MauMind - Offline-First Local RAG Assistant

A privacy-centric cross-platform application built with .NET MAUI that leverages on-device AI to create a personal knowledge assistant. The app implements a Retrieval-Augmented Generation (RAG) pipeline entirely on the edge.

📱 Features

• 🔒 Privacy-First: All data stays on your device - no cloud, no tracking
• 🤖 AI-Powered: Ask questions about your documents using local AI
• 📄 Document Management: Add notes, daily logs, and import PDFs
• ⚡ Offline: Works completely offline with on-device AI models
• 🎨 Modern UI: Beautiful Material Design with full dark/light theme support
• 🌐 Web Search: Privacy-first web search via DuckDuckGo integration
• ♿ Accessible: Full screen reader support with semantic labels
• 📱 Responsive: Optimized layouts for phones and tablets
• 📖 Onboarding: First-launch tutorial for new users

🛠️ Tech Stack

• .NET 10.0 MAUI - Cross-platform framework
• C# - Programming language
• Refit - Type-safe HTTP client (Firebase, DuckDuckGo)
• Microsoft Semantic Kernel - AI orchestration
• ONNX Runtime - On-device AI inference
• SQLite - Local database with vector storage
• Phi-3 Mini - Small Language Model (SLM)
• CommunityToolkit.MVVM - MVVM pattern support
• DuckDuckGo API - Privacy-first web search integration

🚀 Getting Started

Prerequisites

• .NET 10.0 SDK (or later)
• Visual Studio 2022 (17.8+) or VS Code
• Android SDK with API 21+ (for Android builds)
• MAUI workload installed: dotnet workload install maui-android
• Xcode 15+ (for iOS builds - optional, currently deferred)

Installation

# Install MAUI workload for Android
dotnet workload install maui-android

# Restore dependencies
dotnet restore

Build

# Build for Android (currently active)
dotnet build -c Release -f net10.0-android

# Publish for Android
dotnet publish -c Release -f net10.0-android

Run (Development)

# Run on Android emulator/device
dotnet run -f net10.0-android

📦 GitLab CI/CD

The project includes a GitLab CI/CD pipeline (.gitlab-ci.yml) that:

1. Builds the Android APK on every commit
2. Releases to GitLab artifacts on tags
3. Pushes to Indus App Store (configurable)

CI/CD Variables

Configure these in your GitLab project settings:

Pipeline Stages

┌──────────┐     ┌─────────┐
│  Build   │────▶│ Release │
│ Android  │     │  Store  │
└──────────┘     └─────────┘

Usage

1. Automatic builds: Push to main branch triggers build
2. Release: Create a tag to trigger release:

   git tag v1.0.0
   git push origin v1.0.0
   

📁 Project Structure

MauMind.App/
├── Models/              # Data models (Document, Folder, ChatMessage, etc.)
├── ViewModels/          # MVVM ViewModels (ChatViewModel, DocumentsViewModel, etc.)
├── Views/               # MAUI Pages (ChatPage, DocumentsPage, SettingsPage, etc.)
├── Controls/            # Reusable UI components (ChatBubbleView, DocumentCardView)
├── Services/            # Business logic layer
│   ├── *Api.cs          # Refit HTTP interfaces
│   ├── *Service.cs      # Core services (Chat, Web Search, Model Management)
│   └── *Manager.cs      # Data management (ModelManager)
├── Data/                # Database context & operations
├── Resources/           # Assets, styles, color resources
│   └── Styles/          # XAML style definitions (theme-aware)
├── Platforms/           # Platform-specific code
│   └── Android/         # Android platform head (MainActivity, etc.)
└── MauiProgram.cs       # DI container & MAUI configuration

Key Architectural Patterns

• MVVM with CommunityToolkit.MVVM
• Dependency Injection via Microsoft.Extensions.DependencyInjection
• Type-safe HTTP via Refit
• Theme-aware UI with AppThemeBinding and centralized Colors.xaml
• Reusable Controls with BindableProperties for data binding
• Accessibility-first with SemanticProperties labels

📄 License

MIT License - See LICENSE file for details.

🙏 Acknowledgments

• Microsoft Semantic Kernel
• ONNX Runtime
• Phi-3 Mini Model
• .NET MAUI Community