.NET Core  

Difference Between Minimal API and Controller API .NET Core

Will discuss the difference between .NET 9 Core Minimal API Controller APIs. Minimal API is a fast and lightweight API development introduced in .NET 6.0, and it is enhanced in .NET 9. Also, well-suited for lightweight services, microservices, and small APIs. Routing and [HttpGet] attributes are not there in the minimal API. More simple and Program.cs, all the logics are defined. The controller-based API is MVC (Model-View-Controller) pattern-based, also structured, and scalable. It will be suitable for large and complex applications. Logics are organized in separate controller classes.

Minimal API (.NET 9) Controller API (.NET 9)
Quick APIs, small and compact for micro services Complex APIs, larger, and enterprise apps
Lambda expressions are used and in-line based logic development Routing is based on the Attribute and Controller APIs
Dependency Injection is supported Dependency Injection is supported and more structured
Less structured for Testing & Maintainability can be handled for larger apps also Unit Testing & Maintainability is easier with the separation of concerns
Complex routing or filter options are limited Complex routing or filters are supported and structured

Will see how to create and run both a minimal API and a Controller API. First, to create the minimal API, run the following command in the command line.

dotnet new web -n MinimalApiDemo
cd MinimalApiDemo

In the program.cs file mapping the URL and function, there are no controllers and attributes; simply added routed mappings.

Minimal API Example

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

var products = new List<Product>
{
    new(1, "Laptop", 999.99m),
    new(2, "Phone", 499.99m)
};

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

app.MapGet("/products/{id}", (int id) =>
    products.FirstOrDefault(p => p.Id == id) is Product product
        ? Results.Ok(product)
        : Results.NotFound());

app.MapPost("/products", (Product product) =>
{
    products.Add(product);
    return Results.Created($"/products/{product.Id}", product);
});

app.Run();

To check the output, visit 'https://localhost:5001/product/1'.

Controller API Example

To create an MVC controller-based AP,I run the below command.

dotnet new webapi -n ControllerApiDemo
cd ControllerApiDemo

Here we will have a simple product API example, with [HttpGet] routing example given below.

using Microsoft.AspNetCore.Mvc;

[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
    private static readonly List<Product> Products = new()
    {
        new Product { Id = 1, Name = "Laptop", Price = 1200 },
        new Product { Id = 2, Name = "Smartphone", Price = 800 }
    };

    [HttpGet]
    public ActionResult<IEnumerable<Product>> GetAll()
    {
        return Ok(Products);
    }

    [HttpGet("{id}")]
    public ActionResult<Product> GetById(int id)
    {
        var product = Products.FirstOrDefault(p => p.Id == id);
        if (product == null) return NotFound();
        return Ok(product);
    }
}

To check the output, visit 'https://localhost:5001/api/products'

Membership not found