[Ethereum] Web3 sending custom tokens by using the transfer function. Need to set the from account

erc-20web3js

Looking to code WEB3 to be able to send custom tokens out programmatically.

However, I am not sure where to specify the user account that actually sends the token.

This is the code I have thus far. I

var custom_token_address = req.params.customtoken;
  var abi = loadABI();
  var MyContract = web3.eth.contract(abi);
  var myContractInstance = MyContract.at('0x416DFae2FED9B7a282E8beaC750210A7d952204A');

web3.eth.contract(abi).at(custom_token_address).transfer('0x61E28c6d1e5159E2415644FBBE5E0D40542e4C8c', 10000);

Where is is that I set the from account in all of this?

Thank you

Best Answer

[Note: the below is with web3.js 0.20 (the syntax changes for 1.0.0)]

You can either set the default from account for all transactions:

web3.eth.defaultAccount = '0x........';

Or you can specify a transaction object on a case-by-case basis as the last parameter in your method:

web3.eth.contract(abi).at(custom_token_address).transfer('0x61E28c6d1e5159E2415644FBBE5E0D40542e4C8c', 10000, {from: '0x........'});

Related Solutions

[Ethereum] How to send ERC20 token using Web3 API

I'm using web3.js version: 0.20.1 in node.js express application. I'm running Parity in Virtualbox Ubuntu machine.

The correct code looks like following:

var count = web3.eth.getTransactionCount("0x26...");
var abiArray = JSON.parse(fs.readFileSync('mycoin.json', 'utf-8'));
var contractAddress = "0x8...";
var contract = web3.eth.contract(abiArray).at(contractAddress);
var rawTransaction = {
    "from": "0x26...",
    "nonce": web3.toHex(count),
    "gasPrice": "0x04e3b29200",
    "gasLimit": "0x7458",
    "to": contractAddress,
    "value": "0x0",
    "data": contract.transfer.getData("0xCb...", 10, {from: "0x26..."}),
    "chainId": 0x03
};

var privKey = new Buffer('fc3...', 'hex');
var tx = new Tx(rawTransaction);

tx.sign(privKey);
var serializedTx = tx.serialize();

web3.eth.sendRawTransaction('0x' + serializedTx.toString('hex'), function(err, hash) {
    if (!err)
        console.log(hash);
    else
        console.log(err);
});

[Ethereum] Transfer ERC20 Token using Ropsten Infura with Web3

The problem is that you are sending a non-zero value (1gwei in your example). If you want to transfer tokens then you have to set value to zero.

var rawTransaction = {
  "value": 0,
   ...
};

The reason is because for security functions that receive ether must have the payable modifier. Your transfer function doesn't have that modifier, and will reject any transaction with a non zero amount of ether.

function transfer(address _to, uint256 _value) public {
    _transfer(msg.sender, _to, _value);
}

Best Answer

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[Ethereum] How to send ERC20 token using Web3 API

[Ethereum] Transfer ERC20 Token using Ropsten Infura with Web3

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