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BRC-721: NFTs
The BRC-721 token standard on Bitcoin is similar to ERC-721 on Ethereum. It can represent virtually anything in Bitcoin:
- collectible items
- memberships
- lottery tickets
- in-game items
- and more
Extending the OpenZeppelin ERC-721 contract, we can create a hypothetical PFP NFT collection (CryptoWizards) on Bitcoin.
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
contract CryptoWizards is ERC721URIStorage {
constructor() ERC721("CryptoWizards", "WIZ") {}
function safeMint(address to, uint256 tokenId, string memory uri) public {
_safeMint(to, tokenId);
_setTokenURI(tokenId, uri);
}
}
To compile your contracts, use the built-in
hardhat compile task.cd smart-contract-examples
npm install
npx hardhat compile
Review config file
hardhat.config.ts. The network configs should look like this. networks: {
mynw: {
url: "http://localhost:10002",
accounts: {
mnemonic: "<your mnemonic with funds>"
},
timeout: 100_000,
},
blockscoutVerify: {
blockscoutURL: "http://localhost:4000", // your explorer URL
...
}
}
Run the deploy scripts using
hardhat-deploy.npx hardhat deploy --tags NFT
Make sure the accounts in hardhat.config.ts have some TC.
Once the contracts are deployed, you can interact with them. We've prepared a few
hardhat tasks to make it easy for you to interact with the contracts.# ./CryptoWizards/wizard100.jpg
npx hardhat mint-nft --metadata wizard100.json --tokenid 100
# output should contain the URI
npx hardhat get-nft --uri bfs://22213/0xfe94d57c6ef567d26e3524f54dc2772329092ffd/0xd3b0932Dff95a56c6024328162a3040F5e717F76/100