agent-browser · git:20260529.0ab6ab0 · 2026-05-29 · sha256 3785c22341d65213
agent-browser git:20260529.0ab6ab0A
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---
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", "automate browser actions", or any task requiring programmatic web interaction.
allowed-tools: bash
license: Apache-2.0
metadata:
source: https://github.com/vercel-labs/agent-browser
author: vercel-labs
origin: ported from agent-browser CLI documentation
---
# 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.
## 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
```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
Choose the approach that fits. See [references/authentication.md](references/authentication.md) for full details including OAuth, 2FA, and token refresh.
| Approach | When | Command |
|---|---|---|
| Auth vault | Recurring tasks, password never exposed to LLM | `echo "$PW" \| agent-browser auth save myapp --url <url> --username user --password-stdin` then `agent-browser auth login myapp` |
| Session name | Auto-save/restore cookies across restarts | `agent-browser --session-name myapp open <url>` |
| Persistent profile | Full browser profile reuse | `agent-browser --profile ~/.myapp open <url>` |
| Import from user browser | One-off tasks, user already logged in | `agent-browser --auto-connect state save ./auth.json` then `agent-browser --state ./auth.json open <url>` |
| State file | Manual save/load | `agent-browser state save auth.json` / `agent-browser state load auth.json` |
State files contain session tokens in plaintext -- add to `.gitignore` and set `AGENT_BROWSER_ENCRYPTION_KEY` for encryption at rest.
## Essential Commands
For the full command reference with all options, see [references/commands.md](references/commands.md).
```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
agent-browser snapshot -s "#selector" # Scope to CSS selector
# 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
# 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 --text "Welcome" # Wait for text to appear
agent-browser wait "#spinner" --state hidden # Wait for element to disappear
# Capture
agent-browser screenshot # Screenshot to temp dir
agent-browser screenshot --full # Full page screenshot
agent-browser screenshot --annotate # Annotated 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 screenshot --baseline before.png # Visual pixel diff
```
## Common Patterns
### 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
```
### Color Scheme (Dark Mode)
```bash
agent-browser --color-scheme dark open https://example.com # Flag
AGENT_BROWSER_COLOR_SCHEME=dark agent-browser open https://example.com # Env var
agent-browser set media dark # During session
```
### Viewport & Responsive Testing
```bash
agent-browser set viewport 1920 1080 # Desktop
agent-browser set viewport 375 812 # Mobile
agent-browser set viewport 1920 1080 2 # Retina (3rd arg = devicePixelRatio)
agent-browser set device "iPhone 14" # Device emulation (viewport + UA)
```
### 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
agent-browser -p ios --device "iPhone 16 Pro" open https://example.com
agent-browser -p ios snapshot -i && agent-browser -p ios tap @e1
agent-browser -p ios close
```
Requires macOS with Xcode and Appium (`npm install -g appium && appium driver install xcuitest`). Same workflow as desktop (snapshot, interact, re-snapshot). Use `--device "<UDID>"` for physical 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
Default timeout is 25s (override with `AGENT_BROWSER_DEFAULT_TIMEOUT` in ms). For slow pages, use explicit waits after `open`:
```bash
agent-browser wait --load networkidle # Best for slow pages
agent-browser wait "#content" # Wait for specific element
agent-browser wait --url "**/dashboard" # Wait for URL pattern (after redirects)
agent-browser wait --fn "document.readyState === 'complete'" # JS condition
agent-browser wait 5000 # Fixed delay (last resort)
```
## Session Management and Cleanup
Use named sessions for concurrent automations. Always close sessions when done to avoid leaked processes:
```bash
agent-browser --session agent1 open site-a.com
agent-browser --session agent2 open site-b.com
agent-browser session list # Check active sessions
agent-browser --session agent1 close # Close specific session
agent-browser close # Close default session
AGENT_BROWSER_IDLE_TIMEOUT_MS=60000 agent-browser open example.com # Auto-shutdown after inactivity
```
If a previous session was not closed properly, run `agent-browser close` to clean up the daemon.
## 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 `--stdin` with heredoc for anything beyond simple expressions (avoids shell quoting issues):
```bash
# Simple expressions
agent-browser eval 'document.title'
# Complex JS (recommended approach for nested quotes, arrow functions, multiline)
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
# Programmatic/generated scripts: base64 encoding
agent-browser eval -b "$(echo -n 'Array.from(document.querySelectorAll("a")).map(a => a.href)' | base64)"
```
## Configuration File
Create `agent-browser.json` in the project root for persistent settings. All CLI options map to camelCase keys (e.g., `--executable-path` -> `"executablePath"`). Priority: `~/.agent-browser/config.json` < `./agent-browser.json` < env vars < CLI flags.
## Deep-Dive Documentation
| Reference | When to Use |
| -------------------------------------------------------------------- | --------------------------------------------------------- |
| [references/commands.md](references/commands.md) | Full command reference with all options |
| [references/snapshot-refs.md](references/snapshot-refs.md) | Ref lifecycle, invalidation rules, troubleshooting |
| [references/session-management.md](references/session-management.md) | Parallel sessions, state persistence, concurrent scraping |
| [references/authentication.md](references/authentication.md) | Login flows, OAuth, 2FA handling, state reuse |
| [references/video-recording.md](references/video-recording.md) | Recording workflows for debugging and documentation |
| [references/profiling.md](references/profiling.md) | Chrome DevTools profiling for performance analysis |
| [references/proxy-support.md](references/proxy-support.md) | Proxy configuration, geo-testing, rotating proxies |
## Browser Engine Selection
Default engine is `chrome`. Use `--engine lightpanda` for 10x faster headless browsing (does not support `--extension`, `--profile`, `--state`, or `--allow-file-access`):
```bash
agent-browser --engine lightpanda open example.com
```