/**
 * Twoslash support for code fences that opt in with ```ts twoslash.
 *
 * Twoslash runs the snippet through the TypeScript compiler and annotates it
 * with the real inferred types, which is what makes a hover show `string`
 * rather than a guess. The cost is that it **throws** on anything that does not
 * typecheck: a missing import, a type error, an incomplete fragment.
 *
 * That strictness is the point, but it must not be able to take a whole site
 * down. {@link highlightWithTwoslash} therefore falls back to an ordinary
 * highlight and warns, naming the file, rather than failing the build over one
 * bad snippet.
 *
 * The packages are optional peer dependencies, loaded only when a fence asks
 * for them, so sites that never use Twoslash pay nothing for it.
 */
import type { ShikiTransformer } from 'shiki';
type Loaded = {
    transformer: ShikiTransformer;
} | {
    error: string;
};
export declare function twoslashTransformer(): Promise<Loaded>;
/** One-line reason a snippet could not be annotated, for the build warning. */
export declare function twoslashFailure(error: unknown): string;
export {};