites

​Installation

​Complete Example

​Understanding the Code

​1. Setup the Adapter

​2. Initialize the Trading SDK

​3. Get a Quote

​4. Post the Order

​Quote Results

​Error Handling

​Next Steps

Basic Swap Example

Prerequisites

Installation

Complete Example

Understanding the Code

1. Setup the Adapter

2. Initialize the Trading SDK

3. Get a Quote

4. Post the Order

Quote Results

Error Handling

Next Steps