---
name: csharp-async
description: 'Get best practices for C# async programming'
---
# 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
## Common Pitfalls
- Never use `.Wait()`, `.Result`, or `.GetAwaiter().GetResult()` in async code
- Avoid mixing blocking and async code
- Don't create async void methods (except for event handlers)
- Always await Task-returning methods
## Implementation Patterns
- Implement the async command pattern for long-running operations
- Use async streams (IAsyncEnumerable<T>) for processing sequences asynchronously
- Consider the task-based asynchronous pattern (TAP) for public APIs
When reviewing my C# code, identify these issues and suggest improvements that follow these best practices.
