Chrome Webstore Image Generator

Generate Chrome Web Store listing images from one or more source files and validate them before submission.

Quick Start

1. Collect absolute paths for one or more source images, or auto-capture screenshots from an unpacked extension.
2. Generate assets with scripts/generate_store_assets.py.
3. Validate output with scripts/validate_store_assets.py.

Auto-Capture Screenshots (Optional)

Capture popup/options/page screenshots directly into release/store-assets/screenshots:

python3 -m pip install playwright
python3 -m playwright install chromium

python3 scripts/capture_extension_screenshots.py \
  --extension-root /abs/path/to/unpacked-extension \
  --root /abs/project/release/store-assets \
  --options-path options.html \
  --urls https://example.com https://news.ycombinator.com

Then generate remaining assets (icon/small promo/marquee) using explicit icon input:

python3 scripts/generate_store_assets.py \
  --inputs /abs/project/release/store-assets/screenshots/*.png \
  --icon-source /abs/path/icon.png \
  --root /abs/project/release/store-assets \
  --include-marquee

Generate Assets

Run from the skill directory:

python3 scripts/generate_store_assets.py \
  --inputs /abs/path/source-1.png /abs/path/source-2.jpg \
  --icon-source /abs/path/icon.png \
  --root /abs/project/release/store-assets \
  --include-marquee

Default behavior:

• Auto-pick icon source for icon-128x128.png from files with icon/logo-like names or near-square dimensions.
• Use the first input for small-promo-440x280.png unless --small-promo-source is provided.
• Use up to 5 non-icon input images for screenshots/screenshot-<index>-<width>x<height>.png (falls back to all inputs when needed).
• Append screenshots by default (keep existing files and continue numbering when slots remain).
• Produce screenshots at 1280x800 by default.
• Generate marquee-1400x560.png only when --include-marquee is set.
• If icon inference is ambiguous (for example, a single screenshot-like input), generation fails fast and requires --icon-source.

Useful options:

• --screenshot-size 640x400: switch screenshot size to 640x400.
• --max-screenshots 3: limit generated screenshots.
• --overwrite-screenshots: clear existing screenshots and regenerate from screenshot-1-*.
• --append-screenshots: compatibility flag (append is already default).
• --icon-source: explicitly set icon input (recommended and safest).
• --allow-icon-fallback: allow legacy single-input fallback (only when intentional).
• --small-promo-source, --marquee-source: override other output source images.

Validate Assets

python3 scripts/validate_store_assets.py --root /abs/project/release/store-assets

Validation checks:

• icon-128x128: exactly 128x128 and format PNG
• small-promo-440x280: exactly 440x280
• marquee-1400x560: exactly 1400x560 (optional)
• Screenshots: count 1-5, each 1280x800 or 640x400

Source Specs

Read size and naming requirements in:

• references/cws-image-specs.md

Notes

• This skill currently uses macOS sips for resizing/cropping.
• capture_extension_screenshots.py requires Python Playwright (pip install playwright) and browser install (playwright install chromium).
• If user uploads images in chat, first resolve them to accessible local file paths, then pass those paths to the script.