export interface PreviewServer {
    readonly url: string;
    readonly port: number;
    /** Swap the served payload and notify subscribed viewer tabs via SSE. */
    update(payload: ArrayBuffer): void;
    close(): Promise<void>;
}
/**
 * Preview-owned server: serves the built viewer app statically plus two in-memory
 * routes — `/__preview/model` (the current binary payload) and `/__preview/events`
 * (SSE reload pings for `--watch`). Unlike the shared snapshot server there is no
 * `?dir=` dynamic root here, so the filesystem-traversal surface that `/__model/`
 * has to guard never exists on this server. Loopback only.
 */
export declare function startPreviewServer(initial: ArrayBuffer, opts?: {
    port?: number;
}): Promise<PreviewServer>;