Csharp Async

A solid code reviewer for async C# that catches the stuff that actually matters. It'll flag when you're mixing .Wait() with async code, remind you about ConfigureAwait(false) in library scenarios, and push you toward Task.WhenAll() instead of sequential awaits. The skill knows the difference between when to use ValueTask versus Task, and it won't let you get away with async void methods outside event handlers. Good for both fixing existing async code that's causing deadlocks and writing new async methods that follow TAP patterns correctly.

skills.sh installs: 11.1K
GitHub stars: 41K
last updated: Aug 21, 2026

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Install

$ npx -y skills add github/awesome-copilot --skill csharp-async --agent claude-code

Installs into .claude/skills of the current project.

Files

C# Async Programming Best Practices

Your goal is to help me follow best practices for asynchronous programming in C#.

Naming Conventions

Use the 'Async' suffix for all async methods
Match method names with their synchronous counterparts when applicable (e.g., GetDataAsync() for GetData())

Return Types

Return Task<T> when the method returns a value
Return Task when the method doesn't return a value
Consider ValueTask<T> for high-performance scenarios to reduce allocations
Avoid returning void for async methods except for event handlers

Exception Handling

Use try/catch blocks around await expressions
Avoid swallowing exceptions in async methods
Use ConfigureAwait(false) when appropriate to prevent deadlocks in library code
Propagate exceptions with Task.FromException() instead of throwing in async Task returning methods

Performance

Use Task.WhenAll() for parallel execution of multiple tasks
Use Task.WhenAny() for implementing timeouts or taking the first completed task
Avoid unnecessary async/await when simply passing through task results
Consider cancellation tokens for long-running operations

SKILL.md on GitHub