/**
 * App command payload definition.
 */
type App = {
    /**
     * The App Store app ID.
     */
    id: string;
    /**
     * Action to perform (e.g., 'write-review').
     */
    action?: string;
};
/**
 * Open an app page in the App Store.
 *
 * @param payload App command payload.
 * @returns App Store app URL.
 * @example
 * app({ id: '836500024' })
 * // => 'itms-apps://itunes.apple.com/app/id836500024'
 * @example
 * app({ id: '836500024', action: 'write-review' })
 * // => 'itms-apps://itunes.apple.com/app/id836500024?action=write-review'
 */
export declare function app(payload: App): string;
export {};