Minimal APIs in .NET 7

In today’s world of software development, speed and simplicity matter a lot.

Applications are getting bigger, but developers still want them to run faster and be easier to maintain.

With that in mind, Microsoft introduced Minimal APIs in .NET 6, and improved them even more in .NET 7.

Minimal APIs give developers a quick and lightweight way to build APIs without the extra setup or heavy structure of the full MVC (Model-View-Controller) framework.

In this guide, we will go step-by-step to understand:

What Minimal APIs are
Why are they useful
How to create one in .NET 7

Key features and benefits

When you should use them
How Sparkle Web can help you

What Are Minimal APIs?

Minimal APIs are a new style of building HTTP-based APIs using ASP.NET Core.

They are called "minimal" because:

They use less code
They have fewer configurations
They don’t require controllers or action methods

Everything is written in one simple file (Program.cs)

Instead of creating multiple files, routes, and controller classes, you can directly define your API endpoints in just a few lines of code.

They are perfect for:

Small services
Microservices
Serverless apps

Lightweight APIs that do not need the full MVC setup

Why Use Minimal APIs?

1. Easy to Understand

You don’t need to write long classes or set up multiple files. Just define your route and what it should return — all in one place.

2. Faster Performance

Since they remove the extra MVC components, they use less CPU and memory. This means they respond faster.

3. Less Code

You don’t have to write controllers, actions, or model binding unless you really need them. This means less typing and less chance for mistakes.

4. Quick Startup

Minimal APIs start much faster compared to traditional APIs, which is very useful in serverless and microservices, where startup time matters a lot.

How to Create a Minimal API in .NET 7

Let’s go step-by-step.

Step 1: Create the Project

Open your terminal and type:

dotnet new webapi -n MinimalApiDemo
cd MinimalApiDemo

This creates a new Web API project.

Step 2: Write Your Minimal API Code

In the Program.cs file, write this:

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

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

app.Run();

MapGet → Defines a GET API endpoint.
/ → Root route.
/greet/{name} → Route with a parameter.

Step 3: Run the Application

In your terminal:

dotnet run

Then:

Go to http://localhost:5000 → You will see "Hello, World!"
Go to http://localhost:5000/greet/John → You will see "Hello, John!"

Key Features of Minimal APIs in .NET 7

1. Less Boilerplate Code

Before:

[ApiController]
[Route("api/[controller]")]
public class GreetingController : ControllerBase
{
    [HttpGet("{name}")]
    public string GetGreeting(string name)
    {
        return $"Hello, {name}!";
    }
}

Now:

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

Much simpler!

2. No Controllers Needed

Everything is written directly in Program.cs.

3. Built-in Dependency Injection

Example:

app.MapGet("/items", async (IItemService itemService) => {
    var items = await itemService.GetItemsAsync();
    return Results.Ok(items);
});

You can still use services and repositories — the code just becomes cleaner.

4. Flexible Routing

You can easily work with:

Path parameters (/greet/{name})
Query parameters (/search?keyword=test)
Header parameters

5. Easy JSON Responses

By default, Minimal APIs return JSON without extra setup.

Performance Improvements in .NET 7

Faster Startup → Great for cloud and serverless apps.
Smarter Routing → Less processing overhead.
Better Memory Use → Uses fewer resources for small services.

When Should You Use Minimal APIs?

They are perfect for:

Small APIs or microservices
Serverless applications (like AWS Lambda or Azure Functions)
Prototypes and proof-of-concept projects

Apps that need fast startup and low memory usage

Conclusion

Minimal APIs in .NET 7 are:

Up to 30% faster at starting compared to traditional APIs (based on Microsoft’s internal tests)
Can reduce boilerplate code by 60% — more focus on actual business logic
Can lower hosting costs by up to 25% for cloud-based apps because they use fewer resources

Improve first-response latency, making your application more user-friendly

How Sparkle Web Can Help

At Sparkle Web, we:

Build fast and scalable .NET applications
Use Minimal APIs for cloud-native and microservice solutions
Optimize your application for speed, scalability, and cost savings

Help you move your existing apps to a faster, lightweight architecture

Want to speed up your .NET projects? Let’s talk about how Minimal APIs can make your work easier, faster, and more cost-effective.

Contact Us : +91 90331 80795

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