browser
Debug-first browser automation with always-on visibility. USE WHEN browser, screenshot, navigate, web testing, verify UI, VERIFY phase, debug web page. Session auto-starts, captures console/network by default.
When & Why to Use This Skill
This Claude skill provides a debug-first browser automation environment designed for high visibility and seamless web interaction. It streamlines the process of navigating web pages, capturing screenshots, and verifying UI components while automatically monitoring console logs and network requests. By prioritizing diagnostic data by default, it enables developers to identify frontend errors and failed API calls instantly, making it an essential tool for web testing, automated workflows, and real-time troubleshooting.
Use Cases
- Frontend Debugging: Automatically capture console errors, warnings, and failed network requests (4xx/5xx) to diagnose issues without manual inspection.
- UI Verification & QA: Use the 'VERIFY' phase to ensure web changes are correctly rendered and functional by analyzing screenshots and page diagnostics.
- Automated Web Workflows: Execute complex user interactions such as clicking elements, filling forms, and running custom JavaScript to automate repetitive online tasks.
- Performance & Network Monitoring: Track network statistics, request timings, and payload sizes to optimize page load speeds and verify API integrations.
- Headless Browser Testing: Run automated tests in a headless environment with the ability to quickly open the session in a GUI browser for manual review when needed.
| name | Browser |
|---|---|
| description | Debug-first browser automation with always-on visibility. Console logs, network requests, and errors captured by default. USE WHEN browser, screenshot, debug web, verify UI, troubleshoot frontend. |
| version | 2.0.0 |
Customization
Before executing, check for user customizations at:
~/.claude/skills/CORE/USER/SKILLCUSTOMIZATIONS/Browser/
If this directory exists, load and apply any PREFERENCES.md, configurations, or resources found there. These override default behavior. If the directory does not exist, proceed with skill defaults.
Browser v2.0.0 - Debug-First Browser Automation
Debugging visibility by DEFAULT. Console logs, network requests, and errors are always captured. No opt-in required.
Philosophy
Debugging shouldn't be opt-in. Like good logging frameworks - you don't turn on logging when you have a problem, you have it enabled from the start so the data exists when problems occur.
Headless by default. All automation runs in headless mode. When the user says "show me" or wants to see what the assistant is seeing, open the URL in their preferred browser from ~/.claude/skills/CORE/USER/TECHSTACKPREFERENCES.md:
# Open URL in user's preferred browser
open -a "$BROWSER" "<url>" # BROWSER from tech stack prefs
v2.0.0 Changes:
- Session auto-starts on first use (no explicit
session start) - Console and network capture always enabled
- Diagnostic output included by default
- 30-minute idle timeout (auto-cleanup)
- New primary command:
Browse.ts <url>for full diagnostics
Quick Start
# Navigate with full diagnostics (PRIMARY COMMAND)
bun run ~/.claude/skills/Browser/Tools/Browse.ts https://example.com
# Output:
# 📸 Screenshot: /tmp/browse-1704614400.png
# 🔴 Console Errors (2): ...
# 🌐 Failed Requests (1): ...
# 📊 Network: 34 requests | 1.2MB | avg 120ms
# ✅ Page: "Example" loaded successfully
Session auto-starts. No setup needed.
Commands
Primary - Navigate with Diagnostics
bun run Browse.ts <url>
Navigates to URL, takes screenshot, and reports:
- Console errors and warnings
- Failed network requests (4xx, 5xx)
- Network statistics
- Page load status
Query Commands
bun run Browse.ts errors # Console errors only
bun run Browse.ts warnings # Console warnings only
bun run Browse.ts console # All console output
bun run Browse.ts network # All network activity
bun run Browse.ts failed # Failed requests only (4xx, 5xx)
Interaction Commands
bun run Browse.ts click <selector> # Click element
bun run Browse.ts fill <selector> <value> # Fill input
bun run Browse.ts type <selector> <text> # Type with delay
bun run Browse.ts screenshot [path] # Take screenshot
bun run Browse.ts navigate <url> # Navigate without report
bun run Browse.ts eval "<javascript>" # Execute JavaScript
bun run Browse.ts open <url> # Open in user's preferred browser (from tech stack prefs)
Management Commands
bun run Browse.ts status # Session info
bun run Browse.ts restart # Fresh session (clears logs)
bun run Browse.ts stop # Stop session (rarely needed)
Debugging Workflow
Scenario: "Why isn't the user list loading?"
