A complete chat interface — message bubbles, a typing state, and a streaming-friendly backend — that talks to any OpenAI-compatible API. Set LLM_API_KEY (and optionally LLM_BASE_URL and LLM_MODEL) and it works immediately; until then it shows a friendly setup screen so the preview never errors. Stdlib only, no database. A perfect base for a support bot, a product assistant, or your own AI app.