/**
 * Per-request and process-wide counters for the development render pipeline.
 *
 * @remarks
 * Gated behind {@link isRequestPipelineMetricsEnabled} so production paths stay quiet.
 * Benchmarks and structural invariant tests read the snapshot via
 * {@link getRequestPipelineMetricsSnapshot}.
 */
export type PageModuleLoadOutcome = 'import-cache-hit' | 'disk-cache-hit' | 'cold-build' | 'host-loader' | 'unified-graph';
export type RouteRenderPhase = 'resolve-route-inputs' | 'ownership-validation' | 'resolve-dependencies' | 'page-browser-graph' | 'render-body' | 'transform-response';
export type RouteRenderPhaseRecord = {
    count: number;
    totalDurationMs: number;
    lastDurationMs: number;
};
export type RequestPipelineMetricsSnapshot = {
    runtime: 'node' | 'bun';
    pageModuleLoads: number;
    pageModuleBuilds: number;
    pageModuleCacheHits: number;
    hostLoaderLoads: number;
    diskCacheHits: number;
    routeModuleArtifacts: number;
    mdxTransforms: number;
    collectionBuilds: number;
    routeRenderPhases: Partial<Record<RouteRenderPhase, RouteRenderPhaseRecord>>;
};
export declare function isRequestPipelineMetricsEnabled(): boolean;
export declare function getRequestPipelineMetricsHeaderName(): string;
export declare function resolveRequestPipelineRuntime(): 'node' | 'bun';
export declare function recordPageModuleLoad(outcome: PageModuleLoadOutcome, artifactCount?: number): void;
export declare function recordMdxTransform(): void;
export declare function recordCollectionBuild(): void;
export declare function recordRouteRenderPhase(phase: RouteRenderPhase, durationMs: number): void;
export declare function measureRouteRenderPhase<T>(phase: RouteRenderPhase, fn: () => Promise<T>): Promise<T>;
export declare function getRequestPipelineMetricsSnapshot(): RequestPipelineMetricsSnapshot;
export declare function serializeRequestPipelineMetricsHeader(): string;
export declare function resetRequestPipelineMetrics(): void;