NexusPOS (Enterprise Retail Core)

NexusPOS is a next-generation, Tesco-scale Point of Sale (POS) system designed for high resilience, offline-first capability, and premium user experience. Built with modern .NET technologies, it bridges the gap between physical retail hardware and enterprise microservices.

🚀 Key Features

• Thick Client Architecture: Ensures continuous operation even during internet outages using local state (SQLite/LiteDB).
• Hardware Abstraction: Decoupled interfaces for Scanners, Scales, and Printers using IScanner and IScale abstractions, enabling easy testing and hardware swapping.
• Touch-First Design: Custom WPF/Avalonia UI styled specifically for touchscreen terminals with large hit targets and high-contrast accessibility.
• Scan-as-you-shop: High-fidelity replication of modern self-checkout workflows, including "Hello" screens, weighing logic, and promotions.
• Enterprise Integration: Backend ASP.NET Core microservices handling Price Lookups, Clubcard Membership, and Payment Gateways.
• Cloud Native Orchestration: Uses .NET Aspire for seamless local development orchestration and cloud deployment.

🛠️ Tech Stack

• Frontend: WPF (.NET 10) / Avalonia
• MVVM Framework: CommunityToolkit.Mvvm
• Orchestration: .NET Aspire
• Backend: ASP.NET Core
• Database: SQLite (Local), SQL Server/PostgreSQL (Cloud)
• Testing: xUnit, Moq (Hardware Simulation)

📦 Getting Started

Prerequisites

• .NET 10 SDK
• Visual Studio 2022 (v17.13+) or VS Code
• Docker Desktop (for Aspire orchestration)

Installation

1. Clone the repository:

   git clone https://github.com/junaid109/Nexus-POS.git
   cd Nexus-POS

2. Run the application with .NET Aspire:

   dotnet run --project NexusPOS.AppHost

🏗️ Architecture

The solution follows a Clean Architecture approach:

• NexusPOS.Shell: The WPF Presentation layer (UI/ViewLogic).
• NexusPOS.Application: Core business, interfaces, and use cases.
• NexusPOS.Domain: Enterprise entities (Product, Basket, promotion).
• NexusPOS.Infrastructure: External concerns (Hardware drivers, API clients, Database access).
• NexusPOS.ServiceDefaults: Shared resilience, health checks, and OpenTelemetry configuration.

🤝 Contributing

1. Fork the project.
2. Create your feature branch (git checkout -b feature/AmazingFeature).
3. Commit your changes (git commit -m 'Add some AmazingFeature').
4. Push to the branch (git push origin feature/AmazingFeature).
5. Open a Pull Request.

📄 License

Distributed under the MIT License. See LICENSE for more information.

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Built with ❤️ for the future of retail.