code · pull · Jun 3, 2026 · Jun 2, 2026 · Jun 2, 2026 · Jun 2, 2026
diff --git a/.github/workflows/build_and_test.yml b/.github/workflows/build_and_test.yml
@@ -1013,134 +1013,6 @@ jobs:
       stepName: 'test-cache-components-prod-${{ matrix.group }}'
     secrets: inherit
 
-  test-node-streams-cache-components-dev:
-    name: test node streams cache components dev
-    needs:
-      [
-        'optimize-ci',
-        'changes',
-        'build-native',
-        'build-next',
-        'fetch-test-timings',
-      ]
-    if: ${{ needs.optimize-ci.outputs.skip == 'false' && needs.changes.outputs.docs-only == 'false' }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        group: [1/6, 2/6, 3/6, 4/6, 5/6, 6/6]
-    uses: ./.github/workflows/build_reusable.yml
-    with:
-      afterBuild: |
-        export __NEXT_USE_NODE_STREAMS=true
-        export __NEXT_CACHE_COMPONENTS=true
-        export __NEXT_EXPERIMENTAL_CACHED_NAVIGATIONS=true
-        export __NEXT_EXPERIMENTAL_APP_NEW_SCROLL_HANDLER=true
-        export NEXT_EXTERNAL_TESTS_FILTERS="test/cache-components-tests-manifest.json"
-        export NEXT_TEST_MODE=dev
-        export IS_TURBOPACK_TEST=1
-        export TURBOPACK_DEV=1
-
-        node run-tests.js \
-          --timings \
-          --require-timings \
-          -g ${{ matrix.group }} \
-          --type development
-      testTimingsArtifact: 'test-timings'
-      stepName: 'test-node-streams-cache-components-dev-${{ matrix.group }}'
-    secrets: inherit
-
-  test-node-streams-cache-components-prod:
-    name: test node streams cache components prod
-    needs:
-      [
-        'optimize-ci',
-        'changes',
-        'build-native',
-        'build-next',
-        'fetch-test-timings',
-      ]
-    if: ${{ needs.optimize-ci.outputs.skip == 'false' && needs.changes.outputs.docs-only == 'false' }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        group: [1/7, 2/7, 3/7, 4/7, 5/7, 6/7, 7/7]
-    uses: ./.github/workflows/build_reusable.yml
-    with:
-      afterBuild: |
-        export __NEXT_USE_NODE_STREAMS=true
-        export __NEXT_CACHE_COMPONENTS=true
-        export __NEXT_EXPERIMENTAL_CACHED_NAVIGATIONS=true
-        export __NEXT_EXPERIMENTAL_APP_NEW_SCROLL_HANDLER=true
-        export NEXT_EXTERNAL_TESTS_FILTERS="test/cache-components-tests-manifest.json"
-        export NEXT_TEST_MODE=start
-        export IS_TURBOPACK_TEST=1
-        export TURBOPACK_BUILD=1
-
-        node run-tests.js \
-          --timings \
-          --require-timings \
-          -g ${{ matrix.group }} \
-          --type production
-      testTimingsArtifact: 'test-timings'
-      stepName: 'test-node-streams-cache-components-prod-${{ matrix.group }}'
-    secrets: inherit
-
-  test-node-streams-dev:
-    name: test node streams dev
-    needs: ['optimize-ci', 'changes', 'build-native', 'build-next']
-    if: ${{ needs.optimize-ci.outputs.skip == 'false' && needs.changes.outputs.docs-only == 'false' }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        group: [1/6, 2/6, 3/6, 4/6, 5/6, 6/6]
-    uses: ./.github/workflows/build_reusable.yml
-    with:
-      afterBuild: |
-        export __NEXT_USE_NODE_STREAMS=true
-        export NEXT_EXTERNAL_TESTS_FILTERS="test/cache-components-tests-manifest.json,test/use-node-streams-tests-manifest.json"
-        export NEXT_TEST_MODE=dev
-        export IS_TURBOPACK_TEST=1
-        export TURBOPACK_DEV=1
-        export __NEXT_EXPERIMENTAL_STRICT_ROUTE_TYPES=true
-        export RUST_BACKTRACE=1
-
-        node run-tests.js \
-          --timings \
-          -g ${{ matrix.group }} \
-          --type development
-      stepName: 'test-node-streams-dev-${{ matrix.group }}'
-    secrets: inherit
-
-  test-node-streams-prod:
-    name: test node streams prod
-    needs: ['optimize-ci', 'changes', 'build-native', 'build-next']
-    if: ${{ needs.optimize-ci.outputs.skip == 'false' && needs.changes.outputs.docs-only == 'false' }}
-
-    strategy:
-      fail-fast: false
-      matrix:
-        group: [1/7, 2/7, 3/7, 4/7, 5/7, 6/7, 7/7]
-    uses: ./.github/workflows/build_reusable.yml
-    with:
-      afterBuild: |
-        export __NEXT_USE_NODE_STREAMS=true
-        export NEXT_EXTERNAL_TESTS_FILTERS="test/cache-components-tests-manifest.json,test/use-node-streams-tests-manifest.json"
-        export NEXT_TEST_MODE=start
-        export IS_TURBOPACK_TEST=1
-        export TURBOPACK_BUILD=1
-        export __NEXT_EXPERIMENTAL_STRICT_ROUTE_TYPES=true
-        export RUST_BACKTRACE=1
-
-        node run-tests.js \
-          --timings \
-          -g ${{ matrix.group }} \
-          --type production
-      stepName: 'test-node-streams-prod-${{ matrix.group }}'
-    secrets: inherit
-
   tests-pass:
     needs:
       [
@@ -1157,10 +1029,6 @@ jobs:
         'test-firefox-safari',
         'test-cache-components-dev',
         'test-cache-components-prod',
-        'test-node-streams-cache-components-dev',
-        'test-node-streams-cache-components-prod',
-        'test-node-streams-dev',
-        'test-node-streams-prod',
         'test-cargo-unit',
         'rust-check',
         'rustdoc-check',

