Next.js Release Notes

Note

This release is backporting bug fixes. It does not include all pending features/changes on canary.

Core Changes

• fix: ensure onRequestError is invoked when otel enabled (#83343)
• fix: devtools initial position should be from next config (#83571)
• [devtool] fix overlay styles are missing (#83721)
• Turbopack: don't match dynamic pattern for node_modules packages (#83176)
• Turbopack: don't treat metadata routes as RSC (#82911)
• [turbopack] Improve handling of symlink resolution errors in track_glob and read_glob (#83357)
• Turbopack: throw large static metadata error earlier (#82939)
• fix: error overlay not closing when backdrop clicked (#83981)
• Turbopack: flush Node.js worker IPC on error (#84077)

Misc Changes

• [CNA] use linter preference (#83194)
• CI: use KV for test timing data (#83745)
• docs: september improvements and fixes (#83997)

Credits

Huge thanks to @yiminghe, @huozhi, @devjiwonchoi, @mischnic, @lukesandberg, @ztanner, @icyJoseph, @leerob, @fufuShih, @dwrth, @aymericzip, @obendev, @molebox, @OoMNoO, @pontasan, @styfle, @HondaYt, @ryuapp, @lpalmes, and @ijjk for helping!

Note

This release is backporting bug fixes. It does not include all pending features/changes on canary.

Core Changes

• fix: aliased navigations should apply scroll handling (#82900)
• Turbopack: fix invalid NFT entry with file behind symlink (#82887)
• fix: typesafe linking to route handlers and pages API routes (#82858)
• fix: change "noUnknownAtRules" to "warn" for Biome (#82974)
• fix: add path normalization to getRelativePath for Windows (#82918)
• feat: add typesafety with config.typedRoutes to redirect() and permanentRedirect() (#82860)
• fix: avoid importing types that will be unused (#82856)
• fix: update the config.api.responseLimit type (#82852)
• fix: update validation return types (#82854)

Credits

Huge thanks to @bgub, @mischnic, and @ztanner for helping!

