@natify/storage-mmkv

The High Performance Storage Adapter for the Natify Framework.
This package implements the IAsyncStorage interface using react-native-mmkv, which is roughly 30x faster than the standard AsyncStorage

Architectural Note: Although MMKV is synchronous by nature, this adapter wraps operations in Promises to maintain interchangeability with other IAsyncStorage implementations (like Keychain or filesystem-based storage).

Installation

Since this is an adapter, you must install both the package and its native driver (Peer Dependency) in your application.

$3

Bash

``
pnpm add @natify/storage-mmkv react-native-mmkv
`

$3

Bash

`
yarn add @natify/storage-mmkv react-native-mmkv
`

$3

After installation, you must install the pods for iOS and rebuild your application since MMKV uses C++ JSI bindings.

Bash

`
cd ios && pod install && cd ..


Rebuild the app


pnpm run android # or pnpm run ios
`

---

Setup & Integration

Register this adapter in your NatifyProvider configuration at the root of your application (App.tsx).

TypeScript

`
import { NatifyProvider } from '@natify/core';
import { MMKVAdapter } from '@natify/storage-mmkv';
import { AxiosHttpAdapter } from '@natify/http-axios';

// 1. Instantiate the adapter
// Optional: You can pass an instance ID for data isolation
const fastStorage = new MMKVAdapter('user-preferences');

// 2. Register in the config container
const config = {
// Register by specific name (recommended)
'storage-fast': fastStorage,

// Or register as the default 'storage' capability
'storage': fastStorage,

// ... other adapters
'http': new AxiosHttpAdapter()
};

export default function App() {
return (



);
}
`

---

Usage

Consume the storage anywhere in your components using the useAdapter hook. You don't need to import this package directly in your UI components, just use the Core interfaces.

$3

Get the first available adapter that handles 'storage'.

TypeScript

`
import { useAdapter } from '@natify/core';
import { IAsyncStorage } from '@natify/core/interfaces';

const SettingsScreen = () => {
// Returns the default storage adapter
const storage = useAdapter('storage');

const saveTheme = async () => {
await storage.setItem('theme', 'dark');
};
};
`

$3

If you registered it as 'storage-fast' in the config.

TypeScript

`
import { useAdapter } from '@natify/core';
import { IAsyncStorage } from '@natify/core/interfaces';

const CacheManager = () => {
// Explicitly request the fast storage (MMKV)
const fastStorage = useAdapter('storage-fast');

const clearCache = async () => {
await fastStorage.clear();
};
};
`

---

API Reference

This adapter fully implements IAsyncStorage.

| Method | Signature | Description |
| ------------ | -------------------------------------------------- | ------------------------------------------------- |
| getItem | getItem(key: string): Promise | Retrieves a value. Auto-parses JSON if possible. |
| setItem | setItem(key: string, value: T): Promise | Saves a value. Auto-stringifies objects/arrays. |
| removeItem | removeItem(key: string): Promise | Deletes a single key. |
| clear | clear(): Promise | Warning:Wipes all data in this MMKV instance. |

$3

- Property: capability
- Value: 'storage'

---

Troubleshooting

#### Error: MMKV JSI bindings are not installed

This means the native C++ code isn't linked.

1. Ensure you installed react-native-mmkv in your App's package.json.
2. Run cd ios && pod install.
3. Kill the Metro Bundler and restart with cache reset: pnpm start --reset-cache.
4. Rebuild the app binary (pnpm run ios / pnpm run android).

#### Unable to resolve module react-native-mmkv

If using a Monorepo, ensure react-native-mmkv` is hoisted or installed in the app's dependencies, not just inside the adapter.