Codex Chrome extension: official option and MCP routes
The Codex Chrome extension is real, but the official Chrome listing is called ChatGPT and it connects through the desktop app. If you use Codex CLI or an IDE, you can give it browser access through an MCP server instead. Choose based on whether Codex needs your existing signed-in Chrome tabs or can work in a separate browser. OpenAI’s docs and settings were checked October 2026.
Is the Codex Chrome extension official, and what does it do?
Yes. OpenAI’s official route is the ChatGPT browser extension connected to the ChatGPT desktop app; start a ChatGPT Work or Codex chat, then choose Chrome with an @ mention. OpenAI says the desktop app can read and act on sites where you are already signed in. The setup is in Settings → Computer Use; select Chrome, install the ChatGPT extension from its store link, review its permissions, then confirm the browser shows Manage (OpenAI browser-extension docs, checked October 2026).
The store item is published by OpenAI as “ChatGPT,” not as a standalone “Codex” extension. Its listing described desktop browser control and showed 6 million users when checked in October 2026 (ChatGPT in the Chrome Web Store, checked October 2026). Browser availability can depend on rollout and workspace settings. The docs I checked do not give a plan-by-plan eligibility list, so check the app settings for your account.
OpenAI’s docs do not offer a way for the official browser extension to connect directly to a Codex CLI or IDE session. MCP is the route OpenAI documents for those clients. The desktop app, CLI, and IDE extension share their MCP configuration (OpenAI MCP docs, checked October 2026).
GitHub issue #36756 is worth reading if you expected a normal ChatGPT chat in the extension. Opened August 3, 2026, it is an open, unassigned enhancement report from one user who says the Chrome experience stayed in Work/Codex chat and offered no switch to standard chat. Treat it as a report about that user’s experience, not a guarantee about every account or a description of intended behavior (OpenAI Codex issue #36756, checked October 2026).
Which route can read signed-in tabs and take action?
The official extension and Playwright’s extension mode are the direct options for existing Chrome tabs. Chrome DevTools MCP can attach to an existing debug-enabled Chrome, but its default setup starts a separate browser. Octoweb is a separate WebKit browser with its own per-workspace data stores, so its MCP server works on Octoweb tabs, not Chrome’s.
| Route | Reads your logged-in tabs? | Can click or type? | Setup (docs-only) | Codex surface | Main boundary |
|---|---|---|---|---|---|
| Official ChatGPT extension | Yes, in the selected browser profile | Yes; can read or act on sites | Settings → Computer Use → Chrome → Install, then install ChatGPT from the store and start a Work or Codex chat with @Chrome (OpenAI docs, checked October 2026) |
ChatGPT desktop app, in a Work or Codex chat | Broad Chrome permissions may include debugger, all-site data, history, bookmarks, and downloads. Site access is managed in the app. |
| Chrome DevTools MCP | Not by default. It starts a separate Chrome profile; attach to your running profile only after enabling remote debugging | Yes; it can control and inspect Chrome | codex mcp add chrome-devtools -- npx -y chrome-devtools-mcp@latest --autoConnect (Chrome DevTools MCP README, checked October 2026) |
Codex app, CLI, and IDE through shared MCP config | Requires Chrome 144+ and remote debugging for auto-connect. The MCP client can inspect and modify data in the connected browser. |
| Playwright MCP extension mode | Yes; the extension attaches to existing tabs and reuses logged-in sessions, cookies, and installed extensions | Yes; it automates the attached browser | Install the Playwright Extension, then run codex mcp add playwright -- npx -y @playwright/mcp@latest --extension (Microsoft Playwright browser-extension docs, checked October 2026) |
Codex app, CLI, and IDE through shared MCP config | Attaches to the last-used profile with the extension unless you set --profile-dir-name. Treat its active session as sensitive. |
| Octoweb MCP | No. It controls Octoweb pages, which keep their own WebKit data stores | Yes, inside Octoweb | codex mcp add octoweb --url http://localhost:3434/mcp (OpenAI MCP docs, checked October 2026; endpoint from the product fact sheet) |
Codex app, CLI, and IDE through shared MCP config, while Octoweb is running | Mac-only WebKit browser. It has Origin checks and fences page content as untrusted, but any local process can reach a loopback port (Octoweb 0.15 notes). |
Commands in the MCP rows are docs-only: they combine the Codex CLI’s documented codex mcp add syntax with each server’s published command or URL. I did not run network installs. For details on the Codex MCP syntax, see how to add an MCP server to Codex; for the browser-automation tradeoffs, see Playwright CLI vs MCP.
