import { type FormMetadata } from '@defra/forms-model';
import Boom from '@hapi/boom';
export interface OfflineBoomData {
    offline: true;
    metadata: FormMetadata;
}
/**
 * Throws when the form has been taken offline. The plugin's
 * unavailable-response extension catches the marker and renders the
 * "Sorry, this form is unavailable" view at HTTP 200.
 */
export declare function assertFormAvailable(metadata: FormMetadata): void;
/** Type guard for the offline Boom marker. */
export declare function isOfflineBoom(err: unknown): err is Boom.Boom<OfflineBoomData> & {
    data: OfflineBoomData;
};
