How to combine on-device inference with cloud sync — without paying a cent in API fees The Unspoken Reality of AI API Costs Here’s the moment every indie developer dreads. You’ve shipped your AI feature. Users love it. It’s working. Then you open your billing dashboard. Every question your users ask costs you money. Every summary generated, every classification run, you’re paying for it. You have created a successful product, but its popularity is now draining your resources. What if there was a way to run powerful AI in your Flutter app with zero ongoing API costs? No per-request charges. No server bills. No privacy risk from data leaving the device. That’s exactly what the combination of Gemma 4 and Firebase unlocks. Gemma does the thinking, entirely on the user’s phone. Firebase handles persistence and sync. The result is an AI-powered app that scales to thousands of users at near-zero marginal cost. I’m building my own product on this exact stack. Here’s how it works.…