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An efficient server implies a lower cost of the infrastructure, 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 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. Check out the [`4.x` branch](https://github.com/fastify/fastify/tree/4.x) for `v4`. ### Table of Contents - [Quick start](#quick-start) - [Install](#install) - [Example](#example) - [Core features](#core-features) - [Benchmarks](#benchmarks) - [Documentation](#documentation) - [Ecosystem](#ecosystem) - [Support](#support) - [Team](#team) - [Hosted by](#hosted-by) - [License](#license) ### Quick start Create a folder and make it your current working directory: ```sh mkdir my-app cd my-app ``` Generate a fastify project with `npm init`: ```sh npm init fastify ``` Install dependencies: ```sh npm i ``` To start the app in dev mode: ```sh npm run dev ``` For production mode: ```sh npm start ``` Under the hood `npm init` downloads and runs [Fastify Create](https://github.com/fastify/create-fastify), which in turn uses the generate functionality of [Fastify CLI](https://github.com/fastify/fastify-cli). ### Install To install Fastify in an existing project as a dependency: ```sh npm i fastify ``` ### Example ```js // 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: ```js // 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. If you learn best by reading code, explore the official [demo](https://github.com/fastify/demo). > ## 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](https://cloud.google.com/), etc.), you may need to bind to `0.0.0.0`. Be > careful when listening on all interfaces; it comes with inherent > [security > risks](https://web.archive.org/web/20170711105010/https://snyk.io/blog/mongodb-hack-and-secure-defaults/). > See [the documentation](./docs/Reference/Server.md#listen) 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 using [JSON Schema](https://json-schema.org/) 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](https://github.com/pinojs/pino)! - **Developer friendly:** the framework is built to be very expressive and help developers 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 | These 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 * [__`Getting Started`__](./docs/Guides/Getting-Started.md) * [__`Guides`__](./docs/Guides/Index.md) * [__`Server`__](./docs/Reference/Server.md) * [__`Routes`__](./docs/Reference/Routes.md) * [__`Encapsulation`__](./docs/Reference/Encapsulation.md) * [__`Logging`__](./docs/Reference/Logging.md) * [__`Middleware`__](./docs/Reference/Middleware.md) * [__`Hooks`__](./docs/Reference/Hooks.md) * [__`Decorators`__](./docs/Reference/Decorators.md) * [__`Validation and Serialization`__](./docs/Reference/Validation-and-Serialization.md) * [__`Fluent Schema`__](./docs/Guides/Fluent-Schema.md) * [__`Lifecycle`__](./docs/Reference/Lifecycle.md) * [__`Reply`__](./docs/Reference/Reply.md) * [__`Request`__](./docs/Reference/Request.md) * [__`Errors`__](./docs/Reference/Errors.md) * [__`Content Type Parser`__](./docs/Reference/ContentTypeParser.md) * [__`Plugins`__](./docs/Reference/Plugins.md) * [__`Testing`__](./docs/Guides/Testing.md) * [__`Benchmarking`__](./docs/Guides/Benchmarking.md) * [__`How to write a good plugin`__](./docs/Guides/Write-Plugin.md) * [__`Plugins Guide`__](./docs/Guides/Plugins-Guide.md) * [__`HTTP2`__](./docs/Reference/HTTP2.md) * [__`Long Term Support`__](./docs/Reference/LTS.md) * [__`TypeScript and types support`__](./docs/Reference/TypeScript.md) * [__`Serverless`__](./docs/Guides/Serverless.md) * [__`Recommendations`__](./docs/Guides/Recommendations.md) ## Ecosystem - [Core](./docs/Guides/Ecosystem.md#core) - Core plugins maintained by the _Fastify_ [team](#team). - [Community](./docs/Guides/Ecosystem.md#community) - Community-supported plugins. - [Live Examples](https://github.com/fastify/example) - Multirepo with a broad set of real working examples. - [Discord](https://discord.gg/D3FZYPy) - Join our discord server and chat with the maintainers. ## Support Please visit [Fastify help](https://github.com/fastify/help) to view prior support issues and to ask new support questions. Version 3 of Fastify and lower are EOL and will not receive any security or bug fixes. Fastify's