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Output Types

Last updated August 24, 2026

The outputs object contains arrays of build output types:

outputs.pages: React pages from the pages/ directory
outputs.pagesApi: API routes from pages/api/
outputs.appPages: React pages from the app/ directory
outputs.appRoutes: API and metadata routes from app/
outputs.prerenders: ISR-enabled routes and static prerenders
outputs.staticFiles: Static assets and auto-statically optimized pages
outputs.middleware: Middleware function (if present)

Note: When config.output is set to 'export', only outputs.staticFiles is populated. All other arrays (pages, appPages, pagesApi, appRoutes, prerenders) will be empty since the entire application is exported as static files.

For any route output with runtime: 'edge', edgeRuntime is included and contains the canonical entry metadata for invoking that output in your edge runtime. Note that the Edge Runtime is deprecated.

Pages (`outputs.pages`)

React pages from the pages/ directory:

{
  type: 'PAGES'
  id: string           // Route identifier
  filePath: string     // Path to the built file
  pathname: string     // URL pathname
  sourcePage: string   // Original source file path in pages/ directory
  runtime: 'nodejs' | 'edge'
  assets: Record<string, string>  // Traced dependencies (key: relative path from repo root, value: absolute path)
  assetsHashes: Record<string, string>  // Content hashes of each `assets` entry (key: same as `assets`, value: content hash)
  wasmAssets?: Record<string, string>  // Bundled wasm files (key: name, value: absolute path)
  edgeRuntime?: {
    modulePath: string    // Absolute path to the module registered in the edge runtime
    entryKey: string      // Canonical key used by the edge entry registry
    handlerExport: string // Export name to invoke, currently 'handler'
  }
  config: {
    maxDuration?: number  // Maximum duration of the route in seconds
    preferredRegion?: string | string[]  // Preferred deployment region (deprecated)
    env?: Record<string, string>  // Environment variables (edge runtime only)
  }
}

API Routes (`outputs.pagesApi`)

API routes from pages/api/:

{
  type: 'PAGES_API'
  id: string           // Route identifier
  filePath: string     // Path to the built file
  pathname: string     // URL pathname
  sourcePage: string   // Original relative source file path
  runtime: 'nodejs' | 'edge'
  assets: Record<string, string>  // Traced dependencies (key: relative path from repo root, value: absolute path)
  assetsHashes: Record<string, string>  // Content hashes of each `assets` entry (key: same as `assets`, value: content hash)
  wasmAssets?: Record<string, string>  // Bundled wasm files (key: name, value: absolute path)
  edgeRuntime?: {
    modulePath: string    // Absolute path to the module registered in the edge runtime
    entryKey: string      // Canonical key used by the edge entry registry
    handlerExport: string // Export name to invoke, currently 'handler'
  }
  config: {
    maxDuration?: number  // Maximum duration of the route in seconds
    preferredRegion?: string | string[]  // Preferred deployment region (deprecated)
    env?: Record<string, string>  // Environment variables (edge runtime only)
  }
}

App Pages (`outputs.appPages`)

React pages from the app/ directory:

{
  type: 'APP_PAGE'
  id: string           // Route identifier
  filePath: string     // Path to the built file
  pathname: string     // URL pathname. Includes .rsc suffix for RSC routes
  sourcePage: string   // Original relative source file path
  runtime: 'nodejs' | 'edge' // Runtime the route is built for
  assets: Record<string, string>  // Traced dependencies (key: relative path from repo root, value: absolute path)
  assetsHashes: Record<string, string>  // Content hashes of each `assets` entry (key: same as `assets`, value: content hash)
  wasmAssets?: Record<string, string>  // Bundled wasm files (key: name, value: absolute path)
  edgeRuntime?: {
    modulePath: string    // Absolute path to the module registered in the edge runtime
    entryKey: string      // Canonical key used by the edge entry registry
    handlerExport: string // Export name to invoke, currently 'handler'
  }
  config: {
    maxDuration?: number  // Maximum duration of the route in seconds
    preferredRegion?: string | string[]  // Preferred deployment region (deprecated)
    env?: Record<string, string>  // Environment variables (edge runtime only)
  }
}

App Routes (`outputs.appRoutes`)

API and metadata routes from the app/ directory:

{
  type: 'APP_ROUTE'
  id: string           // Route identifier
  filePath: string     // Path to the built file
  pathname: string     // URL pathname
  sourcePage: string   // Original relative source file path
  runtime: 'nodejs' | 'edge' // Runtime the route is built for
  assets: Record<string, string>  // Traced dependencies (key: relative path from repo root, value: absolute path)
  assetsHashes: Record<string, string>  // Content hashes of each `assets` entry (key: same as `assets`, value: content hash)
  wasmAssets?: Record<string, string>  // Bundled wasm files (key: name, value: absolute path)
  edgeRuntime?: {
    modulePath: string    // Absolute path to the module registered in the edge runtime
    entryKey: string      // Canonical key used by the edge entry registry
    handlerExport: string // Export name to invoke, currently 'handler'
  }
  config: {
    maxDuration?: number  // Maximum duration of the route in seconds
    preferredRegion?: string | string[]  // Preferred deployment region (deprecated)
    env?: Record<string, string>  // Environment variables (edge runtime only)
  }
}

Prerenders (`outputs.prerenders`)

