Browser

Browser Automation

Browser automation via Vercel's agent-browser CLI. Runs headless by default; use --headed for visible window. Uses ref-based selection (@e1, @e2) from accessibility snapshots.

Setup

command -v agent-browser >/dev/null 2>&1 && echo "OK" || echo "MISSING: npm i -g agent-browser && agent-browser install"

Core Workflow

1. Open URL
2. Snapshot to get refs
3. Interact via refs
4. Re-snapshot after DOM changes

agent-browser open https://example.com
agent-browser snapshot -i              # Interactive elements with refs
agent-browser click @e1
agent-browser wait --load networkidle  # Wait for SPA to settle
agent-browser snapshot -i              # Re-snapshot after change

Essential Commands

Navigation

agent-browser open <url>       # Navigate
agent-browser back             # Go back
agent-browser forward          # Go forward
agent-browser reload           # Reload
agent-browser close            # Close browser

Snapshots

agent-browser snapshot           # Full accessibility tree
agent-browser snapshot -i        # Interactive only (recommended)
agent-browser snapshot -i --json # JSON for parsing
agent-browser snapshot -c        # Compact (remove empty)
agent-browser snapshot -d 3      # Limit depth
agent-browser snapshot -s "#main" # Scope to selector

Interactions

agent-browser click @e1              # Click
agent-browser dblclick @e1           # Double-click
agent-browser fill @e1 "text"        # Clear + fill input
agent-browser type @e1 "text"        # Type without clearing
agent-browser press Enter            # Key press
agent-browser press Control+a        # Key combination
agent-browser hover @e1              # Hover
agent-browser check @e1              # Check checkbox
agent-browser uncheck @e1            # Uncheck
agent-browser select @e1 "option"    # Dropdown
agent-browser scroll down 500        # Scroll direction + pixels
agent-browser scrollintoview @e1     # Scroll element visible

Get Info

agent-browser get text @e1       # Element text
agent-browser get value @e1      # Input value
agent-browser get html @e1       # Element HTML
agent-browser get attr href @e1  # Attribute
agent-browser get title          # Page title
agent-browser get url            # Current URL
agent-browser get count "button" # Count matches

Check State

agent-browser is visible @e1    # Check visibility
agent-browser is enabled @e1    # Check enabled
agent-browser is checked @e1    # Check checkbox state

Wait

agent-browser wait @e1                 # Wait for element visible
agent-browser wait 2000                # Wait milliseconds
agent-browser wait --text "Success"    # Wait for text
agent-browser wait --url "**/dashboard" # Wait for URL pattern
agent-browser wait --load networkidle  # Wait for network idle (SPAs)
agent-browser wait --fn "window.ready" # Wait for JS condition

Screenshots

agent-browser screenshot              # Viewport to stdout
agent-browser screenshot out.png      # Save to file
agent-browser screenshot --full       # Full page
agent-browser pdf out.pdf             # Save as PDF

Semantic Locators

Alternative when you know the element (no snapshot needed, see advanced.md for tabs, frames, network mocking):

agent-browser find role button click --name "Submit"
agent-browser find text "Sign In" click
agent-browser find label "Email" fill "user@test.com"
agent-browser find placeholder "Search" fill "query"
agent-browser find first ".item" click
agent-browser find nth 2 "a" text

Sessions

Parallel isolated browsers (see auth.md for multi-user auth):

agent-browser --session test1 open site-a.com
agent-browser --session test2 open site-b.com
agent-browser session list

JSON Output

Add --json for machine-readable output:

agent-browser snapshot -i --json
agent-browser get text @e1 --json
agent-browser is visible @e1 --json

Examples

Form Submission

agent-browser open https://example.com/form
agent-browser snapshot -i
# textbox "Email" [ref=e1], textbox "Password" [ref=e2], button "Submit" [ref=e3]
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  # Verify result

Auth with Saved State

# Login once
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

# Later: reuse saved auth
agent-browser state load auth.json
agent-browser open https://app.example.com/dashboard

More auth patterns in auth.md.

Token Auth (Skip Login)

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

Debugging

agent-browser --headed open example.com  # Show browser window
agent-browser console                    # View console messages
agent-browser errors                     # View page errors
agent-browser highlight @e1              # Highlight element

See debugging.md for traces, common issues.

Troubleshooting

"Browser not launched" error: Daemon stuck. Kill and retry:

pkill -f agent-browser && agent-browser open <url>

Element not found: Re-snapshot after page changes. DOM may have updated.

References