# Step 1: Load the page
$ bun run Browse.ts https://myapp.com/users
📸 Screenshot: /tmp/browse-xxx.png
🔴 Console Errors (1):
• TypeError: Cannot read property 'map' of undefined
🌐 Failed Requests (1):
• GET /api/users → 500 Internal Server Error
📊 Network: 23 requests | 847KB | avg 89ms
⚠️ Page: "Users" loaded with issues
Immediately know:
- API returning 500
- Frontend JS crashing because no data
- Specific error location
Step 2: Dig deeper
# Full console output
$ bun run Browse.ts console
# All network activity
$ bun run Browse.ts network
# Just the failures
$ bun run Browse.ts failed
Architecture
Auto-Start Session
First command auto-starts a persistent browser session:
Any command → ensureSession() → Session running?
├─ Yes → Execute command
└─ No → Start session → Execute command
No explicit session start needed.
Always-On Event Capture
From the moment the browser launches:
- Console logs - All
console.log,console.error, etc. - Network requests - Every request with headers, timing, size
- Network responses - Status codes, response times, sizes
- Page errors - Uncaught exceptions, promise rejections
Idle Timeout
Session auto-closes after 30 minutes of inactivity:
- No zombie processes
- No manual cleanup needed
- Restarts automatically on next command
Comparison to v1.x
| Aspect | v1.x | v2.0.0 |
|---|---|---|
| Session management | Manual session start/stop |
Automatic |
| Console capture | Only in session mode | Always |
| Network capture | Only in session mode | Always |
| Error visibility | Must query explicitly | Default in output |
| Idle cleanup | Manual stop | Auto 30-min timeout |
| Primary command | screenshot <url> |
<url> (full diagnostic) |
API Reference
CLI Tool
Location: ~/.claude/skills/Browser/Tools/Browse.ts
| Command | Description |
|---|---|
<url> |
Navigate with full diagnostics |
errors |
Show console errors |
warnings |
Show console warnings |
console |
Show all console output |
network |
Show network activity |
failed |
Show failed requests |
screenshot [path] |
Take screenshot |
navigate <url> |
Navigate without report |
click <selector> |
Click element |
fill <sel> <val> |
Fill input |
type <sel> <text> |
Type with delay |
eval "<js>" |
Execute JavaScript |
open <url> |
Open in user's preferred browser (tech stack prefs) |
status |
Session info |
restart |
Fresh session |
stop |
Stop session |
Server Endpoints
Location: ~/.claude/skills/Browser/Tools/BrowserSession.ts
| Endpoint | Method | Description |
|---|---|---|
/diagnostics |
GET | Full diagnostic summary |
/console |
GET | Console logs |
/network |
GET | Network logs |
/health |
GET | Health check |
/session |
GET | Session info |
/navigate |
POST | Navigate (clears logs) |
/click |
POST | Click element |
/fill |
POST | Fill input |
/screenshot |
POST | Take screenshot |
/evaluate |
POST | Run JavaScript |
/stop |
POST | Stop server |
TypeScript API
For complex automation, use the TypeScript API directly:
import { PlaywrightBrowser } from '~/.claude/skills/Browser/index.ts'
const browser = new PlaywrightBrowser()
await browser.launch({ headless: true })
await browser.navigate('https://example.com')
// Get diagnostics
const errors = browser.getConsoleLogs({ type: 'error' })
const failed = browser.getNetworkLogs({ status: [400, 404, 500] })
const stats = browser.getNetworkStats()
await browser.close()
Full API: See index.ts for all methods.
VERIFY Phase Integration
MANDATORY for verifying web changes:
# Before claiming any web change is "live" or "working":
bun run Browse.ts https://example.com/changed-page
# Check the screenshot AND diagnostics
# If errors or failed requests exist, the change is NOT verified
If you haven't LOOKED at the rendered page and its diagnostics, you CANNOT claim it works.