> ## Documentation Index
> Fetch the complete documentation index at: https://docs.portalhq.io/llms.txt
> Use this file to discover all available pages before exploring further.

# FirebaseStorage

> Storage implementation for Firebase Auth Backup and recovery.

**Class Definition**

```swift theme={null}
public class FirebaseStorage: Storage, PortalStorage
```

`FirebaseStorage` handles storing and retrieving backup encryption keys using Firebase Authentication. It communicates with Portal's secure enclave using Firebase ID tokens for authentication.

**Initializer**

```swift theme={null}
public init(
  getToken: @escaping () async throws -> String?
)
```

**Parameters**

* `getToken`: A callback that returns a fresh Firebase ID token. This is called before each request to the secure enclave to ensure the token is valid. The callback should call Firebase's `getIDToken()` method internally. Return `nil` if no user is signed in.

**Errors**

`FirebaseStorage` can throw the following errors:

* `FirebaseStorageError.noApiKey`: The client API key has not been set on the `FirebaseStorage` instance. This means the storage was not registered via `portal.registerBackupMethod()`.
* `FirebaseStorageError.tokenUnavailable`: The `getToken` callback returned `nil`. Ensure the user is signed in to Firebase before performing backup or recovery.
* `FirebaseStorageError.unexpectedResponse(String)`: The secure enclave returned an unexpected response.
* `FirebaseStorageError.requestFailed(underlying: Error)`: A non-401 request to the secure enclave failed. The underlying error contains details about the failure.

**Example Usage**

```swift theme={null}
import FirebaseAuth
import PortalSwift

// Create a FirebaseStorage instance
let firebaseStorage = FirebaseStorage(
  getToken: {
    guard let user = Auth.auth().currentUser else {
      return nil
    }
    return try await user.getIDToken(forcingRefresh: true)
  }
)

// Register it with Portal
portal.registerBackupMethod(.Firebase, withStorage: firebaseStorage)

// Now you can use .Firebase for backup and recovery
let (cipherText, storageCallback) = try await portal.backupWallet(.Firebase)
try await storageCallback()
```

**Related Documentation**

* [Firebase Auth Backup](../guide/back-up-a-wallet#firebase-auth-backup)
* [registerBackupMethod reference](./registerbackupmethod)
* [backupWallet reference](./backupwallet)
* [recoverWallet reference](./recoverwallet)