​
Prerequisites

Before integrating passkey registration, ensure the following prerequisites are met. You may proceed to the Passkey Registration section if you have already configured the associated domains and the app site association file.

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Associated Domains Entitlement

Your app must have the Associated Domains capability enabled. This allows your app to access passkeys stored in the user’s iCloud Keychain. Ensure that your domain supports HTTPS and is properly configured.
  1. In Xcode, select your project and navigate to the Signing & Capabilities tab.
  2. Click the + Capability button and add Associated Domains.
  3. Add your domain to the Associated Domains section, prefixed with webcredentials:. For example:
webcredentials:your.domain.com
Reference: Apple Developer Documentation - Supporting Associated Domains

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Apple App Site Association File

Your domain must host an apple-app-site-association file that specifies the app identifiers allowed to access credentials. The file should be available at: 
https://your.domain.com/.well-known/apple-app-site-association
The content of the file should include the webcredentials service, as shown: 
{
  "webcredentials": {
    "apps": ["<your-app-prefix>.<your-app-bundle-id>"]
  }
}
Replace <your-app-prefix> and <your-app-bundle-id> with your actual App ID prefix and bundle identifier.

​
Passkey Registration

Once the prerequisites are in place, you can proceed to implement passkey registration using PasskeyManager.
1

Import Required Modules

At the top of your ViewController or relevant class, import the necessary modules:
ViewController.swift
import UIKit
import AuthenticationServices
import Shared  // Import Shared to use PasskeyManager
import TurnkeySDK    // Import TurnkeySDK to use TurnkeyClient
2

Initialize PasskeyManager

Create an instance of PasskeyManager, providing the Relying Party Identifier and the presentation anchor.
ViewController.swift
class ViewController: UIViewController {
    var passkeyManager: PasskeyManager?
    override func viewDidLoad() {
        super.viewDidLoad()
        // Additional setup if needed
    }
    // ... rest of the class
}
3

Set Up User Interface

Implement a method to initiate passkey registration, typically triggered by a user action such as tapping a button.The PasskeyManager requires two parameters:
  • rpId: The relying party identifier, typically your domain. This must match the domain configured in the Associated Domains entitlement and the apple-app-site-association file.
  • presentationAnchor: The window in which the authentication services will present UI, usually obtained from view.window.
ViewController.swift
ViewController.swift
@IBAction func registerPasskeyTapped(_ sender: Any) {
    guard let window = view.window else {
        print("No window available")
        return
    }

    let rpId = "your.domain.com"  // Replace with your actual domain
    let email = "user@example.com" // Replace with the user's email

    // Initialize PasskeyManager
    passkeyManager = PasskeyManager(rpId: rpId, presentationAnchor: window)

    // Register for passkey-related notifications
    // We'll define this method in the next step
    registerForPasskeyNotifications()

    // Start the passkey registration process
    passkeyManager?.registerPasskey(email: email)
}
4

Register for Notifications

To handle the results of the passkey registration process, register for the relevant notifications provided by PasskeyManager.
ViewController.swift
func registerForPasskeyNotifications() {
    NotificationCenter.default.addObserver(
        self,
        selector: #selector(passkeyRegistrationCompleted(_:)),
        name: .PasskeyRegistrationCompleted,
        object: nil
    )
    NotificationCenter.default.addObserver(
        self,
        selector: #selector(passkeyRegistrationFailed(_:)),
        name: .PasskeyRegistrationFailed,
        object: nil
    )
    NotificationCenter.default.addObserver(
        self,
        selector: #selector(passkeyRegistrationCanceled),
        name: .PasskeyRegistrationCanceled,
        object: nil
    )
}
5

Cleanup

Remove the observers when they are no longer needed to avoid memory leaks.
ViewController.swift
deinit {
    NotificationCenter.default.removeObserver(self)
}
6

Implement Notification Handlers

Define the methods that handle the passkey registration outcomes.
ViewController.swift
@objc func passkeyRegistrationCompleted(_ notification: Notification) {
    if let result = notification.userInfo?["result"] as? PasskeyRegistrationResult {
        // Handle successful registration
        print("Passkey registration completed.")
        print("Challenge: \(result.challenge)")
        print("Credential ID: \(result.attestation.credentialId)")
        // Send result to your server for verification and storage
    }
}

@objc func passkeyRegistrationFailed(_ notification: Notification) {
    if let error = notification.userInfo?["error"] as? PasskeyRegistrationError {
        // Handle registration failure
        print("Passkey registration failed with error: \(error.localizedDescription)")
        // Display an error message or take appropriate action
    }
}

@objc func passkeyRegistrationCanceled() {
    // Handle user cancellation
    print("Passkey registration was canceled by the user.")
    // Update UI or take appropriate action
}

