Fastify

Fastify is a web framework for Node.js that focuses on low overhead, developer experience and a plugin system. It is built for servers that need to handle many requests while keeping validation and error handling in place.

You define routes with JSON Schema, and Fastify uses those schemas to validate incoming data and speed up response serialisation. Plugins, hooks and decorators let you split an app into isolated parts. Logging uses Pino, a fast logger, so logs add little cost to each request.

• JSON Schema validation for routes
• Fast response serialisation from schemas
• Plugins, hooks and decorators for structure
• TypeScript type declarations included

Node.js backend teams and API developers who want a framework that is quick to run and clear to read. It is a good fit for services where request validation and typed handlers matter as much as raw speed.

Fastify is open source under the MIT licence and free to use. Its plugin encapsulation means that a plugin's decorators stay within its own scope unless you share them, which takes some learning. The docs show how to pair it with TypeBox for type-safe schemas.