Thanks for being a part of WWDC25!

How did we do? We’d love to know your thoughts on this year’s conference. Take the survey here

Passkey returns unknown error instead of excludedCredentials error when “Saving on another device” option is used.

Hello, I'm receiving an unknown error instead of the excluded credentials error when using the "Save on another device" option for Passkey creation.

When creating the ASAuthorizationPlatformPublicKeyCredentialProvider request to pass to the ASAuthorizationController. The excludedCredentials property is used to add a list of credentials to exclude in the registration process. This is to prevent duplicate passkeys from being created if one already exists for the user.

When trying to create a duplicate passkey using the same device, the ASAuthorizationControllerDelegate method authorizationController(controller, didCompleteWithError:) is called. The error received has localized description “At least one credential matches an entry of the excludeCredentials list in the platform attached authenticator."

When trying to create a duplicate passkey using the “Save on another device” option. The delegate method is called, but the error received has code 1000 ("com.apple.AuthenticationServices.AuthorizationError" - code: 1000). Which maps to the unknown error case in ASAuthorization error type.

Passkey returns unknown error instead of excludedCredentials error when “Saving on another device” option is used.
 
 
Q