> How would I "move" the passkeys, as they'd still be tied to the old domain? You can also use a combination of Related Origin Requests[1], Conditional Create,

> How would I "move" the passkeys, as they'd still be tied to the old domain? You can also use a combination of Related Origin Requests[1], Conditional Create, and Signal API to allow the passkey for the old site to be used on your new site, automatically create a new passkey for the new domain, and optionally tell the user's credential manager that the old passkey is no longer valid. [1] https://passkeys.dev/docs/advanced/related-origins/ https://passkeys.dev/docs/advanced/related-origins/