Installation

System Requirements

• macOS or Windows
• Codex desktop app
• Node.js 20+ (verify with node -v)

Paid custom theme builds additionally require a free account at gptskin.best. The 6 preset themes work without any account.

1. Install the Skill

The GptSkin Skill is open source (GitHub). Install it into your Codex skills directory:

git clone https://github.com/WendongAI/gptskin-skill.git ~/.codex/skills/gptskin-theme
cd ~/.codex/skills/gptskin-theme
npm install

Restart Codex so it picks up the new Skill. You can verify the scripts are in place:

node ~/.codex/skills/gptskin-theme/scripts/apply-theme.mjs --help

2. Try a Free Preset

No account needed. In Codex, just say:

Apply the dark-void preset theme

Or run the script directly:

node ~/.codex/skills/gptskin-theme/scripts/apply-theme.mjs --preset dark-void

Available presets: dark-void, sunset-glow, aurora-borealis, snow-peak, city-lights, minimal-light.

3. Custom Themes (API Key)

GptSkin has one paid custom-theme type: an image-backed theme. The website manages your account, Credits, API Key, and theme artifacts; the open-source Skill performs the paid build and applies the result locally in Codex.

1. Register at gptskin.best — you'll receive bonus Credits (valid for 30 days).
2. Copy your API Key from the dashboard.
3. Configure it for the Skill:

node ~/.codex/skills/gptskin-theme/scripts/apply-theme.mjs --key YOUR_API_KEY

Now attach an image (max 4 MiB, JPEG/PNG/WebP), or ask Codex imagegen to create a local image first. The Skill passes either image into the same paid command:

node ~/.codex/skills/gptskin-theme/scripts/apply-theme.mjs --image /absolute/path/theme.png "Theme Name"

Each new custom image theme costs exactly 20 Credits. Reapplying a locally saved theme is free. The Skill should ask before spending Credits and before restarting Codex with local CDP enabled.

Restore the Default Theme

At any time, tell Codex:

Restore the default Codex theme

This removes all injected styles and decorative layers and restarts Codex normally.

Troubleshooting

• Theme doesn't apply after a desktop app update — app updates can change internal interface structures. Restore the default theme first, then pull the latest Skill (git -C ~/.codex/skills/gptskin-theme pull) and try again.
• node: command not found — install Node.js 20+ and make sure it's on your PATH.
• "Invalid API Key" — re-check the key in your gptskin.best dashboard and run --key again.
• Image rejected — uploads must be JPEG, PNG, or WebP and at most 4 MiB.
• Nothing changed visually — make sure Codex was restarted after installing the Skill, and that the theme application reported success.

Need more help? Email support@gptskin.best — we respond within 3 business days.