diff --git a/lerna.json b/lerna.json
@@ -15,5 +15,5 @@
       "registry": "https://registry.npmjs.org/"
     }
   },
-  "version": "16.3.0-canary.37"
+  "version": "16.3.0-canary.38"
 }
diff --git a/packages/create-next-app/package.json b/packages/create-next-app/package.json
@@ -1,6 +1,6 @@
 {
   "name": "create-next-app",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "keywords": [
     "react",
     "next",

diff --git a/packages/eslint-config-next/package.json b/packages/eslint-config-next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "eslint-config-next",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "ESLint configuration used by Next.js.",
   "license": "MIT",
   "repository": {
@@ -12,7 +12,7 @@
     "dist"
   ],
   "dependencies": {
-    "@next/eslint-plugin-next": "16.3.0-canary.37",
+    "@next/eslint-plugin-next": "16.3.0-canary.38",
     "eslint-import-resolver-node": "^0.3.6",
     "eslint-import-resolver-typescript": "^3.5.2",
     "eslint-plugin-import": "^2.32.0",

diff --git a/packages/eslint-plugin-internal/package.json b/packages/eslint-plugin-internal/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@next/eslint-plugin-internal",
   "private": true,
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "ESLint plugin for working on Next.js.",
   "exports": {
     ".": "./src/eslint-plugin-internal.js"

diff --git a/packages/eslint-plugin-next/package.json b/packages/eslint-plugin-next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/eslint-plugin-next",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "ESLint plugin for Next.js.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

diff --git a/packages/font/package.json b/packages/font/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@next/font",
   "private": true,
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/font"

diff --git a/packages/next-bundle-analyzer/package.json b/packages/next-bundle-analyzer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/bundle-analyzer",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "main": "index.js",
   "types": "index.d.ts",
   "license": "MIT",

diff --git a/packages/next-codemod/package.json b/packages/next-codemod/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/codemod",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "license": "MIT",
   "repository": {
     "type": "git",

diff --git a/packages/next-env/index.ts b/packages/next-env/index.ts
@@ -18,7 +18,17 @@ let cachedLoadedEnvFiles: LoadedEnvFiles = []
 let previousLoadedEnvFiles: LoadedEnvFiles = []
 
 export function updateInitialEnv(newEnv: Env) {
-  Object.assign(initialEnv || {}, newEnv)
+  if (!initialEnv) {
+    return
+  }
+
+  for (const [key, value] of Object.entries(newEnv)) {
+    if (value === undefined) {
+      delete initialEnv[key]
+    } else {
+      initialEnv[key] = value
+    }
+  }
 }
 
 type Log = {

diff --git a/packages/next-env/package.json b/packages/next-env/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/env",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "keywords": [
     "react",
     "next",

diff --git a/packages/next-mdx/package.json b/packages/next-mdx/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/mdx",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "main": "index.js",
   "license": "MIT",
   "repository": {

diff --git a/packages/next-playwright/package.json b/packages/next-playwright/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/playwright",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/next-playwright"

diff --git a/packages/next-plugin-storybook/package.json b/packages/next-plugin-storybook/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/plugin-storybook",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/next-plugin-storybook"

diff --git a/packages/next-polyfill-module/package.json b/packages/next-polyfill-module/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/polyfill-module",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "A standard library polyfill for ES Modules supporting browsers (Edge 16+, Firefox 60+, Chrome 61+, Safari 10.1+)",
   "main": "dist/polyfill-module.js",
   "license": "MIT",

diff --git a/packages/next-polyfill-nomodule/package.json b/packages/next-polyfill-nomodule/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/polyfill-nomodule",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "A polyfill for non-dead, nomodule browsers.",
   "main": "dist/polyfill-nomodule.js",
   "license": "MIT",

