Jetpack Compose and Multiplatform Expert

What it does

When your agent uses it

• Fixing a slow or over-recomposing Compose screen
• Building a Compose screen from a Figma design or screenshot
• Sharing UI code between Android and iOS with Compose Multiplatform
• Working out why a LaunchedEffect or remember call misbehaves

Example prompts

• “My Compose screen janks when scrolling a LazyColumn. Find the recomposition problem.”
• “Implement this Figma login screen in Compose using our MaterialTheme tokens.”
• “Move this screen into commonMain and show me what needs expect/actual.”

Workflow steps

5 steps, taken from the step headings in SKILL.md.

1. 1Understand the request
2. 2Analyze the design (if visual reference provided)
3. 3Consult the right reference
4. 4Apply and verify
5. 5Cite the source

What it can do on your machine

Read from SKILL.md and the folder at commit 0f9af5a. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • gh

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • raw.githubusercontent.com
  • android.googlesource.com

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Jetpack Compose and Multiplatform Expert loads about 2.6k tokens when it runs, and up to ~41k if it reads all its reference files. Until then it costs about 238 tokens; SKILL.md has 737 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~238

When it runs · the whole SKILL.md, loaded when a task matches

~2.6k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~41k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from rcosteira79/android-skills at commit 0f9af5a, republished under its MIT licence (© rcosteira79). 737 words, ~2,555 tokens.

name

compose

description

Compose and Compose Multiplatform expert for UI development across Android, Desktop, iOS, and Web. Covers state management, composition, animations, navigation, performance, design-to-code workflows, and production crash patterns, backed by source analysis from androidx/androidx and JetBrains/compose-multiplatform-core. Use whenever the user mentions Compose, @Composable, remember, LaunchedEffect, Scaffold, NavHost, NavDisplay, MaterialTheme, LazyColumn, Modifier, recomposition, Compose Multiplatform/CMP, commonMain, expect/actual, ComposeUIViewController, UIKitView, ComposeViewport, Res.drawable/Res.string, or any Compose API. Also trigger on phrases like "design to compose", "build this UI", "implement this design", or any modern Kotlin UI question — including casual mentions like "my compose screen is slow". Plus focus topics: FocusRequester, focusProperties, onPreviewKeyEvent, D-pad, TV remote, ChromeOS, androidx.tv.material3.

// See: compose/runtime/runtime/src/commonMain/kotlin/androidx/compose/runtime/Composer.kt

lookup_class(className: "LazyListState")
lookup_method(className: "Composer", methodName: "startRestartGroup")
search_in_source(query: "fun rememberLazyListState")
list_class_members(className: "Modifier")
get_class_hierarchy(className: "LazyListState")
find_references(className: "SnapshotState", methodName: "value")

androidx/androidx (branch: androidx-main)
├── compose/runtime/runtime/src/commonMain/kotlin/androidx/compose/runtime/
├── compose/ui/ui/src/androidMain/kotlin/androidx/compose/ui/platform/
├── compose/ui/ui/src/commonMain/kotlin/androidx/compose/ui/
├── compose/foundation/foundation/src/commonMain/kotlin/androidx/compose/foundation/
├── compose/material3/material3/src/commonMain/kotlin/androidx/compose/material3/
└── compose/navigation/navigation-compose/src/commonMain/kotlin/androidx/navigation/compose/

compose-multiplatform-core (branch: jb-main)
├── compose/ui/ui/src/desktopMain/kotlin/androidx/compose/ui/window/
├── compose/ui/ui/src/iosMain/kotlin/androidx/compose/ui/window/
├── compose/ui/ui/src/webMain/kotlin/androidx/compose/ui/window/
├── compose/ui/ui/src/skikoMain/kotlin/androidx/compose/ui/
└── compose/foundation/foundation/src/skikoMain/kotlin/androidx/compose/foundation/

compose-multiplatform (resources library)
└── components/resources/library/src/commonMain/

android docs search "LazyColumn performance"              # ranked kb:// URLs + summaries
android docs fetch kb://android/develop/ui/compose/lists  # full content of a result

© rcosteira79, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 21 other files (references) in plugins/android-skills/skills/compose of rcosteira79/android-skills.

• SKILL.md
• references/accessibility.md
• references/animation-advanced.md
• references/animation-recipes.md
• references/animation.md
• references/composition-locals.md
• references/deprecated-patterns.md
• references/design-to-compose.md
• references/focus-navigation.md
• references/lists-scrolling.md
• references/modifiers.md
• references/multiplatform.md
• references/navigation.md
• references/performance.md
• references/platform-specifics.md
• references/production-crash-playbook.md
• references/screen-structure.md
• references/side-effects.md
• references/state-management.md
• references/styles-experimental.md
• … and 2 more

Open the folder on GitHubat commit 0f9af5a