code · pull · May 8, 2026 · May 7, 2026 · May 7, 2026 · May 7, 2026
diff --git a/.github/workflows/graphite_ci_optimizer.yml b/.github/workflows/graphite_ci_optimizer.yml
@@ -36,10 +36,14 @@ jobs:
     name: Graphite CI Optimizer
     runs-on: ubuntu-latest
     outputs:
+      # `== 'true'` comparison: If `step.check-skip` fails (`continue-on-error`), that output will
+      # be an empty string, which sets our `skip` output to `'false'`.
       skip: ${{ env.HAS_BYPASS_LABEL == 'false' && steps.check-skip.outputs.skip == 'true' }}
     steps:
       - name: Optimize CI
         id: check-skip
+        # Graphite's action is designed to fail open, but still sometimes fails if GH's infra flakes
+        continue-on-error: true
         uses: withgraphite/graphite-ci-action@ee395f3a78254c006d11339669c6cabddf196f72 # main
         with:
           graphite_token: ${{ secrets.GRAPHITE_TOKEN }}

diff --git a/...pi-reference/04-functions/unstable_io.mdx → ...-app/03-api-reference/04-functions/io.mdx b/...pi-reference/04-functions/unstable_io.mdx → ...-app/03-api-reference/04-functions/io.mdx
@@ -1,22 +1,22 @@
 ---
-title: unstable_io
-description: API Reference for the unstable_io function.
+title: io
+description: API Reference for the io function.
 version: draft
 ---
 
-`unstable_io()` informs Next.js that an IO operation will follow this call. When [Cache Components](/docs/app/api-reference/config/next-config-js/cacheComponents) is not enabled or when rendering in Pages Router, signifying IO in this way is not meaningful and the call will always resolve immediately. When Cache Components is enabled, you may be required to add `await unstable_io()` preceding synchronous IO that is encountered while prerendering pages (`new Date()` for example). Additionally, if you want to avoid having genuine uncached IO invoked while prerendering, you shield it by preceeding it with `await unstable_io()`.
+`io()` informs Next.js that an IO operation will follow this call. When [Cache Components](/docs/app/api-reference/config/next-config-js/cacheComponents) is not enabled or when rendering in Pages Router, signifying IO in this way is not meaningful and the call will always resolve immediately. When Cache Components is enabled, you may be required to add `await io()` preceding synchronous IO that is encountered while prerendering pages (`new Date()` for example). Additionally, if you want to avoid having genuine uncached IO invoked while prerendering, you shield it by preceeding it with `await io()`.
 
 ```ts filename="app/page.tsx" switcher
-import { unstable_io } from 'next/cache'
+import { io } from 'next/cache'
 import { db } from '@/lib/db'
 
 export default async function Page() {
   // Synchronous IO: new Date() would fail during prerender without this
-  await unstable_io()
+  await io()
   const now = new Date().toISOString()
 
   // Async IO: the query would run and be discarded during prerender;
-  // unstable_io() above lets Next.js skip it entirely
+  // io() above lets Next.js skip it entirely
   const orders = await db.query('SELECT * FROM orders LIMIT 10')
 
   return (
@@ -33,16 +33,16 @@ export default async function Page() {
 ```
 
 ```js filename="app/page.js" switcher
-import { unstable_io } from 'next/cache'
+import { io } from 'next/cache'
 import { db } from '@/lib/db'
 
 export default async function Page() {
   // Synchronous IO: new Date() would fail during prerender without this
-  await unstable_io()
+  await io()
   const now = new Date().toISOString()
 
   // Async IO: the query would run and be discarded during prerender;
-  // unstable_io() above lets Next.js skip it entirely
+  // io() above lets Next.js skip it entirely
   const orders = await db.query('SELECT * FROM orders LIMIT 10')
 
   return (
@@ -62,16 +62,16 @@ export default async function Page() {
 
 [`connection()`](/docs/app/api-reference/functions/connection) requires an active HTTP request context and signals that the component needs request-specific data. It is imported from `next/server`.
 
-`unstable_io()` does not require a request context. It can be used inside `"use cache"` scopes, client components, and anywhere you perform IO that should not be included in a static prerender. It is imported from `next/cache`.
+`io()` does not require a request context. It can be used inside `"use cache"` scopes, client components, and anywhere you perform IO that should not be included in a static prerender. It is imported from `next/cache`.
 
-Use `connection()` when you need the request itself (cookies, headers, etc.). Use `unstable_io()` when you perform IO that is independent of the request but should still prevent static prerendering.
