Codex Can Do More Than Phone Control: One Mac Can Take Over Another Mac’s Projects

Codex can do more than control a computer from the mobile app. You can also use Codex on one Mac to take over the project environment on another Mac.

More Than Phone-to-Computer Control: One Mac Can Take Over Another

Besides controlling a computer through the ChatGPT mobile app, Codex can also control another Mac directly from within Codex.

In other words, when I open Codex on my MacBook, it can read not only local files on that MacBook, but also the projects and context on another machine, such as a Mac mini.

In the past, cross-device development usually meant using tools like ToDesk, SSH, or screen sharing. They all solve the problem, but project switching, context continuity, and the overall workflow can still feel fragmented. Now, you can switch projects directly inside Codex, effectively bringing the working environment from another computer into the current Codex session.

You can see a similar effect on mobile as well: multiple devices are listed at the top.

5 Steps to Set Up Mac-to-Mac Control

Below is the complete setup process. In this example, the MacBook is the controlling device, and the Mac mini is the controlled device.

Step 0: Enable “Allow Other Devices to Connect” on the Controlled Mac

This was the first issue I ran into.

If this switch is not enabled on the controlled device, the machine may not appear when you click Add device on the controlling Mac.

On the Mac you want to control, such as the Mac mini:

1. Open Codex settings.
2. Go to “Connections”.
3. Switch to the Control this Mac tab.
4. Scroll down to Other settings.
5. Enable “Allow other devices to connect”.

This switch is off by default.

Step 1: Add the Device to Be Controlled on the Main Mac

Go back to the controlling device, such as the MacBook:

1. Open Codex settings.
2. Go to “Connections”.
3. Switch to the Control other devices tab.
4. Click Add device.

This will list other devices that are signed in under your account and have enabled the switch from the previous step. In this example, the selected device is:

Step 2: Add a Remote Project in a New Chat

Return to the main Codex interface and create a new chat.

At the bottom, click the “Select workspace” dropdown, then choose “Add remote project”.

Step 3: Select the Remote Host and Project Folder

For the remote host, select the device you added earlier, for example:

Then enter or browse to the project folder you want to take over. For example, a directory under /Users/sitin.

Step 4: Bring the Remote Project Context into Codex

After setup is complete, the remote project appears as a standalone project in the Codex sidebar.

You can also see active or existing conversation history from that Mac mini underneath the sidebar. This allows Codex on the MacBook to access the files and context of projects on the Mac mini.

In this example, the connected project on the Mac mini is hermes_ai.

When switching devices on mobile, you can also see this remote device and its projects. At this point, the project context across the two machines is connected.

What This Means for Multi-Device Developers

If you often use multiple Macs at the same time, this capability can significantly reduce the cost of switching between devices.

Previously, similar workflows usually depended on ToDesk, SSH, or screen sharing. Every time you switched, you had to confirm which machine you were on, which path you were in, and which project context was active. Now, the workflow can become: access the Mac mini’s project from the MacBook, with both files and context exposed through Codex. Instead of switching devices repeatedly, you switch projects.

Combined with the ability to control a computer from the mobile app, Codex starts to feel more like a cross-device development entry point: you may be in front of different devices, but your working environment can be connected through projects and context.

For developers who maintain multiple Macs and multiple projects at the same time, this is worth trying.