Mobile Architecture

savitri-mobile is a Flutter application for iOS and Android providing wallet management, node monitoring, governance participation, and an integrated narrative game.

Technology Stack

Layer	Technology
Framework	Flutter 3.16+, Dart 3.0+
State (DI)	Riverpod
State (events)	BLoC / Cubit
Storage	SQLite (sqflite), FlutterSecureStorage, SharedPreferences
Crypto	Rust FFI via flutter_rust_bridge
Networking	HTTP, WebSocket
Auth	Local auth (biometric), FlutterSecureStorage

Architecture Pattern

Clean Architecture with three layers:

presentation/     (screens, widgets, blocs)
    │
domain/           (entities, repositories, use cases)
    │
data/             (datasources, models, repository implementations)

676 Dart files across the application.

Main Navigation Hub

The app uses a hub-and-spoke navigation pattern:

Index	Screen	Description
0	WalletSubHub	Wallet management, balances, transfers
1	DashboardSubHub	Network overview, metrics
2	NodeSubHub	Node health monitoring (NHS score)
3	GameGateScreen	Narrative game (landscape mode)
4	NewsSubHub	Network news and updates
5	BuySaviScreen	Token purchase
6	FaucetScreen	Testnet faucet claims
7	CommunityScreen	Community features

Wallet

Key Derivation

• BIP-39: Mnemonic phrase generation (12/24 words)
• BIP-44: Derivation path m/44'/1337'/0'/0/0
• Ed25519: Key generation via Rust FFI for performance

Security

• Private keys stored in FlutterSecureStorage (Keychain on iOS, EncryptedSharedPreferences on Android)
• Biometric authentication for sensitive operations
• WalletConnect v2 for dApp connections

Database

SQLite Schema

• Database: savitri_mobile.db
• Version: 15 (15 migration steps)
• Encryption: Column-level AES-256-GCM via DbEncryption singleton
• Pattern: Singleton DatabaseHelper.instance

Platform Support

• Native: ApplicationDocumentsDirectory for DB path
• Web: Not supported (throws UnsupportedError)

Node Monitoring

The app monitors connected nodes via JSON-RPC:

• NHS Score (Node Health Score): Composite metric displayed in dashboard
• Block production: Real-time block height and finalization status
• Peer count: Connected peer monitoring
• PoU score: Validator consensus participation score

Narrative Game

A narrative game integrated into the app:

• 10 chapters with multiple levels per chapter
• Game engine: Custom Dart engine with BLoC state management
• Screens: 50+ game screen types (cinematic dialog, code review, decision tree, etc.)
• Widget library: Custom widgets (terminal, archive timeline, balance sheet, etc.)
• Assets: Video content, JSON game data per chapter
• Landscape mode: Game runs in landscape orientation

Game Systems

System	Description
game_engine	Core game loop
narrative_state	Story progression
scene_renderer	Screen rendering
badge_catalog	Achievement system
anomaly_tracker	Anomaly detection minigame
archive_system	In-game document archive
balance_tracker	In-game economy
photo_system	Photo collection
witness_mode	Observation mode
tips_catalog	Hint system

IoT Integration

The app includes IoT sensor management:

• Device registration and monitoring
• Sensor data visualization
• IoT energy service integration
• Background data collection via workmanager

Rust FFI Bridge

Performance-critical crypto operations use Rust via flutter_rust_bridge:

// Dart side
final signature = await rustBridge.signMessage(privateKey, message);
final isValid = await rustBridge.verifySignature(publicKey, message, signature);

Operations delegated to Rust:

• Ed25519 key generation
• BIP-39/44 key derivation
• Transaction signing
• Hash computation

Anti-Cheat System

The TAP game includes anti-cheat measures:

• Pattern analysis: Detects automated tapping
• Trust scoring: Per-user trust score based on behavior
• AURA formula: Anti-cheat scoring algorithm

Localization

Supported languages (ARB files):

Language	File
English	app_en.arb
Italian	app_it.arb
Spanish	app_es.arb
French	app_fr.arb
Hindi	app_hi.arb
Russian	app_ru.arb
Chinese	app_zh.arb

Build

cd savitri-mobile
flutter pub get
flutter run          # debug
flutter build apk    # Android release
flutter build ios    # iOS release