Integrate CrossWS with Node.js using ws or uWebSockets.js

To integrate CrossWS with your Node.js HTTP server, you need to connect the upgrade event to the handleUpgrade method returned from the adapter. CrossWS uses a prebundled version of ws.

import { createServer } from "node:http";
import wsAdapter from "crossws/adapters/node";

const server = createServer((req, res) => {
    `<script>new WebSocket("ws://localhost:3000").addEventListener('open', (e) =>"Hello from client!"));</script>`,

const { handleUpgrade } = wsAdapter({ message: console.log });
server.on("upgrade", handleUpgrade);

Adapter Hooks

  • node:open (peer)
  • node:message (peer, data, isBinary)
  • node:close (peer, code, reason)
  • node:error (peer, error)
  • node:ping (peer)
  • node:pong (peer)
  • node:unexpected-response (peer, req, res)
  • node:upgrade (peer, req)
See playground/node.ts for demo and src/adapters/node.ts for implementation.


Integrate CrossWS with Node.js using uWebSockets.js.

Instead of using ws you can use uWebSockets.js for Node.js servers.

import { App } from "uWebSockets.js";
import wsAdapter from "crossws/adapters/uws";

const { websocket } = wsAdapter({
  hooks: {
    message: console.log,

const server = App().ws("/*", websocket);

server.get("/*", (res, req) => {
  res.writeStatus("200 OK").writeHeader("Content-Type", "text/html");
    `<script>new WebSocket("ws://localhost:3000").addEventListener('open', (e) =>"Hello from client!"));</script>`,

server.listen(3001, () => {
  console.log("Listening to port 3001");

Adapter Hooks

  • uws:open (ws)
  • uws:message (ws, message, isBinary)
  • uws:close (ws, code, message)
  • uws:ping (ws, message)
  • uws:pong (ws, message)
  • uws:drain (ws)
  • uws:upgrade (res, req, context)
  • uws:subscription (ws, topic, newCount, oldCount)
See playground/node-uws.ts for demo and src/adapters/node-uws.ts for implementation.