[pull] canary from vercel:canary

docs/01-app/03-api-reference/04-functions/unstable_cache.mdx

@@ -26,9 +26,22 @@ export default async function Component({ userID }) {
 
 > **Good to know**:
 >
-> - Accessing uncached data sources such as `headers` or `cookies` inside a cache scope is not supported. If you need this data inside a cached function use `headers` outside of the cached function and pass the required uncached data in as an argument.
+> - Accessing request data such as `headers` or `cookies` inside a cache scope is not supported. Read the data outside the cached function and pass the values you need as arguments.
 > - This API uses Next.js' built-in cache to persist the result across requests and deployments. See [Caching and Revalidating](/docs/app/getting-started/caching).
 
+## Unsupported operations
+
+The function passed to `unstable_cache` cannot depend on the incoming request. Read values from `cookies()` or `headers()` before calling the cached function, then pass those values as arguments so they become part of the cache key.
+
+The cached function also cannot:
+
+- Call `connection()`, which requires an incoming request
+- Enable or disable draft mode
+- Call `revalidateTag()`, `updateTag()`, or `revalidatePath()` during cache execution
+- Call a function that uses the `use cache: private` directive
+
+Perform request-dependent work before calling the cached function. Perform mutations and revalidation afterward from a Server Action or Route Handler.
+
 ## Parameters
 
 ```jsx

errors/cache-life-outside-use-cache.mdx

@@ -0,0 +1,44 @@
+---
+title: Cannot call `cacheLife()` outside `use cache`
+---
+
+## Why This Error Occurred
+
+The `cacheLife()` function configures the `stale`, `revalidate`, and `expire` times for a cache entry. Call it from a function or component that uses the `use cache` or `use cache: private` directive. When you call `cacheLife()` outside a cached function, there is no cache entry to configure.
+
+```jsx filename="app/page.js" highlight={4}
+import { cacheLife } from 'next/cache'
+
+export default async function Page() {
+  cacheLife('hours') // No cache entry to configure
+  return <p>...</p>
+}
+```
+
+## Possible Ways to Fix It
+
+Move `cacheLife()` inside the cached function whose lifetime you want to set.
+
+```jsx filename="app/page.js" highlight={5}
+import { cacheLife } from 'next/cache'
+
+async function getProducts() {
+  'use cache'
+  cacheLife('hours') // Configures this cache entry
+  return db.products.findMany()
+}
+
+export default async function Page() {
+  const products = await getProducts()
+  return <p>...</p>
+}
+```
+
+If you don't intend to cache the function or component, remove the `cacheLife()` call.
+
+## Useful Links
+
+- [`cacheLife()` function](/docs/app/api-reference/functions/cacheLife)
+- [`cacheTag()` function](/docs/app/api-reference/functions/cacheTag)
+- [`use cache` directive](/docs/app/api-reference/directives/use-cache)
+- [`use cache: private` directive](/docs/app/api-reference/directives/use-cache-private)

errors/cache-tag-outside-use-cache.mdx

@@ -0,0 +1,45 @@
+---
+title: Cannot call `cacheTag()` outside `use cache`
+---
+
+## Why This Error Occurred
+
+The `cacheTag()` function attaches one or more tags to a cache entry so you can later revalidate it with `revalidateTag()`. Call it from a function or component that uses the `use cache` or `use cache: private` directive. When you call `cacheTag()` outside a cached function, there is no cache entry to tag.
+
+```jsx filename="app/page.js" highlight={4}
+import { cacheTag } from 'next/cache'
+
+export default async function Page() {
+  cacheTag('products') // No cache entry to tag
+  return <p>...</p>
+}
+```
+
+## Possible Ways to Fix It
+
+Move `cacheTag()` inside the cached function whose entry you want to tag.
+
+```jsx filename="app/page.js" highlight={5}
+import { cacheTag } from 'next/cache'
+
+async function getProducts() {
+  'use cache'
+  cacheTag('products') // Tags this cache entry
+  return db.products.findMany()
+}
+
+export default async function Page() {
+  const products = await getProducts()
+  return <p>...</p>
+}
+```
+
+If you don't intend to cache the function or component, remove the `cacheTag()` call. To revalidate the tag later, call [`revalidateTag()`](/docs/app/api-reference/functions/revalidateTag) from a Server Action or Route Handler.
+
+## Useful Links
+
+- [`cacheTag()` function](/docs/app/api-reference/functions/cacheTag)
+- [`cacheLife()` function](/docs/app/api-reference/functions/cacheLife)
+- [`use cache` directive](/docs/app/api-reference/directives/use-cache)
+- [`use cache: private` directive](/docs/app/api-reference/directives/use-cache-private)
+- [`revalidateTag()` function](/docs/app/api-reference/functions/revalidateTag)

errors/next-request-in-use-cache.mdx

@@ -1,51 +1,57 @@
 ---
-title: Cannot access `cookies()` or `headers()` in `"use cache"`
+title: Cannot access request data in `use cache`
 ---
 
 ## Why This Error Occurred
 
-A function is trying to read from the current incoming request inside the scope of a function annotated with `"use cache"`. This is not supported because it would make the cache invalidated by every request which is probably not what you intended.
+A cached function tried to access the incoming request. APIs such as `cookies()`, `headers()`, `searchParams`, and `connection()` depend on the request and cannot be called inside a function that uses the `use cache` directive. This error can also occur when you pass unresolved request data into a cached function during prerendering. You can read draft mode inside a cached function, but enable or disable it outside.
+
+A cached function can also stall if it awaits a promise stored outside the function, such as one kept in a module-scoped `Map` for deduplication.
 
 ## Possible Ways to Fix It
 
-Instead of calling this inside the `"use cache"` function, move it outside the function and pass the value in as an argument. The specific value will now be part of the cache key through its arguments.
+Read and resolve request data outside the cached function, then pass only the values you need as arguments. Call `connection()` and enable or disable draft mode outside the cached function as well.
+
+If a module-scoped cache or deduplication layer stores promises, remove it. The `use cache` directive already deduplicates calls with the same arguments within a render pass and across requests for as long as the cache entry lasts.
 
 Before:
 
