Claude-codex-settings agent-browser
Browser automation CLI for AI agents. Use when the user needs to interact with websites, including navigating pages, filling forms, clicking buttons, taking screenshots, extracting data, testing web apps, or automating any browser task. Triggers include requests to "open a website", "fill out a form", "click a button", "take a screenshot", "scrape data from a page", "test this web app", "login to a site", "automate browser actions", or any task requiring programmatic web interaction.
git clone https://github.com/fcakyon/claude-codex-settings
T=$(mktemp -d) && git clone --depth=1 https://github.com/fcakyon/claude-codex-settings "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/agent-browser/skills/agent-browser" ~/.claude/skills/fcakyon-claude-codex-settings-agent-browser && rm -rf "$T"
plugins/agent-browser/skills/agent-browser/SKILL.mdBrowser Automation with agent-browser
The CLI uses Chrome/Chromium via CDP directly. Install via
npm i -g agent-browser, brew install agent-browser, or cargo install agent-browser. Run agent-browser install to download Chrome. Existing Chrome, Brave, Playwright, and Puppeteer installations are detected automatically. Run agent-browser upgrade to update to the latest version.
Core Workflow
Every browser automation follows this pattern:
- Navigate:
agent-browser open <url> - Snapshot:
(get element refs likeagent-browser snapshot -i
,@e1
)@e2 - Interact: Use refs to click, fill, select
- Re-snapshot: After navigation or DOM changes, get fresh refs
agent-browser open https://example.com/form agent-browser snapshot -i # Output: @e1 [input type="email"], @e2 [input type="password"], @e3 [button] "Submit" agent-browser fill @e1 "user@example.com" agent-browser fill @e2 "password123" agent-browser click @e3 agent-browser wait --load networkidle agent-browser snapshot -i # Check result
Command Chaining
Commands can be chained with
&& in a single shell invocation. The browser persists between commands via a background daemon, so chaining is safe and more efficient than separate calls.
# Chain open + wait + snapshot in one call agent-browser open https://example.com && agent-browser wait --load networkidle && agent-browser snapshot -i # Chain multiple interactions agent-browser fill @e1 "user@example.com" && agent-browser fill @e2 "password123" && agent-browser click @e3 # Navigate and capture agent-browser open https://example.com && agent-browser wait --load networkidle && agent-browser screenshot page.png
When to chain: Use
&& when you don't need to read the output of an intermediate command before proceeding (e.g., open + wait + screenshot). Run commands separately when you need to parse the output first (e.g., snapshot to discover refs, then interact using those refs).
Handling Authentication
When automating a site that requires login, choose the approach that fits:
Option 1: Import auth from the user's browser (fastest for one-off tasks)
# Connect to the user's running Chrome (they're already logged in) agent-browser --auto-connect state save ./auth.json # Use that auth state agent-browser --state ./auth.json open https://app.example.com/dashboard
State files contain session tokens in plaintext -- add to
.gitignore and delete when no longer needed. Set AGENT_BROWSER_ENCRYPTION_KEY for encryption at rest.
Option 2: Persistent profile (simplest for recurring tasks)
# First run: login manually or via automation agent-browser --profile ~/.myapp open https://app.example.com/login # ... fill credentials, submit ... # All future runs: already authenticated agent-browser --profile ~/.myapp open https://app.example.com/dashboard
Option 3: Session name (auto-save/restore cookies + localStorage)
agent-browser --session-name myapp open https://app.example.com/login # ... login flow ... agent-browser close # State auto-saved # Next time: state auto-restored agent-browser --session-name myapp open https://app.example.com/dashboard
Option 4: Auth vault (credentials stored encrypted, login by name)
echo "$PASSWORD" | agent-browser auth save myapp --url https://app.example.com/login --username user --password-stdin agent-browser auth login myapp
auth login navigates with load and then waits for login form selectors to appear before filling/clicking, which is more reliable on delayed SPA login screens.
Option 5: State file (manual save/load)
# After logging in: agent-browser state save ./auth.json # In a future session: agent-browser state load ./auth.json agent-browser open https://app.example.com/dashboard
See references/authentication.md for OAuth, 2FA, cookie-based auth, and token refresh patterns.
