Misc Changes

• docs: create-next-app react-compiler and new prompts: #85213
• docs: cache components - introduction: #85196
• docs: use cache feedback: #85169
• docs: stabilize apis in docs: #85219
• docs: revalidateTag immediate expiration in Route Handlers: #85223
• Docs/use cache feedback 2: #85222
• docs: added use cache: remote docs: #85145
• docs: proxy runtime defaults to nodejs: #85204
• chore: cache components feedback: #85241

Credits

Huge thanks to @icyJoseph, @wyattjoh, and @devjiwonchoi for helping!

Core Changes

• Development: Don't import app-router / hot-reloader through next/link in application code: #83656
• Remove clientParamParsing requirement from RDC for Navigations: #83661
• Upgrade React from 6b70072c-20250909 to 886b3d36-20250910: #83650
• Turbopack: Use readFileSync / writeFileSync for manifest writing: #83694
• Upgrade React from 886b3d36-20250910 to f3a80361-20250911: #83696
• Don't create client-side debug channel if the feature is disabled: #83699
• fix: dev should produce the correct default fallback regex to match builds/Turbopack: #83701
• [devtool] fix overlay styles are missing: #83721
• Revert "Remove clientParamParsing requirement from RDC for Navigations": #83725
• Only enable unhandledRejection filtering when opted in: #83726
• Fix index data route for adapter build-complete: #83730
• Remove leading underscore for unhandledRejection envvar: #83732
• Upgrade React from f3a80361-20250911 to 93d7aa69-20250912: #83729
• Upgrade React from 93d7aa69-20250912 to 8a8e9a7e-20250912: #83742
• Fix reentrancy of unhandledRejection filtering: #83741
• Fix type for unhandled rejection handler process.removeListener: #83748
• [OTel] fix: Root span name should not include high cardinality URL: #75416
• Turbopack: Remove matchers.reload() call on each request: #83720
• [Breaking] Flat config as default in @next/eslint-plugin-next: #83763
• fix: Rspack splitChunks.chunks regex: #83670
• Revert "Turbopack: Remove matchers.reload() call on each request": #83819
• fix: unstable_cache should perform blocking revalidation during ISR revalidation: #83820
• fix(Rspack): resolve HMR unresponsiveness or unexpected full reload & update dev snapshot: #83480
• Allow next.config.mts for Node.js native TS resolver: #83556
• chore: Ensure Import Trace starts in a newline: #83638
• Development: Remove matchers.reload() on each request: #83829
• Upgrade React from 8a8e9a7e-20250912 to 5e0c951b-20250916: #83850
• Bump typescript 5.9.2: #83833
• Allow headers, rewrites and redirects to be defined as sync functions: #83743
• Turbopack: Optimize addedRoutes and removedRoutes calculation: #83840
• [next-config-ts] Set Node.js native TS loader fallback flag to process.env: #83832
• Development: Clarify TypescriptStatus in watcher: #83857
• Upgrade sharp dependency to version ^0.34.4: #83892
• Upgrade React from 5e0c951b-20250916 to 128abcfa-20250917: #83906
• Add native ts resolver docs link to transpile-config: #83914
• OTel: use srcPage for templates when next.route is unavailable: #83911
• Remove inline CSS sourcemaps from next-devtools: #83917
• Development: Move all TypeScript related work in watcher together: #83912
• [Cache Components] Allow sync IO inside console methods : #83843
• Upgrade React from 128abcfa-20250917 to 84af9085-20250917: #83959
• Build: Add .next/trace-build with high level trace: #83949
• Remove force writing **/*.mts to tsconfig: #83967
• feat: Isolate dev build from prod: #83961
• Remove JS size reporting from next build: #83815
• Docs/workspace setup: #83490
• Turbopack: support import ... with {type: "bytes"}: #83896
• fix: error overlay not closing when backdrop clicked: #83981
• Upgrade React from 84af9085-20250917 to d415fd3e-20250919: #84003
• fix: worker logs should still support color: #84024
• Update font data: #84005
• Allow passing port to next internal trace: #83907
• Turbopack: error when importing Typescript in node_modules: #83990
• Turbopack: Deterministic builds (prerender-manifest, .next/package.json, ./next/postcss.js): #84081
• Turbopack: Fix babel-loader (allowing built-in or manual configuration): #82676
• [Cache Components] allow using headers() in runtime prefetches: #83838
• [Breaking] Remove deprecated publicRuntimeConfig and serverRuntimeConfig: #83944
• Turbopack: mode to disable tracing: #83683
• babel-loader: Fix a few issues with config caching: #83973
• Turbopack: Merge babel-loader and react-compiler configuration logic to avoid running babel twice: #83502
• [breaking]: enable router scroll optimization by default: #84102
• Fix layout for ssgPageRoutes in the file tree: #84104
• Turbopack: Remove useless 'default' built-in webpack loader condition: #84111
• Fix: Client should auto reload after server restarts: #83971
• trace-build: Add missing spans: #84080
• Development: Remove TypeScript from the hot path during bootup: #84090
• Guide users to experimental.cacheComponents config: #84121
• Development: Only load webpack when used: #84123
• Turbopack: Skip loading webpack plugin: #84125
