ThinkBrowse CLI

Control real browsers from Claude Code using the thinkbrowse CLI. Two modes:

• Local mode — drives your actual Chrome via the ThinkBrowse extension (free, auth cookies available)
• Cloud mode — provisions isolated Playwright browsers on Fly.io (credits, headless, stealth)

Quick Start

# Local mode — list tabs, attach, navigate, observe
thinkbrowse tabs
thinkbrowse attach <tabId>
thinkbrowse navigate "https://example.com"
thinkbrowse snapshot              # accessibility tree (best for AI)
thinkbrowse screenshot --output /tmp/page.png

# Cloud mode — create session, navigate, observe, clean up
thinkbrowse cloud start "https://example.com"
thinkbrowse snapshot
thinkbrowse screenshot --output /tmp/page.png
thinkbrowse cloud stop --all

Mode Detection

Priority: --tab flag > THINKBROWSE_TAB_ID env > working-location.json > API key (cloud).

Top 5 Patterns

1. Navigate and Observe

thinkbrowse navigate "https://example.com"
sleep 2                                    # Wait for page load + CSRF tokens
thinkbrowse snapshot                       # Read structure before interacting
thinkbrowse screenshot --output /tmp/page.png
# Then use Read tool on /tmp/page.png to view it

2. Click by Text Content (RECOMMENDED)

Direct CSS selectors often fail when elements lack unique selectors. Use evaluate:

thinkbrowse evaluate "[...document.querySelectorAll('button,a,[role=button]')].find(el=>el.textContent.trim()==='Sign In')?.click()"
sleep 1

3. Fill React Forms

# React inputs need keyboard events — use `type`, NOT `fill`
thinkbrowse click "input[type=email]"
thinkbrowse type "input[type=email]" "user@example.com"
thinkbrowse click "input[type=password]"
thinkbrowse type "input[type=password]" "password123"
thinkbrowse click "button[type=submit]"
sleep 3

4. List All Interactive Elements

thinkbrowse evaluate "[...document.querySelectorAll('button,[role=tab],[role=button]')].map(b=>({label:b.getAttribute('aria-label'),text:b.textContent.trim(),class:b.className.slice(0,50)})).filter(b=>b.text||b.label)"

5. Wait Then Act

thinkbrowse navigate "https://app.example.com"
thinkbrowse wait "button[type=submit]" --timeout 10000
thinkbrowse click "button[type=submit]"

For all 10+ patterns, see references/patterns.md.

Top 5 Anti-Patterns

1. Using text as a CSS selector

# BAD — "Timeline & Logs" is not a CSS selector
thinkbrowse click "Timeline & Logs"     # ELEMENT_NOT_FOUND

# GOOD — find by text via evaluate
thinkbrowse evaluate "[...document.querySelectorAll('button')].find(b=>b.textContent.includes('Timeline'))?.click()"

2. Using fill on React inputs

# BAD — fill uses native DOM, React won't detect the change
thinkbrowse fill "#search" "query text"

# GOOD — type uses keyboard events, triggers React onChange
thinkbrowse type "#search" "query text"

3. Screenshotting immediately after attach

# BAD — screenshot fails with "fetch failed"
thinkbrowse attach <tabId>
thinkbrowse screenshot --output /tmp/page.png   # ERROR

# GOOD — wait for connection
thinkbrowse attach <tabId>
sleep 2
thinkbrowse screenshot --output /tmp/page.png

4. Clicking a link without waiting for navigation

# BAD — extract runs before new page loads
thinkbrowse click "a[href='/next-page']"
thinkbrowse extract ".content"           # OLD page content!

# GOOD — wait for new page element
thinkbrowse click "a[href='/next-page']"
thinkbrowse wait "h1" --timeout 5000
thinkbrowse extract ".content"

5. Not cleaning up sessions

# ALWAYS release/stop when done
thinkbrowse release                # local mode
thinkbrowse cloud stop --all       # cloud mode

Output Format

All commands return JSON:

{"success": true, "command": "navigate", "durationMs": 1234, "data": {...}}
{"success": false, "error": "...", "code": "ELEMENT_NOT_FOUND", "hint": "...", "retryable": true}

Key gotchas:

• thinkbrowse url returns {"data": "https://..."} — plain string, NOT nested object
• thinkbrowse screenshot --output /tmp/x.png returns {"data": {"path": "/tmp/x.png"}} — use Read tool on that path to view it
• evaluate auto-wraps single expressions; multi-statement needs IIFE: (()=>{const x=5; return x*2})()
• evaluate does NOT await Promises — async operations return {}
• Scroll has no effect on fixed-layout pages — screenshot after to verify
• Protected iframes (Stripe, OAuth) return {"blocked": true, "handoffRequired": true} — stop automation

Timing Guidelines

Multi-Agent Coordination

Use --tab <tabId> on every command to prevent tab contention:

thinkbrowse navigate "https://site-a.com" --tab 12345
thinkbrowse navigate "https://site-b.com" --tab 67890

Or: export THINKBROWSE_TAB_ID=12345

Setup & Diagnostics

thinkbrowse doctor                        # Check bridge, extension, config
thinkbrowse config show                   # Show current config
thinkbrowse config set apiKey <key>       # Set API key for cloud mode
thinkbrowse agent-init [--name <name>]    # Set agent identity

References

• For complete command reference, see references/command-reference.md
• For all 10+ patterns and additional gotchas, see references/patterns.md
• For error codes and recovery playbooks, see references/error-recovery.md