Essential Commands
# Navigation agent-browser open <url> # Navigate (aliases: goto, navigate) agent-browser close # Close browser agent-browser close --all # Close all active sessions # Snapshot agent-browser snapshot -i # Interactive elements with refs (recommended) agent-browser snapshot -s "#selector" # Scope to CSS selector # Interaction (use @refs from snapshot) agent-browser click @e1 # Click element agent-browser click @e1 --new-tab # Click and open in new tab agent-browser fill @e2 "text" # Clear and type text agent-browser type @e2 "text" # Type without clearing agent-browser select @e1 "option" # Select dropdown option agent-browser check @e1 # Check checkbox agent-browser press Enter # Press key agent-browser keyboard type "text" # Type at current focus (no selector) agent-browser keyboard inserttext "text" # Insert without key events agent-browser scroll down 500 # Scroll page agent-browser scroll down 500 --selector "div.content" # Scroll within a specific container # Get information agent-browser get text @e1 # Get element text agent-browser get url # Get current URL agent-browser get title # Get page title agent-browser get cdp-url # Get CDP WebSocket URL # Wait agent-browser wait @e1 # Wait for element agent-browser wait --load networkidle # Wait for network idle agent-browser wait --url "**/page" # Wait for URL pattern agent-browser wait 2000 # Wait milliseconds agent-browser wait --text "Welcome" # Wait for text to appear (substring match) agent-browser wait --fn "!document.body.innerText.includes('Loading...')" # Wait for text to disappear agent-browser wait "#spinner" --state hidden # Wait for element to disappear # Downloads agent-browser download @e1 ./file.pdf # Click element to trigger download agent-browser wait --download ./output.zip # Wait for any download to complete agent-browser --download-path ./downloads open <url> # Set default download directory # Network agent-browser network requests # Inspect tracked requests agent-browser network requests --type xhr,fetch # Filter by resource type agent-browser network requests --method POST # Filter by HTTP method agent-browser network requests --status 2xx # Filter by status (200, 2xx, 400-499) agent-browser network request <requestId> # View full request/response detail agent-browser network route "**/api/*" --abort # Block matching requests agent-browser network har start # Start HAR recording agent-browser network har stop ./capture.har # Stop and save HAR file # Viewport & Device Emulation agent-browser set viewport 1920 1080 # Set viewport size (default: 1280x720) agent-browser set viewport 1920 1080 2 # 2x retina (same CSS size, higher res screenshots) agent-browser set device "iPhone 14" # Emulate device (viewport + user agent) # Capture agent-browser screenshot # Screenshot to temp dir agent-browser screenshot --full # Full page screenshot agent-browser screenshot --annotate # Annotated screenshot with numbered element labels agent-browser screenshot --screenshot-dir ./shots # Save to custom directory agent-browser screenshot --screenshot-format jpeg --screenshot-quality 80 agent-browser pdf output.pdf # Save as PDF # Live preview / streaming agent-browser stream enable # Start runtime WebSocket streaming on an auto-selected port agent-browser stream enable --port 9223 # Bind a specific localhost port agent-browser stream status # Inspect enabled state, port, connection, and screencasting agent-browser stream disable # Stop runtime streaming and remove the .stream metadata file # Clipboard agent-browser clipboard read # Read text from clipboard agent-browser clipboard write "Hello, World!" # Write text to clipboard agent-browser clipboard copy # Copy current selection agent-browser clipboard paste # Paste from clipboard # Dialogs (alert, confirm, prompt, beforeunload) # By default, alert and beforeunload dialogs are auto-accepted so they never block the agent. # confirm and prompt dialogs still require explicit handling. # Use --no-auto-dialog (or AGENT_BROWSER_NO_AUTO_DIALOG=1) to disable automatic handling. agent-browser dialog accept # Accept dialog agent-browser dialog accept "my input" # Accept prompt dialog with text agent-browser dialog dismiss # Dismiss/cancel dialog agent-browser dialog status # Check if a dialog is currently open # Diff (compare page states) agent-browser diff snapshot # Compare current vs last snapshot agent-browser diff snapshot --baseline before.txt # Compare current vs saved file agent-browser diff screenshot --baseline before.png # Visual pixel diff agent-browser diff url <url1> <url2> # Compare two pages agent-browser diff url <url1> <url2> --wait-until networkidle # Custom wait strategy agent-browser diff url <url1> <url2> --selector "#main" # Scope to element
Streaming
Every session automatically starts a WebSocket stream server on an OS-assigned port. Use
agent-browser stream status to see the bound port and connection state. Use stream disable to tear it down, and stream enable --port <port> to re-enable on a specific port.
