express

Express Skill

Fast, unopinionated, minimalist web framework for Node.js.

Ecosystem Graph

graph LR
  express["Express"]
  express -- "alternative to" --> fastapi
  express -- "alternative to" --> hono
  express -- "alternative to" --> nestjs
  express -- "works well with" --> redis

Quick Start

Express is the most mature Node.js HTTP framework. It utilizes a simple middleware chain architecture.

npm install express cors

Production Patterns

Controller Pattern

Do not write massive anonymous functions inside your app.get() routes. Extract business logic into dedicated controller files (e.g., user.controller.js) and pass them to the Express router.

Architecture & Scaling

Middleware Chains

Express executes middleware sequentially. Always ensure your JSON body parser (express.json()) is registered before the routes that need to read req.body. Ensure you call next() to pass control.

Error Recovery

Express 4 does not automatically catch asynchronous errors. You must wrap your async route handlers in a try/catch block and pass the error to next(err). (Note: Express 5 changes this behavior). Always register a global error handler at the very bottom of your middleware chain.

Security Notes

Install and configure helmet to automatically set secure HTTP headers. Rate limit endpoints using express-rate-limit backed by Redis to prevent brute-force attacks.

Relationships

Alternatives: fastapi, hono, nestjs

Works Well With: redis

References

• Express Docs

Why use this skill

Use this when your agent works with express — structured patterns beat pasted docs and prevent common hallucinations.

AI pitfalls

• Using outdated SDK or API versions from training data
• Inventing environment variable names
• Omitting error handling and retry logic

Production checklist

• Secrets in environment variables, not source code
• Error handling and logging in place
• Rate limits and timeouts configured