MNEE Receipts

More merchants want to accept blockchain payments. But there's a huge problem: friction & accounting.

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MNEE Receipts - Hackathon Submission

Inspiration

The crypto revolution is real, but it's hitting a wall: accounting friction.

I watched merchants struggle with a fundamental problem:

  • They can accept crypto payments instantly
  • But they can't track expenses or file taxes easily
  • Traditional accounting software ignores blockchain
  • Crypto tools ignore accounting

Meanwhile, I saw two powerful technologies converging:

  1. QR codes - Ubiquitous, frictionless payment initiation
  2. Blockchain - Provides immutable audit trail and instant settlement

I realized: what if I combined these to eliminate friction from crypto payments and accounting?

MNEE Receipts was born from this insight: make crypto payments as simple as scanning a QR code, and make accounting as automatic as receiving a payment.

What It Does

MNEE Receipts is a complete solution to crypto payment and accounting friction:

1. Frictionless Payment Acceptance (QR-First)

  • Merchants generate payment links in one click
  • Customers scan QR code with any wallet
  • Payment confirmed instantly on Ethereum mainnet
  • Invoice PDF generated automatically
  • Zero payment processor fees

Friction eliminated:

  • No payment forms to fill out
  • No waiting for payment confirmation
  • No manual invoice creation
  • No payment processor integration needed

2. Expense Management

  • Add and categorize expenses manually
  • Track expense history with full audit trail
  • Categories: Meals, Office Supplies, Travel, Utilities, Marketing, Other
  • All expenses stored with timestamps

Friction eliminated:

  • No scattered expense records
  • No categorization confusion
  • No lost expense data
  • Organized records for tax preparation

3. Accounting Integration (QuickBooks-Ready)

  • Transactions sync to QuickBooks automatically
  • Expenses categorized for tax reporting
  • Blockchain provides immutable audit trail
  • Ready for tax preparation
  • Compliance built-in

Friction eliminated:

  • No manual accounting entry
  • No tax preparation scramble
  • No audit trail gaps
  • No compliance uncertainty

How I Built It

Tech Stack Decisions

I chose technologies specifically to reduce friction:

Frontend: Next.js 15 + React 19

  • Fast, responsive UI for quick interactions
  • Server components for efficient data loading
  • TypeScript for type safety

Blockchain: Viem + Wagmi + RainbowKit

  • Low-level control over transactions
  • Multiple wallet support (MetaMask, WalletConnect, Coinbase Wallet)
  • Ethereum mainnet with MNEE USD Stablecoin

Database: Supabase (PostgreSQL)

  • Row-Level Security for data isolation
  • Built-in storage for invoice PDFs
  • Real-time subscriptions for live updates

Styling: Tailwind CSS + shadcn/ui

  • Rapid UI development
  • Consistent, professional design
  • Accessible components out of the box

Third-Party APIs/SDKs

Technology License Purpose
Viem MIT Ethereum blockchain interactions
Wagmi MIT React hooks for Ethereum
RainbowKit MIT Wallet connection UI
Supabase Apache 2.0 Database and storage
shadcn/ui MIT UI components
Recharts MIT Analytics charts
React PDF MIT Invoice PDF generation
QRCode.react ISC QR code generation

Architecture Highlights

Wallet-First Design

  • No passwords, just connect wallet
  • Merchant account created automatically
  • Wallet address is the unique identifier

QR-Optimized Payment Flow

Generate Link → QR Code → Customer Scans → Wallet Opens → Approve → Confirmed

Each step is one action. No forms. No friction.

Blockchain Verification

Payment Sent → Tx Hash → Blockchain Confirms → Record Created → Invoice Generated

Immutable audit trail for every transaction.

Key Implementation Details

  1. QR Code Generation

    • Dynamic QR codes for each payment link
    • Encodes merchant address + amount
    • Scannable from any wallet

  2. Transaction Tracking

    • Poll blockchain for confirmation
    • Create database record on confirmation
    • Generate invoice PDF automatically

  3. MNEE Stablecoin Integration

    • ERC-20 token on Ethereum mainnet
    • 1 MNEE = 1 USD (fully backed)
    • Contract: 0x8ccedbAe4916b79da7F3F612EfB2EB93A2bFD6cF

  4. QuickBooks Integration

    • OAuth flow ready for production
    • Automatic sync on transaction creation

Challenges I Ran Into

1. Wallet Connection Complexity

Supporting multiple wallets (MetaMask, WalletConnect, Coinbase) required careful configuration. RainbowKit simplified this significantly.

2. Transaction Confirmation UX

Users expect instant feedback, but blockchain confirmations take time. I implemented optimistic UI updates with polling for actual confirmation.

3. Invoice PDF Generation

Server-side PDF generation with React components was tricky. React-PDF provided a clean solution.

4. Database Race Conditions

Duplicate transaction prevention required careful use of database constraints and upsert operations.

Accomplishments I'm Proud Of

  • Zero-friction payment flow: Scan → Pay → Done
  • Automatic invoice generation: Every payment gets a professional PDF
  • Multi-wallet support: Works with any major Ethereum wallet
  • Clean, professional UI: Looks like a real product, not a hackathon project
  • Production-ready architecture: Could scale to thousands of merchants

What I Learned

1. Friction is Everywhere

I started thinking about payment friction. I ended up redesigning the entire accounting workflow. Friction compounds.

2. Blockchain Needs UX

Blockchain is powerful but confusing. QR codes, automatic invoices, and clear transaction status make it accessible.

3. Wallet Abstraction is Worth It

Supporting multiple wallets is complex but essential for adoption. Users should use their preferred wallet.

4. Database Constraints are Your Friend

Race conditions are subtle. Database constraints (UNIQUE, PRIMARY KEY) catch them automatically.

5. TypeScript Saves Time

I caught bugs at compile time that would have been runtime errors. TypeScript strict mode is worth it.

What's Next for MNEE Receipts

Short-Term

  • Mobile-optimized checkout experience
  • Email notifications for payments
  • Export transactions to CSV

Medium-Term

  • Full QuickBooks OAuth integration
  • Multi-currency support
  • Recurring payment links

Long-Term Vision

Make crypto accounting as simple as traditional accounting.

  • 100,000+ active merchants
  • $1B+ in annual transaction volume
  • Integrations with every major accounting system
  • Mobile apps for iOS and Android

Crypto is the future of finance. Accounting shouldn't be the bottleneck.

Why This Matters

Crypto adoption is accelerating. But merchants are hitting a wall: accounting.

MNEE Receipts removes that wall. I make it as easy to accept crypto payments as it is to accept credit cards. I make it as easy to track expenses as it is to fill out a form. I make it as easy to file taxes as it is to click a button.

This is how crypto goes mainstream. Not through hype. Through solving real problems.

I'm just getting started.

Contact & Links

Conclusion

MNEE Receipts solves a real problem for crypto merchants: accounting friction.

I combined QR codes and blockchain to create a frictionless workflow:

  1. Scan QR code → Payment confirmed
  2. Add expenses → Records organized
  3. Sync to QuickBooks → Taxes ready

This is the future of crypto accounting. Simple. Automatic. Compliant.

I'm excited to share this with the world.

Built With

  • administration
  • mnee
  • nextjs
  • receipt
  • web3
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