Core Changes

• Use and enforce exhaustive switch statements for work unit store: #81577
• Enable @typescript-eslint/switch-exhaustiveness-check rule: #81583
• [dynamicIO] use RSC dynamicness to control partial vs complete PPR result: #81627
• [dynamicIO] Do not use React.unstable_postpone() : #81652
• feat: new detachable panel UI: #81483
• Turbopack: content-hash PageLoaderAsset: #81450
• [segment explorer] fix content overflow styling: #81649
• Improve reliability of owner stacks for async I/O errors: #81501
• fix(router): Prevent redirect loop on root data requests with basePath: #81096
• Ensure custom NextServer config is honored: #81681
• Fix before interactive incorrectly render css: #81146
• perf: memorize exclude function in webpack config: #81525
• Also enforce experimental features when there's no next config file: #81679
• feat(next/image): warn when images.qualities is undefined: #81690
• feat(build): optimize filterUniqueParamsCombinations to generate sub-combinations: #81321
• Update NextAdapter type and re-export: #81692
• upgrade to [email protected]: #80123
• [metadata] replace for initial body icon case: #81688
• [segment explorer] remove dev panel ui flag: #81670
• Simplify running test apps locally with ppr or dynamicIO enabled: #81668
• [turbopack] Return cached Promise from turbopack_load_by_url : #81663
• Upgrade React from 97cdd5d3-20250710 to 2f0e7e57-20250715 : #81678
• Delete unused renderToString function: #81707
• Discard prerendered route handler data from FS cache after revalidation: #81611
• Upgrade React from 2f0e7e57-20250715 to d85ec5f5-20250716 : #81708
• Ignore pending revalidations during prerendering: #81621
• [turbopack] Clear chunk cache on HMR instead of creating new next-server VM: #81664
• fix: rootParams should throw in client when fallbackParams are not present: #81711
• perf(build): optimize buildAppStaticPaths performance and add helper function: #81386
• Turbopack: Support string without options for @next/mdx: #81713
• [Segment Cache] Support dynamic head prefetching: #81677
• [sourcemaps] Consistent cursor columns: #81375
• fix: revert client segment route changes for sub shell generation: #81731
• fix: pages router metadata bugs with React 19: #81733
• Improve error handling for headers / cookies / draftMode in 'use cache' : #81716
• [devtool] fix duplicate rendered indicator on server: #81729
• [devtool] enable segment explorer by default: #81737
• [turbopack] Stop exposing globals from Turbopack runtime: #81727
• Remove unnecessary await: #81761
• [chore] bump zod to latest v3: #81757
• feat(turbopack): Log anonymized internal error (panic) information to telemetry: #81272
• fix: revert client segment route changes for sub shell generation: #81740
• bugfix: static resources staleTime should be renewed once refetched: #81771
• [devtool] move font styling to global.css: #81782
• [devtool] copy decoded info of error details: #81735
• fix(build): add sourcePage context for PPR dynamic route lambda creation: #81781
• refactor: rename experimental.dynamicIO to experimental.cacheComponents: #81562
• Properly handle hanging promise rejections during prerendering: #81754
• Upgrade React from d85ec5f5-20250716 to dffacc7b-20250717 : #81767
• Refactor: Get rid of overly generic getExpectedRequestStore function: #81791
• [devtool] migrate css reset to global.css: #81783
• [dev-tools] Robust shortcut detection: #81756
• [segment explorer] hide for pages router: #81813
• [devtool] fix scrollbar styling: #81814
• fix(ppr): ensure fallback route params trigger dynamic resume: #81812
• [devtools] restart server pending state: #80858
• Turbopack: fix dist dir on Windows: #81758
• fix: remove boundary sentinel from RSC responses: #81857
• [sourcemaps] Try VM for retrieving source maps first: #81869
• [devtools] save user config inside .next/cache : #81807
• Server: Remove unused code: #81886
• refactor: encapsulate content type within RenderResult: #81861
• refactor: handle null RenderResult responses gracefully: #81895
• Upgrade React from dffacc7b-20250717 to e9638c33-20250721 : #81899
• chore(devtools): sync todos to linear: #81901
• Introduce 'use cache: private' : #81816
• chore(deps): update browserslist : #81851
• Remove web-server from edge-ssr-app: #81389
• Stabilize node middleware support: #81907
• Add run-turbopack-compiler trace span: #81917
• fix: support calling onClose multiple times in edge-ssr-app: #81911
• fix: logging the correct process for listened port: #81903
• Build: Include rewrites in manifest generation: #81894
• Routing: Clean up some code: #81932
• [sourcemaps] Ensure codeframe when calling Client Functions from Server: #81918
• [segment explorer] missing file suggestion: #81617
• [turbopack] Always print trace labels in headers: #81728
• Revert "[metadata] use https protocol for schema urls": #81934
