csharp-async Skill (awesome-copilot) for Claude: What It Does and How to Install It

Makes Claude review C# code against async programming best practices and suggest fixes.

Installs: 11K; on skills.sh
Stars: 40.7K; on GitHub
Updated: Oct 2026; last repo commit

This is a checklist for Claude with six groups of rules: naming, return types, exception handling, performance, common pitfalls and implementation patterns. Examples are the Async suffix, Task<T> over async void, Task.WhenAll() for parallel work and never blocking with .Wait() or .Result.

It ends by asking Claude to identify these issues in your C# code and suggest improvements that follow them. It bundles no scripts and names no tools or keys. It needs C# code of your own to review.

Good for

C# developers reviewing async and await code
Teams chasing deadlocks and blocking calls in async paths
Library authors deciding on ConfigureAwait and ValueTask

Install csharp-async

Claude Code

Copy this prompt.

Install the csharp-async skill in Claude Code. Run this command:

npx skills add https://github.com/github/awesome-copilot --skill csharp-async

Then check that it loaded and tell me how to use it.

2
Paste it into Claude Code. It shows the change and asks before running it.

Requires Node.js.

From its listing on skills.sh. Source.

What's in the skill

When it loads

Get best practices for C# async programming

Sections in SKILL.md

Naming Conventions
Return Types
Exception Handling
Performance
Common Pitfalls
Implementation Patterns

Key facts

Author: github (awesome-copilot repo owner)
License: MIT
Installs on skills.sh: 10,970 (Nov 2, 2026)
GitHub stars: 40,666 for the whole github/awesome-copilot repo (Nov 2, 2026)
Last repo commit: Oct 30, 2026
What it includes: 1 file: SKILL.md. The folder has no other files
Needs: C# code to review. SKILL.md names no tools or keys

What it includes

Use the Async suffix and match the synchronous name
For example GetDataAsync() for GetData().
Try: “Review this service class for async mistakes.”
Read · Naming conventions
Task<T>, Task, ValueTask<T> and avoiding async void
Use ValueTask<T> for high-performance cases. Allow async void only for event handlers.
Read · Return types
try/catch around awaits, no swallowed exceptions
Use ConfigureAwait(false) where appropriate in library code, and Task.FromException() instead of throwing in Task-returning methods.
Read · Exception handling
Task.WhenAll, Task.WhenAny and cancellation tokens
Avoid unnecessary async and await when passing a task through.
Read · Performance
No .Wait(), .Result or GetAwaiter().GetResult()
Do not mix blocking and async code, and always await Task-returning methods.
Read · Common pitfalls
Async command pattern, IAsyncEnumerable<T>, TAP
Use async streams for sequences and the task-based asynchronous pattern for public APIs.
Read · Implementation patterns

From the official docs

Questions

What does the csharp-async skill do?

It gives Claude a checklist of C# async best practices. Claude uses it to find problems in your code, such as blocking calls or async void, and suggest improvements.

Which C# versions does it cover?

SKILL.md names no version. It mentions Task, ValueTask, ConfigureAwait and IAsyncEnumerable, so tell Claude your target framework.

Does it change my code?

SKILL.md asks Claude to identify issues and suggest improvements. Any edits come from what you ask Claude to do next.

Does it need any tools or keys?

SKILL.md names none and the folder bundles only SKILL.md.

Is there a plugin that includes it?

Yes, for GitHub Copilot CLI. The awesome-copilot marketplace lists a plugin named csharp-dotnet-development, and its plugin.json lists csharp-async with 8 other skills (9 in total) and 1 agent. Its README gives copilot plugin install csharp-dotnet-development@awesome-copilot. That is a Copilot CLI command, not a Claude Code one.

Is it safe?

It bundles no scripts and defines no commands to run. Any code changes come from Claude editing your files when you ask, so review the diff. The awesome-copilot README says its customizations come from third-party developers and asks you to inspect them before installing.

Information

updated Nov 2, 2026

Repository: github/awesome-copilot
Folder: skills/csharp-async

github/awesome-copilot skills.sh

Sources

Docs, issue trackers and discussions this page is built from.

Show all 4

csharp-async SKILL.md · github.com
awesome-copilot README · github.com
csharp-dotnet-development plugin.json · github.com
csharp-dotnet-development plugin README · github.com