1. Introduction to REST APIs and .NET 10

1.1 Introduction to REST APIs and .NET 10

• REST Principles: Resource-based URLs, stateless communication, standard HTTP methods
• What’s New in .NET 10: Performance improvements, new minimal APIs enhancements, built-in rate limiting improvements
• Why .NET for APIs: Cross-platform, high performance, mature ecosystem
• Learning Path Overview: From basic CRUD to production-ready APIs

1.2 Installing .NET 10 SDK and Tooling

• Download and install .NET 10 SDK
• Verify installation: dotnet –version
• IDE options: Visual Studio 2025, VS Code, Rider
• Essential extensions: C# Dev Kit, REST Client, Docker

1.3 Creating the Initial Web API Project

dotnet new webapi -n CommandAPI
cd CommandAPI
dotnet run

• Understanding the default template
• Project file structure walkthrough
• Code Segment: Examining CommandAPI.csproj

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net10.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>
</Project>

1.4 Understanding Program.cs (Minimal Hosting Model)

• Evolution: From Startup.cs to minimal APIs
• Program.cs anatomy:

var builder = WebApplication.CreateBuilder(args);
// Service registration happens here
builder.Services.AddControllers();

var app = builder.Build();
// Middleware pipeline configured here
app.MapControllers();
app.Run();

• Key Concepts:
  • WebApplicationBuilder - constructs the host
  • Service container - dependency injection setup
  • Middleware pipeline - request processing chain
  • Teaching Point: Show how this replaced the old Program.cs + Startup.cs pattern

1.5 Introduction to the Sample Domain

• Domain Context: Command-line reference application
• Core Entities:
  • Platform: Represents OS/environment (Windows, Linux, Docker)
  • Command: Specific command-line instruction for a platform
• Real-world Analogy: Like a cookbook (Platforms) with recipes (Commands)
• Business Rules:
  • One Platform has many Commands
  • Every Command must belong to a Platform
  • Commands are user-specific