GptSkin builds image-backed themes for the Codex desktop app. Attach your own image, or ask Codex imagegen to create one locally first. The open-source Skill sends that image through the same paid build pipeline and applies the result to your running Codex interface.
How It Works
GptSkin works through an open-source Codex Skill. Once installed, the Skill applies themes by injecting CSS variables, backgrounds, and controlled decorative layers into the running official Codex interface via a Chrome DevTools Protocol (CDP) launch flag that binds only to the loopback address (127.0.0.1).
Just as important is what GptSkin does not do:
- It never modifies the official app installation package,
app.asar, or code signatures. - It never touches your API Key or Base URL.
- It never reads your Codex conversations, and never sends your Codex DOM or session data to the cloud.
Want the stock look back? Say Restore the default Codex theme and every injection is removed, with Codex restarting normally.
Free Presets and Custom Themes
Six preset themes are free for everyone — no account required: dark-void, sunset-glow, aurora-borealis, snow-peak, city-lights, and minimal-light. Try one with a single command:
node ~/.codex/skills/gptskin-theme/scripts/apply-theme.mjs --preset dark-voidEvery paid custom theme starts with an image (max 4 MiB, JPEG/PNG/WebP). Attach your own, or have Codex imagegen create a local image first; the Skill sends either file through the same --image flow. Your uploads and completed themes are never used to train models.
The website manages your account, Credits, API Key, theme history, and artifacts. The Skill performs the paid build and applies the finished theme locally in Codex.
Safety and Transparency
GptSkin is built for trust by design:
- Loopback-only CDP: the debug port is never exposed to the network. The Skill disconnects after injection, but the port remains available while the Codex process launched with the debugging flag is alive. A loopback port has no application-layer authentication — see our security docs for the full picture.
- Verified theme packages: delivered themes pass a hash check before application.
- Open source: the Skill is fully auditable at github.com/WendongAI/gptskin-skill.
- Reversible: everything can be removed with one command.
GptSkin is an independent product and is not affiliated with, endorsed by, or officially connected to OpenAI. "ChatGPT" and "Codex" are trademarks of OpenAI, used only to describe compatibility.
Pricing
GptSkin uses one-time Credit packages — not a subscription:
| Package | Price | Credits |
|---|---|---|
| Builder | $9.9 | 100 |
| Pro | $19.9 | 500 |
| Studio | $49 | 1500 |
Paid Credits never expire. New accounts receive bonus Credits (valid for 30 days), and each new image-backed theme costs 20 Credits. Reapplying a saved theme is free. Payments are processed by Creem as Merchant of Record, which also handles applicable taxes — GptSkin never sees your card details.
Get Started
GptSkin supports the Codex desktop app on macOS and Windows with Node.js 20+. Head to the installation guide to set up the Skill in minutes, or start with a free preset — no sign-up needed.
