Overview

This guide explains how to use and troubleshoot the Codex Chrome Extension on Windows, especially when it works on the first day but stops working after restarting Codex, Chrome, or after a Codex app update.

It is based on a real debugging session where the Chrome extension showed Connected, but Codex could not reliably control Chrome until the startup order and plugin state were cleaned up.

Symptoms

You may see one or more of these symptoms:

• The Codex Chrome Extension popup says Connected, but Codex cannot control Chrome.
• Typing @ in Codex does not show Chrome.
• Settings -> Computer use shows Computer Use plugins unavailable.
• Settings -> Browser shows In-app browser plugin unavailable.
• @Chrome works once, but disappears after restarting Codex or Chrome.
• Chrome stays open from yesterday, Codex updates or restarts, and the old controlled tab is still open but no longer controllable.
• Codex configuration still has chrome@openai-bundled enabled, but the current conversation does not expose the Chrome control tools.

Mental Model

There are several layers involved. The Chrome extension popup being Connected only proves one layer is alive.

Think of the integration as four layers:

1. Codex App loads the bundled Chrome and Browser plugins.
2. The current Codex conversation receives the browser-control tools.
3. The Codex Chrome Extension is installed and enabled in the correct Chrome profile.
4. The Chrome native messaging host is registered and reachable.

If any layer is broken, @Chrome may fail even if the Chrome extension says Connected.