How to Install a Codex Theme on macOS

Upstream instructions can change. Before running commands, compare this guide with the original GitHub repository.

What the current upstream supports

Codex Dream Skin v1.3.3 recognizes the official desktop app as Codex.app or ChatGPT.app and states that it does not modify the app bundle, app.asar or the code signature. Its menu-bar app manages local themes through a loopback-only Chromium DevTools Protocol endpoint.

The public v1.3.3 DMG is currently unsigned. Verify the original GitHub Release and optional SHA256SUMS before using macOS's graphical Open Anyway flow. Do not disable Gatekeeper or run copied trust commands.

Requirements

macOS with the official Codex Desktop app installed.
Codex launched at least once so ~/.codex/config.toml exists.
No Node.js, Homebrew, repository clone, or shell command for the ordinary DMG path.
A trusted local session. Do not run unknown local software while CDP is active.

Install the original v1.3.3 DMG

Download CodexDreamSkin-v1.3.3.dmg and, optionally, SHA256SUMS.txt from the original GitHub Release.
Open the DMG and drag Codex Dream Skin.app to Applications.
Open it once. If macOS blocks the unsigned app, use System Settings → Privacy & Security → Open Anyway after confirming the source and checksum.
If Codex is running, quit it when prompted, then use Install / Upgrade engine from the menu-bar app.

The engine remains in ~/.codex/codex-dream-skin-studio; themes and local images remain under ~/Library/Application Support/CodexDreamSkinStudio. Update checks run only when requested and do not silently replace the app.

Apply a builder export

Download the wallpaper from this Builder, then use the menu-bar change-background action to choose that UI-free local image. The site's recipe, color tokens, and ZIP remain reviewable data; they are not executed by the DMG and are not a native one-click theme import.

Advanced source path

Only developers who deliberately chose the source installation should use the documented customizer. This is not the ordinary-user install path:

~/.codex/codex-dream-skin-studio/scripts/customize-theme-macos.sh \
  --image "/absolute/path/to/theme.webp" \
  --name "My theme" \
  --accent "#B7FF4A" \
  --secondary "#50D9F5" \
  --highlight "#8573FF"

Verify before calling it done

Open Home and confirm that the title, suggestions and project selector remain clickable.
Open a normal task and test the sidebar, composer, menus and scrolling.
Open a Diff and check that added and removed lines remain legible.
Run the upstream Verify launcher or script and record the Codex and upstream versions.

Restore

Use the menu-bar Restore or Restore and uninstall action before moving the app to Trash. Do not wait for a failure to learn rollback; read the restore guide before applying the theme.