BotSharp
BotSharp is an open-source AI agent application framework written in C# on .NET, meant to connect LLMs to an existing business application. The README lists built-in multi-agent support with conversation and state management, several LLM planning approaches, RAG interfaces with memory-based vector search, agents with different responsibilities cooperating on a task, building, testing, evaluating and auditing agents in one place, a SvelteKit admin UI, rich-content integration with channels such as Facebook Messenger, Slack and Telegram, a REST API plus WebSocket, and MCP integration with visual management.
The kernel is kept small and most functions are plugins. Core modules include a plugin loader, hooks, authentication, agent profiles, conversation and state, routing and planning, templating, caching and LLM providers. Plugins cover data storage (MongoDB, LiteDB), LLMs (OpenAI, Azure OpenAI, Anthropic, Google, DeepSeek, Meta, HuggingFace, LLamaSharp, Semantic Kernel and others), messaging (ChatHub, Messenger, Twilio, Telegram, WeChat), RAG (knowledge base, Qdrant) and vision (PaddleSharp). To try it, run the WebStarter project with `dotnet run` and start the separate BotSharp UI with npm, then open localhost:5015. It is Apache-2.0 licensed.