Borrowing it
Nothing to install: this file belongs to chama-x/GroundRules. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/chama-x/GroundRules/master/.agents/archive/v3/skill_platform-design-skills/skills/android/SKILL.mdgit clone --depth 1 https://github.com/chama-x/GroundRulesWrote 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/chama-x/groundrules/android)<a href="https://agentmods.dev/skills/chama-x/groundrules/android"><img src="https://agentmods.dev/badge/skills/chama-x/groundrules/android/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/chama-x/groundrules/android"><img src="https://agentmods.dev/badge/skills/chama-x/groundrules/android.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 | $0.00055 | $0.09077 |
| Opus 5.5 | $0.00022 | $0.03631 |
| Sonnet 5.5 | $0.00011 | $0.01815 |
| Haiku 4.5 | $0.00006 | $0.00908 |
Grade A, and why
android-design-guidelines 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.
This is a copy
100% identical to android-design-guidelines — 0 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 — 1,052 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Android Platform Design Guidelines — Material Design 3
1. Material You & Theming [CRITICAL]
1.1 Dynamic Color
Enable dynamic color derived from the user's wallpaper. Dynamic color is the default on Android 12+ and should be the primary theming strategy.
// Compose: Dynamic color theme
@Composable
fun AppTheme(
darkTheme: Boolean = isSystemInDarkTheme(),
dynamicColor: Boolean = true,
content: @Composable () -> Unit
) {
val colorScheme = when {
dynamicColor && Build.VERSION.SDK_INT >= Build.VERSION_CODES.S -> {
val context = LocalContext.current
if (darkTheme) dynamicDarkColorScheme(context)
else dynamicLightColorScheme(context)
}
darkTheme -> darkColorScheme()
else -> lightColorScheme()
}
MaterialTheme(
colorScheme = colorScheme,
typography = AppTypography,
content = content
)
}
<!-- XML: Dynamic color in themes.xml -->
<style name="Theme.App" parent="Theme.Material3.DayNight.NoActionBar">
<item name="dynamicColorThemeOverlay">@style/ThemeOverlay.Material3.DynamicColors.DayNight</item>
</style>
Rules:
- R1.1: Always provide a fallback static color scheme for devices below Android 12.
- R1.2: Never hardcode color hex values in components. Always reference color roles from the theme.
- R1.3: Test with at least 3 different wallpapers to verify dynamic color harmony.
1.2 Color Roles
Material 3 defines a structured set of color roles. Use them semantically, not aesthetically.
| Role | Usage | On-Role |
|---|---|---|
primary |
Key actions, active states, FAB | onPrimary |
primaryContainer |
Less prominent primary elements | onPrimaryContainer |
secondary |
Supporting UI, filter chips | onSecondary |
secondaryContainer |
Navigation bar active indicator | onSecondaryContainer |
tertiary |
Accent, contrast, complementary | onTertiary |
tertiaryContainer |
Input fields, less prominent accents | onTertiaryContainer |
surface |
Backgrounds, cards, sheets | onSurface |
surfaceVariant |
Decorative elements, dividers | onSurfaceVariant |
error |
Error states, destructive actions | onError |
errorContainer |
Error backgrounds | onErrorContainer |
outline |
Borders, dividers | — |
outlineVariant |
Subtle borders | — |
inverseSurface |
Snackbar background | inverseOnSurface |
What ships with it
3 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.
- 1mo ago First seen · 1,052 lines · 55 tokens per session scan A 403458e7700c
android-design-guidelines is a skill published in the GitHub repository chama-x/GroundRules (5 stars, last pushed 2mo ago), licensed MIT. It adds 55 tokens to every session and 9,077 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to android-design-guidelines, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
android-compose-patterns
Use when building native Android with Jetpack Compose - stateless composables, state hoisting, ViewModel-owned state, edge-to-edge, predictive back, adaptive layout, atomic components, and Material theming over hardcoded values.
mobile-design-system-foundation
Use when the mobile repository has no theme tokens or component library yet (a new app, an "Apply design system" task, or a task that asks for one), before building any screen - writes the approved design system's generated files from getdesignsystem (files true) and builds the theme from them when there is one.
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.
mobile-ui
Use when a ticket builds or reworks UI in a React Native / Expo (or React + Capacitor) mobile app and it must feel like a real, store-credible native app — not a wrapped mobile website. Covers the native-feel bar, safe areas and edge-to-edge, gestures and back navigation, haptics, Dynamic Type and screen readers…