import type { UsageStats } from '@mastra/core/observability';
/**
 * LangSmithUsageMetrics
 *
 * Canonical metric keys expected by LangSmith for LLM usage accounting.
 * See: https://docs.langchain.com/langsmith/log-llm-trace#provide-token-and-cost-information
 */
export interface LangSmithUsageMetrics {
    input_tokens?: number;
    output_tokens?: number;
    total_tokens?: number;
    input_token_details?: {
        [key: string]: number;
    };
    output_token_details?: {
        [key: string]: number;
    };
}
/**
 * Formats UsageStats to LangSmith's expected metric format.
 */
export declare function formatUsageMetrics(usage?: UsageStats): LangSmithUsageMetrics;
//# sourceMappingURL=metrics.d.ts.map