export interface SSEOptions {
    fetch?: typeof fetch;
    headers?: Record<string, string>;
    onMessage?: (event: SSEMessageEvent) => void;
    onError?: (error: Error) => void;
    onOpen?: () => void;
    onClose?: () => void;
    maxRetries?: number;
    retryDelay?: number;
}
export interface SSEMessageEvent {
    data: string;
    type: string;
    id: string | null;
    lastEventId: string;
    origin: string;
}
export interface SSEEvent {
    data: string;
    event: string;
    id: string | null;
}
export declare class SSEClient {
    private url;
    private options;
    private abortController;
    private retryCount;
    private lastEventId;
    private connected;
    constructor(url: string, options?: SSEOptions);
    connect(): Promise<void>;
    private processEventStream;
    private dispatchEvent;
    private handleDisconnect;
    close(): void;
}