AI provider

QuickSkill uses the Vercel AI SDK as an abstraction layer. The provider is currently hardcoded to Google Gemini in api/src/lib/ai.ts (GOOGLE_GENERATIVE_AI_API_KEY from aistudio.google.com/apikey). Because the AI SDK abstracts the provider interface, switching to OpenAI or Anthropic is a small code change, not a rewrite — but it's not a one-line flip: swap the provider import in ai.ts, install the new provider's package if it isn't already a dependency, update the API key, and re-test your prompts against the new model.

The AI layer is used by the content pipeline (turning raw material into lessons and exercises) and by any in-app AI surfaces you build on top of the starter kit. Keep provider API keys server-side, in api/.env — never ship them to the Expo client.