.NETPro #51: .NET 11 RC2, dotnetup, Microsoft Agent Framework, File-Based Apps, and More...

.NETPro #51: .NET 11 RC2, dotnetup, Microsoft Agent Framework, File-Based Apps, and More...

🌏 Actionable .NET tips, the latest updates, and community insights, all in one place

Hayden Edwards

Oct 20

.NET 11 is almost here! This week, we’re looking at Release Candidate 2, which brings another round of improvements ahead of November’s final release. Microsoft has also introduced dotnetup, a new toolchain manager designed to make installing and managing .NET SDKs and runtimes easier. Plus, we’ve got the latest October servicing updates to help keep your applications secure and up to date.

In our expert community section, we’ll catch up on how Microsoft Agent Framework has evolved since version 1.0 and explore where Durable Task can make a difference in real-world applications. You’ll also discover what’s new in Spargine 10 and learn how to improve the quality of AI-generated C# code using automated checks and coding standards.

Finally, our hands-on spotlight explores file-based apps in .NET. You’ll see how to run C# code without creating a traditional project, organize it across multiple files, and add dependencies, making it easier to build scripts, utilities, and quick prototypes.

Take a look at today’s highlights first:

➡️ Get ready for .NET 11 with the latest release candidate
➡️ Take control of your .NET toolchains with dotnetup
➡️ Explore the latest Microsoft Agent Framework updates
➡️ Make AI-generated C# code cleaner and more reliable
➡️ Build file-based .NET apps without the project setup

Keep reading, and when you’re done, drop us a note about what you enjoyed and how we can make the next edition more helpful.

Cheers!
Hayden Edwards
Editor-in-Chief

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📰 What’s Happening in .NET!

The latest .NET breakthroughs are here. Haven’t explored them yet? Dive in now!

• ➡️ Get ready for .NET 11 with the latest release candidate: .NET 11 Release Candidate 2 is here, bringing another round of improvements ahead of the November release. Highlights include faster MSBuild wildcard matching, new NuGet package age controls, improvements to F# performance, and updates across ASP.NET Core, .NET MAUI, and Windows Forms. With go-live support, you can also start using RC2 in production applications.

• ➡️ Take control of your .NET toolchains with dotnetup: Microsoft has introduced the public preview of dotnetup, a new toolchain manager that makes installing, managing, and updating .NET SDKs and runtimes easier. Designed for macOS and Linux developers, it supports side by side installations, preview and nightly builds, and updates without administrator privileges. You’ll also see how it works with global.json to keep project versions consistent.

• ➡️ Catch up on the latest .NET security and reliability fixes: Microsoft has released its October 2026 servicing updates for .NET 8, 9, and 10, alongside updates for .NET Framework. The releases include security fixes and other improvements, with updated runtimes, installers, and container images available. If you're maintaining applications on supported .NET versions, now is a good time to review the release notes and apply the relevant updates.

⏱️ Time for Some Hands-On .NET

Don’t miss this edition’s spotlight guide!

🤖 Everyone wants to ship an agent. Almost nobody wants to build the plumbing underneath it

Sometimes you just want to run a C# script or test an idea without creating an entire project. With file-based apps introduced in .NET 10 and multi-file support added in .NET 11 Preview 3, you can do exactly that. Anton Martyniuk walks you through running C# files directly, adding dependencies, and organizing code across multiple files, making .NET a more flexible option for scripting, automation, and quick prototypes.

Why it’s worth exploring

This practical guide shows you how to get started with file-based apps using dotnet run, add NuGet packages and SDKs through directives, and use #:include to split your code across multiple files. You'll also explore real-world examples, including an HTTP health-check tool and a Minimal API using EF Core and SQLite, before learning how to convert a file-based app into a full project when your needs grow.

What you need before diving in

• Basic familiarity with C# and the .NET CLI

• The .NET 11 SDK for multi-file support

• A code editor such as Visual Studio or VS Code

• Basic knowledge of ASP.NET Core and EF Core for the Minimal API example

🧑🏼‍💻 What .NET Experts Are Talking About

Inside the minds of .NET pros: Real-world experience, real insights!

• ➡️ Explore the latest Microsoft Agent Framework changes: Microsoft Agent Framework has evolved rapidly since its 1.0 release in April. Developers Digest explores the latest additions, including the Agent Harness, new workflow capabilities, hosting options, and improvements to memory and agent execution. You'll also see how the framework has matured across .NET and Python, along with practical guidance for developers migrating from AutoGen or Semantic Kernel.

• ➡️ See where Durable Task makes a real difference: Long-running workflows can become difficult to manage when processes fail, restart, or depend on external systems. Tamir Dresher explores five real-world scenarios, from invoice approvals and Azure provisioning to subscription payments and AI agents, showing where Durable Task can help and where your application still needs to handle recovery and consistency. You'll get a clearer sense of when durable execution is worth the added complexity.

• ➡️ Simplify everyday .NET development with Spargine 10: David McCarter introduces the October 2026 release of Spargine 10, his open-source library of utilities and extensions for .NET developers. The update adds new helpers for collections, asynchronous tasks, file operations, and more, alongside benchmark-driven performance improvements across 340 methods. You'll see what's changed and how these additions could help you write more efficient, reliable .NET code.

• ➡️ Make AI-generated C# code cleaner and more reliable: AI can generate C# code quickly, but getting it to follow your project's coding standards is another challenge. Anton Martyniuk explains how to use Directory.Build.props, static analyzers, and .editorconfig to enforce quality during builds, rather than relying on prompts alone. You'll also see how a dedicated AI code review skill can help catch issues before they reach human reviewers.

And That’s a Wrap 🎬

Thanks for diving in. I hope this issue sparked an idea or two that could help fuel your next big project.

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Keep learning, keep building, and we’ll see you next time!

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