• Development: Only load createEnvDefinitions when used: #83935
• BREAKING CHANGE!: bump default images.minimumCacheTTL from 1 min to 4 hours: #84105
• Feat: Add Model Context Protocol (MCP) server to Next.js dev server: #84100
• Upgrade React from d415fd3e-20250919 to 1eca9a27-20250922: #84093
• Turbopack: Remove the deprecated .turbo config object: #84109
• Flag excess properties in Next.js config with TypeScript: #84069
• docs: update Security section to direct disclosures : #84156
• ci: Enable experimental.isolatedDevBuild for test-experimental-dev: #84099
• [turbopack] Ensure React Compiler options are based dev vs prod: #84062
• Enable anonymous function naming in React Compiler: #84070
• Revert "[Breaking] Remove deprecated publicRuntimeConfig and serverRuntimeConfig (#83944)": #84167
• Fix double comma in build manifest: #84131
• [turbopack] set app dir only to true when no pages entries detected: #84144
• Split code-frame into separate compiled package: #84174
• refactor: separate forward browser logs utils: #84151
• Upgrade React from 1eca9a27-20250922 to e2332183-20250924: #84189
• [Cache Components] default to filtering unhandledRejection after abort: #84192
• fix: prevent URL mutation in router rewrites: #83963
• fix(server): fix pages router resume router matching: #84158
• Feat: get_errors MCP endpoint: #84161
• Add internal environment variable for enabling React Compiler: #84176
• [devtools] Disable React's default Transition indicator: #84202
• Upgrade React from e2332183-20250924 to b0c1dc01-20250925: #84248
• Feat: get_page_metadata MCP endpoint: #84211
• feat: capture logs into logging file during development: #84183
• babel-loader: Avoid calling expensive isReactCompilerRequired check when we must run Babel anyways: #84103
• [mcp] expose logging: #84226
• Move config.turbopack.moduleIds to config.experimental.turbopackModuleIds: #84230
• Show invalid default export errors during prerendering: #84242
• fix: make sure caller exists in babel preset: #84154
• [mcp] allow to enable mcp server through env var: #84278
• fix(metadata): make formatDetection respect true/false properly: #83924
• Upgrade React from b0c1dc01-20250925 to df38ac9a-20250926: #84276
• Add a --webpack flag and default --turbopack to true: #84216
• fix: Update URL resolution logic to handle search parameters on root path /?foo=bar: #78262
• [Breaking] Remove deprecated sync access to Dynamic APIs: #84179
• Move config.turbopack.moduleIds to config.experimental.turbopackModuleIds: #84230
• Show invalid default export errors during prerendering: #84242
• fix: make sure caller exists in babel preset: #84154
• [mcp] allow to enable mcp server through env var: #84278
• fix(metadata): make formatDetection respect true/false properly: #83924
• Upgrade React from b0c1dc01-20250925 to df38ac9a-20250926: #84276
• Add a --webpack flag and default --turbopack to true: #84216
• fix: Update URL resolution logic to handle search parameters on root path /?foo=bar: #78262
• [Breaking] Remove deprecated sync access to Dynamic APIs: #84179
• Turbopack: only write merged manifests when they have been changed: #84261
• Turbopack: add separate turbopackPersistentCachingForBuild/ForDev flags: #84215
• Revert "Add a --webpack flag and default --turbopack to true (#84216)": #84348
• Upgrade React from df38ac9a-20250926 to d15d7fd7-20250929: #84347
• Mark React Compiler integration as stable: #84220
• [cna] Add reactCompiler option: #82251
• Turbopack: remove canary version check for turbopackPersistentCachingForDev: #84277
• [turbopack] Add support for debug_ids: #84319
• Revert "Revert "Add a --webpack flag and default --turbopack to true (#84216)"": #84351
• [Breaking] Remove AMP codemod: #84356
• [Breaking] Remove deprecated built-in AMP: #84312
• auto-enable clientParamParsing and clientSegmentCache w/ cacheComponents: #84250
• [mcp] get server action tool: #84382
• Revert "Revert "Revert "Add a --webpack flag and default --turbopack to true (#84216)""": #84389
• Update otel test assertions and pages span_name: #84393
• [Breaking] Bump minimum TypeScript version to 5.1.0: #84384
• Upgrade React from d15d7fd7-20250929 to ef889445-20250930: #84383
• [Breaking] Remove deprecated unstable_rootParams: #84373
• [metadata] remove falsy dynamicParams approach: #84405
• fix: next rspack binding NextExternalsPlugin: #84303
• Development: Skip route matching when there is an existing match: #84227
• Revert "auto-enable clientParamParsing and clientSegmentCache w/ cacheComponents": #84419
• Upgrade React from ef889445-20250930 to 548235db-20251001: #84416
• [Breaking] Update default browserslist config: #84401
• Upgrade React from 548235db-20251001 to 1bd1f01f-20251001: #84417
• Allow metadataBase to be a string URL in addition to URL instance: #84297
• Upgrade React from 1bd1f01f-20251001 to 86181134-20251001: #84427
• [mcp] logging file should be reset for each session: #84425
• Revert "Revert "Revert "Revert "Add a --webpack flag and default --turbopack to true (#84216)"""": #84394
• Optimize isMetadataRoute function: #84409...

