Chrome extension ws connect + read current tab + node js ws server

README.md

npm install ws

background.js

var ws = new WebSocket('ws://localhost:8088/post');

chrome.tabs.onUpdated.addListener((tabId, changeInfo, tab) => {
  if (changeInfo.status === "complete") {
    ws.send(tab.url);
  }
});

manifest.json

{
  "name": "Getting Started Example",
  "description": "Build an Extension!",
  "version": "1.0",
  "manifest_version": 3,
  "background": {
    "service_worker": "background.js"
  },
  "permissions": ["tabs","activeTab"]
}

server.js

const WebSocket = require('ws');
const url = require('url');

const wss = new WebSocket.Server({ port: 8088 });

wss.on('connection', function connection(ws, request) {
  const pathname = url.parse(request.url).pathname;
  var msg = '';
  if (pathname === '/post') {
    ws.on('message', function incoming(message) {
      console.log('received: %s', message);
      msg = message;
    });
  }

  if (pathname === '/get') {
    ws.on('message', function incoming(message) {
      console.log('sending : %s', message);
      ws.send(msg);
    });
  }
});