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 jxoesneon/Ciel --skill animate-expogit clone --depth 1 https://github.com/jxoesneon/CielWrote 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/jxoesneon/ciel/animate-expo)<a href="https://agentmods.dev/skills/jxoesneon/ciel/animate-expo"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/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/jxoesneon/ciel/animate-expo"><img src="https://agentmods.dev/badge/skills/jxoesneon/ciel/animate-expo.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.04349 |
| Opus 5.5 | $0.00045 | $0.01740 |
| Sonnet 5.5 | $0.00022 | $0.00870 |
| Haiku 4.5 | $0.00011 | $0.00435 |
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 20d 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.
This is a copy
97% identical to animate-expo — 4 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.
How it starts
The opening of the file, as written. The whole thing — 268 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
2 files 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.
- 20d ago First seen · 268 lines · 112 tokens per session scan A 4e8839a79047
animate-expo is a skill published in the GitHub repository jxoesneon/Ciel (1 stars, last pushed 4d ago), licensed Apache-2.0. It adds 112 tokens to every session and 4,349 once invoked, about $0.0004 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 97% identical to animate-expo, differing in 4 lines, and is treated as a copy.
Other skills, from other repositories
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mobile-design-system-foundation
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mobile-ui-ux
Use when designing or building any mobile screen or component a user sees (Flutter, SwiftUI or Compose) - platform conventions, hierarchy, type that scales, colour roles and dark mode, safe areas and insets, forms and keyboard, states, feedback, and the generic-mobile anti-patterns.
mobile-accessibility
Use when building or changing any interactive mobile UI - VoiceOver/TalkBack labels, grouping, headings, focus order, Dynamic Type/font scale, reduce motion, contrast, and the automated check for each stack.
flutter-atomic-components
Use when adding or reusing Flutter UI - organize widgets as atoms, molecules, and organisms in a shared library and never hand-roll a component that already exists.
android-ui-engineering
Use when building UI with Jetpack Compose. Covers component design, state hoisting, recomposition optimization, Material 3 theming, Navigation 3, adaptive layouts for large screens, previews, screenshot verification, and XML interop.