Core Changes

• Fix: CSS asset URLs broken with experimental.inlineCss: #85140
• Update routes generation for build-complete: #85017
• [cache components] move experimental.cacheHandlers out of experimental: #85157
• Don't assign displayName to the internal Promises: #85178
• Assign name to hydration stream: #85179
• fix: add backwards compat for middleware → proxy field renames: #85183
• [turbopack] Implement improved deobfuscation for free calls and module identifiers.: #85060
• Improve Proxy invalid export error message: #84887
• Fix Activity boundary names: #85185
• [codemod] Install ESLint v9 if version under for next-lint-to-eslint-cli: #85182
• [upgrade] Version gate adding --turbopack flag: #85180
• Tweaks to blocking route error message: #85191
• Remove layout-router sticky/fixed debug warning: #85193
• [cache components] persist cache bypass UI until it's disabled: #85190
• Only allow node runtime in proxy: #85139
• logger: skip logging full element: #85194

Misc Changes

• Docs: Explain Sass tilde import difference: #85041
• Turbopack: don't fail on export type in use server: #85054
• Turbopack: speedup module merging: #85043
• docs: remove experimental_ppr route segment config: #85188
• Rename "blocking route" error docs page: #85189
• docs: upgrade from 15 to 16: #85176

Credits

Huge thanks to @timneutkens, @gaojude, @ijjk, @ztanner, @sebmarkbage, @mischnic, @icyJoseph, @acdlite, @serhalp, @lukesandberg, @devjiwonchoi, and @huozhi for helping!

