Transaction was not mined within 50 blocks

const axios = require('axios');                     //used for getting api data, install with "yarn add axios"
const Web3 = require('web3');                       //used for web3 functions, install with "yarn add web3"
const Common = require('ethereumjs-common').default;//used for creating custom chains, install with "yarn add '@ethereumjs/common@v2.2.0'"
let Tx = require('ethereumjs-tx').Transaction;

let ETHprovider = new Web3.providers.WebsocketProvider('wss://')
let web3 = new Web3(ETHprovider);
let privateKey = Buffer.from('PRIVATE_KEY', 'hex');
const ADDRESS = 'ADDRESS';//your address
let callURL = '' +
    'toTokenAddress=0x27f8d03b3a2196956ed754badc28d73be8830a6e&' +
    'amount=10000000000000000000&fromAddress=' +
let approveURL = '';

const ethereumMainnet = { 'chain': 'mainnet' }
async function driver() {
    globalData = await approveApiCaller(approveURL, 10000000000000000000, "0x8f3cf7ad23cd3cadbd9735aff958023239c6a063", "0xfe");
    console.log('Global Data done')
    transaction = signTx(globalData);               //sign the transaction with 
    console.log(transaction);                       //print the serialized transaction
    console.log('Sign global data')
    sendTransaction(transaction);                   //send the transaction
    console.log('Send Transaction')
    globalData = await apiCaller(callURL, '0xff');  //call the api to get the data, and wait until it returns
    console.log(globalData["tx"]);                  //log the data
    transaction = signTx(globalData["tx"]);         //sign the transaction
    console.log('send transaction');
    sendTransaction(transaction);                   //send the transaction
    console.log("transaction success");

 * Sends a transaction based on serialized data
 * @param {the serialized transaction you want to send} tx 
function sendTransaction(tx) {
    let temp = '0x' + tx.toString('hex');           //make the transaction into a hexadecimal string
    .on('transactionHash', async function(hash){
        const status = await waitTransaction(hash);
    .on('receipt', function(receipt){
    .on('confirmation', function(confirmationNumber, receipt){ 
    .on('error', function(error, receipt) {
    }); // If a out of gas error, the second parameter is the receipt.
 * Will sign a transaction with a private key based on the transaction data provided
 * @param {the transaction you'd like signed} tx
 * @returns serialized transaction
function signTx(tx) {
    let temp = new Tx(tx, ethereumMainnet);
    //let temp = new Tx(tx, { common: ethereumMainnet });
    return temp.serialize();
 * This will call the api to get an approve transaction, some tokens need to be approved to 0 before increasing again later
 * @param {the url used to access the } url 
 * @param {the number of tokens that are requested to be unlocked, if "null" infinite will be unlocked } value 
 * @param {the token address of what tokens needs to be unlocked} tokenAddress
 * @param {the nonce of the transaction} nonce
 * @returns approve transaction
async function approveApiCaller(url, value, tokenAddress, nonce) {
    url += (value > -1 || value != null ? "?amount=" + value + "&" : "") //tack on the value if it's greater than -1
        + "tokenAddress=" + tokenAddress             //complete the called URL
    let temp = await axios.get(url);                //wait for the request to be complete

    temp =;                               //we only want the data object from the api call
    //we need to convert the gas price to hex
    let gasPrice = parseInt(temp["gasPrice"]);
    gasPrice = '0x' + gasPrice.toString(16);        //convert to hexadecimal string
    temp["value"] = "0x" + temp["value"];           //convert value to hecadecimal
    temp["gasPrice"] = gasPrice;                    //change the gas price in the tx object
    temp["gas"] = "0xc350";                         //gas limit of 50,000, may need to be higher for certain tokens
    temp["from"] = ADDRESS;
    temp["nonce"] = nonce;

    return temp;

 * Will call the api and return the data needed
 * @param {the url of what api call you want} url 
 * @param {the nonce of the transaction, the user must keep track of this} nonce
 * @returns swap transaction
async function apiCaller(url, nonce) {
    let temp = await axios.get(url);                //get the api call
    temp =;                               //we only want the data object from the api call
    //we need to convert the gasPrice to hex
    let gasPrice = parseInt(temp.tx["gasPrice"]);   //get the gasPrice from the tx
    gasPrice = '0x' + gasPrice.toString(16);        //add a leading 0x after converting from decimal to hexadecimal
    temp.tx["gasPrice"] = gasPrice;                 //set the value of gasPrice in the transaction object
    //we also need value in the form of hex
    let value = parseInt(temp.tx["value"]);			    //get the value from the transaction
    value = '0x' + value.toString(16);				      //add a leading 0x after converting from decimal to hexadecimal
    temp.tx["value"] = value;						            //set the value of value in the transaction object
    temp.tx["nonce"] = nonce;  
    console.log(temp);    //it's the users responsibility to keep track of the nonce
    return temp;                                    //return the data

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

async function waitTransaction(txHash) {
    let tx = null;
    while (tx == null) {
        tx = await web3.eth.getTransactionReceipt(txHash);
        await sleep(2000);
    console.log("Transaction " + txHash + " was mined.");
    return (tx.status);

Sorry guys, I needed some help badly. With the provided code, I am getting Transaction was not mined within 50 blocks, please make sure your transaction was properly sent. Be aware that it might still be mined! Sometime I get transaction underpriced. Can someone help me on this issue?

Hi @owsome888, and welcome to the Infura community! From the error message, it sounds like you may need to try increasing your gas price - have you tried that already?

Thank you Leiya for your very kind word.
I am using 1Inch official gas price, may I know what’s the best way to set the gas price?

I tried to increase the gas price 10 fold and having the same problem. My transaction hash is 0xe46966e4dc76f539ae0255c6aa617aca0901e53da1f5028e5f9b1f4a4166978d

1 Like

Thanks for providing the transaction hash!

It’s interesting - in our system, it says that you tried sending this 5 different times - the first and second tries, your transaction was underpriced, but the third, fourth, and fifth times, it looks like it went through with the following result: {“jsonrpc”:“2.0”,“id”:2,“result”:“0xe46966e4dc76f539ae0255c6aa617aca0901e53da1f5028e5f9b1f4a4166978d”}