What is Minimal API in .NET Core and How to Create this step by step

 Minimal API is a lightweight way to build HTTP APIs in .NET (introduced in .NET 6).

It allows you to create REST APIs with less code, without Controllers, Startup class, or complex structure.

👉 Best for:

• Microservices

• Small REST APIs

• Backend for Angular/React apps

🔥 Traditional API vs Minimal API

Traditional ASP.NET Core Minimal API

Uses Controllers No Controllers

Uses Startup.cs No Startup.cs

More boilerplate code Very less code

Better for large apps Best for small/medium APIs

Step by step implementation:

1) Create .NET Core API based Project

2)  Go into Porgram.cs

3) Write only this code

var builder = WebApplication.CreateBuilder(args);

var app = builder.Build();

app.MapGet("/", () => "Hello World!");

app.Run();

4) run

Step by step CRUD Operation

Install Swagger  Package Swashbuckle.AspNetCore

var builder = WebApplication.CreateBuilder(args);

var app = builder.Build();

List<Student> students = new()

{

    new Student(1, "Shiva", 22),

    new Student(2, "Rahul", 23)

};

// GET all students

app.MapGet("/students", () => students);

// GET by ID

app.MapGet("/students/{id}", (int id) =>

{

    var student = students.FirstOrDefault(s => s.Id == id);

    return student is not null ? Results.Ok(student) : Results.NotFound();

});

// POST

app.MapPost("/students", (Student student) =>

{

    students.Add(student);

    return Results.Created($"/students/{student.Id}", student);

});

// PUT

app.MapPut("/students/{id}", (int id, Student updatedStudent) =>

{

    var student = students.FirstOrDefault(s => s.Id == id);

    if (student is null)

        return Results.NotFound();

    students.Remove(student);

    students.Add(updatedStudent);

    return Results.Ok(updatedStudent);

});

// DELETE

app.MapDelete("/students/{id}", (int id) =>

{

    var student = students.FirstOrDefault(s => s.Id == id);

    if (student is null)

        return Results.NotFound();

    students.Remove(student);

    return Results.Ok();

});

app.Run();

public record Student(int Id, string Name, int Age);