Get spot prices on Uniswap

.env

INFURA_URL=<your_url>
ETHERSCAN_API_KEY=<your_api_key>

helpers.js

const axios = require('axios')

require('dotenv').config()
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY

exports.getAbi = async (address) => {
  const url = `https://api.etherscan.io/api?module=contract&action=getabi&address=${address}&apikey=${ETHERSCAN_API_KEY}`
  const res = await axios.get(url)
  const abi = JSON.parse(res.data.result)
  return abi
}

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
}

package.json

{
  "name": "uniswapbot",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@uniswap/v3-sdk": "^3.8.2",
    "axios": "^0.26.1",
    "dotenv": "^16.0.0",
    "ethers": "^5.6.2"
  }
}

uniswapBot.js

const { ethers } = require("ethers");
const { abi: IUniswapV3PoolABI } = require("@uniswap/v3-core/artifacts/contracts/interfaces/IUniswapV3Pool.sol/IUniswapV3Pool.json");
const { abi: QuoterABI } = require("@uniswap/v3-periphery/artifacts/contracts/lens/Quoter.sol/Quoter.json");

const { getAbi, getPoolImmutables } = require('./helpers')

require('dotenv').config()
const INFURA_URL = process.env.INFURA_URL
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY

const provider = new ethers.providers.JsonRpcProvider(INFURA_URL)

const poolAddress = '0xcbcdf9626bc03e24f779434178a73a0b4bad62ed'

const quoterAddress = "0xb27308f9F90D607463bb33eA1BeBb41C27CE5AB6"

const getPrice = async (inputAmount) => {
  const poolContract = new ethers.Contract(
    poolAddress,
    IUniswapV3PoolABI,
    provider
  )

  const tokenAddress0 = await poolContract.token0();
  const tokenAddress1 = await poolContract.token1();

  const tokenAbi0 = await getAbi(tokenAddress0)
  const tokenAbi1 = await getAbi(tokenAddress1)

  const tokenContract0 = new ethers.Contract(
    tokenAddress0,
    tokenAbi0,
    provider
  )
  const tokenContract1 = new ethers.Contract(
    tokenAddress1,
    tokenAbi1,
    provider
  )

  const tokenSymbol0 = await tokenContract0.symbol()
  const tokenSymbol1 = await tokenContract1.symbol()
  const tokenDecimals0 = await tokenContract0.decimals()
  const tokenDecimals1 = await tokenContract1.decimals()

  const quoterContract = new ethers.Contract(
    quoterAddress,
    QuoterABI,
    provider
  )

  const immutables = await getPoolImmutables(poolContract)

  const amountIn = ethers.utils.parseUnits(
    inputAmount.toString(),
    tokenDecimals0
  )

  const quotedAmountOut = await quoterContract.callStatic.quoteExactInputSingle(
    immutables.token0,
    immutables.token1,
    immutables.fee,
    amountIn,
    0
  )

  const amountOut = ethers.utils.formatUnits(quotedAmountOut, tokenDecimals1)

  console.log('=========')
  console.log(`${inputAmount} ${tokenSymbol0} can be swapped for ${amountOut} ${tokenSymbol1}`)
  console.log('=========')
}

getPrice(1)

I tried to use this example to get price of the pair that includes USDC (e.g. WBTC-USDC) on Mainnet and got an error. What could be a possible source of the problem? Perhaps that USDC has proxy contract?

The "is not a function" error you get when calling e.g. USDC based pool is caused by the fact that USDC is using a proxy which doesn't have either the symbol info, the decimals info or both. One solution is to hardcode those values when making the call.

I am not able to import Pool in node js
I used
const {Pool}= require('@uniswap/v3-sdk');

and module not found error is coming

@BlockmanCodes thanks for your script, works perfect. But how to invert for example USDT-SAITO to SAITO-USDT?

@Wantedslv You should be able to use the function quoteExactOutputSingle in the Quoter contract.

Getting this error: function selector was not recognized and there's no fallback function. Any suggestion here?