csharp-developer
Use when building C# applications with .NET 8+, ASP.NET Core APIs, or Blazor web apps. Builds REST APIs using minimal or controller-based routing, configures database access with Entity Framework Core, implements async patterns and cancellation, structures applications with CQRS via MediatR, and scaffolds Blazor components with state management. Invoke for C#, .NET, ASP.NET Core, Blazor, Entity Framework, EF Core, Minimal API, MAUI, SignalR.
npx skills add Jeffallan/claude-skills --skill csharp-developer --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# C# Developer Senior C# developer with mastery of .NET 8+ and Microsoft ecosystem. Specializes in high-performance web APIs, cloud-native solutions, and modern C# language features. ## When to Use This Skill - Building ASP.NET Core APIs (Minimal or Controller-based) - Implementing Entity Framework Core data access - Creating Blazor web applications (Server/WASM) - Optimizing .NET performance with Span<T>, Memory<T> - Implementing CQRS with MediatR - Setting up authentication/authorization ## Core Workflow 1. **Analyze solution** — Review .csproj files, NuGet packages, architecture 2. **Design models** — Create domain models, DTOs, validation 3. **Implement** — Write endpoints, repositories, services with DI 4. **Optimize** — Apply async patterns, caching, performance tuning 5. **Test** — Write xUnit tests with TestServer; verify 80%+ coverage > **EF Core checkpoint (after step 3):** Run `dotnet ef migrations add <Name>` and review the generated migration file before applying. Confirm no unintended table/column drops. Roll back with `dotnet ef migrations remove` if needed. ## Reference Guide Load detailed guidance based on context: | Topic | Reference | Load When | |-------|-------
- When to Use This Skill
- Core Workflow
- Reference Guide
- Constraints
- MUST DO
- MUST NOT DO
- Output Templates
- Example: Minimal API Endpoint
- Knowledge Reference
What does the csharp-developer skill do?
Use when building C# applications with .NET 8+, ASP.NET Core APIs, or Blazor web apps. Builds REST APIs using minimal or controller-based routing, configures database access with Entity Framework Core, implements async patterns and cancellation, structures applications with CQRS via MediatR, and scaffolds Blazor components with state management. Invoke for C#, .NET, ASP.NET Core, Blazor, Entity Framework, EF Core, Minimal API, MAUI, SignalR.
How do I install it?
Run `npx skills add Jeffallan/claude-skills --skill csharp-developer --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From Jeffallan/claude-skills, a repository with 10,871 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.