Aspnet Core

Default Operating Assumptions

• Prefer the latest stable ASP.NET Core and .NET unless the repository or user request pins an older target.
• As of March 2026, prefer .NET 10 / ASP.NET Core 10 for new production work. Treat ASP.NET Core 11 as preview unless the user explicitly asks for preview features.
• Prefer WebApplicationBuilder and WebApplication. Avoid older Startup and WebHost patterns unless the codebase already uses them or the task is migration.
• Prefer built-in DI, options/configuration, logging, ProblemDetails, OpenAPI, health checks, rate limiting, output caching, and Identity before adding third-party infrastructure.
• Keep feature slices cohesive so the page, component, endpoint, controller, validation, service, data access, and tests are easy to trace.
• Respect the existing app model. Do not rewrite Razor Pages to MVC or controllers to Minimal APIs without a clear reason.

Reference Guide

• references/_sections.md: Quick index and reading order.
• references/stack-selection.md: Choose the right ASP.NET Core application model and template.
• references/program-and-pipeline.md: Structure Program.cs, services, middleware, routing, configuration, logging, and static assets.
• references/ui-blazor.md: Build Blazor Web Apps, choose render modes, and use components, forms, and JS interop correctly.
• references/ui-razor-pages.md: Build page-focused server-rendered apps with handlers, model binding, and conventions.
• references/ui-mvc.md: Build controller/view applications with clear separation of concerns.
• references/apis-minimal-and-controllers.md: Build HTTP APIs with Minimal APIs or controllers, including validation and response patterns.
• references/data-state-and-services.md: Use EF Core, DbContext, options, IHttpClientFactory, session, temp data, and app state responsibly.
• references/security-and-identity.md: Apply authentication, authorization, Identity, secrets, data protection, CORS, CSRF, and HTTPS guidance.
• references/realtime-grpc-and-background-work.md: Use SignalR, gRPC, and hosted services.
• references/testing-performance-and-operations.md: Add integration tests, browser tests, caching, compression, health checks, rate limits, and deployment concerns.
• references/versioning-and-upgrades.md: Handle target frameworks, breaking changes, obsolete APIs, and migrations.
• references/source-map.md: Map the official ASP.NET Core documentation tree to the references in this skill.

Execution Notes

• When generating new code, start from the correct dotnet new template and keep the generated structure recognizable.
• When editing an existing solution, follow the solution's conventions first and use these references to avoid framework misuse or outdated patterns.
• When a task mentions "latest", verify the feature on Microsoft Learn or the ASP.NET Core docs repo before relying on memory.