.NET 9 Minimal API

Mustafa Gönültaş
Haziran 07, 2025
Türkçe Oku
This blog post details the significant performance enhancements introduced to Minimal APIs with .NET 9. Thanks to Kestrel optimizations, HTTP/3 support, reduced memory consumption, and Native AOT improvements, Minimal APIs have become incredibly fast without sacrificing simplicity. These innovations offer developers a more efficient and rapid development experience, ideal for cloud-native applications and microservices.

Unleashing Incredible Performance in Minimal APIs with .NET 9: Goals and Advantages

In the modern software landscape, performance is an indispensable factor for the success of applications. As microservices, serverless architectures, and cloud-native applications evolve, the need for lightweight, fast, and efficient APIs has grown even more. This is precisely where .NET 9 steps into the spotlight, bringing groundbreaking performance improvements, particularly in the realm of Minimal APIs.

In this blog post, we will delve into the incredible performance boost that .NET 9 brings to Minimal APIs, the purpose behind these innovations, the advantages they offer to developers and businesses, and their common use cases.

What are Minimal APIs? A Brief Overview

Introduced with ASP.NET Core 6, Minimal APIs aim to simplify the API development process by reducing the “ceremony” associated with traditional ASP.NET Core patterns like Controllers, Actions, and Startup.cs. They allow you to create HTTP API endpoints with less code, and at a faster pace. Typically defined within a single Program.cs file, they are ideal for small services or functional APIs.

The Incredible Performance Leap in Minimal APIs with .NET 9

.NET 9 has delivered a significant leap in the performance of Minimal APIs compared to previous versions. This improvement is based on several key factors:

  1. Kestrel Optimizations: Kestrel, the web server for ASP.NET Core, has been further optimized in .NET 9. This enables Minimal APIs to respond much faster, especially under high concurrent request loads. Network protocols and I/O operations have been made more efficient.

  2. HTTP/3 Support and Enhancements: Broader and more mature support for HTTP/3 enhances overall API performance by reducing latency and more efficiently managing multiple requests over the same connection.

  3. Lower Memory Consumption: Since Minimal APIs inherently contain fewer dependencies and abstractions, they consume less memory, especially when combined with general memory management improvements in .NET 9. This is crucial for intensive workloads or environments with limited resources (e.g., IoT devices, edge computing).

  4. AOT (Ahead-of-Time) Compilation and Native AOT Improvements: .NET 9 has better integrated Native AOT compilation capabilities with Minimal APIs. This allows applications to be fully compiled into machine code at build time, virtually eliminating runtime startup times and creating smaller executables. This significantly mitigates “cold start” issues, particularly in cloud and serverless environments.

  5. Reduced Overhead: The overhead introduced by traditional ASP.NET Core middlewares, filters, and model binding processes is minimal in Minimal APIs. .NET 9 further optimizes this overhead, shortening the time between request processing and response return.

Goals of These Innovations and Advantages for Developers

The primary goals behind .NET 9's focus on Minimal APIs and the advantages this brings to developers are:

  • Speed and Efficiency: The core aim is to run APIs as fast and efficiently as possible. This translates to higher request processing capacity with fewer server resources.

  • Simplicity and Rapid Development: With less boilerplate code, developers can focus more on business logic and build APIs much more quickly.

  • Optimization for Cloud-Native Applications: Minimal APIs' small memory footprint and Native AOT compatibility make them ideal for containerized applications (Docker, Kubernetes) and serverless functions (Azure Functions, AWS Lambda). Reduced “cold start” times and decreased resource consumption can lead to significant savings in cloud costs.

  • IoT and Edge Computing Support: The ability to run high-performance APIs even on devices with limited resources.

  • Broad Range of Use Cases: They have become an excellent choice for building lightweight services, microservice endpoints, API gateways, and simple HTTP handlers for the backend.

A Simple Minimal API Example

The way Minimal APIs are written remains fundamentally the same in .NET 9, but the engine behind them is much faster:

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

app.MapGet("/", () => "Hello Minimal API in .NET 9!");

app.MapGet("/products/{id}", (int id) =>
{
    // Simulation of a database query or other operation
    var product = new { Id = id, Name = $"Product {id}", Price = id * 10.0m };
    return Results.Ok(product);
});

app.Run();

This example defines two simple HTTP endpoints with just a few lines of code. With .NET 9, this snippet will run with lower resource consumption and higher performance behind the scenes.

Conclusion

With .NET 9, Minimal APIs have taken a massive leap forward in terms of performance, simplicity, and suitability for cloud-native development. With faster startup times, lower memory usage, and increased request processing capacity, they offer a powerful toolkit for developers to meet modern application needs. Especially in scenarios like microservices and serverless functions, .NET 9 Minimal APIs can elevate your application's performance and cost-efficiency to the next level.

If you are seeking speed and efficiency in your development journey, .NET 9 and Minimal APIs are definitely worth exploring!