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Overview

This guide shows how to implement passkey authentication in a Swift app using the Turnkey Swift SDK.
You’ll add the required platform configuration, set rpId, and call loginWithPasskey and signUpWithPasskey from your UI. The examples below use SwiftUI, but the SDK works with any Swift framework.

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Passkey setup

To enable passkeys on iOS, configure Associated Domains and provide an rpId that matches your domain.
  • Add Associated Domains in Xcode (Signing & Capabilities → Associated Domains):
    • webcredentials:yourdomain.com
  • For details, see Apple’s docs on Associated Domains.

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Set rpId in your SDK configuration

Ensure TurnkeyConfig has an rpId matching your Associated Domain, and set organizationId for login. 
import TurnkeySwift

let config = TurnkeyConfig(
  rpId: "yourdomain.com",
  organizationId: "<your_organization_id>",
  authProxyConfigId: "<your_auth_proxy_config_id>" // required for passkey sign-up
)
TurnkeyContext.configure(config)

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Usage

Below are examples for signing up and logging in with passkeys:

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Log in with passkey

Before calling loginWithPasskey, you must provide an ASPresentationAnchor. Apple requires a presentation context so the system can display the passkey UI in the correct window. We use a helper (defaultAnchor()) to resolve the active key window for this purpose.
  • Does not use Auth Proxy: loginWithPasskey runs entirely on-device and talks directly to Turnkey’s API using a stamp; no Auth Proxy involvement.
  • Session expiration: You can pass expirationSeconds to set the session lifetime. If omitted, the SDK resolves it in this order:
    1. Dashboard setting (when an Auth Proxy config is present and sessionExpirationSeconds is set), else
    2. Default of 900 seconds (15 minutes).
import SwiftUI
import AuthenticationServices
import TurnkeySwift

struct LoginWithPasskeyButton: View {
  @EnvironmentObject private var turnkey: TurnkeyContext

  var body: some View {
    Button("Log in with passkey") {
      Task {
        if let anchor = defaultAnchor() {
          // Optionally override session lifetime via `expirationSeconds`, e.g. "1800"
          try? await turnkey.loginWithPasskey(
            anchor: anchor
            // , expirationSeconds: "1800"
          )
        }
      }
    }
  }
}

private func defaultAnchor() -> ASPresentationAnchor? {
  UIApplication.shared
    .connectedScenes
    .compactMap { $0 as? UIWindowScene }
    .first(where: { $0.activationState == .foregroundActive })?
    .windows
    .first(where: { $0.isKeyWindow })
}

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Sign up with passkey

import SwiftUI
import AuthenticationServices
import TurnkeySwift

struct SignUpWithPasskeyButton: View {
  @EnvironmentObject private var turnkey: TurnkeyContext

  var body: some View {
    Button("Sign up with passkey") {
      Task {
        if let anchor = defaultAnchor() {
          try? await turnkey.signUpWithPasskey(anchor: anchor)
        }
      }
    }
  }
}
Notes:
  • signUpWithPasskey requires the Auth Proxy to be configured (authProxyConfigId), since signup creates a new sub-organization and user.
  • You can customize the passkey display name during signup:
try await turnkey.signUpWithPasskey(
  anchor: anchor,
  passkeyDisplayName: "passkey-\(Int(Date().timeIntervalSince1970))"
)

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Tips

  • Ensure your rpId exactly matches the domain configured in Associated Domains; otherwise passkey operations will fail.
  • Confirm your provisioning profile includes Associated Domains and your build contains the entitlements.

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Next steps

Social Logins

Set up OAuth-based logins (Google, Apple, Discord, X).