I looked everywhere for people with similar problems, but I couldn't find anything.

I am confused why I keep getting this error (yes, I know others have had this error too, but not for the same reason as I):

>Error: invalid bytes32 value (arg="_orgName", coderType="bytes32", value="0x7b22436f6e74656e742d54797065223a226170706c69636174696f6e2f782d7777772d666f726d2d75726c656e636f646564222c224e616d65223a22546573742075736572227d")

1) The information the node server is passing to the contract is a payload from a webpage.

2) Essentially here is what is happening:

  • Node takes form payload which is a json object and converts it into hex

  • Send hex to the contract with the 3 fields orgName,helloId,fctChain.

I know I am passing in the right data, but I keep getting an error return. When i did a typeof convertToHex i got a string.

Any guidance is helpful.

Thank you,

Here's what my code looks like:

function sendToContract(req, res, next) {

  let convertToHex = web3.utils.toHex(JSON.stringify(req.body));

  ACF.methods.registerNewAsset(convertToHex, convertToHex, fctAddress).send()
    .then(results => {
    .catch(err => {
      // console.log(err)

Here's what the contract looks like:

function registerNewAsset(bytes32 _orgName, uint _hellId, bytes32 _fctChain) external onlyOwner {

        NewAsset storage asset = hercIdToAsset[_hercId];

        asset.orgName = _orgName;
        asset.helloId = _helloId;
        asset.fctChain = _fctChain;



My goal was to implement the send transaction based on this documentation: https://web3js.readthedocs.io/en/1.0/web3-eth-contract.html#methods-mymethod-send

I'm using web3js + node + solidity.

  • I suggest that you console.log(JSON.stringify(req.body)) and see what exactly it is that you're trying to convert to hex. Nov 29, 2018 at 9:12
  • @goodvibration i was converting the entire form payload into hex. turns out i only needed 3 portions of it, so now i am reassigning the variables to specific portion of the payload and converting that into hex and then pushing it out to the smart contract, however, i am not sure if that will work. Nov 29, 2018 at 21:11

1 Answer 1


IMO, there are ample things wrong in code.

let convertToHex = web3.utils.toHex(JSON.stringify(req.body));

In this line, you are trying to convert complete request body in hex not a property of it, which doesn't seem a desired behaviour.

function registerNewAsset(bytes32 _orgName, uint _hellId, bytes32 _fctChain)

Apart from this, in this line, you second parameter is uint but you are sending same hex (i.e. convertToHex) for _helloId.

Also, from the name of third parameter(i.e. fctAddress), it seems that you are passing an address to bytes32 type variable _fctChain.

I think, rectifying each of them will get it working.


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