Nft Standards

NFT Standards

Master ERC-721 and ERC-1155 NFT standards, metadata best practices, and advanced NFT features.

When to Use This Skill

• Creating NFT collections (art, gaming, collectibles)
• Implementing marketplace functionality
• Building on-chain or off-chain metadata
• Creating soulbound tokens (non-transferable)
• Implementing royalties and revenue sharing
• Developing dynamic/evolving NFTs

ERC-721 (Non-Fungible Token Standard)

// 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";

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 = MINT_PRICE * quantity, "Insufficient payment");

        for (uint256 i = 0; i  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  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 "...";
    }
}

Royalties (EIP-2981)

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

contract NFTWithRoyalties is ERC721, IERC2981 {
    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);
    }
}

Additional patterns and templates

More detailed templates and worked examples live in references/details.md. Read that file for the full pattern library.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: wshobson
• Source: wshobson/agents
• License: MIT
• Homepage: https://sethhobson.com

Install and usage instructions live in the source repository linked above.