🚀 .NET API Versioning with Scalar UI

This project demonstrates a clean implementation of API Versioning in ASP.NET Core (.NET 9) using URL-based versioning along with a modern API testing interface powered by Scalar UI.

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📌 Features

• ✅ RESTful CRUD API for managing Students
• ✅ API Versioning (V1 & V2) using URL segments
• ✅ Separate DTOs for each version
• ✅ Backward compatibility support
• ✅ Clean architecture with Service layer
• ✅ Scalar UI for interactive API testing
• ✅ Lightweight in-memory data storage

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🧱 Tech Stack

• .NET 9 / ASP.NET Core Web API
• API Versioning (Asp.Versioning)
• Scalar UI (OpenAPI-based API client)
• C#

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📂 Project Structure

Controllers/
 ├── V1/
 │    └── StudentsV1Controller.cs
 ├── V2/
 │    └── StudentsV2Controller.cs

Entities/
 ├── DTOs/
 │    ├── V1/
 │    └── V2/
 └── Models/

Services/
 ├── IStudentService.cs
 └── StudentService.cs

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🔄 API Versioning Strategy

This project uses URL-based versioning:

/api/v1/students
/api/v2/students

🔹 V1 Response

{
  "id": 1,
  "name": "John Doe"
}

🔹 V2 Response

{
  "id": 1,
  "firstName": "John",
  "lastName": "Doe"
}

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🌐 Scalar API UI

Scalar provides a modern interface to test APIs.

Access it at:

https://localhost:{port}/scalar

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▶️ Getting Started

1. Clone the repository
2. Run the project
3. Open Scalar UI
4. Test endpoints with version values

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💡 Key Learnings

• How to implement API versioning in real-world applications
• Importance of DTO separation for backward compatibility
• Clean service-based architecture
• Using modern API clients like Scalar instead of Swagger

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📌 Future Enhancements

• Integration with Entity Framework Core
• Database support (SQL Server)
• Authentication & Authorization (JWT)
• AutoMapper for DTO mapping
• Versioning via headers/query params

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🤝 Contribution

Feel free to fork and enhance this project 🚀