/**
 * Marks a class as a tRPC router.
 *
 * The class will be scanned for `@Query()`, `@Mutation()`, and `@Subscription()` methods,
 * which become tRPC procedures on the merged router.
 *
 * @param alias - Optional prefix that nests all procedures under a sub-router.
 *
 * @publicApi
 */
export declare function Router(alias?: string): ClassDecorator;