MidnightPay

Inspiration: We took inspiration for this project from our own experience as digital consultants and creators who have faced bureaucratic barriers to entry into a business. We dug deeper to see if it was just us or how many others were having similar problems. This took us to the root cause of the issue being privacy. The reason to be registered as a business is trustworthiness which then comes down to us providing private details that can validate us and therefore, our business. We started finding that an increase in creators has caused a shift in how business is done that the traditional business/financial world is not ready for. And that is where we saw the opportunity to be part of a solution to that problem with a payment platform that will guarantee privacy throughout the supply chain and to all the parties involved (customers, merchants, vendors, and intermediaries).

What it does: A privacy-preserving payment gateway platform on the Midnight Network that enables

merchants to create subscriptions and customers to pay with spending limits - all without revealing sensitive financial data.

How we built it

1. Fixed the Smart Contract Integration
   • Resolved merchant registration persistence issues
   • Fixed TypeScript compilation errors in the API layer
   • Implemented proper state management between blockchain and UI
2. Built the Merchant Dashboard
   • Created full merchant interface with business stats, earnings, and subscription management
   • Implemented subscription creation flow that generates unique subscription IDs
   • Added transaction history and active subscription tracking
   • Built withdrawal functionality with wallet signature requirements
3. Built the Customer Wallet
   • Developed customer interface with balance and subscription management
   • Implemented "Subscribe to Merchant" using subscription IDs (platform model, not marketplace)
   • Added spending limit authorization matching the smart contract design
   • Created deposit/withdrawal flows with proper wallet integration
4. Implemented Gateway Architecture
   • Built gateway selection as the entry point to the platform
   • Added role-based access (Merchant vs Customer)
   • Created gateway connection flow with proper contract initialization
5. Added Privacy Features
   • Implemented spending thresholds that customers control
   • Ensured merchants and customers don't see each other's private data
   • Added ZK-proof indicators throughout the UI

Key Technical Achievements:

• Platform Architecture: Merchants create subscription IDs, customers use them to subscribe
• Smart Contract Integration: Connected UI to Midnight Network payment contracts
• Privacy-First Design: Spending limits and data isolation between parties
• Professional UI: Complete dashboard with real-time updates and transaction management

Challenges we ran into: Our biggest challenge has been time because we had a very ambitious plan/idea and only a weekend to implement the functions we had in mind. We are a team of two people and only one developer.

Blockchain State Synchronization - Private state wasn't persisting between merchant registration and dashboard - SessionStorage and localStorage conflicts causing merchant ID mismatches - Fixed by implementing proper state management and verification flows

Accomplishments that we're proud of: Nayeli is proud of the presentation aesthetics. Built from concept to functional demo in less than 2 days. First hackathon for Nayeli!

What we learned: Nayeli learned to use 11Labs and integrate that with Powerpoint in a very short period of time. Norman .

What's next for MidnightPay: The next steps for MidnightPay would be to integrate direct pay, and high-privacy verticals like healthcare providers, legal services, and mental health services. The third phase would be to integrate e-commerce stores seeking differentiation, subscription services competing with established players, and international merchants avoiding currency controls.

Built With

• node.js
• react
• typescript
• vite