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.
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 providing the best
developer experience with the least overhead and a powerful plugin architecture.
It is inspired by Hapi and Express and as far as we know, it is one of the
fastest web frameworks in town.
The main
branch refers to the Fastify v4
release. Check out the
v3.x
branch for v3
.
Table of Contents
Quick start
Create a folder and make it your current working directory:
mkdir my-app
cd my-app
Generate a fastify project with npm init
:
npm init fastify
Install dependencies:
npm i
To start the app in dev mode:
npm run dev
For production mode:
npm start
Under the hood npm init
downloads and runs Fastify
Create, which in turn uses the
generate functionality of Fastify CLI.
Install
To install Fastify in an existing project as a dependency:
Install with npm:
npm i fastify
Install with yarn:
yarn add fastify
Example
import Fastify from 'fastify'
const fastify = Fastify({
logger: true
})
const fastify = require('fastify')({
logger: true
})
fastify.get('/', (request, reply) => {
reply.send({ hello: 'world' })
})
fastify.listen({ port: 3000 }, (err, address) => {
if (err) throw err
})
with async-await:
import Fastify from 'fastify'
const fastify = Fastify({
logger: true
})
const fastify = require('fastify')({
logger: true
})
fastify.get('/', async (request, reply) => {
reply.type('application/json').code(200)
return { hello: 'world' }
})
fastify.listen({ port: 3000 }, (err, address) => {
if (err) throw err
})
Do you want to know more? Head to the Getting Started
.
Note
.listen
binds to the local host, localhost
, interface by default
(127.0.0.1
or ::1
, depending on the operating system configuration). If
you are running Fastify in a container (Docker,
GCP, etc.), you may need to bind to 0.0.0.0
. Be
careful when deciding to listen on all interfaces; it comes with inherent
security
risks.
See the documentation for more
information.
Core features
- 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 76+
thousand requests per second.
- Extensible: 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 a 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 their daily use, without sacrificing performance and
security.
Benchmarks
Machine: EX41S-SSD, Intel Core i7, 4Ghz, 64GB RAM, 4C/8T, SSD.
Method:: autocannon -c 100 -d 40 -p 10 localhost:3000
* 2, taking the
second average
Framework | Version | Router? | Requests/sec |
---|
Express | 4.17.3 | ✓ | 14,200 |
hapi | 20.2.1 | ✓ | 42,284 |
Restify | 8.6.1 | ✓ | 50,363 |
Koa | 2.13.0 | ✗ | 54,272 |
Fastify | 4.0.0 | ✓ | 77,193 |
- | | | |
http.Server | 16.14.2 | ✗ | 74,513 |
Benchmarks taken using https://github.com/fastify/benchmarks. This is a
synthetic, "hello world" benchmark that aims to evaluate the framework overhead.
The overhead that each framework has on your application depends on your
application, you should always benchmark if performance matters to you.
Documentation
中文文档地址
Ecosystem
- Core - Core plugins maintained by the
Fastify team.
- Community - Community supported
plugins.
- Live Examples - Multirepo with a broad
set of real working examples.
- Discord - Join our discord server and chat with
the maintainers.
Support
Please visit Fastify help to view prior
support issues and to ask new support questions.
Contributing
Whether reporting bugs, discussing improvements and new ideas or writing code,
we welcome contributions from anyone and everyone. Please read the CONTRIBUTING
guidelines before submitting pull requests.
Team
Fastify is the result of the work of a great community. Team members are
listed in alphabetical order.
Lead Maintainers:
Fastify Core team
- Tommaso Allevi,
https://twitter.com/allevitommaso, https://www.npmjs.com/~allevo
- Harry Brundage,
https://twitter.com/harrybrundage, https://www.npmjs.com/~airhorns
- David Mark Clements,
https://twitter.com/davidmarkclem,
https://www.npmjs.com/~davidmarkclements
- Matteo Collina,
https://twitter.com/matteocollina, https://www.npmjs.com/~matteo.collina
- Tomas Della Vedova,
https://twitter.com/delvedor, https://www.npmjs.com/~delvedor
- Dustin Deus,
https://twitter.com/dustindeus, https://www.npmjs.com/~starptech
- Ayoub El Khattabi,
https://twitter.com/ayoubelkh, https://www.npmjs.com/~ayoubelk
- Denis Fäcke,
https://twitter.com/serayaeryn, https://www.npmjs.com/~serayaeryn
- Carlos Fuentes,
https://twitter.com/metcoder95, https://www.npmjs.com/~metcoder95
- Rafael Gonzaga,
https://twitter.com/_rafaelgss, https://www.npmjs.com/~rafaelgss
- Vincent Le Goff
- Luciano Mammino,
https://twitter.com/loige, https://www.npmjs.com/~lmammino
- Luis Orbaiceta,
https://twitter.com/luisorbai, https://www.npmjs.com/~luisorbaiceta
- Maksim Sinik,
https://twitter.com/maksimsinik, https://www.npmjs.com/~fox1t
- Manuel Spigolon,
https://twitter.com/manueomm, https://www.npmjs.com/~eomm
- James Sumners,
https://twitter.com/jsumners79, https://www.npmjs.com/~jsumners
- Aras Abbasi,
https://www.npmjs.com/~uzlopak
- Gürgün Dayıoğlu,
https://www.npmjs.com/~gurgunday
Fastify Plugins team
- Matteo Collina,
https://twitter.com/matteocollina, https://www.npmjs.com/~matteo.collina
- Harry Brundage,
https://twitter.com/harrybrundage, https://www.npmjs.com/~airhorns
- Tomas Della Vedova,
https://twitter.com/delvedor, https://www.npmjs.com/~delvedor
- Ayoub El Khattabi,
https://twitter.com/ayoubelkh, https://www.npmjs.com/~ayoubelk
- Carlos Fuentes,
https://twitter.com/metcoder95, https://www.npmjs.com/~metcoder95
- Vincent Le Goff
- Salman Mitha,
https://www.npmjs.com/~salmanm
- Maksim Sinik,
https://twitter.com/maksimsinik, https://www.npmjs.com/~fox1t
- Frazer Smith, https://www.npmjs.com/~fdawgs
- Manuel Spigolon,
https://twitter.com/manueomm, https://www.npmjs.com/~eomm
- Simone Busoli,
https://twitter.com/simonebu, https://www.npmjs.com/~simoneb
- Gürgün Dayıoğlu,
https://www.npmjs.com/~gurgunday
Great Contributors
Great contributors on a specific area in the Fastify ecosystem will be invited
to join this group by Lead Maintainers.
Past Collaborators
- Çağatay Çalı,
https://twitter.com/cagataycali, https://www.npmjs.com/~cagataycali
- Trivikram Kamat,
https://twitter.com/trivikram, https://www.npmjs.com/~trivikr
- Cemre Mengu,
https://twitter.com/cemremengu, https://www.npmjs.com/~cemremengu
- Nathan Woltman,
https://twitter.com/NathanWoltman, https://www.npmjs.com/~nwoltman
- Ethan Arrowood,
https://twitter.com/arrowoodtech, https://www.npmjs.com/~ethan_arrowood
Hosted by
We are a At-Large
Project
in the OpenJS Foundation.
Support this project by becoming a SPONSOR!
Fastify has an Open Collective
page where we accept and manage financial contributions.
Acknowledgements
This project is kindly sponsored by:
Past Sponsors:
This list includes all companies that support one or more of the team members
in the maintenance of this project.
License
Licensed under MIT.
For your convenience, here is a list of all the licenses of our production
dependencies:
- MIT
- ISC
- BSD-3-Clause
- BSD-2-Clause