Batch Execution
Execute multiple commands in a single invocation by piping a JSON array of string arrays to
batch. This avoids per-command process startup overhead when running multi-step workflows.
echo '[ ["open", "https://example.com"], ["snapshot", "-i"], ["click", "@e1"], ["screenshot", "result.png"] ]' | agent-browser batch --json # Stop on first error agent-browser batch --bail < commands.json
Use
batch when you have a known sequence of commands that don't depend on intermediate output. Use separate commands or && chaining when you need to parse output between steps (e.g., snapshot to discover refs, then interact).
Common Patterns
Form Submission
agent-browser open https://example.com/signup agent-browser snapshot -i agent-browser fill @e1 "Jane Doe" agent-browser fill @e2 "jane@example.com" agent-browser select @e3 "California" agent-browser check @e4 agent-browser click @e5 agent-browser wait --load networkidle
Authentication with Auth Vault (Recommended)
# Save credentials once (encrypted with AGENT_BROWSER_ENCRYPTION_KEY) # Recommended: pipe password via stdin to avoid shell history exposure echo "pass" | agent-browser auth save github --url https://github.com/login --username user --password-stdin # Login using saved profile (LLM never sees password) agent-browser auth login github # List/show/delete profiles agent-browser auth list agent-browser auth show github agent-browser auth delete github
auth login waits for username/password/submit selectors before interacting, with a timeout tied to the default action timeout.
Authentication with State Persistence
# Login once and save state agent-browser open https://app.example.com/login agent-browser snapshot -i agent-browser fill @e1 "$USERNAME" agent-browser fill @e2 "$PASSWORD" agent-browser click @e3 agent-browser wait --url "**/dashboard" agent-browser state save auth.json # Reuse in future sessions agent-browser state load auth.json agent-browser open https://app.example.com/dashboard
Session Persistence
# Auto-save/restore cookies and localStorage across browser restarts agent-browser --session-name myapp open https://app.example.com/login # ... login flow ... agent-browser close # State auto-saved to ~/.agent-browser/sessions/ # Next time, state is auto-loaded agent-browser --session-name myapp open https://app.example.com/dashboard # Encrypt state at rest export AGENT_BROWSER_ENCRYPTION_KEY=$(openssl rand -hex 32) agent-browser --session-name secure open https://app.example.com # Manage saved states agent-browser state list agent-browser state show myapp-default.json agent-browser state clear myapp agent-browser state clean --older-than 7
Working with Iframes
Iframe content is automatically inlined in snapshots. Refs inside iframes carry frame context, so you can interact with them directly.
agent-browser open https://example.com/checkout agent-browser snapshot -i # @e1 [heading] "Checkout" # @e2 [Iframe] "payment-frame" # @e3 [input] "Card number" # @e4 [input] "Expiry" # @e5 [button] "Pay" # Interact directly — no frame switch needed agent-browser fill @e3 "4111111111111111" agent-browser fill @e4 "12/28" agent-browser click @e5 # To scope a snapshot to one iframe: agent-browser frame @e2 agent-browser snapshot -i # Only iframe content agent-browser frame main # Return to main frame
Data Extraction
agent-browser open https://example.com/products agent-browser snapshot -i agent-browser get text @e5 # Get specific element text agent-browser get text body > page.txt # Get all page text # JSON output for parsing agent-browser snapshot -i --json agent-browser get text @e1 --json
Parallel Sessions
agent-browser --session site1 open https://site-a.com agent-browser --session site2 open https://site-b.com agent-browser --session site1 snapshot -i agent-browser --session site2 snapshot -i agent-browser session list
Connect to Existing Chrome
# Auto-discover running Chrome with remote debugging enabled agent-browser --auto-connect open https://example.com agent-browser --auto-connect snapshot # Or with explicit CDP port agent-browser --cdp 9222 snapshot
Auto-connect discovers Chrome via
DevToolsActivePort, common debugging ports (9222, 9229), and falls back to a direct WebSocket connection if HTTP-based CDP discovery fails.
