Core Contract Addresses (Ethereum Mainnet)

• SwapRouter02: 0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45
• NonfungiblePositionManager: 0xC36442b4a4522E871399CD717aBDD847Ab11FE88
• Quoter V2: 0x61fFE014bA17989E743c5F6cB21bF9697530B21e
• Factory: 0x1F98431c8aD98523631AE4a59f267346ea31F984

Install SDK

npm install @uniswap/v3-sdk @uniswap/sdk-core
npm install @uniswap/smart-order-router  # auto routing

Execute a Swap (minimal path)

import { ethers } from 'ethers'

const SWAP_ROUTER = '0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45'
const swapRouterABI = [
  'function exactInputSingle((address tokenIn, address tokenOut, uint24 fee, address recipient, uint256 amountIn, uint256 amountOutMinimum, uint160 sqrtPriceLimitX96) params) external payable returns (uint256 amountOut)'
]

async function swapExactInput(signer, tokenIn, tokenOut, amountIn, minOut) {
  // 1. Approve
  const token = new ethers.Contract(tokenIn, ['function approve(address,uint256)'], signer)
  await token.approve(SWAP_ROUTER, amountIn)
  
  // 2. Swap
  const router = new ethers.Contract(SWAP_ROUTER, swapRouterABI, signer)
  return router.exactInputSingle({
    tokenIn, tokenOut,
    fee: 3000,          // 0.3% — most commonly used fee tier
    recipient: await signer.getAddress(),
    amountIn,
    amountOutMinimum: minOut,
    sqrtPriceLimitX96: 0
  })
}

Fee Tiers

Get a Price Quote

const quoterABI = ['function quoteExactInputSingle((address tokenIn, address tokenOut, uint256 amountIn, uint24 fee, uint160 sqrtPriceLimitX96) params) external returns (uint256 amountOut, uint160 sqrtPriceX96After, uint32 initializedTicksCrossed, uint256 gasEstimate)']
const quoter = new ethers.Contract('0x61fFE014bA17989E743c5F6cB21bF9697530B21e', quoterABI, provider)

const [amountOut] = await quoter.quoteExactInputSingle.staticCall({
  tokenIn: WETH, tokenOut: USDC, amountIn: ethers.parseEther('1'), fee: 3000, sqrtPriceLimitX96: 0
})

Using the Smart Order Router (optimal path auto-routing)

import { AlphaRouter, SwapType } from '@uniswap/smart-order-router'
import { CurrencyAmount, TradeType, Percent } from '@uniswap/sdk-core'

const router = new AlphaRouter({ chainId: 1, provider })
const route = await router.route(
  CurrencyAmount.fromRawAmount(WETH_TOKEN, amountIn.toString()),
  USDC_TOKEN,
  TradeType.EXACT_INPUT,
  { slippageTolerance: new Percent(50, 10_000), deadline: Math.floor(Date.now()/1000) + 180, type: SwapType.SWAP_ROUTER_02, recipient }
)
// route.methodParameters.calldata — send directly

Adding Liquidity (Position Manager)

const NPM_ABI = ['function mint((address token0, address token1, uint24 fee, int24 tickLower, int24 tickUpper, uint256 amount0Desired, uint256 amount1Desired, uint256 amount0Min, uint256 amount1Min, address recipient, uint256 deadline)) external returns (uint256 tokenId, uint128 liquidity, uint256 amount0, uint256 amount1)']

// tick calculation: price → tick = Math.floor(Math.log(price) / Math.log(1.0001))

Common Pitfalls

• Setting amountOutMinimum to 0 exposes you to sandwich attacks — set it to at least 95% of the expected output
• Use staticCall for the Quoter — do not send it as a real transaction
• Always set a deadline to prevent transactions from waiting indefinitely in the mempool

Uniswap V3 Integration Guide

Core Contract Addresses (Ethereum Mainnet)

• SwapRouter02: 0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45
• NonfungiblePositionManager: 0xC36442b4a4522E871399CD717aBDD847Ab11FE88
• Quoter V2: 0x61fFE014bA17989E743c5F6cB21bF9697530B21e
• Factory: 0x1F98431c8aD98523631AE4a59f267346ea31F984

Install SDK

npm install @uniswap/v3-sdk @uniswap/sdk-core
npm install @uniswap/smart-order-router  # auto routing

Execute a Swap (minimal path)

import { ethers } from 'ethers'

const SWAP_ROUTER = '0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45'
const swapRouterABI = [
  'function exactInputSingle((address tokenIn, address tokenOut, uint24 fee, address recipient, uint256 amountIn, uint256 amountOutMinimum, uint160 sqrtPriceLimitX96) params) external payable returns (uint256 amountOut)'
]

async function swapExactInput(signer, tokenIn, tokenOut, amountIn, minOut) {
  // 1. Approve
  const token = new ethers.Contract(tokenIn, ['function approve(address,uint256)'], signer)
  await token.approve(SWAP_ROUTER, amountIn)
  
  // 2. Swap
  const router = new ethers.Contract(SWAP_ROUTER, swapRouterABI, signer)
  return router.exactInputSingle({
    tokenIn, tokenOut,
    fee: 3000,          // 0.3% — most commonly used fee tier
    recipient: await signer.getAddress(),
    amountIn,
    amountOutMinimum: minOut,
    sqrtPriceLimitX96: 0
  })
}

Fee Tiers

Get a Price Quote

const quoterABI = ['function quoteExactInputSingle((address tokenIn, address tokenOut, uint256 amountIn, uint24 fee, uint160 sqrtPriceLimitX96) params) external returns (uint256 amountOut, uint160 sqrtPriceX96After, uint32 initializedTicksCrossed, uint256 gasEstimate)']
const quoter = new ethers.Contract('0x61fFE014bA17989E743c5F6cB21bF9697530B21e', quoterABI, provider)

const [amountOut] = await quoter.quoteExactInputSingle.staticCall({
  tokenIn: WETH, tokenOut: USDC, amountIn: ethers.parseEther('1'), fee: 3000, sqrtPriceLimitX96: 0
})

Using the Smart Order Router (optimal path auto-routing)

import { AlphaRouter, SwapType } from '@uniswap/smart-order-router'
import { CurrencyAmount, TradeType, Percent } from '@uniswap/sdk-core'

const router = new AlphaRouter({ chainId: 1, provider })
const route = await router.route(
  CurrencyAmount.fromRawAmount(WETH_TOKEN, amountIn.toString()),
  USDC_TOKEN,
  TradeType.EXACT_INPUT,
  { slippageTolerance: new Percent(50, 10_000), deadline: Math.floor(Date.now()/1000) + 180, type: SwapType.SWAP_ROUTER_02, recipient }
)
// route.methodParameters.calldata — send directly

Adding Liquidity (Position Manager)

const NPM_ABI = ['function mint((address token0, address token1, uint24 fee, int24 tickLower, int24 tickUpper, uint256 amount0Desired, uint256 amount1Desired, uint256 amount0Min, uint256 amount1Min, address recipient, uint256 deadline)) external returns (uint256 tokenId, uint128 liquidity, uint256 amount0, uint256 amount1)']

// tick calculation: price → tick = Math.floor(Math.log(price) / Math.log(1.0001))

Common Pitfalls

• Setting amountOutMinimum to 0 exposes you to sandwich attacks — set it to at least 95% of the expected output
• Use staticCall for the Quoter — do not send it as a real transaction
• Always set a deadline to prevent transactions from waiting indefinitely in the mempool
• WETH address: 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2