agent-browser

name

agent-browser

description

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", or any task requiring web interaction.

Browser Automation with agent-browser

agent-browser is a CLI tool for browser automation. It runs a persistent browser daemon and provides commands to navigate, snapshot, and interact with web pages.

Prerequisites

npm install -g agent-browser
# or use npx (auto-installs on first use)

Core Workflow

Every browser automation follows this pattern:

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

agent-browser open https://example.com/form
agent-browser snapshot -i
# Output shows refs: @e1 [input "email"], @e2 [input "password"], @e3 [button "Submit"]

agent-browser fill @e1 "[e-mail]"
agent-browser fill @e2 "password123"
agent-browser click @e3
agent-browser wait --load networkidle
agent-browser snapshot -i  # Check result

Essential Commands

# Navigation
agent-browser open <url>              # Navigate to URL
agent-browser close                   # Close browser

# Snapshot (get element refs)
agent-browser snapshot -i             # Interactive elements with refs
agent-browser snapshot -i -C          # Include cursor-interactive elements

# Interaction (use @refs from snapshot)
agent-browser click @e1               # Click element
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 scroll down 500         # Scroll page

# 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

# Capture
agent-browser screenshot              # Screenshot to temp dir
agent-browser screenshot --full       # Full page screenshot
agent-browser pdf output.pdf          # Save as PDF

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 "[e-mail]"
agent-browser select @e3 "California"
agent-browser check @e4
agent-browser click @e5
agent-browser wait --load networkidle

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

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

Command Chaining

Commands can be chained when you don't need intermediate output:

agent-browser open https://example.com && agent-browser wait --load networkidle && agent-browser snapshot -i

Run commands separately when you need to read output first (e.g., snapshot to discover refs, then interact using those refs).

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 for new refs
agent-browser click @e1              # Use new refs

Session Management

# Named sessions for isolation
agent-browser --session site1 open https://site-a.com
agent-browser --session site2 open https://site-b.com

# Always close when done
agent-browser close

Security

All security features are opt-in:

# Domain allowlist
export AGENT_BROWSER_ALLOWED_DOMAINS="example.com,*.example.com"

# Content boundaries (prevents prompt injection)
export AGENT_BROWSER_CONTENT_BOUNDARIES=1

# Output limits
export AGENT_BROWSER_MAX_OUTPUT=50000