@anywalletkit/backup-cloud

@anywalletkit/backup-cloud

Cloud backups for React Native wallets built on the SDK. Each seed or key becomes one encrypted @anywalletkit/seed-vault file in the app’s hidden iCloud Drive container. The user picks how it opens:

Install

npm install @anywalletkit/backup-cloud
# or: pnpm add @anywalletkit/backup-cloud  ·  yarn add @anywalletkit/backup-cloud

On npm: @anywalletkit/backup-cloud, published from the release workflow with provenance. An Expo native module (expo-modules-core is its peer, already in every Expo app): use a development build, not Expo Go.

Option	Where the pieces live	Who can open it
iCloud Keychain (no password)	File in iCloud Drive; its 32-byte key in iCloud Keychain (end-to-end encrypted by Apple)	This app on the user’s Apple devices, after Face ID / Touch ID / the device passcode. Neither the file nor the key opens anything alone.
Password	File in iCloud Drive	Anyone with the backup password, on any phone (Argon2id, ≥10 characters)
Both	—	Either one

import { iCloudDrive, iCloudKeychain, saveBackup, checkBackup, listBackups, restoreBackup } from '@anywalletkit/backup-cloud'

const store = iCloudDrive({ container: 'iCloud.com.example.wallet' })
const keys = iCloudKeychain()

await saveBackup({ store, keyVault: keys, password, secret: await secrets.get(source.id), meta: { type: source.type, fingerprint: source.fingerprint, label: source.label } })
await checkBackup(store, source)                 // { present, createdAt, protectors } — no prompt, nothing opened
const opened = await restoreBackup({ store, name, keyVault: keys, expect: source })  // or { password }
await secrets.set(id, opened.text()); opened.dispose()

Protection on the device.

• The key: WhenUnlocked. It is never readable while the phone is locked, after-first-unlock included. Keys written by 0.1.0 are raised to this class on their next read.
• Reading it: the native module asks for the device owner (Face ID / Touch ID / passcode) before handing the key out, so app code can’t read it silently. One confirmation covers 30 s, so a multi-wallet backup or restore asks once. Creating a new key asks for nothing.
• The file: written with complete file protection.
• No strict mode: a synced keychain item can’t carry a biometric ACL, so the no-password option can’t honour strict biometrics-only mode. Offer the password option to users who want that.

saveBackup reads the file back and compares it before reporting success. restoreBackup refuses another wallet’s backup when given expect. A device without the synced key gets key-missing, and can then use the password.

Setup (Expo)

["@anywalletkit/backup-cloud", { "iCloudContainer": "iCloud.<your bundle id>" }]

The plugin adds the iCloud Documents entitlements for your container. Every app has its own container, because a shared one would let apps read each other’s backups.

With automatic signing, Xcode registers the container on your team. xcodebuild -allowProvisioningUpdates needs an Apple ID in Xcode › Settings › Accounts.

Files go to <container>/WalletBackups, not Documents/, so they stay out of the Files app. iCloud Keychain needs no entitlement.

Status

Supported today: iOS (iCloud Drive and iCloud Keychain).

Next: Android, with Google Drive appDataFolder (needs your OAuth client) and Block Store.

On Android, status() reports unavailable.

Classes

• CloudBackupError

Interfaces

• BackupInfo
• BackupStore
• ICloudDriveOptions
• ICloudKeychainOptions
• KeyVault
• NativeBackupCloud
• NativeDriveFile
• RestoreBackupOptions
• SaveBackupOptions
• StoredFile

Type Aliases

• CloudBackupErrorCode

Functions

• backupFileName
• checkBackup
• iCloudDrive
• iCloudKeychain
• isCloudBackupError
• listBackups
• restoreBackup
• saveBackup