nft-standards

配套材料的可用性

此目录副本包含以下内联指导，但不包含以下配套路径。它们是外部前置要求，并非随附文件：

• <support-root>/references/erc721.md
• <support-root>/references/erc1155.md
• <support-root>/references/metadata-standards.md
• <support-root>/references/enumeration.md
• <support-root>/assets/erc721-contract.sol
• <support-root>/assets/erc1155-contract.sol
• <support-root>/assets/metadata-schema.json
• <support-root>/assets/metadata-uploader.py

使用依赖这些路径的步骤前，请索取原始配套材料或现有安装；此目录未提供经过验证的下载来源。请根据该安装解析每个路径，检查其内容，并核实适用的许可证和执行前置要求。在所需文件存在之前，请勿运行命令，也不要声称已遵循引用的流程。请勿编造缺失的脚本，也不要将名称相同但无关的文件视为等效文件。此处完整说明的独立步骤可在用户授权范围内继续；请报告任何依赖步骤不可用。

NFT 标准

掌握 ERC-721 和 ERC-1155 NFT 标准、元数据最佳实践及高级 NFT 功能。

不要在以下情况使用此技能

• 任务与 NFT 标准无关
• 你需要使用此范围之外的其他领域或工具

说明

• 明确目标、约束和所需输入。
• 应用相关最佳实践并验证结果。
• 提供可执行的步骤和验证方法。

在以下情况使用此技能

• 创建 NFT 系列（艺术品、游戏、收藏品）
• 实现市场功能
• 构建链上或链下元数据
• 创建灵魂绑定代币（不可转让）
• 实现版税和收益分成
• 开发动态/演化型 NFT

以下内容是 OpenZeppelin 4.x 的示例旧版代码片段，并非经过审计的生产合约。请固定版本并使用经过审查的兼容版本进行编译；OpenZeppelin 5 使用不同的钩子/Ownable 构造函数。缺失的辅助函数主体/元数据/构造函数必须补齐，并在一次性本地区块链上进行测试。审查不意味着进行部署、铸造、资金转移或发布元数据。

ERC-721（非同质化代币标准）

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721Enumerable.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/utils/Counters.sol";
import "@openzeppelin/contracts/utils/Strings.sol";

contract MyNFT is ERC721URIStorage, ERC721Enumerable, Ownable {
    using Counters for Counters.Counter;
    Counters.Counter private _tokenIds;

    uint256 public constant MAX_SUPPLY = 10000;
    uint256 public constant MINT_PRICE = 0.08 ether;
    uint256 public constant MAX_PER_MINT = 20;

    constructor() ERC721("MyNFT", "MNFT") {}

    function mint(uint256 quantity) external payable {
        require(quantity > 0 && quantity <= MAX_PER_MINT, "Invalid quantity");
        require(_tokenIds.current() + quantity <= MAX_SUPPLY, "Exceeds max supply");
        require(msg.value >= MINT_PRICE * quantity, "Insufficient payment");

        // Reserve the entire batch before the first receiver callback.
        uint256 firstId = _tokenIds.current() + 1;
        for (uint256 i = 0; i < quantity; i++) { _tokenIds.increment(); }
        for (uint256 i = 0; i < quantity; i++) {
            uint256 newTokenId = firstId + i;
            _safeMint(msg.sender, newTokenId);
            _setTokenURI(newTokenId, generateTokenURI(newTokenId));
        }
    }

    function generateTokenURI(uint256 tokenId) internal pure returns (string memory) {
        // Return IPFS URI or on-chain metadata
        return string(abi.encodePacked("ipfs://QmHash/", Strings.toString(tokenId), ".json"));
    }

    // Required overrides
    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId,
        uint256 batchSize
    ) internal override(ERC721, ERC721Enumerable) {
        super._beforeTokenTransfer(from, to, tokenId, batchSize);
    }

    function _burn(uint256 tokenId) internal override(ERC721, ERC721URIStorage) {
        super._burn(tokenId);
    }

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

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

    function withdraw() external onlyOwner {
        payable(owner()).transfer(address(this).balance);
    }
}

