# Give Codex a browser on a Mac

To give Codex a browser on a Mac, install Serein. Serein is a free macOS browser that finds the Codex command-line tool on the Mac and runs it with your own Codex sign-in. Web tasks then run in visible browser tabs that you can watch, take over or stop.

## What you need

- A Mac with macOS 14 or later.
- The Codex command-line tool. If it is not installed, Serein's setup can run Codex's own install command for you, in a terminal inside Serein.
- No API key. Serein uses the sign-in of the Codex tool and never asks for your password.

## Steps

1. Download Serein from https://serein.pro/#download, open the disk image and move Serein to the Applications folder.
2. Open Serein. The setup lists each agent tool that it finds. Codex shows one action: Install, Sign in, Update or Ready. The action runs Codex's own command.
3. Press `⌘E` to open the composer and write the task. Choose Codex and a model in the model picker.
4. The task opens visible agent tabs. These tabs have their own cookies, not yours. A pointer moves to each element before the agent acts on it.
5. Give more access only when the task needs it: clicks and typing, your sign-ins for this task, or edits in a project. All of these are off at the start.
6. Use Take Over to make an agent tab yours, or Stop to end the task. Stop takes the task's browser access away at once.

## More ways to use it

- **Ask about the page in view.** `⌥⌘E` opens the task panel beside the page, with the page and your selection attached. You see exactly what is sent.
- **Point at elements.** `⇧⌘E` lets you point at up to three elements of a page.
- **Work in a project.** Serein finds your repositories from Codex history. Start a task in a project, read the diff of each turn, and undo or redo it. Each edit needs your approval.
- **Continue a conversation.** A follow-up resumes the native Codex session, so the context is kept.

## What Serein enforces on a Codex task

- Codex reaches the browser only through tools that Serein gives to that task.
- Your own MCP servers, plugins and hooks are kept out of the task.
- The task cannot change files unless you grant edits.
- On a password, payment or verification-code page, the task gives the tab back to you.
- Private windows are never shared with the agent.

Four access levels map to Codex's own flags: Supervised (the default), Auto-accept edits, Auto and Full access. Full access needs edits granted and a confirmation the first time in each project.

## Limits

- Serein is for macOS only.
- Up to three tasks run at the same time.
- Agent tabs cannot download files.
- Codex sends the task and its context to its provider (OpenAI, unless you set another) under your account. Serein does not run a model on the Mac.

More: https://serein.pro/llms/permissions.md, https://serein.pro/llms/faq.md, https://serein.pro/llms.txt