Express Middleware Patterns

A guide to building robust Express.js APIs with well-structured middleware patterns for authentication, validation, and error handling.

Usage

Ask about Express middleware patterns, error handling, authentication, or API architecture.

Examples

• "Create an error handling middleware with proper status codes"
• "How do I chain authentication and authorization middleware?"
• "Build a request validation middleware with Zod"

Guidelines

• Always call next() or send a response in middleware
• Put error handling middleware last with four parameters
• Use middleware factories for configurable behavior
• Keep middleware focused on a single responsibility
• Order middleware from general to specific