@dannote/agent-browser

agent-browser

Headless browser automation CLI for AI agents. Fast Rust CLI with Node.js fallback.

Installation

npm (recommended)

npm install -g agent-browser
agent-browser install  # Download Chromium

From Source

git clone https://github.com/vercel-labs/agent-browser
cd agent-browser
pnpm install
pnpm build
pnpm build:native   # Requires Rust (https://rustup.rs)
pnpm link --global  # Makes agent-browser available globally
agent-browser install

Linux Dependencies

On Linux, install system dependencies:

agent-browser install --with-deps
# or manually: npx playwright install-deps chromium

Quick Start

agent-browser open example.com
agent-browser snapshot                    # Get accessibility tree with refs
agent-browser click @e2                   # Click by ref from snapshot
agent-browser fill @e3 "[e-mail]" # Fill by ref
agent-browser get text @e1                # Get text by ref
agent-browser screenshot page.png
agent-browser close

Traditional Selectors (also supported)

agent-browser click "#submit"
agent-browser fill "#email" "[e-mail]"
agent-browser find role button click --name "Submit"

Commands

Core Commands

agent-browser open <url>              # Navigate to URL (aliases: goto, navigate)
agent-browser click <sel>             # Click element
agent-browser dblclick <sel>          # Double-click element
agent-browser focus <sel>             # Focus element
agent-browser type <sel> <text>       # Type into element
agent-browser fill <sel> <text>       # Clear and fill
agent-browser press <key>             # Press key (Enter, Tab, Control+a) (alias: key)
agent-browser keydown <key>           # Hold key down
agent-browser keyup <key>             # Release key
agent-browser hover <sel>             # Hover element
agent-browser select <sel> <val>      # Select dropdown option
agent-browser check <sel>             # Check checkbox
agent-browser uncheck <sel>           # Uncheck checkbox
agent-browser scroll <dir> [px]       # Scroll (up/down/left/right)
agent-browser scrollintoview <sel>    # Scroll element into view (alias: scrollinto)
agent-browser drag <src> <tgt>        # Drag and drop
agent-browser upload <sel> <files>    # Upload files
agent-browser screenshot [path]       # Take screenshot (--full for full page, base64 png to stdout if no path)
agent-browser pdf <path>              # Save as PDF
agent-browser snapshot                # Accessibility tree with refs (best for AI)
agent-browser eval <js>               # Run JavaScript
agent-browser connect <port>          # Connect to browser via CDP
agent-browser close                   # Close browser (aliases: quit, exit)

Get Info

agent-browser get text <sel>          # Get text content
agent-browser get html <sel>          # Get innerHTML
agent-browser get value <sel>         # Get input value
agent-browser get attr <sel> <attr>   # Get attribute
agent-browser get title               # Get page title
agent-browser get url                 # Get current URL
agent-browser get count <sel>         # Count matching elements
agent-browser get box <sel>           # Get bounding box

Check State

agent-browser is visible <sel>        # Check if visible
agent-browser is enabled <sel>        # Check if enabled
agent-browser is checked <sel>        # Check if checked

Find Elements (Semantic Locators)

agent-browser find role <role> <action> [value]       # By ARIA role
agent-browser find text <text> <action>               # By text content
agent-browser find label <label> <action> [value]     # By label
agent-browser find placeholder <ph> <action> [value]  # By placeholder
agent-browser find alt <text> <action>                # By alt text
agent-browser find title <text> <action>              # By title attr
agent-browser find testid <id> <action> [value]       # By data-testid
agent-browser find first <sel> <action> [value]       # First match
agent-browser find last <sel> <action> [value]        # Last match
agent-browser find nth <n> <sel> <action> [value]     # Nth match

Actions: click, fill, check, hover, text

Examples:

agent-browser find role button click --name "Submit"
agent-browser find text "Sign In" click
agent-browser find label "Email" fill "[e-mail]"
agent-browser find first ".item" click
agent-browser find nth 2 "a" text

Wait

agent-browser wait <selector>         # Wait for element to be visible
agent-browser wait <ms>               # Wait for time (milliseconds)
agent-browser wait --text "Welcome"   # Wait for text to appear
agent-browser wait --url "**/dash"    # Wait for URL pattern
agent-browser wait --load networkidle # Wait for load state
agent-browser wait --fn "window.ready === true"  # Wait for JS condition