partner, HeroDevs, provides commercial security fixes for all unsupported versions at [https://herodevs.com/support/fastify-nes][hd-link]. Fastify's supported version matrix is available in the [Long Term Support][lts-link] documentation. ## Contributing Whether reporting bugs, discussing improvements and new ideas, or writing code, we welcome contributions from anyone and everyone. Please read the [CONTRIBUTING](./CONTRIBUTING.md) 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:** * [__Matteo Collina__](https://github.com/mcollina), , * [__Tomas Della Vedova__](https://github.com/delvedor), , * [__KaKa Ng__](https://github.com/climba03003), * [__Manuel Spigolon__](https://github.com/eomm), , * [__James Sumners__](https://github.com/jsumners), , ### Fastify Core team * [__Aras Abbasi__](https://github.com/uzlopak), * [__Harry Brundage__](https://github.com/airhorns/), , * [__Matteo Collina__](https://github.com/mcollina), , * [__Gürgün Dayıoğlu__](https://github.com/gurgunday), * [__Tomas Della Vedova__](https://github.com/delvedor), , * [__Carlos Fuentes__](https://github.com/metcoder95), , * [__Vincent Le Goff__](https://github.com/zekth) * [__Luciano Mammino__](https://github.com/lmammino), , * [__Jean Michelet__](https://github.com/jean-michelet), * [__KaKa Ng__](https://github.com/climba03003), * [__Luis Orbaiceta__](https://github.com/luisorbaiceta), , * [__Maksim Sinik__](https://github.com/fox1t), , * [__Manuel Spigolon__](https://github.com/eomm), , * [__James Sumners__](https://github.com/jsumners), , ### Fastify Plugins team * [__Harry Brundage__](https://github.com/airhorns/), , * [__Simone Busoli__](https://github.com/simoneb), , * [__Dan Castillo__](https://github.com/dancastillo), * [__Matteo Collina__](https://github.com/mcollina), , * [__Gürgün Dayıoğlu__](https://github.com/gurgunday), * [__Tomas Della Vedova__](https://github.com/delvedor), , * [__Carlos Fuentes__](https://github.com/metcoder95), , * [__Vincent Le Goff__](https://github.com/zekth) * [__Jean Michelet__](https://github.com/jean-michelet), * [__KaKa Ng__](https://github.com/climba03003), * [__Maksim Sinik__](https://github.com/fox1t), , * [__Frazer Smith__](https://github.com/Fdawgs), * [__Manuel Spigolon__](https://github.com/eomm), , ### Emeritus Contributors Great contributors to a specific area of the Fastify ecosystem will be invited to join this group by Lead Maintainers when they decide to step down from the active contributor's group. * [__Tommaso Allevi__](https://github.com/allevo), , * [__Ethan Arrowood__](https://github.com/Ethan-Arrowood/), , * [__Çağatay Çalı__](https://github.com/cagataycali), , * [__David Mark Clements__](https://github.com/davidmarkclements), , * [__dalisoft__](https://github.com/dalisoft), , * [__Dustin Deus__](https://github.com/StarpTech), , * [__Denis Fäcke__](https://github.com/SerayaEryn), , * [__Rafael Gonzaga__](https://github.com/rafaelgss), , * [__Trivikram Kamat__](https://github.com/trivikr), , * [__Ayoub El Khattabi__](https://github.com/AyoubElk), , * [__Cemre Mengu__](https://github.com/cemremengu), , * [__Salman Mitha__](https://github.com/salmanm), * [__Nathan Woltman__](https://github.com/nwoltman), , ## Hosted by [

](https://openjsf.org/projects) We are an [At-Large Project](https://github.com/openjs-foundation/cross-project-council/blob/HEAD/PROJECT_PROGRESSION.md#at-large-projects) in the [OpenJS Foundation](https://openjsf.org/). ## Sponsors Support this project by becoming a [SPONSOR](./SPONSORS.md)! Fastify has an [Open Collective](https://opencollective.com/fastify) page where we accept and manage financial contributions. ## Acknowledgments This project is kindly sponsored by: - [NearForm](https://nearform.com) - [Platformatic](https://platformatic.dev) Past Sponsors: - [LetzDoIt](https://www.letzdoitapp.com/) This list includes all companies that support one or more team members in maintaining this project. ## License Licensed under [MIT](./LICENSE). For your convenience, here is a list of all the licenses of our production dependencies: - MIT - ISC - BSD-3-Clause - BSD-2-Clause [hd-link]: https://www.herodevs.com/support/fastify-nes?utm_source=fastify&utm_medium=link&utm_campaign=github_readme [lts-link]: https://fastify.dev/docs/latest/Reference/LTS/