import type { FastifyRequest, FastifyReply } from 'fastify';
import type { SessionData } from '@fastify/secure-session';
declare module '@fastify/secure-session' {
    interface SessionData {
        flash: {
            [k: string]: string[];
        };
    }
}
type FlashData = SessionData['flash'];
export type ReplyReturn = FlashData | string[];
export declare function flashFactory(): {
    request(this: FastifyRequest, type: string, ...message: string[] | [string[]]): number;
    reply(this: FastifyReply, type?: string): ReplyReturn;
};
export {};