new-module-checklist

name	new-module-checklist
description	Step-by-step module creation checklist. Use when adding a new Gradle module and wiring build, DI, and architecture integration correctly.

Skill: Adding a New Module

Overview

The build system is convention-driven: naming a module correctly causes buildSrc/CorePlugin to automatically apply the right plugins, dependencies, and Room options. Follow this checklist when adding any new Gradle module.

Before creating a new module, confirm the work does not belong in an existing :android:* or :app:core helper surface. Theme/configuration, notification, deep-link, drawer, and general Android utility work often extends those modules rather than introducing a new module.

Key files to read

• buildSrc/src/main/java/co/anitrend/buildSrc/module/Modules.kt — central registry of all module paths; must be updated for every new module
• buildSrc/src/main/java/co/anitrend/buildSrc/plugins/CorePlugin.kt — the convention plugin applied to every module
• buildSrc/src/main/java/co/anitrend/buildSrc/plugins/components/ProjectDependencies.kt — determines which libraries are automatically injected based on module type
• settings.gradle.kts — where the include(":your:new:module") declaration lives

Step-by-step checklist

0. Placement decision

• If the change is a platform/helper concern, inspect :android:*, :app:core, and .agents/skills/android-platform-patterns/SKILL.md first.
• Only create a new module when an existing module cannot own the change cleanly.

1. File system

• Create the module directory following the existing layout (feature/, data/, common/, etc.).
• Add build.gradle.kts applying the CorePlugin (copy from a similar existing module).
• Add src/main/kotlin/ and src/main/AndroidManifest.xml (for Android library modules).

2. Gradle wiring

• Add include(":your:new:module") to settings.gradle.kts.
• Register the path constant in Modules.kt under the correct category (Feature, Data, Common, Android, Task, etc.).

3. Dependency injection (Koin)

• Create <module>/src/main/kotlin/.../koin/Modules.kt (see .agents/skills/koin-module-wiring/SKILL.md).
• Add the module loader to the Modules.kt file in the module's immediate parent Gradle module. If that parent module is new and must load at app startup, also add the parent loader to app/core/src/main/kotlin/co/anitrend/core/koin/Modules.kt.

4. Domain / Data wiring (if a data or feature module)

• Choose the reference pattern by shape: tag for a single query-only read, media for multiple read contracts against one entity, medialist or review for modules that both read and write, and favourite for a single mutation-only toggle.
• Define the domain repository contract in :domain; if the module performs both reads and writes, split it by operation (Detail, Paged, Save, Delete, Rate, etc.) instead of one broad interface.
• Define the abstract domain use case in :domain; do not keep repository contracts or concrete interactor implementations inside the module Types.kt.
• Implement the repository specialization in the new data module and export aliases from Types.kt.
• Create the data-layer interactor bridge in usecase/; simple modules may use XxxUseCaseImpl, while multi-operation modules may use nested XxxInteractor classes.
• If writes should be background-safe or follow existing mutation routing, add the matching :task:* worker and router plumbing instead of calling the mutation interactor directly from feature code.
• Follow the four-file entity pattern if adding persistence (see .agents/skills/room-entity-pattern/SKILL.md).

5. Validation

• Run ./gradlew :your:new:module:assembleDebug to verify plugin and dependency resolution.
• Run ./gradlew spotlessCheck to validate formatting.
• If Room is involved, confirm schema JSON is exported under data/schemas/.

Automatic dependency injection by module type

Module prefix	Auto-included libraries
:feature:*	support-arch UI/domain/data, Compose, AndroidX core, Koin, Timber
:data:*	Room + KSP, Retrofit, OkHttp, Kotlinx Serialization, Chucker (debug)
:common:*	support-arch UI, Compose (for :app:*, :feature:*, :android:*, and :common:* modules), Koin
:task:*	WorkManager, support-arch, Koin
:android:*	AndroidX core, support-arch, Koin