export type RoomEvent = {
    app_id: string;
    category: "room.member_joined" | "room.member_left";
    recipients: string[];
    actor_user_id: string;
    title: string;
    body: string;
    coalesced_body?: string;
    collapse_key?: string;
    data?: Record<string, string>;
};
export type NotificationSink = (event: RoomEvent) => Promise<void>;
export declare function announce(sink: NotificationSink | undefined, event: RoomEvent): Promise<void>;
