fastify

What is fastify?

Fastify is a fast and low overhead web framework for Node.js. It is highly performant and provides an extensive plugin architecture, making it suitable for building a wide range of server-side applications and services.

What are fastify's main functionalities?

Web Server

Fastify allows you to create a web server that can handle HTTP requests and send responses. The above code demonstrates setting up a simple server that responds with JSON when the root route is accessed.

const fastify = require('fastify')({ logger: true });

fastify.get('/', async (request, reply) => {
  return { hello: 'world' };
});

fastify.listen(3000, (err, address) => {
  if (err) throw err;
  fastify.log.info(`server listening on ${address}`);
});

Route Shorthand Methods

Fastify provides shorthand methods for different HTTP methods like GET, POST, etc. This makes it easy to define routes for various request types.

fastify.get('/example', (request, reply) => {
  reply.send({ message: 'This is a GET request' });
});

fastify.post('/example', (request, reply) => {
  reply.send({ message: 'This is a POST request' });
});

Schema Validation

Fastify supports schema validation for request payloads, query strings, and parameters using JSON Schema. This ensures that the data received is in the expected format.

const schema = {
  body: {
    type: 'object',
    required: ['name'],
    properties: {
      name: { type: 'string' },
      age: { type: 'number' }
    }
  }
};

fastify.post('/user', { schema }, (request, reply) => {
  // Handle request knowing that the body has been validated against the schema
});

Plugins

Fastify has a powerful plugin system that allows you to extend its core functionality. Plugins can add new features, routes, services, and decorators to the Fastify instance.

const myPlugin = async (fastify, options) => {
  fastify.decorate('utility', () => {
    return 'something useful';
  });
};

fastify.register(myPlugin);

// Now you can use fastify.utility() in your application

Lifecycle Hooks

Fastify provides lifecycle hooks that can be used to execute code at various stages of the request/response cycle, such as onRequest, preHandler, onResponse, etc.

fastify.addHook('onRequest', (request, reply, done) => {
  // Perform some operations before the request handler is executed
  done();
});

Other packages similar to fastify

express

Express is one of the most popular web frameworks for Node.js. It is known for its simplicity and minimalism. Compared to Fastify, Express has a larger ecosystem and community but may not be as performant due to its less optimized architecture.

koa

Koa is a web framework designed by the creators of Express, aiming to be a smaller, more expressive, and more robust foundation for web applications and APIs. Koa uses async functions to eliminate callbacks and improve error handling. It is less opinionated than Fastify and has a smaller footprint.

hapi

Hapi is a rich framework for building applications and services, known for its powerful plugin system. It is designed to be more configurable and to provide a richer set of features out of the box compared to Fastify, which can make it heavier and potentially slower.

restify

Restify is a Node.js web service framework optimized for building semantically correct RESTful web services ready for production use at scale. Restify is similar to Fastify in terms of performance but is more focused on API creation than being a general-purpose web framework.

README

An efficient server implies a lower cost of the infrastructure, a better responsiveness under load and happy users. How can you efficiently handle the resources of your server, knowing that you are serving the highest number of requests as possible, without sacrificing security validations and handy development?

Enter Fastify. Fastify is a web framework highly focused on speed and low overhead. It is inspired from Hapi and Express and as far as we know, it is one of the fastest web frameworks in town. Use Fastify can increase your throughput up to 100%.

Install

npm i fastify --save

Example

// Require the framework and instantiate it
const fastify = require('fastify')()

// Declare a route
fastify.get('/', function (request, reply) {
  reply.send({ hello: 'world' })
})

// Run the server!
fastify.listen(3000, function (err) {
  if (err) throw err
  console.log(`server listening on ${fastify.server.address().port}`)
})

Do you want to know more? Head to the Getting Started.

Core features

• 100% asynchronous: all the core is implemented with asynchronous code, in this way not even a millisecond is wasted.
• Highly performant: as far as we know, Fastify is one of the fastest web frameworks in town, depending on the code complexity we can serve up to 20000 request per second.
• Extendible: Fastify is fully extensible via its hooks, plugins and decorators.
• Schema based: even if it is not mandatory we recommend to use JSON Schema to validate your routes and serialize your outputs, internally Fastify compiles the schema in an highly performant function.
• Logging: logs are extremely important but are costly; we chose the best logger to almost remove this cost, Pino!
• Developer friendly: the framework is built to be very expressive and help the developer in his daily use, without sacrificing performance and security.

Benchmarks

Machine: Intel Xeon E5-2686 v4 @ 2.30GHz (4 cores, 8 threads), 16GiB RAM (Amazon EC2 m4.xlarge)

Method:: autocannon -c 100 -d 5 -p 10 localhost:3000 * 2, taking the second average

Framework	Version	Router?	Requests/sec
hapi	16.5.2	✓	4,226
Restify	5.2.0	✓	16,395
Express	4.15.4	✓	18,740
Koa (koa-router)	2.3.0 (koa-router@7.2.1)	✓	21,361
take-five	1.3.4	✓	25,838
Koa	2.3.0	✗	26,228
Fastify	0.27.0	✓	29,340
-
http.Server	8.4.0	✗	37,846

Benchmarks taken using https://github.com/fastify/benchmarks.

Documentation

• Getting Started
• Server Methods
• Routes
• Logging
• Middlewares
• Hooks
• Decorators
• Validation and Serialize
• Lifecycle
• Reply
• Request
• Content Type Parser
• Plugins
• Testing
• Plugins Guide

Ecosystem

• fastify-accepts to have accepts in your request object.
• fastify-accepts-serializer to serialize to output according to Accept header
• fastify-apollo Run an Apollo Server with Fastify.
• fastify-auth Run multiple auth functions in Fastify
• fastify-bearer-auth Bearer auth plugin for Fastify
• fastify-cookie Parse and set cookie headers
• fastify-env Load and check configuration
• fastify-formbody Plugin to parse x-www-form-urlencoded bodies
• fastify-helmet Important security headers for Fastify
• fastify-jwt JWT utils for Fastify, internally uses jsonwebtoken
• fastify-leveldb Plugin to share a common LevelDB connection across Fastify.
• fastify-mongodb Fastify MongoDB connection plugin, with this you can share the same MongoDb connection pool in every part of your server.
• fastify-multipart Multipart support for Fastify
• fastify-pigeon Bankai assets compiler for Fastify
• fastify-react React server side rendering support for Fastify with Next
• fastify-redis Fastify Redis connection plugin, with this you can share the same Redis connection in every part of your server.
• fastify-sse to provide Server-Sent Events with reply.sse( … ) to Fastify
• fastify-swagger Swagger documentation generator for Fastify
• fastify-websocket WebSocket support for Fastify. Built upon websocket-stream
• point-of-view Templates rendering (ejs, pug, handlebars, marko) plugin support for Fastify.
• fastify-orientdb Fastify OrientDB connection plugin, with this you can share the orientdb connection in every part of your server.
• More coming soon

Team

Matteo Collina

https://github.com/mcollina

https://www.npmjs.com/~matteo.collina

https://twitter.com/matteocollina

Tomas Della Vedova

https://github.com/delvedor

https://www.npmjs.com/~delvedor

https://twitter.com/delvedor

Acknowledgements

This project is kindly sponsored by:

• nearForm
• LetzDoIt

License

Licensed under MIT.