export interface GuestKey {
    /** base58 public key — the account address. */
    address: string;
    /** Sign a UTF-8 message; returns a base64 detached signature. */
    sign(message: string): Promise<string>;
    /** True when backed by a non-extractable WebCrypto key. */
    nonExtractable: boolean;
}
/** Get (or create) this device's durable guest key. */
export declare function getGuestKey(): Promise<GuestKey>;
/** Read the existing durable guest key without ever minting a replacement. */
export declare function getExistingGuestKey(): Promise<GuestKey | null>;
/** Forget the guest key on this device (a fresh signInAnonymously mints a new one). */
export declare function clearGuestKey(): Promise<void>;