Chainlit

Chainlit is an open-source async Python framework for building production-ready conversational AI and LLM-powered chat applications with minimal boilerplate. It auto-generates a ChatGPT-style React chat UI from pure Python decorator-based code, eliminating the need for frontend development skills. It supports deployment as standalone web apps, embedded copilots, FastAPI servers, and bots for Slack, Discord, and Teams, with integrations for LangChain, OpenAI, Anthropic, and other LLM providers. Originally created by Chainlit SAS (Paris, France), the project became community-maintained under Apache 2.0 license as of May 2025.