+Use `connection()` when you need the request itself (cookies, headers, etc.). Use `io()` when you perform IO that is independent of the request but should still prevent static prerendering.
 
 ## Reference
 
 ### Type
 
 ```ts
-function unstable_io(): Promise<void>
+function io(): Promise<void>
 ```
 
 ### Parameters
@@ -84,12 +84,12 @@ function unstable_io(): Promise<void>
 
 ## Good to know
 
-- `unstable_io()` is imported from `next/cache`, not `next/server`.
-- Inside `"use cache"` scopes, `unstable_io()` resolves immediately. The cache captures the IO result at fill time.
-- In client components, `unstable_io()` resolves immediately since there is no prerender context in the browser.
+- `io()` is imported from `next/cache`, not `next/server`.
+- Inside `"use cache"` scopes, `io()` resolves immediately. The cache captures the IO result at fill time.
+- In client components, `io()` resolves immediately since there is no prerender context in the browser.
 
 ### Version History
 
-| Version   | Changes              |
-| --------- | -------------------- |
-| `v16.x.x` | `unstable_io` added. |
+| Version   | Changes     |
+| --------- | ----------- |
+| `v16.x.x` | `io` added. |
diff --git a/lerna.json b/lerna.json
@@ -15,5 +15,5 @@
       "registry": "https://registry.npmjs.org/"
     }
   },
-  "version": "16.3.0-canary.14"
+  "version": "16.3.0-canary.16"
 }
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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "description": "ESLint configuration used by Next.js.",
   "license": "MIT",
   "repository": {
@@ -12,7 +12,7 @@
     "dist"
   ],
   "dependencies": {
-    "@next/eslint-plugin-next": "16.3.0-canary.14",
+    "@next/eslint-plugin-next": "16.3.0-canary.16",
     "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "license": "MIT",
   "repository": {
     "type": "git",

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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "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.14",
+  "version": "16.3.0-canary.16",
   "private": true,
   "files": [
     "native/"

diff --git a/packages/next/cache.d.ts b/packages/next/cache.d.ts
@@ -9,7 +9,7 @@ export {
 
 export { unstable_noStore } from 'next/dist/server/web/spec-extension/unstable-no-store'
 
-export { unstable_io } from 'next/dist/server/request/io'
+export { io } from 'next/dist/server/request/io'
 
 import { cacheTag } from 'next/dist/server/use-cache/cache-tag'
 

diff --git a/packages/next/cache.js b/packages/next/cache.js
@@ -17,7 +17,7 @@ if (process.env.NEXT_RUNTIME === '') {
       }
     },
     unstable_noStore: function unstable_noStore() {},
-    unstable_io: require('next/dist/client/request/io.browser').unstable_io,
+    io: require('next/dist/client/request/io.browser').io,
 
     updateTag: notAvailableInClient('updateTag'),
     revalidateTag: notAvailableInClient('revalidateTag'),
@@ -46,7 +46,7 @@ if (process.env.NEXT_RUNTIME === '') {
     unstable_noStore:
       require('next/dist/server/web/spec-extension/unstable-no-store')
         .unstable_noStore,
-    unstable_io: require('next/dist/server/request/io').unstable_io,
+    io: require('next/dist/server/request/io').io,
     cacheLife: require('next/dist/server/use-cache/cache-life').cacheLife,
     cacheTag: require('next/dist/server/use-cache/cache-tag').cacheTag,
   }
@@ -94,4 +94,4 @@ exports.unstable_cacheLife = cacheExports.unstable_cacheLife
 exports.cacheTag = cacheExports.cacheTag
 exports.unstable_cacheTag = cacheExports.unstable_cacheTag
 exports.refresh = cacheExports.refresh
-exports.unstable_io = cacheExports.unstable_io
+exports.io = cacheExports.io
diff --git a/packages/next/package.json b/packages/next/package.json
@@ -1,6 +1,6 @@
 {
   "name": "next",
-  "version": "16.3.0-canary.14",
+  "version": "16.3.0-canary.16",
   "description": "The React Framework",
   "main": "./dist/server/next.js",
   "license": "MIT",
@@ -101,7 +101,7 @@
     ]
   },
   "dependencies": {
-    "@next/env": "16.3.0-canary.14",
+    "@next/env": "16.3.0-canary.16",
