Add AI Chat Feature to Existing React App (Small Project)

I have a React web app and want to add a simple AI-powered chat assistant to it. The app is already built and working; this is a focused addition, not a rebuild. What I need: A clean chat interface component in React (message list, input, loading state)... (Budget: $15 - $25 USD, Jobs: AI Chatbot Development, AI Development, Django, FastAPI, Flask, Git, JavaScript, Next.js, OpenAI, Python)