🛡️ Expo AI Context Shield

The ultimate privacy layer for Expo apps. Protect sensitive UI from AI vision, Screen Captures (iOS), and System Intelligence.

In 2025/2026, OS-level AI (like Google’s Gemini Nano and Samsung’s Galaxy AI) can "read" your app's screen to provide context. While helpful, this poses a massive privacy risk for apps handling bank balances, health data, or private credentials.

expo-ai-context-shield provides a semantic security boundary that makes your content invisible to AI OCR and system intelligence without compromising user experience or causing rendering bugs.

[!WARNING] iOS Support: The iOS implementation is based on native security APIs but has not been tested on physical devices yet. Contributions and feedback are welcome!

🚀 Key Features

• AI Vision Blocking: Prevents on-device AI (Circle to Search, Gemini Nano, Galaxy AI) from indexing or "reading" your sensitive UI.
• Hardware-Level Protection: Automatically blocks screenshots and screen recordings on both iOS and Android using native security layers.
• Zero Rendering Bugs: Optimized for React Native to ensure your content never disappears or "blinks" when security is toggled.
• Zero Performance Overhead: Pure native implementation with no background listeners or heavy wrappers.

📦 Installation

npx expo install expo-ai-context-shield

💡 Why this module?

The Privacy Risk in the Gen-AI Era

You might think: "If the user triggered the AI, they know what they are doing". In reality, the risk is more subtle:

• Context Leakage: When a user uses Circle to Search to identify a shoe, the AI captures the entire screen. If a bank balance or CPF is visible next to it, that sensitive data is sent to AI servers as "context".
• Activity Logs: AI assistant captures are often saved in the user's account history (Google/Samsung/Apple). Without protection, your app's private data ends up stored permanently in third-party logs.
• Always-on Snapshots: Features like "Recall" or "System Timelines" take periodic screenshots of the screen. This module ensures your app is a "black hole" in those automated captures.

Comparison

| Feature | Standard View | FLAG_SECURE (Full App) | AI Context Shield | | --- | --- | --- | --- | | Protects against AI | ❌ | ✅ | ✅ | | Blocks Screenshots | ❌ | ✅ | ✅ | | UX Friendly | ✅ | ❌ | ✅ | | OCR Resistant | ❌ | ✅ | ✅ |

🛠 Usage

Simply wrap your sensitive components with the AiContextShield.

import { AiContextShield } from 'expo-ai-context-shield';
import { Text, View } from 'react-native';

export default function SensitiveScreen() {
  return (
    <View style={{ flex: 1 }}>
      <Text>Public information (visible to AI)</Text>

      {/* This part will be blacked out in screenshots and invisible to Gemini/Galaxy AI */}
      <AiContextShield isSensitive={true} style={{ padding: 10 }}>
        <Text style={{ fontSize: 24, fontWeight: 'bold' }}>
          Balance: $1,250,000.00
        </Text>
      </AiContextShield>
    </View>
  );
}

🏥 Common Use Cases

| Industry | What to protect? | | --- | --- | | Fintech | Account balances, Credit Card numbers, CVV, QR Codes. | | Healthcare | Patient names, diagnoses, exam results. | | Messaging | Private chat content, self-destructing photos. | | Auth | Recovery keys, 2FA codes, temporary passwords. |

⚙️ API Reference

AiContextShield (Component)

| Prop | Type | Default | Description | | --- | --- | --- | --- | | isSensitive | boolean | false | When true, enables hardware-level protection. | | style | ViewStyle | undefined | Standard React Native styles. | | children | ReactNode | required | The content you want to shield. |

📱 Platform Implementation

• Android (API 29+): Uses IMPORTANT_FOR_CONTENT_CAPTURE_NO_EXCLUDE_DESCENDANTS to block data indexing and FLAG_SECURE to block visual pixel capture. Tested on Samsung S23/S24 (Galaxy AI) and Pixel 8/9 (Gemini).
• iOS (13.4+): Implements a hidden UITextField canvas layer trick. (Note: Not yet tested on physical devices).
• Web: Transparent fallback. Renders a standard View to maintain layout consistency.

🤝 Contributing

We are looking for help with:

• Improving the instance counter for FLAG_SECURE on Android.
• iOS screenshot detection events.

1. Fork the repo.
2. Install dependencies: npm install.
3. Test in the example app: cd example && npx expo run:android.

📄 License

MIT © @mensonones