RN Storage Kit

Unified storage for React Native. One interface — fast key-value, encrypted secrets, and structured logs.

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rn-storage-kit gives you three batteries-included storage primitives behind a single, consistent async get/set/remove/clear interface:

Primitive	Backed by	Use for
MMKVStorageAdapter	react-native-mmkv	Preferences, cache, state
SecureStorageAdapter	react-native-keychain	Tokens, passwords, secrets
Logger	MMKV-persisted, TTL-aware	Debug traces, production safety

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Installation

npm install @devraj-labs/rn-storage-kit

Peer dependencies

npm install react-native-mmkv react-native-keychain

Follow the native setup guides for both libraries:

• react-native-mmkv setup
• react-native-keychain setup

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Usage

MMKV storage

Fast, synchronous storage wrapped in a promise-based interface.

import { MMKVStorageAdapter } from '@devraj-labs/rn-storage-kit';

const storage = new MMKVStorageAdapter();
// optionally scope to a named MMKV instance:
const storage = new MMKVStorageAdapter('my-app.settings');

await storage.set('theme', 'dark');
const theme = await storage.get('theme');   // 'dark'
await storage.remove('theme');
await storage.clear();
const keys = await storage.getAllKeys();

Secure storage (Keychain)

Identical interface — swap the adapter, get hardware-backed encryption.

import { SecureStorageAdapter } from '@devraj-labs/rn-storage-kit';

const secure = new SecureStorageAdapter();

await secure.set('auth_token', 'eyJ...');
const token = await secure.get('auth_token');
await secure.remove('auth_token');
await secure.clear();
const keys = await secure.getAllKeys();

Secure values are stored in Keychain via setGenericPassword per key. A key index is maintained in a dedicated MMKV instance (rn-storage-kit.secure-index) so getAllKeys and clear work without Keychain enumeration support.

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Logger

Production-safe structured logging for every storage operation. Disabled by default.

Enable

Call once at app startup, before any storage operations:

import { enableLogger } from '@devraj-labs/rn-storage-kit';

enableLogger({
  level: 'debug',           // 'none' | 'error' | 'info' | 'debug'
  maxEntries: 200,          // FIFO cap (default: 200)
  ttl: 0,                   // auto-evict entries older than N ms (0 = off)
  allowInProduction: false, // never logs in prod unless explicitly set
});

Disable

import { disableLogger } from '@devraj-labs/rn-storage-kit';

disableLogger();

Read and clear logs

import { getLogs, clearLogs } from '@devraj-labs/rn-storage-kit';

const entries = getLogs(); // TStorageLogEntry[]
clearLogs();

Subscribe to new entries

import { onNewLog, offNewLog } from '@devraj-labs/rn-storage-kit';

const handler = (entry) => console.log(entry);
onNewLog(handler);
// later:
offNewLog(handler);

Log levels

Level	What is recorded
none	Nothing
error	Failed operations only
info	All operations — key and adapter visible, values/results stripped
debug	Full detail — key, value, result, duration. Secure values are always masked as ***

Log entry shape

type TStorageLogEntry = {
  id: string;
  timestamp: number;
  adapter: 'mmkv' | 'secure';
  operation: 'set' | 'get' | 'remove' | 'clear' | 'getAllKeys';
  key?: string;
  value?: string;   // '***' for secure ops; absent at info level
  result?: string | null;
  error?: string;
  durationMs: number;
  secure: boolean;
};

Persistence

Logs survive Metro fast-refresh via a dedicated MMKV instance (rn-storage-kit.logs). Writes are async via setImmediate — zero impact on storage call performance. Secure values never reach the log store.

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Production safety

• Logger is a no-op in production unless allowInProduction: true is passed to enableLogger.
• Secure adapter values are always logged as ***, regardless of log level.
• At info level, value and result fields are stripped from all log entries.

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API reference

MMKVStorageAdapter

Method	Signature	Description
constructor	(id?: string)	Custom MMKV instance ID. Default: 'rn-storage-kit.default'
get	(key: string) => Promise<string | null>	Returns value or null
set	(key: string, value: string) => Promise<void>	Stores a string value
remove	(key: string) => Promise<void>	Deletes a key
clear	() => Promise<void>	Clears the entire MMKV instance
getAllKeys	() => Promise<string[]>	Returns all stored keys

SecureStorageAdapter

Same interface as MMKVStorageAdapter. Backed by Keychain via setGenericPassword / getGenericPassword per service key.

Logger

Export	Signature	Description
enableLogger	(options?: TLoggerOptions) => void	Activates logging
disableLogger	() => void	Deactivates logging
getLogs	() => TStorageLogEntry[]	Returns a copy of all current entries
clearLogs	() => void	Clears entries from memory and MMKV
onNewLog	(cb: TLogListener) => void	Subscribe to new entries
offNewLog	(cb: TLogListener) => void	Unsubscribe

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Project structure

src/
  mmkv-storage/    MMKVStorageAdapter + TStorageAdapter type
  secure-storage/  SecureStorageAdapter (Keychain-backed)
  logger/          Logger state, enableLogger, log levels, MMKV persistence
  types/           Shared type definitions
  index.ts         Public barrel

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License

MIT