Retrive the price of any bsc token from it's address without using external service like poocoin/dextools

tokenPriceApi.js

let pancakeSwapAbi =  [
{"inputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"}],"name":"getAmountsOut","outputs":[{"internalType":"uint256[]","name":"amounts","type":"uint256[]"}],"stateMutability":"view","type":"function"},
];
let tokenAbi = [
{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},
];
const Web3 = require('web3');

/*
Required Node.js

-- Web3 Token Charting --

Checkout my repo about building a clone of poocoin/dextools on bsc/pancakeswap and on any other similar chain/dex

https://github.com/Linch1/Web3TokenCharting


-- Usage --

1. Make a directory on your pc
2. Open a terminal 
3. go inside the created directory
4. run : npm init
5. run : npm i --save web3

6. Create a file: tokenPrice.js
7. Copy this text inside that file
8. run: node tokenPrice.js

*/


let pancakeSwapContract = "0x10ED43C718714eb63d5aA57B78B54704E256024E".toLowerCase();
const web3 = new Web3("https://bsc-dataseed1.binance.org");
async function calcSell( tokensToSell, tokenAddres){
    const web3 = new Web3("https://bsc-dataseed1.binance.org");
    const BNBTokenAddress = "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c" //BNB

    let tokenRouter = await new web3.eth.Contract( tokenAbi, tokenAddres );
    let tokenDecimals = await tokenRouter.methods.decimals().call();
    
    tokensToSell = setDecimals(tokensToSell, tokenDecimals);
    let amountOut;
    try {
        let router = await new web3.eth.Contract( pancakeSwapAbi, pancakeSwapContract );
        amountOut = await router.methods.getAmountsOut(tokensToSell, [tokenAddres ,BNBTokenAddress]).call();
        amountOut =  web3.utils.fromWei(amountOut[1]);
    } catch (error) {}
    
    if(!amountOut) return 0;
    return amountOut;
}
async function calcBNBPrice(){
    const web3 = new Web3("https://bsc-dataseed1.binance.org");
    const BNBTokenAddress = "0xbb4CdB9CBd36B01bD1cBaEBF2De08d9173bc095c" //BNB
    const USDTokenAddress  = "0x55d398326f99059fF775485246999027B3197955" //USDT
    let bnbToSell = web3.utils.toWei("1", "ether") ;
    let amountOut;
    try {
        let router = await new web3.eth.Contract( pancakeSwapAbi, pancakeSwapContract );
        amountOut = await router.methods.getAmountsOut(bnbToSell, [BNBTokenAddress ,USDTokenAddress]).call();
        amountOut =  web3.utils.fromWei(amountOut[1]);
    } catch (error) {}
    if(!amountOut) return 0;
    return amountOut;
}
function setDecimals( number, decimals ){
    number = number.toString();
    let numberAbs = number.split('.')[0]
    let numberDecimals = number.split('.')[1] ? number.split('.')[1] : '';
    while( numberDecimals.length < decimals ){
        numberDecimals += "0";
    }
    return numberAbs + numberDecimals;
}
/*

How it works?
This script simply comunicates with the smart contract deployed by pancakeswap and calls the main
function that was build to retrive the token prices
*/
(async () => {
    const tokenAddres = '0xa49e44976c236beb51a1f818d49b9b9759ed97b1'; // change this with the token addres that you want to know the 
    let bnbPrice = await calcBNBPrice() // query pancakeswap to get the price of BNB in USDT
    console.log(`CURRENT BNB PRICE: ${bnbPrice}`);
    // Them amount of tokens to sell. adjust this value based on you need, you can encounter errors with high supply tokens when this value is 1.
    let tokens_to_sell = 1; 
    let priceInBnb = await calcSell(tokens_to_sell, tokenAddres)/tokens_to_sell; // calculate TOKEN price in BNB
    console.log( 'SHIT_TOKEN VALUE IN BNB : ' + priceInBnb + ' | Just convert it to USD ' );
    console.log(`SHIT_TOKEN VALUE IN USD: ${priceInBnb*bnbPrice}`); // convert the token price from BNB to USD based on the retrived BNB value
})();

If you want to get the same in Python.
https://github.com/Goatghosts/token-price-api-py

How can I invert the pair? For example default is sell Token1 for BNB, but I want to sell BNB for Token1 (to see price for buying Token1). Because price when I selling Token1 or buying Token1 is different on PCS. Thanks.

@Wantedslv just edit the path from [token1, token2] to [token2, token1]

@Wantedslv just edit the path from [token1, token2] to [token2, token1]

@KingMaxine Don't quite understand which line of code do you mean?
I'd tried to replace [token1, token2] to [token2, token1] in the line 49, but it doesn't work.

I need help. I'm trying to figure out how to identify any liquidity that has just been added to the pancake pool. By checking the pair factory, I can only search for newly created pairs, previous pairs cannot be verified. Thanks for your help

I need help. I'm trying to figure out how to identify any liquidity that has just been added to the pancake pool. By checking the pair factory, I can only search for newly created pairs, previous pairs cannot be verified. Thanks for your help

you can use getPair function on 0xcA143Ce32Fe78f1f7019d7d551a6402fC5350c73 tokenaddress / wbnb

I need help. I'm trying to figure out how to identify any liquidity that has just been added to the pancake pool. By checking the pair factory, I can only search for newly created pairs, previous pairs cannot be verified. Thanks for your help

To identify whenever someone add liquidity to a pair you can make a subscription to the Mint event,
it is emitted whenever someone adds liquidity to pancakeswap

Clever solution. Thank you !

(async () => {
    const Token     = '0x0e09fabb73bd3ade0a17ecc321fd13a19e81ce82';
    const abi       = [{"inputs":[{"internalType":"uint256","name":"amountIn","type":"uint256"},{"internalType":"address[]","name":"path","type":"address[]"}],"name":"getAmountsOut","outputs":[{"internalType":"uint256[]","name":"amounts","type":"uint256[]"}],"stateMutability":"view","type":"function"},]
    const web3      = new Web3(Web3.givenProvider);
    const contract  = new web3.eth.Contract(abi, '0x10ed43c718714eb63d5aa57b78b54704e256024e');
    const result    = await  contract.methods.getAmountsOut((10 ** 18) + '', [Token, '0xe9e7cea3dedca5984780bafc599bd69add087d56']).call();
    const price     = result[1] / (10 ** 18);
    console.log('$' + price.toFixed(2) );
})();

This is awesome man thanks for this.

I've been working on router contracts for a while now and I have no issues calculating prices from an LP, but there's still 1 thing that i haven't figure it out yet, which is how does the dex figure out the best route for a swap pair to get the best price(minimum slippage)? Example:

1. Swap 100 FROYO to BUSD, Route: FROYO>CAKE>BUSD.
2. Swap 10000 FROYO to BUSD, Route: FROYO>BNB>BUSD.

I still haven't work this out this algorithm yet, anyone has any experience or advice on this? I would appreciate any help or ideas!

Thank You!

I would like to ask your help to solve my problem. It is the script can't get the price of some tokens which their prices are very small. For example.
0x12F9e38F9e09D9dD84DC39A1f11d236bB9d9c27f
0x3ECd448a623d82E3dAecbeA8CD4Ba1310457dA1b
As I know so far, it seems the decimals of those tokens in bsc scan are smaller than the decimals of actual prices.
If possile please teach me how to update the script to be able get their prices
Thank you very much.

I will create a dart package for flutter apps from this code, thanks!