/**
 * Token counting utility using tiktoken (cl100k_base encoding)
 *
 * Replaces the rough `Math.ceil(charCount / 4)` heuristic with actual
 * BPE tokenization for accurate context window management.
 */
import type { Message } from '../providers/types.js';
/**
 * Count tokens in a text string using tiktoken.
 * Falls back to chars/4 heuristic for very large or pathologically repetitive strings.
 */
export declare function countTokens(text: string): number;
/**
 * Count tokens across an array of messages
 *
 * Extracts all text content from messages (text blocks, tool inputs/results,
 * thinking blocks) and counts tokens using tiktoken.
 */
export declare function countMessageTokens(messages: Message[]): number;