Working with NFTs

Make sure to implement the prerequisite code, or else the examples in this page will not work!

Prerequisite: erc721ABI JSON file

When working with NFT, and for some use-cases described in this page (the ones that import erc721ABI), you will need the below ERC721Abi.json file saved in your project folder.

Make sure that you import that file in your code in order to achieve the wanted step (the samples already have the necessary import code).

12KB

ERC721Abi.json

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Retrieve user NFT list

To retrieve all NFTs held in user wallet, you need a third-party tool or API.

In this example, we use Nansen API's GET /address/portfolio endpoint.

const options = {method: 'GET', headers: {accept: 'application/json'}};

fetch('https://api.nansen.ai/v1/address/portfolio', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

Retrieve user NFT details

Once you know the NFT's smart-contract address (using the code above), you can get all its metadata:

import erc721ABI from './ERC721ABI.json';

const contractAddress = '0xYourNFTAddress'; // Replace with the actual contract address

async function getNFTMetadata(tokenId) {
    const tokenURI = await client.readContract({
        address: contractAddress, // Contract address of the NFT
        abi: erc721ABI,
        functionName: 'tokenURI', // Standard ERC-721 function to get metadata uri
        args: [tokenId], // User's address whose balance you want to check
    });

    const metadataResponse = await fetch(tokenURI);
    const metadata = await metadataResponse.json();
    console.log(metadata);
}

// Example usage: Get metadata for a specific token (e.g., token ID 1)
getNFTMetadata(1);

Retrieve user NFT balance

This code will allow you to check how many NFTs from a specific collection a user holds.

It is much lighted than the "Retrieve user NFT list" example that uses Nansen shown above.

import erc721ABI from './ERC721ABI.json';

async function getNFTBalance() {
  const balance = await client.readContract({
    address: '0xYourNFTAddress', // Replace with the actual NFT contract address
    abi: erc721ABI,
    functionName: 'balanceOf', // Standard ERC-721 function to get balance
    args: ['0xUserWalletAddress'], // User's address whose NFT balance you want to check
  });
  return balance.toString();
}

// Example usage
getNFTBalance().then(console.log);