Hello! In this tutorial we continue build your own ASP.NET Service! Requirements IDE like Visual Studio/JetBrains Rider .NET >= 10 Base C# skill Creating controller Lets create our Controller, create file "MyController.cs" Image will like this namespace ExampleProject; public class MyController { } Let's set base configuration using Microsoft.AspNetCore.Mvc; namespace ExampleProject; [Route("[controller]")] [ApiController] public class MyController : ControllerBase { } Now let's move our endpoint here remove app.MapGet("/", () => "Hello World!"); from main file and add [HttpGet] public async Task<IActionResult> Get() { return Ok("Hello, world!"); } to our controller Now we need to add this controller to Program.cs using Scalar.AspNetCore; var builder = WebApplication.CreateBuilder(args); builder.Services.AddOpenApi(); builder.Services.AddControllers(); var app = builder.Build(); if (app.Environment.IsDevelopment()) { app.MapOpenApi(); app.MapScalarApiReference(); } app.MapControllers(); app.Run(); Now let's run! Open scalar at localhost:[your port]/scalar press "Test Request" and press "Run" And now we received "Hello, world!" from our controller We can add more endpoints like this [HttpGet("{name}")] public async Task<IActionResult> Get(string name) { var start = DateTime.Now; await Task.Delay(1000); var end = DateTime.Now; return Ok($"Hello, {name}! It took {end - start} to respond."); } In next series we learn Databases and more!!!