export declare class AvoStreamId {
    private static _anonymousId;
    /**
     * Returns the anonymous ID using Model B (time-window client).
     * Resets when BOTH:
     *   - age > 4 hours (time since creation)
     *   - idle > 2 hours (time since last activity)
     *
     * Returns null if AvoInspector.avoStorage is not initialized (caller
     * should omit streamId so the event is treated as a "wild event").
     */
    static getAnonymousId(): string | null;
    private static storageAvailable;
    private static shouldReset;
    private static createNewId;
    private static updateLastActivity;
    static get streamIdKey(): string;
    static get createdAtKey(): string;
    static get lastActivityKey(): string;
}