Chainlit

Chainlit is an open-source Python framework for developers building conversational AI apps with their own application logic. You can run the app on your own server and give users a browser chat interface. It's a framework for creating an app, rather than a ready-made chatbot with a fixed model.

Its main appeal is the choice of where that conversation lives. An app can stand alone on the web or appear as an embedded copilot inside another product. Chainlit also supports custom React frontends, FastAPI deployments and bots for Slack, Discord and Teams.

Developers can customize the frontend and create their own chat components. Authentication supports simple sign-in methods and OAuth providers such as GitHub, Google, Azure and Okta, so access control can sit alongside the conversation interface.

Chainlit integrates with LangGraph and LlamaIndex, as well as model providers and tools including OpenAI, Mistral and HuggingFace. That makes it relevant to teams choosing a chat interface around an existing AI stack. Self-hosting the interface doesn't make a connected cloud model local: where model requests go depends on the backend the application uses.

The framework uses the Apache 2.0 license and is community-maintained. Community maintainers handle code review, releases and security.