aspnet-core

Guidance for building, reviewing, refactoring, and architecting ASP.NET Core web applications using current official Microsoft guidance. It covers the major application models and platform areas including Blazor Web Apps, Razor Pages, MVC, Minimal APIs, controller-based Web APIs, SignalR, gRPC, middleware, dependency injection, configuration, authentication and authorization, testing, performance, deployment, and version upgrades. The central aim is to choose the right application model, compose the host and request pipeline correctly, and implement features in the style Microsoft documents today.

The skill is reference-driven and deliberately conservative about how much it loads at once, instructing the model to open only the smallest set of references that fits the task. A defined workflow starts by confirming the target framework, SDK, and current app model, then opens stack-selection.md for new apps or major refactors, program-and-pipeline.md for Program.cs and pipeline concerns, exactly one primary app-model reference (Blazor, Razor Pages, MVC, or Minimal APIs and controllers), and cross-cutting references for data and state, security and identity, real-time and background work, and testing, performance, and operations as needed. A versioning-and-upgrades reference and a source-map that ties tasks back to Microsoft Learn sections round out the set.

Default operating assumptions favor the latest stable platform unless the repository or user pins an older target; as of March 2026 the skill prefers .NET 10 and ASP.NET Core 10 for new production work and treats ASP.NET Core 11 as preview unless preview features are explicitly requested. It prefers WebApplicationBuilder and WebApplication over older Startup and WebHost patterns, favors built-in DI, options and configuration, logging, ProblemDetails, OpenAPI, health checks, rate limiting, output caching, and Identity before reaching for third-party infrastructure, and respects an existing app model rather than rewriting it. New code is expected to start from the correct dotnet new template and keep the generated structure recognizable, and any claim about the latest features should be verified against Microsoft Learn rather than memory.