When will you use this?

You need this before writing any ASP.NET Core code — same as installing Visual Studio before opening a project.

• Every .NET backend job expects you to run dotnet new and dotnet run on day one.
• Interviewers often ask you to explain Program.cs and what Kestrel does.

Real-world: Toolliyo-style learning platform

The EdTech / LMS team building Toolliyo-style learning platform uses Introduction to ASP.NET Core to build web pages and APIs in C# instead of PHP or Node when the team standard is .NET. students and instructors never see the C# code — they just get a fast, reliable course API and lesson progress tracking.

Production-style code

// ShopNest — minimal API hello world
var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "ShopNest API is running");

app.Run();

What happens in production: In Toolliyo-style learning platform, a solid Introduction to ASP.NET Core foundation lets the team ship course API and lesson progress tracking on schedule without environment surprises.

Lesson example (start here)

Copy this smaller example first. Once it works, compare it with the real-world code above.

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

app.MapGet("/", () => "Hello, ShopNest!");
app.MapGet("/health", () => Results.Ok(new { status = "healthy" }));

app.Run();

Line-by-line walkthrough

How it works (big picture)

• CreateBuilder sets up logging, config, and Kestrel.
• MapGet maps a URL to code (Minimal API).
• The /health endpoint returns JSON — production apps use this for load balancers.
• Run() starts listening for HTTP requests.

Do this on your computer

1. Install .NET 8 SDK from https://dotnet.microsoft.com/download
2. Run dotnet --version to confirm install
3. Open a terminal and run: dotnet new web -n ShopNest.Hello
4. cd ShopNest.Hello then dotnet run
5. Open the https://localhost URL shown in the terminal
6. Add the /health endpoint from the example and test it in the browser
7. Change the Hello message, save, and run again
8. Read the real-world section and name which part of the app uses this topic.
9. Run the example locally with dotnet run and confirm the same behavior.
10. Change one value in the example (route, text, or connection string) and predict what will happen before you save.

Experiments — try changing this

• Change a string or route in the example and save — watch the browser or Swagger response update.
• Break the code on purpose (remove a semicolon), read the error message, then fix it.
• Change the URL path and update the browser address to match.

Remember

ASP.NET Core builds web apps and APIs with C# on any OS. dotnet new and dotnet run are your first commands. Requests pass through Kestrel and middleware before your code runs. ShopNest grows across all 100 lessons in this course.

Common questions