Upfront Smart Contract Integration (EVM)

📋 Overview

Upfront integration allows your players to purchase NFTs with full payment in a single transaction. The NFT is transferred directly to the user with no restrictions, wrapping, or installment tracking required.

✅ Integration Requirements

✓

ERC721/ERC1155 Compliance

Your NFT collection must follow standard ERC721 or ERC1155 interfaces.
✓

Marketplace Integration

Your marketplace must be able to call the MersoUpfront contract.
✓

No wNFT Required

Upfront purchases transfer the original NFT directly—no WrappedNFT support needed.

📝 Contract Interface

MersoUpfront Interface

Solidity

interface IMersoUpfront {
    // Purchase an NFT with full upfront payment
    function buyTokenFrom(
        address originalCollection,
        uint256 tokenId,
        uint256 tokenPrice,
        address tokenAddress
    ) external;
    
    // Check if a collection is allowed
    function isAllowedCollection(
        address collection
    ) external view returns (bool);
}

💻 Integration Example

Frontend Integration

JavaScript

import { ethers } from 'ethers';
import MersoUpfront_ABI from './abis/MersoUpfront.json';

const MERSO_UPFRONT_ADDRESS = '0x...'; // Provided during onboarding

async function purchaseUpfront(collection, tokenId, price, paymentToken) {
    const provider = new ethers.providers.Web3Provider(window.ethereum);
    const signer = provider.getSigner();
    
    // 1. Approve full payment amount
    const tokenContract = new ethers.Contract(paymentToken, ERC20_ABI, signer);
    await tokenContract.approve(MERSO_UPFRONT_ADDRESS, price);
    
    // 2. Execute upfront purchase
    const mersoContract = new ethers.Contract(MERSO_UPFRONT_ADDRESS, MersoUpfront_ABI, signer);
    const tx = await mersoContract.buyTokenFrom(
        collection,
        tokenId,
        price,
        paymentToken
    );
    
    await tx.wait();
    console.log('Upfront purchase complete! Original NFT transferred to user.');
}

⚖️ Upfront vs PNPL Comparison

Feature	Upfront	PNPL
Payment Amount	100% upfront	50% upfront + 4 weekly
NFT Received	Original NFT	WrappedNFT (then original)
Transfer Restrictions	None	During payment period
Integration Complexity	Lower	Higher (wNFT support)