import type { ServiceEvent } from './types.js';
export type GatewaySseListener = (event: ServiceEvent) => Promise<void> | void;
export declare class GatewaySseHub {
    private eventCounter;
    private subscribers;
    private eventBuffers;
    subscribe(sessionId: string, listener: GatewaySseListener): () => void;
    emit(type: string, payload: unknown): void;
    getEventsSince(sessionId: string, lastEventId: string): ServiceEvent[];
}
