I am looking to build a conversational AI assistant using Flutter. I’ve heard about the new Google AI Dart SDK. How do I securely handle the API keys so they aren't exposed in the frontend code? Also, what is the best way to implement a streaming response UI so the text appears token-by-token like in ChatGPT?
3 answers
To integrate Gemini securely, you should never hardcode the API key in your main.dart. Instead, use a backend proxy (like a Firebase Function) to make the actual request. If you're prototyping, use --dart-define to pass keys as environment variables. For the UI, the google_generative_ai package provides a generateContentStream() method. You can wrap this in a StreamBuilder in Flutter. This allows you to listen to each new chunk of text as it arrives and append it to your chat bubble, creating that smooth "typing" effect that users expect from modern generative AI applications.
When using StreamBuilder, how do you prevent the entire list of messages from flickering or rebuilding every time a new token arrives? It seems to affect performance on older Android devices.
I've found that using the flutter_markdown package is essential here. Since Gemini often returns responses in markdown format, it helps in rendering bold text and code blocks beautifully.
Great point, Justin. Markdown rendering makes the AI responses look much more professional, especially for technical queries or formatted lists.
Brandon, you should use a ListView.builder combined with a specialized state management approach like Bloc or Riverpod. Instead of rebuilding the whole list, only the "active" message widget should listen to the stream. By using the RepaintBoundary widget around your chat bubbles, you can isolate the animations and ensure the rest of the UI stays static. This significantly reduces the GPU load, keeping the scrolling smooth even on mid-range devices while the AI is generating a long response.