How to Deploy an ERC-721 NFT Contract on Avalanche

Deploying your own NFT smart contract on the Avalanche network is an exciting way to enter the world of digital collectibles. This guide walks you through the entire process, from preparing your assets to interacting with your deployed contract, using testnet environments to ensure safety and familiarity before any real funds are involved.

What You Will Need

Before starting, make sure you have the following tools and accounts set up:

• A Pinata account for storing NFT images and metadata on IPFS.
• The Core browser extension wallet installed and configured.
• Access to the Avalanche Fuji Testnet for deployment practice.
• Familiarity with basic concepts of smart contracts and NFTs.

These resources are all freely available and designed for developer use.

Preparing Your NFT Files

The first step in creating an NFT collection is preparing your digital assets. This involves two components:

• The image, video, or audio file that constitutes the NFT’s primary content.
• A metadata file in JSON format that describes the NFT's properties, including a link to the media file.

Both files should be uploaded to a decentralized storage service like IPFS via Pinata to ensure they remain accessible and immutable. Once uploaded, note the base URI provided by Pinata for your folder, as this will be essential for your smart contract.

Configuring Your Wallet and Network

To interact with the Avalanche Fuji Testnet, you need to configure your Web3 wallet.

Enabling Testnet Mode

If you are using the Core wallet extension, enable Testnet Mode in the Advanced Settings. This automatically switches the wallet to the Fuji Testnet environment.

Adding Fuji Testnet Manually

For other Web3 wallets like MetaMask, you may need to add the Avalanche Fuji Testnet manually using the following parameters:

• Network Name: Avalanche Fuji C-Chain
• New RPC URL: https://api.avax-test.network/ext/bc/C/rpc
• ChainID: 43113
• Currency Symbol: AVAX
• Block Explorer: https://testnet.snowtrace.io

Acquiring Testnet AVAX

Since deploying a smart contract requires paying transaction fees (gas), you need testnet AVAX tokens on the Fuji network. You can obtain these through:

• The official Avalanche Testnet Faucet.
• Requesting a faucet coupon via the Avalanche Guild.
• Asking moderators on the official Avalanche Discord server if other methods are unavailable.

Paste your wallet's C-Chain address into the faucet to receive test tokens.

Building the ERC-721 Smart Contract

We will use OpenZeppelin's Contract Wizard, a powerful tool for generating secure and standard-compliant smart contract code.

Using the OpenZeppelin Wizard

1. Navigate to the OpenZeppelin Contract Wizard.
2. Select ERC-721 as the contract standard.

3. Fill in the details for your NFT collection:

   • Name: Enter a name for your collection (e.g., "MyPhotographs").
   • Symbol: Enter a ticker symbol (e.g., "FOTO").
   • Base URI: Paste the full IPFS gateway URL to your metadata folder from Pinata.

Configuring Contract Features

For this tutorial, enable the following features in the wizard:

• Mintable: Adds a function to create new NFTs.
• Auto Increment Ids: Ensures each new NFT receives a unique, sequential token ID.
• Ownable: Restricts the minting function to the contract owner.

Click "Open in Remix" to export your generated contract code to the Remix IDE for further editing and deployment.

Compiling and Deploying the Contract

The Remix IDE provides a full environment for handling your smart contract without local setup.

Compiling the Contract

1. In Remix, ensure your contract code is visible.
2. Press Ctrl+S (or Cmd+S on Mac) or click the "Compile" button to compile the Solidity code.
3. A green checkmark indicates a successful compilation.

Deploying to Fuji Testnet

1. Navigate to the "Deploy & Run Transactions" tab in Remix.
2. Under "Environment," select "Injected Web3." This will connect Remix to your Core wallet.
3. Ensure your Core wallet is connected to the Fuji Testnet.
4. In the "Contract" dropdown, select your ERC-721 contract.
5. Click "Deploy." Your Core wallet will prompt you to confirm the transaction. Confirm it.
6. After confirmation, your contract address will appear in Remix under "Deployed Contracts."

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Verifying the Deployment

Use the Snowtrace Testnet Explorer to verify your contract was deployed successfully.

1. Copy your contract's address from Remix.
2. Paste it into the search bar on Snowtrace and click "Search."
3. You will see the contract's details and the initial deployment transaction.

Minting Your First NFT

With the contract deployed, you can now mint an NFT.

1. Back in Remix, under "Deployed Contracts," find your contract and click to expand it.
2. Find the safeMint function and expand it.
3. Paste your wallet address into the address field. This determines who receives the minted NFT.
4. Click "transact." Your wallet will prompt you to confirm the minting transaction and pay a small gas fee.
5. Once confirmed, the transaction will appear on Snowtrace. Clicking the transaction hash will show the details of your newly created NFT.

Moving to Mainnet

Once you are comfortable with the process on the testnet, you can deploy your contract on the Avalanche C-Chain Mainnet. The steps are identical, with three critical changes:

• Ensure your Core wallet is switched to the Avalanche C-Chain Mainnet.
• Fund your wallet with real AVAX tokens to pay for deployment and minting gas fees.
• Use the main Snowtrace Explorer to view your contracts and transactions.

Always audit your code or have it professionally reviewed before a mainnet deployment to ensure security and functionality.

Frequently Asked Questions

What is an ERC-721 contract?
ERC-721 is a free, open standard that describes how to build non-fungible or unique tokens on the Ethereum Virtual Machine (EVM). Unlike fungible tokens (like AVAX), each ERC-721 token is unique and is used to represent ownership of unique digital or physical assets.

Why use the Avalanche network for NFTs?
Avalanche offers extremely fast transaction finality and low gas fees compared to other networks. Its compatibility with the Ethereum toolset (like MetaMask and Remix) makes it easy for developers to build and deploy without learning entirely new technologies.

Can I sell the NFTs I create on a marketplace?
Yes. Once your ERC-721 contract is deployed on the mainnet, you can list your NFTs for sale on any marketplace that supports the Avalanche C-Chain, such as NFTrade or Kalao. The process for listing is specific to each marketplace.

Is the mint function in this tutorial open to the public?
No. In this guide, the safeMint function is protected by an onlyOwner modifier, meaning only the wallet that deployed the contract can mint NFTs. For a public sale, you would need to modify the contract to remove this restriction and typically add a payment requirement.

What does the Base URI refer to?
The Base URI is the base URL that points to the folder where your NFT metadata JSON files are stored on IPFS. The smart contract appends the token ID to this URI to form the complete URL for each token's metadata (e.g., BaseURI + "/1.json").

Are there costs involved besides gas fees?
Using Pinata for IPFS storage has free tiers suitable for testing. However, for large-scale mainnet projects, you may incur costs for dedicated IPFS pinning services to ensure your metadata remains available long-term.