koa-websocket

Koa v2 is now the default. For Koa v1 support install with koa-websocket@2 and see the legacy branch.

Supports ws:// and wss://

Installation

npm install koa-websocket

Usage

const Koa = require('koa'),
  route = require('koa-route'),
  websockify = require('koa-websocket');

const app = websockify(new Koa());

// Regular middleware
// Note it's app.ws.use and not app.use
app.ws.use(function(ctx, next) {
  // return `next` to pass the context (ctx) on to the next ws middleware
  return next(ctx);
});

// Using routes
app.ws.use(route.all('/test/:id', function (ctx) {
  // `ctx` is the regular koa context created from the `ws` onConnection `socket.upgradeReq` object.
  // the websocket is added to the context on `ctx.websocket`.
  ctx.websocket.send('Hello World');
  ctx.websocket.on('message', function(message) {
    // do something with the message from client
        console.log(message);
  });
}));

app.listen(3000);

Example with Let's Encrypt (the Greenlock package):

const Koa = require('koa');
const greenlock = require('greenlock-express');
const websockify = require('koa-wss');
 
const le = greenlock.create({
  // all your sweet Let's Encrypt options here
});
 
// the magic happens right here
const app = websockify(new Koa(), wsOptions, le.httpsOptions);
 
app.ws.use((ctx) => {
   // the websocket is added to the context as `ctx.websocket`.
  ctx.websocket.on('message', function(message) {
    // do something
  });
});
 
app.listen(3000);

With custom websocket options.

const Koa = require('koa'),
  route = require('koa-route'),
  websockify = require('koa-websocket');

const wsOptions = {};
const app = websockify(new Koa(), wsOptions);

app.ws.use(route.all('/', (ctx) => {
   // the websocket is added to the context as `ctx.websocket`.
  ctx.websocket.on('message', function(message) {
    // print message from the client
    console.log(message);
  });
}));

app.listen(3000);

API

websockify(KoaApp, [WebSocketOptions], [httpsOptions])

The WebSocket options object just get passed right through to the new WebSocketServer(options) call.

The optional HTTPS options object gets passed right into https.createServer(options). If the HTTPS options are passed in, koa-websocket will use the built-in Node HTTPS server to provide support for the wss:// protocol.

License

MIT