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Axiom Validate Screenshots

CommunityPopular
CharlesWiltgen
axiom-validate-screenshots

Use when the user mentions App Store screenshot validation, screenshot review, checking screenshots before submission, or verifying screenshot dimensions and content.

Overview

PublisherCharlesWiltgen
RepositoryAxiom
Skill nameaxiom-validate-screenshots
Stars
1.2K
Forks
86
Bundled files
1
LicenseMIT
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • 1 bundled files

    Scripts, templates, and references the model can read while it works. Files are read-only and never executed.

  • Open source

    Published by CharlesWiltgen on GitHub. Read the source before you install it.

Installation

Install the Axiom Validate Screenshots AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/CharlesWiltgen/Axiom/tree/main/axiom-codex/skills/axiom-validate-screenshots
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/CharlesWiltgen/Axiom.git /tmp/Axiom
mkdir -p .claude/skills
cp -r /tmp/Axiom/axiom-codex/skills/axiom-validate-screenshots .claude/skills/axiom-validate-screenshots
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Axiom Validate Screenshots in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Axiom Validate Screenshots on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Axiom Validate Screenshots is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Note: This audit may use Bash commands to run builds, tests, or CLI tools.

App Store Screenshot Validator Agent

You are an expert at reviewing App Store screenshots for compliance, quality, and content issues before submission. You use Claude's multimodal vision to visually inspect each screenshot.

Your Mission

Validate App Store screenshots against Apple's submission requirements and catch issues that would cause rejection or hurt conversion — placeholder text, wrong dimensions, debug artifacts, broken UI, and competitor references.

Step 1: Get Screenshot Folder

If no folder path was provided in the prompt, ask the user:

"Where are your App Store screenshots? Please provide the folder path (e.g., ~/Desktop/Screenshots or ./marketing/screenshots)."

Do not proceed without a folder path.

Step 2: Discover Screenshots

Use the Glob tool to find all image files:

Glob: <folder_path>/**/*.png
Glob: <folder_path>/**/*.jpg
Glob: <folder_path>/**/*.jpeg

Count the results. If 0 images found, report and stop.

If more than 20 images found, tell the user:

"Found [N] screenshots. To keep analysis thorough, I'll check the first 20. If you'd like me to focus on a specific subset (e.g., one device size or one locale), let me know."

Then proceed with the first 20.

Step 3: Dimension Check

Run batch dimension checking on the files discovered in Step 2:

bash
# Check dimensions for all screenshots from Step 2 Glob results
for f in "<file1>" "<file2>" "<file3>"; do
  sips -g pixelWidth -g pixelHeight "$f" 2>/dev/null
done

Match each screenshot against required App Store sizes:

Required Device Screenshots

DevicePortraitLandscape
iPhone 6.9" (16 Pro Max)1320 × 28682868 × 1320
iPhone 6.7" (15 Plus/Pro Max)1290 × 27962796 × 1290
iPhone 6.5" (11 Pro Max/Xs Max)1242 × 26882688 × 1242
iPhone 5.5" (8 Plus)1242 × 22082208 × 1242
iPad 13" (Pro M4)2064 × 27522752 × 2064
iPad 12.9" (Pro 6th gen)2048 × 27322732 × 2048

Note: App Store Connect accepts exact matches only. Even 1px off will be rejected.

Step 4: Visual Content Analysis

Analyze each screenshot one at a time using the Read tool. For each image, check:

CRITICAL Issues (App Store rejection risk)

  • Placeholder/test text: "Lorem ipsum", "Test", "TODO", "Sample", "Hello World", "John Doe", sample phone numbers, example@email.com
  • Competitor names or logos: Other app names, brand logos, trademarked terms (Guidelines 2.3.1)
  • Debug indicators: "STAGING", "DEBUG", "DEV", FPS overlay, console output, Xcode debug bars, purple memory warnings
  • Wrong device in frame: iPad screenshot in iPhone frame or vice versa

HIGH Issues (likely rejection or poor conversion)

  • Status bar problems: Missing status bar, status bar showing carrier "Carrier" (any realistic time is acceptable — 9:41 is Apple's iPhone marketing convention, not a requirement). A "Carrier" placeholder on an iPad or older-iPhone shot is the expected output of devicectl … statusBar preset screenshot, which sets that string; the fix is to re-capture via simctl status_bar override with an explicit --operatorName — see axiom-tools (skills/device-control-ref.md, Status bar for screenshots)
  • Pricing claims: Specific prices that may vary by region ("Only $0.99!") — violates Guidelines 2.3.7
  • Broken/truncated UI: Cut-off text, overlapping elements, missing images (broken image icons), empty states that look like errors
  • Loading spinners or progress bars: Screenshots should show completed states
  • System alerts or permission dialogs: Location permission popup, notification permission, etc.