Core Changes

• Fix: CSS asset URLs broken with experimental.inlineCss: #85140
• Update routes generation for build-complete: #85017
• [cache components] move experimental.cacheHandlers out of experimental: #85157
• Don't assign displayName to the internal Promises: #85178
• Assign name to hydration stream: #85179
• fix: add backwards compat for middleware → proxy field renames: #85183
• [turbopack] Implement improved deobfuscation for free calls and module identifiers.: #85060
• Improve Proxy invalid export error message: #84887
• Fix Activity boundary names: #85185
• [codemod] Install ESLint v9 if version under for next-lint-to-eslint-cli: #85182
• [upgrade] Version gate adding --turbopack flag: #85180
• Tweaks to blocking route error message: #85191
• Remove layout-router sticky/fixed debug warning: #85193
• [cache components] persist cache bypass UI until it's disabled: #85190
• Only allow node runtime in proxy: #85139
• logger: skip logging full element: #85194

Misc Changes

• Docs: Explain Sass tilde import difference: #85041
• Turbopack: don't fail on export type in use server: #85054
• Turbopack: speedup module merging: #85043
• docs: remove experimental_ppr route segment config: #85188
• Rename "blocking route" error docs page: #85189
• docs: upgrade from 15 to 16: #85176

Credits

Huge thanks to @timneutkens, @gaojude, @ijjk, @ztanner, @sebmarkbage, @mischnic, @icyJoseph, @acdlite, @serhalp, @lukesandberg, @devjiwonchoi, and @huozhi for helping!

Core Changes

• Fix subtree layout alignment for route summary in next build: #85137
• [codemod] Remove runtime config when running middleware-to-proxy: #85075
• [turbopack] Improve the multiple bundler flags messge to note that perhaps your package.json is the problem: #85118
• Add Learn more docs to Middleware deprecation warning: #84711
• [BF Cache]: skip lazyData fetch logic for inactive segments: #85142
• Pass startTime to initial RSC payload stream: #85144
• guard navigation use hooks for React 18: #85151
• [turbopack] Don't warn on the lightning css experimental option: #84913
• Turbopack: Remove redundant log line, increase delay for compiling log message: #85133
• Make params and searchParams new Promises: #85158
• Name "cache" streams for React DevTools: #85159
• Use cacheMaxMemorySize config in default cache handler: #85153
• Omit params to from client segments: #84883
• enable experimental.routerBfCache behind cacheComponents: #84923
• [Cache Components] Allow stale longer than expire in cacheLife: #85115
• Update Activity names given to routes: #85155
• use port zero for --inspect when forking, if used by parent: #85128
• Update blocking prerender error message: #85087

Misc Changes

• Turbopack: Disable LightningCSS MediaRangeSyntax feature: #85086
• Don't expliclitly set the --turbopack flag in Create Next App, it is no longer necessary: #85117
• [turbopack] Remove the canary icon from the cache components docs: #85149
• Bump swc to v45: #85143
• [test] Fix test-dev with --projects: #85167
• [test] Update snapshots: #85171
• docs: mcp: #85010

Credits

Huge thanks to @eps1lon, @devjiwonchoi, @lukesandberg, @timneutkens, @ztanner, @acdlite, @mischnic, @bgw, @sebmarkbage, @wyattjoh, @gnoff, @huozhi, and @seeplusplus for helping!

Core Changes

• Upgrade React from 58bdc0bb-20251019 to f6a48828-20251019: #85081
• [devtools]: instrument client navigation hooks for suspense devtools: #85007
• Remove Segment from CacheNodeSeedData: #85080
• label as Prefetch/Prefetchable depending on prefetch config: #85076
• [cache components]: add 'bypass' cache indicator status: #85082
• Upgrade React from f6a48828-20251019 to 2bcbf254-20251020: #85112
• [cache components]: guard against setCacheStatus since its conditionally defined: #85125
• warn: add deprecation warning of eslint config: #85122
• add new devtools indicator loading state: #85083
• Await initial Flight response before hydrating: #85124
• fix(experimental.lockDistDir): Acquire the lock in dev earlier: #85116
• telemetry: mcp tool call: #85120
• [Turbopack] dedupe build errors: #85062

