I'm executing the basic token contract found at https://ethereum.org/token:

contract tokenRecipient { function receiveApproval(address _from, uint256 _value, address _token, bytes _extraData); }

contract MyToken {
    /* Public variables of the token */
    string public standard = 'Token 0.1';
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;

    /* This creates an array with all balances */
    mapping (address => uint256) public balanceOf;
    mapping (address => mapping (address => uint256)) public allowance;

    /* This generates a public event on the blockchain that will notify clients */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /* Initializes contract with initial supply tokens to the creator of the contract */
    function MyToken(
        uint256 initialSupply,
        string tokenName,
        uint8 decimalUnits,
        string tokenSymbol
        ) {
        balanceOf[msg.sender] = initialSupply;              // Give the creator all initial tokens
        totalSupply = initialSupply;                        // Update total supply
        name = tokenName;                                   // Set the name for display purposes
        symbol = tokenSymbol;                               // Set the symbol for display purposes
        decimals = decimalUnits;                            // Amount of decimals for display purposes

    /* Send coins */
    function transfer(address _to, uint256 _value) {
        if (balanceOf[msg.sender] < _value) throw;           // Check if the sender has enough
        if (balanceOf[_to] + _value < balanceOf[_to]) throw; // Check for overflows
        balanceOf[msg.sender] -= _value;                     // Subtract from the sender
        balanceOf[_to] += _value;                            // Add the same to the recipient
        Transfer(msg.sender, _to, _value);                   // Notify anyone listening that this transfer took place

    /* Allow another contract to spend some tokens in your behalf */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData)
        returns (bool success) {
        allowance[msg.sender][_spender] = _value;
        tokenRecipient spender = tokenRecipient(_spender);
        spender.receiveApproval(msg.sender, _value, this, _extraData);
        return true;

    /* A contract attempts to get the coins */
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        if (balanceOf[_from] < _value) throw;                 // Check if the sender has enough
        if (balanceOf[_to] + _value < balanceOf[_to]) throw;  // Check for overflows
        if (_value > allowance[_from][msg.sender]) throw;   // Check allowance
        balanceOf[_from] -= _value;                          // Subtract from the sender
        balanceOf[_to] += _value;                            // Add the same to the recipient
        allowance[_from][msg.sender] -= _value;
        Transfer(_from, _to, _value);
        return true;

    /* This unnamed function is called whenever someone tries to send ether to it */
    function () {
        throw;     // Prevents accidental sending of ether

But when I see the log at testrpc or I look at web3.eth.getTransactionReceipt(txHash)I can't see any log or event.

Does anybody know what could I've doing wrong? Any known bug with web3 or testrpc in this topic?

  • Possible duplicate of contract event not firing in web3 node console
    – niksmac
    Jun 23, 2016 at 1:43
  • How much gas are you providing and what is gasUsed in the receipt? Have you tried increasing the gas and which function are you invoking?
    – eth
    Jun 23, 2016 at 4:05
  • i'm using 100.000 gas and I'm using less than the half Jun 23, 2016 at 6:30
  • @niksmac that's not a duplicate of my question, I'm watching the good way the events, also looking at testrpc logs and inscpecting the TokenReceipt, and nothing works. Jun 23, 2016 at 6:32
  • Please check if your account is unlocked. If your account is locked, the transaction is sent but you do not get a receipt. See ethereum.stackexchange.com/questions/4307/…. Jun 23, 2016 at 13:54

1 Answer 1


Is any ether being transferred? Is it going through? If so, try making sure the ABI's are correct. If that doesn't fix your problem try using this methodology for monitoring events:

var contract = web3.eth.contract(abi).at(addr);
var transfers = contract.Transfer( {}, {fromBlock: 0, toBlock: 'latest'})

//Watch Events
transfers.watch(function(error, result) {


Can you post your web3 transaction code?

  • This code is very old and gives me the error, "cannot call watch on undefined"
    – Jim
    Nov 1, 2021 at 19:53

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