Color Scheme (Dark Mode)
# Persistent dark mode via flag (applies to all pages and new tabs) agent-browser --color-scheme dark open https://example.com # Or via environment variable AGENT_BROWSER_COLOR_SCHEME=dark agent-browser open https://example.com # Or set during session (persists for subsequent commands) agent-browser set media dark
Viewport & Responsive Testing
# Set a custom viewport size (default is 1280x720) agent-browser set viewport 1920 1080 agent-browser screenshot desktop.png # Test mobile-width layout agent-browser set viewport 375 812 agent-browser screenshot mobile.png # Retina/HiDPI: same CSS layout at 2x pixel density # Screenshots stay at logical viewport size, but content renders at higher DPI agent-browser set viewport 1920 1080 2 agent-browser screenshot retina.png # Device emulation (sets viewport + user agent in one step) agent-browser set device "iPhone 14" agent-browser screenshot device.png
The
scale parameter (3rd argument) sets window.devicePixelRatio without changing CSS layout. Use it when testing retina rendering or capturing higher-resolution screenshots.
Visual Browser (Debugging)
agent-browser --headed open https://example.com agent-browser highlight @e1 # Highlight element agent-browser inspect # Open Chrome DevTools for the active page agent-browser record start demo.webm # Record session agent-browser profiler start # Start Chrome DevTools profiling agent-browser profiler stop trace.json # Stop and save profile (path optional)
Use
AGENT_BROWSER_HEADED=1 to enable headed mode via environment variable. Browser extensions work in both headed and headless mode.
Local Files (PDFs, HTML)
# Open local files with file:// URLs agent-browser --allow-file-access open file:///path/to/document.pdf agent-browser --allow-file-access open file:///path/to/page.html agent-browser screenshot output.png
iOS Simulator (Mobile Safari)
# List available iOS simulators agent-browser device list # Launch Safari on a specific device agent-browser -p ios --device "iPhone 16 Pro" open https://example.com # Same workflow as desktop - snapshot, interact, re-snapshot agent-browser -p ios snapshot -i agent-browser -p ios tap @e1 # Tap (alias for click) agent-browser -p ios fill @e2 "text" agent-browser -p ios swipe up # Mobile-specific gesture # Take screenshot agent-browser -p ios screenshot mobile.png # Close session (shuts down simulator) agent-browser -p ios close
Requirements: macOS with Xcode, Appium (
npm install -g appium && appium driver install xcuitest)
Real devices: Works with physical iOS devices if pre-configured. Use
--device "<UDID>" where UDID is from xcrun xctrace list devices.
Security
All security features are opt-in. By default, agent-browser imposes no restrictions on navigation, actions, or output.
Content Boundaries (Recommended for AI Agents)
Enable
--content-boundaries to wrap page-sourced output in markers that help LLMs distinguish tool output from untrusted page content:
export AGENT_BROWSER_CONTENT_BOUNDARIES=1 agent-browser snapshot # Output: # --- AGENT_BROWSER_PAGE_CONTENT nonce=<hex> origin=https://example.com --- # [accessibility tree] # --- END_AGENT_BROWSER_PAGE_CONTENT nonce=<hex> ---
Domain Allowlist
Restrict navigation to trusted domains. Wildcards like
*.example.com also match the bare domain example.com. Sub-resource requests, WebSocket, and EventSource connections to non-allowed domains are also blocked. Include CDN domains your target pages depend on:
export AGENT_BROWSER_ALLOWED_DOMAINS="example.com,*.example.com" agent-browser open https://example.com # OK agent-browser open https://malicious.com # Blocked
Action Policy
Use a policy file to gate destructive actions:
export AGENT_BROWSER_ACTION_POLICY=./policy.json
Example
policy.json:
{ "default": "deny", "allow": ["navigate", "snapshot", "click", "scroll", "wait", "get"] }
Auth vault operations (
auth login, etc.) bypass action policy but domain allowlist still applies.
Output Limits
Prevent context flooding from large pages:
export AGENT_BROWSER_MAX_OUTPUT=50000
Diffing (Verifying Changes)
Use
diff snapshot after performing an action to verify it had the intended effect. This compares the current accessibility tree against the last snapshot taken in the session.