ERC-1155（多代币标准）

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC1155/ERC1155.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract GameItems is ERC1155, Ownable {
    uint256 public constant SWORD = 1;
    uint256 public constant SHIELD = 2;
    uint256 public constant POTION = 3;

    mapping(uint256 => uint256) public tokenSupply;
    mapping(uint256 => uint256) public maxSupply;

    constructor() ERC1155("ipfs://QmBaseHash/{id}.json") {
        maxSupply[SWORD] = 1000;
        maxSupply[SHIELD] = 500;
        maxSupply[POTION] = 10000;
    }

    function mint(
        address to,
        uint256 id,
        uint256 amount
    ) external onlyOwner {
        require(tokenSupply[id] + amount <= maxSupply[id], "Exceeds max supply");

        tokenSupply[id] += amount; // Effects before ERC-1155 receiver callback.
        _mint(to, id, amount, "");
    }

    function mintBatch(
        address to,
        uint256[] memory ids,
        uint256[] memory amounts
    ) external onlyOwner {
        for (uint256 i = 0; i < ids.length; i++) {
            require(tokenSupply[ids[i]] + amounts[i] <= maxSupply[ids[i]], "Exceeds max supply");
            tokenSupply[ids[i]] += amounts[i];
        }

        _mintBatch(to, ids, amounts, "");
    }

    function burn(
        address from,
        uint256 id,
        uint256 amount
    ) external {
        require(from == msg.sender || isApprovedForAll(from, msg.sender), "Not authorized");
        _burn(from, id, amount);
        tokenSupply[id] -= amount;
    }
}

元数据标准

链下元数据（IPFS）

{
  "name": "NFT #1",
  "description": "Description of the NFT",
  "image": "ipfs://QmImageHash",
  "attributes": [
    {
      "trait_type": "Background",
      "value": "Blue"
    },
    {
      "trait_type": "Rarity",
      "value": "Legendary"
    },
    {
      "trait_type": "Power",
      "value": 95,
      "display_type": "number",
      "max_value": 100
    }
  ]
}

链上元数据

contract OnChainNFT is ERC721 {
    struct Traits {
        uint8 background;
        uint8 body;
        uint8 head;
        uint8 rarity;
    }

    mapping(uint256 => Traits) public tokenTraits;

    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        Traits memory traits = tokenTraits[tokenId];

        string memory json = Base64.encode(
            bytes(
                string(
                    abi.encodePacked(
                        '{"name": "NFT #', Strings.toString(tokenId), '",',
                        '"description": "On-chain NFT",',
                        '"image": "data:image/svg+xml;base64,', generateSVG(traits), '",',
                        '"attributes": [',
                        '{"trait_type": "Background", "value": "', Strings.toString(traits.background), '"},',
                        '{"trait_type": "Rarity", "value": "', getRarityName(traits.rarity), '"}',
                        ']}'
                    )
                )
            )
        );

        return string(abi.encodePacked("data:application/json;base64,", json));
    }

    function generateSVG(Traits memory traits) internal pure returns (string memory) {
        // Generate SVG based on traits
        return "...";
    }
}

版税（EIP-2981）

EIP-2981 用于报告版税信息；它不能强制市场支付版税。请核实市场当前的行为，而不要承诺版税一定会执行。该代码片段假设使用前文所示的导入项以及 IERC165。

import "@openzeppelin/contracts/interfaces/IERC2981.sol";

contract NFTWithRoyalties is ERC721, IERC2981, Ownable {
    address public royaltyRecipient;
    uint96 public royaltyFee = 500; // 5%

    constructor() ERC721("Royalty NFT", "RNFT") {
        royaltyRecipient = msg.sender;
    }

    function royaltyInfo(uint256 tokenId, uint256 salePrice)
        external
        view
        override
        returns (address receiver, uint256 royaltyAmount)
    {
        return (royaltyRecipient, (salePrice * royaltyFee) / 10000);
    }

    function setRoyalty(address recipient, uint96 fee) external onlyOwner {
        require(fee <= 1000, "Royalty fee too high"); // Max 10%
        royaltyRecipient = recipient;
        royaltyFee = fee;
    }

    function supportsInterface(bytes4 interfaceId)
        public
        view
        override(ERC721, IERC165)
        returns (bool)
    {
        return interfaceId == type(IERC2981).interfaceId ||
               super.supportsInterface(interfaceId);
    }
}