Misc Changes

• docs: experimentalClientMaxBodySize: #85105
• Docs: Add --debug-build-paths next build option: #85097
• Docs: Add note on tag limits for cacheTag: #85106
• docs: no switcher for TS only examples: #85109
• fix: Handle non-directory files in cache folder when performing cleanup: #84930
• Turbopack: Suggest using system certs when a TLS error occurs: #85009
• [turbopack] Try to fix v8 crashes on github actions: #85114
• docs: Update to Zod v4 syntax: #84807
• Docs: Add version history for next lint deprecation and update error message: #85100
• Turbopack: improve module evaluation name: #84633
• [test] Current behavior of dynamic APIs integration with React DevTools: #85111
• [Cache Components] fix env labels in perf track test: #85132

Credits

Huge thanks to @ztanner, @icyJoseph, @delbaoliveira, @acdlite, @lubieowoce, @bgw, @lukesandberg, @huozhi, @makandrr, @sokra, and @eps1lon for helping!

Core Changes

• Turbopack: Remove unneeded warning for telemetry: #85039
• [cache components] stabilize cacheLife profiles: #85050
• [cache components] show when cache components is enabled in the CLI: #85047
• [cache components]: show cache components enabled in DevTools: #85048
• [Cache Components] correctly label IO promises in devtools: #84928
• Plumbing for cache indicator: #84955
• Upgrade React from 93f85932-20251016 to 1324e1bb-20251016: #84999
• enable mcp server by default: #85058
• Add comment that we expect the function passed to bind to be anonymous: #85070
• Development: Addres comments on request log PR: #84945
• Development: Implement request time for Pages Router: #85012
• [cache components] add cache components indicator to dev start: #85069
• cli: build partial entries --debug-build-paths arg: #85052
• Turbopack: Better error for sassOptions.functions as it's unsupported: #85073

Misc Changes

• add a message about Turbopack tracing: #85044
• Turbopack: Implement next/font/local declarations option: #85051

Credits

Huge thanks to @sokra, @ztanner, @timneutkens, @lubieowoce, @eps1lon, @huozhi, and @sebmarkbage for helping!

Core Changes

• Add Activity name to route layouts and pages: #85011
• Update next-lint-to-eslint-cli to support FlatCompat.config: #85026
• [cache components]: move flag out of experimental: #85035
• [Cache Components] When caches are disabled in dev skip the cache warmup: #85014
• [Cache Components] Use canary React when only Cache Components is enabled: #85042

Misc Changes

• Turbopack: make tracing warning not fail build: #85032
• [ci]: increase number of runners for test jobs: #85049

Credits

Huge thanks to @acdlite, @devjiwonchoi, @mischnic, @ztanner, and @gnoff for helping!

Core Changes

• fix: incorrect canonicalUrl set when using output: export: #85019

Misc Changes

• Turbopack: shard amount need to grow quadratic to cpu count to keep propability of conflicts constant: #84921
• Turbopack: fix race condition when adding dependencies: #84946

Credits

Huge thanks to @sokra and @ztanner for helping!

Core Changes

• Add rendered search to router state: #84983
• [segment cache]: delay revalidation prefetch pings 300ms: #84981
• Show relative path from cwd for Proxy Middleware file conflict error: #84993
• [Cache Components] fix docs for cacheLife("seconds"): #85004
• Rename MiddlewareMatcher to ProxyMatcher: #85005
• [Breaking] Rename instrumentation onRequestError context.routeType from middleware to proxy: #85006
• [turbopack] Prevent accidental access to .next: #84714

Misc Changes

• Turbopack: Track errored tasks as dependency when using untracked(): #84914

Credits

Huge thanks to @sokra, @acdlite, @ztanner, @devjiwonchoi, @lubieowoce, and @lukesandberg for helping!