# Typical workflow: snapshot -> action -> diff agent-browser snapshot -i # Take baseline snapshot agent-browser click @e2 # Perform action agent-browser diff snapshot # See what changed (auto-compares to last snapshot)
For visual regression testing or monitoring:
# Save a baseline screenshot, then compare later agent-browser screenshot baseline.png # ... time passes or changes are made ... agent-browser diff screenshot --baseline baseline.png # Compare staging vs production agent-browser diff url https://staging.example.com https://prod.example.com --screenshot
diff snapshot output uses + for additions and - for removals, similar to git diff. diff screenshot produces a diff image with changed pixels highlighted in red, plus a mismatch percentage.
Timeouts and Slow Pages
The default timeout is 25 seconds. This can be overridden with the
AGENT_BROWSER_DEFAULT_TIMEOUT environment variable (value in milliseconds). For slow websites or large pages, use explicit waits instead of relying on the default timeout:
# Wait for network activity to settle (best for slow pages) agent-browser wait --load networkidle # Wait for a specific element to appear agent-browser wait "#content" agent-browser wait @e1 # Wait for a specific URL pattern (useful after redirects) agent-browser wait --url "**/dashboard" # Wait for a JavaScript condition agent-browser wait --fn "document.readyState === 'complete'" # Wait a fixed duration (milliseconds) as a last resort agent-browser wait 5000
When dealing with consistently slow websites, use
wait --load networkidle after open to ensure the page is fully loaded before taking a snapshot. If a specific element is slow to render, wait for it directly with wait <selector> or wait @ref.
JavaScript Dialogs (alert / confirm / prompt)
When a page opens a JavaScript dialog (
alert(), confirm(), or prompt()), it blocks all other browser commands (snapshot, screenshot, click, etc.) until the dialog is dismissed. If commands start timing out unexpectedly, check for a pending dialog:
# Check if a dialog is blocking agent-browser dialog status # Accept the dialog (dismiss the alert / click OK) agent-browser dialog accept # Accept a prompt dialog with input text agent-browser dialog accept "my input" # Dismiss the dialog (click Cancel) agent-browser dialog dismiss
When a dialog is pending, all command responses include a
warning field indicating the dialog type and message. In --json mode this appears as a "warning" key in the response object.
Session Management and Cleanup
When running multiple agents or automations concurrently, always use named sessions to avoid conflicts:
# Each agent gets its own isolated session agent-browser --session agent1 open site-a.com agent-browser --session agent2 open site-b.com # Check active sessions agent-browser session list
Always close your browser session when done to avoid leaked processes:
agent-browser close # Close default session agent-browser --session agent1 close # Close specific session agent-browser close --all # Close all active sessions
If a previous session was not closed properly, the daemon may still be running. Use
agent-browser close to clean it up, or agent-browser close --all to shut down every session at once.
To auto-shutdown the daemon after a period of inactivity (useful for ephemeral/CI environments):
AGENT_BROWSER_IDLE_TIMEOUT_MS=60000 agent-browser open example.com
Ref Lifecycle (Important)
Refs (
@e1, @e2, etc.) are invalidated when the page changes. Always re-snapshot after:
- Clicking links or buttons that navigate
- Form submissions
- Dynamic content loading (dropdowns, modals)
agent-browser click @e5 # Navigates to new page agent-browser snapshot -i # MUST re-snapshot agent-browser click @e1 # Use new refs
Annotated Screenshots (Vision Mode)
Use
--annotate to take a screenshot with numbered labels overlaid on interactive elements. Each label [N] maps to ref @eN. This also caches refs, so you can interact with elements immediately without a separate snapshot.
agent-browser screenshot --annotate # Output includes the image path and a legend: # [1] @e1 button "Submit" # [2] @e2 link "Home" # [3] @e3 textbox "Email" agent-browser click @e2 # Click using ref from annotated screenshot
Use annotated screenshots when:
- The page has unlabeled icon buttons or visual-only elements
- You need to verify visual layout or styling
- Canvas or chart elements are present (invisible to text snapshots)
- You need spatial reasoning about element positions
Semantic Locators (Alternative to Refs)
When refs are unavailable or unreliable, use semantic locators:
agent-browser find text "Sign In" click agent-browser find label "Email" fill "user@test.com" agent-browser find role button click --name "Submit" agent-browser find placeholder "Search" type "query" agent-browser find testid "submit-btn" click
JavaScript Evaluation (eval)
Use
eval to run JavaScript in the browser context. Shell quoting can corrupt complex expressions -- use --stdin or -b to avoid issues.
