Hi

I'm using your code for 1 month but today it's not working and I don't know why. Whenever I try to buy with code transactions fail with 'INSUFFICIENT_INPUT_AMOUNT'. Could you look at this problem? Thanks.

Hi @religion-counter, I am using function "swapExactTokensForETHSupportingFeeOnTransferTokens" to sell token following your example: https://github.com/religion-counter/onlyone/blob/main/helper-scripts/sell-onlyone-pancakeswap.js#L76. --> I found out 2 issues:

1. Some token can't swap: example: 0x3e900195b93423b8e7bddd63d1d51c02fd18ccdf. I have changed using swapExactTokensForETH replace swapExactTokensForETHSupportingFeeOnTransferTokens, sell success.
2. I have read the document and found out that: using swapExactTokensForETH better "Identical to swapExactTokensForETH, but succeeds for tokens that take a fee on transfer." --> Please give me your opinion about the pros and cons of functions:

• swapExactTokensForETHSupportingFeeOnTransferTokens
• swapExactTokensForETH

Hi @religion-counter, I have a question about the source code in "sell-onlyone-pancakeswap.js" file:

What approves the transaction when sell the token? Is it necessary or not? I have commented code about Approve ONLYONE spend from line 50 - 67. I have still sell the token. Can you explain it , please? https://github.com/religion-counter/onlyone/blob/c402ad334bdcc38827f42a5de707e0dea7bd8bd7/helper-scripts/sell-onlyone-pancakeswap.js#L50

Hi @religion-counter , I have built and buy the success token following: https://github.com/religion-counter/onlyone/blob/main/helper-scripts/buy-onlyone-pancakeswap.js But, I wanna raise slippage. You know, many tokens have slippage very high. Please give me your opinion. Thanks.

Hi @religion-counter, I have an issue that needs suggestions from you: How to get Amount a token in my wallet metamask (BSC)? Please give me your opinion. Thanks

Hi, first of all thanks a lot for this content, it's hard to find this kind of code to let us know how things work under the hood.
I'm trying to buy a token (RUSD) with BUSD. The fact is i'm always getting that i have not enough funds on my wallet, even if i have enough BNB (0.5) to pay the transaction fee.

I'm using your code, just changed a few things for my needs:

var fs = require('fs')
var Tx = require('ethereumjs-tx').Transaction;
var Web3 = require('web3')
var Common = require('ethereumjs-common').default;

var web3 = new Web3(new Web3.providers.HttpProvider('https://bsc-dataseed.binance.org/'))
var BSC_FORK = Common.forCustomChain(
    'mainnet',
    {
        name: 'Binance Smart Chain Mainnet',
        networkId: 56,
        chainId: 56,
        url: 'https://bsc-dataseed.binance.org/'
    },
    'istanbul',
);

// Amount to buy
const execSync = require('child_process').execSync;
const originalAmountToBuyWith = execSync('node getTokensBalance.js busd', { encoding: 'utf-8' }).replace(/\s+/g, ' ').trim();

var busdAmount = web3.utils.toWei(originalAmountToBuyWith, 'ether');

var config = JSON.parse(fs.readFileSync('config.json', 'utf-8'));

console.log(`Buying RUSD for ${originalAmountToBuyWith} BUSD from pancakeswap for address ${config.walletAddress}`);

var res = buyRUSD(config.walletAddress, busdAmount);
console.log(res);

async function buyRUSD(walletAddress, amount) {

    var amountToBuyWith = web3.utils.toHex(amount);
    var privateKey = Buffer.from(config.privateKey, 'hex')  ;

    var amountOutMin = '100' + Math.random().toString().slice(2,6);

    var routerAbi = JSON.parse(fs.readFileSync('pancake-router-abi.json', 'utf-8'));
    var contract = new web3.eth.Contract(routerAbi, config.pancakeSwapRouterAddress, {from: walletAddress});
    var data = contract.methods.swapExactETHForTokens(
        web3.utils.toHex(amountOutMin),
        [config.busdAddress,
         config.rusdAddress],
        walletAddress,
        web3.utils.toHex(Math.round(Date.now()/1000)+60*20),
    );

