erc721-patterns

ERC-721 NFT Patterns

Standard Interface

interface IERC721 {
    function balanceOf(address owner) external view returns (uint256);
    function ownerOf(uint256 tokenId) external view returns (address);
    function safeTransferFrom(address from, address to, uint256 tokenId) external;
    function transferFrom(address from, address to, uint256 tokenId) external;
    function approve(address to, uint256 tokenId) external;
    function setApprovalForAll(address operator, bool approved) external;
    function getApproved(uint256 tokenId) external view returns (address);
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

Full NFT Contract Template

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import {ERC721Enumerable} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import {ERC721URIStorage} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import {ERC721Royalty} from "@openzeppelin/contracts/token/ERC721/extensions/ERC721Royalty.sol";
import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {Strings} from "@openzeppelin/contracts/utils/Strings.sol";

contract MyNFT is ERC721, ERC721Enumerable, ERC721URIStorage, ERC721Royalty, Ownable {
    uint256 private _nextTokenId;
    string private _baseTokenURI;
    uint256 public maxSupply;
    uint256 public mintPrice;

    constructor(
        string memory name_,
        string memory symbol_,
        string memory baseURI_,
        uint256 maxSupply_,
        uint256 mintPrice_,
        uint96 royaltyBps // e.g. 500 = 5%
    ) ERC721(name_, symbol_) Ownable(msg.sender) {
        _baseTokenURI = baseURI_;
        maxSupply = maxSupply_;
        mintPrice = mintPrice_;
        _setDefaultRoyalty(msg.sender, royaltyBps);
    }

    function mint(address to) external payable {
        require(msg.value >= mintPrice, "Insufficient payment");
        require(_nextTokenId < maxSupply, "Max supply reached");
        uint256 tokenId = _nextTokenId++;
        _safeMint(to, tokenId);
    }

    function _baseURI() internal view override returns (string memory) {
        return _baseTokenURI;
    }

    function setBaseURI(string calldata newBaseURI) external onlyOwner {
        _baseTokenURI = newBaseURI;
    }

    function withdraw() external onlyOwner {
        (bool ok,) = msg.sender.call{value: address(this).balance}("");
        require(ok, "Withdraw failed");
    }

    // Required overrides
    function _update(address to, uint256 tokenId, address auth)
        internal
        override(ERC721, ERC721Enumerable)
        returns (address)
    {
        return super._update(to, tokenId, auth);
    }

    function _increaseBalance(address account, uint128 value)
        internal
        override(ERC721, ERC721Enumerable)
    {
        super._increaseBalance(account, value);
    }

    function tokenURI(uint256 tokenId)
        public view override(ERC721, ERC721URIStorage) returns (string memory)
    {
        return super.tokenURI(tokenId);
    }

    function supportsInterface(bytes4 interfaceId)
        public view override(ERC721, ERC721Enumerable, ERC721URIStorage, ERC721Royalty) returns (bool)
    {
        return super.supportsInterface(interfaceId);
    }
}