Working with NFTs

Make sure to implement the prerequisite code, or else these examples will not work!

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 { abi as 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 { abi as 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);