Cartee - MNEE Payment Gateway

MNEE payment gateway for woo-commerce and shopify. Pay and accept MNEE token in e-commerce stores.

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Cartee - MNEE Stablecoin Payment Gateway

Inspiration

The global e-commerce market reached $5.8 trillion in 2023, with over 8 million merchants on Shopify and WooCommerce. Meanwhile, 420 million people hold $1.7 trillion in crypto assets. Yet these ecosystems are completely disconnected less than 0.01% of merchants accept cryptocurrency. Existing solutions like Coinbase Commerce charge 1-2% fees, require KYC, use custodial wallets, and impose multi-day settlements.

The opportunity: Millions of merchants want crypto customers, millions of crypto users want to spend their assets, but no seamless solution exists. MNEE stablecoin solves this. Cartee enables direct, non-custodial MNEE payments on Shopify (4.4M stores) and WooCommerce (3.9M stores) bridging Web3 wealth with real-world commerce through MNEE stablecoin infrastructure.

What it does

Cartee enables MNEE stablecoin payments on Shopify and WooCommerce (8.3M merchants, $600B annual volume). Customers select "MNEE Token Payment" at checkout, connect their wallet (300+ supported via RainbowKit), approve and send MNEE. Our blockchain listener detects transfers instantly and updates order status automatically.

Key Features:

  • WooCommerce: One-click plugin install, 5-minute setup
  • Shopify: Webhook integration with automatic payment links
  • Direct Invoicing: Custom B2B payment links from dashboard
  • Non-Custodial: MNEE flows wallet-to-wallet, we never hold funds
  • No KYC/Fees: Zero platform fees, only network gas

Cartee was architected from day one to handle production-scale MNEE stablecoin transactions with enterprise-grade reliability. Our tech stack prioritizes speed, security, and seamless Web3 integration.

Frontend & Merchant Dashboard:

  • Next.js 15 with React 19 and App Router for server-side rendering and optimal performance
  • RainbowKit for universal wallet connectivity supporting MetaMask, WalletConnect, Coinbase Wallet, and 300+ Web3 wallets
  • wagmi & viem for type-safe blockchain interactions and MNEE contract communication
  • Tailwind CSS for responsive, modern UI design ## How we built it

Tech Stack:

  • Frontend: Next.js 15, React 19, RainbowKit (300+ wallet support), wagmi/viem, Tailwind CSS, Vercel deployment
  • Backend: Prisma + PostgreSQL (Supabase), RESTful APIs, ethers.js blockchain listener with WebSocket monitoring
  • WooCommerce: Custom PHP plugin, one-click install, checkout hooks integration
  • Shopify: Webhook architecture, Admin API integration for payment links
  • MNEE Integration: ERC-20 contract interactions, Transfer event monitoring, test faucet for developers

Accomplishments that we're proud of

Fully Functional End-to-End MNEE Payments: We built a complete payment solution that actually works in production. From adding products to cart, through checkout, wallet connection, MNEE token approval, transfer, and automatic order confirmation the entire flow executes flawlessly with zero manual intervention. Watching our blockchain listener detect an MNEE transfer and update the order status in real-time validated months of architecture decisions.

First Multi-Platform MNEE Payment Gateway: Unlike existing crypto payment solutions that lock merchants into single platforms, Cartee natively supports both WooCommerce (3.9M stores) and Shopify (4.4M stores). Merchants operating multiple stores across different platforms manage everything from one unified dashboard. This multi-platform approach unlocks 8.3 million potential merchant integrations a market reach no other MNEE payment solution currently offers.

Production-Ready for MNEE Mainnet: While currently demonstrating on testnet, our architecture is production-hardened and ready for mainnet MNEE stablecoin deployment. The codebase uses TypeScript for type safety, Prisma for data integrity, and comprehensive error handling throughout. Real-time WebSocket blockchain monitoring, idempotent order updates, and transaction confirmation thresholds ensure reliability at scale.

Stablecoin Commerce Solves Volatility But Creates New UX Challenges: MNEE stablecoin eliminates cryptocurrency's biggest e-commerce barrier price volatility. But it introduces new challenges around wallet connectivity, gas fee predictability, transaction confirmation times, and blockchain literacy. We learned that successful MNEE adoption requires abstracting blockchain complexity while preserving decentralization benefits. The winning solution makes MNEE payments feel familiar to traditional shoppers while maintaining crypto's advantagese.

