ai-essentials: Skill for Claude Code

.claude/skills/ui-diff/SKILL.md

ui-diff is a skill for Claude Code from iAmMccc/ai-essentials. It costs 142 tokens per session (2,733 once invoked), scanned A, original, no licence file.

A visual comparison tool for checking an app screenshot against its UI design. It looks at spacing, position, alignment, colors, and text size.

In plain words
What is it for?
Use it for UI reviews, checking implementation accuracy, and comparing batches of design images with app screenshots.
Why use it?
It helps find differences between the intended design and the built interface without relying only on memory or manual inspection.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is iAmMccc/ai-essentials's own configuration. It tells Claude Code how to work on ai-essentials itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything ai-essentials configures →

Reuse

Borrowing it

Nothing to install: this file belongs to iAmMccc/ai-essentials. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/iAmMccc/ai-essentials/main/.claude/skills/ui-diff/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/iAmMccc/ai-essentials

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ui-diff

README.md
[![agentmods](https://agentmods.dev/badge/skills/iammccc/ai-essentials/ui-diff/github.svg)](https://agentmods.dev/skills/iammccc/ai-essentials/ui-diff)
Your own site
<a href="https://agentmods.dev/skills/iammccc/ai-essentials/ui-diff"><img src="https://agentmods.dev/badge/skills/iammccc/ai-essentials/ui-diff/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ui-diff

Your own site · 80×15
<a href="https://agentmods.dev/skills/iammccc/ai-essentials/ui-diff"><img src="https://agentmods.dev/badge/skills/iammccc/ai-essentials/ui-diff.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 142 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,733 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00142 $0.02733
Opus 5.5 $0.00057 $0.01093
Sonnet 5.5 $0.00028 $0.00547
Haiku 4.5 $0.00014 $0.00273

Measured 1mo ago against content hash 20752c869a42, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ui-diff scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/skills/ui-diff/SKILL.md · 286 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago First seen · 286 lines · 142 tokens per session scan A 20752c869a42

Subscribe to this mod's changes

ui-diff is a skill published in the GitHub repository iAmMccc/ai-essentials (20 stars, last pushed 5mo ago), with no licence file. It adds 142 tokens to every session and 2,733 once invoked, about $0.0006 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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