Minimal API Demo

A simple C# .NET 8 Minimal API project demonstrating basic API endpoints with comprehensive configuration management.

Features

• Minimal API - No controllers, just endpoints defined in Program.cs
• Swagger/OpenAPI - Interactive API documentation (configurable per environment)
• Weather Forecast - Sample endpoint returning weather data
• Echo Service - POST endpoint that echoes back messages
• HTTPS Support - Configured with development certificate
• Environment-Specific Configuration - Separate settings for Development and Production
• Strongly-Typed Configuration - Type-safe configuration access
• CORS Support - Configurable cross-origin resource sharing
• Health Checks - Built-in health monitoring endpoint

Getting Started

Prerequisites

• .NET 8 SDK
• Visual Studio 2022 (optional, but recommended)

Running the Application

1. Using Visual Studio:

   • Open MinimalApiDemo.sln in Visual Studio
   • Press F5 or click the "Run" button
   • The application will automatically open Swagger UI in your browser

2. Using Command Line:

   # Development environment (default)
   dotnet run
   
   # Production environment
   dotnet run --environment Production
   
   # Custom environment
   dotnet run --environment Staging

3. Using Docker (if you have Docker installed):

   docker build -t minimal-api-demo .
   docker run -p 7000:7000 -p 7001:7001 minimal-api-demo

API Endpoints

Once running, you can access:

• Swagger UI: https://localhost:7001/swagger (or http://localhost:7000/swagger)
• Root: GET / - Returns API information and configuration
• Hello: GET /api/hello - Returns a JSON response with timestamp and environment
• Weather: GET /api/weather - Returns a 5-day weather forecast
• Echo: POST /api/echo - Echoes back the message you send
• Health: GET /health - Health check endpoint
• Config: GET /api/config - Configuration details (Development only)

Configuration Structure

The application uses a hierarchical configuration system:

Base Configuration (appsettings.json)

• Common settings shared across all environments
• Default values for logging, CORS, rate limiting, etc.

Development Configuration (appsettings.Development.json)

• Enhanced logging with Debug level
• Swagger enabled
• Detailed error messages
• Local database connection strings
• Development-specific CORS origins

Production Configuration (appsettings.Production.json)

• Optimized logging (Warning level)
• Swagger disabled for security
• HTTPS required
• Production database connection strings
• Performance optimizations
• Security hardening

Port Configuration

The application is configured to run on:

• HTTP: http://localhost:7000 (Development) / http://0.0.0.0:80 (Production)
• HTTPS: https://localhost:7001 (Development) / https://0.0.0.0:443 (Production)

HTTPS Troubleshooting

If you encounter HTTPS issues:

1. Check Development Certificate:

   dotnet dev-certs https --check

2. Trust the Development Certificate:

   dotnet dev-certs https --trust

3. Clear and Recreate Certificate (if needed):

   dotnet dev-certs https --clean
   dotnet dev-certs https --trust

4. Verify Certificate in Windows:

   • Open "Manage User Certificates" (certmgr.msc)
   • Check "Personal" → "Certificates" for "localhost" certificate

Example Usage

Get API Information

curl https://localhost:7001/

Get Weather Forecast

curl https://localhost:7001/api/weather

Echo a Message

curl -X POST https://localhost:7001/api/echo \
  -H "Content-Type: application/json" \
  -d '{"message": "Hello, Minimal API!"}'

Health Check

curl https://localhost:7001/health

Configuration (Development only)

curl https://localhost:7001/api/config

Using HTTP (if HTTPS doesn't work)

curl http://localhost:7000/api/hello

Project Structure

MinimalApiDemo/
├── Program.cs                    # Main application entry point and API endpoints
├── MinimalApiDemo.csproj         # Project file with dependencies
├── appsettings.json              # Base configuration
├── appsettings.Development.json  # Development-specific configuration
├── appsettings.Production.json   # Production-specific configuration
├── Configuration/
│   └── AppSettings.cs            # Strongly-typed configuration classes
├── Properties/
│   └── launchSettings.json       # Visual Studio launch configuration
├── MinimalApiDemo.sln            # Visual Studio solution file
├── .gitignore                    # Git ignore rules
└── README.md                     # This file

Configuration Classes

The application uses strongly-typed configuration classes for better IntelliSense and type safety:

• AppSettings - Main configuration container
• ApiSettings - API metadata (name, version, description)
• CorsSettings - Cross-origin resource sharing configuration
• SwaggerSettings - OpenAPI documentation settings
• SecuritySettings - Security and HTTPS configuration
• DatabaseSettings - Database connection and options
• PerformanceSettings - Performance optimization settings

Key Features of Minimal APIs

• No Controllers - Endpoints are defined directly in Program.cs
• Top-level statements - No need for Program class or Main method
• Lambda expressions - Simple, concise endpoint definitions
• Built-in JSON serialization - Automatic serialization/deserialization
• OpenAPI support - Automatic Swagger documentation generation
• HTTPS redirection - Automatic redirection from HTTP to HTTPS
• Environment-specific configuration - Different settings per environment
• Strongly-typed configuration - Type-safe access to settings

Environment Variables

You can override configuration using environment variables:

# Set environment
set ASPNETCORE_ENVIRONMENT=Production

# Override specific settings
set ApiSettings__Name="My Custom API"
set Database__ConnectionString="your-connection-string"

Next Steps

To extend this Minimal API, consider adding:

• Database integration (Entity Framework Core)
• Authentication and authorization
• Additional API endpoints
• Custom middleware
• Logging and monitoring
• Unit tests
• Docker containerization
• CI/CD pipeline configuration