Load states: load, domcontentloaded, networkidle

Mouse Control

agent-browser mouse move <x> <y>      # Move mouse
agent-browser mouse down [button]     # Press button (left/right/middle)
agent-browser mouse up [button]       # Release button
agent-browser mouse wheel <dy> [dx]   # Scroll wheel

Browser Settings

agent-browser set viewport <w> <h>    # Set viewport size
agent-browser set device <name>       # Emulate device ("iPhone 14")
agent-browser set geo <lat> <lng>     # Set geolocation
agent-browser set offline [on|off]    # Toggle offline mode
agent-browser set headers <json>      # Extra HTTP headers
agent-browser set credentials <u> <p> # HTTP basic auth
agent-browser set media [dark|light]  # Emulate color scheme

Cookies & Storage

agent-browser cookies                 # Get all cookies
agent-browser cookies set <name> <val> # Set cookie
agent-browser cookies clear           # Clear cookies

agent-browser storage local           # Get all localStorage
agent-browser storage local <key>     # Get specific key
agent-browser storage local set <k> <v>  # Set value
agent-browser storage local clear     # Clear all

agent-browser storage session         # Same for sessionStorage

Network

agent-browser network route <url>              # Intercept requests
agent-browser network route <url> --abort      # Block requests
agent-browser network route <url> --body <json>  # Mock response
agent-browser network unroute [url]            # Remove routes
agent-browser network requests                 # View tracked requests
agent-browser network requests --filter api    # Filter requests

Tabs & Windows

agent-browser tab                     # List tabs
agent-browser tab new [url]           # New tab (optionally with URL)
agent-browser tab <n>                 # Switch to tab n
agent-browser tab close [n]           # Close tab
agent-browser window new              # New window

Frames

agent-browser frame <sel>             # Switch to iframe
agent-browser frame main              # Back to main frame

Dialogs

agent-browser dialog accept [text]    # Accept (with optional prompt text)
agent-browser dialog dismiss          # Dismiss

Debug

agent-browser trace start [path]      # Start recording trace
agent-browser trace stop [path]       # Stop and save trace
agent-browser console                 # View console messages
agent-browser console --clear         # Clear console
agent-browser errors                  # View page errors
agent-browser errors --clear          # Clear errors
agent-browser highlight <sel>         # Highlight element
agent-browser state save <path>       # Save auth state
agent-browser state load <path>       # Load auth state

Navigation

agent-browser back                    # Go back
agent-browser forward                 # Go forward
agent-browser reload                  # Reload page

Setup

agent-browser install                 # Download Chromium browser
agent-browser install --with-deps     # Also install system deps (Linux)

Sessions

Run multiple isolated browser instances:

# Different sessions
agent-browser --session agent1 open site-a.com
agent-browser --session agent2 open site-b.com

# Or via environment variable
AGENT_BROWSER_SESSION=agent1 agent-browser click "#btn"

# List active sessions
agent-browser session list
# Output:
# Active sessions:
# -> default
#    agent1

# Show current session
agent-browser session

Each session has its own:

• Browser instance
• Cookies and storage
• Navigation history
• Authentication state

Snapshot Options

The snapshot command supports filtering to reduce output size:

agent-browser snapshot                    # Full accessibility tree
agent-browser snapshot -i                 # Interactive elements only (buttons, inputs, links)
agent-browser snapshot -c                 # Compact (remove empty structural elements)
agent-browser snapshot -d 3               # Limit depth to 3 levels
agent-browser snapshot -s "#main"         # Scope to CSS selector
agent-browser snapshot -i -c -d 5         # Combine options

Option	Description
-i, --interactive	Only show interactive elements (buttons, links, inputs)
-c, --compact	Remove empty structural elements
-d, --depth <n>	Limit tree depth
-s, --selector <sel>	Scope to CSS selector

Options

Option	Description
--session <name>	Use isolated session (or AGENT_BROWSER_SESSION env)
--headers <json>	Set HTTP headers scoped to the URL's origin
--executable-path <path>	Custom browser executable (or AGENT_BROWSER_EXECUTABLE_PATH env)
--json	JSON output (for agents)
--full, -f	Full page screenshot
--name, -n	Locator name filter
--exact	Exact text match
--headed	Show browser window (not headless)
--cdp <port>	Connect via Chrome DevTools Protocol
--debug	Debug output

