# Implement Feature

> Skill: Implement a Feature

- Skill: `meshtastic/implement-feature` (Agent Skill)
- Install (CLI): `npx skillmds@latest add meshtastic/implement-feature`
- Raw SKILL.md: https://api.skillmd.com/api/skills/meshtastic/implement-feature/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: meshtastic (https://skillmd.com/u/meshtastic)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/meshtastic/implement-feature

---

# Skill: Implement a Feature

## Description
A step-by-step workflow for implementing a new feature in the Meshtastic-Android codebase, ensuring KMP compatibility and proper architecture.

## Workflow

### 1. Update Dependencies & Aliases
- Check `gradle/libs.versions.toml` before adding libraries.
- Use `jetbrains-*` aliases for lifecycle/navigation/adaptive dependencies in `commonMain`.
- Use `compose-multiplatform-*` aliases for CMP dependencies.

### 2. Define the State & ViewModels
- Follow MVI/UDF patterns.
- Extend shared ViewModel logic in `feature/<name>/src/commonMain/kotlin/org/meshtastic/feature/<name>/<Name>ViewModel.kt`.
- Use `stateInWhileSubscribed` (from `core:ui`) for sharing state flows.
- Keep the ViewModel free of Android framework dependencies.

### 3. Build the UI
- Use Jetpack Compose Multiplatform (CMP).
- Define strings in `core:resources` (see the `compose-ui` skill).
- Support adaptive layouts (Large/XL breakpoints).

### 4. Wire Navigation & DI
- Define typed route objects in `core:navigation`.
- Export the navigation graph as an extension function on `EntryProviderScope<NavKey>` in `commonMain` (e.g., `fun EntryProviderScope<NavKey>.myFeatureGraph()`).
- Add the required DI bindings via Koin Annotations (`@Factory`, `@Single`, `@KoinViewModel`) in `commonMain`.
- **CRITICAL:** Ensure the module is registered in the app root graphs (`AppKoinModule.kt`, `DesktopKoinModule.kt`) and the navigation is injected into the root entry provider in the host shell.

### 5. Validate Platform Separation
- If you need a platform-specific API (like camera or specific mapping SDK), define an interface in `commonMain`, implement it in the host shell, and inject it via `CompositionLocal` or Koin.

### 6. Verify Locally
- Run the baseline checks (see `testing-ci` skill):
  ```bash
  ./gradlew spotlessApply spotlessCheck detekt assembleDebug test allTests
  ```
- Add `kmpSmokeCompile` to the command when the feature touches a KMP module (most features do) so cross-target compile failures surface before merge.
- If the feature adds a new reflection-heavy dependency, add keep rules to **both** `androidApp/proguard-rules.pro` and `desktopApp/proguard-rules.pro`, then verify release builds:
  ```bash
  ./gradlew assembleFdroidRelease :desktopApp:runRelease
  ```