/**
 * Token Tracker — Per-session usage tracking and cost estimation.
 */
import type { TokenUsage, ModelTier } from "./types.js";
export declare class TokenTracker {
    private entries;
    record(usage: TokenUsage, tier: ModelTier, model: string): void;
    get totalInput(): number;
    get totalOutput(): number;
    get totalCost(): number;
    get callCount(): number;
    get summary(): string;
    persist(projectRoot: string): Promise<void>;
}