Building an NFT Marketplace Smart Contract with Solidity and OpenZeppelin

This blog post explains how to create a simple decentralized NFT marketplace using Solidity. The marketplace allows users to list NFTs for sale, purchase NFTs, and manage ownership while ensuring security against reentrancy attacks. The contract imports OpenZeppelin libraries for ERC721, counters, and reentrancy protection. The contract owner earns a listing fee for every NFT listed. A struct is used to store the details of each listed NFT, and a mapping is used to access each NFT by its ID. Users can list their NFTs on the marketplace by specifying the contract address, token ID, and price, and paying a small listing fee. The marketplace contract transfers the NFT ownership and the ether between buyer and seller when an NFT is purchased. Users can fetch NFTs that are available for sale, those they own, or ones they have created. The contract ensures security and ease of use for the marketplace by leveraging OpenZeppelin libraries and reentrancy protection. The marketplace allows users to securely list, buy, and manage NFTs while paying small listing fees.