LangMate

LangMate is a modular and extensible AI chat application and SDK platform built with .NET 9 and fully compatible with .NET Aspire.
It provides a Blazor-powered Web UI, Ollama model integrations, persistent chat history via MongoDB, and a flexible SDK for .NET developers to integrate and use local LLMs (like Gemma, LLaMA2, Mistral) easily and securely.

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🌟 Key Features

• ⚙️ Fully compatible with .NET Aspire
• 💬 Chat UI
  • built with Blazor Server (interactive, reactive experience)
• 🧠 Ollama Integration
  • LLM-based completion and conversation
• 🗃 MongoDB Chat History and caching
  • for persistent and fast retrieval
• 🔧 LangMate.Core SDK
  • use Ollama easily in your own .NET apps
• 🧩 Pluggable Middleware
  • Polly-powered Resiliency, Circuit Breakers, and Retry logic
• 🚀 File Upload Support
  • with base64 image preview support (for image input models)
• 🌐 API Endpoints
  • Implemented a backend-driven project for using in every client app
• 🧰 Developer-Friendly architecture — clean, testable and maintainable

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🧠 Architecture

LangMate/
├── Apps/
├──── LangMate.AppHost.AppHost        → .NET Aspire for orchestrating and deploying the apps on Docker, Kubernetes, or any other cloud platform.
├──── LangMate.AppHost.BlazorUI        → Blazor ChatBot UI sample project using LangMate SDK
├──── LangMate.AppHost.ApiService        → Web API sample project using LangMate SDK
├── SDK/
├──── LangMate.Core               → Reusable .NET SDK to interact with Ollama
├──── LangMate.Middleware         → Polly-based Resiliency Middleware (retry, timeout, circuit breaker)
├──── LangMate.Extensions         → Utilities, helpers and extension methods
├──── LangMate.Persistence        → MongoDB chat history, caching layer, repositories and configuration

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📦 Installation

Prerequisites

• .NET 9 SDK
• Ollama installed and running locally (for model inference)
• MongoDB (locally or cloud instance)

Run the App

git clone https://github.com/raminesfahani/LangMate.git
cd LangMate/src/apps/LangMate.AppHost.AppHost

# Restore dependencies and build
dotnet restore
dotnet build

# Run the .NET Aspire Dashboard
dotnet run

Then open https://localhost:17198/ in your browser to see the .NET Aspire dashboard. You can launch Blazor ChatBot or Web API apps over there by their own links.

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LangMate.Core SDK

LangMate.Core is a lightweight, extensible .NET SDK designed to make working with Ollama-powered local AI models seamless and developer-friendly. It abstracts away the complexity of managing conversations, interacting with Ollama endpoints, and persisting chat history — all while offering resiliency, caching, and extensibility.

📦 Installation

To use LangMate.Core, install the required NuGet package , or include the project reference in your solution.

dotnet add package LangMate.Core

✅ Sample Usage

You can see Full Documentation and sample usage in this link as well.

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🧠 LangMate Blazor Chat UI

The LangMate Blazor App is an intelligent, real-time chat UI built with Blazor Server and integrated with the powerful local AI models provided by Ollama using LangMate.Core SDK.

It provides a complete frontend experience for interacting with AI models, managing chat history, uploading files, and dynamically updating chat state.

✨ Features

• 🔁 Chat with Ollama Models: Seamlessly send and stream messages from local Ollama instances.

• 💬 Persistent Conversations: Every chat session is stored in MongoDB and can be resumed anytime.

• 📂 File Uploads: Upload image files and pass them to models like llava for multimodal interactions.

• 🧭 Sidebar Navigation: Access previous chats and start new ones from a clean sidebar UI.

• 📦 Model Switching: Easily switch between available Ollama models.

• 🔃 Streaming Responses: Uses async streaming to display tokens as they’re generated.

• ☁️ Resilient Middleware: Protected with timeout, retry, and circuit breaker policies.

• 🔔 Global Error Toasts: All unhandled exceptions surface as toast notifications.

Screenshots

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📡 LangMate WebAPI

The LangMate API Service is the backend layer of the LangMate system, exposing RESTful HTTP APIs for external integration, orchestration, and automation.

It serves as a stateless gateway for interacting with the LangMate core functionalities — such as chat sessions, file uploads, model management, and streaming chat completions — powered by the LangMate.Core SDK and Ollama.

✨ Features

• 🔗 Chat Completion API: Start or continue chat sessions supporting stream mode with local Ollama models.

• 🧠 Model Discovery: Query available and pulled models from the Ollama runtime.

• 💬 Conversation APIs: Read, delete, and manage persistent chat history.

• 🖼️ File Upload: Upload image files to be used with multimodal models (e.g., gemma).

• 🔐 Middleware-Enhanced Resilience: Protected by retry, timeout, and circuit breaker policies via LangMate.Middleware.

• ⚙️ Scalar Integration: Auto-generated OpenAPI documentation (easily added).

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🛠️ Build and Test

dotnet build --configuration Release
dotnet test

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📬 Contributing

Contributions are welcome!

1. Fork the repo and create your branch
2. Implement your feature or fix
3. Submit a PR with proper context

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📄 License

Licensed under the MIT License.

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📣 Contact

Created and maintained by @raminesfahani.
For issues and features, open a GitHub Issue.

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🙏 Acknowledgements

This project uses the Ollama repository for local AI model integration. I am thankful to the maintainers and contributors of Ollama for making this technology available.