In these threads, it was clarified that Credential Provider Extensions must set both Backup Eligible (BE) and Backup State (BS) flags to 1 in authenticator data: https://developer.apple.com/forums/thread/745605 https://developer.apple.com/forums/thread/787629 However, I'm developing a passkey manager that intentionally stores credentials only on the local device. My implementation uses: kSecAttrAccessibleWhenUnlockedThisDeviceOnly for keychain items kSecAttrTokenIDSecureEnclave for private keys No iCloud sync or backup These credentials are, by definition, single-device credentials. According to the WebAuthn specification, they should be represented with BE=0, BS=0. Currently, I'm forced to set BE=1, BS=1 to make the extension work, which misrepresents the actual backup status to relying parties. This is problematic because: Servers using BE/BS flags for security policies will incorrectly classify these as synced passkeys Users who specifically want device-bound credentials for higher security cannot get accurate flag representation Request: Please allow Credential Provider Extensions to return credentials with BE=0, BS=0 for legitimate device-bound passkey implementations. Environment: macOS 26.2 (25C56), Xcode 26.2 (17C52)

I'm developing a passkey manager using ASCredentialProviderViewController. I've set a custom AAGUID in the attestation object during registration: let aaguid = Data([ 0xec, 0x78, 0xfa, 0xe8, 0xb2, 0xe0, 0x56, 0x97, 0x8e, 0x94, 0x7c, 0x77, 0x28, 0xc3, 0x95, 0x00 ]) However, when I test on webauthn.io, the relying party receives: AAGUID: 00000000-0000-0000-0000-000000000000 Provider Name: "iCloud Keychain" It appears that macOS overwrites the AAGUID to all zeros for third-party Credential Provider Extensions. This makes it impossible for relying parties to distinguish between different passkey providers, which is one of the key purposes of AAGUID in the WebAuthn specification. Is this expected behavior? Is there a way for third-party Credential Provider Extensions to use their own registered AAGUID? Environment: macOS 26.2 Xcode 26.2