uWebSockets.js/README.md

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<img src="https://raw.githubusercontent.com/uNetworking/uWebSockets/master/misc/logo.svg" height="180" /><br>
<i>Simple, secure</i><sup><a href="https://github.com/uNetworking/uWebSockets/tree/master/fuzzing#fuzz-testing-of-various-parsers-and-mocked-examples">[1]</a></sup><i> & standards compliant</i><sup><a href="https://unetworking.github.io/uWebSockets.js/report.pdf">[2]</a></sup><i> web server for the most demanding</i><sup><a href="https://github.com/uNetworking/uWebSockets/tree/master/benchmarks#benchmark-driven-development">[3]</a></sup><i> of applications.</i> <a href="https://github.com/uNetworking/uWebSockets/blob/master/misc/READMORE.md">Read more...</a>
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<a href="https://github.com/uNetworking/uWebSockets.js/releases"><img src="https://img.shields.io/github/v/release/uNetworking/uWebSockets.js"></a> <a href="https://lgtm.com/projects/g/uNetworking/uWebSockets.js/context:cpp"><img alt="Language grade: C/C++" src="https://img.shields.io/lgtm/grade/cpp/g/uNetworking/uWebSockets.js.svg?logo=lgtm&logoWidth=18"/></a> <img src="https://img.shields.io/badge/downloads-55%20million-pink" />

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### :bulb: Quite simple

µWebSockets.js is a C++ implementation of the WebSocket/HTTP protocols for Node.js, easy to use from JavaScript. Think of it as a **much** faster alternative to both Socket.IO and Fastify/Express.js; it comes with both router and pub/sub support. Browse the [documentation](https://unetworking.github.io/uWebSockets.js/generated/) and see the [main repo](https://github.com/uNetworking/uWebSockets). There are tons of [examples](examples) but here's the gist of it all:

```javascript
/* Non-SSL is simply App() */
require('uWebSockets.js').SSLApp({

  /* There are more SSL options, cut for brevity */
  key_file_name: 'misc/key.pem',
  cert_file_name: 'misc/cert.pem',
  
}).ws('/*', {

  /* There are many common helper features */
  idleTimeout: 30,
  maxBackpressure: 1024,
  maxPayloadLength: 512,
  compression: DEDICATED_COMPRESSOR_3KB,

  /* For brevity we skip the other events (upgrade, open, ping, pong, close) */
  message: (ws, message, isBinary) => {
    /* You can do app.publish('sensors/home/temperature', '22C') kind of pub/sub as well */
    
    /* Here we echo the message back, using compression if available */
    let ok = ws.send(message, isBinary, true);
  }
  
}).get('/*', (res, req) => {

  /* It does Http as well */
  res.writeStatus('200 OK').writeHeader('IsExample', 'Yes').end('Hello there!');
  
}).listen(9001, (listenSocket) => {

  if (listenSocket) {
    console.log('Listening to port 9001');
  }
  
});
```

### :muscle: Unfair advantage

Being written in native code directly targeting the Linux kernel makes it way faster than any JavaScript implementation.

![](misc/chart.png)

### :crossed_swords: Battle proven
We've been fully standards compliant with a perfect Autobahn|Testsuite score since 2016<sup><a href="https://unetworking.github.io/uWebSockets.js/report.pdf">[2]</a></sup>. Companies with everything to lose rely on µWebSockets on a daily basis - we power the trading APIs of [Bitfinex.com](https://bitfinex.com), handling volumes of about a billion USD every day. Other companies include [Trello](https://trello.com), where µWebSockets is serving their 50 million users with real-time board updates.

### :package: Easily installed

(Recommended) Install with `yarn add uWebSockets.js@uNetworking/uWebSockets.js#v18.12.0` or any such [release](https://github.com/uNetworking/uWebSockets.js/releases). No compiler needed.

uNetworking AB does not mutate any releases, but if you require cryptographically immutable releases you may directly refer to the commit hash instead of a named tag. Nobody is twisting anyone's arm here.

### :briefcase: Commercially supported
<a href="https://github.com/uNetworking">uNetworking AB</a> is a Swedish consulting & contracting company dealing with anything related to µWebSockets; development, support and customer success.

Don't hesitate <a href="mailto:alexhultman@gmail.com">sending a mail</a> if you're building something large, in need of advice or having other business inquiries in mind. We'll figure out what's best for both parties and make sure you're not stepping into one of the many common pitfalls.

Special thanks to BitMEX, Bitfinex, Google, Coinbase, Bitwyre and deepstreamHub for allowing the project itself to thrive on GitHub since 2016 - this project would not be possible without these beautiful companies.

<img src="https://github.com/uNetworking/uWebSockets/raw/master/misc/2018.png" />

### :family: A family
µWebSockets.js is the Node.js integration of [µWebSockets](https://github.com/uNetworking/uWebSockets); the standalone C++ project. If performance is of utter importance, you don't necessarily have to use JavaScript/Node.js but could write apps in C++ using µWebSockets directly. It works exactly the same way, and will offer unbeatable performance for those highly demanding applications. Either way - the two projects both follow the same security testing, compliance testing and receive the same bug fixes and features. They are part of the same family.

### :handshake: Permissively licensed
Intellectual property, all rights reserved.

Where such explicit notice is given, source code is licensed Apache License 2.0 which is a permissive OSI-approved license with very few limitations. Modified "forks" should be of nothing but licensed source code, and be made available under another product name. If you're uncertain about any of this, please ask before assuming.