​
Sign Up New User

After successful passkey registration, use the PasskeyRegistrationResult to sign up a new user by creating a sub-organization using the TurnkeyClient from the TurnkeySDK.
1

Initialize TurnkeyClient with Proxy

When handling the completion of passkey registration, set up the TurnkeyClient with a proxy server URL using the ProxyMiddleware. This configuration is essential for situations where the parent organization’s API keys are required to authenticate requests for creating a sub-organization. Your backend should relay the request to the Turnkey API, ensuring it is authenticated with the parent organization’s API keys.
ViewController.swift
func signUpWithPasskey(with passkeyRegistrationResult: PasskeyRegistrationResult) {
    Task {
        do {
            // Initialize the TurnkeyClient with a proxy server URL
            let turnkeyClient = TurnkeyClient(proxyURL: "https://your-proxy-server.com/api/turnkey-proxy")

            // Proceed to the next substep...

        } catch {
            print("Error signing up new user: \(error)")
            // Handle error appropriately
        }
    }
}
The middleware adds an X-Turnkey-Request-Url header to each request, which contains the original request URL. For more details, see the Proxy Middleware guide.
2

Attestation Object

Construct the attestation object using the PasskeyRegistrationResult.
ViewController.swift
let attestation = Components.Schemas.Attestation(
    credentialId: passkeyRegistrationResult.attestation.credentialId,
    clientDataJson: passkeyRegistrationResult.attestation.clientDataJson,
    attestationObject: passkeyRegistrationResult.attestation.attestationObject,
    transports: [.AUTHENTICATOR_TRANSPORT_BLE]  // Adjust transports as needed
)
3

Define Parameters

Set up the necessary parameters for the sub-organization and root user. We’ll use the passkeyRegistrationResult we received in the previous step to create a passkey authenticator for this new sub-organization.
ViewController.swift
let parentOrganizationId = "your-parent-organization-id"
let subOrganizationName = "New Sub Organization"

// This should come from the user's input
let email = "user@example.com"

let rootUsers: [Components.Schemas.RootUserParamsV4] = [
    .init(
        userName: email,
        userEmail: email,
        apiKeys: [],
        authenticators: [
            .init(
                // We use the passkey registration result to create the authenticator
                authenticatorName: "Passkey",
                challenge: passkeyRegistrationResult.challenge,
                attestation: attestation
            )
        ],
        oauthProviders: []
    )
]

let rootQuorumThreshold: Int32 = 1

// Create an Ethereum wallet for the new sub-organization
let wallet = Components.Schemas.WalletParams(
    walletName: "Default Wallet",
    accounts: [
        .init(
            curve: .CURVE_SECP256K1,
            pathFormat: .PATH_FORMAT_BIP32,
            path: "m/44'/60'/0'/0/0",
            addressFormat: .ADDRESS_FORMAT_ETHEREUM
        )
    ]
)

// Set optional parameters
let disableEmailRecovery = false
let disableEmailAuth = false
let disableSmsAuth = false
let disableOtpEmailAuth = false
4

You can find more information about the optional parameters in the Organization Features section of the documentation.
5

Create Sub-Organization

Use the TurnkeyClient to create the sub-organization with the provided parameters.
ViewController.swift
let output = try await turnkeyClient.createSubOrganization(
    organizationId: parentOrganizationId, // Organization ID can be empty when using proxy
    subOrganizationName: subOrganizationName,
    rootUsers: rootUsers,
    rootQuorumThreshold: rootQuorumThreshold,
    wallet: wallet,
    disableEmailRecovery: disableEmailRecovery,
    disableEmailAuth: disableEmailAuth,
    disableSmsAuth: disableSmsAuth,
    disableOtpEmailAuth: disableOtpEmailAuth
)
6

Handle the Response

Process the response from the createSubOrganization call to retrieve information about the new sub-organization and root users.
ViewController.swift
// Handle the response
switch output {
case let .ok(response):
    switch response.body {
    case let .json(activityResponse):
        if let result = activityResponse.activity.result.createSubOrganizationResultV7 {
            print("Created sub-organization: \(result.subOrganizationId ?? "Unknown ID")")
            if let rootUserIds = result.rootUserIds {
                print("Created root users: \(rootUserIds)")
            }
            // Proceed with additional setup or navigation as needed
        }
    }
case let .undocumented(statusCode, undocumentedPayload):
    if let body = undocumentedPayload.body {
        let bodyString = try await String(decoding: body, as: UTF8.self)
        print("Undocumented response body: \(bodyString)")
    }
    print("Undocumented response: \(statusCode)")
}

​
References