What’s New in .NET 10? A Deep Dive into AI Agent Framework, JIT Boosts, and Runtime Enhancements

Microsoft has officially released .NET 10, a major update to its development platform that promises the highest performance to date across the runtime, workloads, and language features.

AI Agent Framework

The new Microsoft Agent Framework (MAF) aims to make building intelligent AI agents as straightforward as creating a Web API. It provides a set of .NET libraries that reduce development complexity, supporting sequential, concurrent, hand‑off, and group‑chat orchestration. Agents can be defined via functions or integrated with model‑context protocols (MCP) and can be deployed using familiar .NET hosting patterns with built‑in dependency injection, middleware, and production‑ready observability.

Cryptography Extensions

.NET 10 adds a broad range of cryptographic APIs, covering encryption, globalization, numeric computing, serialization, collections, and diagnostics. It expands post‑quantum cryptography support in the Windows Cryptography API (CNG) with next‑generation algorithms such as enhanced ML‑DSA, HashML‑DSA, and composite ML‑DSA, plus AES‑KeyWrap padding for secure key‑wrapping scenarios.

Runtime and JIT Improvements

The runtime now features significant JIT enhancements: better inlining, method de‑virtualization, and stack allocation optimizations. It adds support for Intel AVX10.2, improves NativeAOT for smaller and faster pre‑compiled apps, refines struct‑parameter code generation, and introduces loop‑reversal optimizations for superior performance.

C# 14 Enhancements

C# 14 introduces field‑supported attributes, simplifying property initialization and custom accessor patterns. The new null‑conditional assignment operator ?.= reduces boilerplate, and nameof can be used without specifying generic type arguments (e.g., nameof(List<>)). Additional language refinements include static extension methods, static/instance extension properties, and support for ref and in parameters in lambda expressions.

if (user is not null) {
    user.LastActive = DateTime.UtcNow;
}

can now be written as:

user?.LastActive = DateTime.UtcNow;

F# 10 Updates

F# 10 brings language, library, and tooling enhancements that improve safety, resilience, and performance. Nullable reference types provide type‑safe interop with C# libraries, optimized integer ranges speed up loops and comprehensions, and discriminated unions now generate .Is* properties for quick case testing.

Runtime Enhancements

1) AVX10.2 Support – .NET 10 adds support for the upcoming AVX10.2 instruction set on x64 CPUs, though hardware will arrive next year.

2) Stack‑Allocated Small Arrays – Value‑type and reference‑type arrays that are short‑lived can be allocated on the stack, reducing GC pressure. Example:

static void Sum() {
    int[] numbers = {1, 2, 3};
    int sum = 0;
    for (int i = 0; i < numbers.Length; i++) {
        sum += numbers[i];
    }
    Console.WriteLine(sum);
}

Here, numbers is stack‑allocated because its lifetime ends when Sum returns.

static void Print() {
    string[] words = {"Hello", "World!"};
    foreach (var str in words) {
        Console.WriteLine(str);
    }
}

Similarly, words is stack‑allocated.

3) Garbage Collector – The generational GC continues to manage object lifetimes, with write‑barrier mechanisms to track cross‑generation references. .NET 10 includes fixes that remove certain write‑barrier overhead, improving throughput.

4) JIT Optimizations – Enhancements include better inline heuristics, improved struct member code generation, and removal of array‑enumeration abstractions.

SDK Enhancements

1) Package Reference Pruning – NuGet now automatically removes unused package references, reducing restore time and build overhead. This behavior is enabled by default for all .NET 10+ projects.

2) MSBuild Unification – Starting with .NET 10, the MSBuild executable used by Visual Studio and the dotnet CLI is a .NET‑based build, allowing the same tasks to run in both environments without duplication.

3) New CLI Commands – The dotnet tool exec command runs tools without global or local installation, useful for CI/CD pipelines. A new dnx script forwards arguments to the dotnet CLI, and the --cli-schema flag outputs a JSON tree of commands.

4) Single‑File Execution – Developers can now run a lone .cs file with dotnet run, automatically AOT‑compiling it and supporting dotnet publish without a project file.

Additional .NET 10 Features

.NET MAUI 10 introduces a new project template integrated with Aspire services, offering telemetry, service discovery, and OpenTelemetry configuration.

Core MAUI controls such as BlazorWebView and HybridWebView gain request‑interception capabilities for header modification, redirects, or local responses.

Windows Forms receives clipboard access and data‑format improvements.

ASP.NET Core 10 adds Blazor enhancements, OpenAPI upgrades, and minimal API refinements for faster web development.

Overall, .NET 10 delivers a compelling mix of performance boosts, language innovations, expanded cryptography, and developer‑friendly SDK tools, positioning it as a strong LTS release for modern application development.