Coding agents can build a working interface but often get the small things wrong: an ease-in curve on an element that is entering, a solid border where a soft shadow belongs, a fade-in on every section. Emil Kowalski, a design engineer who has worked at Vercel and Linear and made the Sonner toast library, wrote down those small decisions as agent skills, so your agent knows the rule and the reason behind it.
There are 19 skills in plain Markdown. emil-design-eng is the main one, mostly about animation with some general design advice. Others build an animation from scratch, review or audit the animations you have, find places that would benefit from motion, remove the ones you do not need, coordinate several moving elements, fix dropped frames, build drag and swipe gestures, apply Apple's interface principles, make a web app feel native on a phone, stress-test a UI with awkward data and turn your design corrections into rules in a DESIGN.md file. Each skill has a page on aiforui.dev with examples and prompts.
The skills are MIT-licensed, with about 57,000 stars since March 2026. The same site sells Emil's paid course, AI for Designers and Engineers, which the skills come out of; you do not need it to use them.
- Repository: github.com/emilkowalski/skills
- Licence: MIT (MIT License)
- Language: Markdown. Stars: 56.6K. Forks: 3,310. Last push: Nov 13, 2026.
- Scan: safe, Nov 13, 2026, commit f7ce8c0
Who it is for
Front-end developers and design engineers who build UI with Claude Code, Cursor or Codex, designers who prototype with an agent, and anyone whose AI-built interfaces feel a little generic.
Getting started
1. Install the skills into your coding agent (Node 18 or later)
npx skills@latest add emilkowalski/skills2. Then ask in plain words, for example
Review the animations in this popover and tell me what you would change.3. Browse every skill with examples and prompts to try
https://aiforui.dev/skillsSafety scan
We cloned emilkowalski/skills at commit f7ce8c0 on Nov 13, 2026 and ran the checks described on the GitHub Tools page: credential patterns, decode-and-execute code, install-time scripts, committed binaries, risky CI workflows, every host the code talks to, known vulnerabilities in pinned dependencies, and project hygiene. A person read every hit. This is what we found.
- No secret hits, no pattern hits, no binaries and no lockfiles across 35 files and about 5,900 lines. Everything is Markdown: the skills, two cheat sheets and the README. There is no code to run and no hosts in the source.
- The extra pass for skill repos was clean. The hidden characters are zero-width spaces in front of code fences in one plan template, a common trick to stop nested fences closing early, and an emoji joiner in test data meant to break UIs. The injection phrases are defensive rules telling the agent to treat repository content as data and flag anything that tries to steer it. No exfiltration hosts, credential paths, pipe-to-shell or hook files.
- No workflows, security policy or contributing guide; it is a small project with three contributors. A licence file is present.
- The skills link to aiforui.dev, which also sells Emil's paid course and asks for an email for a newsletter. Nothing in the skills sends data there.
What the scanner counted
| Check | Result |
|---|---|
| Secrets | None found. |
| Suspicious code | None found. |
| Install-time code | None: nothing runs at install beyond the package manager itself. |
| Committed binaries | None. |
| CI workflows | No GitHub Actions workflows. |
| Network hosts | 0 distinct hosts referenced from source. No URLs to bare IP addresses. |
| Known vulnerabilities | No lockfile to check: dependencies are declared as ranges, so what gets installed is whatever is current on the day. |
| Project hygiene | Has licence file. Missing security policy, automated dependency updates, CodeQL, contributing guide. |
| OpenSSF Scorecard | Not scored: the project is not in Scorecard's weekly index. |
By the numbers
| Stars | 56.6K |
|---|---|
| Forks | 3,310 |
| Contributors | 3 |
| Commits | 66 |
| Open issues | 2 |
| Open pull requests | 1 |
| Releases | 0 |
| Latest release | none tagged |
| Licence | MIT |
| Main language | Markdown |
| Project age | 8 months |
| Last push | Nov 13, 2026 |
| Tracked files | 35 |
| Lines of code | 5,853 |
| Checkout size | 358 KB |
Lines by language: Markdown 5,853.
Questions
Are Emil Kowalski's skills free?
Yes. The skills are free and MIT-licensed. The paid course on the same site is separate and optional.
Which agents do they work with?
Any agent that reads Agent Skills, including Claude Code, Codex and Cursor. The skills CLI copies them into the right folder for the agents you choose.
Are they only about animation?
Mostly, but not only. Skills also cover picking a UI library, prototyping several versions, mobile web polish, stress-testing layouts with bad data, Apple's design principles and recording your own design rules.
This post is part of GitHub Tools, where every repository is cloned and scanned before it is written up. The scan is a snapshot of one commit on one day; the repository has moved on since, so check it before you install.