kta-module

name

kta-module

description

Bootstrap a new Gradle module in any Kotlin Android project. Walks the user through choosing one of three module types — library module (`com.android.library`), feature module (regular Android library that hosts a feature/UI, install-time only), or dynamic feature module (`com.android.dynamic-feature`, on-demand/conditional/instant delivery). Use whenever the user wants to add a module, modularize code, extract a util/data/ui layer, create a new feature, set up Play Feature Delivery, or asks "should this be a library or feature module?". Discovers the project's existing conventions (plugin aliases, namespaces, sibling modules, version catalog) instead of hardcoding any. Pushes back on bad combos (e.g. utility code in a dynamic feature). Stops at scaffolding; app-level wiring is out of scope.

Android Module Bootstrap

Create a new Gradle module in any Kotlin Android project. Three flavors are supported, and the user MUST consciously pick one. This skill enforces an intake conversation and discovers project conventions before scaffolding — no hardcoded plugin aliases, namespaces, or DI/nav patterns.

Scope

• IN: Module type selection, Gradle skeleton, manifest, base package layout, settings.gradle.kts include, dynamicFeatures registration on the application module (DFM only).
• OUT: App-level wiring (registering DI graphs, navigation graphs, route classes, feature registries) — those are project-specific concerns left to the consumer or a follow-up step.

Module Types (Decision Matrix)

Type	Plugin	Use When	Anti-pattern
Library	com.android.library	Reusable utilities, design tokens, repositories, use cases, shared UI atoms	Owns a navigation route into an app shell
Feature Module	com.android.library (+ Compose/Hilt/Koin as project requires)	Feature always shipped, install-time only, no on-demand needed	Pure utility with no feature surface
Dynamic Feature	com.android.dynamic-feature	Independently deliverable feature: on-demand, conditional, instant-app, or large feature you may want to defer install	Tiny shared util, single composable, code consumed by other modules (creates cycles)

Read references/module-types-decision.md for full pros/cons, sizing heuristics, and recovery paths.

Step 0 — Discover Project Conventions (DO THIS FIRST)

Before any question or scaffold, read the project to learn its conventions. Do not guess; do not hardcode this skill's prior assumptions.

1. Plugin aliases / version catalog: Read gradle/libs.versions.toml (if present). Look for plugin aliases mapping to com.android.library, com.android.dynamic-feature, com.android.application, org.jetbrains.kotlin.android, Compose, KSP, Hilt, etc. Also check for project-internal convention plugins (e.g. anything under build-logic/ or pre-compiled script plugins). Use whatever the project already uses.
2. Sibling modules: List existing modules from settings.gradle.kts and read 1–2 representative build.gradle.kts files (one library, one feature/dfm if present). Match their plugin block, dependency style, and android { } config (namespace pattern, buildFeatures, testing libs).
3. Application module: Find the com.android.application module. Note its package, dynamicFeatures = setOf(...) block (if any), and how it depends on existing libraries/features.
4. Namespace pattern: Derive the convention from sibling modules (e.g. com.acme.feature.X, com.acme.lib.X). Don't invent a new one.
5. DI / Nav / Compose: Check whether siblings use Hilt, Koin, Dagger, Compose Navigation, etc. The new module should match.
6. JVM / SDK: Detect compileSdk, minSdk, targetSdk, JVM target, Kotlin version from existing modules or root config. If a convention plugin sets these, just apply the convention plugin and don't redeclare.

If libs.versions.toml is missing, fall back to vanilla AGP plugin IDs (com.android.library, com.android.dynamic-feature, org.jetbrains.kotlin.android, org.jetbrains.kotlin.plugin.compose).

State your findings to the user in 3–5 lines so they can correct you before you scaffold.

Step 1 — Mandatory Intake

Ask the user — sequentially, plain text, not all at once:

1. What is the module's purpose? (One sentence: "audio playback util", "settings feature", "AI assistant feature deferred install"…)
2. Who consumes it? (App only / multiple features / shared infra)
3. Does it own a user-facing screen with a nav route? (yes / no)
4. Delivery requirement: install-time always, or on-demand / conditional / instant?
5. Rough size: <500 LOC / 500–5k / 5k+

Map answers to a recommendation:

• Purpose is "util / shared / tokens / repo / use case" + no route → Library
• Owns a route + always shipped → Feature Module (or Dynamic Feature if the codebase clearly prefers DFMs — detect this from sibling modules)
• Owns a route + on-demand/conditional/instant OR very large → Dynamic Feature
• If dynamicFeatures = setOf(...) is empty in the application module and there are no existing DFMs, default to Feature Module for new features. If the project already uses DFMs, default to Dynamic Feature to match precedent.

Step 2 — Recommend + Confirm

State the recommended type with one-sentence justification and cite the convention you observed. Then list pros/cons of all three (pull from references/module-types-decision.md). End with: "Pick library / feature / dynamic-feature, or tell me your reasoning to override."

Pushback Rules (be direct, not sycophantic)

If the user picks a type that contradicts their answers, push back BEFORE scaffolding. Do not silently comply.

• User says "util library for string helpers" + picks dynamic-feature → Warn: "DFMs are for independently deliverable user-facing features. A util has no route, no delivery story, and forcing it into a DFM creates a cyclic application-module dependency for nothing. Recommend Library. Override?"
• User says "code consumed by other library modules" + picks dynamic-feature → Hard warn: "DFMs reverse-depend on the application module; other libraries cannot depend on a DFM (cycle). This will not compile. Must be a Library."
• User says "instant app / on-demand / conditional" + picks library or feature → Warn: "Plain library and feature modules always ship in the base APK. You lose the delivery flag you asked for. Must be Dynamic Feature for on-demand."
• User picks a type that contradicts the codebase's clear convention → Note the divergence, ask whether it's intentional. Don't silently break consistency.

Wait for explicit "go" before Step 3.

Step 3 — Scaffold

Once type is locked, follow the matching reference:

• Library → references/library-module-structure.md
• Feature Module → references/feature-module-structure.md
• Dynamic Feature → references/dfm-structure.md (+ references/delivery-options.md if on-demand/conditional)

Then update root files:

1. settings.gradle.kts — add include(":<path>"). Mirror the path style observed in the project (flat :my-lib vs grouped :feature:my-feature).
2. DFM only: the application module's build.gradle.kts → add to dynamicFeatures += setOf(...) (or dynamicFeatures = setOf(...) depending on existing style).
3. DFM only: add res/values/strings.xml with the dist:title resource referenced by the manifest.

When writing files, substitute the project's actual conventions:

• Plugin aliases the project already uses (convention plugins, version-catalog aliases, or raw plugin IDs)
• Namespace matching the project's pattern
• DI / nav / Compose deps mirroring the sibling module you sampled
• JVM target / SDK levels from the project's existing config (or omit if a convention plugin handles them)

Reference templates show vanilla AGP defaults — adapt to what you discovered in Step 0.

Step 4 — Verify

• Run ./gradlew :<module-path>:compileDebugKotlin to confirm the skeleton compiles.
• If the project requires google-services.json or other secrets to assemble, prefer compileDebugKotlin over assembleDebug for verification.
• Report: module path, plugin used, what's wired, what app-level steps the user must do next (e.g. register DI/nav, populate routes — these are project-specific).

References

• references/module-types-decision.md — Full decision matrix, sizing, anti-patterns, recovery paths
• references/library-module-structure.md — Plain library template (vanilla AGP)
• references/feature-module-structure.md — Feature as regular library template
• references/dfm-structure.md — Dynamic feature template
• references/delivery-options.md — install-time / on-demand / conditional / fusing