Codex Skin Builder

Create a complete skin package, not a screenshot overlay. Preserve Codex's native DOM and interactions while changing the visual layer.

Required outcome

Deliver all of the following:

• A themed source PNG and an animated hero GIF.
• Theme CSS and renderer injection code.
• macOS install, activate, verify, and restore scripts.
• A skin.json manifest and skill metadata.
• A complete folder plus ZIP archive.
• Evidence from static validation and an isolated install/restore round trip.

Use the bundled implementation under assets/reference-skin/ as the runtime base. Do not rebuild CDP/WebSocket logic from memory unless the bundled implementation is incompatible with the installed Codex version.

Safety invariants

• Never modify, replace, re-sign, or unpack the official Codex .app or app.asar.
• Bind the debugging endpoint to 127.0.0.1; never expose it on a LAN interface.
• Keep decorative injected elements pointer-events: none.
• Provide a live cleanup path and a full base-theme restore path.
• Do not terminate or restart the user's active Codex window without explicit permission.
• Run initial installation tests with an isolated HOME and desktop directory.
• Treat reference images and linked IP as user-provided creative direction. Confirm the requested use is appropriate when redistribution rights are unclear.

Workflow

1. Inspect inputs and choose a visual system

Inspect every supplied screenshot or local image. If the user supplies a specific webpage, inspect that source too. Record:

• Character silhouette, face, markings, outline style, and expression.
• Dominant and accent colors.
• Intended mood and office/task props.
• Required negative space for native Codex copy.
• Motion opportunities that can loop quietly.

Read references/visual-workflow.md before generating artwork.

2. Generate the source artwork

Use the available image-generation skill for raster artwork. Read its SKILL.md before invoking it. Treat user images as references unless the user explicitly asks to edit one.

Generate a 16:7 or similarly wide banner with:

• The subject in the right 45–55%.
• Calm negative space in the left 40–50% for Codex text.
• No embedded words, logos, UI chrome, or watermark.
• Safe margins and a clean crop at desktop sizes.
• Character identity features locked to the user's reference.

Save the selected source PNG in the workspace. Do not leave a project asset only under the image generator's default output directory.

3. Build the animated GIF

Create restrained motion rather than a distracting video: 10–16 frames, 90–140 ms per frame, infinite loop. Prefer gentle camera drift, blinking accents, floating particles, falling coins, breathing, or a pulsing prop.

The bundled builder uses sharp and accepts input/output arguments:

NODE_PATH="<bundled-node-modules>" "<bundled-node>" \
  assets/reference-skin/scripts/build-salary-cat-gif.cjs \
  /absolute/path/source.png /absolute/path/hero.gif

Use the workspace dependency loader to locate <bundled-node> and <bundled-node-modules>. Adjust the overlay SVG in the generated package after scaffolding when the theme needs different particles or prop locations.

4. Scaffold the package

Run:

python3 scripts/scaffold_skin.py \
  --name "Codex 示例主题" \
  --slug "codex-example-skin" \
  --description "示例角色与暖色工作台主题" \
  --source /absolute/path/source.png \
  --gif /absolute/path/hero.gif \
  --output /absolute/path/codex-example-skin

Use lowercase hyphen-case for --slug. The output path must not exist. The script renames internal CSS/JS/shell identifiers, runtime state, launchers, manifest entries, and asset filenames so separately generated skins do not share the original monthly-cat identifiers.

5. Adapt the visual layer

Edit the generated assets/<key>-skin.css and assets/renderer-inject.js.

• Replace the starter palette with colors sampled from the source artwork.
• Keep selectors anchored to stable semantic hooks such as main.main-surface, aside.app-shell-left-panel, [role="main"], .composer-surface-chrome, and [data-testid="home-icon"].
• Keep the native home copy, suggestion buttons, project selector, composer, task content, and sidebar interactive.
• Use CSS/DOM for labels so raster artwork remains free of text.
• Keep the static PNG fallback under prefers-reduced-motion: reduce.
• Make mutation handling idempotent. Reapplying the payload must update existing nodes, not duplicate them.
• Update visible copy and emoji to fit the theme.

Read references/runtime-architecture.md before changing injector, launcher, or restore code.

6. Validate without disturbing the active app

Read references/qa.md and run every static and isolated test. At minimum verify:

• Shell and JavaScript syntax.
• Manifest JSON.
• PNG dimensions and GIF frame count/loop.
• Isolated install creates both .app launchers.
• Restore removes launchers and restores the prior config without deleting unrelated settings.
• The package has no absolute paths to the creator's machine.

Only run live CDP injection or restart Codex when authorized. For live validation, capture a screenshot and inspect it rather than trusting a boolean verifier alone.

7. Package and report

Create a ZIP from the complete generated folder. Report:

• The folder path.
• The ZIP path.
• The install command.
• The generated PNG/GIF paths and final image prompt.
• GIF dimensions, frame count, delay, and loop.
• Which validations passed and which live checks were not run.

Do not claim visual or live-app verification that was not actually performed.

Bundled resources

• scripts/scaffold_skin.py: Copy and rename the known-good runtime into a new theme package.
• assets/reference-skin/: Working macOS CDP implementation and animation builder.
• references/visual-workflow.md: Reference analysis, image prompt, and motion guidance.
• references/runtime-architecture.md: CDP architecture and fragile implementation points.
• references/qa.md: Static, isolated, live, restore, and packaging checks.