 ```jsx filename="app/page.js" highlight={5}
 import { cookies } from 'next/headers'
 
-async function getExampleData() {
-  "use cache"
+async function getGreeting() {
+  'use cache'
   const isLoggedIn = (await cookies()).has('token')
-  ...
+  return isLoggedIn ? 'Welcome back' : 'Welcome'
 }
 
 export default async function Page() {
-  const data = await getExampleData()
-  return ...
+  const greeting = await getGreeting()
+  return <p>{greeting}</p>
 }
 ```
 
 After:
 
-```jsx filename="app/page.js" highlight={9}
+```jsx filename="app/page.js" highlight={9,10}
 import { cookies } from 'next/headers'
 
-async function getExampleData(isLoggedIn) {
-  "use cache"
-  ...
+async function getGreeting(isLoggedIn) {
+  'use cache'
+  return isLoggedIn ? 'Welcome back' : 'Welcome'
 }
 
 export default async function Page() {
   const isLoggedIn = (await cookies()).has('token')
-  const data = await getExampleData(isLoggedIn)
-  return ...
+  const greeting = await getGreeting(isLoggedIn)
+  return <p>{greeting}</p>
 }
 ```
 
 ## Useful Links
 
 - [`headers()` function](/docs/app/api-reference/functions/headers)
 - [`cookies()` function](/docs/app/api-reference/functions/cookies)
+- [`connection()` function](/docs/app/api-reference/functions/connection)
 - [`draftMode()` function](/docs/app/api-reference/functions/draft-mode)
+- [`use cache` directive](/docs/app/api-reference/directives/use-cache)

errors/revalidate-in-use-cache.mdx

@@ -0,0 +1,41 @@
+---
+title: Cannot revalidate during render, inside a cached function, or in `generateStaticParams`
+---
+
+## Why This Error Occurred
+
+The `revalidateTag()` and `revalidatePath()` functions invalidate cached data. To keep cache state consistent, call them from a Server Action or Route Handler. Next.js throws this error when you call either function during rendering, from a cached function, or from `generateStaticParams`.
+
+```jsx filename="app/products/page.js" highlight={5}
+import { revalidateTag } from 'next/cache'
+
+export default async function Page() {
+  const products = await db.products.findMany()
+  revalidateTag('products', 'max') // Cannot revalidate during render
+
+  return <p>{products.length} products</p>
+}
+```
+
+## Possible Ways to Fix It
+
+Call `revalidateTag()` or `revalidatePath()` from the Server Action or Route Handler itself. Do not call either function during rendering or from a function that uses the `use cache` directive or `unstable_cache()`.
+
+```jsx filename="app/actions.js" highlight={6}
+'use server'
+import { revalidateTag } from 'next/cache'
+
+export async function saveProduct(data) {
+  await db.products.create(data)
+  revalidateTag('products', 'max') // Runs outside any cached function
+}
+```
+
+To tag the cache entry that this revalidates, call [`cacheTag()`](/docs/app/api-reference/functions/cacheTag) inside the function that uses the `use cache` directive to read the data.
+
+## Useful Links
+
+- [`revalidateTag()` function](/docs/app/api-reference/functions/revalidateTag)
+- [`revalidatePath()` function](/docs/app/api-reference/functions/revalidatePath)
+- [Revalidating data](/docs/app/getting-started/revalidating)
+- [`use cache` directive](/docs/app/api-reference/directives/use-cache)

