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/android-expertnpx skills add vitorpamplona/amethyst --skill android-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 | $0.00149 | $0.06147 |
| Opus 5 | $0.00075 | $0.03073 |
| Sonnet 5 | $0.00030 | $0.01229 |
| Haiku 4.5 | $0.00015 | $0.00615 |
Grade A, and why
android-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 — 977 lines — stays where its author put it; the contents beside it link to each section on GitHub.
android-expert
Android platform expertise for Amethyst Multiplatform project. Covers Compose Navigation, Material3, permissions, lifecycle, and Android-specific patterns in KMP architecture.
When to Use
Auto-invoke when working with:
- Android navigation (Navigation Compose, routes, bottom nav)
- Runtime permissions (camera, notifications, biometric)
- Platform APIs (Intent, Context, Activity)
- Material3 theming and edge-to-edge UI
- Android build configuration (Proguard, APK optimization)
- AndroidManifest.xml configuration
- Android lifecycle (ViewModel, collectAsStateWithLifecycle)
Core Mental Model
Single Activity Architecture + Compose Navigation
MainActivity (Single Entry Point)
├── enableEdgeToEdge()
├── AmethystTheme { }
└── NavHost
├── Route.Home → HomeScreen
├── Route.Profile(id) → ProfileScreen
└── Route.Settings → SettingsScreen
Intent Filters (11+)
├── ACTION_MAIN (launcher)
├── ACTION_SEND (share)
├── ACTION_VIEW (deep links: nostr://, https://...)
└── NFC_ACTION_NDEF_DISCOVERED
Key Principles:
- Type-Safe Navigation - @Serializable routes, no strings
- Declarative Permissions - Request contextually with Accompanist
- Edge-to-Edge + Insets - Scaffold handles system bars
- ViewModel + Flow → State - Survive config changes
- Platform Isolation - Android code in
amethyst/module orandroidMain/
Architecture Overview
Module Structure
amethyst/ # Android app module
├── src/
│ ├── main/
│ │ ├── java/com/vitorpamplona/amethyst/
│ │ │ ├── ui/
│ │ │ │ ├── MainActivity.kt # Entry point
│ │ │ │ ├── navigation/
│ │ │ │ │ ├── AppNavigation.kt # NavHost
│ │ │ │ │ ├── routes/Routes.kt # @Serializable routes
│ │ │ │ │ └── bottombars/AppBottomBar.kt
│ │ │ │ ├── screen/ # 80+ screens
│ │ │ │ └── theme/Theme.kt # Material3 theme
│ │ │ └── Amethyst.kt # Application class
│ │ └── AndroidManifest.xml # Permissions, intent filters
│ └── androidMain/ # KMP Android source set
│ └── kotlin/ # Platform-specific code
└── build.gradle # Android config
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 · 977 lines · 149 tokens per session scan A 2728ae96e8bf
android-expert is a skill published in the GitHub repository vitorpamplona/amethyst (1,593 stars, last pushed yesterday), licensed MIT. It adds 149 tokens to every session and 6,147 once invoked, about $0.0007 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.
Other skills, from other repositories
sceneview
Build 3D and AR apps with the SceneView SDK in Jetpack Compose, SwiftUI (iOS/macOS/visionOS via SceneViewSwift), Web (Filament.js), Flutter and React Native. Use whenever the user asks for "3D in Compose", "AR with ARCore in Compose", a model viewer, or any cross-platform 3D/AR app where the dependency is…
sceneview-ios
Build 3D and AR apps on Apple platforms (iOS, macOS, visionOS) with SceneViewSwift — the SwiftUI wrapper around RealityKit. Use whenever the user asks for "3D in SwiftUI", "AR with ARKit in SwiftUI", a model viewer for iOS, or any Apple-platform 3D/AR app where the dependency is the SceneViewSwift Swift Package from…
to-plan
Use when one ready GitHub issue or an in-chat task needs a repository-aware implementation plan for a later implementation workflow.
compose-animations
Use when writing or reviewing Jetpack Compose motion: visibility enter/exit, animating one property toward a target, color or size transitions, multiple properties from one state, switching composable content, or choosing between AnimatedVisibility, animateAsState, rememberTransition, AnimatedContent, and Crossfade.
compose-focus-navigation
Use when writing or reviewing Jetpack Compose UI for TV, keyboard, desktop, accessibility focus, D-pad navigation, FocusRequester, focusProperties, key events, or initial focus behavior.
kotlin-control-flow
Use when writing or reviewing Kotlin branching and control flow: when expressions, guard conditions, sealed type exhaustiveness, smart casts, nullable branching, early returns, or replacing complex if/else chains.