Jetpack Compose audit + coding-agent skills for Claude Code, Codex, Cursor, and Anthropic-style skill loaders.
Version 4.1.2 · released 2026-06-14 — Repo hygiene patch: the 4.1.0 eval scenarios are now a machine-readable evals.json inside the audit skill instead of prose in docs/, the full release history moved to CHANGELOG.md, and the launch-tweet drafts were dropped from docs/. No skill-behavior changes. Both skills ship as 4.1.2.
Find out where your Compose app is burning frames, by how much, and what to change to win them back — measured against real compiler data, not vibes.
A strict, evidence-based audit for Android Jetpack Compose repositories. Point it at a repo, let it run the build once, and get back a 0-100 score, a 0-10 score per category, an actionable top-three fix list, and a full Markdown report with every deduction cited against an official developer.android.com page.
Built for Claude Code, Codex, Cursor, and any agent that loads the Anthropic skill format.
Authored and cross-reviewed with every frontier model — Claude Opus 4.8, GPT-5.5, and Gemini 3.5 Flash — each used to pressure-test the rubric, prompts, and references so the audit holds up regardless of which model ends up running it.
Repo hygiene — evals as data, changelog split out, launch cruft removed.
- Evals are machine-readable now. The 4.1.0 acceptance scenarios moved from prose in
docs/evals-4.1.0.mdtoskills/jetpack-compose-audit/evals/evals.json—skill_name+ ten{prompt, expected_output, expectations}cases, the canonical eval layout (anevals/directory inside the skill). - Changelog split out. Full release history now lives in
CHANGELOG.md; this README keeps only the latest release here. - Dropped launch cruft. Removed the launch-tweet drafts (
docs/tweet-*.md) from the repo; release notes stay indocs/. - No behavior change. Skill guidance, audit scoring, and search leads are identical to
4.1.1. - Versions.
compose-agent→4.1.2.jetpack-compose-audit→4.1.2.
For the full release history, see CHANGELOG.md.
Run the skill on a Compose repo and you walk away with:
COMPOSE-AUDIT-REPORT.mdwritten at the target root — per-category scoring, evidence file paths, line numbers, and prioritized fixes.- A chat summary that mirrors the report's top three fixes — same file paths, same doc links, same predicted impact. Act on the chat alone if you're short on time.
- Measured stability numbers from the Compose Compiler — module-wide
skippable%, named-onlyskippable%, the unstable-class list, and the per-module Strong Skipping state inferred from compiler version plus explicit flags. - Android Launch UX findings for static Android 12+ splash icons that can render blurry when a
drawable-v31animated-vector wrapper is missing. - A score you can defend. Every deduction carries an official Android Developers URL. No "trust me" findings.
Four categories, weighted for an app repo. Each scored 0-10; overall on 0-100.
| Category | Weight | What it covers |
|---|---|---|
| Performance | 35% | Work in composition, lazy-list keys, state-read timing, stability, Strong Skipping, backwards writes, animation phase correctness, baseline profiles |
| State management | 25% | Hoisting, single source of truth, rememberSaveable, lifecycle-aware collection, observable collections, ViewModel placement, type-safe navigation |
| Side effects | 20% | Effect API choice, keys, stale captures, cleanup, composition-time work, animation driving via LaunchedEffect |
| Composable API quality | 20% | Modifier conventions, parameter order, slot APIs, CompositionLocal usage, Modifier.Node, animationSpec exposure, @Preview coverage, hardcoded strings / magic numbers |
Score bands: 0-3 fail · 4-6 needs work · 7-8 solid · 9-10 excellent.
Adjacent, non-scored coverage includes UI tests/previews, focus/keyboard, KMP/CMP, and Android Launch UX resources. Those findings do not change the 0-100 score, but they can still show up in Critical Findings and Prioritized Fixes when they are concrete and user-visible.