errors/use-cache-private-composition.mdx

@@ -0,0 +1,46 @@
+---
+title: 'Invalid `use cache: private` composition'
+---
+
+## Why This Error Occurred
+
+The `use cache: private` directive lets a cached function access request-specific data. Next.js stores its results only in the browser's memory. Private cached functions cannot run inside shared caches or without an active request. This error occurs when a private cached function is:
+
+- **Nested inside a public `use cache` directive.** A shared cached function can reuse its result across users, so it cannot contain a private cached function. Nest a private cached function only inside another private cached function.
+- **Used inside `unstable_cache()`.** `unstable_cache()` is a shared cache and has the same restriction.
+- **Used without an active request.** A private cached function depends on the current request, so it cannot run during build-time contexts such as `generateStaticParams`.
+
+```jsx filename="app/page.js" highlight={2,7}
+async function PrivateSegment() {
+  'use cache: private'
+  return <p>Private</p>
+}
+
+export default async function Page() {
+  'use cache' // A public cache cannot contain a private one
+  return <PrivateSegment />
+}
+```
+
+## Possible Ways to Fix It
+
+Nest a private cached function only inside another private cached function. You can also call it directly from a component or function that runs during a request. Do not place it inside a public cached function, `unstable_cache()`, or a build-time context.
+
+```jsx filename="app/page.js" highlight={7}
+async function PrivateSegment() {
+  'use cache: private'
+  return <p>Private</p>
+}
+
+export default async function Page() {
+  // No surrounding "use cache". The private segment runs per request.
+  return <PrivateSegment />
+}
+```
+
+If the data is the same for every user, use the `use cache` directive so Next.js can prerender and reuse the result. If you need per-user data, read it during the request instead of in `generateStaticParams`.
+
+## Useful Links
+
+- [`use cache: private` directive](/docs/app/api-reference/directives/use-cache-private)
+- [`use cache` directive](/docs/app/api-reference/directives/use-cache)

evals/evals/agent-043-view-transitions/EVAL.ts

@@ -5,8 +5,11 @@
  * product gallery app covering shared element morphs, directional navigation,
  * Suspense reveal animations, and accessibility.
  *
+ * View transitions need no next.config flag: experimental.viewTransition was
+ * inert and removed in #96098, and the docs now say "works with no
+ * configuration" — so nothing here may grade the config either way.
+ *
  * Tricky because agents may:
- * - Not know about the experimental.viewTransition flag in next.config
  * - Try to call document.startViewTransition manually instead of using
  *   React's <ViewTransition> component
  * - Import ViewTransition from a third-party library instead of 'react'
@@ -73,17 +76,6 @@ function readAllCssFiles(): string {
   return unique.map((f) => readFileSync(f, 'utf-8')).join('\n')
 }
 
-test('next.config enables viewTransition', () => {
-  const configPath = existsSync(join(process.cwd(), 'next.config.ts'))
-    ? 'next.config.ts'
-    : 'next.config.js'
-  const content = stripComments(
-    readFileSync(join(process.cwd(), configPath), 'utf-8')
-  )
-
-  expect(content).toMatch(/viewTransition\s*:\s*true/)
-})
-
 test('ViewTransition is imported from react', () => {
   const allSource = readAllSourceFiles()
 

lerna.json

@@ -15,5 +15,5 @@
       "registry": "https://registry.npmjs.org/"
     }
   },
-  "version": "16.4.0-canary.12"
+  "version": "16.4.0-canary.13"
 }

packages/create-next-app/package.json

@@ -1,6 +1,6 @@
 {
   "name": "create-next-app",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "keywords": [
     "react",
     "next",

packages/devlow-bench/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@vercel/devlow-bench",
   "private": true,
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "description": "Benchmarking tool for the developer workflow",
   "repository": {
     "type": "git",

packages/eslint-config-next/package.json

@@ -1,6 +1,6 @@
 {
   "name": "eslint-config-next",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "description": "ESLint configuration used by Next.js.",
   "license": "MIT",
   "repository": {
@@ -12,7 +12,7 @@
     "dist"
   ],
   "dependencies": {
-    "@next/eslint-plugin-next": "16.4.0-canary.12",
+    "@next/eslint-plugin-next": "16.4.0-canary.13",
     "eslint-import-resolver-node": "^0.3.6",
     "eslint-import-resolver-typescript": "^3.5.2",
     "eslint-plugin-import": "^2.32.0",

packages/eslint-plugin-internal/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@next/eslint-plugin-internal",
   "private": true,
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "description": "ESLint plugin for working on Next.js.",
   "exports": {
     ".": "./src/eslint-plugin-internal.js"

packages/eslint-plugin-next/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@next/eslint-plugin-next",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "description": "ESLint plugin for Next.js.",
   "main": "dist/index.js",
   "types": "dist/index.d.ts",

packages/font/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@next/font",
   "private": true,
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "repository": {
     "url": "vercel/next.js",
     "directory": "packages/font"

packages/next-bundle-analyzer/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@next/bundle-analyzer",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "main": "index.js",
   "types": "index.d.ts",
   "license": "MIT",

packages/next-codemod/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@next/codemod",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "license": "MIT",
   "repository": {
     "type": "git",

packages/next-env/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@next/env",
-  "version": "16.4.0-canary.12",
+  "version": "16.4.0-canary.13",
   "keywords": [
     "react",
     "next",