Skip to main content

Build Multi-Chain NFT Scanner

In this guide, we will use Bitquery Streaming API for scanning NFTs (Non-Fungible Tokens) across various blockchains for the given address. We'll explore how to build an NFT scanner that works with a specific wallet address using Python.

Additionally, we will delve into using the Bitquery Explorer and IDE for broadening your knowledge of blockchain exploration. To get started for free, please create an account on Bitquery IDE with your email to get your API key and access to the bit query IDE.

Why Bitquery for NFT Scanning?​

  • Multi-Blockchain Support: Bitquery covers a wide range of blockchains, providing a holistic view of the NFT marketplace.
  • Real-Time Data: Access up-to-the-minute information on NFT transactions and holdings.
  • Customizable Queries: With GraphQL, tailor your queries to fetch exactly what you need, without unnecessary data overhead.

Using Bitquery IDE for Custom Queries​

For a more tailored experience:

  1. Open Bitquery IDE: Access the IDE in your browser.
  2. Write and Run Queries: Utilize the IDE to write custom GraphQL queries. For instance, you can modify the earlier NFT balance query to suit other blockchains or different parameters.
  3. Analyze the Results: Execute your queries and analyze the data returned directly in the IDE.

The following query can be used to display the primary metadata for NFTs on any blockchain. Make sure the schema being used if from (https://streaming.bitquery.io/graphql) 

query ($network: evm_network, $limit: Int!, $offset: Int!, $address: String) {
  EVM(dataset: combined, network: $network) {
    BalanceUpdates(
      orderBy: {descendingByField: "amount"}
      limit: {offset: $offset, count: $limit}
      where: {BalanceUpdate: {Address: {is: $address}}, Currency: {Fungible: false}}
    ) {
      Currency {
        Name
        Symbol
        SmartContract
      }
      BalanceUpdate {
        Address
        Id
        URI
      }
      amount: sum(of: BalanceUpdate_Amount)
      Block {
        Time(maximum: Block_Time)
      }
      count
      ChainId
      Transaction {
        Hash
      }
    }
  }
}

Below the sections, where we write the query. There is arguments section, where we can input our arguments like network, limit, address, etc. as JSON object. 

{
    "network": "eth",
    "limit": 10,
    "offset": 0,
    "address": "0x771c82dd5c6e1011adcf4372e77cf5e5587a9054"
}

Now we can use the export code tool to create simple CLI based tools to scan various blockchains for NFTs in any of the languages available in the drop down.

Let’s quickly build a python script for the same to make the data more readable and accessible.

  1. Install the Requests Library:

The requests library is used to make HTTP requests in Python. Install it using pip:

pip install requests
  1. Export the code using the export code snippet button on the top right of (https://ide.bitquery.io/).

Code Export Window on Biquery IDE

  1. Modifying for better readability
import requests
import json

def fetch_nft_data(wallet_address, api_key, block_chain):
    url = "https://streaming.bitquery.io/graphql"

    # GraphQL query payload
    payload = json.dumps({
        "query": """
        query ($network: evm_network, $limit: Int!, $offset: Int!, $address: String) {
            EVM(dataset: combined, network: $network) {
                BalanceUpdates(
                    orderBy: {descendingByField: "amount"}
                    limit: {offset: $offset, count: $limit}
                    where: {BalanceUpdate: {Address: {is: $address}}, Currency: {Fungible: false}}
                ) {
                    Currency {
                        Name
                        Symbol
                        SmartContract
                    }
                    BalanceUpdate {
                        Address
                        Id
                        URI
                    }
                    amount: sum(of: BalanceUpdate_Amount)
                    Block {
                        Time(maximum: Block_Time)
                    }
                    count
                    ChainId
                    Transaction {
                        Hash
                    }
                }
            }
        }
        """,
        "variables": json.dumps({
            "network": block_chain,
            "limit": 100,
            "offset": 0,
            "address": wallet_address
        })
    })

    # API headers
    headers = {
        'Content-Type': 'application/json',
         Authorization: "Bearer your_access_token_here",
    }

    # Make the API request
    response = requests.post(url, headers=headers, data=payload)

    # Parse the JSON response
    data = response.json()

    # Check if 'data' key is in the response
    if 'data' in data:
        return data['data']['EVM']['BalanceUpdates']
    else:
        raise Exception("No data found or error in response")

def main():
    api_key = "YOUR_BITQUERY_API_KEY"  # Replace with your Bitquery API key
    wallet_address = input("Enter Ethereum wallet address: ")
    block_chain = input("Enter block chain name(eth, bsc, arbitrum, any evm): ") #see blockchain identifiers in IDE
    try:
        balance_updates = fetch_nft_data(wallet_address, api_key,block_chain) #default eth
        
      
        total_nfts = sum(int(item['count']) for item in balance_updates if item['count'])
        print(f"Total NFTs in Wallet: {total_nfts}")

        has_nfts = "Yes" if total_nfts > 0 else "No"
        print(f"Does Wallet Have NFTs? {has_nfts}")

    except Exception as e:
        print("An error occurred:", str(e))

if __name__ == "__main__":
    main()
  1. Run code in terminal

NFT scanner output

This code displays whether a wallet holds NFT’s on a blockchain and how many it holds. In order to see the specifics of the NFTs held in the wallet the following snippet can be added to view the json dump which we already formatted in the above code.

for item in balance_updates:
    # Format and print each item in a human-readable way
    print(json.dumps(item, indent=2))

Exploring NFTs Beyond Code: Bitquery Explorer​

Bitquery Explorer for Easy Exploration​

For those who prefer a GUI over code:

  • Visit Bitquery Explorer (https://explorer.bitquery.io/) : Navigate to the Explorer on your web browser.

  • Select the Blockchain: Choose the blockchain from which you want to fetch NFT data.

  • Input the Wallet Address: Search for the specific wallet address in the provided search bar.

Click on the NFT’s on Address Tab: The Explorer will display NFT transactions and holdings associated with the address, offering a detailed view of the NFT landscape related to that wallet.