/**
 * Second-factor methods a user can complete the challenge with.
 *
 * `totp` and `otp` come from the server's `twoFactorMethods` list. Backup
 * codes are always available when the server has them enabled, so they are
 * never part of that list.
 */
export type TwoFactorMethod = "totp" | "otp";
/**
 * `sessionStorage` key holding the methods reported by the sign-in response.
 *
 * Only the non-sensitive method names are stored — never a code, token, or
 * the two-factor cookie, which stays HTTP-only.
 */
export declare const TWO_FACTOR_METHODS_STORAGE_KEY = "better-auth-ui.two-factor-methods";
/**
 * Sign-in response shape Better Auth returns instead of a session when a
 * second factor is required.
 */
export type TwoFactorRedirect = {
    twoFactorRedirect: true;
    /**
     * Left as `unknown` on purpose: the redirect flag is what decides the
     * navigation, and a malformed method list must never turn into a claim the
     * caller can trust. {@link parseTwoFactorMethods} does the narrowing.
     */
    twoFactorMethods?: unknown;
};
/**
 * Detect the `twoFactorRedirect` payload in a sign-in response.
 *
 * Better Auth deliberately withholds the session until the second factor
 * succeeds, so every sign-in strategy has to check for this before treating a
 * successful response as authenticated.
 *
 * @param data - Resolved data of a sign-in mutation.
 */
export declare function isTwoFactorRedirect(data: unknown): data is TwoFactorRedirect;
/**
 * Narrow arbitrary method names to the ones the challenge view can render.
 *
 * @param methods - Raw `twoFactorMethods` from the sign-in response.
 */
export declare function parseTwoFactorMethods(methods?: unknown): TwoFactorMethod[];
/**
 * Persist the enabled methods so the challenge view knows which options to
 * offer after the navigation.
 *
 * @param methods - Raw `twoFactorMethods` from the sign-in response.
 */
export declare function storeTwoFactorMethods(methods?: unknown): void;
/**
 * Read the methods stored by the sign-in continuation.
 *
 * Returns every method when nothing was stored (e.g. the challenge view was
 * opened directly) so the user still gets a way in.
 */
export declare function readTwoFactorMethods(): TwoFactorMethod[];
/** Clear the stored methods once the challenge is finished or abandoned. */
export declare function clearTwoFactorMethods(): void;