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.
🌟 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
🧠 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
📦 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.
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 
dotnet add package LangMate.Core
✅ Sample Usage
You can see Full Documentation and sample usage in this link as well.
🧠 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
📡 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.
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🖼️ 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).
🛠️ Build and Test
dotnet build --configuration Release
dotnet test
📬 Contributing
Contributions are welcome!
- Fork the repo and create your branch
- Implement your feature or fix
- Submit a PR with proper context
📄 License
Licensed under the MIT License.
📣 Contact
Created and maintained by @raminesfahani.
For issues and features, open a GitHub Issue.
🙏 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.