Name the delivery layer
Document whether a choice is native, a pack token, or an unofficial local background so users know where to adjust it.
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Codex theme setup decisions
Codex theme setup, without the guesswork.
The visual idea is only half the job. A dependable theme pack must account for the operating system, window ratio, display arrangement, native settings, unofficial background behavior, and a clean way back to stock Codex.
How to use this library
Choose with the finished workspace in mind.
These pages separate configuration that Codex exposes from behavior supplied by the reversible local runtime. That distinction matters for troubleshooting, support, and honest expectations about what will appear inside the app's settings.
Platform guidance also treats cropping as a delivery problem. A background must survive wide displays, compact windows, and focus changes without hiding the subject under navigation or reducing text contrast.
Browse every guide
9 specific starting points, each with its own tradeoffs.
01 · macOS
Codex themes on macOS, with a clear way back.
A macOS theme pack should feel native to operate even when its advanced background is not a native Codex setting. That means readable scripts, local-only files, explicit prerequisites, and a restoration path that does not modify the signed application bundle.
Open guide →02 · WindowsCodex themes for Windows desktop setups.
Windows setups vary from a single 16:9 laptop to multi-monitor workstations with different scaling levels. A useful pack makes those differences explicit and supplies Windows-specific commands instead of treating a macOS shell script as universal documentation.
Open guide →03 · DesktopDesign a Codex desktop theme for real window shapes.
A desktop theme is not a wallpaper pasted under an interface. Navigation, task surfaces, dialogs, side-by-side windows, and display changes cover different parts of the composition, so the pack needs several intentional assets and a stable contrast strategy.
Open guide →04 · Background imageCreate a Codex background image that fits the interface.
The best Codex background is designed around what will cover it. It offers a calm field under navigation and task surfaces, places the meaningful subject toward a safe outer region, and includes enough visual context to survive three desktop ratios.
Open guide →05 · Appearance settingsKnow what belongs in Codex Appearance settings.
Theme language can hide an important distinction. Native choices that Codex exposes in Appearance are different from a downloadable pack's visual tokens, and both are different from an advanced background supplied by an unofficial local compatibility layer.
Open guide →06 · WidescreenA widescreen Codex theme that uses the extra room.
Wide displays create space for atmosphere, but they also tempt theme authors to place important content at both extremes. The Codex window may not remain full screen, so a durable composition feels complete at full width and still works when only its central or compact crop is visible.
Open guide →07 · Multi-monitorKeep a Codex theme consistent across multiple displays.
Two displays rarely reproduce a theme identically. They may differ in ratio, density, scaling, black level, color, and room position, so multi-monitor quality comes from resilient contrast and alternate crops rather than one perfectly tuned screenshot.
Open guide →08 · Low distractionReduce visual distraction without losing useful hierarchy.
Low distraction is not the absence of color. It is a controlled attention model in which the current task, focus state, and important status are clear while background atmosphere, inactive controls, and decorative borders remain subordinate.
Open guide →09 · Reversible themesChoose a Codex theme with restoration built in.
Customization is easier to trust when the return path is designed at the same time as activation. A reversible pack keeps its files separate from the signed application, exposes what is active, and offers a clear command to stop the optional layer and return to native Codex.
Open guide →Shared principles
Validate before activation
Check the manifest, file dimensions, license record, and active pointer before starting the compatibility runtime.
Keep assets local
A theme runtime should not read chats, credentials, unrelated files, or remote commands.
Make restore a first-class path
Ship and test restore instructions beside install instructions, not as an afterthought.
Practical answers
Questions worth answering before you choose.
Are Codex themes installed the same way on macOS and Windows?
The pack contract can be shared, but launch and restore scripts differ by platform. A quality pack includes platform-specific scripts while keeping the manifest, artwork, and visual tokens portable.
Will a custom background appear in Settings > Appearance?
No. Native options may appear there, but advanced artwork is provided by an unofficial loopback-only local compatibility layer. It remains separate from Codex's native theme list.
What image size should I use for Codex Desktop?
Start at 3200 × 2000 in a 16:10 landscape composition. From that source, prepare dedicated 16:10, 16:9, and 4:3 crops while preserving a quiet reading field.
Build the rest of the theme brief.
Move between visual style, workflow, and platform constraints, then use the builder to generate image guidance and preview the result.