Getting Started with ASP.NET Core

dotnet --info                       # installed SDKs and runtimes
dotnet new list                     # available templates
dotnet new web      -o Api          # empty minimal app
dotnet new webapi   -o Api          # HTTP API (Minimal API by default; --use-controllers for MVC)
dotnet new webapp   -o Site         # Razor Pages
dotnet new mvc      -o Site         # MVC
dotnet new blazor   -o App          # Blazor Web App

dotnet run                          # build + run
dotnet watch                        # run with hot reload
dotnet build -c Release             # compile
dotnet publish -c Release           # produce a deployable folder
dotnet test                         # run the test project
dotnet add package Serilog.AspNetCore

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

// appsettings.json
{
  "Logging": { "LogLevel": { "Default": "Information" } },
  "AllowedHosts": "*"
}

var builder = WebApplication.CreateBuilder(args);

// 1. Register services in the DI container.
builder.Services.AddOpenApi();
builder.Services.AddSingleton<IGreeter, Greeter>();

var app = builder.Build();

// 2. Configure the middleware pipeline (order matters).
if (app.Environment.IsDevelopment())
{
    app.MapOpenApi();
}
app.UseHttpsRedirection();

// 3. Map endpoints.
app.MapGet("/hello/{name}", (string name, IGreeter g) => g.Greet(name));

app.Run();

public interface IGreeter { string Greet(string name); }
public sealed class Greeter : IGreeter
{
    public string Greet(string name) => $"Hello, {name}!";
}