browser-js

Lightweight CDP (Chrome DevTools Protocol) browser control for AI agents. Built as an OpenClaw skill.

3-10x fewer tokens per interaction compared to traditional browser automation tools.

Why?

Traditional browser tools for AI agents (Playwright snapshots, accessibility trees) return 2-10KB per interaction. The agent then spends thousands of thinking tokens parsing the output to find the right element to click.

browser-js returns minimal, indexed output that's immediately actionable:

[0] (link) Hacker News → https://news.ycombinator.com/news
[1] (link) new → https://news.ycombinator.com/newest
[2] (input:text) Search
[3] (button) Submit

Then bjs click 3 — done. No interpretation layer.

Install

As an OpenClaw skill

npx clawhub@latest install browser-js

Standalone

git clone https://github.com/shaihazher/browser-js.git
cd browser-js/scripts
npm install

Setup

Requires Chrome/Chromium running with CDP enabled:

# With OpenClaw (automatic):
# browser start profile=openclaw

# Or manually:
google-chrome --remote-debugging-port=18800 --user-data-dir=~/.browser-data

Optional alias

mkdir -p ~/.local/bin
echo '#!/bin/bash
exec node /path/to/scripts/browser.js "$@"' > ~/.local/bin/bjs
chmod +x ~/.local/bin/bjs

Commands

Command	Description
bjs tabs	List open tabs
bjs open <url>	Navigate to URL
bjs elements	List all interactive elements (indexed)
bjs click <n>	Click element by index
bjs type <n> <text>	Type into element
bjs upload <path>	Upload file (bypasses OS dialog)
bjs text	Extract page text (compact)
bjs eval <js>	Run JavaScript
bjs screenshot [path]	Save screenshot
bjs scroll <direction>	Scroll up/down/top/bottom
bjs url	Current URL
bjs back / forward / refresh	Navigation
bjs tab <n>	Switch tab
bjs newtab [url]	Open new tab
bjs close [n]	Close tab
bjs html <selector>	Get element HTML
bjs wait <ms>	Wait

Key Features

Auto-indexing

click and type automatically index elements if not already done. No need to call elements first.

File uploads

upload uses CDP's DOM.setFileInputFiles to inject files directly into hidden <input type="file"> elements — bypasses the OS file picker dialog entirely. Works with Instagram, Twitter, any site.

Signed-in sessions

Uses your existing browser profile with all cookies and sessions intact. If you're signed into GitHub, Instagram, LinkedIn — browser-js has access.

Token efficiency

Approach	Tokens per action	10-step flow
browser-js	~50-200	~1,500
Browser tool (snapshot)	~2,000-5,000	~30,000
Browser tool + thinking	~3,000-8,000	~60,000+

Environment

Variable	Default	Description
CDP_URL	http://127.0.0.1:18800	Chrome CDP endpoint

License

MIT