     "@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.14",
-    "@next/polyfill-module": "16.3.0-canary.14",
-    "@next/polyfill-nomodule": "16.3.0-canary.14",
-    "@next/react-refresh-utils": "16.3.0-canary.14",
-    "@next/swc": "16.3.0-canary.14",
+    "@next/font": "16.3.0-canary.16",
+    "@next/polyfill-module": "16.3.0-canary.16",
+    "@next/polyfill-nomodule": "16.3.0-canary.16",
+    "@next/react-refresh-utils": "16.3.0-canary.16",
+    "@next/swc": "16.3.0-canary.16",
     "@opentelemetry/api": "1.6.0",
     "@playwright/test": "1.58.2",
     "@rspack/core": "1.6.7",

diff --git a/packages/next/src/build/templates/app-page.ts b/packages/next/src/build/templates/app-page.ts
@@ -29,6 +29,7 @@ import {
   NodeNextResponse,
 } from '../../server/base-http/node' with { 'turbopack-transition': 'next-server-utility' }
 import { checkIsAppPPREnabled } from '../../server/lib/experimental/ppr' with { 'turbopack-transition': 'next-server-utility' }
+import { isRSCRequestHeader } from '../../server/lib/is-rsc-request' with { 'turbopack-transition': 'next-server-utility' }
 import {
   getFallbackRouteParams,
   getPlaceholderFallbackRouteParams,
@@ -294,7 +295,8 @@ export async function handler(
   // NOTE: Don't delete headers[RSC] yet, it still needs to be used in renderToHTML later
 
   const isRSCRequest =
-    getRequestMeta(req, 'isRSCRequest') ?? Boolean(req.headers[RSC_HEADER])
+    getRequestMeta(req, 'isRSCRequest') ??
+    isRSCRequestHeader(req.headers[RSC_HEADER])
 
   const isPossibleServerAction = getIsPossibleServerAction(req)
 
@@ -426,7 +428,7 @@ export async function handler(
   const isInstantNavigationTest =
     exposeTestingApi &&
     (req.headers[NEXT_INSTANT_PREFETCH_HEADER] === '1' ||
-      (req.headers[RSC_HEADER] === undefined &&
+      (!isRSCRequestHeader(req.headers[RSC_HEADER]) &&
         typeof req.headers.cookie === 'string' &&
         req.headers.cookie.includes(NEXT_INSTANT_TEST_COOKIE + '=')))
 

diff --git a/packages/next/src/client/request/io.browser.ts b/packages/next/src/client/request/io.browser.ts
@@ -5,9 +5,9 @@ const resolvedIOPromise: Promise<void> = Promise.resolve(undefined)
 ;(resolvedIOPromise as any).value = undefined
 
 /**
- * Browser implementation of unstable_io(). On the client there is no
+ * Browser implementation of io(). On the client there is no
  * prerender context so we always resolve immediately.
  */
-export function unstable_io(): Promise<void> {
+export function io(): Promise<void> {
   return resolvedIOPromise
 }
diff --git a/packages/next/src/client/script.tsx b/packages/next/src/client/script.tsx
@@ -6,6 +6,7 @@ import type { ScriptHTMLAttributes } from 'react'
 import { HeadManagerContext } from '../shared/lib/head-manager-context.shared-runtime'
 import { setAttributesFromProps } from './set-attributes-from-props'
 import { requestIdleCallback } from './request-idle-callback'
+import { htmlEscapeJsonString } from '../shared/lib/htmlescape'
 
 const ScriptCache = new Map()
 const LoadCache = new Set()
@@ -327,10 +328,9 @@ function Script(props: ScriptProps): JSX.Element | null {
           <script
             nonce={nonce}
             dangerouslySetInnerHTML={{
-              __html: `(self.__next_s=self.__next_s||[]).push(${JSON.stringify([
-                0,
-                { ...restProps, id },
-              ])})`,
+              __html: `(self.__next_s=self.__next_s||[]).push(${htmlEscapeJsonString(
+                JSON.stringify([0, { ...restProps, id }])
+              )})`,
             }}
           />
         )
@@ -351,10 +351,9 @@ function Script(props: ScriptProps): JSX.Element | null {
           <script
             nonce={nonce}
             dangerouslySetInnerHTML={{
-              __html: `(self.__next_s=self.__next_s||[]).push(${JSON.stringify([
-                src,
-                { ...restProps, id },
-              ])})`,
+              __html: `(self.__next_s=self.__next_s||[]).push(${htmlEscapeJsonString(
+                JSON.stringify([src, { ...restProps, id }])
+              )})`,
             }}
           />
         )