Registry / storage / react-native-mmkv-storage

react-native-mmkv-storage

library12.0.1jsnpmunverified

A fast and reliable key-value storage library for React Native, wrapping Tencent's MMKV (used by WeChat). Version 12.0.1 is current, with updates driven by RN breaking changes. It uses JSI for synchronous C++ operations (no async gaps), supports multiple encrypted instances, and ships TypeScript types. Unlike async-storage or simple MMKV wrappers, it offers React hooks (useMMKVStorage, useIndex) and 0.0002s read/write. Released under MIT, maintained on GitHub.

storage

npm install react-native-mmkv-storage

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · REACT-NATIVE-MMKV-

react-native-mmkv-storage

storagejavascriptv12.0.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

MMKVLoader

✓ import { MMKVLoader } from 'react-native-mmkv-storage'

✗ import MMKVLoader from 'react-native-mmkv-storage'

Named export, not default. Use destructured import.

useMMKVStorage

✓ import { useMMKVStorage } from 'react-native-mmkv-storage'

✗ import { useMMKVStorage } from 'react-native-mmkv-storage/hooks'

Hook is exported from root package, not a sub-path.

MMKV

✓ import { MMKV } from 'react-native-mmkv-storage'

✗ import { MMKV } from 'react-native-mmkv-storage/MMKV'

MMKV is the instance returned by MMKVLoader().initialize(). It is exported directly.

Shows initialization with MMKVLoader, useMMKVStorage hook for reactive state, and sync set. Typescript works without extra types.

import { MMKVLoader, useMMKVStorage } from 'react-native-mmkv-storage'; const storage = new MMKVLoader().initialize(); function App() { const [name, setName] = useMMKVStorage('name', storage, 'Guest'); const [count, setCount] = useMMKVStorage('count', storage, 0); return ( <View> <Text>Hello, {name}!</Text> <Text>Count: {count}</Text> <Button title="Increment" onPress={() => setCount(c => c + 1)} /> </View> ); }

Debug

Known issues

breakingv0.9.0 requires React Native >= 0.71.0

fix

Upgrade to React Native 0.71+ or stick with v0.8.x

affects: >=0.9.0

breakingv0.5.0 rewritten in C++ using JSI, breaking older versions

fix

Re-link native modules and update initialization to new MMKVLoader API

affects: >=0.5.0

deprecatedv0.6.0 deprecated older initializer patterns like 'new MMKVStorage.Loader()'

fix

Use 'new MMKVLoader().initialize()' instead

affects: >=0.6.0

gotchauseMMKVStorage hook only works inside React components; outside component context use storage methods directly

fix

Use storage.getString('key') outside components, not hook

affects: >=0.5.5

gotchaEncryption requires passing a password to MMKVLoader.setEncryptionKey() before initialize()

fix

Always call setEncryptionKey() before initialize() if you need encryption. Cannot change later.

affects: >=0.5.0

Errors

Common errors & fixes

TypeError: Cannot read property 'getString' of undefined

storage instance not initialized or imported incorrectly (e.g., missing .initialize() or using wrong import pattern)

fix

Ensure you call 'new MMKVLoader().initialize()' and check import: use '{ MMKVLoader }' not default import.

Invariant Violation: Tried to register two views with the same name

Duplicated native module registration (often due to linking both old and new versions)

fix

Run 'cd ios && pod deintegrate && pod install' and ensure only one version of MMKVStorage is in node_modules.

fatal: Not a git repository (or any of the parent directories): .git

Running pod install without git repository

fix

Initialize a git repo with 'git init' before 'pod install' or add '--no-repo-update'

React Native version mismatch. JavaScript version: 0.73.4, Native version: 0.72.0

MMKV native library compiled for different RN version

fix

Update both React Native and MMKVStorage to compatible versions, run pod install again.

Upgrade

Version history

12.0.1latest on npm

Audit

Dependencies

react-nativerequiredpeer dependency - requires React Native runtime

Agent activity

28 hits · last 30 days

node

OpenAI (training)

Resources

githubhttps://github.com/ammarahm-ed/react-native-mmkv-storage ↗

packagereact-native-mmkv-storage ↗

homepagehttps://github.com/ammarahm-ed/react-native-mmkv-storage#readme ↗