/**
 * Default error formatter implementation
 * @module hono-ban/formatters/default
 */
import type { BanError, DefaultErrorOutput, Headers } from "../../types";
/**
 * Default JSON formatter with a clean, flat structure
 */
export declare const defaultFormatter: {
    contentType: string;
    /**
     * Format an error into a standardized output structure
     * @param error - Error to format
     * @param headers - Headers for HTTP response (not included in response body)
     * @param sanitize - Fields to remove from output
     * @param includeStackTrace - Whether to include stack traces
     */
    format(error: BanError, headers?: Headers, sanitize?: readonly string[], includeStackTrace?: boolean): DefaultErrorOutput;
};