Zebra Alex - Investec Private Banking AI Assistant App & Balance/Transactions Widget

An offline-first Android application and Home Screen Widget for Investec Private Banking. It integrates secure local database caching, biometric security, a Jetpack Glance home screen widget, and an on-device AI assistant ("Alex") powered by Google LiteRT (formerly TensorFlow Lite) using Gemma.

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🚀 Key Features

• 🏦 Investec OpenAPI Integration:
  • Retrieves accounts, real-time balances, transaction postings, and credit cards.
  • Supports transferring funds and paying configured beneficiaries.
• 📴 Offline-First Room Caching:
  • Automatically caches accounts and transactions using Android Room to keep the app and home screen widget functional offline.
• 📱 Jetpack Glance Home Screen Widget:
  • Displays primary account details, available balance, sync status, and recent postings (color-coded by credit/debit).
  • Integrates secure tap-to-unlock actions.
• 🔒 Biometric Security & Widget Auto-Locking:
  • Access to sensitive financial info is protected using the Android Biometric prompt.
  • Automatically locks the home screen widget 5 seconds after exiting the app or when the screen turns off (via Android AlarmManager) to prevent unauthorized viewing.
• 🤖 On-Device AI Financial Assistant ("Alex"):
  • Powered by Google LiteRT-LM running a local model (gemma-4-E2B-it.litertlm on device CPU, optimized with 4 threads).
  • Equipped with a BankingToolSet allowing you to query accounts, transaction history, and check balances using natural language in a secure, privacy-preserving chat interface.

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🛠️ Project Structure

The codebase is organized into key modules:

• app/src/main/java/com/example/MainActivity.kt: MainActivity.kt - Entry Activity handling biometric authentication, state management, widget alarm scheduling, and app navigation.
• app/src/main/java/com/example/ui/dashboard/:
  • DashboardScreen.kt - Renders the main dashboard, including profile selections, account cards, transaction history lists, and secure settings management.
  • DashboardViewModel.kt - Manages account states, sync events, and interacts with the repository.
• app/src/main/java/com/example/ui/chat/:
  • ChatScreen.kt - Natural chat UI representing conversation bubbles.
  • ChatViewModel.kt - Handles conversation context, LiteRT engine initialization, and streaming inferences.
• app/src/main/java/com/example/receiver/BankWidgetProvider.kt:
  • BankWidgetProvider.kt - Logic for updating the Jetpack Glance Widget, evaluating biometric lock states, and checking session expiry.
• app/src/main/java/com/example/data/:
  • ai/: Contains LiteRtEngineManager.kt (LM lifecycle) and BankingToolSet.kt (agent function calling registry).
  • api/: InvestecApiService.kt - Retrofit network client configuration and service definitions for the Investec OpenAPI.
  • local/: Room Database configuration, Account and Transaction Entity DAOs.
  • repository/: BankRepository.kt - Managing data synchronization, credential accessors, database updates, and payments.
• app/src/main/assets/:
  • system_prompt.txt - The system instruction prompt defining rules, guidelines, and formatting styles for the AI assistant.

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⚙️ Getting Started

1. Prerequisites

• Android Studio (Koala or newer recommended).
• Android SDK 35/36 target compatibility.
• An emulator or physical device supporting Biometric Authentication.

2. Set Up Local Gemma Model (LiteRT)

The AI assistant runs a local language model. You must supply a compatible LiteRT model file:

1. Obtain the gemma-4-E2B-it.litertlm model. Hugging Face
2. Push the model to the target device's local tmp directory via ADB:

   adb push path/to/gemma-4-E2B-it.litertlm /data/local/tmp/

3. Open API Credentials Setup

The application comes preconfigured to run in Sandbox Mode using open-access sandboxed credentials. To connect to your live Investec accounts:

1. Open the app and tap the Settings (gear) icon in the top right.
2. Disable Developer Sandbox Mode.
3. Supply your Client ID, Client Secret, and x-api-key obtained from the Investec Developer Portal.
4. Tap Apply & Sync to fetch your actual accounts and transactions securely.

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🧪 Testing

The project is fully integrated with:

• Compose UI Tests and Robolectric for local behavior verification.
• Roborazzi for screenshot testing.
• To run tests:

  ./gradlew test

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Roadmap

1. Android App and Widget
2. Android Watch Tile and LLM download option
3. iOS App