import type { SpanData } from '@genkit-ai/tools-common';
import type { Response } from 'express';
export interface SpanEvent {
    type: 'span_start' | 'span_end';
    traceId: string;
    span: SpanData;
}
export declare class BroadcastManager {
    private connections;
    subscribe(traceId: string, response: Response): void;
    unsubscribe(traceId: string, response: Response): void;
    broadcast(traceId: string, event: SpanEvent): void;
    close(traceId: string): void;
    getConnectionCount(traceId: string): number;
    hasConnections(traceId: string): boolean;
}