MultiAI — Multi-LLM Desktop Client

A sleek, native Windows desktop application built with WinUI 3 and .NET 8 that provides a unified interface for interacting with Google Gemini, OpenAI, and Anthropic Claude.

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Features

• Multi-Provider Support: Seamlessly switch between Google Gemini, OpenAI (GPT-4o, o1), and Anthropic Claude (Claude 3.7, 3.5 Sonnet & Haiku).
• Real-Time Token Streaming: Token-by-token streaming response rendering powered by asynchronous enumerables (IAsyncEnumerable<string>).
• Clean MVVM Architecture: Built with CommunityToolkit.Mvvm separating UI views from business logic and LLM provider implementations.
• Local SQLite History: Chat sessions and messages are stored locally at %LOCALAPPDATA%\MultiAI\history.db.
• Automatic Smart Titling: Automatically summarizes new conversations into clean 3-5 word titles using fast background requests.
• Secure Key Vault: API keys are securely stored in the Windows Credential Manager (PasswordVault).
• Markdown & Code Highlighting: Rich markdown text rendering with full code block support.
• Automated Unit Testing & CI: Includes xUnit test suite (MultiAI.Tests) and GitHub Actions build verification.

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API Key Configuration

To start using MultiAI with your desired providers:

1. Open Settings from the sidebar navigation menu.
2. Enter your API key in the respective section:
   • Google Gemini: Obtain from Google AI Studio.
   • OpenAI: Obtain from OpenAI Developer Portal.
   • Anthropic: Obtain from Anthropic Console.
3. Click Validate Key to test connection, then click Save Key. Your keys are encrypted and stored in Windows Credential Locker.

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Tech Stack

• UI Framework: WinUI 3 (Windows App SDK)
• Runtime: .NET 8.0 (net8.0-windows10.0.19041.0)
• MVVM: CommunityToolkit.Mvvm 8.2
• Database: SQLite (sqlite-net-pcl)
• OpenAI SDK: OpenAI 2.1
• Testing: xUnit 2.7

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Getting Started

Prerequisites

• Windows 10 (version 1809 or higher) or Windows 11
• .NET 8.0 SDK
• Visual Studio 2022 (with .NET Desktop Development and Windows App SDK workloads)

Build & Run

# Restore dependencies
dotnet restore MultiAI.slnx

# Build the solution (x64)
dotnet build MultiAI.slnx -p:Platform=x64

# Run unit tests
dotnet test MultiAI.Tests/MultiAI.Tests.csproj -p:Platform=x64

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License

MIT License