/**
 * Sanitizes a string by escaping HTML characters to prevent XSS attacks.
 * @param str - The string to sanitize.
 * @returns The sanitized string.
 */
export declare function sanitizeString(str: string): string;
/**
 * Generates a timestamp in ISO 8601 format.
 * @returns The current timestamp as a string.
 */
export declare function getCurrentTimestamp(): string;
/**
 * Sleeps for a given number of milliseconds.
 * @param ms - The number of milliseconds to sleep.
 * @returns A promise that resolves when the sleep is complete.
 *
 * @example
 * ```typescript
 * await sleep(1000);
 * ```
 */
export declare function sleep(ms: number): Promise<void>;
/**
 * Formats a JSON object into a string with indentation.
 * @param json - The JSON object to format.
 * @param replacer - A function that transforms the results.
 * @param space - Adds indentation, white space, and line break characters to the return-value JSON text to make it easier to read.
 * @returns A string representation of the JSON object.
 */
export declare function formatJson(json: object, replacer?: (number | string)[] | null, space?: string | number): string;
/**
 * Formats an error into a standard error object for logging.
 * @param error - The error to format.
 * @returns A standard error object.
 */
export declare function formatError(error: unknown): Error;
/**
 * Executes a function immediately.
 * @param fn - The function to execute.
 * @returns The result of the function.
 *
 * @example
 * ```typescript
 * const result = iife(() => {
 *   return 1 + 1;
 * });
 * console.log(result); // 2
 * ```
 * LangChain <3
 * @see https://github.com/langchain-ai/langchainjs/blob/981cf9c480925187a524fd6ad1dbf0488d2758eb/libs/langchain-core/src/language_models/utils.ts#L5
 */
export declare const iife: <T>(fn: () => T) => T;
export declare function encodeBase64(data: string): string;
export declare function decodeBase64(data: string): string;