import Joi from "joi" ; see https export interface NFC { message : string ; encryptionPublicKey : string ; requiresAuthentication ? : boolean ; } export const NFC = Joi . object < NFC > ( ) . keys ( { message : Joi . string ( ) . required ( ) . max ( 64 ) , encryptionPublicKey : Joi . string ( ) . required ( ) , requiresAuthentication : Joi . boolean ( ) , } ) ;