Concrete smells the rubric targets, with realistic wins:
| Smell | Expected gain after fix |
|---|---|
Unstable or repeatedly recreated params (List, domain models, ArrayList-backed state, listOf(...), fresh UI models) |
On older compiler tracks, can lift named-only skippable% and the Performance ceiling. Under Strong Skipping, usually removes instance-recreation churn or expensive equals() work that was still forcing re-runs despite high skippability. |
Lazy-list items(...) without stable key = |
Fewer reallocated compositions on reorder, smoother scroll, fewer IllegalArgumentException: Key already used crashes |
| Rapidly-changing state read high in the tree | Recompositions collapse from "per frame, whole screen" to "per frame, single modifier" |
Animated .value piped into Modifier.offset(x.dp) / Modifier.alpha(a) |
Moving to Modifier.graphicsLayer { ... } / Modifier.offset { ... } defers per-frame reads to layout/draw — same animation, fraction of the recomposition cost |
Animatable(...) created in a composable body without remember |
Animation no longer resets on every recomposition; velocity and target survive |
rememberCoroutineScope().launch { animatable.animateTo(...) } for target-driven animation |
Replace with LaunchedEffect(target) — restart semantics follow the target automatically, while rememberCoroutineScope() stays available for event-driven animation |
rememberInfiniteTransition hosted on something that stays composed offscreen |
Scoping it to visible content avoids needless offscreen animation work and lets it stop when the host actually leaves composition |
collectAsState() on Android UI flows |
Swap to collectAsStateWithLifecycle() — no collection when UI is paused |
mutableStateOf<Int> / <Long> / <Float> in hot paths |
Remove autoboxing, fewer allocations |
| Hardcoded strings and magic numbers in reusable components | i18n + dark-mode + accessibility ready; testable |
rememberSaveable inside a LazyListScope item factory |
No more TransactionTooLargeException when the list grows |
Scaffold { innerPadding -> ... } content that ignores innerPadding |
Content stops drawing behind the TopAppBar / system bars |
Static Android 12+ splash icon in windowSplashScreenAnimatedIcon |
Wrap with a drawable-v31 animated-vector so the launch icon stays crisp instead of being rasterized small and scaled up |
The report lists every occurrence with file path and line number, not just the category.
Measured, not inferred. The skill ships scripts/compose-reports.init.gradle and injects it into your Gradle build via --init-script — no edits to your build.gradle. Every run parses real *-classes.txt / *-composables.txt / *-module.json output.
Mandatory ceilings. A Performance score cannot exceed the cap set by the matching ceiling table. On older compiler tracks the cap is driven by skippable% plus unstable-param count; under Strong Skipping it is driven by named-only skippable%, instance-recreation churn, and equals() quality on unstable params. The ceiling math appears in the report so the score is auditable.
Every deduction cites an official source. Each finding carries a References: line pointing at developer.android.com or the AndroidX component API guidelines. Audits that can't be defended with a URL don't ship.
Actionable chat summary. The chat output mirrors the report's Prioritized Fixes — same file paths, same doc links, same predicted impact ("stops rebuilding FeedItemUiModel, removes the Strong-Skipping cap from 8 → no cap").
Install both skills:
npx --yes skills add hamen/compose_skill --skill '*' -yOr install one skill:
npx --yes skills add hamen/compose_skill --skill jetpack-compose-audit -y
npx --yes skills add hamen/compose_skill --skill compose-agent -yThis is the preferred path for Codex, Claude Code, Cursor, and multi-agent setups because the repo now follows the direct skills/<name>/SKILL.md layout.
Direct plugin install still works if you prefer Claude Code's plugin flow:
/plugin add hamen/compose_skill --subdir skills/jetpack-compose-audit
Claude Code reads skills/jetpack-compose-audit/.claude-plugin/plugin.json and registers skills/jetpack-compose-audit/SKILL.md. For compose-agent, use:
/plugin add hamen/compose_skill --subdir skills/compose-agent
If you installed an older release with --subdir compose-agent, --subdir jetpack-compose-audit, or the nested skills/<plugin>/skills/<name> manual symlink, /plugin update will keep pointing at the old path. Remove that old install once and reinstall with the commands above.
Use this when you want git pull in this directory to update a local checkout in place:
mkdir -p ~/.claude/skills
mkdir -p ~/.codex/skills
mkdir -p ~/.cursor/skills
ln -s "$(pwd)/skills/jetpack-compose-audit" ~/.claude/skills/jetpack-compose-audit
ln -s "$(pwd)/skills/jetpack-compose-audit" ~/.codex/skills/jetpack-compose-audit
ln -s "$(pwd)/skills/jetpack-compose-audit" ~/.cursor/skills/jetpack-compose-audit
ln -s "$(pwd)/skills/compose-agent" ~/.claude/skills/compose-agent
ln -s "$(pwd)/skills/compose-agent" ~/.codex/skills/compose-agent
ln -s "$(pwd)/skills/compose-agent" ~/.cursor/skills/compose-agentFrom the agent prompt:
/jetpack-compose-audit [repo path or module path]
Or in natural language:
Audit this Compose repo.
Score the :app module for Compose quality.
Run a Compose performance review on core/ui.
The compiler-report build runs automatically and typically takes 1-5 minutes. If the build fails (no wrapper, compile error, timeout) the skill falls back to source-inferred findings, caps Performance at 7, and flags reduced confidence — all stated explicitly in the report.
