How to Begin Using Minimal APIs in.NET Core?

Microsoft introduced Minimal APIs, a streamlined approach to creating HTTP APIs with fewer boilerplate and a greater emphasis on functionality, with the release of.NET 6. Microservices, lightweight APIs, and quick prototyping are all best served by minimal APIs.

Minimal APIs: What Are They?
Developers can design RESTful services without controllers, starting classes, or complicated configurations thanks to minimal APIs. The Program.cs file contains definitions for everything.

They are:

• Lightweight

• Fast to develop

• Easy to read

• Perfect for small to medium APIs

Why Minimal APIs?

Traditional Web APIs require:

• Controllers

• Attributes

• Dependency injection setup

• Multiple files

Minimal APIs reduce this complexity by enabling you to define endpoints directly using lambda expressions.

Benefits:

• Less boilerplate code

• Improved performance

• Easy learning curve

• Clean and concise syntax

Creating a Minimal API in .NET Core

Step 1: Create a New Project

Use the following command:

dotnet new web -n MinimalApiDemo

Plain text

Open the project in Visual Studio or VS Code.

Step 2: Program.cs Example

Here is a simple Minimal API example:

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

app.MapGet("/", () => "Welcome to Minimal API!");

app.MapGet("/hello/{name}", (string name) =>
{
    return $"Hello, {name}!";
});

app.Run();

Plain text

Step 3: Run the Application

Run the project and navigate to:

• https://localhost:5001/

• https://localhost:5001/hello/John

HTTP Methods in Minimal APIs

app.MapGet("/users", () => "Get all users");

app.MapPost("/users", (User user) => $"User {user.Name} created");

app.MapPut("/users/{id}", (int id, User user) =>
    $"User {id} updated");

app.MapDelete("/users/{id}", (int id) =>
    $"User {id} deleted");

Plain text

Model Binding Example

public record User(int Id, string Name, string Email);

Plain text

Minimal APIs automatically bind request data to models.

Dependency Injection in Minimal APIs

builder.Services.AddScoped<IUserService, UserService>();

app.MapGet("/service", (IUserService service) =>
{
    return service.GetMessage();
});

Plain text

When Should You Use Minimal APIs?

• Microservices

• Lightweight REST APIs

• Prototypes & PoCs

• Serverless applications

Not ideal for very large, complex enterprise applications

Minimal APIs vs Controller-Based APIs

Feature	Minimal APIs	Controller APIs
Boilerplate	Very Low	High
Learning Curve	Easy	Moderate
Performance	High	Good
Structure	Flat	Layered

Conclusion

A contemporary, tidy, and effective method of creating APIs in.NET is using minimal APIs. They preserve power and flexibility while lowering complexity. Minimal APIs are a great option if your application doesn't need complex architecture.