credential.get() for both Passkey and FedCM in one call - what's the plan? #835

This is a question / discussion as I couldn't find any discussion about this on the web, apologies if this was already covered elsewhere.

• We'd like to let visitors sign-in with either their passkey or FedCM, with a (very strong) preference for passkey.
• We'd also like to avoid explicit buttons, and rely on conditional mediation for passkeys.
• Today, there's no way to present both options to the visitor, at least from the API perspective:
  • conditional.get() with identity fails when mediation is conditional, at least on recent Chrome versions.
  • Conversely, when mediation is optional, and a passkey is not available for use, browsers (at least Chrome) will show a confusing UI saying that a passkey is not available.
• Ideally, we could get Android's Credential Manager behavior, and show multiple authentication providers in a unified UI:

Am I missing something obvious on how to do this on FedCM-supported browsers?