cdpproxy

cdpproxy is a websocket proxy to logs all messages on cdp connections.

Install and build

The program requires Go installed.

$ go build

Usage

You can use the proxy with an existing browser like Lightpanda.

By default cdpproxy listens websocket incoming connections on 127.0.0.1:9222. You can use the --addr option or CDP_ADDRESS env var to change the configuration.

By default cdpproxy connects to the browser on ws://127.0.0.1:9223. You can give another url by passing it as the first argument.

Usage with cdp client

You must configure your client to connect to the cdpproxy address.

Example with Puppeteer

'use scrict'

import puppeteer from 'puppeteer-core';

const browser = await puppeteer.connect({
  browserWSEndpoint: "ws://127.0.0.1:9222",
});

Example with Playwright

'use scrict'

import { chromium } from 'playwright';

const browser = await chromium.connectOverCDP({
    endpointURL: 'ws://127.0.0.1:9222',
});

Usage with Lightpanda

Start Lightpanda browser.

$ ./ligthpanda serve --port 9223

Start cdpproxy and run your cdp script to display messages.

$ ./cdpproxy
> {"method":"Browser.getVersion","id":1}
< {"id":1,"result":{"protocolVersion":"1.3","product":"Chrome/124.0.6367.29","revision":"@9e6ded5ac1ff5e38d930ae52bd9aec09bd1a68e4","userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36","jsVersion":"12.4.254.8"}}
> {"method":"Target.getBrowserContexts","id":2}
< {"id":2,"result":{"browserContextIds":[]}}

Usage with Chromium headless

Start Chromium browser.

$ chromium --headless=new --remote-debugging-port=9223

DevTools listening on ws://127.0.0.1:9223/devtools/browser/696603b7-6ac7-4f0a-99ad-cd356c7f8b7d

Start cdpproxy with the ws url and run your cdp script to display messages.

$ ./cdpproxy ws://127.0.0.1:9223/devtools/browser/696603b7-6ac7-4f0a-99ad-cd356c7f8b7d
> {"method":"Browser.getVersion","id":1}
< {"id":1,"result":{"protocolVersion":"1.3","product":"Chrome/124.0.6367.29","revision":"@9e6ded5ac1ff5e38d930ae52bd9aec09bd1a68e4","userAgent":"Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36","jsVersion":"12.4.254.8"}}
> {"method":"Target.getBrowserContexts","id":2}
< {"id":2,"result":{"browserContextIds":[]}}
> {"method":"Target.setDiscoverTargets","params":{"discover":true,"filter":[{}]},"id":3}
< {"id":3,"result":{}}