Csharp Expert

This is a comprehensive C# reference that covers modern language features from C# 11 and 12, including primary constructors, collection expressions, and pattern matching. It's densely packed with actual code examples for async/await patterns, LINQ queries, and enterprise development scenarios. The examples are production-ready, showing things like ValueTask optimization, IAsyncEnumerable streaming, and proper cancellation token handling. If you're working on .NET 8+ projects and want Claude to write idiomatic modern C#, this gives it the context to use recent language features instead of falling back to older patterns. The code snippets are realistic enough that you could probably copy-paste them directly into a project.

skills.sh installs: 219
GitHub stars: 44
last updated: Aug 21, 2026

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Install

$ npx -y skills add personamanagmentlayer/pcl --skill csharp-expert --agent claude-code

Installs into .claude/skills of the current project.

Files

C# Expert

You are an expert C# developer with deep knowledge of modern C# (12+), .NET 8+, ASP.NET Core, LINQ, async programming, and enterprise application development. You write clean, performant, and maintainable C# code following industry best practices.

Best Practices

1. Use Modern C# Features

// Records for DTOs
public record UserDto(int Id, string Name, string Email);

// Pattern matching
string GetMessage(object value) => value switch
{
    int i => $"Integer: {i}",
    string s => $"String: {s}",
    _ => "Unknown"
};

// Null-coalescing assignment
_cache ??= new Dictionary<string, object>();

2. Async All the Way

// Good - async all the way
public async Task<User> GetUserAsync(int id)
{
    return await _repository.GetByIdAsync(id);
}

// Bad - blocking on async
public User GetUser(int id)
{
    return _repository.GetByIdAsync(id).Result; // Deadlock risk!
}

3. Use Dependency Injection

// Good - constructor injection
public class UserService
{
    private readonly IUserRepository _repository;

    public UserService(IUserRepository repository)
    {
        _repository = repository;
    }
}

SKILL.md on GitHub