native-update/docs/api/FEATURES.md

Foundation package for building a comprehensive update system for Capacitor apps. Provides architecture and interfaces but requires backend implementation.

# Capacitor Native Update - Features

This document outlines all the features that will be implemented in the Capacitor Native Update plugin.

## Overview

The Capacitor Native Update plugin provides a comprehensive solution for managing app updates across three key areas:

1. **Live Updates (OTA)** - Deploy web assets instantly without app store approval
2. **Native App Updates** - Manage app store updates with native UI
3. **App Reviews** - Request user reviews at optimal moments

## 1. Live Update Features (OTA)

### Bundle Management

- **Download Management**
  - Progressive download with resume capability
  - Background download support
  - Bandwidth throttling options
  - Delta updates (only download changed files)
  - Bundle size optimization

- **Version Control**
  - Semantic versioning support (major.minor.patch)
  - Bundle version separate from native app version
  - Version compatibility checks
  - Minimum native version requirements

- **Storage Management**
  - Multiple bundle storage
  - Automatic cleanup of old bundles
  - Configurable retention policies
  - Bundle size limits

### Update Strategies

- **Immediate Update**
  - Force update on app launch
  - Block app usage until update completes
  - Show progress indicator

- **Background Update**
  - Download in background
  - Apply on next app restart
  - Silent updates without user interaction

- **Manual Update**
  - Programmatic control over update process
  - Custom update UI support
  - User-triggered updates

### Rollback & Recovery

- **Automatic Rollback**
  - Detect failed updates
  - Automatic revert to previous version
  - Crash detection after update

- **Manual Rollback**
  - Programmatic rollback to specific versions
  - Keep multiple versions for safety

- **Update Confirmation**
  - "Ready" confirmation mechanism
  - Grace period before confirming update
  - Telemetry on update success

### Update Channels

- **Multiple Channels**
  - Production, staging, development
  - Beta testing channels
  - A/B testing support
  - Geographic targeting

- **Channel Management**
  - Dynamic channel switching
  - Channel-specific configurations
  - User segmentation

### Security Features (Following Capacitor Security Guidelines)

- **Encryption**
  - End-to-end encryption for bundles
  - AES-256-GCM encryption with authenticated encryption
  - Secure key management using platform keystores
  - Never embed encryption keys in code

- **Signature Verification**
  - Public key bundle signing (RSA-2048 minimum)
  - RSA/ECDSA signature support
  - Certificate pinning for update servers
  - Signature timestamp validation

- **Integrity Checks**
  - SHA-256 checksum validation (minimum)
  - SHA-512 support for enhanced security
  - Bundle tampering detection
  - Secure manifest files with nested signatures
  - File size validation to prevent resource exhaustion

- **Network Security**
  - HTTPS enforcement (no HTTP fallback)
  - Certificate validation and pinning
  - Secure TLS configuration (TLS 1.2+)
  - Update server whitelist support

- **Storage Security**
  - Temporary files in secure directories
  - Immediate cleanup of failed downloads
  - File permissions set to app-only access
  - Secure storage for sensitive configuration

- **Input Validation**
  - Sanitize all JavaScript inputs
  - Path traversal prevention
  - URL validation and whitelist checking
  - Version string format validation

### Analytics & Monitoring

- **Update Metrics**
  - Download success rates
  - Update application rates
  - Rollback frequencies
  - Performance impact metrics

- **Error Tracking**
  - Detailed error logging
  - Network failure handling
  - Storage error management

## 2. Native App Update Features

### Update Detection

- **Version Checking**
  - Check current vs available versions
  - Version code and name comparison
  - Update availability detection
  - Update size information

- **Update Priority**
  - Critical updates (must update)
  - Recommended updates
  - Optional updates
  - Custom priority levels

### Update Types

- **Immediate Updates**
  - Blocking UI during update
  - Force update for critical fixes
  - Update progress tracking
  - Automatic app restart

- **Flexible Updates**
  - Background download
  - User-controlled installation
  - Download progress notifications
  - Install at convenient time

### Platform Integration

- **Android Features**
  - Google Play Core integration
  - In-app update API support
  - Play Store navigation
  - Update state persistence

- **iOS Features**
  - App Store version checking
  - iTunes API integration
  - App Store redirect
  - Version comparison logic

### Update UI

- **Native Dialogs**
  - Platform-specific update prompts
  - Customizable messaging
  - Localization support
  - Action button customization

- **Custom UI Support**
  - Programmatic update flow
  - Custom dialog integration
  - Progress indicators
  - Update postponement

## 3. App Review Features

### Review Prompts

- **In-App Reviews**
  - Native review dialogs
  - No app switching required
  - Platform-optimized experience
  - Fallback mechanisms

- **Smart Triggering**
  - Optimal timing detection
  - User engagement tracking
  - Positive experience detection
  - Configurable triggers

### Rate Limiting

- **Platform Limits**
  - iOS: Maximum 3 times per year
  - Android: Quota management
  - Custom rate limiting
  - User preference tracking

