Chainlit

Chainlit is an open-source Python framework for rapidly building production-ready conversational AI applications without frontend expertise. It provides a decorator-based API that auto-generates a polished chat UI with real-time streaming, authentication, and data persistence, letting developers focus entirely on LLM logic. It integrates natively with major LLM providers and frameworks including OpenAI, Anthropic, LangChain, LlamaIndex, and HuggingFace, and supports multi-platform deployment as a standalone web app, embedded copilot, FastAPI server, or Slack/Discord/Teams bot. As of May 2025, the original Chainlit team has stepped back and the project is community-maintained under an open-source maintainer agreement.