Browser

Browser Skill

Connects to Chrome Canary via CDP (Chrome DevTools Protocol) using an isolated bot profile.

IMPORTANT: The user's main Chrome is never touched. Canary runs in parallel with a separate profile.

When to invoke

• User says "open in browser", "browse to", "check in Chrome", "what tabs are open", etc.
• Need to read web page content
• Need to open a URL

Connection algorithm

1. Check if CDP is already running

curl -s --max-time 2 http://localhost:9222/json/version

• If response → CDP is active, go to step 3
• If no response → go to step 2

2. Launch Chrome Canary with bot profile

2a. Check if port is free

lsof -i :9222 2>/dev/null && echo "PORT_BUSY" || echo "PORT_FREE"

If port is busy — investigate what's using it.

2b. Launch Canary

Bot profile is stored in ~/.chromium-bot. It persists cookies and logins between sessions.

"/Applications/Google Chrome Canary.app/Contents/MacOS/Google Chrome Canary" \
  --remote-debugging-port=9222 \
  --user-data-dir="$HOME/.chromium-bot" \
  --no-first-run &

sleep 5

Verify connection:

curl -s --max-time 2 http://localhost:9222/json/version

If no response — wait 3 more seconds and retry.

3. List open tabs

curl -s http://localhost:9222/json/list | python3 -c "
import json, sys
tabs = json.load(sys.stdin)
pages = [t for t in tabs if t['type'] == 'page']
if not pages:
    print('No open tabs')
else:
    for i, t in enumerate(pages, 1):
        print(f\"{i}. {t['title']}\n   {t['url']}\n\")
"

4. Open a URL

curl -s -X PUT "http://localhost:9222/json/new?URL_HERE"

5. Read page content

5a. Ensure websockets is installed

python3 -c "import websockets" 2>/dev/null || pip3 install --break-system-packages websockets

5b. Read content

python3 -c "
import json, asyncio, websockets

async def get_content(ws_url):
    async with websockets.connect(ws_url) as ws:
        await ws.send(json.dumps({
            'id': 1,
            'method': 'Runtime.evaluate',
            'params': {'expression': 'document.body.innerText'}
        }))
        result = json.loads(await ws.recv())
        text = result.get('result', {}).get('result', {}).get('value', 'Could not read page')
        print(text[:15000])

import urllib.request
tabs = json.loads(urllib.request.urlopen('http://localhost:9222/json/list').read())
pages = [t for t in tabs if t['type'] == 'page']
if pages:
    asyncio.run(get_content(pages[0]['webSocketDebuggerUrl']))
else:
    print('No open tabs')
"

6. Navigate within a tab

python3 -c "
import json, asyncio, websockets

async def navigate(ws_url, url):
    async with websockets.connect(ws_url) as ws:
        await ws.send(json.dumps({
            'id': 1,
            'method': 'Page.navigate',
            'params': {'url': url}
        }))
        print(await ws.recv())

import urllib.request
tabs = json.loads(urllib.request.urlopen('http://localhost:9222/json/list').read())
pages = [t for t in tabs if t['type'] == 'page']
if pages:
    asyncio.run(navigate(pages[0]['webSocketDebuggerUrl'], 'TARGET_URL'))
"

Key details

• Browser: Chrome Canary (/Applications/Google Chrome Canary.app/)
• Bot profile: ~/.chromium-bot (isolated from main Chrome)
• CDP port: 9222
• User's main Chrome is NEVER touched — Canary runs independently
• Cookies and logins persist between sessions in the bot profile

Error handling

• If curl to port 9222 doesn't respond after launch → wait 3 more seconds and retry
• If websockets is not installed → pip3 install --break-system-packages websockets
• If Canary won't start → check pgrep -la "Chrome Canary"
• If port 9222 is occupied → lsof -i :9222 to find out by what

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: denenis-lab
• Source: denenis-lab/my-claude-skills
• License: MIT

Install and usage instructions live in the source repository linked above.