express-js-guide

name	express.js-guide
description	Express 5+ API server guidelines for TypeScript. Apply when editing `*.ts` files with Express imports or `@types/express`. Use for route organization, error handling, authentication, testing. Keywords: Express, routes, controllers, middleware, Zod validation, JWT, error handling, CORS, Morgan.

Express.js Coding Guidelines

Requirements

• Express ≥ 5, TypeScript ≥ 5.8, Helmet/CORS/Morgan, Zod.

Essentials

• Project structure - Routes, controllers, middleware as separate modules, see reference/project-structure.md
• Input validation - Validate params/body/query with Zod at route edges, see reference/validation.md
• Error handling - Central error handler, never leak stack traces in prod, see reference/error-handling.md
• Authentication - JWT auth with role/permission middleware, see reference/authentication.md
• Response format - Consistent JSON shape and status codes, see reference/responses.md
• Testing - Unit-test controllers/middleware, integration-test routes, see reference/testing.md

Progressive disclosure

• Read reference/project-structure.md - When organizing a new Express project
• Read reference/routes.md - When defining REST endpoints or route patterns
• Read reference/controllers.md - When implementing request handlers
• Read reference/validation.md - When adding input validation to routes
• Read reference/authentication.md - When implementing JWT auth or session management
• Read reference/error-handling.md - When centralizing error responses
• Read reference/responses.md - When standardizing API response formats
• Read reference/app-setup.md - When configuring Express app initialization
• Read reference/testing.md - When writing unit or integration tests