Browser 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. Run

agent-browser upgrade

to update to the latest version.

Core Workflow

Every browser automation follows this pattern:

Navigate:
```
agent-browser open <url>
```
Snapshot:
```
agent-browser snapshot -i
```
(get element refs like
```
@e1
```
,
```
@e2
```
)
Interact: Use refs to click, fill, select
Re-snapshot: After navigation or DOM changes, get fresh refs

bash

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.

bash

# 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)

bash

# 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)

bash

# 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)

bash

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)

bash

echo "$PASSWORD" | agent-browser auth save myapp --url https://app.example.com/login --username user --password-stdin
agent-browser auth login myapp

Option 5: State file (manual save/load)

bash

# 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

bash

# 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
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 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

# 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

# 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

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.

bash

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

bash

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)

bash

# 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

bash

# 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

bash

# 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.

bash

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

bash

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

bash

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

bash

# 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)

bash

# 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

bash

# 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)

bash

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)

bash

# 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)

bash

# 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:

bash

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:

bash

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:

bash

export AGENT_BROWSER_ACTION_POLICY=./policy.json

Example

policy.json

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:

bash

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.

bash

# 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:

bash

# 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:

bash

# 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>

wait @ref

Session Management and Cleanup

When running multiple agents or automations concurrently, always use named sessions to avoid conflicts:

bash

# 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:

bash

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.

To auto-shutdown the daemon after a period of inactivity (useful for ephemeral/CI environments):

bash

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)

bash

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.

bash

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:

bash

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

-b

to avoid issues.

bash

# 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
```
eval 'expression'
```
with single quotes is fine
Nested quotes, arrow functions, template literals, or multiline -> use
```
eval --stdin <<'EVALEOF'
```
Programmatic/generated scripts -> use
```
eval -b
```
with base64

Configuration File

Create

agent-browser.json

in the project root for persistent settings:

json

{
  "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>

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

bash

# 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:

```
chrome
```
(default) -- Chrome/Chromium via CDP
```
lightpanda
```
-- Lightpanda headless browser via CDP (10x faster, 10x less memory than Chrome)

Lightpanda does not support

--extension

--profile

--state

, or

--allow-file-access

. Install Lightpanda from https://lightpanda.io/docs/open-source/installation.

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

bash

./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

agent-browser

NPX Install

SKILL.md Content

Browser Automation with agent-browser

Core Workflow

Command Chaining

Handling Authentication

Essential Commands

Batch Execution

Common Patterns

Form Submission

Authentication with Auth Vault (Recommended)

Authentication with State Persistence

Session Persistence

Working with Iframes

Data Extraction

Parallel Sessions

Connect to Existing Chrome

Color Scheme (Dark Mode)

Viewport & Responsive Testing

Visual Browser (Debugging)

Local Files (PDFs, HTML)

iOS Simulator (Mobile Safari)

Security

Content Boundaries (Recommended for AI Agents)

Domain Allowlist

Action Policy

Output Limits

Diffing (Verifying Changes)

Timeouts and Slow Pages

Session Management and Cleanup

Ref Lifecycle (Important)

Annotated Screenshots (Vision Mode)

Semantic Locators (Alternative to Refs)

JavaScript Evaluation (eval)

Configuration File

Deep-Dive Documentation

Browser Engine Selection

Ready-to-Use Templates