Codex Theme Studio

Codex Theme Studio

Build themes as data and image packages while reusing the supplied Windows launcher and CDP injection engine.

Workflow

1. Confirm the target is the Windows Store Codex desktop app.
2. Inspect the requested visual direction and choose a rights mode from references/rights-modes.md.
3. Create a theme folder from the schema in references/theme-package.md.
4. Choose a compact or immersive hero layout and composer palette using references/theme-package.md.
5. Generate the four required raster assets: hero, left corner, right corner, and square icon. Add a separate chat-background.png when the user wants full-window chat artwork; follow references/image-generation.md and never stretch the wide hero into the chat surface.
6. Run node scripts/validate-theme.mjs --theme <theme-folder>.
7. Run powershell -ExecutionPolicy Bypass -File scripts/install-theme.ps1 -ThemePath <theme-folder>.
8. Launch the created desktop shortcut or run scripts/start-theme.ps1 directly.
9. Verify the home and chat views separately with scripts/verify-theme.ps1, including screenshots when visual QA is needed.
10. Test scripts/restore-theme.ps1, then reapply the theme if the user wants it left active.

Image generation

Use the built-in image generation capability by default. Read references/image-generation.md before generating assets. Keep all UI text in the manifest; generated images should normally contain no text.

For transparent corner decorations, generate each asset on a flat chroma-key background, remove that color, and inspect the PNG edges. Do not fake transparency with white backgrounds.

Theme packaging

Keep every theme self-contained:

my-theme/
├── theme.json
├── theme.css         # optional theme-specific visual overrides
├── hero.png
├── chat-background.png # optional measured-ratio chat background
├── corner-left.png
├── corner-right.png
├── icon.png
└── icon.ico          # generated during installation when absent

Do not edit assets/base-theme.css for ordinary themes. Change it only when adding a capability that every theme package should inherit. Put theme-specific chat backgrounds, decoration placement, opacity, and other visual overrides in the optional theme.css; it loads after the shared CSS and must use the supplied --theme-* variables instead of external resources.

Install and switch

Validate assets and create themed shortcuts:

powershell -ExecutionPolicy Bypass -File scripts/install-theme.ps1 -ThemePath "C:\path\to\my-theme"

Start or switch themes in the isolated Theme Studio profile:

powershell -ExecutionPolicy Bypass -File scripts/start-theme.ps1 `
  -ThemePath "C:\path\to\my-theme" `
  -ProfilePath "$env:LOCALAPPDATA\CodexThemeStudio\profile"

Generated shortcuts always use a separate Theme Studio profile and never edit ~/.codex/config.toml, so normally launched Codex windows keep their default appearance. Use -RestartExisting only for legacy direct launches without -ProfilePath, after the user has saved current work and authorized restarting the app.

Verify and recover

Run structural verification and capture the current window:

powershell -ExecutionPolicy Bypass -File scripts/verify-theme.ps1 `
  -ThemePath "C:\path\to\my-theme" `
  -View Home `
  -Screenshot "C:\path\to\qa.png"

powershell -ExecutionPolicy Bypass -File scripts/verify-theme.ps1 `
  -ThemePath "C:\path\to\my-theme" `
  -View Chat

Always verify:

• The home hero and one to four action cards fit the viewport.
• Immersive hero cards remain inside the background area and the composer starts below it.
• The chat view retains readable contrast and usable composer controls.
• Tool summaries, file-change rows, timestamps, tertiary labels, and loading text use the theme ink or muted color; do not validate only Markdown paragraphs.
• A dedicated chat background fills the main surface with cover, does not stretch or collapse into a horizontal band, and preserves its subject and text-safe region.
• The chat background remains visible through the content viewport, and at least one corner decoration is visibly rendered.
• Composer background, border, text, caret, and send button follow the theme palette.
• The desktop shortcut uses the theme .ico, not the PowerShell icon.
• Restore removes the live injection.
• Reapplying the same theme is idempotent.

Remove the live theme:

powershell -ExecutionPolicy Bypass -File scripts/restore-theme.ps1

Add -RestoreBaseTheme only to clean up a global palette left by Theme Studio versions that predate profile isolation; reopen Codex afterward. Add -Uninstall -ThemePath <folder> to remove shortcuts for one theme. Never delete the theme folder automatically.

Failure handling

• If the validator fails, fix the manifest or missing assets before touching Codex.
• If the debug port is unavailable, do not launch the WindowsApps executable directly; use start-theme.ps1.
• If verification fails, inspect %LOCALAPPDATA%\CodexThemeStudio\injector-error.log.
• If a Codex update changes the DOM, keep the theme package unchanged and repair only the shared renderer/CSS engine.
• Never edit the global Codex config during normal install, start, switch, or restore flows.