Access Codex from another machine: Remote, SSH, or migration?

Joshua Segeren — Fri, 11 Sep 2026 01:00:46 +0000

"Use Codex from another machine" sounds like one problem. It is actually four different workflows, and choosing the wrong one can create duplicated state or a broken destination.

1. Control the current host from a phone

Use Codex Remote when Codex should keep running on the original computer and you want to supervise it from another authorized device. The host must remain awake, online, and running Codex.

OpenAI's current documentation: Remote connections and Work with Codex from anywhere.

2. Use a project that stays on another Mac

Use Remote SSH when your laptop should operate against a project and execution environment that remain on a different Mac. The remote Mac still owns the files, tools, and runtime.

This is remote access, not a copy and not synchronization.

3. Replace an old Mac with a new Mac

This is a migration. Signing into the same ChatGPT account does not turn all local Codex state and workspace files into ordinary cloud history.

A complete move may need to preserve:

local conversations and project associations;
settings, rules, memories, automations, and custom skills;
selected repositories, including .git, branches, worktrees, stashes, uncommitted files, and untracked files;
path relationships between the Codex state and those workspaces.

Avoid blindly copying all of ~/.codex. Authentication, installation identity, runtime locks, caches, and other machine-specific data should not be cloned onto the destination.

I built Codex Migrate for this Mac-to-Mac case. It inventories the selected scope, transfers directly over SSH, stages and validates the incoming data, verifies a destination rollback backup before replacement, and preserves the new Mac's existing Codex login and installation identity.

The CLI and source are MIT licensed. The signed and Apple-notarized Apple-silicon beta is $50 once, with best-effort support and a 30-day refund policy.

4. Work actively on both computers

That is synchronization, not migration. It requires conflict handling for Git state, uncommitted files, sessions, paths, and machine-local configuration. Repeatedly mirroring all of ~/.codex is not a safe substitute.

Quick decision table

What you want	Use
Check the running host from your phone	Codex Remote
Keep the project on another computer	Remote SSH
Retire the old Mac and continue on the new one	One-time migration
Work on the same state from two active computers	A real synchronization system

I wrote a longer, source-linked comparison here: Access Codex from another machine.

Disclosure: I maintain Codex Migrate. It is an independent project and is not affiliated with or endorsed by OpenAI.

How to Move OpenAI Codex to a New Mac Without Cloning Its Identity

Joshua Segeren — Fri, 11 Sep 2026 00:02:59 +0000

Changing Macs is normally straightforward. The surprising part is that signing into the same ChatGPT account does not necessarily recreate the local Codex working environment you had on the old machine.

Your repositories are only part of that environment. Local Codex conversations and state, project organization, custom skills, settings, Git worktrees, stashes, branches, and unfinished files can still live on the old Mac.

Here is the safe mental model and checklist I wish I had before my own move.

First: decide whether you need migration or sync

A migration is a one-time move from an old Mac to a new Mac. The old environment is the source; the new installation is the destination.

Sync means two Macs keep changing and must reconcile those changes repeatedly. That is a different and much harder problem. Blindly syncing internal Codex databases between two active installations can create conflicts or duplicate machine identity.

This guide covers migration.

What usually needs to move

For a complete developer-workspace move, inspect these categories separately:

Portable local Codex conversations and working state
User configuration, rules, memories, automations, and custom skills
Selected project folders
Complete Git metadata: .git, local branches, worktrees, stashes, uncommitted files, and untracked files
Any workspace paths referenced by local Codex state

A Git push is valuable, but it does not automatically include uncommitted work, stashes that were never pushed, linked worktrees, local-only branches, or Codex’s local state.

What you should not clone blindly

Do not treat the entire ~/.codex directory as one portable blob.

The destination Mac should keep its own:

Codex/ChatGPT authentication
Installation or device identity
SSH private keys
Runtime sockets and locks
Logs and disposable caches

Copying machine-specific identity can make two physical Macs appear to Codex Remote Control as the same installation. Copying credentials also creates avoidable security risk.

Install ChatGPT/Codex on the new Mac, open it, and sign in once before replacing any portable state. That gives the destination its own authentication and installation identity to preserve.

A safer transfer sequence

Keep the old Mac intact. Do not erase, trade in, or repurpose it yet.
Make an independent backup. A rollback copy on the destination disk does not protect against disk failure.
Inventory before copying. Find external Git directories, linked worktrees, cloud-only placeholders, symbolic links, permissions issues, and required disk space.
Connect the Macs securely. SSH works over ordinary Wi-Fi, a USB-C network connection, or Thunderbolt. Verify the destination host fingerprint; do not disable host-key checking.
Stage first. Copy into a separate staging area rather than directly over the live destination.
Back up the destination. Verify that backup before replacing selected data.
Close Codex writers on both migration accounts. Databases and state files should not be changing during finalization.
Install, then verify. Check restored conversations, Codex identity, Git status, worktrees, branches, stashes, and representative projects.
Plan for interruption. A cable disconnect, Wi-Fi loss, sleep, crash, or full disk should leave a resumable staged copy—not a half-replaced live workspace.

Verification matters more than “copy completed”

After the move, check at least:

The new Mac is still signed into the intended ChatGPT account
Its Codex installation identity is distinct from the old Mac
Expected active and archived conversations appear
Selected projects open at the intended paths
git status matches the source for representative repositories
Local branches, stashes, and linked worktrees are present
Uncommitted and untracked files exist
A real build or test runs on the new Mac

Only then should you consider the migration complete.

The guided option I built

I ran into this problem myself, so I built Codex Migrate for this specific one-time Mac-to-Mac workflow.

It transfers portable Codex state and selected workspaces directly between your Macs over SSH. It inventories dependencies, stages the transfer, preserves the destination Mac’s authentication and installation identity, requires a verified destination backup before replacement, and supports pause/resume and recovery after interruption.

Free MIT-licensed CLI and source
Signed and Apple-notarized Apple-silicon beta — $50 once, with direct best-effort support and a 30-day refund policy

The paid app and free CLI use the same migration engine and safety checks. Payment covers the packaged, signed workflow and maintainer support—not stronger data protection.

Codex Migrate is an independent project. It is not affiliated with, supported by, or endorsed by OpenAI. Keep your old Mac and an independent backup until you have verified the result.

DEV Community: Joshua Segeren