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NFT Smart Contract Explained

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    NFT Smart Contract Explained

    NFTs have already become real game-changers in the digital assets and collectibles industry. The number of artists, content creators, and digital art lovers moving into the NFT industry is constantly increasing. It’s a place for people to buy or sell different digital artworks and maintain ownership of unique assets.

    However, even though NFTs and other digital platforms are widely known, many people have no idea about smart contracts and their significant role in the NFT industry. But, in reality, they are irreplaceable as NFT’s main function is directly related to smart contracts.

    So, let’s see what smart contracts are and how they affect NFTs.

    What are Smart Contracts, and How Do They Work?

    Understanding the basics and functions of smart contracts is an essential step for collectors and content creators to mint NFTs successfully. A smart contract is a piece of code based on the blockchain. Its primary role is to execute when specific predetermined conditions are met automatically. These conditions are generally the agreements between various parties involved. The entire process is carried out without third parties.

    As you already have a general idea of a smart contract, let’s move on to NFT smart contracts. In terms of NFTs, ownership rights, identity, and financial transaction details are stored in underlying smart contracts. Simply put, the uniqueness and individuality of each NFT minted result from its smart contract functions. Beyond simple financial transactions and basic information, NFT creators can also put other details and terms into smart contracts while creating NFTs. They can include linking to another digital asset or granting certain rights to a group of people.

    NFT Smart Contracts: How to Read Them?

    You will indeed wonder why you should read NFT smart contracts. All the valuable information you need to know about a particular NFT project is based on smart contracts. Reading a smart contract can give you all the details you are interested in: the ownership rights, project’s popularity, transaction details, etc. Moreover, you can directly get your NFTs minted on smart contracts without other procedures.

    The first thing you need to do is find a smart contract. So, below are the instructions you can look through.

    1. Go to OpenSea and find the NFT you are interested in.
    2. Click on the arrow on the tab “Details.”
    3. Here, you will see the line “Contract Address.” Click on it.
    4. You will be redirected to the Etherscan website, where you can find the smart contract’s data: wallet address, blocks, etc.
    5. Paste the address of the smart contract in the search bar and view the details.

    Now, you have the details of the NFT smart contract. Let’s move on and explore what you can understand from it.

    General Information

    Here, you will see:

    • Creator: It includes the wallet address of the person who created the smart contract, and a link leading to the original transaction. You can see all the details related to the transaction, such as block, timestamp, transaction hash, and more.
    • Balance: It shows coin numbers the contract holds.
    • My Name Tag: It’s for adding your notes to the preferred projects. This option is available only if you are logged into your Etherscan account.

    Internal Transactions

    Besides general transaction details, you can also find internal transactions. These are the transactions between the contracts: the value transfers coming from the smart contracts execution process.

    Tracker Details

    Token tracker gives you all the token information you need to know: official website, total transactions, minimum price, social profiles, and maximum total supply.

    Contract Information 

    You can find all the specific information about the NFT smart contract in the “Code” tab. Here are two options: “Read Contract,” where you can see general info and functions of the contract, and the “Write Contract” option, which allows you to interact with the smart contract.


    This tab includes all the information concerning the token, its transactions, transfers, timelines, general trends of the NFT project, etc.

    NFT Smart Contract Creation and Deployment

    You don’t need programming skills for deploying your NFTs. Just follow the steps below to make it done.

    Create an Account on Alchemy 

    First of all, you need to create an account on Alchemy. After creating an account, you can already click on “Create App” and fill in the required details: Name, Chain, Environment, and Network.

    Add Your MetaMask Wallet

    After creating an account, you need to have a digital wallet connected to your Alchemy account so that you can easily make and receive transactions later. The most popular is the MetaMask wallet. 

    Connect to the Ethereum Network

    During the process of smart contract deployment, you need to have some tokens for transactions and gas fees. You can use the ETH (Ethereum) from your MetaMask account. Before moving on to the next steps, go to Ethereum and open an account.

    Install HardHat

    The development environment of HardHat helps with implementing smart contracts locally. 

    Run the following on the command line:

    • npm install – – save-dev hardhatnpx hardhat

    This npx hardhat helps to create a hardhat project. 

    Organize the Project Folder

    Here, you need to create two folders:

    1. Scripts: Scripts location for deploying and interacting with your smart contract.
    2. Contracts: It’s the location of your NFT smart contract code.

    Then, run the following code in the command line. It’s important to note that you should be in your NFT root directory. 

    • mkdir scriptsmkdir contracts

    Time to Write The Smart Contract!

    After the environmental setup is done, we can move on to the coding part. Here, you will use Solidity for writing new smart contracts.

    Run the following in the command line for installing an OpenZeppelin library to your folder:

    • npm install@openzeppelin/contracts

    Then, go to the “contracts” folder and make a new file MyNFT.sol

    Here, you will import three smart contract classes of OpenZeppelin.

    • @openzeppelin/contracts/token/ERC721/ERC721.sol

    This includes the ERC-721 standard implementation. When importing this statement, the smart contract gets all the methods of ERC-721. In the ERC-721 constructor, you will see two strings: NFTC and NFTCreator. The first variable is the symbol of the smart contract, and the second one is its name. These variables are for input:

    • String memory tokenURI: the uniform resource identifier of the NFT Metadata.
    • Address recipient: it is the address where NFTs are sent.

    Connect Alchemy and MetaMask to Your Project 

    To safely store your MetaMask private key and Alchemy API key, you must create an environment file. It will be able to interlink the MetaMask and Alchemy key with your project. You can install the package called dotenv, where you can load your environmental variables.

    Update HardHat and Install Ether.js

    Many actions have been made, so there is a need to update your HardHat. You also need to install Ether.js for deploying the contract.

    Compile the Contract and Write the Deploy Script

    For compiling, fill this in the command line:

    • npx hardhat compile

    As for the deployment script, go to the folder “Scripts” and create a file “deploy.js“.

    Deploy the Smart Contract

    We have already learned to deploy the smart contract. In the command line, fill in the following:

    • npx hardhat runscripts/deploy.js – – network 

    You can use the Ropsten etherscan to see the contract deployed. In the transaction sector, you will see the details of your MetaMask account address, content creator, contract address, etc. Now, it’s all set up, and your sample project of the NFT smart contract is already deployed.


    How to create NFT smart contracts?

    Almost anyone with basic skills and knowledge can create smart contracts. There are several steps to follow.

    1. Install the CLI tool
    2. Set the network
    3. Add gas
    4.Deploy and mint the NFTs
    5. Transfer NFTs

    How much does it cost to make an NFT?

    Generally, you need to pay a gas fee for creating an NFT, listing fees, or site fees. The costs can be minimal, but sometimes they can reach up to $900.

    Where to sell NFT art?

    You can buy and sell NFTs on various marketplaces like OpenSea, Foundation, and Rarible.

    How to mint an NFT?

    Here are the brief steps on how most NFTs are minted:

    1. Install Web3 
    2. Create a Mint-NFT.js file
    3. Grab the API of your contract
    4. Configure your NFT Metadata
    5. Create an example of your contract
    6. Update the .env file
    7. Create and sign your transaction 
    8. Call MintNFT and run MintNFT.js

    What is MetaMask?

    Metamask is a digital wallet used to connect with the Ethereum blockchain. It enables users to access their wallets through a mobile app or website extension.