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/aspnet-core

@c207989 official
by openaiopenai/skills28k stars
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Build, review, refactor, or architect ASP.NET Core web applications using current official guidance for .NET web development. Use when working on Blazor Web Apps, Razor Pages, MVC, Minimal APIs, controller-based Web APIs, SignalR, gRPC, middleware, dependency injection, configuration, authentication, authorization, testing, performance, deployment, or ASP.NET Core upgrades.

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referencesversioning-and-upgrades.md

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Versioning And Upgrades

Primary docs:

Versioning Default

  • For new production apps in March 2026, prefer net10.0
  • For existing apps, match the repository's target framework unless the task is explicitly an upgrade
  • Before using a new API, confirm it exists in the target framework

Upgrade Workflow

  1. Identify the current target framework and SDK
  2. Read the "What's new" and breaking-changes pages for each version hop
  3. Compile and resolve obsoletions intentionally
  4. Re-run integration tests and auth flows
  5. Re-test deployment-specific behavior such as proxies, cookies, and static assets

High-Value Breaking-Change Checks

When moving to ASP.NET Core 10, watch for:

  • cookie login redirects disabled for known API endpoints
  • WithOpenApi deprecation
  • WebHostBuilder, IWebHost, and WebHost obsolescence
  • Razor runtime compilation obsolescence

When moving to ASP.NET Core 9, watch for:

  • ValidateOnBuild and ValidateScopes enabled in development when using HostBuilder
  • middleware constructor expectations and DI validation changes

When moving to ASP.NET Core 8, watch for:

  • Minimal API IFormFile antiforgery requirements
  • AddRateLimiter() and AddHttpLogging() requirements when corresponding middleware is used

Migration Principles

  • Prefer migration to the modern hosting model when touching startup extensively
  • Remove compatibility shims only after tests confirm behavior
  • Avoid mixing new framework idioms with old startup architecture in a half-migrated state
  • Keep one authoritative target framework in project files unless multi-targeting is deliberate

Preview Feature Rule

Do not introduce preview-only APIs or docs guidance unless the user explicitly asks for preview adoption or the repository is already on preview SDKs.

Source: SKILL.md on GitHub

Third-party checks

1 warning16d5 checks · Risk SAFE
  • Gen Agent Trust Hub16d

    This skill provides a comprehensive set of guidelines and reference materials for ASP.NET Core development, emphasizing security best practices and official architectural patterns. It does not contain any malicious patterns or unauthorized operations.

  • Socket16d

    No alerts

  • Snyk16d

    Risk: LOW · No issues

  • Runlayer7mo

    6/16 files flagged

  • ZeroLeaks5mo

    Score: 93/100 · 2 sections analyzed

Provenance

Signed by skilld at c207989. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub 2 months ago.

Activeupdated 7 months ago

Topics

  • Testing
  • aspnet-core
  • dotnet
  • csharp
  • blazor
  • razor-pages
  • mvc
  • minimal-apis
  • ef-core
  • signalr
  • grpc
  • authentication

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What it does

Instructs Claude on ASP.NET Core application models (Blazor Web Apps, Razor Pages, MVC, Minimal APIs), host and pipeline setup, dependency injection, configuration, authentication, testing, and deployment using current Microsoft documentation. Use for building or refactoring .NET web applications and deciding between framework patterns.

Generated from the current SKILL.md.

Frequently asked

Does this skill cover Blazor, Razor Pages, MVC, and Minimal APIs?
Yes. The skill includes dedicated references for each application model (Blazor Web Apps, Razor Pages, MVC, and Minimal/controller-based APIs) and guides you to load only the one you need for your task.
What .NET versions does this skill target?
The skill defaults to .NET 10 / ASP.NET Core 10 for new production work as of March 2026, but adapts to older pinned versions and handles migrations between major versions via the versioning-and-upgrades reference.
Does this skill use third-party libraries or stick to built-in ASP.NET Core features?
The skill prefers built-in features (DI, options, logging, ProblemDetails, OpenAPI, health checks, rate limiting, Identity) before introducing third-party infrastructure.
Can this skill help with authentication, authorization, and data access?
Yes. Cross-cutting references cover security/identity, EF Core, DbContext, and state management, loaded on-demand based on your specific task.
Does this skill guide upgrades from older ASP.NET Core versions?
Yes. The versioning-and-upgrades reference specifically handles breaking changes, obsolete APIs, and migrations between major versions.

Generated from the current SKILL.md. These answers refresh after source changes.