Browser Automation with agent-browser
Core Workflow
Every browser automation follows this pattern:
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Navigate: agent-browser open <url>
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Snapshot: agent-browser snapshot -i (get element refs like @e1 , @e2 )
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Interact: Use refs to click, fill, select
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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).
Essential Commands
Navigation
agent-browser open <url> # Navigate (aliases: goto, navigate) agent-browser close # Close browser
Snapshot
agent-browser snapshot -i # Interactive elements with refs (recommended) agent-browser snapshot -i -C # Include cursor-interactive elements (divs with onclick, cursor:pointer) 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
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
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
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 pdf output.pdf # Save as PDF
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
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
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
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
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
Visual Browser (Debugging)
agent-browser --headed open https://example.com agent-browser highlight @e1 # Highlight element 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 Playwright timeout is 25 seconds for local browsers. 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 .
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
If a previous session was not closed properly, the daemon may still be running. Use agent-browser close to clean it up before starting new work.
Ref Lifecycle (Important)
Refs (@e1 , @e2 , etc.) are invalidated when the page changes. Always re-snapshot after:
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Clicking links or buttons that navigate
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Form submissions
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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:
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The page has unlabeled icon buttons or visual-only elements
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You need to verify visual layout or styling
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Canvas or chart elements are present (invisible to text snapshots)
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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:
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Single-line, no nested quotes -> regular eval 'expression' with single quotes is fine
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Nested quotes, arrow functions, template literals, or multiline -> use eval --stdin <<'EVALEOF'
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Programmatic/generated scripts -> use eval -b with base64
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
Experimental: Native Mode
agent-browser has an experimental native Rust daemon that communicates with Chrome directly via CDP, bypassing Node.js and Playwright entirely. It is opt-in and not recommended for production use yet.
Enable via flag
agent-browser --native open example.com
Enable via environment variable (avoids passing --native every time)
export AGENT_BROWSER_NATIVE=1 agent-browser open example.com
The native daemon supports Chromium and Safari (via WebDriver). Firefox and WebKit are not yet supported. All core commands (navigate, snapshot, click, fill, screenshot, cookies, storage, tabs, eval, etc.) work identically in native mode. Use agent-browser close before switching between native and default mode within the same session.
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