import { M as Message } from './message-CyXbT7Zj.cjs';

/**
 * Options passed to a token counter implementation.
 */
interface TokenCounterOptions {
    /** Model identifier — used by provider-specific counters to pick the right tokenizer. */
    model?: string;
}
/**
 * Result returned by a token counter.
 */
interface TokenCountResult {
    /** Total token count across all input messages. */
    total: number;
    /** Per-message breakdown (same order as input). */
    perMessage?: number[];
}
/**
 * Universal token counter contract.
 *
 * Implementations range from zero-dep approximate counters (chars/4) to
 * provider-specific tokenizers (e.g. tiktoken for OpenAI models).
 *
 * @example
 * ```ts
 * const result = await counter.count(messages, { model: 'gpt-4o' })
 * console.log(`Estimated tokens: ${result.total}`)
 * ```
 */
interface TokenCounter {
    /** Human-readable name of the counter (e.g. "approximate", "tiktoken"). */
    readonly name: string;
    /**
     * Count (or estimate) the number of tokens for a list of messages.
     * May be async to allow lazy-loading of tokenizer WASM modules.
     */
    count(messages: ReadonlyArray<Pick<Message, 'role' | 'content'>>, options?: TokenCounterOptions): number | Promise<number>;
    /**
     * Count with per-message breakdown.
     * Falls back to calling `count` once when not overridden.
     */
    countDetailed?(messages: ReadonlyArray<Pick<Message, 'role' | 'content'>>, options?: TokenCounterOptions): TokenCountResult | Promise<TokenCountResult>;
}

export type { TokenCounter as T, TokenCountResult as a, TokenCounterOptions as b };