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 agentmods add skills/vitorpamplona/amethyst/compose-expertnpx skills add vitorpamplona/amethyst --skill compose-expertgit clone --depth 1 https://github.com/vitorpamplona/amethystWhat 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 | $0.00098 | $0.03711 |
| Opus 5 | $0.00049 | $0.01855 |
| Sonnet 5 | $0.00020 | $0.00742 |
| Haiku 4.5 | $0.00010 | $0.00371 |
Grade A, and why
compose-expert 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 579 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Compose Multiplatform Expert
Visual UI patterns for sharing composables across Android and Desktop.
When to Use This Skill
- Creating or refactoring shared UI components
- Deciding whether to share UI in
commonMainor keep platform-specific - Building custom ImageVector icons (robohash pattern)
- State management: remember, derivedStateOf, produceState
- Recomposition optimization: visual usage of @Stable/@Immutable
- Material3 theming and styling
- Performance: lazy lists, image loading
Delegate to other skills:
- Navigation structure →
android-expert,desktop-expert - Kotlin state patterns (StateFlow, sealed classes) →
kotlin-expert - Build configuration →
gradle-expert
Philosophy: Share by Default
Default to commons/commonMain unless platform experts indicate otherwise.
Always Share
- UI components: Buttons, cards, lists, dialogs, inputs
- State visualization: Loading, empty, error states
- Custom icons: ImageVector assets (robohash, custom paths)
- Theme utilities: Color calculations, style helpers
- Material3 components: Any UI using Material primitives
Keep Platform-Specific
- Navigation structure: Bottom nav (Android) vs Sidebar (Desktop)
- Screen layouts: Platform-specific scaffolding
- System integrations: File pickers, notifications, share sheets
- Platform UX: Gestures, keyboard shortcuts, window management
Decision Framework
- Uses only Material3 primitives? → Share in
commonMain - Requires platform system APIs? → Platform-specific
- Pure visual component without navigation? → Share in
commonMain - Needs platform UX patterns? → Ask
android-expertordesktop-expert
If uncertain, default to sharing - easier to split later than merge.
Shared Composable Anatomy
Structure
@Composable
fun SharedComponent(
// State parameters (read-only)
data: DataClass,
isLoading: Boolean,
// Event parameters (write-only)
onAction: () -> Unit,
// Visual parameters
modifier: Modifier = Modifier,
// Optional customization
colors: ComponentColors = ComponentDefaults.colors()
) {
// Implementation
}
What ships with it
5 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.
- yesterday First seen · 579 lines · 98 tokens per session scan A 4c3e68fffcca
compose-expert is a skill published in the GitHub repository vitorpamplona/amethyst (1,593 stars, last pushed yesterday), licensed MIT. It adds 98 tokens to every session and 3,711 once invoked, about $0.0005 per session on Opus 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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