    var count = await web3.eth.getTransactionCount(walletAddress);

    var rawTransaction = {
        "from":walletAddress,
        "gasPrice": web3.utils.toHex(web3.utils.toWei('5', 'gwei')),
        "gasLimit": 100000,
        "to":config.pancakeSwapRouterAddress,
        "value":web3.utils.toHex(amountToBuyWith),
        "data":data.encodeABI(),
        "nonce":web3.utils.toHex(count)
    };

    var transaction = new Tx(rawTransaction, { 'common': BSC_FORK });
    transaction.sign(privateKey);

    var result = await web3.eth.sendSignedTransaction('0x' + transaction.serialize().toString('hex'));
    return result;
}

I always get (node:327974) UnhandledPromiseRejectionWarning: Error: Returned error: insufficient funds for gas * price + value. I'm using my metamask wallet, i'm sure the wallet address is good, also the privatekey associated.

Another point, how are you sure you won't spend too much transaction fees if there is some congestion ? gasLimit i suppose.

Thanks again mate if you have any idea! Gabriel.

When I buy ONLYONE I get (node: 75260) UnhandledPromiseRejectionWarning: Error: Returned error: transaction underpriced, what could be wrong? The code is exactly like yours.

https://github.com/religion-counter/onlyone/blob/main/helper-scripts/buy-onlyone-pancakeswap.js

Hi bro,

I fixed all my mistakes for buying a token but, can't sell 🤒

Could you help ?

Failed Transaction

// Sells ONLYONE for BNB from pancakeswap for address ${targetAccounts[targetIndex].address}

var fs = require('fs')
var Tx = require('ethereumjs-tx').Transaction;
var Web3 = require('web3')
var Common = require('ethereumjs-common').default;

var web3 = new Web3(new Web3.providers.HttpProvider('https://bsc-dataseed.binance.org/'))
var BSC_FORK = Common.forCustomChain(
    'mainnet',
    {
        name: 'Binance Smart Chain Mainnet',
        networkId: 56,
        chainId: 56,
        url: 'https://bsc-dataseed.binance.org/'
    },
    'istanbul',
);


let rawData = fs.readFileSync('data.json');
let progData = JSON.parse(rawData);

sellMulty();

async function sellMulty() {
    var onyloneAmount = 1;
    var res = sellOnlyone(progData.mainAccount, onyloneAmount*1e18)
    .catch(e => {
        console.error("Error in sell:", e);
        process.exit(1);
    });
    console.log(res);
    
}

async function sellOnlyone(targetAccount, amount) {

    var amountToSell = web3.utils.toHex(amount);
    var privateKeyBuffer =  progData.privateKey;
    var privateKey = Buffer.from(privateKeyBuffer,'hex');
    var abiArray = JSON.parse(JSON.parse(fs.readFileSync('onlyone-abi.json','utf-8')));

    var tokenAddress = '0x370AbbD30774E52C47C596807a288cec48f42319'; // CAKEWHALE contract address
    var WBNBAddress = '0xbb4cdb9cbd36b01bd1cbaebf2de08d9173bc095c'; // WBNB token address
    var pancakeSwapRouterAddress = '0x10ed43c718714eb63d5aa57b78b54704e256024e';

    // Approve ONLYONE spend
    var onlyoneContract = new web3.eth.Contract(abiArray, tokenAddress, {from: targetAccount});
    var approveOnlyoneSpendData = onlyoneContract.methods.approve(pancakeSwapRouterAddress, web3.utils.toWei('1', 'ether'));
    var count = await web3.eth.getTransactionCount(targetAccount);
    var rawTransactionApprove = {
        "from":targetAccount,
        "gasPrice":web3.utils.toHex(5000000000),
        "gasLimit":web3.utils.toHex(210000),
        "to":tokenAddress,
        "value":"0x0",
        "data":approveOnlyoneSpendData.encodeABI(),
        "nonce":web3.utils.toHex(count)
    };
    var transactionApprove = new Tx(rawTransactionApprove, {'common':BSC_FORK});
    transactionApprove.sign(privateKey)

    var resultApprove = await web3.eth.sendSignedTransaction('0x' + transactionApprove.serialize().toString('hex'));
    console.log("Approved" + resultApprove);

