NFT App Development Company

// SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import "@openzeppelin/contracts/token/ERC721/IERC721.sol"; import "@openzeppelin/contracts/security/ReentrancyGuard.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; /// @title NFT Marketplace with Royalty Support /// @notice Escrow-based listing with on-chain settlement contract NFTMarketplace is ReentrancyGuard, Ownable { uint256 private _listingCount; uint256 public listingFee = 0.025 ether; uint256 public platformFee = 250; // 2.5% in basis points struct Listing { uint256 listingId; address nftContract; uint256 tokenId; address payable seller; uint256 price; bool active; } mapping(uint256 => Listing) public listings; event ItemListed(uint256 indexed listingId, address indexed seller, uint256 price); event ItemSold(uint256 indexed listingId, address buyer, uint256 price); /// @notice List an NFT for sale function listItem( address nftContract, uint256 tokenId, uint256 price ) external payable nonReentrant returns (uint256) { require(price > 0, "Price must be > 0"); require(msg.value == listingFee, "Insufficient fee"); IERC721(nftContract).transferFrom(msg.sender, address(this), tokenId); _listingCount++; listings[_listingCount] = Listing( _listingCount, nftContract, tokenId, payable(msg.sender), price, true ); emit ItemListed(_listingCount, msg.sender, price); return _listingCount; } /// @notice Buy a listed NFT with royalty enforcement function buyItem(uint256 listingId) external payable nonReentrant { Listing storage listing = listings[listingId]; require(listing.active, "Listing not active"); require(msg.value == listing.price, "Incorrect price"); listing.active = false; // Calculate and pay royalty via ERC-2981 if supported try IERC2981(listing.nftContract).royaltyInfo( listing.tokenId, msg.value ) returns (address receiver, uint256 amount) { if (amount > 0 && receiver != address(0)) { payable(receiver).transfer(amount); listing.seller.transfer(msg.value - amount); } } catch { listing.seller.transfer(msg.value); } IERC721(listing.nftContract).transferFrom( address(this), msg.sender, listing.tokenId ); emit ItemSold(listingId, msg.sender, msg.value); } }