What are Action Filters in ASP.NET Web API?
Updated Apr 28, 2026
Short answer
Action filters allow executing logic before and after controller actions.
Deep explanation
Action filters are part of the request pipeline and are used for cross-cutting concerns like logging, validation, and performance tracking. They execute before and/or after an action method.
Real-world example
Logging request details for debugging and monitoring.
Common mistakes
- Putting business logic inside filters.
Follow-up questions
- What is filter pipeline?
- Why filters?