What is the Chain of Responsibility Pattern?

Updated Apr 28, 2026

Short answer

A behavioral pattern that lets you pass requests along a chain of handlers.

Deep explanation

Upon receiving a request, each handler decides either to process the request or to pass it to the next handler in the chain. It decouples the sender of a request from its receiver.

Real-world example

Middleware in web frameworks (like Express.js or ASP.NET). A request passes through logging, authentication, and validation middlewares.

Common mistakes

  • Building a chain where a request can fall off the end unhandled without any fallback or error mechanism.

Follow-up questions

  • Does every handler process the request?

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