[Ethereum] Signing a message to sell NFT/token – what happens if you transfer the NFT later

dapp-developmentnftsignature

If you sign a message with intent to list an NFT/token for sale – how does that work if you transfer the item later?

For example on an NFT marketplace – you list your NFT for sale by signing a message. I'm assuming that signed message is a signed transaction to transfer the NFT to a contract that acts as a medium of exchange between buyer and seller.

But what if I sign that message – then transfer my NFT?

List NFT for sale
Site asks for Approval of NFT to be confirmed –
tx sent
Site asks for signature with listing details (price, etc)

I now exit site and send the NFT to my friend.
4. Someone fills that
listing for the NFT – but my NFT is gone
– how is the order filled?

Specifically I'm looking at a site like rarible – where that is the flow – they only get approval and thats it.

But I don't get how it works if you transfer that NFT?

Best Answer

The Ethereum transactions have a parameter called "nonce" representing the number of transactions sent from the address. You must increment this nonce each time you send a new transaction with the same address. So if you sign a transaction without broadcasting it, then send a new transaction to the network (with the same address and same nonce), the first raw transaction will automatically be rejected by the miners.

To answer (partially) your question that's not a transaction you sign but message data when you list your NFT for sale. Then you can see on their demo that after approving their contract, the user has to send a second transaction to mint the NFT. Are you sure the newly NFT is not sent on the marketplace contract ?

Related Solutions

solidity – How to Access the Sale Price of an NFT Asset in Your NFT Contract

The order matching information -- buy order, sell order -- is not saved or accessible on chain in a way that your contract can be read during transfers.

There is some way to do what you are saying, but it is not necessarily what you want.

You can disable all ERC-721 transfers in your contract unless they are initiated by your contract itself. So you create your own match order function to evaluate the atomic order and only put the order through if you like it.

This means people cannot buy/sell on OpenSea directly, but they can take those orders and execute on your website.

solidity – Approving ERC721 Token to Unknown Address for Future Purchase

I'm running into the same exact issue. Did you ever solve this?

[SOLVED]

I had to create a second transaction to the NFT ERC721 contract that allowed the NFT Marketplace Contract to be approved to list any of that addresses tokens.

async function allowListing() {
  // connect to the web3 modal and get the signer
  const web3Modal = new Web3Modal();
  const connection = await web3Modal.connect();
  const provider = new ethers.providers.Web3Provider(connection);
  const signer = provider.getSigner();

  // allow token from the NFT contract to be listed on the markeplace
  let contract = new ethers.Contract(nftAddress, NFT.abi, signer);
  let transaction = await contract.setApprovalForAll(nftMarketAddress, true);
  await transaction.wait();
}

Best Answer

Related Solutions

solidity – How to Access the Sale Price of an NFT Asset in Your NFT Contract

solidity – Approving ERC721 Token to Unknown Address for Future Purchase

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