.env

INFURA_URL_TESTNET=
WALLET_ADDRESS=
WALLET_SECRET=

abi.json

[
  {
    "inputs": [],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      }
    ],
    "name": "allowance",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "decimals",
    "outputs": [
      {
        "internalType": "uint8",
        "name": "",
        "type": "uint8"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "subtractedValue",
        "type": "uint256"
      }
    ],
    "name": "decreaseAllowance",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "addedValue",
        "type": "uint256"
      }
    ],
    "name": "increaseAllowance",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

helpers.js

exports.getPoolImmutables = async (poolContract) => {
  const [token0, token1, fee] = await Promise.all([
    poolContract.token0(),
    poolContract.token1(),
    poolContract.fee()
  ])

  const immutables = {
    token0: token0,
    token1: token1,
    fee: fee
  }
  return immutables
}

exports.getPoolState = async (poolContract) => {
  const slot = poolContract.slot0()

  const state = {
    sqrtPriceX96: slot[0]
  }

  return state
}

package.json

{
  "name": "uniswaptrader",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@uniswap/sdk-core": "^3.0.1",
    "@uniswap/v3-sdk": "^3.8.2",
    "dotenv": "^16.0.0",
    "ethers": "^5.6.4"
  }
}

uniswapTrader.js

const { ethers } = require('ethers')
const { abi: IUniswapV3PoolABI } = require('@uniswap/v3-core/artifacts/contracts/interfaces/IUniswapV3Pool.sol/IUniswapV3Pool.json')
const { abi: SwapRouterABI} = require('@uniswap/v3-periphery/artifacts/contracts/interfaces/ISwapRouter.sol/ISwapRouter.json')
const { getPoolImmutables, getPoolState } = require('./helpers')
const ERC20ABI = require('./abi.json')

require('dotenv').config()
const INFURA_URL_TESTNET = process.env.INFURA_URL_TESTNET
const WALLET_ADDRESS = process.env.WALLET_ADDRESS
const WALLET_SECRET = process.env.WALLET_SECRET

const provider = new ethers.providers.JsonRpcProvider(INFURA_URL_TESTNET) // Ropsten
const poolAddress = "0x4D7C363DED4B3b4e1F954494d2Bc3955e49699cC" // UNI/WETH
const swapRouterAddress = '0xE592427A0AEce92De3Edee1F18E0157C05861564'

const name0 = 'Wrapped Ether'
const symbol0 = 'WETH'
const decimals0 = 18
const address0 = '0xc778417e063141139fce010982780140aa0cd5ab'

const name1 = 'Uniswap Token'
const symbol1 = 'UNI'
const decimals1 = 18
const address1 = '0x1f9840a85d5af5bf1d1762f925bdaddc4201f984'

async function main() {
  const poolContract = new ethers.Contract(
    poolAddress,
    IUniswapV3PoolABI,
    provider
  )

  const immutables = await getPoolImmutables(poolContract)
  const state = await getPoolState(poolContract)

  const wallet = new ethers.Wallet(WALLET_SECRET)
  const connectedWallet = wallet.connect(provider)

  const swapRouterContract = new ethers.Contract(
    swapRouterAddress,
    SwapRouterABI,
    provider
  )

  const inputAmount = 0.001
  // .001 => 1 000 000 000 000 000
  const amountIn = ethers.utils.parseUnits(
    inputAmount.toString(),
    decimals0
  )

  const approvalAmount = (amountIn * 100000).toString()
  const tokenContract0 = new ethers.Contract(
    address0,
    ERC20ABI,
    provider
  )
  const approvalResponse = await tokenContract0.connect(connectedWallet).approve(
    swapRouterAddress,
    approvalAmount
  )

  const params = {
    tokenIn: immutables.token1,
    tokenOut: immutables.token0,
    fee: immutables.fee,
    recipient: WALLET_ADDRESS,
    deadline: Math.floor(Date.now() / 1000) + (60 * 10),
    amountIn: amountIn,
    amountOutMinimum: 0,
    sqrtPriceLimitX96: 0,
  }

  const transaction = swapRouterContract.connect(connectedWallet).exactInputSingle(
    params,
    {
      gasLimit: ethers.utils.hexlify(1000000)
    }
  ).then(transaction => {
    console.log(transaction)
  })
}

main()