- **Intelligent Scheduling**
  - Avoid review fatigue
  - Track previous requests
  - User sentiment analysis
  - Conditional triggering

### Analytics

- **Review Metrics**
  - Request success rates
  - User interaction tracking
  - Conversion metrics
  - Platform-specific analytics

## 4. Configuration & Management

### Plugin Configuration

```typescript
{
  // Live Update Configuration
  liveUpdate: {
    appId: string;
    serverUrl: string;
    channel: string;
    autoUpdate: boolean;
    updateStrategy: 'immediate' | 'background' | 'manual';
    publicKey?: string;
    checkInterval?: number;
    allowEmulator?: boolean;
  },

  // App Update Configuration
  appUpdate: {
    minimumVersion?: string;
    updatePriority?: number;
    storeUrl?: {
      android?: string;
      ios?: string;
    };
    checkOnAppStart?: boolean;
  },

  // App Review Configuration
  appReview: {
    minimumDaysSinceInstall?: number;
    minimumDaysSinceLastPrompt?: number;
    minimumLaunchCount?: number;
    customTriggers?: string[];
    debugMode?: boolean;
  },

  // Security Configuration
  security: {
    enforceHttps?: boolean; // Default: true
    certificatePinning?: {
      enabled: boolean;
      certificates: string[]; // SHA256 fingerprints
      maxAge?: number;
    };
    requireSignature?: boolean; // Default: true
    validateChecksums?: boolean; // Default: true
    maxBundleSize?: number; // Default: 50MB
    allowedUpdateServers?: string[]; // Whitelist
    secureStorage?: boolean; // Default: true
  }
}
```

### Error Handling

- Comprehensive error codes without exposing system details
- User-friendly error messages
- Detailed internal logging (without sensitive data)
- Recovery strategies for common failures
- Fallback mechanisms for degraded functionality
- Security event logging and monitoring

### Testing Support

- Debug mode for development (disabled in production)
- Update simulation with mock servers
- Force update triggers (development only)
- Review prompt testing
- Security testing tools
- Malformed bundle testing
- Certificate validation testing

## 5. Web Platform Support

### Progressive Web Apps

- Service worker integration
- Cache management
- Update notifications
- Background sync

### Web Fallbacks

- Graceful degradation
- Feature detection
- Browser compatibility
- Update simulations

## 6. Security Implementation Details

### Platform-Specific Security

#### iOS Security

- **Keychain Services** for storing encryption keys and sensitive data
- **App Transport Security** enforcement (no HTTP allowed)
- **Code signing** validation for update bundles
- **Sandbox validation** for all file operations
- **Entitlements** properly configured for network access

#### Android Security

- **Android Keystore** for cryptographic key storage
- **Network Security Config** for certificate pinning
- **Runtime permissions** for storage and network access
- **ProGuard/R8** obfuscation for release builds
- **SafetyNet** integration for device attestation

### Security Protocols

- **Update Protocol**
  1. HTTPS request with certificate validation
  2. Server authentication via API keys
  3. Bundle download with progress tracking
  4. Checksum verification (SHA-256/512)
  5. Signature verification (RSA/ECDSA)
  6. Secure extraction to temporary directory
  7. Validation of bundle contents
  8. Atomic installation with rollback capability

- **Key Management**
  - Public keys distributed with app
  - Private keys secured on update server
  - Key rotation support with versioning
  - Hardware-backed key storage when available

### Threat Mitigation

- **Man-in-the-Middle**: Certificate pinning, HTTPS enforcement
- **Bundle Tampering**: Cryptographic signatures, checksums
- **Downgrade Attacks**: Version validation, no downgrades by default
- **Path Traversal**: Input sanitization, sandboxed operations
- **Resource Exhaustion**: File size limits, timeout controls
- **Replay Attacks**: Timestamp validation, nonce usage

## 7. Performance Optimizations

### Resource Management

- Memory efficient downloads with streaming
- Disk space pre-check before download
- CPU usage optimization with background threads
- Battery awareness (defer updates on low battery)
- Network state monitoring

### Network Optimization

- Intelligent retry with exponential backoff
- Connection type detection (WiFi preferred)
- Bandwidth throttling options
- CDN support with geographic distribution
- Resume capability for interrupted downloads
- Delta update support to minimize download size

## 8. Compliance and Privacy

### Data Protection

- GDPR compliance with data minimization
- No personal data collection in update process
- Anonymous usage statistics (opt-in)
- Secure data transmission and storage
- Right to erasure support

### App Store Compliance

- iOS App Store guidelines compliance
- Google Play Store policy adherence
- Transparent update notifications
- User consent for major updates
- No code injection or dynamic frameworks

## 9. Future Enhancements

### Planned Features

- Machine learning for optimal update timing
- Predictive pre-loading
- Peer-to-peer update distribution
- Advanced A/B testing framework
- Custom update UI components
- Update scheduling APIs
- Differential compression algorithms