# Simple expressions work with regular quoting agent-browser eval 'document.title' agent-browser eval 'document.querySelectorAll("img").length' # Complex JS: use --stdin with heredoc (RECOMMENDED) agent-browser eval --stdin <<'EVALEOF' JSON.stringify( Array.from(document.querySelectorAll("img")) .filter(i => !i.alt) .map(i => ({ src: i.src.split("/").pop(), width: i.width })) ) EVALEOF # Alternative: base64 encoding (avoids all shell escaping issues) agent-browser eval -b "$(echo -n 'Array.from(document.querySelectorAll("a")).map(a => a.href)' | base64)"
Why this matters: When the shell processes your command, inner double quotes,
! characters (history expansion), backticks, and $() can all corrupt the JavaScript before it reaches agent-browser. The --stdin and -b flags bypass shell interpretation entirely.
Rules of thumb:
- Single-line, no nested quotes -> regular
with single quotes is fineeval 'expression' - Nested quotes, arrow functions, template literals, or multiline -> use
eval --stdin <<'EVALEOF' - Programmatic/generated scripts -> use
with base64eval -b
Configuration File
Create
agent-browser.json in the project root for persistent settings:
{ "headed": true, "proxy": "http://localhost:8080", "profile": "./browser-data" }
Priority (lowest to highest):
~/.agent-browser/config.json < ./agent-browser.json < env vars < CLI flags. Use --config <path> or AGENT_BROWSER_CONFIG env var for a custom config file (exits with error if missing/invalid). All CLI options map to camelCase keys (e.g., --executable-path -> "executablePath"). Boolean flags accept true/false values (e.g., --headed false overrides config). Extensions from user and project configs are merged, not replaced.
Deep-Dive Documentation
| Reference | When to Use |
|---|---|
| references/commands.md | Full command reference with all options |
| references/snapshot-refs.md | Ref lifecycle, invalidation rules, troubleshooting |
| references/session-management.md | Parallel sessions, state persistence, concurrent scraping |
| references/authentication.md | Login flows, OAuth, 2FA handling, state reuse |
| references/video-recording.md | Recording workflows for debugging and documentation |
| references/profiling.md | Chrome DevTools profiling for performance analysis |
| references/proxy-support.md | Proxy configuration, geo-testing, rotating proxies |
Browser Engine Selection
Use
--engine to choose a local browser engine. The default is chrome.
# Use Lightpanda (fast headless browser, requires separate install) agent-browser --engine lightpanda open example.com # Via environment variable export AGENT_BROWSER_ENGINE=lightpanda agent-browser open example.com # With custom binary path agent-browser --engine lightpanda --executable-path /path/to/lightpanda open example.com
Supported engines:
(default) -- Chrome/Chromium via CDPchrome
-- Lightpanda headless browser via CDP (10x faster, 10x less memory than Chrome)lightpanda
Lightpanda does not support
--extension, --profile, --state, or --allow-file-access. Install Lightpanda from https://lightpanda.io/docs/open-source/installation.
Observability Dashboard
The dashboard is a standalone background server that shows live browser viewports, command activity, and console output for all sessions.
# Install the dashboard once agent-browser dashboard install # Start the dashboard server (background, port 4848) agent-browser dashboard start # All sessions are automatically visible in the dashboard agent-browser open example.com # Stop the dashboard agent-browser dashboard stop
The dashboard runs independently of browser sessions on port 4848 (configurable with
--port). All sessions automatically stream to the dashboard. Sessions can also be created from the dashboard UI with local engines or cloud providers.
Ready-to-Use Templates
| Template | Description |
|---|---|
| templates/form-automation.sh | Form filling with validation |
| templates/authenticated-session.sh | Login once, reuse state |
| templates/capture-workflow.sh | Content extraction with screenshots |
./templates/form-automation.sh https://example.com/form ./templates/authenticated-session.sh https://app.example.com/login ./templates/capture-workflow.sh https://example.com ./output