/**
 * Tracks API usage metrics for LLM requests.
 */
export declare class Usage {
    /**
     * Total requests made to the LLM API.
     */
    requests: number;
    /**
     * Total input tokens sent, across all requests.
     */
    input_tokens: number;
    /**
     * Total output tokens received, across all requests.
     */
    output_tokens: number;
    /**
     * Total tokens sent and received, across all requests.
     */
    total_tokens: number;
    constructor({ requests, input_tokens, output_tokens, total_tokens, }?: {
        requests?: number;
        input_tokens?: number;
        output_tokens?: number;
        total_tokens?: number;
    });
    /**
     * Adds usage statistics from another Usage object to this one.
     * @param other The Usage object to add.
     */
    add(other: Usage): void;
}