> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getpara.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Custom Storage with MMKV

> Configure Para client to use MMKV storage in React Native applications

Para's React Native SDK uses AsyncStorage and Keychain Storage by default. However, you can configure Para to use MMKV for improved performance. This guide shows you how to implement a custom storage solution using the MMKV library.

## Installation

First, install the MMKV package:

```bash theme={null}
npm install react-native-mmkv
# or
yarn add react-native-mmkv
```

## Implementation

Create your MMKV storage instance and configure Para to use it:

```typescript theme={null}
import { MMKV } from 'react-native-mmkv';
import { ParaMobile } from '@getpara/react-native-wallet';

// Initialize MMKV storage instances
const storage = new MMKV({
  id: 'para-storage'
});

// Initialize Para client with MMKV storage
const para = new ParaMobile(
  "YOUR_API_KEY", 
  undefined,
  {
    // Custom storage overrides
    localStorageGetItemOverride: async (key) => {
      const value = storage.getString(key);
      return value ?? null;
    },
    
    localStorageSetItemOverride: async (key, value) => {
      storage.set(key, value);
    },
    
    sessionStorageGetItemOverride: async (key) => {
      const value = storage.getString(key);
      return value ?? null;
    },
    
    sessionStorageSetItemOverride: async (key, value) => {
      storage.set(key, value);
    },
    
    sessionStorageRemoveItemOverride: async (key) => {
      storage.delete(key);
    },
    
    clearStorageOverride: async () => {
      storage.clearAll();
    }
  }
);

export { para };
```

<Note>
  The custom storage implementation must handle serialization and deserialization of JSON data. All values are stored as strings, so your implementation should handle converting values correctly.
</Note>