灵魂绑定代币（不可转让）

contract SoulboundToken is ERC721 {
    uint256 private nextTokenId;
    constructor() ERC721("Soulbound", "SBT") {}

    function _beforeTokenTransfer(
        address from,
        address to,
        uint256 tokenId,
        uint256 batchSize
    ) internal virtual override {
        require(from == address(0) || to == address(0), "Token is soulbound");
        super._beforeTokenTransfer(from, to, tokenId, batchSize);
    }

    function mint(address to) external {
        uint256 tokenId = ++nextTokenId; // Monotonic ID; burns never permit reuse.
        _safeMint(to, tokenId);
    }

    // Burn is allowed (user can destroy their SBT)
    function burn(uint256 tokenId) external {
        require(ownerOf(tokenId) == msg.sender, "Not token owner");
        _burn(tokenId);
    }
}

动态 NFT

contract DynamicNFT is ERC721 {
    struct TokenState {
        uint256 level;
        uint256 experience;
        uint256 lastUpdated;
    }

    mapping(uint256 => TokenState) public tokenStates;

    function gainExperience(uint256 tokenId, uint256 exp) external {
        require(ownerOf(tokenId) == msg.sender, "Not token owner");

        TokenState storage state = tokenStates[tokenId];
        state.experience += exp;

        // Level up logic
        if (state.experience >= state.level * 100) {
            state.level++;
        }

        state.lastUpdated = block.timestamp;
    }

    function tokenURI(uint256 tokenId) public view override returns (string memory) {
        TokenState memory state = tokenStates[tokenId];

        // Generate metadata based on current state
        return generateMetadata(tokenId, state);
    }

    function generateMetadata(uint256 tokenId, TokenState memory state)
        internal
        pure
        returns (string memory)
    {
        // Dynamic metadata generation
        return "";
    }
}

Gas 优化铸造（ERC721A）

import "erc721a/contracts/ERC721A.sol";

contract OptimizedNFT is ERC721A {
    uint256 public constant MAX_SUPPLY = 10000;
    uint256 public constant MINT_PRICE = 0.05 ether;

    constructor() ERC721A("Optimized NFT", "ONFT") {}

    function mint(uint256 quantity) external payable {
        require(_totalMinted() + quantity <= MAX_SUPPLY, "Exceeds max supply");
        require(msg.value >= MINT_PRICE * quantity, "Insufficient payment");

        _mint(msg.sender, quantity);
    }

    function _baseURI() internal pure override returns (string memory) {
        return "ipfs://QmBaseHash/";
    }
}

资源

• references/erc721.md：ERC-721 规范详情
• references/erc1155.md：ERC-1155 多代币标准
• references/metadata-standards.md：元数据最佳实践
• references/enumeration.md：代币枚举模式
• assets/erc721-contract.sol：生产级 ERC-721 模板
• assets/erc1155-contract.sol：生产级 ERC-1155 模板
• assets/metadata-schema.json：标准元数据格式
• assets/metadata-uploader.py：IPFS 上传工具

最佳实践

1. 使用 OpenZeppelin：经过实战检验的实现
2. 固定元数据：使用带固定服务的 IPFS
3. 实现版税：使用 EIP-2981 以兼容市场
4. Gas 优化：批量铸造时使用 ERC721A
5. 揭示机制：占位符 → 揭示模式
6. 枚举：支持 walletOfOwner，以便适配市场
7. 白名单：使用 Merkle 树实现高效白名单

市场集成

• OpenSea：ERC-721/1155、元数据标准
• 市场的版税行为因政策和版本而异；在作出相关声明前请先核实
• Rarible：协议费用、延迟铸造
• Blur：燃料费优化交易

局限性

• 仅当任务明确符合上述范围时，才使用此技能。
• 不要将输出视为可替代特定环境的验证、测试或专家审查。
• 如果缺少必需的输入、权限、安全边界或成功标准，请停止并请求澄清。