Agent Browser

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

Works with: Claude Code, Cursor, GitHub Copilot, OpenAI Codex, Google Gemini, opencode.

Quick Navigation

When to Use

• Automating browser tasks in AI agent workflows
• Web scraping with AI-friendly output
• Testing web applications with LLM agents
• Managing multiple browser sessions with isolated auth

Core Concepts

Refs (Element References)

The snapshot command returns an accessibility tree where each element has a unique ref like @e1, @e2:

• Deterministic – ref points to exact element from snapshot
• Fast – no DOM re-query needed
• AI-friendly – LLMs can reliably parse and use refs

Architecture

Client-daemon architecture:

1. Rust CLI – parses commands, communicates with daemon
2. Node.js Daemon – manages Playwright browser instance

Daemon starts automatically and persists between commands.

Quick Example

# Navigate and get snapshot
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 "test@example.com" # Fill input by ref
agent-browser get text @e1                # Get text by ref
agent-browser screenshot page.png         # Save screenshot
agent-browser close

AI Workflow Pattern

Optimal workflow for AI agents:

# 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 (Debugging)

agent-browser open example.com --headed

JSON Output

Use --json for machine-readable output:

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

Critical Prohibitions

• Do not use CSS/XPath selectors when refs are available (use @e1, @e2, etc.)
• Do not forget to close sessions when done
• Do not assume element positions without taking a fresh snapshot
• Do not use old refs after page navigation or content changes (re-snapshot)

Common Commands

# Navigation
agent-browser open <url>
agent-browser back / forward / reload
agent-browser close

# Interaction
agent-browser click <sel>
agent-browser fill <sel> <text>
agent-browser press <key>
agent-browser hover <sel>
agent-browser select <sel> <val>
agent-browser download <sel> <path>  # v0.7+

# Info
agent-browser get text <sel>
agent-browser get url
agent-browser get title
agent-browser is visible <sel>

# Snapshots & Screenshots
agent-browser snapshot -i --json
agent-browser screenshot [path]

Links

• Official docs: https://agent-browser.dev/
• Changelog: https://agent-browser.dev/changelog
• GitHub: https://github.com/vercel-labs/agent-browser