Selectors

Refs (Recommended for AI)

Refs provide deterministic element selection from snapshots:

# 1. Get snapshot with refs
agent-browser snapshot
# Output:
# - heading "Example Domain" [ref=e1] [level=1]
# - button "Submit" [ref=e2]
# - textbox "Email" [ref=e3]
# - link "Learn more" [ref=e4]

# 2. Use refs to interact
agent-browser click @e2                   # Click the button
agent-browser fill @e3 "[e-mail]" # Fill the textbox
agent-browser get text @e1                # Get heading text
agent-browser hover @e4                   # Hover the link

Why use refs?

• Deterministic: Ref points to exact element from snapshot
• Fast: No DOM re-query needed
• AI-friendly: Snapshot + ref workflow is optimal for LLMs

CSS Selectors

agent-browser click "#id"
agent-browser click ".class"
agent-browser click "div > button"

Text & XPath

agent-browser click "text=Submit"
agent-browser click "xpath=//button"

Semantic Locators

agent-browser find role button click --name "Submit"
agent-browser find label "Email" fill "[e-mail]"

Agent Mode

Use --json for machine-readable output:

agent-browser snapshot --json
# Returns: {"success":true,"data":{"snapshot":"...","refs":{"e1":{"role":"heading","name":"Title"},...}}}

agent-browser get text @e1 --json
agent-browser is visible @e2 --json

Optimal AI Workflow

# 1. Navigate and get snapshot
agent-browser open example.com
agent-browser snapshot -i --json   # AI parses tree and refs

# 2. AI identifies target refs from snapshot
# 3. Execute actions using refs
agent-browser click @e2
agent-browser fill @e3 "input text"

# 4. Get new snapshot if page changed
agent-browser snapshot -i --json

Headed Mode

Show the browser window for debugging:

agent-browser open example.com --headed

This opens a visible browser window instead of running headless.

Authenticated Sessions

Use --headers to set HTTP headers for a specific origin, enabling authentication without login flows:

# Headers are scoped to api.example.com only
agent-browser open api.example.com --headers '{"Authorization": "Bearer <token>"}'

# Requests to api.example.com include the auth header
agent-browser snapshot -i --json
agent-browser click @e2

# Navigate to another domain - headers are NOT sent (safe!)
agent-browser open other-site.com

This is useful for:

• Skipping login flows - Authenticate via headers instead of UI
• Switching users - Start new sessions with different auth tokens
• API testing - Access protected endpoints directly
• Security - Headers are scoped to the origin, not leaked to other domains

To set headers for multiple origins, use --headers with each open command:

agent-browser open api.example.com --headers '{"Authorization": "Bearer token1"}'
agent-browser open api.acme.com --headers '{"Authorization": "Bearer token2"}'

For global headers (all domains), use set headers:

agent-browser set headers '{"X-Custom-Header": "value"}'

Custom Browser Executable

Use a custom browser executable instead of the bundled Chromium. This is useful for:

• Serverless deployment: Use lightweight Chromium builds like @sparticuz/chromium (~50MB vs ~684MB)
• System browsers: Use an existing Chrome/Chromium installation
• Custom builds: Use modified browser builds

CLI Usage

# Via flag
agent-browser --executable-path /path/to/chromium open example.com

# Via environment variable
AGENT_BROWSER_EXECUTABLE_PATH=/path/to/chromium agent-browser open example.com

Serverless Example (Vercel/AWS Lambda)

import chromium from '@sparticuz/chromium';
import { BrowserManager } from 'agent-browser';

export async function handler() {
  const browser = new BrowserManager();
  await browser.launch({
    executablePath: await chromium.executablePath(),
    headless: true,
  });
  // ... use browser
}

CDP Mode

Connect to an existing browser via Chrome DevTools Protocol:

# Start Chrome with: google-chrome --remote-debugging-port=9222

# Connect once, then run commands without --cdp
agent-browser connect 9222
agent-browser snapshot
agent-browser tab
agent-browser close

# Or pass --cdp on each command
agent-browser --cdp 9222 snapshot

This enables control of:

• Electron apps
• Chrome/Chromium instances with remote debugging
• WebView2 applications
• Any browser exposing a CDP endpoint

Streaming (Browser Preview)

Stream the browser viewport via WebSocket for live preview or "pair browsing" where a human can watch and interact alongside an AI agent.

