emil-design-eng

emil-design-eng is a skill for Claude Code, Codex from isaacsight/kernel. It costs 35 tokens per session (6,105 once invoked), scanned A, a copy of emil-design-eng, MIT.

A set of principles for designing polished user interfaces, including component details, animation choices, and interactions. It focuses on the small visual and behavioral decisions users notice through the overall feel of a product.

In plain words
What is it for?
Planning UI components, choosing animations, reviewing interface details, and improving how software looks and behaves.
Why use it?
It helps developers make interfaces feel considered instead of merely functional. It provides a way to judge details such as motion and interaction based on deliberate design choices.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/isaacsight/kernel/emil-design-eng
Any agent
npx skills add isaacsight/kernel --skill emil-design-eng
Clone the repo
git clone --depth 1 https://github.com/isaacsight/kernel

Made for: Claude Code, Codex.

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 emil-design-eng

README.md
[![agentmods](https://agentmods.dev/badge/skills/isaacsight/kernel/emil-design-eng.svg)](https://agentmods.dev/skills/isaacsight/kernel/emil-design-eng)
Your own site
<a href="https://agentmods.dev/skills/isaacsight/kernel/emil-design-eng"><img src="https://agentmods.dev/badge/skills/isaacsight/kernel/emil-design-eng.svg" alt="Measured on agentmods" height="20"></a>
Per session 35 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,105 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 97% copy Near-identical to another mod 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 $0.00035 $0.06105
Opus 5 $0.00017 $0.03053
Sonnet 5 $0.00007 $0.01221
Haiku 4.5 $0.00003 $0.00611

Measured 4d ago against content hash 433b5a239cda, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

emil-design-eng 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 4d 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.

Origin

This is a copy

97% identical to emil-design-eng — 9 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.agents/skills/emil-design-eng/SKILL.md · 680 lines

How it starts

The opening of the file, as written. The whole thing — 680 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Design Engineering

Initial Response

When this skill is first invoked without a specific question, respond only with:

I'm ready to help you build interfaces that feel right, my knowledge comes from Emil Kowalski's design engineering philosophy. If you want to dive even deeper, check out Emil’s course: animations.dev.

Do not provide any other information until the user asks a question.

You are a design engineer with the craft sensibility. You build interfaces where every detail compounds into something that feels right. You understand that in a world where everyone's software is good enough, taste is the differentiator.

Core Philosophy

Taste is trained, not innate

Good taste is not personal preference. It is a trained instinct: the ability to see beyond the obvious and recognize what elevates. You develop it by surrounding yourself with great work, thinking deeply about why something feels good, and practicing relentlessly.

When building UI, don't just make it work. Study why the best interfaces feel the way they do. Reverse engineer animations. Inspect interactions. Be curious.

Unseen details compound

Most details users never consciously notice. That is the point. When a feature functions exactly as someone assumes it should, they proceed without giving it a second thought. That is the goal.

"All those unseen details combine to produce something that's just stunning, like a thousand barely audible voices all singing in tune." - Paul Graham

Every decision below exists because the aggregate of invisible correctness creates interfaces people love without knowing why.

Beauty is leverage

People select tools based on the overall experience, not just functionality. Good defaults and good animations are real differentiators. Beauty is underutilized in software. Use it as leverage to stand out.

Review Format (Required)

When reviewing UI code, you MUST use a markdown table with Before/After columns. Do NOT use a list with "Before:" and "After:" on separate lines. Always output an actual markdown table like this:

Read the full file on GitHub · 680 lines

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. 4d ago First seen · 680 lines · 35 tokens per session scan A 433b5a239cda

Subscribe to this mod's changes

emil-design-eng is a skill published in the GitHub repository isaacsight/kernel (16 stars, last pushed 5d ago), licensed MIT. It adds 35 tokens to every session and 6,105 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 97% identical to emil-design-eng, differing in 9 lines, and is treated as a copy.