App Store Screenshot Validator

Before invoking Apple-only binaries, confirm the execution context is macOS. From Windows or Linux, run those steps in a Mac SSH project or through an already configured remote transport; do not retry missing Apple binaries locally.

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

For apps that run on each device family, the current required anchors are the iPhone 6.9-inch slot (IPHONE_69) and iPad 13-inch slot (IPAD_PRO_3GEN_129). Apple accepts the iPhone 6.5-inch slot when 6.9-inch screenshots are not provided. Use --all for every accepted iPhone size, Apple TV, Mac, Vision Pro, iMessage, or Watch slot.

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 1290x2796 --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

1. Query current screenshot size requirements with asc screenshots sizes --all.
2. Run screenshot_audit.py against candidate PNG/JPEG files; fail on alpha and hidden Unicode filename spaces before upload.
3. Preserve originals. Write sanitized, alpha-stripped, resized, or color-converted images to a separate directory.
4. Use sips for macOS image rewrites only after selecting an ASC target size; sips -z takes height then width.
5. 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.