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Module 09 — Express 5 + REST APIs

What Is Express?​

Express is a minimal, fast web framework for Node.js. It handles HTTP routing, middleware, and request/response parsing. In 2025 we use Express 5 (the major release that modernized async error handling) with TypeScript.

What You'll Build​

A fully featured REST API with:

  • Typed routes and middleware
  • Request validation
  • Structured error responses
  • JSON file persistence (before we add a real database in Module 10)

Learning Objectives​

  • Set up an Express 5 + TypeScript server
  • Define GET, POST, PUT, PATCH, DELETE routes
  • Write reusable middleware (logging, auth, validation)
  • Handle errors consistently
  • Follow REST conventions

Module Lessons​

  1. Express Setup
  2. Routing
  3. Middleware
  4. Error Handling
  5. REST Conventions

Challenge​

Build a Note Taker API:

  • GET /api/notes — return all notes
  • POST /api/notes — create a note
  • DELETE /api/notes/:id — delete a note
  • Persists to a JSON file
  • Deployed to Railway

View Challenge →