Implement NFC Tap-to-Pay for Lightning Payments

[GhanshyamJha05]

Summary

Alby Go currently supports QR code-based Lightning payments, which are great for digital interactions but less ideal for in-person transactions (e.g., at merchants). This feature request proposes adding NFC (Near Field Communication) support to enable "tap-to-pay" functionality, allowing users to pay Lightning invoices by tapping their phone against an NFC-enabled terminal or device.

Motivation

• User Experience: Tap-to-pay makes Lightning payments as seamless as traditional contactless cards, reducing friction for everyday use and merchant adoption.
• Bitcoin Adoption: Aligns with Summer of Bitcoin goals by making Bitcoin/Lightning more accessible for real-world transactions, bridging the gap between digital and physical commerce.
• Differentiation: NFC is rare in open-source Lightning wallets, positioning Alby Go as a leader in mobile payment innovation.
• Ecosystem Impact: Enhances NWC compatibility and could inspire similar features in other Alby tools.

Proposed Implementation

1. NFC Integration:

   • Use react-native-nfc-manager to detect and read/write NFC tags containing BOLT11-encoded Lightning invoices.
   • Handle NFC events in the app (e.g., on tag discovery, parse the invoice data).

2. Payment Flow:

   • Detect NFC tap → Extract and validate invoice (amount, expiry, payee).
   • Route to existing send confirmation screen with biometric auth option.
   • Provide haptic feedback and UI updates for success/failure.
   • Add user preferences (enable/disable NFC in settings).

3. Security & Compatibility:

   • Ensure no sensitive wallet data is transmitted via NFC (only invoice details).
   • Prioritize Android support (iOS NFC is more restricted); test with common terminals/wallets.
   • Follow Lightning standards for invoice encoding/decoding.

4. UI/UX Enhancements:

   • Add NFC toggle in settings screen.
   • Update send/receive screens with NFC availability indicators.
   • Include onboarding tips (e.g., "Tap your phone to pay").

5. Testing & Documentation:

   • Unit tests for NFC parsing and invoice validation.
   • Integration tests with mock NFC hardware.
   • End-to-end tests on physical devices.
   • Update README with NFC setup instructions.

Technical Scope

• Complexity: Medium-high (hardware integration, protocol handling, UI updates).
• Dependencies: Add react-native-nfc-manager and related Expo plugins.
• Estimated Effort: 8-12 weeks for a skilled React Native developer.
• Milestones: NFC setup → Basic tap detection → Full payment flow → Testing/polish.

Acceptance Criteria

• Users can tap to pay Lightning invoices via NFC.
• Secure, reliable, and compatible with existing Alby Go features.
• Comprehensive tests and documentation.

This would be a self-contained, impactful feature that advances Alby Go's usability without disrupting core functionality. Happy to discuss implementation details or refinements!

[GhanshyamJha05]

I would like to work on this please assign it to me

[rolznz]

@GhanshyamJha05 thanks for the PR. I marked it to be reviewed for 2.1.0 CC @im-adithya

[GhanshyamJha05]

Thanks