export interface TimingEntry {
    name: string;
    start?: number;
    duration?: number;
    description?: string;
}
export declare class ServerTimingContext {
    private entries;
    private requestStart;
    constructor();
    /** Start a named timer */
    start(name: string): void;
    /** End a named timer */
    end(name: string): void;
    /** Add a metric with a known duration */
    add(name: string, duration: number, description?: string): void;
    /** Get total request duration */
    get totalDuration(): number;
    /** Build the Server-Timing header value */
    toHeader(): string;
}
/**
 * Server Timing middleware — tracks request timing and adds Server-Timing header.
 *
 * @example
 * router.useRouter([serverTiming()])
 *
 * // In handler:
 * async show(ctx) {
 *   ctx.timing.start('db')
 *   const user = await User.find(1)
 *   ctx.timing.end('db')
 *   return user
 * }
 *
 * // Browser DevTools shows:
 * // total: 12.5ms, db: 8.2ms
 */
export declare function serverTiming(): (ctx: any, next: () => Promise<void>) => Promise<void>;
declare module './types' {
    interface HttpContext {
        timing: {
            start: (name: string) => void;
            end: (name: string) => void;
            add: (name: string, duration: number, description?: string) => void;
        };
    }
}