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Articles, releases and tools featured in The .NET Insider, with credit to the original authors. Browse by topic or start with the most recent picks.
Version 11.0 rebuilds the extension as one Native AOT process with cached project loading. In Microsoft's benchmark on the 407-project Aspire repo, full solution load drops from 84 s to 3 s and memory from about 2 GB to 316 MB; it's in pre-release for now.
The dashboard now keeps traces, logs and resource state after you stop the AppHost (up to 10 runs, stored locally in SQLite). You can go back to the run where a bug showed up, and the new opt-in WithRepl() opens a signed-in database shell right in the dashboard.
If you enforce trusted signers or run dotnet nuget verify with Microsoft fingerprints, installs fail with NU3034 until you add the new certificate fingerprint.
Microsoft and CopilotKit released an MIT-licensed .NET SDK for AG-UI, the open protocol for streaming agent events to user-facing apps. Any .NET service can now expose or consume agent endpoints that work with TypeScript and Python clients.
The experimental Microsoft.AspNetCore.Components.AI package renders streamed agent output, tool calls, approval prompts and shared state as Blazor components, on top of any IChatClient. Try it with the .NET 11 RC1 SDK and the AgenticUI sample.
Bring Your Own Model (preview) now runs on the new Agent (Preview), with Foundry, OpenAI, Anthropic and Ollama. The old BYOM flow is gone and Ollama models need re-adding.
MSTest 4.5 can run UWP and WinUI 3 tests on the app's real UI dispatcher, across packaged, unpackaged and AppContainer hosts. Packaged hosts need Developer Mode, so check your CI agent first.
.NET 11 adds experimental DBSC support to ASP.NET Core with one call, AddDeviceBoundSession(...). It ties a login session to a key in the device's TPM, so a stolen auth cookie stops working quickly.
The new #:ref directive lets a dotnet run app.cs program pull in a second C# file. On .NET 11 RC1 it's still behind an experimental property.
A walkthrough of spotting, inspecting and decrypting encrypted JWTs with JsonWebTokenHandler. Decryption and validation are separate steps, and any token pasted into a chat or log should be treated as exposed.
Rules written in prompts fade as an agent's context fills up, so the article moves them into the build with TreatWarningsAsErrors, analyzers, .editorconfig and Central Package Management.
An ILLink.Substitutions.xml file turns a runtime check into a constant, so the linker can remove code it couldn't prove was unused. In Andrew's case that cut a NativeAOT binary by 22 to 25 percent.
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