Best of ASP.NET Core — November 2025

  1. 1
    Article
    Avatar of auth0Auth0·27w

    .NET 10: What’s New for Authentication and Authorization

    .NET 10 introduces significant authentication and authorization improvements including built-in passkey support in ASP.NET Core Identity for phishing-resistant authentication, C# 14 extension members that simplify claims management with cleaner syntax, new observability metrics for tracking authentication events and performance, and a breaking change where API endpoints now correctly return 401/403 status codes instead of redirecting to login pages. The release also includes enhanced documentation for securing Blazor Web Apps with OpenID Connect.

  2. 2
    Article
    Avatar of devblogsDevBlogs·27w

    OpenAPI.NET: The Biggest Update Ever

    Microsoft released OpenAPI.NET v2 and v3, the library's biggest updates since 2018. Version 2 adds OpenAPI 3.1 support with 50% faster parsing and 35% less memory usage through System.Text.Json integration. Version 3 introduces OpenAPI 3.2 support with enhanced media types, hierarchical tags, and extended parameter options. These updates impact major .NET tools like Swashbuckle, NSwag, and ASP.NET Core's native OpenAPI support in .NET 10.

  3. 3
    Article
    Avatar of collectionsCollections·27w

    Introducing Visual Studio 2026 and .NET 10 LTS: A Leap Forward in Development

    .NET 10 brings major performance and productivity improvements, with Blazor achieving 76% faster loading times through optimized script delivery and 20% faster component rendering. Visual Studio 2026 introduces AI-native capabilities with GitHub Copilot integration, 50% faster solution loading, and adaptive debugging tools. The release includes built-in passkey authentication, declarative state persistence, 10x faster hot reload for large apps, and full C# 14 support with over 5,000 bug fixes implemented from community feedback.

  4. 4
    Video
    Avatar of nickchapsasNick Chapsas·28w

    Big Breaking Changes in .NET 10

    .NET 10 introduces several breaking changes developers should be aware of before upgrading. The IWebHost interface is now obsolete in favor of IHost, and projects should use WebApplication.CreateBuilder instead of WebHostBuilder. The new 'field' keyword can conflict with existing backing fields named 'field', requiring explicit 'this.field' or '@field' syntax. NuGet restore now audits transitive packages by default, which may fail builds when treating warnings as errors. System.Linq.Async is now built into the framework, eliminating the need for the separate NuGet package but potentially causing ambiguity in existing projects. Additional changes include implicit conversions for Span<T> and ReadOnlySpan<T>, and the new .slnx solution format.

  5. 5
    Article
    Avatar of syncfusionSyncfusion·25w

    What’s New in ASP.NET Core 10 for .NET 10: Key Features and Enhancements

    ASP.NET Core 10 introduces significant improvements across Blazor, Minimal APIs, and OpenAPI. Blazor gains automatic asset fingerprinting, reconnection UI with state persistence via the [PersistentState] attribute, and enhanced JavaScript interop with async methods and cancellation token support. Minimal APIs now include built-in validation using DataAnnotations, Server-Sent Events support for real-time streaming, and improved form binding that maps empty strings to null for nullable types. OpenAPI 3.1 compliance brings YAML support, XML comment integration, and refined schema handling. Performance enhancements include new metrics for Blazor circuits, WebAssembly profiling tools, and faster startup times through preloaded assets.

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