How do I install the Appstore Screenshot Validator skill?

Run npx skillmds@latest add xopoko/appstore-screenshot-validator in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Appstore Screenshot Validator safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Appstore Screenshot Validator?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Appstore Screenshot Validator free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Appstore Screenshot Validator?

Xopoko (@xopoko) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Appstore Screenshot Validator by xopoko

Name: Appstore Screenshot Validator
Author: Xopoko

File contents

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

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.

---name: appstore-screenshot-validatordescription: App Store screenshot validation and upload with live `asc` size data and macOS `sips` to resize, strip alpha, and color-convert copies.---# App Store Screenshot ValidatorBefore 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```bashasc screenshots sizes --output tableasc screenshots sizes --all --output table```For apps that run on each device family, the current required anchors are theiPhone 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-inchscreenshots are not provided. Use `--all` for every accepted iPhone size, AppleTV, Mac, Vision Pro, iMessage, or Watch slot.## Local Audit HelperAfter choosing target dimensions from ASC, inspect local screenshots with the bundled helper:```bashpython3 "$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.## Workflow1. 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.## GuardrailsPreserve 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.

Frequently asked questions

Appstore Screenshot Validator