/**
 * Cost Tracker - Track token usage and costs across LLM requests
 */
export interface ModelPricing {
    inputCostPer1k: number;
    outputCostPer1k: number;
}
export interface TokenUsage {
    inputTokens: number;
    outputTokens: number;
    totalTokens: number;
}
export interface RequestStats {
    timestamp: number;
    model: string;
    usage: TokenUsage;
    cost: number;
    latencyMs?: number;
}
export interface SessionStats {
    totalInputTokens: number;
    totalOutputTokens: number;
    totalTokens: number;
    totalCost: number;
    requestCount: number;
    avgLatencyMs: number;
    startTime: number;
    requests: RequestStats[];
}
/**
 * Model pricing data (USD per 1K tokens)
 */
export declare const MODEL_PRICING: Record<string, ModelPricing>;
/**
 * Cost Tracker class
 */
export declare class CostTracker {
    private stats;
    private customPricing;
    constructor();
    private createEmptyStats;
    /**
     * Add a request's token usage
     */
    addUsage(model: string, inputTokens: number, outputTokens: number, latencyMs?: number): RequestStats;
    /**
     * Calculate cost for token usage
     */
    calculateCost(model: string, inputTokens: number, outputTokens: number): number;
    /**
     * Get pricing for a model
     */
    getPricing(model: string): ModelPricing;
    /**
     * Set custom pricing for a model
     */
    setCustomPricing(model: string, pricing: ModelPricing): void;
    /**
     * Get current session stats
     */
    getStats(): SessionStats;
    /**
     * Get summary string
     */
    getSummary(): string;
    /**
     * Get detailed breakdown by model
     */
    getBreakdownByModel(): Record<string, {
        tokens: number;
        cost: number;
        requests: number;
    }>;
    /**
     * Reset stats
     */
    reset(): void;
    /**
     * Export stats to JSON
     */
    toJSON(): SessionStats;
    /**
     * Import stats from JSON
     */
    fromJSON(data: SessionStats): void;
    get totalTokens(): number;
    get totalCost(): number;
    get requests(): number;
}
/**
 * Create a cost tracker instance
 */
export declare function createCostTracker(): CostTracker;
/**
 * Estimate tokens from text (rough approximation)
 */
export declare function estimateTokens(text: string): number;
/**
 * Format cost as currency string
 */
export declare function formatCost(cost: number): string;