Appstore screenshot validator

Skill Xopoko/build-swift-apps/skills/appstore-screenshot-validator

Swift-focused AI agent skills for iOS and macOS: build, debug, simulator, SwiftUI, Xcode, App Store workflows. Part of Plug'n Skills.

Install

npx -y skills add Xopoko/build-swift-apps --skill appstore-screenshot-validator

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What its author says it does

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Resize, strip alpha, color-convert, validate, and upload App Store screenshots using current `asc screenshots` size data and macOS `sips`.

SKILL.md

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App Store Screenshot Validator

Prepare screenshots for App Store Connect. Do not hard-code Apple size tables here; asc screenshots sizes is the source of truth.

Source Of Truth

asc screenshots sizes --output table
asc screenshots sizes --all --output table

Common anchors: IPHONE_65 and IPAD_PRO_3GEN_129. Use --all for other iPhone sizes, Apple TV, Mac, Vision Pro, iMessage, or Watch.

Local Audit Helper

After choosing target dimensions from ASC, inspect local screenshots with the bundled helper:

python3 "$PLUGIN_ROOT/skills/appstore-screenshot-validator/scripts/screenshot_audit.py" \
  "./screenshots/iphone" --recursive --allow-size 1284x2778 --allow-rotated --fail-on-alpha

The helper reads PNG/JPEG headers only. It does not resize, rewrite, strip alpha, upload, or call ASC. Pass --json for machine-readable output.

Workflow

Query current screenshot size requirements with asc screenshots sizes --all.
Run screenshot_audit.py against candidate PNG/JPEG files; fail on alpha and hidden Unicode filename spaces before upload.
Preserve originals. Write sanitized, alpha-stripped, resized, or color-converted images to a separate directory.
Use sips for macOS image rewrites only after selecting an ASC target size; sips -z takes height then width.
Run asc screenshots validate on the final directory, then asc screenshots upload --dry-run, then upload only after the dry-run is clean.

Guardrails

Preserve originals by writing to a separate directory. Do not stretch across incompatible aspect ratios unless the user accepts the visual tradeoff. Prefer asc screenshots validate over visual inspection before upload.

References

references/appstore-screenshot-validator.md for detailed asc, sips, filename cleanup, validate, and upload commands.