ISR-enabled routes and static prerenders:

{
  type: 'PRERENDER'
  id: string           // Route identifier
  pathname: string     // URL pathname
  parentOutputId: string  // ID of the source page/route
  groupId: number        // Revalidation group identifier (prerenders with same groupId revalidate together)
  route: string           // Source route matcher aligned with the filesystem route, keeping dynamic segments (e.g. /blog/[slug] for the prerendered path /blog/first)
  routeType?: 'route' | 'fallback' | 'shell' | 'page'  // Kind of canonical response
  response?: 'empty' | 'initial' | 'complete'  // Completeness before request-time work
  compute?: 'blocking' | 'resuming' | 'static'  // Request-time compute needed for the completed response
  htmlSize?: number       // Byte size of the prerendered App Router HTML shell
  pprChain?: {
    headers: Record<string, string>  // PPR chain headers (e.g., 'next-resume': '1')
  }
  parentFallbackMode?: false | null | string  // false: no additional paths (fallback: false), null: blocking render, string: path to HTML fallback
  fallback?: {
    filePath: string | undefined  // Path to the fallback file (HTML, JSON, or RSC)
    initialStatus?: number  // Initial status code
    initialHeaders?: Record<string, string | string[]>  // Initial headers
    initialExpiration?: number  // Initial expiration time in seconds
    initialRevalidate?: number | false  // Initial revalidate time in seconds, or false for fully static
    postponedState: string | undefined  // Serialized PPR state used for resuming rendering
  }
  config: {
    allowQuery?: string[]     // Allowed query parameters considered for the cache key
    allowHeader?: string[]    // Allowed headers for ISR
    bypassFor?: RouteHas[]    // Cache bypass conditions
    renderingMode?: 'STATIC' | 'PARTIALLY_STATIC'  // STATIC: fully static, PARTIALLY_STATIC: PPR-enabled
    partialFallback?: boolean  // Serves a partial fallback shell that should be upgraded to a full route in the background
    bypassToken?: string      // Generated token that signals the prerender cache should be bypassed
  }
}

Prerender classification

routeType, response, and compute are emitted together on the primary response in a prerender group. Related RSC, data, and segment outputs omit these fields. Pages Router templates with fallback: false also omit them because those templates are never served for unmatched URLs.

routeType identifies the kind of canonical response:

route: a non-UI route, such as a Route Handler
page: a page whose URL has no missing prerenderable parameters
shell: the most specific reusable page shell for its class of URLs
fallback: a reusable page response that can be specialized by filling more prerenderable parameters

response describes how complete the response is before request-time work:

empty: no initial page response can be served
initial: an initial response can be served, but it is not the completed page UI. In practice, this only applies to UI routes that are partially prerenderable
complete: the response is complete; this can include a zero-byte response body, such as a 204 Route Handler response

compute describes the request-time compute needed to serve the completed response:

blocking: no initial response can be sent before request-time compute starts; once started, the response can stream while compute continues
resuming: an initial response is served while postponed work resumes on the server
static: no server compute is required per request

htmlSize is only included on the primary App Router HTML output. A value of 0 means that the HTML shell is empty. Pages Router prerenders, Route Handlers, and related RSC, data, and segment outputs omit it.

Static Files (`outputs.staticFiles`)

Static assets and auto-statically optimized pages:

{
  type: 'STATIC_FILE'
  id: string // Unique identifier for this static file output
  filePath: string // Absolute filesystem path to the built file
  pathname: string // The routable URL pathname for this static file
  immutableHash: string | undefined // Content hash when the filename contains a hash, indicating the file is immutable
}

See Supporting immutable static assets for more information about immutableHash.

Middleware (`outputs.middleware`)

middleware.ts (.js/.ts) or proxy.ts (.js/.ts) function (if present):

{
  type: 'MIDDLEWARE'
  id: string           // Route identifier
  filePath: string     // Path to the built file
  pathname: string      // Always '/_middleware'
  sourcePage: string    // Always 'middleware'
  runtime: 'nodejs' | 'edge' // Runtime the route is built for
  assets: Record<string, string>  // Traced dependencies (key: relative path from repo root, value: absolute path)
  assetsHashes: Record<string, string>  // Content hashes of each `assets` entry (key: same as `assets`, value: content hash)
  wasmAssets?: Record<string, string>  // Bundled wasm files (key: name, value: absolute path)
  edgeRuntime?: {
    modulePath: string    // Absolute path to the module registered in the edge runtime
    entryKey: string      // Canonical key used by the edge entry registry
    handlerExport: string // Export name to invoke, currently 'handler'
  }
  config: {
    maxDuration?: number  // Maximum duration of the route in seconds
    preferredRegion?: string | string[]  // Preferred deployment region (deprecated)
    env?: Record<string, string>  // Environment variables (edge runtime only)
    matchers?: Array<{
      source: string  // Source pattern
      sourceRegex: string  // Compiled regex for matching requests
      has: RouteHas[] | undefined  // Positive matching conditions
      missing: RouteHas[] | undefined  // Negative matching conditions
    }>
  }
}

Output Types

Pages (outputs.pages)

API Routes (outputs.pagesApi)

App Pages (outputs.appPages)

App Routes (outputs.appRoutes)

Prerenders (outputs.prerenders)