android-gradle-architecture-pro

name	android-gradle-architecture-pro
description	Reviews multi-module Android Gradle builds against the Now in Android convention-plugin pattern — `build-logic/convention/` factoring, version-catalog discipline, AGP/Kotlin/Compose-compiler co-versioning, KSP over kapt. Use when reading, writing, or reviewing Gradle build files in non-trivial Android projects.
license	MIT
metadata	{"author":"AppBootstrapAI contributors","version":"1.0","grounded_in":"Android 'Now in Android' (https://github.com/android/nowinandroid), Android Developers docs for AGP 8.x"}

Review Android Gradle build configuration for adherence to modern multi-module conventions. The reference pattern is Now in Android (NiA) — Google's official reference app — which factors all repeated android { ... } and dependency declarations into convention plugins under build-logic/convention/. Report only genuine problems; don't nitpick.

Review process:

1. Inventory the build-file landscape using references/inventory.md — which files exist, what each is responsible for.
2. Check the convention-plugin factoring using references/convention-plugins.md — is repeated config extracted? Where does it live?
3. Validate version-catalog discipline using references/version-catalogs.md — no inline implementation("group:artifact:version") strings, no hardcoded versions in build.gradle.kts.
4. Validate the multi-module graph using references/multi-module-graph.md — :app + :feature:* + :data:* + :core:* shape, dependency direction.
5. Check AGP / Kotlin / Compose-compiler co-versioning using references/agp-versioning.md.
6. Verify KSP is used over kapt for all supported annotation processors using references/ksp-over-kapt.md.

If doing a partial review, load only the relevant reference files.

Core Instructions

• Now in Android is the reference. When in doubt, check what NiA does. Their convention plugins under build-logic/convention/ are the canonical examples.
• Convention plugins are non-negotiable past 3 modules. Once you have a :feature:home, :feature:settings, :feature:profile, the third repeated android { compileSdk = 34; defaultConfig { minSdk = 26; ... } } block is a smell. Factor.
• Version catalogs are the single source of truth. Every version literal in a build.gradle.kts is a regression — there's always a [versions] entry it should reference.
• AGP version is grounded in AGP 8.x for this skill. AGP 9 specifics are unverified; if the project uses AGP 9, defer to the actual release notes rather than this skill's guidance.
• Don't suggest applying convention plugins where they're not warranted. A single-module app doesn't need build-logic/convention/. Convention plugins are a multi-module concern.
• Don't introduce buildSrc/ for new code. The build-logic/ composite-build pattern superseded buildSrc because the latter invalidates Gradle's cache more aggressively. NiA uses build-logic; new projects should too.

Output Format

Organize findings by file. For each issue:

1. State the file and relevant line(s).
2. Name the rule being violated.
3. Show a brief before/after.

Skip files with no issues. End with a prioritized summary.

Example output:

feature/home/build.gradle.kts

Line 12: Repeated android { } block — extract to a convention plugin.

// Before
android {
    namespace = "com.kozinga.feature.home"
    compileSdk = 34
    defaultConfig { minSdk = 26 }
    buildFeatures { compose = true }
}

// After
plugins {
    alias(libs.plugins.kozinga.android.feature)
    alias(libs.plugins.kozinga.android.library.compose)
}

android {
    namespace = "com.kozinga.feature.home"
}

Line 28: Inline dependency string — use the version catalog.

// Before
implementation("androidx.core:core-ktx:1.15.0")

// After
implementation(libs.androidx.core.ktx)

build-logic/convention/build.gradle.kts (missing)

No build-logic/ convention-plugin module — three feature modules repeat the same android {} block. Create build-logic/convention/ and factor AndroidFeatureConventionPlugin.

Summary

1. Architecture (high): No convention plugins; three :feature:* modules duplicate android {} configuration.
2. Catalog discipline (medium): Four inline dependency strings across feature/home/build.gradle.kts and feature/settings/build.gradle.kts — migrate to libs.versions.toml.
3. kapt → KSP (low): kapt for Hilt — switch to ksp(libs.hilt.compiler) for faster builds.

End of example.

References

• references/inventory.md — what every Android Gradle file is responsible for (settings.gradle.kts, root build.gradle.kts, module build.gradle.kts, libs.versions.toml, gradle.properties, build-logic/).
• references/convention-plugins.md — how to author a convention plugin in build-logic/convention/, the NiA factoring (AndroidApplicationConventionPlugin, AndroidLibraryConventionPlugin, AndroidComposeConventionPlugin, AndroidFeatureConventionPlugin, AndroidHiltConventionPlugin, AndroidApplicationJacocoConventionPlugin).
• references/version-catalogs.md — libs.versions.toml depth, [bundles], plugin entries, migration patterns from inline strings.
• references/multi-module-graph.md — :app + :feature:* + :data:* + :core:* shape, dependency direction, how features avoid depending on each other.
• references/agp-versioning.md — AGP/Kotlin/Compose-compiler version matrix (AGP 8.x), the Kotlin 2.0+ Compose plugin model, common upgrade pitfalls.
• references/ksp-over-kapt.md — KSP-first stance for Hilt / Room / Moshi / Glide, what migration looks like, what still requires kapt.