chrome-agent 0.2.1

CLI tool for AI agents to observe and interact with Chrome via CDP

chrome-agent

A CLI tool that gives AI coding agents the ability to observe and interact with Chrome browsers.

Built as a replacement for browser MCP tools. Faster, lower token overhead, and supports something MCP tools can't do: multiple agents sharing the same browser instance.

Why this exists

AI coding agents need to see and interact with browsers -- to test their code, debug automation, inspect page state. The standard approach (browser MCP tools) uses a persistent server with protocol negotiation and verbose response formatting. chrome-agent takes a different approach: each command is a standalone CLI call that connects to Chrome via the DevTools Protocol, does one thing, and disconnects. No server, no session state, no bloat.

This also enables a workflow that MCP tools can't support: one process drives the browser (your automation code) while a separate agent observes the same browser to diagnose issues and improve the code.

Installation

uv tool install chrome-agent
playwright install chromium

Or add to a project:

uv add chrome-agent
uv run playwright install chromium

Two ways to use it

Drive mode -- you control the browser

Launch a browser and interact with it directly. This is the MCP replacement use case.

chrome-agent launch &
chrome-agent navigate "https://example.com"
chrome-agent text                        # Read page content
chrome-agent element "h1"                # Inspect an element
chrome-agent fill "#search" "query"      # Fill a form field
chrome-agent click "#submit"             # Click a button
chrome-agent screenshot /tmp/page.png    # Capture the screen

Attach mode -- observe a running browser

Your automation code launches a browser with --remote-debugging-port=9222. You connect to observe what the code is doing, diagnose failures, and figure out what to change.

chrome-agent status                      # Is the browser running?
chrome-agent url                         # Where is it?
chrome-agent element "#submit-btn"       # Why can't the code click this?
chrome-agent eval "document.querySelectorAll('.error').length"
chrome-agent screenshot                  # What does it look like?

The feedback loop: write code -> run it -> observe the browser -> diagnose -> modify code -> repeat.

Commands

chrome-agent [--port PORT] <command> [args...]

Check browser status

status                Check if a browser is running on the CDP port
launch                Launch a browser with CDP enabled
                      [--fingerprint PATH] [--headless] [--no-pin-desktop]
help                  Print command reference

Observe (read-only, always safe)

url                   Print current URL and page title
screenshot [path]     Save a screenshot (default: /tmp/cdp-screenshot.png)
snapshot              Print the ARIA accessibility tree
text                  Print visible text content
html [selector]       Print page HTML or a specific element's HTML
element <selector>    Detailed element inspection (visibility, dimensions,
                      attributes, position, disabled state)
find <selector>       Count and list all matching elements
value <selector>      Get an input element's current value
eval <code>           Execute JavaScript and print the result
cookies               List all cookies
tabs                  List all open tabs/pages
wait <target>         Wait for a selector, milliseconds, or load state

Navigate

navigate <url>        Go to a URL
back                  Browser back
forward               Browser forward
reload                Reload the page

Interact

click <selector>      Click an element (JS fallback for hidden elements)
fill <selector> <val> Fill a form field (clears first)
type <selector> <txt> Type text character by character
press <key>           Press a keyboard key (Enter, Escape, Tab, etc.)
select <sel> <value>  Select a dropdown option
check <selector>      Check a checkbox
uncheck <selector>    Uncheck a checkbox
hover <selector>      Hover over an element
scroll <target>       Scroll to element, or scroll up/down
clickxy <x> <y>       Click at page coordinates
close                 Close the current page
viewport <w> <h>      Resize the viewport

For AI agents

The primary user of this tool is an AI coding agent, not a human. See INSTRUCTIONS.md for comprehensive agent instructions covering:

• Drive mode vs attach mode mental model
• Safety rules for shared browser access
• The development feedback loop
• When to observe vs intervene
• Command recipes for common tasks
• Failure modes and recovery

Include the contents of INSTRUCTIONS.md in your project's CLAUDE.md or agent instructions file.

Browser fingerprinting (optional)

For sites that detect automated browsers, launch with a fingerprint profile:

chrome-agent launch --fingerprint path/to/fingerprint.json

The fingerprint JSON overrides the browser's user agent, viewport, locale, timezone, and platform to match a real desktop browser:

{
    "userAgent": "Mozilla/5.0 (X11; Linux x86_64) ...",
    "platform": "Linux x86_64",
    "vendor": "Google Inc.",
    "language": "en-US",
    "timezone": "America/Chicago",
    "viewport": {"width": 1920, "height": 1080}
}

Without --fingerprint, the browser launches with default Chromium settings.

Requirements

• Python >= 3.11
• Playwright >= 1.50.0
• Chromium (installed via playwright install chromium)
• Linux with xdotool (optional, for virtual desktop pinning)

License

MIT