Codex on a Mac mini: an always-on host you control from your phone

Why a Mac mini as the Codex host

Your phone doesn't run Codex. It sends prompts, approvals and follow-ups, and the host supplies everything else: projects, chats, files, credentials, plugins, MCP servers, skills, Computer Use, the browser and local tools. So the host decides what Codex can do from your phone, and whether it's reachable at all. A Mac mini that never sleeps makes a good one:

• It stays on. A host that sleeps, loses its network or closes the app cuts remote access until it's back.
• Computer Use and browser tasks. The ChatGPT desktop app runs Computer Use on macOS and Windows; the Linux preview doesn't have it yet. On Windows, Computer Use takes over the active desktop and needs the session unlocked. A Mac has locked use, so a Computer Use task you start from your phone can run after the Mac locks.
• iOS apps. Xcode and the iOS Simulator run only on macOS, so if Codex works on an iPhone app, the host has to be a Mac.
• Your data at home. Repositories, browser sign-ins and credentials stay on a machine you own, and signed-in websites and desktop apps work because the host can reach them.
• A base for servers too. The same desktop app can add Linux servers as SSH hosts, so the Mac mini can be the always-on computer your phone connects to while chats run on a server.

What you need

• A Mac mini you can leave switched on and connected to the internet.
• A ChatGPT account with Codex access. OpenAI's plan table lists mobile remote control on Plus, Pro, Business and Enterprise; it isn't available with an API key. In a ChatGPT workspace, an admin may need to turn on Remote Control access first.
• The latest ChatGPT app on your phone, iOS or Android, signed in to the same account and workspace as the Mac mini.
• Optionally, Tailscale on the Mac mini and your laptop, to reach the Mac mini's desktop from anywhere.

How to set up Codex on a Mac mini

1. Install the ChatGPT desktop app and the Codex CLI

   Since July 9, 2026, Codex lives in the ChatGPT desktop app, next to Chat and Work. Install the app for macOS, sign in with the account and workspace you use on your phone, and select Codex. The Codex CLI is optional but handy when you SSH in: install it with OpenAI's script or Homebrew, run codex and choose Sign in with ChatGPT. codex app opens the desktop app, and installs it if it's missing.

   # Codex CLI on macOS (either one; the script also updates it)
   curl -fsSL https://chatgpt.com/codex/install.sh | sh
   brew install --cask codex
   
   # Open the ChatGPT desktop app, installing it if it's missing
   codex app
   
   # Sign in to the CLI with your ChatGPT account
   codex login

2. Keep the Mac mini awake

   In System Settings > Energy, turn on Prevent automatic sleeping when the display is off, so the Mac mini keeps running with its display off; Wake for network access lets it wake for shared services (see Apple's sleep and wake settings). Then, in the desktop app, turn on Settings > General > Prevent sleep while running, so local chats keep going while you're away.

3. Turn on remote control

   In the desktop app, open Settings > Connections > Control this Mac or PC and select Set up or Add. Approve remote access and finish any verification; the app shows a QR code. Settings > Connections is also where you choose to keep the computer awake, enable Computer Use, install the Chrome extension and manage connected devices.

4. Pair your phone

   Scan the QR code with your phone; it opens ChatGPT. Confirm the account and workspace and complete any MFA, SSO or passkey step. The Mac mini then shows up under Codex in the ChatGPT app (Remote in older versions), and you can start chats in its projects, approve commands and review diffs. A QR code pairs one phone with one host, so pair each phone you'll use. To control it from a laptop too, use Settings > Connections > Control other devices on the laptop, where that option is available.

5. Turn on Computer Use and the Chrome extension

   For browser and desktop tasks the host needs both. With Codex selected, open Settings > Computer use, find Any App under Control and select Install or turn the switch on, and install the Chrome extension from Settings > Connections. Computer Use is available only in some regions. To let a Computer Use task you start from your phone run while the Mac is locked, turn on locked use in Settings > Computer Use. It installs an Apple authorization plug-in, unlocks only for an active Computer Use turn, and locks again if someone uses the Mac mini's keyboard or pointer.

6. Add SSH hosts if your code lives on a server

   Settings > Connections can also add a Linux server from ~/.ssh/config as an SSH host; you then choose a project folder on it. Chats in that project run on the server, while your phone keeps connecting to the Mac mini. The setup is in Codex on a VPS.

7. Reach the Mac mini's desktop with Tailscale and Screen Sharing

   Install Tailscale on the Mac mini and your laptop and add both to the same tailnet, a private network where only your devices can reach each other over encrypted WireGuard connections (see what Tailscale is). On the Mac mini, turn on System Settings > General > Sharing > Screen Sharing; it can't be on at the same time as Remote Management. Then connect from your laptop to the Mac mini's name on your tailnet to sign in to websites, answer security or privacy prompts that Computer Use can't approve, or watch Codex work (see Apple's Screen Sharing guide).

Source: OpenAI's docs on remote connections

What keeps it reachable, and what stops it

• The Mac mini has to stay awake, online and signed in to the same account and workspace, with the desktop app open. If it sleeps, loses its network or the app closes, your phone can't reach it until it's back. Choosing Sleep yourself stops access too.
• Signing out of the desktop app turns Remote Control off but keeps your pairings. After you sign back in, turn Remote Control on again.
• If an error appears after you select Add, restart the desktop app on the Mac mini and try again. Pairings not used since June 8, 2026 need both apps updated and pairing again.
• Remote control doesn't start work by itself. When a task is done, Codex notifies you and waits for your next prompt. For scheduled tasks and other ways to start work without you, see proactive Codex and Codex long-running tasks.
• More fixes are in Codex remote control.

Other ways to keep Codex reachable

• A Linux server as an SSH host runs Codex on the server, but your phone still connects to a Mac or Windows PC running the desktop app, so that computer has to stay on as well. The Mac mini can be it. See Codex on a VPS.
• Codex cloud runs tasks on OpenAI's cloud and keeps working while your computer sleeps. It only sees its cloud environment, so your local files, browser sign-ins and VPN access aren't there.
• For Claude Code, the same always-on Mac mini setup is in Claude Code on a Mac mini, and Anthropic's version of remote control in Claude Code Remote Control.

Give the always-on Mac mini a standing job

An always-on Mac mini answers whenever you message it from your phone, and waits when you don't. Crewmark turns a Codex chat on it into an AI employee with a role, a goal in numbers, working hours and a heartbeat: during working hours the crewmark CLI wakes the employee to work through its issues on a shared board. The computer it runs on has to stay on, and the Mac mini does.

1. Hire an employee

   Pick a role from the AI employee roles, such as software engineer or SEO specialist, and write its goals and KPIs.

2. Connect Codex on the Mac mini

   Paste the setup link into a Codex chat on the Mac mini. It installs the crewmark CLI and links that chat to the employee. Claude Code works too.

3. Set working hours and a heartbeat

   Choose the hours, weekdays only or every day, and how often the employee wakes: every 15, 30, 60, 120 or 240 minutes. Hours can run past midnight, so on a machine that never sleeps a night shift works too. Each wake-up goes into the same Codex chat, so it carries on where it left off.

4. Assign issues and talk to it from your phone

   Open crewmark.ai in your phone's browser to create and assign issues, or write to the employee in its Work log; it answers there. Assigning an issue wakes it right away, and when it needs a review or a decision it sets the issue to Needs action and asks you there. Jobs to give it are in Codex use cases.

FAQ