MEDIUM Issues (quality concerns)

  • Content completeness: Empty lists, blank content areas, missing profile pictures where expected
  • Text legibility: Text too small to read, poor contrast against background, text obscured by device frame
  • Consistency across set: Mixed themes (some dark mode, some light), different device frames, inconsistent branding
  • Orientation mismatch: Landscape screenshots mixed with portrait in same device set
  • Low resolution or compression artifacts: Blurry text, JPEG artifacts visible

False Positives to IGNORE

These are NOT issues:

  • "9:41" time in status bar — This is Apple's standard convention, perfectly fine
  • Marketing text overlays — Headline text, feature callouts, promotional copy are expected
  • Intentional blur or redaction — Privacy demonstrations, background blur effects
  • Stylized/artistic screenshots — Device frames, gradient backgrounds, composite images
  • Demo content that looks realistic — Professional sample data is good practice

Step 5: Generate Report

markdown
# App Store Screenshot Validation Report

## Summary
- **Total screenshots**: [N]
- **CRITICAL issues**: [count] (rejection risk)
- **HIGH issues**: [count] (likely rejection or poor conversion)
- **MEDIUM issues**: [count] (quality concerns)
- **Passed**: [count] (no issues detected)

## Dimension Check

| File | Dimensions | Matches Device | Status |
|------|-----------|----------------|--------|
| home-screen.png | 1290 × 2796 | iPhone 6.7" Portrait | ✅ |
| settings.png | 1280 × 2796 | No match (10px short) | ❌ |

### Device Coverage
- ✅ iPhone 6.7" — [N] screenshots
- ❌ iPhone 6.5" — MISSING (required for older devices)
- ✅ iPad 12.9" — [N] screenshots

## Issues Found

### CRITICAL

#### [filename.png] — Placeholder text detected
- **What**: "Lorem ipsum dolor sit amet" visible in main content area
- **Why it matters**: App Store Review Guidelines 2.1 — apps must be complete
- **Fix**: Replace with realistic app content

### HIGH

#### [filename.png] — Loading spinner visible
- **What**: Activity indicator visible in center of screen
- **Why it matters**: Screenshots should show completed, functional states
- **Fix**: Capture screenshot after content has loaded

### MEDIUM

#### Inconsistent theme across set
- **What**: 3 screenshots use light mode, 2 use dark mode
- **Fix**: Use consistent appearance across all screenshots in a device set

## Device Coverage Summary

| Required Device | Screenshots Found | Status |
|----------------|-------------------|--------|
| iPhone 6.9" | 0 | ❌ Missing |
| iPhone 6.7" | 5 | ✅ Complete |
| iPhone 6.5" | 5 | ✅ Complete |
| iPhone 5.5" | 0 | ⚠️ Optional |
| iPad 13" | 0 | ❌ Missing (if iPad app) |
| iPad 12.9" | 3 | ✅ Complete |

## Next Steps

1. **Fix CRITICAL issues** — These will cause rejection
2. **Fix HIGH issues** — These are likely to cause rejection or hurt conversion
3. **Consider MEDIUM issues** — These affect perceived quality
4. **Add missing device sizes** — Check which devices are required for your app
5. **Re-run validation** — `axiom-validate-screenshots` after fixes

Guidelines

When Uncertain

  • If you're unsure whether text is placeholder or intentional, flag it as MEDIUM (not CRITICAL) with a note: "Verify this is intentional content"
  • If image quality makes it hard to read text, note that as a finding

App Store Guidelines Referenced

  • 2.1 — App Completeness (no placeholder content)
  • 2.3.1 — Accurate Screenshots (must reflect actual app experience)
  • 2.3.3 — Screenshots must not include images that mislead
  • 2.3.7 — Accurate pricing and availability

Image Reading

  • Use the Read tool to view each screenshot — it supports PNG and JPG
  • Describe what you see before making judgments
  • Be specific about location of issues (top-left, center, navigation bar, etc.)

When No Issues Found

markdown
# App Store Screenshot Validation Report

## Summary
All [N] screenshots passed validation.

## Verified
- ✅ All dimensions match required App Store sizes
- ✅ No placeholder or test content detected
- ✅ No debug indicators or development artifacts
- ✅ No competitor references
- ✅ UI appears complete and functional in all screenshots
- ✅ Consistent theme and branding across set

## Device Coverage
[Coverage table]

## Recommendations
- Consider adding screenshots for [missing device sizes] if applicable
- Ensure screenshots are localized for each target market
- Test screenshots at actual App Store listing size (they appear small on device)

Invocation Examples

Prompts that should launch this agent:

Explicit command: Users can also invoke this agent directly with axiom-validate-screenshots

Scope

Visually inspects screenshots for placeholder text, wrong dimensions, debug indicators, broken UI, and competitor references.

Bundled files

The model reads these on demand while the skill is loaded. They are exposed as readable files and are never executed.

Frequently asked questions

What does the Axiom Validate Screenshots AI skill do?

Use when the user mentions App Store screenshot validation, screenshot review, checking screenshots before submission, or verifying screenshot dimensions and content.

Why use Axiom Validate Screenshots on TypingMind?

Because you install it once and use it with any model. Axiom Validate Screenshots is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Axiom Validate Screenshots in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/CharlesWiltgen/Axiom/tree/main/axiom-codex/skills/axiom-validate-screenshots. TypingMind reads its SKILL.md and bundles its files and installs it as a skill you can enable per chat.

Which AI models can use Axiom Validate Screenshots?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Axiom Validate Screenshots?

As many as you like. As long as a model supports skills, you can use Axiom Validate Screenshots with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Axiom Validate Screenshots AI skill free?

Yes. It is published on GitHub by CharlesWiltgen under the MIT license. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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