Overall: 73/100
Performance: 8/10 capped by the SSM-on table: instance-recreation churn in feed params (qualitative 9)
State: 6/10 collectAsState without lifecycle, duplicate VM reads
Side effects: 7/10 LaunchedEffect key too broad at HomeScreen.kt:240
API quality: 8/10 BoxCard / SearchBar follow conventions
Compiler:
Strong Skipping: on (default)
ceiling table: SSM-on
module-wide skippable% = 186/269 = 69.14%
named-only skippable% = 121/122 = 99.18%
ceiling metric: named-only `skippable%` (module-wide metric anchored by zero-arg lambdas)
deferredUnstableClasses: 59
binding cap: 8 (fresh `FeedItemUiModel(...)` + `listOf(...)` rebuilt in `HomeFeedScreen`)
Top 3 fixes
1. collectAsState -> collectAsStateWithLifecycle across 6 call sites
feature/home/HomeScreen.kt:37, MainActivity.kt:213, ...
Doc: developer.android.com/.../side-effects
Impact: fewer redundant collections, lifecycle-correct
2. Stop rebuilding `FeedItemUiModel(...)` and `listOf(...)` inside `HomeFeedScreen`
Evidence: app/build/compose_audit/app_release-classes.txt, feature/home/HomeFeedScreen.kt:88-132
Doc: developer.android.com/.../stability
Impact: removes forced re-runs under Strong Skipping, likely clears the Performance cap from 8 -> no cap
3. Narrow LaunchedEffect(homeScreenState) at HomeScreen.kt:240-254
Doc: developer.android.com/.../side-effects
Impact: fewer redundant ensureAuthenticated() calls
In scope. Jetpack Compose on Android, Kotlin 2.0.20+ / Compose Compiler 1.5.4+ (Strong Skipping default).
Also in normal audit coverage: Android splash-screen launch resources, specifically windowSplashScreenAnimatedIcon and drawable-v31 animated-vector overrides for the Android 12+ static-icon blur workaround. This is reported as Android Launch UX, not as a scored Compose category.
Out of scope — the skill will call these out as a note rather than silently produce thin coverage:
- Material 3 compliance, theming, color/typography — defer to the
material-3skill. - Accessibility scoring (semantics, touch targets) — flagged as notes, not scored.
- UI test coverage and Compose test-rule patterns — noted as adjacent coverage, not scored.
- Compose Multiplatform (
expect/actual, target-specific code paths) — noted as adjacent coverage, not scored. - Wear OS / TV / Auto / Glance surfaces — focus/keyboard risks are noted as adjacent coverage; full platform review remains out of scope.
- Build performance (incremental compilation, KSP/KAPT choice).
skills/
jetpack-compose-audit/
.claude-plugin/plugin.json Claude Code plugin manifest
.cursor-plugin/plugin.json Cursor plugin manifest
SKILL.md main audit skill (process, principles, output)
scripts/
compose-reports.init.gradle Gradle init script injected via --init-script
references/
scoring.md rubric with measured ceilings and inline citations
search-playbook.md grep patterns, regex, read-the-file heuristics
canonical-sources.md every URL the rubric cites
report-template.md required structure for COMPOSE-AUDIT-REPORT.md
diagnostics.md manual-mode fallback snippets
compose-agent/ sibling skill — see § Sibling skill below
A sibling skill, skills/compose-agent/, ships in the same repo — see § Sibling skill for its own layout and usage.
- Strict but evidence-based. Every deduction has a file:line and an official-doc URL.
- Measured beats inferred. Compiler reports are generated automatically; source-inferred stability is a fallback, not the default.
- Written for action. The report's
Prioritized Fixessection and the chat summary mirror each other, so the developer can act on the chat alone. - Narrow scope on purpose. The skill does not score design, accessibility, or build performance in v1. It says so rather than pretending otherwise.
This repo ships a second skill alongside the audit: compose-agent/. Where the audit reviews an existing repo end-to-end and produces a score, compose-agent works at file and feature scope while you are reading, writing, or modifying Compose.
- Responds to: "is this right?", "rewrite this the modern way", "check this file for deprecated API", "find state hoisting mistakes in this feature".
- Built for: android/skills#27 — the Android equivalent of
swiftui-agent-skill. The philosophy is the same: target the mistakes LLMs actually make in Compose, not repeat basics the model already knows. - Shape: short
SKILL.mdthat routes to focused per-topic reference markdowns. You only pay the token cost for the areas your current task touches.
Use the same direct skills flow as the audit skill.
Recommended:
npx --yes skills add hamen/compose_skill --skill compose-agent -yClaude Code:
/plugin add hamen/compose_skill --subdir skills/compose-agent
Cursor: import the repo as a plugin and pick compose-agent in the subdirectory selector.
