Payment Processing System

A Rust-based payment processing system built with Axum web framework, featuring async/await throughout and PostgreSQL for data persistence.

Features

• RESTful API for payment processing
• Paystack payment gateway integration
• PostgreSQL database with connection pooling
• Async/await implementation with Tokio runtime
• Modular gateway architecture for easy payment provider additions

Prerequisites

• Rust (latest stable version)
• PostgreSQL database
• Environment variables configured (see Configuration section)

Quick Start

1. Clone and setup

   git clone https://github.com/BiliqisO/payment-processing-system.git
   cd payment-processing-system

2. Configure environment Create a .env file with:

   DATABASE_URL=postgresql://username:password@localhost/dbname
   PAYSTACK_SECRET_KEY=your_paystack_secret_key
   

3. Build and run

   cargo build
   cargo run

The server will start on localhost:3000.

Development Commands

Building and Running

cargo build          # Build the project
cargo run            # Run the application
cargo check          # Check code without building
cargo run --release  # Run with optimizations

Code Quality

cargo fmt      # Format code
cargo clippy   # Run linter
cargo test     # Run tests

API Endpoints

Payment Processing

• POST /pay - Initialize payment transaction

  {
    "user_id": "uuid",
    "email": "string",
    "amount": number
  }

Architecture

Core Structure

• API Layer (src/api/): Axum HTTP handlers and routing
• Database Layer (src/db/): SQLx models and schema definitions
• Services Layer (src/services/): Business logic and payment gateway integrations
• Configuration (src/config.rs): Environment-based app configuration

Database Models

• User: UUID, email, timestamps
• Wallet: User balance and currency tracking
• Transaction: Payment records with gateway references

Payment Gateways

• Paystack: Fully implemented with amount conversion (Naira to Kobo)
• Modular design allows easy addition of new payment providers

Configuration

Required environment variables:

• DATABASE_URL: PostgreSQL connection string
• PAYSTACK_SECRET_KEY: Paystack API secret key

Contributing

When adding new features:

1. Follow existing async patterns
2. Use SQLx for database operations
3. Implement proper error handling
4. Add new payment gateways in src/services/gateways/