/**
 * Banner renderer — mounts one outbound banner into its own isolated Shadow DOM
 * root (separate from the chat widget's), using plain DOM (no Preact) to stay
 * lightweight. Returns a handle to tear it down.
 */
import type { OutboundCta, OutboundDelivery } from "./types";
export interface BannerHandle {
    destroy(): void;
}
export interface BannerCallbacks {
    onCta(cta: OutboundCta): void;
    onDismiss(): void;
}
/**
 * Render a banner delivery. Removes any existing banner first so only one shows
 * at a time. No-op (returns a dummy handle) outside a browser DOM.
 */
export declare function renderBanner(delivery: OutboundDelivery, callbacks: BannerCallbacks): BannerHandle;
/** Remove any mounted banner without going through a handle (defensive cleanup). */
export declare function removeBanner(): void;