Codex Native Selector

A local customization of the Codex Desktop model selector, built from the Codex installation already present on Windows.

This project turns Codex's compact model selector into a clearer and faster interface: model variants in tabs, the native reasoning slider, model-specific animated colors, Fast mode, a settings button, and an automatically grouped model menu.

The project does not redistribute Codex or replace the official installation. It generates a local portable copy from the Codex installation already on your computer.

Preview

┌──────────────────────────────────────────────┐
│  Sol       Terra       Luna       ⚡    ⚙     │
│                                              │
│  ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━●            │
└──────────────────────────────────────────────┘
              5.6 Terra  Very high

The ⚙ button opens the available model families, such as 5.6, 5.5, 5.4, and 5.3 Codex Spark. Variants remain in the top row, so the model menu does not duplicate Sol, Terra, Luna, or Mini.

Features

• Uses Codex Desktop's native model-power slider component.
• Reads reasoning efforts from the real Codex model catalog.
• Shows model variants only when they actually exist.
• Displays a fixed Full tab for a family with no selectable variant.
• Groups the model menu automatically by model family.
• Recolors the Ultra animation using the active model family's color while preserving the native slider animation.
• Keeps Fast mode in the same row as the model variants.
• Renders the model menu above the interface through a DOM portal to avoid clipping and z-index issues.
• Creates a separate portable copy while leaving the official Microsoft Store installation untouched.

How it works

flowchart LR
    A[Official Codex installation] --> B[Local app.asar]
    B --> C[Temporary extraction]
    C --> D[Targeted bundle patch]
    D --> E[Portable app.asar]
    E --> F[Customized native selector]
    F --> G[Real Codex catalog and efforts]

Loading

The patch only targets the selector bundle and preserves the original application structure, components, events, and backend. The rest of the application is copied without modification.

Installation

Requirements

• Windows 10 or Windows 11.
• Codex Desktop installed officially, preferably through the Microsoft Store.
• Node.js 22.12 or newer.
• PowerShell.
• Codex fully closed while building and launching.

1. Clone the repository

git clone https://github.com/Mirochill/codex-native-selector.git
Set-Location .\codex-native-selector
npm install

2. Find the installed Codex directory

The directory usually looks like this:

C:\Program Files\WindowsApps\OpenAI.Codex_<version>_x64__2p2nqsd0c76g0\app

To automatically find the most recent version:

$package = Get-ChildItem 'C:\Program Files\WindowsApps' -Directory -Filter 'OpenAI.Codex_*' |
  Sort-Object LastWriteTime |
  Select-Object -Last 1
$installApp = Join-Path $package.FullName 'app'
$installApp

If Windows denies access to WindowsApps, use the installation path shown in Codex's properties or enter the path manually.

3. Extract the official archive temporarily

This reads the local application but does not modify the official installation:

Remove-Item .\work\asar-extracted -Recurse -Force -ErrorAction SilentlyContinue
npx --yes @electron/asar extract `
  (Join-Path $installApp 'resources\app.asar') `
  .\work\asar-extracted

4. Build the customized copy

powershell.exe -NoProfile -ExecutionPolicy Bypass `
  -File .\tools\build-portable.ps1 `
  -InstallApp $installApp

The result is generated in:

outputs\Codex-Native-Selector\

5. Launch Codex Native Selector

Close official Codex, including its tray icon in the Windows notification area, then launch:

outputs\Codex-Native-Selector\Launch Codex Native Selector.cmd

The official and customized copies must not run at the same time because they use the same local Codex environment.

Updating after a Codex update

The Codex frontend bundle can change its filenames or structure after an update. Rebuild from the new installation:

Remove-Item .\work\asar-extracted -Recurse -Force -ErrorAction SilentlyContinue
npx --yes @electron/asar extract `
  (Join-Path $installApp 'resources\app.asar') `
  .\work\asar-extracted
powershell.exe -NoProfile -ExecutionPolicy Bypass `
  -File .\tools\build-portable.ps1 `
  -InstallApp $installApp

If the script reports that a chunk or function cannot be found, the Codex version has probably changed. Update the search markers in tools/build-inplace-asar.mjs and rebuild.

Advantages

Area	Benefit
No Codex fork	The project does not maintain a complete copy of the application.
No reinstallation	The copy is rebuilt from Codex already installed locally.
Official installation preserved	The Microsoft Store package is not overwritten.
Native components	The slider, its events, and model behavior remain Codex components.
Dynamic catalog	Models and reasoning efforts come from Codex's real configuration.
Targeted maintenance	The patch focuses on one frontend bundle.

Important limitations

• This is not an official plugin: Codex Desktop does not expose a public API for replacing its native UI with a plugin.
• The project currently targets Windows.
• The copy is tied to the Codex version and frontend chunk names used during the build.
• A Codex update may require changes to the patch.
• The official archive is not included on GitHub because of its size, redistribution concerns, and software ownership.
• The project does not bypass authentication, account limits, or service rules.
• The official instance must be closed before launching the customized copy.
• Available models still depend on the user's account, plan, and Codex backend.

Troubleshooting

The application stays on the OpenAI logo

Make sure that app.asar was extracted from the currently installed Codex version, then rebuild the copy. An old extracted archive may contain incompatible chunk names.

The launcher says that another instance is open

Quit Codex from the Windows notification-area icon. Closing only the main window may leave the background process running.

The selector does not show new models

Rebuild from the newest official archive. This project does not manufacture a model list: it reuses the catalog exposed by Codex.

I want to return to official Codex

Close the customized copy, then launch Codex from the Start menu. No uninstall or file restoration is required.

Repository structure

tools/
├── build-portable.ps1       # Copies the local installation and creates the launcher
├── build-inplace-asar.mjs   # Applies the targeted app.asar patch
└── selector-v2.js.txt        # Customized selector component

README.md
LICENSE
.gitignore
package.json

The outputs/, work/asar-extracted/, and generated archives are ignored by Git so that a full Codex copy, local profile, or personal data cannot be published accidentally.

License

The scripts and customization code in this repository are distributed under the MIT License.

Codex Desktop, its components, resources, and models remain the property of their respective owners. This community project is not affiliated with or endorsed by OpenAI.