Enable Streaming

Set the AGENT_BROWSER_STREAM_PORT environment variable:

AGENT_BROWSER_STREAM_PORT=9223 agent-browser open example.com

This starts a WebSocket server on the specified port that streams the browser viewport and accepts input events.

WebSocket Protocol

Connect to ws://localhost:9223 to receive frames and send input:

Receive frames:

{
  "type": "frame",
  "data": "<base64-encoded-jpeg>",
  "metadata": {
    "deviceWidth": 1280,
    "deviceHeight": 720,
    "pageScaleFactor": 1,
    "offsetTop": 0,
    "scrollOffsetX": 0,
    "scrollOffsetY": 0
  }
}

Send mouse events:

{
  "type": "input_mouse",
  "eventType": "mousePressed",
  "x": 100,
  "y": 200,
  "button": "left",
  "clickCount": 1
}

Send keyboard events:

{
  "type": "input_keyboard",
  "eventType": "keyDown",
  "key": "Enter",
  "code": "Enter"
}

Send touch events:

{
  "type": "input_touch",
  "eventType": "touchStart",
  "touchPoints": [{ "x": 100, "y": 200 }]
}

Programmatic API

For advanced use, control streaming directly via the protocol:

import { BrowserManager } from 'agent-browser';

const browser = new BrowserManager();
await browser.launch({ headless: true });
await browser.navigate('https://example.com');

// Start screencast
await browser.startScreencast((frame) => {
  // frame.data is base64-encoded image
  // frame.metadata contains viewport info
  console.log('Frame received:', frame.metadata.deviceWidth, 'x', frame.metadata.deviceHeight);
}, {
  format: 'jpeg',
  quality: 80,
  maxWidth: 1280,
  maxHeight: 720,
});

// Inject mouse events
await browser.injectMouseEvent({
  type: 'mousePressed',
  x: 100,
  y: 200,
  button: 'left',
});

// Inject keyboard events
await browser.injectKeyboardEvent({
  type: 'keyDown',
  key: 'Enter',
  code: 'Enter',
});

// Stop when done
await browser.stopScreencast();

Architecture

agent-browser uses a client-daemon architecture:

• Rust CLI (fast native binary) - Parses commands, communicates with daemon
• Node.js Daemon - Manages Playwright browser instance
• Fallback - If native binary unavailable, uses Node.js directly

The daemon starts automatically on first command and persists between commands for fast subsequent operations.

Browser Engine: Uses Chromium by default. The daemon also supports Firefox and WebKit via the Playwright protocol.

Platforms

Platform	Binary	Fallback
macOS ARM64	Native Rust	Node.js
macOS x64	Native Rust	Node.js
Linux ARM64	Native Rust	Node.js
Linux x64	Native Rust	Node.js
Windows x64	Native Rust	Node.js

Usage with AI Agents

Just ask the agent

The simplest approach - just tell your agent to use it:

Use agent-browser to test the login flow. Run agent-browser --help to see available commands.

The --help output is comprehensive and most agents can figure it out from there.

AGENTS.md / CLAUDE.md

For more consistent results, add to your project or global instructions file:

## Browser Automation

Use `agent-browser` for web automation. Run `agent-browser --help` for all commands.

Core workflow:
1. `agent-browser open <url>` - Navigate to page
2. `agent-browser snapshot -i` - Get interactive elements with refs (@e1, @e2)
3. `agent-browser click @e1` / `fill @e2 "text"` - Interact using refs
4. Re-snapshot after page changes

Claude Code Skill

For Claude Code, a skill provides richer context:

cp -r node_modules/agent-browser/skills/agent-browser .claude/skills/

Or download:

mkdir -p .claude/skills/agent-browser
curl -o .claude/skills/agent-browser/SKILL.md \
  https://raw.githubusercontent.com/vercel-labs/agent-browser/main/skills/agent-browser/SKILL.md

License

Apache-2.0