Manual: symlink skills/compose-agent/ into your skills directory (~/.claude/skills/compose-agent, ~/.cursor/skills/compose-agent, etc.).
Both skills can live side by side — they do not share state and do not interfere.
compose-agent runs in review mode or authoring mode. You do not choose; the skill picks based on your request.
Review mode — you hand it code that already exists. It produces a file-by-file report with before/after snippets and links to the official doc page behind each rule. Triggered by prompts like:
Use compose-agent to review feature/profile/.
Check ProfileScreen.kt with compose-agent.
compose-agent: find deprecated API in this module.
Authoring mode — the skill is loaded and you ask the assistant to write Compose. Before returning code, the assistant silently runs the core checks against the rules in the skill:
- Does the composable take
modifier: Modifier = Modifier? - Is state hoisted, or is there a clear reason to own it here?
- If it renders a list, does it use a stable
key =? - If it launches work, is that work in a
LaunchedEffect,produceState, or the ViewModel — not in the composition body? - If it collects a
Flow, is itcollectAsStateWithLifecycle()? - Is the parameter order data →
modifier→ other → content slot last? - If it animates, is the API declarative first, remembered where needed, lifecycle-aware, and phase-correct?
Any "no" without a reason → fixed before the code comes back. No extra prompt needed — loading the skill is enough.
The reference files are deliberately loadable in isolation. Scoping a review to one area pulls only that reference into context instead of the full skill.
| You want… | Say |
|---|---|
state correctness (hoisting, remember, saveable, ViewModel) |
compose-agent focus on state |
side-effect choice (LaunchedEffect, DisposableEffect, produceState) |
compose-agent focus on effects |
| recomposition cost + Strong Skipping | compose-agent focus on performance |
| modifier hygiene | compose-agent focus on modifiers |
| Navigation 3 adoption or Nav2.8 type-safety | compose-agent focus on navigation |
Flow collection + lifecycle + coroutine scopes |
compose-agent focus on concurrency |
Flow operator selection + StateFlow/SharedFlow shape |
compose-agent focus on flows |
| reusable composable API shape | compose-agent focus on component-api |
| Compose UI tests, screenshot tests, semantics, previews | compose-agent focus on testing |
| focus, keyboard, D-pad, TV/desktop navigation | compose-agent focus on focus |
KMP/CMP source sets, expect/actual, platform interop |
compose-agent focus on kmp |
| animation API choice, lifecycle, labels, phase-correct reads | compose-agent focus on animation |
| deprecated / soft-deprecated APIs and Android launch resources | compose-agent focus on api |
| idiomatic Kotlin / Android style | compose-agent focus on kotlin |
- File-by-file findings. File + line, rule name, minimal before/after, link to
developer.android.comor the AndroidX guidelines. - Prioritized summary of up to three items, highest impact first. Act on the chat alone if you are short on time.
- No nitpicks. Clean files are not listed.
An example output block is in compose-agent/SKILL.md under "Example Output".
Use compose-agent… |
Use jetpack-compose-audit… |
|---|---|
| while writing or editing a file | for a snapshot of the whole repo |
| for doc-linked fixes on a specific concern | for a 0–100 score across four categories |
| to make the assistant's output be correct Compose | to produce a COMPOSE-AUDIT-REPORT.md with measured evidence |
| day to day, at file / feature scope | once per release or before a review |
Overlap is fine. Audit on the release candidate, compose-agent on every feature branch.
skills/compose-agent/
.claude-plugin/plugin.json Claude Code plugin manifest
.cursor-plugin/plugin.json Cursor plugin manifest
SKILL.md short router — loads references on demand
references/
api.md deprecated + soft-deprecated APIs → modern replacements
state.md hoisting, remember, rememberSaveable, ViewModel boundary
effects.md LaunchedEffect / DisposableEffect / produceState / snapshotFlow
performance.md Strong Skipping, lambda modifiers, lazy keys, typed state
modifiers.md order, lambda form, Modifier.Node vs composed { }
navigation.md Navigation 3 + Nav2.8 type-safe destinations
concurrency.md Flow collection + lifecycle, viewModelScope, dispatchers
flows.md StateFlow / SharedFlow / cold Flow, stateIn, shareIn, flatMap variants, error handling, backpressure
component-api.md parameter order, slots, naming, state hoisting shape
testing.md UI tests, semantics assertions, screenshot tests, deterministic fakes, previews
focus.md FocusRequester, keyboard / D-pad input, focus restoration, focus tests
kmp.md KMP/CMP boundaries, expect/actual, interfaces, platform leaf composables
animation.md animation API choice, lifecycle, labels, deferred animated reads
kotlin.md Kotlin conventions + Android Kotlin style the LLM misses
MIT.