autoreg-skills-max/skills/th-autoreg/references/chrome-cdp-launch.md

Chrome CDP Launch Procedure

Chrome 151+ Breaking Change

Chrome 151+ requires --remote-allow-origins=* for WebSocket connections to CDP. Without it: Handshake status 403 Forbidden - Rejected an incoming WebSocket connection.

Full Launch Command (Windows)

# Kill existing Chrome instances
taskkill /F /IM chrome.exe 2>/dev/null

# Launch with CDP enabled
"C:\Program Files\Google\Chrome\Application\chrome.exe" \
  --remote-debugging-port=9222 \
  --remote-allow-origins=* \
  --user-data-dir=%USERPROFILE%/.chrome-cdp-profile \
  --no-first-run \
  --no-default-browser-check

Verify CDP is alive

curl -s http://127.0.0.1:9222/json/version
# Expected: {"Browser": "Chrome/151.0.7922.109", ...}

Python: kill + launch

import subprocess, time, os

subprocess.run(['taskkill', '/F', '/IM', 'chrome.exe'], capture_output=True)
time.sleep(2)

user_data = os.path.expanduser("~/.chrome-cdp-profile")
os.makedirs(user_data, exist_ok=True)

subprocess.Popen([
    r"C:\Program Files\Google\Chrome\Application\chrome.exe",
    f'--user-data-dir={user_data}',
    '--remote-debugging-port=9222',
    '--remote-allow-origins=*',
    '--no-first-run',
    '--no-default-browser-check',
], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)

Python: health check

import urllib.request, json

try:
    resp = urllib.request.urlopen("http://127.0.0.1:9222/json/version", timeout=3)
    data = json.loads(resp.read())
    print(f"CDP OK: {data.get('Browser', 'unknown')}")
except Exception as e:
    print(f"CDP DEAD: {e}")

Common Errors

Error	Cause	Fix
403 Forbidden on WebSocket	Chrome 151+ without --remote-allow-origins	Add --remote-allow-origins=*
Connection refused on :9222	Chrome not launched with --remote-debugging-port	Kill all Chrome, relaunch with flag
user-data-dir is already in use	Another Chrome instance using same profile	Use unique --user-data-dir path
taskkill not finding Chrome	Chrome running as background process	Check with tasklist /FI "IMAGENAME eq chrome.exe"