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fastify

Fast and low overhead web framework, for Node.js

5.1.0
latest
Source
npm

Version published: last month

Weekly downloads: 2.1M; decreased by-11.33%

Maintainers: 4

Weekly downloads

Created: 8 years ago

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

Open Collective backers and sponsors

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 v5 release, which is not released/LTS yet. Check out the 4.x branch for v4.

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

// Require the framework and instantiate it

// ESM
import Fastify from 'fastify'

const fastify = Fastify({
  logger: true
})
// CommonJs
const fastify = require('fastify')({
  logger: true
})

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

// Run the server!
fastify.listen({ port: 3000 }, (err, address) => {
  if (err) throw err
  // Server is now listening on ${address}
})

with async-await:

// ESM
import Fastify from 'fastify'

const fastify = Fastify({
  logger: true
})
// CommonJs
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
  // Server is now listening on ${address}
})

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

Fastify Plugins team

Great Contributors

Great contributors on a specific area in the Fastify ecosystem will be invited to join this group by Lead Maintainers.

Past Collaborators

Hosted by

We are a At-Large Project in the OpenJS Foundation.

Acknowledgements

This project is kindly sponsored by:

Past Sponsors:

LetzDoIt

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

Keywords

FAQs

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Package last updated on 31 Oct 2024

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Install

fastify

What is fastify?

What are fastify's main functionalities?

Other packages similar to fastify

Table of Contents

Quick start

Install

Example

Note

Core features

Benchmarks

Documentation

Ecosystem

Support

Contributing

Team

Fastify Core team

Fastify Plugins team

Great Contributors

Hosted by

Sponsors

Acknowledgements

License

Keywords

Related posts

fastify

What is fastify?

What are fastify's main functionalities?

Other packages similar to fastify

express

koa

hapi

restify

Table of Contents

Quick start

Install

Example

Note

Core features

Benchmarks

Documentation

Ecosystem

Support

Contributing

Team

Fastify Core team

Fastify Plugins team

Great Contributors

Hosted by

Sponsors

Acknowledgements

License

Keywords

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