export type BrowserDeliveryOptions = {
    batchSize: number;
    flushIntervalMs: number;
};
/** Owns a bounded, in-memory, best-effort delivery queue; it is not a durable outbox. */
export declare class BrowserEventDelivery {
    private readonly target;
    private readonly batchSize;
    private readonly flushIntervalMs;
    private queue;
    private queuedBytes;
    private sendingCount;
    private sendingBytes;
    private timer;
    private inFlight;
    constructor(options: Partial<BrowserDeliveryOptions>, target: {
        enabled: boolean;
        endpoint: string;
        batchPrefix: string;
        headers?: Record<string, string>;
        beacon?: boolean;
    });
    enqueue(event: unknown): boolean;
    flush(): Promise<number>;
    private trim;
    private schedule;
    private drain;
    private send;
}