import { type Usage } from "@velum-labs/routekit-contracts/protocol-ir";
/**
 * Translate Chat Completions token accounting to the Responses vocabulary.
 * Detail objects are copied so compatible current and future counters survive;
 * notably cached_tokens and reasoning_tokens retain their native values.
 */
export declare function chatUsageToResponses(usage: Usage | null | undefined): Record<string, unknown> | null;