/**
 * Convert data to TOON format with JSON fallback.
 *
 * TOON (Token-Oriented Object Notation) is 30-60% more token-efficient than JSON
 * for tabular data, making it ideal for LLM responses.
 *
 * @param data - The data to convert
 * @param jsonFallback - JSON string to return if TOON encoding fails
 * @returns TOON formatted string, or JSON fallback on failure
 *
 * @example
 * const json = JSON.stringify(data, null, 2);
 * const output = await toToonOrJson(data, json);
 */
export declare function toToonOrJson(data: unknown, jsonFallback: string): Promise<string>;
/**
 * Synchronous TOON conversion with JSON fallback.
 *
 * Uses cached encoder if available, otherwise returns JSON fallback.
 * Prefer toToonOrJson for first-time conversion.
 *
 * @param data - The data to convert
 * @param jsonFallback - The JSON string to return if TOON is unavailable
 * @returns TOON formatted string, or JSON fallback
 */
export declare function toToonOrJsonSync(data: unknown, jsonFallback: string): string;
/**
 * Pre-load the TOON encoder for synchronous usage later.
 * Call this during server initialization.
 */
export declare function preloadToonEncoder(): Promise<boolean>;