Building an AI-Powered Personal Assistant with React Native and Google Gemini

Introduction

After work hours, I set out to build Aura — a cross-platform AI personal assistant that could actually understand voice commands, schedule events intelligently, and send push reminders. What seemed like a weekend project turned into 10+ iterations of debugging Android-specific quirks.

Tech Stack

• React Native (Expo) — cross-platform mobile framework
• TypeScript — for type safety across the codebase
• Google Gemini API — the AI brain powering voice commands and scheduling
• Supabase — backend-as-a-service for auth and data
• Zustand — lightweight global state management
• Expo Notifications — push reminders

Key Features Built

1. Passwordless OTP Authentication

Instead of passwords, users authenticate via a one-time code sent to their email — cleaner UX, more secure.

2. Gemini AI Voice Commands

Integrating the Gemini API for voice input was the most exciting part. The flow looks like this:

User speaks → Speech-to-text → Gemini prompt → Parsed intent → Action

3. AI-Powered Event Scheduling

Gemini interprets natural language like "Remind me to call mom tomorrow at 6pm" and creates structured calendar events automatically.

Hardest Challenges on Android

Android was brutal. Key issues I resolved:

• Voice input handling — Android's SpeechRecognizer behaves differently per OEM
• Microphone permission flows — required custom rationale dialogs
• Message bubble rendering glitches — caused by FlatList re-render timing

Lessons Learned

1. Always test on real Android devices early — emulators lie.
2. Gemini API responses need careful prompt engineering for consistent JSON output.
3. Zustand kept global state simple — no Redux overkill for a solo app.

Conclusion

Building Aura taught me that AI integration is only 20% of the challenge — the other 80% is making the mobile UX feel native and reliable. The full source is on GitHub.