Bitcoin Lightning Network Payment Challenge

A full-stack application for Bitcoin Lightning Network payments between nodes. This project demonstrates end-to-end invoice generation, payment execution, and real-time status tracking using LND nodes within a Polar-simulated network.

📚 Documentation

For detailed information, please refer to the following guides:

• Setup & Run Guide: Detailed instructions on how to run the application.
• API Documentation: Details of all REST endpoints available in the backend.
• Architecture: In-depth look at the technology stack, system design, and database schema.

🛠 Features

• Invoice Generation: Create BOLT-11 invoices with custom amounts and memos.
• Payment Execution: Pay invoices from a different node with real-time status updates. Invoice decoding and validation is performed before payment execution.
• Transaction History: View past invoices and payments in a unified list with status updates. Transactions are persisted in the database.
• Balance Tracking: Real-time calculation of node balance based on local database records.
• Real-time updates: Frontend and Backend communicate via WebSockets to provide real-time updates on invoice and payment status.
• RESTful API: Backend server exposes a RESTful API for frontend and external applications.
• Session tokens: Backend server uses session tokens to connect to multiple LND nodes.
• Reconnection on restart: Connections to LND nodes automatically restored after server restart.
• Dockerized Stack: Easy deployment of Frontend, Backend, and PostgreSQL database with a single docker-compose command.
• Docker networking: Docker network configured to connect to LND nodes running in Polar.
• DB management: Easy access to the PostgreSQL database for monitoring and management through pgAdmin web interface.

🏗 Tech Stack

• Frontend: Typescript, React library, Next.js React framework, Untitled.ui React components.
• Backend: Typescript, Node.js runtime environment, Express web application framework.
• Database: PostgreSQL.
• Lightning Network: Simulated LND (Lightning Network Daemon) nodes via Polar.
• Code Style: ESLint code linter, Prettier code formatter, Husky for pre-commit Git hook.
• Testing: Jest unit testing framework for backend.

📋 TODOs

• Add unit tests for frontend components
• Add e2e tests for frontend components
• Better error handling
• Better consistency between API endpoints responses
• Transactions and Balance pages are updated in real-time

📷 Screenshots

Payment page

Invoice page

Transactions page

Balance page