/**
 * Zoe Middleware — Logging
 *
 * Logs request start and response finish with duration, model, steps, and usage.
 */
import type { Middleware } from "../middleware.js";
export interface LoggingOptions {
    /** Log at request start (default: true) */
    logRequest?: boolean;
    /** Log at response finish (default: true) */
    logResponse?: boolean;
    /** Custom logger (default: console.log) */
    logger?: (message: string) => void;
}
/**
 * Create a logging middleware.
 *
 * @example
 * ```ts
 * const mw = loggingMiddleware({ logRequest: true, logResponse: true });
 * ```
 */
export declare function loggingMiddleware(options?: LoggingOptions): Middleware;