/Auction

Primary LanguageSolidity

English Auction NFT Smart Contract

Description

This project implements an English auction smart contract where participants can bid for an NFT. The auction ends after a specified time, and the NFT is transferred to the highest bidder.

Features

  • English auction functionality
  • ERC721 integration
  • Automatic NFT transfer to the highest bidder

FUNCTIONS USAGE

Usage

  1. Deploying the NFT Contract
    • Before starting the auction, deploy an ERC721-compatible NFT contract (e.g., Sepolia NFT-Contract) using your preferred deployment method.
// SPDX-License-Identifier: MIT

// This is a random nft contract that can be used for any contract interactions

pragma solidity ^0.8.4;

import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC721/ERC721.sol";
import "https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol";


contract NftContract is ERC721, Ownable {

  constructor() ERC721("KOXYNFT", "nft") Ownable(msg.sender){}

  function safeMint(address to, uint256 tokenId) public onlyOwner {
      _safeMint(to, tokenId);
  }
}
  1. Minting an NFT
    • In the deployed NFT contract, call the _safeMint function to mint an NFT with a specified token ID to any address of your choice. You can choose any number for the token ID.
 // Assume you have the NFT contract instance
   nftContract.safeMint(yourAddress, tokenId);

  // this is the function being called
  function safeMint(address to, uint256 tokenId) public onlyOwner {
        _safeMint(to, tokenId);
    }
  1. Deploying the Auction Smart Contract

After minting the NFT, deploy the English Auction smart contract. Pass the following parameters: NFT contract address Token ID Starting bid amount Example (using Sepolia NFT-Contract and Auction contract):

constructor(address _nft, uint _nftId, uint _startingBid) {
        nft = IERC721(_nft);
        nftId = _nftId;

        // marked payable to be able to receive ether
        seller = payable(msg.sender);
        highestBid = _startingBid;     
    }
  1. Approving the Auction Contract
    • Call the approve function in the NFT contract, approving the Auction contract to use the NFT
  // Assume you have the NFT contract instance
nftContract.approve(auctionContractAddress, tokenId);

Participating in the Auction

  • Users can bid for the NFT by sending transactions to the smart contract.

Ending the Auction

  • The auction automatically ends after the specified time.
  • The NFT is transferred to the highest bidder.

Deployed Contracts