OptionalreadA boolean that indicates that the Relying Party would like to fetch the previously-written blob associated with the asserted credential. Only valid during authentication.
OptionalsupportOnly valid during registration.
OptionalwriteAn opaque byte string that the Relying Party wishes to store with the existing credential. Only valid during authentication.
LargeBlob extension inputs
See
https://w3c.github.io/webauthn/#dictdef-authenticationextensionslargeblobinputs