What if you want the extension to work from Codex CLI?
Use MCP when your Codex session runs in the CLI or IDE. OpenAI documents one shared MCP config for the desktop app, CLI, and IDE extension, so you can add a server once and choose the browser boundary you need (OpenAI MCP docs, checked October 2026).
For a Codex Chrome MCP setup with Chrome DevTools MCP, install Node.js LTS and current Chrome first. To target a running Chrome rather than its separate default profile, start remote debugging from chrome://inspect/#remote-debugging in that browser; the MCP server requires Chrome 144+ for auto-connect (Chrome DevTools MCP configuration, checked October 2026). Playwright’s docs name the toggle on that page “Allow remote debugging for this browser instance” (Microsoft Playwright docs, checked October 2026).
To use Codex with Playwright MCP in extension mode, install the Playwright Extension in Chrome or Edge, then add the MCP command from the table. It connects to the last-used profile with that extension. To choose another, append --profile-dir-name=Profile 1 using the profile’s actual directory name (Microsoft Playwright docs, checked October 2026).
If Chrome is missing from the @ menu, open Settings → Computer Use and turn on its browser toggle. If the browser still shows Install instead of Manage, repeat the install flow. For a connection failure, update the desktop app, restart Chrome, confirm the extension is installed in the active profile, then start a new Work or Codex chat; OpenAI lists app restart and reinstall as later steps (OpenAI troubleshooting, checked October 2026).
If you only need to pass visual notes to Codex, the top Reddit result is Pinback, a third-party extension plus local MCP server. Its Chrome Web Store listing showed 27 users and Andy Biggs Ltd as developer when checked; the listing says you grant access to a site, but did not show exact permission names in the page I opened. Pinback carries comments on page elements to Codex; it is not a general tab-reading or browser-control extension, and it isn’t OpenAI’s (Pinback listing, checked October 2026).
How do you reduce risk when Codex can use your browser?
Assume an agent with browser access can encounter private page content and act in your account. Start with the smallest browser boundary that can do the task, approve sites one at a time, and review consequential actions before they happen.
OpenAI’s extension may request access to all website data, browser history, bookmarks, downloads, and the page debugger. The docs say ChatGPT asks before using a new site by default, and let you manage allowed and blocked domains in Settings → Computer Use. They also warn that page text is untrusted: misleading content could affect a task, especially if browser history is included in context (OpenAI browser-extension docs, checked October 2026).
Use a separate browser profile or an isolated browser when a task does not need your active sessions. If the task does need an authenticated tab, choose the specific site and account first; do not grant blanket access to every site just to avoid a permission prompt. Avoid sending secrets through browser tasks unless they are necessary and you are present to review each prompt.
I build Octoweb, so weigh my take on it accordingly. Its MCP route is useful if you want a Mac browser agent to work in a separate Octoweb workspace. It is macOS-only, uses WebKit, and has no browser extension support or device sync on record. Octoweb’s MCP endpoint validates Origin, labels page-authored content as <untrusted>, marks read tools with readOnlyHint, and can keep separate workspaces’ cookies apart. Those controls reduce some risks; the fact sheet also says any local process can reach a loopback port.
Which route should you choose?
Pick the route that gives Codex the narrowest browser access needed for the job:
- Pick the official ChatGPT Chrome extension if you use Codex in the desktop app and the task depends on a signed-in Chrome tab or your existing browser extensions. Review its browser permissions and keep site approvals specific.
- Pick Chrome DevTools MCP for Chrome debugging and performance work. Use its separate browser by default; attach to your regular Chrome profile only when logged-in state is required and you have deliberately enabled remote debugging.
- Pick Playwright MCP extension mode if Codex runs in the CLI or IDE and needs already-open, authenticated Chrome tabs. You are granting an MCP client access to that profile’s active session.
- Pick Octoweb MCP if you are on a Mac and want Codex to browse in Octoweb’s separate WebKit workspaces. It cannot read or control Chrome tabs.
If the task only needs the visible page’s text, pass that page or selected passage as context instead of attaching a whole browser profile. The Octoweb MCP page documents its browser boundary and setup.
Octoweb is free and open source, for macOS.
Install it →