• Upgrade React from e9638c33-20250721 to 7513996f-20250722 : #81940
• Upgrade to swc v33: #81750
• Remove extra base-server code: #81944
• Turbopack: flatten sourceInfo to avoid objects, reorder args, compress node.js entry: #81545
• Fix dynamicParams false layout case in dev: #81990
• Initial MCP implementation: #81770
• Fix: Unresolved param in x-nextjs-rewritten-query: #81991
• Turbopack: Add an option to use system TLS certificates (fixes #79060, fixes #79059 ): #81818
• Turbopack: Remove unused proxy option in turbo-tasks-fetch, lightly document HTTP_PROXY/HTTPS_PROXY environment variables: #81905
• Upgrade React from 7513996f-20250722 to edac0dde-20250723 : #81984
• [devtools] Cleanup folder structure: #82012
• [devtools] Fix "open in editor" for locations in stackframes: #82013
• [Segment Cache] Fix: Key by rewritten search: #81986
• Upgrade vercel og and remove yoga type patching: #81937
• [perf] cache load config results: #80570
• Turbopack: use prototype for turbopack context for better runtime performance: #81547
• [reactcompiler] Test with latest RC: #82002
• [devtools] Fix various exhaustive-deps violations: #82010
• [devtools] Apply React Compiler to Next.js DevTools source: #82004
• Upgrade React from edac0dde-20250723 to 3d14fcf0-20250724 : #82020
• Adjusted the warning message to be more descriptive: #82054
• Track fallback params on workUnitStore: #82003
• Fix API stripping JSON incorrectly: #82061
• Upgrade React from 3d14fcf0-20250724 to 19baee81-20250725 : #82063
• use FetchStrategy to control prefetching behavior everywhere: #82032
• [Segment Cache] set fetchStrategy on segments from a dynamic request: #82059
• Revert "Upgrade vercel og and remove yoga type patching (#81937)": #82066
• Optimize segment data routes: #82033
• Turbopack: write tasks doesn't need to be session dependent, as effects will restore: #78727
• [sourcemaps] Fully sourcemap stacks on the Server: #81904
• fix(Rspack): use loaderContext.utils.contextify to replace ModuleFilenameHelpers.createFilename: #82104
• next/root-params: #80255
• fix(next/image): fix image-optimizer.ts headers: #82114
• Upgrade React from 19baee81-20250725 to eaee5308-20250728 : #82120
• Fix validateRSCRequestHeaders incorrect redirect: #82119
• fix(next/image): improve and simplify detect-content-type: #82118
• [CacheComponents] Use fallback params when validating dynamic routes in dev: #82069
• Extract getDynamicParam to a shared module: #82137
• Fix i18n fallback: false collision: #82136
• [segment explorer] normalize path when running inside monorepo: #82146
• [segment explorer] windows compatibility: #82147
• Upgrade React from eaee5308-20250728 to 9be531cd-20250729 : #82159
• Ensure setAssetPrefix updates config instance: #82160
• Revert "Fix tracing of server actions imported by client components (#78968)": #82161
• Remove useMDXComponents argument: #80871
• Fix RSC hash validation for middleware external rewrites: #82176
• @next/codemod: update docs url in README: #82135
• @next/codemod: Add experimental.turbo to turbopack codemod for Next.js configs: #82134
• refactor: lowercase app router header values: #82169
• Strip internals from NextRequest types: #82172
• allow root params access in private caches: #82125
• [devtool] bump base-ui to 1.0.0-beta.2: #82206
• Upgrade @vercel og: #82201
• Upgrade React from 9be531cd-20250729 to 9784cb37-20250730 : #82207
• Fix: the unexpected clearing of symbolic link directories: #82191
• [next-dev] Set TURBOPACK env before loading config: #82162
• fix: display multiple lockfile warn if neither outputFileTracingRoot or turbopack.root option is provided: #82164
• Revert "Initial MCP implementation (#81770)": #82217
• Revert "Upgrade @vercel og (#82201)": #82219
• Fix: Don't bail out of prefetch if head is missing: #82216
• Upgrade React from 9784cb37-20250730 to c260b38d-20250731 : #82247
• [Cache Components] Runtime prefetching: #81088
• Parse dynamic params on the client: #82185
• Mark bun builtin modules as external (fixes #75220): #77616
• Turbopack: Compact only at the end for short sessions: #82224
• feat: add fallback root params support for prefetch segment data routes: #82282
• feat: add route context to prerender error messages: #82283
• feat: automatically generate route types: #81396
• [Cache Components] Reset PrerenderStore after generating RSC payload: #82286
• Include eslint-plugin-react-hooks in React sync: #82294
• [devtools] Remove unnecessary cascading update: #82295
• Turbopack: name the module factory function: #73553
• Update font data: #82292
• fix: next/root-params erroring when rerendering after action: #82326
• Remove params from segment path: #82249
• Upgrade React from c260b38d-20250731 to be11cb5c-20250804 : #82339
• fix: OTel root span should indicate error status on exceptions: #82212
• [Cache Components] Allow span creation while prerendering: #82350
• feat(tu... (truncated for brevity)