Passkeys are built on the FIDO2 standard (CTAP2 + WebAuthn standards). They remove the shared secret, stop phishing at the source, and make credential-stuffing useless.
But adoption is still low, and interoperability between Apple, Google, and Microsoft isn’t seamless.
I broke down how passkeys work, their strengths, and what’s still missing
KeePassXC has begun rollout of their own implementation, and I’m pretty sure they’re considered FOSS.
From a quick scan of the white paper, it appears they’re currently using on-device passkey discovery and otherwise “intercepting” passkey registration workflows, which I take to mean they aren’t originating the request as a passkey registrar. This may be the easiest method to satisfy FIDO’s dID requirements.