OpenAI made Codex available inside the ChatGPT mobile app for iOS and Android on May 14, 2026. The release is a preview and went to every ChatGPT plan, including the free tier. OpenAI says more than four million people now use Codex each week.

How it works

The mobile client is host-tethered, not cloud. You pair the phone to a Mac running the Codex app: update both apps, open the new Codex mobile section in the Mac app, and scan the QR code it shows. The phone then loads the live state from that Mac — the same projects, files, credentials, plugins, skills, and configuration. Codex executes on the connected host; the phone is a remote control for it, not a second copy.

What you can do from it

From the phone you can review diffs, approve or reject a command the agent wants to run, redirect a task that is already executing, watch terminal output, and get a notification when Codex finishes or needs input. You can start a new task by sending a message, pick up an active desktop session on the phone, and hand it back to the desk later.

Where it fits

The shape of the release is the notable part. Codex mobile is not a phone IDE — it is a supervision surface. The heavy work stays on the laptop and the phone becomes the place you approve it from, which makes the approval step ambient: available in a grocery line, not only at a desk. Whether moving the approval gate onto a six-inch screen is a convenience or a quiet downgrade of review is taken up in supervision from your pocket.