FIM One is an open-source agent platform for enterprises that need to connect heterogeneous systems — ERP, CRM, HR, databases, and messaging platforms across global and China stacks — through a single agent brain. It supports any LLM via OpenAI-compatible API, provides built-in tools for enterprise connectors (Feishu, WeCom, DingTalk, etc.), function-calling, RAG capabilities, and Model Context Protocol integration. The platform is self-hostable and built with Python/FastAPI on the backend and Next.js on the frontend.