browser39

What it does

browser39 is a high-performance headless browser designed specifically for AI agents. It fetches modern web pages, executes JavaScript via V8, and manages encrypted session state (cookies/localStorage) locally. Its standout feature is token optimization: instead of dumping full HTML, it provides a structured list of content sections, allowing agents to fetch only the specific parts of a page they need, drastically reducing LLM context costs.

Tools

• browser39_fetch: Retrieves page content with token-optimized markdown.
• browser39_click: Interacts with elements on the page.
• browser39_dom_query: Executes custom JavaScript to extract or modify the DOM.
• browser39_fill: Fills out form fields via CSS selectors.
• browser39_submit: Submits web forms.
• browser39_search: Performs web searches via configured engines.
• browser39_config_set: Manages browser settings and auth profiles.

Installation

Install via npm:

npm install @aquintanar/browser39

Or via a one-liner for auto-configuration in AI CLIs:

curl -fsSL https://raw.githubusercontent.com/alejandroqh/marketplace/main/h39.sh | sh

Supported hosts

Confirmed support for Claude Code, Claude Desktop, Codex, OpenCode, and OpenClaw.