Integrate CrossWS with Deno.

To integrate CrossWS with your Deno server, you need to check for the upgrade header and then call handleUpgrade method from the adapter passing the incoming request object. The returned value is the server upgrade response.

import wsAdapter from "crossws/adapters/deno";

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

Deno.serve({ port: 3000 }, (request, info) => {
  if (request.headers.get("upgrade") === "websocket") {
    return handleUpgrade(request, info);
  return new Response(
    `<script>new WebSocket("ws://localhost:3000").addEventListener("open", (e) =>"Hello from client!"));</script>`,
    { headers: { "content-type": "text/html" } },

Adapter Hooks

  • deno:open (peer)
  • deno:message (peer, event)
  • deno:close (peer)
  • deno:error (peer, error)
See playground/deno.ts for demo and src/adapters/deno.ts for implementation.