Following this hackathon, we're focused on transforming Cartee from a working prototype into the definitive MNEE stablecoin payment infrastructure for global e-commerce. Our roadmap addresses both technical scalability and real-world merchant adoption:

Challenges we ran into

Shopify's Closed Ecosystem: Shopify requires official Plus partnership for payment gateways. We architected a webhook-based workaround with automatic payment link injection functional but less seamless than WooCommerce.

Blockchain Event Reliability: Handling reorgs, duplicate events, failed transactions, and network instability while maintaining idempotent order updates required multiple iterations. We monitor both Transfer events and database state for accuracy.

Platform-Specific Quirks: WooCommerce's case-sensitive gateway IDs broke our settings page (hours of debugging). Shopify's Liquid email templates needed extensive cross-client testing. Each platform's unique authentication and webhooks demanded custom solution

  • Magento/Adobe Commerce: Enterprise-grade MNEE payment module for large-scale merchants

Merchant Experience & Analytics:

  • Real-Time Dashboard: Live MNEE payment volume, conversion rates, customer wallet analytics, and revenue tracking
  • Automated Refunds: One-click MNEE refund processing directly from merchant dashboard with partial refund support
  • Invoice Generation: Automatic PDF invoices for B2B MNEE payments, integrated with QuickBooks and Xero
  • Multi-Wallet Support: Let merchants use Gnosis Safe, Argent, or other smart contract wallets for enterprise treasury management

Customer Experience Optimization:

  • Mobile-First UX: Deep links for MetaMask, Trust Wallet, and Rainbow for native app payment flows on mobile
  • QR Code Payments: Generate MNEE payment QR codes for in-store/POS use cases
  • Payment Link Sharing: Shareable MNEE payment links for social commerce and messaging platforms
  • It Actually Works:** Complete end-to-end MNEE payments from cart to confirmation with zero manual intervention. Real-time blockchain listener updates orders automatically.

Multi-Platform Coverage: First MNEE gateway supporting both WooCommerce and Shopify (8.3M merchants) from one dashboard. No platform lock-in.

True Non-Custodial: Direct wallet-to-wallet MNEE transfers. We never touch funds no custody risk, KYC, or frozen accounts.

Production-Ready: TypeScript + Prisma + WebSocket monitoring = mainnet-ready architecture with comprehensive error handling.

Developer Experience: Test faucet, one-click plugin install, live demos. Other devs already using our infrastructure for MNEE testing

  • Establish relationships with regional payment processors for compliance and local market entry

Market Validation & Scale:

  • What we learned

Production blockchain integration is hard: Handling reorgs, duplicate events, network failures, and maintaining sub-second latency requires deep architecture beyond basic smart contract calls.

Platform constraints drive innovation: Shopify's restrictions forced our webhook solution which now provides more flexibility than traditional plugins.

Gas efficiency matters: Two transactions (approve + transfer) hurts UX. EIP-2612 permit() for single-transaction MNEE payments is crucial for adoption.

Developer experience drives growth: Our faucet and docs helped other devs build MNEE integrations. Removing friction is as important as core tech.

WebSockets >>> Polling: Switching from 10s polling to WebSocket monitoring cut latency 90% and costs 80%. Real-time is non-negotiabl The goal is to make Cartee the Stripe of crypto payments - simple, reliable, and trusted by merchants worldwide.

What's next for Cartee

Platform Expansion:

  • Official Shopify Plus partnership for native checkout
  • WordPress.org plugin listing for wider distribution
  • BigCommerce (60K merchants) and Magento support

Advanced Features:

  • Recurring MNEE subscriptions for SaaS/memberships
  • Real-time analytics dashboard with conversion tracking
  • One-click MNEE refunds and automated PDF invoices
  • Mobile deep links and QR code payments

Growth Targets:

  • 100 merchants processing MNEE within 6 months
  • $1M+ MNEE transaction volume year one
  • Demonstrate 2-3% cost savings vs. credit cards

Vision: Make MNEE the stablecoin of e-commerce. With 8.3M potential merchant integrations, Cartee is the infrastructure layer onboarding crypto commerce all powered by MNEE stablecoin

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