web3 js coder

Transfer ERC20 tokens in nodejs

After the previous transfer of eth, this time we will continue to see how to transfer ERC20 tokens.

Install dependencies and initialize web3#

I won't go into detail here. If you don't know how to initialize web3, you can refer to one of my previous articles.

Initialize the contract object Contract#

Last time we created a start method. This time we will create a startContract method inside it, and replace the code below with the execution of the startContract method.

const startContract = async () => {
    let currentAddress = '0xe208D2fB37df02061B78848B83F02b4AD33540e4'
    let toAddress = '0x3EcAa09DD6B8828607bba4B1d7055Ea1143f8B94'
  // This time we still choose uni on the goerli test chain for the token
    const uniContractAddress = '0x1f9840a85d5af5bf1d1762f925bdaddc4201f984'    // uni erc20 token contract address

    const uniswapAbi = []	// uni's abi information, you can find it yourself, or you can check my web3 learning notes for specific search methods
    const uniToken = new web3.eth.Contract(uniswapAbi, uniContractAddress)

This way we have the contract object Contract.

Initialize parameters#

Let's prepare some parameters needed for the transaction.

const privateKey = Buffer.from('Your wallet private key', 'hex')
// Before setting the amount, we need to get the precision of the token currency. Here the decimals value is 18, which means 18 digits.
const decimals = await uniToken.methods.decimals().call()

// amount = transfer amount * decimals, here we transfer 1 uni token
const amount = web3.utils.toHex(1 * Math.pow(10, decimals))

const count = await web3.eth.getTransactionCount(currentAddress)

const txParams = {
  from: currentAddress,
  to: uniContractAddress,
  gasPrice: web3.utils.toHex(web3.utils.toWei('10', 'gwei')),
  gasLimit: web3.utils.toHex(210000),
  value: web3.utils.toHex(0),
  data: uniToken.methods.transfer(toAddress, amount).encodeABI(),
  nonce: web3.utils.toHex(count)

const tx = new EthereumTx(txParams, {
  chain: 'goerli'


Now we have the required parameters and have signed the key.

The above ethereumjs-tx signature scheme uses ethereumjs-common by default, which has:

  • mainnet
  • ropsten
  • rinkeby
  • kovan
  • goerli (final configuration since v1.1.0)
    You can directly sign for these chains. For other chains, you need to require ethereumjs-common yourself.
const  Common = require('ethereumjs-common').default
const blockchain = Common.forCustomChain(
    'mainnet', {
        name: 'Fantom Opera',
        networkId: 250,
        chainId: 250

const tx = new EthereumTx(txParams, {
    common: blockchain


Send transaction#

web3.eth.sendSignedTransaction('0x' + tx.serialize().toString('hex'))
  .on('transactionHash', console.log)
  .catch(err => {

This way we have already sent the token.

Ownership of this post data is guaranteed by blockchain and smart contracts to the creator alone.