import { BetterFetchError } from 'better-auth/react';
import { UsernameAuthClient } from '../../lib/auth-client';
export type IsUsernameAvailableParams<TAuthClient extends UsernameAuthClient> = Parameters<TAuthClient["isUsernameAvailable"]>[0];
export type IsUsernameAvailableOptions<TAuthClient extends UsernameAuthClient> = Omit<ReturnType<typeof isUsernameAvailableOptions<TAuthClient>>, "mutationKey" | "mutationFn">;
/**
 * Mutation options factory for checking username availability.
 *
 * Modeled as a mutation because callers typically trigger the check on
 * user action (debounced input, form submit) rather than on mount.
 *
 * @param authClient - The Better Auth client.
 */
export declare function isUsernameAvailableOptions<TAuthClient extends UsernameAuthClient>(authClient: TAuthClient): import('@tanstack/query-core').WithRequired<import('@tanstack/react-query').UseMutationOptions<{
    available: boolean;
}, BetterFetchError, IsUsernameAvailableParams<TAuthClient>, unknown>, "mutationKey">;
/**
 * Create a mutation for checking whether a username is available.
 *
 * Wraps `authClient.isUsernameAvailable` and forwards React Query mutation
 * options such as `onSuccess`, `onError`, and `retry`.
 *
 * @param authClient - The Better Auth client with the username plugin.
 * @param options - React Query options forwarded to `useMutation`.
 */
export declare function useIsUsernameAvailable<TAuthClient extends UsernameAuthClient>(authClient: TAuthClient, options?: IsUsernameAvailableOptions<TAuthClient>): import('@tanstack/react-query').UseMutationResult<{
    available: boolean;
}, BetterFetchError, IsUsernameAvailableParams<TAuthClient>, unknown>;