Brownfield integration

Info

Brownfield integration is supported on Android, iOS, and macOS.

AsyncStorage is built on a shared storage layer (SharedStorage) that can also be accessed directly from native code.
This is especially useful in brownfield scenarios, where your app combines React Native and native code, allowing both layers to read from and write to the same storage consistently.

All platforms provide a thread-safe singleton registry called StorageRegistry to manage storage instances.

Android

On Android, StorageRegistry is a public singleton, which is used to share SharedStorage instances with the native module. Multiple calls with the same name return the same singleton instance, ensuring consistent access.

import android.content.Context
import kotlinx.coroutines.runBlocking
import org.asyncstorage.shared_storage.Entry
import org.asyncstorage.shared_storage.SharedStorage
import org.asyncstorage.storage.StorageRegistry

// access shared storage via StorageRegistry
val storage: SharedStorage = StorageRegistry.getStorage(ctx, "my-users")

// runBlocking only for a demonstration
runBlocking {
    storage.setValues(listOf(Entry("email", "john@example.com")))
    val values = storage.getValues(listOf("email"))
    println("Stored email: ${values.firstOrNull()?.value}")
}

iOS / macOS

On iOS and macOS, the StorageRegistry singleton provides the same functionality in Swift and Objective-C.

import AsyncStorage
import SharedAsyncStorage

// access shared storage via StorageRegistry
let storage: SharedStorage = StorageRegistry.shared.getStorage(dbName: "my-users")

Task {
    storage.setValues([Entry(key: "email", value: "john@example.com")])
    let values = storage.getValues(keys: ["email"])
    print("Stored email: \(values.first?.value ?? "none")")
}