microsoft-extensions
This skill guides correct implementation of the Microsoft.Extensions stack in .NET applications, covering dependency injection, configuration, logging, options patterns, and Generic Host setup. Use it when wiring dependency injection containers, adding structured configuration and logging to non-web applications, establishing Generic Host patterns, or refactoring service registration and HTTP client usage to follow .NET platform conventions.
git clone --depth 1 https://github.com/managedcode/dotnet-skills /tmp/microsoft-extensions && cp -r /tmp/microsoft-extensions/catalog/Libraries/Microsoft-Extensions/skills/microsoft-extensions ~/.claude/skills/microsoft-extensionsSKILL.md
# Microsoft.Extensions for .NET ## Trigger On - wiring dependency injection, configuration, logging, or options - introducing Generic Host patterns into non-web .NET apps - cleaning up service registration, typed HTTP clients, or shared infrastructure code ## Workflow 1. Prefer the Generic Host for apps that need configuration, DI, logging, hosted services, or coordinated startup. 2. Keep service registration predictable: composition at the edge, concrete implementations hidden behind interfaces only where that abstraction buys flexibility. 3. Use options binding for structured configuration and validate configuration at startup when bad settings would fail later at runtime. 4. Prefer `IHttpClientFactory` and typed or named clients for outbound HTTP instead of ad-hoc singleton or per-call `HttpClient` usage. 5. Use logging categories and config-driven log levels rather than scattered ad-hoc logging behavior. 6. Avoid building mini-frameworks over Microsoft.Extensions unless the repo genuinely needs reusable composition primitives. ## Deliver - clean host wiring and service registration - configuration and logging that are observable and testable - infrastructure code that fits naturally with the .NET stack ## Validate - service lifetimes are correct - configuration is strongly typed where it matters - host setup remains easy to debug and reason about ## References - [patterns.md](references/patterns.md) - DI patterns, Configuration patterns, Options pattern, Logging patterns, HttpClientFactory patterns, Hosted Service patterns - [anti-patterns.md](references/anti-patterns.md) - Common mistakes with DI, configuration, options, logging, HttpClient, and hosted services
Build, debug, modernize, or review ASP.NET Core applications with correct hosting, middleware, security, configuration, logging, and deployment patterns on current .NET. USE FOR: working on ASP.NET Core apps, services, or middleware; changing auth, routing, configuration, hosting, or deployment behavior; deciding between ASP.NET Core sub-stacks. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Build, upgrade, and operate .NET Aspire 13.3.x application hosts with current CLI, AppHost, ServiceDefaults, integrations, dashboard, testing, and Azure deployment patterns for distributed apps. USE FOR: Aspire.AppHost.Sdk, Aspire.Hosting.*, DistributedApplication.CreateBuilder, WithReference, WaitFor, AddProject, AddRedis, AddPostgres, aspire run, aspire init, aspire. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Build, review, or migrate Azure Functions in .NET with correct execution model, isolated worker setup, bindings, DI, and Durable Functions patterns. USE FOR: working on Azure Functions in .NET; migrating from the in-process model to the isolated worker model; adding Durable Functions, bindings, or host configuration. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Build and review Blazor applications across server, WebAssembly, web app, and hybrid scenarios with correct component design, state flow, rendering, and hosting choices. USE FOR: building interactive web UIs with C# instead of JavaScript; choosing between Server, WebAssembly, or Auto render modes; designing component hierarchies and state. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Maintain or migrate EF6-based applications with realistic guidance on what to keep, what to modernize, and when EF Core is or is not the right next step. USE FOR: EF6 codebases; runtime versus ORM migration decisions; EDMX, code-first, ObjectContext, and legacy data-access review. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Design, tune, or review EF Core data access with proper modeling, migrations, query translation, performance, and lifetime management for modern .NET applications. USE FOR: DbContext, migrations, model configuration, EF queries, tracking, loading, performance, transactions, and EF6 migration decisions. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Build, review, or migrate .NET MAUI applications across Android, iOS, macOS, and Windows with correct cross-platform UI, platform integration, and native packaging assumptions. USE FOR: working on cross-platform mobile or desktop UI in .NET MAUI; integrating device capabilities, navigation, or platform-specific code; migrating Xamarin.Forms or aligning. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.
Use ML.NET to train, evaluate, or integrate machine-learning models into .NET applications with realistic data preparation, inference, and deployment expectations. USE FOR: ML.NET integration; local model training or retraining; inference pipelines, model loading, evaluation, and deployment review. DO NOT USE FOR: unrelated stacks; generic tasks that do not need this specific guidance. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.