Getting Started With Minimal API In .NET Core API

Introduction

In this article, we will talk about the new feature introduced in .NET Core 6.0, i.e., minimal APIs (API without using controllers).

It will cover the following topics:

• What is Minimal API?
• The history of Minimal API
• Hands-on Lab – Create a .NET Core API project and Implement Minimal API

What is Minimal API?

• Minimal APIs are used to create HTTP APIs with minimal dependencies.
• They are ideal for microservices and apps that want to include only minimum files, features, and dependencies in ASP.NET Core.
• This tutorial teaches the basics of building a minimal web API with ASP.NET Core.

History of Minimal API

• The story of the minimal API started in November 2019. The developer community saw the implementation of the distributed calculator in Go, Python, C#, and Javascript.
• When the community began comparing how many files and lines of code were needed to do almost the same thing with C# compared to other languages, it was apparent that C# seemed more complicated than the rest of them.
• Imagine the number of concepts and features accumulated over the years and how overwhelming it might be for a newcomer to dig into the world of .NET web development. Therefore, a .NET Core team wanted to reduce the complexity for all developers (newcomers and veterans) and embrace minimalism. So, if we’re going to create a simple API with a single endpoint, we should be able to do it within a single file. But, if we need to switch later to using controllers again, we should also be able to do that.

Hands-on Lab – Create a .NET Core API project and Implement Minimal API

Steps to be followed:

• Open VS 2022 and create a project.
• Choose ASP.NET Core API as a template and create a directory.

• Uncheck the use controllers options from the below image to use minimal APIs.

• Open the program.cs file and see that, in case of actions in the controller, there is already a method with the route and return attributes.

• Execute the application (Press F5) and open the swapper explorer. Execute the API and see the response.

• Now, we will create a few end-points to POST and GET the data from the entity to-do within the program.cs file, without using controller and actions and return the list the data.
• Search and add the Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore package.
• Create a new class using DBContext and store the data there using POST. Call and extract the data using the GET call.

• Add the following line to use the in-memory database using EFCore.

• Create a POST API to insert data into the TODO class object. This will be in-memory.

• Execute the application (Press F5) and open the swapper explorer. Execute the todolist POST API by passing the below data.

• Create a GET API to get all the data stored in the TODO class object, which is in-memory.

• Execute the application (Press F5) and open the swapper explorer. Execute the todolist GET API to get all the details stored in TODO object in-memory.

In this article, we talked about an overview of minimal API along with a couple of POST and operations used in memory to get a hang of it.

I've attached the source code as well, for reference.

I hope you see you guys again soon.

Happy learning!