emilkowalski/skills is a collection of guidance for coding agents that helps them make better interface and animation decisions. Designers and engineers use the skills to choose more appropriate motion, styling, and interaction details when building user interfaces. The catalogue entries are examples of the project's agent skills.
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.
npx skills add emilkowalski/skills --skill animate-expogit clone --depth 1 https://github.com/emilkowalski/skillsWrote 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.
[](https://agentmods.dev/skills/emilkowalski/skills/animate-expo)<a href="https://agentmods.dev/skills/emilkowalski/skills/animate-expo"><img src="https://agentmods.dev/badge/skills/emilkowalski/skills/animate-expo/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.
<a href="https://agentmods.dev/skills/emilkowalski/skills/animate-expo"><img src="https://agentmods.dev/badge/skills/emilkowalski/skills/animate-expo.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- Socket pass
- Snyk pass
- NVIDIA SkillSpector warn
SkillSpector: 3 findings, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium MCP Rug Pull · line 76 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium MCP Rug Pull · line 202 npx commands without a version suffix (e.g. @1.0.0) create a rug-pull risk if the upstream server is compromised and publishes a malicious update.Fix: Pin the version: npx @scope/[email protected]
- medium Rogue Agent · line 212 Skill establishes unauthorized persistence across sessions via cron jobs, startup scripts, or state files. Session persistence allows an attacker to maintain access beyond the current interaction.Fix: Remove any persistence mechanisms (cron jobs, startup scripts, state files). Skills should not maintain state across sessions without explicit user consent.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00112 | $0.04325 |
| Opus 5.5 | $0.00045 | $0.01730 |
| Sonnet 5.5 | $0.00022 | $0.00865 |
| Haiku 4.5 | $0.00011 | $0.00432 |
Grade A, and why
animate-expo 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.
Copies of this mod
3 near-identical copies found in the catalogue:
- animate-expo — 97% identical, 4 lines differ
- expo-animation — 95% identical, 31 lines differ
- animate-expo — 91% identical, 34 lines differ
How it starts
The opening of the file, as written. The whole thing — 264 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Building Animations in Expo
Initial Response
When this skill is first invoked without a specific question, respond only with:
I'm ready to build animations in Expo and React Native that feel right on a real device, my knowledge comes from Emil Kowalski's animation philosophy.
Do not provide any other information until the user asks a question.
A construction skill for React Native. It turns a request for motion into an implementation that survives a strict review on a real device — not in the simulator, not on a flagship phone in dev mode.
Mobile changes three things about animation, and everything in this skill follows from them:
- There is no hover. Every affordance the web puts in hover has to live in press, position, or nothing.
- There are two runtimes. Worklets (Reanimated 4) makes this explicit: the React Native runtime, where React renders and your app logic runs, and the UI runtime, where worklets run every frame (plus optional worker runtimes for background work). An animation that touches the RN runtime stutters the moment the app does anything else. The whole craft is keeping motion on the UI runtime.
- The user's finger is on the element. Gestures are the primary input, so interruptibility and velocity handoff aren't polish — they're the baseline.
Operating Posture
You are a senior mobile engineer building the animation yourself. Make the call, state the reasoning in one line, write the code. Never present motion options as a menu.
Two failure modes, and the first is worse:
- Animating something that shouldn't animate. The gate below exists to produce zero lines of code sometimes.
- Animating the right thing on the wrong thread — a
setStateper frame, aPanResponder, an animatedheight. It looks fine in dev on your phone and drops to 20fps on a three-year-old Android.
Hard Rules
- Run the sequence in order. Steps 1 and 2 gate everything.
- Reanimated, not core
Animated. CoreAnimatedcan't be driven by a gesture without crossing the bridge, anduseNativeDriverrefuses anything but transform and opacity anyway. Reanimated worklets run on the UI thread and keep running while JS is busy. - No approximated values. Curves and spring configs come from the tables below.
- Reduced motion ships with the animation, not as a follow-up.
- Feel is judged on a release build on the slowest device you support. Nothing else counts as verified.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 1mo ago Changed · +8 lines 9a01a91701e6
- 1mo ago First seen · 256 lines · 112 tokens per session scan A 2121fc72ffa4
animate-expo is a skill published in the GitHub repository emilkowalski/skills (50,763 stars, last pushed 16d ago), licensed MIT. It adds 112 tokens to every session and 4,325 once invoked, about $0.0004 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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