import { Request, Response } from "express";
import { Context } from "../../types";
export type EventType = "features" | "features-updated";
export declare class SSEManager {
    private scopedChannels;
    private appContext;
    constructor(appContext: Context);
    subscribe(req: Request, res: Response): void;
    getSubscriberCount(apiKey: string): number | null;
    getSubscriberCounts(): Record<string, number>;
    publish({ apiKey, event, payload, oldPayload, }: {
        apiKey: string;
        event: EventType;
        payload: any;
        oldPayload?: any;
        remoteEvalEnabled?: boolean;
    }): void;
    closeAll(): void;
    private getScopedChannel;
}
export type EventStreamManager = SSEManager | null;
export declare let eventStreamManager: SSEManager | null;
export declare const initializeEventStreamManager: (appContext: Context) => void;