    // var onlyOneWbnbCakePairAddress = '0xd22fa770dad9520924217b51bf7433c4a26067c2';
    // var pairAbi = JSON.parse(fs.readFileSync('cake-pair-onlyone-bnb-abi.json', 'utf-8'));
    // var pairContract = new web3.eth.Contract(pairAbi, onlyOneWbnbCakePairAddress/*, {from: targetAccount.address}*/);
    var amountOutMin = web3.utils.toHex(1); // 540BNB is the price of one onlyone

    var routerAbi = JSON.parse(fs.readFileSync('pancake-router-abi.json', 'utf-8'));
    var contract = new web3.eth.Contract(routerAbi, pancakeSwapRouterAddress, {from: targetAccount});
    var data = contract.methods.swapExactTokensForETHSupportingFeeOnTransferTokens(
        amountToSell,
        amountOutMin,
        [tokenAddress,
        //  '0xe9e7cea3dedca5984780bafc599bd69add087d56' /* BUSD address */, // Add this if you want to go through the onlyone-busd pair
         WBNBAddress],
        targetAccount,
        web3.utils.toHex(Math.round(Date.now()/1000)+60*20),
    );

    count = await web3.eth.getTransactionCount(targetAccount);
    var rawTransaction = {
        "from":targetAccount,
        "gasPrice":web3.utils.toHex(5000000000),
        "gasLimit":web3.utils.toHex(460000),
        "to":pancakeSwapRouterAddress,
        "value":web3.utils.toHex(0),
        "data":data.encodeABI(),
        "nonce":web3.utils.toHex(count)
    };

    var transaction = new Tx(rawTransaction, { 'common': BSC_FORK });
    transaction.sign(privateKey);

    var result = await web3.eth.sendSignedTransaction('0x' + transaction.serialize().toString('hex'));
    console.log(result)
    return result;
}

function sleep(ms) {
    return new Promise((resolve) => {
        setTimeout(resolve, ms);
    });
} 

Hello hope you are good ?

i run npm install

i creat a files .json like this : [{"address":"0x551c1F831533/////55FB6fa3ef86","privateKey":"a7fda8be82590279/////////412a96e8c85"}]

i run node buy-onlyone-pancakeswap.js and get this error : console.log(Buying ONLYONE for ${originalAmountToBuyWith} BNB from pancakeswap for address ${targetAccount.address}); ^ TypeError: Cannot read properties of undefined (reading 'address')

helloo, I hope you are all well. first thank you for the example, I am learning a ton from reading and adapting the code.

I cannot however get a basic buy to work.

Error: Private key must be 32 bytes in length. (tx type=0 hash=not available (unsigned) nonce=12 value=125141000000000 signed=false hf=istanbul gasPrice=5000000000)

I get the error above. Do you think this is an issue with my address and private key? I have copied the adress and private key from my bsc wallet, I even tried changing the private key to hex.

any help would be appreciated thanks (:

Hi, hope you're well. It's quite hard to find relevant information when we are developing our own code so i try here hoping it may help other people.

I'm looking about getting the best price (meaning having the best 'path') before calling my swap function (ex swapExactTokensForXXX). So here the third parameter is the raw path provided but if you're using pancakeswap for ex, you'll see that before swapping it will be able to find for you the best route / path in order to provide you the best price. For ex instead of stupidly working with the pool token1/token2, it will propose a best price with the route token1/tokenX/token2, using different liquidity pools.

So my question is; do you have any clue about how to find the best route when dealing with these contracts ?

Thanks a lot, Cheers.

[edit] Interesting links:
https://github.com/uniswap-integration/simple-uniswap-sdk#uniswap-pair-factory

Hey, I tried your examples for buying tokens on PancakeSwap. Everything works fine. Now Im trying to sell tokens and I cant get it to work. Could you maybe make an example for that too, or give me some tips? Thanks!