diff --git a/packages/next-routing/package.json b/packages/next-routing/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/routing",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "keywords": [
     "react",
     "next",

diff --git a/packages/next-rspack/package.json b/packages/next-rspack/package.json
@@ -1,6 +1,6 @@
 {
   "name": "next-rspack",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/next-rspack"

diff --git a/packages/next-swc/package.json b/packages/next-swc/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@next/swc",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "private": true,
   "files": [
     "native/"

diff --git a/packages/next/package.json b/packages/next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "next",
-  "version": "16.3.0-canary.37",
+  "version": "16.3.0-canary.38",
   "description": "The React Framework",
   "main": "./dist/server/next.js",
   "license": "MIT",
@@ -101,7 +101,7 @@
     ]
   },
   "dependencies": {
-    "@next/env": "16.3.0-canary.37",
+    "@next/env": "16.3.0-canary.38",
     "@swc/helpers": "0.5.15",
     "baseline-browser-mapping": "^2.9.19",
     "caniuse-lite": "^1.0.30001579",
@@ -165,11 +165,11 @@
     "@modelcontextprotocol/sdk": "1.18.1",
     "@mswjs/interceptors": "0.23.0",
     "@napi-rs/triples": "1.2.0",
-    "@next/font": "16.3.0-canary.37",
-    "@next/polyfill-module": "16.3.0-canary.37",
-    "@next/polyfill-nomodule": "16.3.0-canary.37",
-    "@next/react-refresh-utils": "16.3.0-canary.37",
-    "@next/swc": "16.3.0-canary.37",
+    "@next/font": "16.3.0-canary.38",
+    "@next/polyfill-module": "16.3.0-canary.38",
+    "@next/polyfill-nomodule": "16.3.0-canary.38",
+    "@next/react-refresh-utils": "16.3.0-canary.38",
+    "@next/swc": "16.3.0-canary.38",
     "@opentelemetry/api": "1.6.0",
     "@playwright/test": "1.58.2",
     "@rspack/core": "1.6.7",

diff --git a/packages/next/src/server/app-render/stream-ops.node.ts b/packages/next/src/server/app-render/stream-ops.node.ts
@@ -614,9 +614,6 @@ export async function renderToNodeFizzStream(
       onHeaders: streamOptions?.onHeaders,
       onShellReady() {
         streamOptions?.onShellReady?.()
-        if (!deferPipe) {
-          pipeable.pipe(pt)
-        }
         shellReady.resolve()
       },
       onShellError(error: unknown) {
@@ -636,6 +633,11 @@ export async function renderToNodeFizzStream(
 
   await shellReady.promise
 
+  if (!deferPipe) {
+    await waitAtLeastOneReactRenderTask()
+    pipeable.pipe(pt)
+  }
+
   return {
     stream: pt,
     allReady: allReady.promise,

diff --git a/packages/next/src/server/config-shared.ts b/packages/next/src/server/config-shared.ts
@@ -36,7 +36,7 @@ export type NextConfigComplete = Required<Omit<NextConfig, 'configFile'>> & {
     prefetchInlining?: PrefetchInliningConfig
     // Normalized by config.ts: defaulted to 90% of staticPageGenerationTimeout
     useCacheTimeout: number
-    // Normalized by config.ts `finalizeConfig`: defaulted to `'manual-warning'`
+    // Normalized by config.ts `finalizeConfig`: defaulted to `'warning'`
     instantInsights: { validationLevel: ValidationLevel }
   }
   // The root directory of the distDir. In development mode, this is the parent directory of `distDir`
@@ -1080,10 +1080,10 @@ export interface ExperimentalConfig {
     /**
      * Controls the validation behavior of Instant Insights
      *
-     * - `'warning'`: Validates all navigations for Instant UI in development
-     * - `'manual-warning'`: Validates navigations for Instant UI in development when configured with `unstable_instant` in Pages and Layouts
+     * - `'warning'` (default): Validates all navigations for Instant UI in development
+     * - `'manual-warning'`: Validates navigations for Instant UI in development only when configured with `unstable_instant` in Pages and Layouts
      * - `'experimental-error'`: Validates all navigations for Instant in development and build. Use with caution.
-     * - `'experimental-manual-error'`: Validates navigations for Instant UI in developement and build when configured with `unstable_instant` in Pages and Layouts. Use with caution.
+     * - `'experimental-manual-error'`: Validates navigations for Instant UI in development and build when configured with `unstable_instant` in Pages and Layouts. Use with caution.
      */
     validationLevel?: ValidationLevel
   }
@@ -2040,6 +2040,7 @@ export const defaultConfig = Object.freeze({
     gestureTransition: false,
     inlineCss: false,
     useCache: undefined,
+    useNodeStreams: true,
     slowModuleDetection: undefined,
     globalNotFound: false,
     browserDebugInfoInTerminal: 'warn',