Do not create client reference manifest for metadata route handlers

packages/next/src/build/flying-shuttle/stitch-builds.ts

@@ -31,6 +31,7 @@ import {
 } from '../../shared/lib/constants'
 import { normalizeAppPath } from '../../shared/lib/router/utils/app-paths'
 import type { NextConfigComplete } from '../../server/config-shared'
+import { isMetadataRoute } from '../../lib/metadata/is-metadata-route'
 
 export async function stitchBuilds(
   {
@@ -106,7 +107,7 @@ export async function stitchBuilds(
       path.join(distDir, entryFile + '.nft.json')
     )
 
-    if (type === 'app') {
+    if (type === 'app' && !isMetadataRoute(entry)) {
       const clientRefManifestFile = path.join(
         'server',
         type,

packages/next/src/build/webpack/plugins/flight-manifest-plugin.ts

@@ -26,6 +26,7 @@ import {
 } from '../utils'
 import type { ChunkGroup } from 'webpack'
 import { encodeURIPath } from '../../../shared/lib/encode-uri-path'
+import { isMetadataRoute } from '../../../lib/metadata/is-metadata-route'
 
 interface Options {
   dev: boolean
@@ -519,9 +520,9 @@ export class ClientReferenceManifestPlugin {
         manifestEntryFiles.push(entryName.replace(/\/page(\.[^/]+)?$/, '/page'))
       }
 
-      // We also need to create manifests for route handler entrypoints to
-      // enable `'use cache'`.
-      if (/\/route$/.test(entryName)) {
+      // We also need to create manifests for route handler entrypoints
+      // (excluding metadata route handlers) to enable `'use cache'`.
+      if (/\/route$/.test(entryName) && !isMetadataRoute(entryName)) {
         manifestEntryFiles.push(entryName)
       }
 

packages/next/src/build/webpack/plugins/next-trace-entrypoints-plugin.ts

@@ -23,6 +23,7 @@ import { getModuleBuildInfo } from '../loaders/get-module-build-info'
 import { getPageFilePath } from '../../entries'
 import { resolveExternal } from '../../handle-externals'
 import swcLoader from '../loaders/next-swc-loader'
+import { isMetadataRoute } from '../../../lib/metadata/is-metadata-route'
 
 const PLUGIN_NAME = 'TraceEntryPointsPlugin'
 export const TRACE_IGNORES = [
@@ -277,15 +278,18 @@ export class TraceEntryPointsPlugin implements webpack.WebpackPluginInstance {
         )
 
         if (entrypoint.name.startsWith('app/')) {
-          // include the client reference manifest
-          const clientManifestsForEntrypoint = nodePath.join(
-            outputPath,
-            outputPrefix,
-            entrypoint.name.replace(/%5F/g, '_') +
-              '_' +
-              CLIENT_REFERENCE_MANIFEST +
-              '.js'
-          )
+          // Include the client reference manifest for pages and route handlers,
+          // excluding metadata route handlers.
+          const clientManifestsForEntrypoint = isMetadataRoute(entrypoint.name)
+            ? null
+            : nodePath.join(
+                outputPath,
+                outputPrefix,
+                entrypoint.name.replace(/%5F/g, '_') +
+                  '_' +
+                  CLIENT_REFERENCE_MANIFEST +
+                  '.js'
+              )
 
           if (clientManifestsForEntrypoint !== null) {
             entryFiles.add(clientManifestsForEntrypoint)

packages/next/src/build/webpack/utils.ts

@@ -7,6 +7,7 @@ import type {
   ModuleGraph,
 } from 'webpack'
 import type { ModuleGraphConnection } from 'webpack'
+import { isMetadataRoute } from '../../lib/metadata/is-metadata-route'
 
 export function traverseModules(
   compilation: Compilation,
@@ -47,7 +48,11 @@ export function forEachEntryModule(
 ) {
   for (const [name, entry] of compilation.entries.entries()) {
     // Skip for entries under pages/
-    if (name.startsWith('pages/')) {
+    if (
+      name.startsWith('pages/') ||
+      // Skip for metadata route handlers
+      (name.startsWith('app/') && isMetadataRoute(name))
+    ) {
       continue
     }
 

packages/next/src/server/load-components.ts

@@ -30,6 +30,7 @@ import { wait } from '../lib/wait'
 import { setReferenceManifestsSingleton } from './app-render/encryption-utils'
 import { createServerModuleMap } from './app-render/action-utils'
 import type { DeepReadonly } from '../shared/lib/deep-readonly'
+import { isMetadataRoute } from '../lib/metadata/is-metadata-route'
 
 export type ManifestItem = {
   id: number | string
@@ -139,6 +140,9 @@ async function loadComponentsImpl<N = any>({
     ])
   }
 
+  // Make sure to avoid loading the manifest for metadata route handlers.
+  const hasClientManifest = isAppPath && !isMetadataRoute(page)
+
   // Load the manifest files first
   const [
     buildManifest,
@@ -150,7 +154,7 @@ async function loadComponentsImpl<N = any>({
     loadManifestWithRetries<ReactLoadableManifest>(
       join(distDir, REACT_LOADABLE_MANIFEST)
     ),
-    isAppPath
+    hasClientManifest
       ? loadClientReferenceManifest(
           join(
             distDir,

test/e2e/app-dir/hello-world/hello-world.test.ts

@@ -11,7 +11,7 @@ describe('hello-world', () => {
     expect($('p').text()).toBe('hello world')
   })
 
-  // Recommended for tests that need a full browser
+  // Recommended for tests that need a full browser.
   it('should work using browser', async () => {
     const browser = await next.browser('/')
     expect(await browser.elementByCss('p').text()).toBe('hello world')
@@ -23,7 +23,7 @@ describe('hello-world', () => {
     expect(html).toContain('hello world')
   })
 
-  // In case you need to test the response object
+  // In case you need to test the response object.
   it('should work with fetch', async () => {
     const res = await next.fetch('/')
     const html = await res.text()