/**
 * Checks whether a string is valid hexadecimal. Supports optional `0x` prefix.
 *
 * @param s - The string to validate.
 * @returns `true` if valid hex.
 */
export declare function isHex(s: string): boolean;
/**
 * Converts a hex string to bytes. Supports optional `0x` prefix.
 *
 * @param hex - The hex string to decode.
 * @throws {@link InvalidHexError} If the string is not valid hex.
 */
export declare function hexToBytes(hex: string): Uint8Array;
/**
 * Converts bytes to a lowercase hex string (without `0x` prefix).
 *
 * @param bytes - The byte array to encode.
 */
export declare function bytesToHex(bytes: Uint8Array): string;
/**
 * Checks whether a string contains only valid Base58 characters.
 *
 * @param s - The string to validate.
 * @returns `true` if valid Base58.
 */
export declare function isBase58(s: string): boolean;