Meshtastic-Android/docs/en/developer/architecture.md

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title	parent	nav_order	last_updated	aliases
Architecture	Developer Guide	1	2026-05-13	layers module-architecture kmp

Architecture

The Meshtastic Android/Desktop/iOS application follows a modular Kotlin Multiplatform (KMP) architecture with clear layer boundaries.

Layer Overview

┌─────────────────────────────────────────────┐
│          androidApp / desktopApp            │  Platform entry points
├─────────────────────────────────────────────┤
│              feature/* modules               │  UI + Business Logic
├─────────────────────────────────────────────┤
│                core/* modules                │  Shared infrastructure
├─────────────────────────────────────────────┤
│           Platform (Android/JVM/iOS)         │  OS-specific bindings
└─────────────────────────────────────────────┘

Module Categories

androidApp/ — Android Application

The Android application entry point:

• Activity, Application, and Manifest definitions
• Koin DI module composition (AppKoinModule)
• Flavor-specific bindings (google/, fdroid/)
• Android-only integrations (widgets, services)

desktopApp/ — Desktop JVM Application

The Desktop (Linux/macOS/Windows) entry point:

• Compose Desktop window management
• Desktop-specific DI (DesktopKoinModule)
• Platform stubs for Android-only capabilities
• BLE (Kable), Serial, and TCP transport implementations

feature/* — Feature Modules

Each feature/ module owns a vertical slice of functionality:

Module	Responsibility
feature:intro	Onboarding/welcome flow
feature:messaging	Messages, channels, contacts, quick chat
feature:connections	Bluetooth/USB/TCP connection management
feature:map	Map display, waypoints
feature:node	Node list, node detail, metrics
feature:settings	All configuration screens
feature:firmware	Firmware update flow
feature:docs	In-app documentation browser
feature:wifi-provision	WiFi provisioning
feature:widget	Android home screen widgets

Feature modules:

• Use the meshtastic.kmp.feature convention plugin
• Depend on core modules, never on other feature modules
• Own their navigation entries and DI registrations
• Contain platform-specific implementations in androidMain/jvmMain/iosMain

core/* — Core Modules

Shared infrastructure used by all features:

Module	Responsibility
core:common	Utilities, extensions, build config
core:navigation	Routes, deep links, Navigation 3
core:ui	Shared Compose components, icons, theme
core:resources	Shared string resources
core:model	Domain models
core:data	Data layer abstractions
core:database	Room KMP database
core:datastore	DataStore preferences
core:prefs	App preferences
core:repository	Repository interfaces
core:service	Mesh service layer
core:di	DI utilities
core:network	HTTP/serial/transport
core:ble	Bluetooth LE abstractions
core:proto	Protobuf definitions
core:testing	Test utilities

KMP Source Sets

Each module uses the standard KMP source set hierarchy:

src/
├── commonMain/     ← Shared code (all platforms)
├── commonTest/     ← Shared tests
├── androidMain/    ← Android-specific
├── jvmMain/        ← Desktop JVM-specific
├── iosMain/        ← iOS-specific
└── jvmTest/        ← Desktop test host

Golden Rules:

• No android.* imports in commonMain
• Platform-specific code goes in appropriate source set
• Prefer interfaces + DI over expect/actual for complex behaviors
• Use expect/actual only for simple declarations

Dependency Injection

The project uses Koin with annotation processing:

• @Module, @Single, @Factory annotations
• @ComponentScan for automatic registration
• Feature modules export their own Feature*Module class
• App/Desktop compose all modules in their root DI configuration

Navigation

Navigation uses Navigation 3 with typed routes:

• All routes defined in core/navigation/Routes.kt
• Routes are @Serializable data classes/objects
• Deep links resolved through DeepLinkRouter
• Each feature registers its own navigation entries

See Navigation & Deep Links for details.

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