Reqres API Integration (.NET 7 - Clean Architecture)

This project is a .NET 7 class library and console application that demonstrates integration with the public Reqres API to fetch user information using HttpClient, with support for Clean Architecture, in-memory caching, error handling, retry logic, and the Options pattern.

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🚀 Features

• 🔌 API Client using HttpClient with IHttpClientFactory
• 📦 Strongly typed models (DTOs) with JSON mapping
• 🧱 Clean Architecture structure (Domain, Application, Infrastructure, Presentation)
• ♻️ In-Memory Caching with configurable expiration
• 🔁 Retry logic for transient failures using Polly
• ⚙️ Options Pattern to configure base URL and headers
• 🧪 Unit Tests for services
• 📺 Console App demonstrating usage

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📂 Project Structure

/src
│
├── Domain/                  
├── Application/             
├── Infrastructure/         
├── Presentation/            
└── Tests/                   

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⚙️ Configuration

appsettings.json or options pattern is used to configure:

{
  "ReqresApiOptions": {
    "BaseUrl": "https://reqres.in/api/",
    "ApiKey": "reqres-free-v1",
    "CacheDurationInMinutes": 5
  }
}

Registered via:

services.Configure<ReqresApiOptions>(configuration.GetSection("ReqresApiOptions"));
services.AddHttpClient<IUserService, ExternalUserService>()
        .AddPolicyHandler(...) // Polly retry logic

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💠 How to Run

1. Clone the repository

git clone https://github.com/your-username/reqres-api-integration.git
cd reqres-api-integration

2. Build the project

dotnet build

3. Run the console application

dotnet run --project src/Presentation

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🧪 How to Test

Run unit tests from the test project:

dotnet test

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💡 Example Usage

var user = await _userService.GetUserByIdAsync(2);
Console.WriteLine($"{user.FirstName} {user.LastName} - {user.Email}");

var allUsers = await _userService.GetAllUsersAsync();

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🧠 Design Decisions

• Clean Architecture: Separation of concerns between layers improves maintainability and testability.
• Polly: To handle transient faults like network issues.
• IMemoryCache: Improves performance by reducing repeated API calls.
• Options Pattern: Allows flexible configuration of API endpoints and settings.

📸 Screenshots

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📄 License

MIT License