Appstore screenshot validator

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

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

Install

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

Assembled from the repository path, not quoted from the project. Check it against their README if it does not work.

One thing to look at

runs commandsInstructs the agent to run 8 commands, including `asc screenshots sizes --output table` and 7 more.

SKILL.md

2.0 KB, 418 tokens by cl100k_base, as published. Nobody here has run it

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.

What ships with it: 1 file

9.5 KB alongside SKILL.md, 1 of them executable

scripts/

screenshot_audit.pyruns9.5 KB

Gives 0 of the 12 instructions most quality gates skills give in 418 tokens

Counted across 1,524 of the 2,830 authors here whose files we hold, read 2026-09-06

Read full output and check exit codein 45 of 1524, across 40 files
Verify output confirms the claimin 44 of 1524, across 39 files
Identify the command that proves the claimin 43 of 1524, across 39 files
Execute the full verification commandin 36 of 1524, across 30 files
Produce a verification reportin 34 of 1524, across 18 files
Review git diff changesin 30 of 1524, across 16 files
Fix build failures immediatelyin 29 of 1524, across 9 files
Group findings by severityin 28 of 1524
State claim only with evidencein 27 of 1524, across 22 files
Verify regression tests with red-green cyclein 26 of 1524, across 22 files
Run the full test suitein 26 of 1524, across 25 files
Run test suite with coveragein 25 of 1524, across 10 files

Said here and by no other author read

Confirm execution context is macOS
Query requirements with asc screenshots sizes
Run screenshot audit on candidate files
Write processed images to separate directory
Use sips for image resizing
Validate directory with asc screenshots validate

Grouped from the skills themselves: near-identical wordings counted once, and counted by distinct author, so one author publishing three of these counts once. Length counted with cl100k_base; the agent that loads this file may tokenize it differently.