XRPService

Overview

XRPService is a microservice that enables XRP Ledger (XRPL) integration for EV charging payments. It provides functionality for:

• Processing real-time micropayments for EV charging sessions
• Managing XRP wallets for payment processing
• Interacting with the XRP Ledger
• Tracking payment transactions on the blockchain

Features

• Payment Processing: Process micropayments in XRP for ongoing charging sessions
• Wallet Management: Create and manage XRP wallets for users and stations
• Blockchain Integration: Connect with the XRP Ledger for transaction processing
• Transaction History: Track and retrieve payment history for users
• Distributed Tracing: OpenTelemetry integration for monitoring payment flows
• Event-Based Messaging: MassTransit integration for asynchronous processing
• Dockerization: Containerized deployment with Ubuntu-based image

Architecture

The service follows the same architectural patterns as other microservices in the system:

• OpenTelemetry: End-to-end tracing and metrics
• MassTransit: Event-based messaging
• Minimal API: Modern ASP.NET Core endpoints
• Clean Architecture: Separation of concerns into services, features, and models

Workflow Diagram

This diagram illustrates the typical payment session lifecycle involving XRPService and other components:

Getting Started

Prerequisites

• .NET 9.0 SDK
• Azure Service Bus (or local equivalent)
• XRP Ledger node access (testnet/devnet for development)

Configuration

The main configuration is in appsettings.json:

{
  "XRPLedger": {
    "DefaultNetwork": "testnet",
    "Endpoints": {
      "Mainnet": "https://xrplcluster.com",
      "Testnet": "https://s.altnet.rippletest.net:51234",
      "Devnet": "https://s.devnet.rippletest.net:51234"
    }
  }
}

Running the Service

dotnet run --project XRPService

API Endpoints

Payment Endpoints

• POST /api/payments/sessions: Initialize a payment session
• POST /api/payments/micropayments: Process a micropayment
• POST /api/payments/sessions/{id}/finalize: Finalize a payment session
• GET /api/payments/history/{userId}: Get payment history for a user
• GET /api/payments/wallets/{address}: Get wallet information

Wallet Endpoints

• POST /api/wallets: Create a new XRP wallet
• GET /api/wallets/{address}: Get wallet information
• POST /api/wallets/{address}/fund: Fund a test wallet (testnet/devnet only)

Integration

This service integrates with:

1. EVSEService: For charging session management
2. XRP Ledger: For blockchain transactions
3. Monitoring: OpenTelemetry for tracing payments

Development

Key Components

• Services:

  • IXRPLService: Interface for XRP Ledger interactions
  • IWalletService: Interface for wallet management
  • IPaymentService: Interface for payment processing

• API Endpoints:

  • PaymentsEndpoints: API endpoints for payment operations
  • WalletEndpoints: API endpoints for wallet management

• Event System:

  • EnergyUpdateEvent: Triggered when energy consumption is updated
  • PaymentConfirmedEvent: Triggered when a payment is confirmed
  • PaymentFailedEvent: Triggered when a payment fails
  • SessionFinalizedEvent: Triggered when a charging session is completed

• Consumers:

  • EnergyUpdateConsumer: Handles energy updates and triggers micropayments

Testing

Test projects are organized to mirror the service structure, focusing on:

• Unit tests for service implementations
• Integration tests for API endpoints
• Mock tests for blockchain interactions

Deployment

The service is deployed as a Docker container in Kubernetes, similar to other services in the system.

Docker Deployment

Build and run the Docker container:

# Build the Docker image
docker build -t xrpservice:latest .

# Run the container
docker run -d -p 8080:80 --name xrpservice xrpservice:latest

The service uses an Ubuntu-based container with .NET 9.0 runtime.

Learn More

• XRP Ledger Documentation
• OpenTelemetry Documentation