MMKVStorageAdapter

The MMKVStorageAdapter uses MMKV for high-performance, encrypted storage. Recommended for most apps.

Installation

npm install react-native-mmkv
# or
bun add react-native-mmkv

For iOS, run pod install:

cd ios && pod install

Usage

import { TeardownCore } from '@teardown/react-native';
import { ExpoDeviceAdapter } from '@teardown/react-native/adapters/expo';
import { MMKVStorageAdapter } from '@teardown/react-native/adapters/mmkv';

export const teardown = new TeardownCore({
  org_id: 'your-org-id',
  project_id: 'your-project-id',
  api_key: 'your-api-key',
  storageAdapter: new MMKVStorageAdapter(),
  deviceAdapter: new ExpoDeviceAdapter(),
});

Import Path

import { MMKVStorageAdapter } from '@teardown/react-native/adapters/mmkv';

Benefits

• Synchronous - No async/await needed for reads/writes
• Encrypted - Data encrypted by default
• Fast - Memory-mapped for optimal performance
• Small - Minimal bundle size impact
• Reliable - Used by WeChat with 1B+ users

How It Works

MMKV uses memory-mapped files for storage:

1. Data is written to memory
2. OS flushes to disk asynchronously
3. Reads are instant (from memory)
4. Crash-safe with journaling

Requirements

• react-native-mmkv >= 2.0.0
• React Native >= 0.71

Platform Notes

iOS

• Requires pod install
• Data stored in app's sandboxed Documents directory
• Encrypted with iOS Keychain

Android

• Works out of the box
• Data stored in app's private directory
• Encrypted with Android KeyStore

Expo Compatibility

For Expo managed workflow, you need a development build:

npx expo install react-native-mmkv
npx expo prebuild

Or use EAS Build for production.