Express for Web APIs

Express is a web application framework for Node.js that provides a minimal set of tools for building HTTP servers, web applications, and APIs.

It sits on top of Node.js's HTTP capabilities and simplifies common server-side tasks such as defining routes, reading request data, sending responses, handling errors, and composing reusable middleware.

For backend developers, Express provides a lightweight foundation for turning application logic into an HTTP interface that clients can interact with.

Because Express is intentionally unopinionated, it gives developers a lot of flexibility in how they structure applications. That flexibility is useful, but it also means you need to understand the underlying HTTP concepts and make deliberate decisions about routing, validation, error handling, rate limiting, and other cross-cutting concerns.

💡 This course covers Express v4.

Learning objectives

In this course, you'll learn how to build and structure web APIs with Express.

After completing this course, you will be able to:

• Create and run an HTTP server with Express.
• Define routes for different HTTP methods and URL patterns.
• Read and process request parameters, query strings, headers, and bodies.
• Apply rate limiting to protect endpoints from excessive traffic.
• Validate incoming HTTP parameters and request bodies.
• Handle runtime errors consistently across an application.
• Serve static files through Express.
• Render dynamic responses using template engines.
• Serve API documentation from an Express application.