Replace flight navigation build id field with header by mischnic · Pull Request #88855 · vercel/next.js

mischnic · 2026-01-21T14:37:46Z

with deployment id available: a header contains the process.env.NEXT_DEPLOYMENT_ID , the client knows its dpl id already, so we can use that already
with deployment id unavailable: a response field contains the BUILD_ID, keep the existing logic of storing the build id in the browser

It's unfortunate that we have to keep the BUILD_ID response field approach as a fallback, but oh well.
This has the benefit that we won't need the build id anymore when the deployment id is available.

If you use output:export and set config.deploymentId (i.e. enable skew protection) you are still expected to set these headers.

Fallback behavior for when there is no deployment id
Run deployment tests

mischnic · 2026-01-21T14:38:15Z

Replace flight navigation build id field with header #88855 : 2 dependent PRs (#89112 , #89325 ) 👈 (View in Graphite)
canary

This stack of pull requests is managed by Graphite. Learn more about stacking.

nextjs-bot · 2026-01-21T14:46:22Z

Failing test suites

Commit: b47ffc0 | About building and testing Next.js

pnpm test-deploy test/e2e/app-dir/app-client-cache/client-cache.original.test.ts (job)

app dir client cache semantics (30s/5min) > prefetch={undefined} - default > should refetch the full page after 5 mins (DD)

Expand output

● app dir client cache semantics (30s/5min) › prefetch={undefined} - default › should refetch the full page after 5 mins

page.waitForSelector: Timeout 10000ms exceeded.
Call log:
  - waiting for locator('#loading') to be visible

  519 |
  520 |     return this.startChain(async () => {
> 521 |       const el = await page.waitForSelector(selector, {
      |                             ^
  522 |         timeout,
  523 |         state,
  524 |       })

  at waitForSelector (lib/browsers/playwright.ts:521:29)
  at Object.<anonymous> (e2e/app-dir/app-client-cache/client-cache.original.test.ts:387:34)
  at Proxy._chain (lib/browsers/playwright.ts:651:23)
  at Proxy._chain (lib/browsers/playwright.ts:632:17)
  at Proxy.startChain (lib/browsers/playwright.ts:520:17)
  at Object.waitForElementByCss (e2e/app-dir/app-client-cache/client-cache.original.test.ts:390:12)
  at Proxy._chain (lib/browsers/playwright.ts:651:23)
  at Proxy._chain (lib/browsers/playwright.ts:627:17)
  at Proxy.continueChain (lib/browsers/playwright.ts:433:17)
  at Object.text (e2e/app-dir/app-client-cache/client-cache.original.test.ts:391:12)

pnpm test-deploy test/e2e/app-dir/trailingslash/trailingslash.test.ts (job)

app-dir trailingSlash handling > should revalidate a page with generated static params (withSlash=false) (DD)

Expand output

● app-dir trailingSlash handling › should revalidate a page with generated static params (withSlash=false)

expect(received).toBe(expected) // Object.is equality

Expected: "2026-02-03T13:06:22.058Z"
Received: "2026-02-03T13:06:47.101Z"

  82 |           .text()
  83 |
> 84 |         expect(refreshedGeneratedAt).toBe(initialGeneratedAt)
     |                                      ^
  85 |       }
  86 |
  87 |       await browser

  at toBe (e2e/app-dir/trailingslash/trailingslash.test.ts:84:38)

packages/next/src/client/components/segment-cache/cache.ts

nextjs-bot · 2026-01-21T14:56:03Z

Stats from current PR

🔴 1 regression

Metric	Canary	PR	Change	Trend
node_modules Size	464 MB	464 MB	🔴 +60.5 kB (+0%)	▁▁▁▁▁

📊 All Metrics

📖 Metrics Glossary

Dev Server Metrics:

Listen = TCP port starts accepting connections
First Request = HTTP server returns successful response
Cold = Fresh build (no cache)
Warm = With cached build artifacts

Build Metrics:

Fresh = Clean build (no .next directory)
Cached = With existing .next directory

Change Thresholds:

Time: Changes < 50ms AND < 10%, OR < 2% are insignificant
Size: Changes < 1KB AND < 1% are insignificant
All other changes are flagged to catch regressions

⚡ Dev Server

Metric	Canary	PR	Change	Trend
Cold (Listen)	506ms	506ms	✓	▁▁▁▁▁
Cold (Ready in log)	460ms	460ms	✓	▂▂▂▂▁
Cold (First Request)	856ms	867ms	✓	▅▅▅▄▁
Warm (Listen)	457ms	504ms	✓	▁▁▁▁▁
Warm (Ready in log)	459ms	459ms	✓	▁▁▁▁▁
Warm (First Request)	365ms	329ms	✓	▁▁▂▂▁

📦 Dev Server (Webpack) (Legacy)

📦 Dev Server (Webpack)

Metric	Canary	PR	Change	Trend
Cold (Listen)	455ms	455ms	✓	▁█▅▅█
Cold (Ready in log)	439ms	437ms	✓	▇▆█▇█
Cold (First Request)	1.856s	1.842s	✓	▄▃▅▄▆
Warm (Listen)	455ms	456ms	✓	▅▅▅▅█
Warm (Ready in log)	439ms	437ms	✓	▇▆▆▆█
Warm (First Request)	1.872s	1.871s	✓	▅▄▆▄▇

⚡ Production Builds

Metric	Canary	PR	Change	Trend
Fresh Build	4.369s	4.406s	✓	▁▁▁▁▃
Cached Build	4.400s	4.474s	✓	▁▁▁▁▃

📦 Production Builds (Webpack) (Legacy)

📦 Production Builds (Webpack)

Metric	Canary	PR	Change	Trend
Fresh Build	13.774s	13.854s	✓	▁▁▃▁▅
Cached Build	13.889s	13.925s	✓	▁▁▃▁▅
node_modules Size	464 MB	464 MB	🔴 +60.5 kB (+0%)	▁▁▁▁▁

📦 Bundle Sizes

Bundle Sizes

⚡ Turbopack

Client

Main Bundles: **434 kB** → **437 kB** ⚠️ +2.23 kB

81 files with content-based hashes (individual files not comparable between builds)

Server

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	763 B	760 B	✓
Total	763 B	760 B	✅ -3 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	449 B	452 B	✓
Total	449 B	452 B	⚠️ +3 B

📦 Webpack

Client

Main Bundles

	Canary	PR	Change
5528-HASH.js gzip	5.47 kB	N/A	-
6280-HASH.js gzip	54.5 kB	N/A	-
6335.HASH.js gzip	169 B	N/A	-
912-HASH.js gzip	4.53 kB	N/A	-
e8aec2e4-HASH.js gzip	62.5 kB	N/A	-
framework-HASH.js gzip	59.7 kB	59.7 kB	✓
main-app-HASH.js gzip	255 B	253 B	✓
main-HASH.js gzip	39 kB	39 kB	✓
webpack-HASH.js gzip	1.68 kB	1.68 kB	✓
262-HASH.js gzip	N/A	4.52 kB	-
2889.HASH.js gzip	N/A	169 B	-
5602-HASH.js gzip	N/A	5.48 kB	-
6948ada0-HASH.js gzip	N/A	62.5 kB	-
9544-HASH.js gzip	N/A	57.4 kB	-
Total	228 kB	231 kB	⚠️ +2.9 kB

Polyfills

	Canary	PR	Change
polyfills-HASH.js gzip	39.4 kB	39.4 kB	✓
Total	39.4 kB	39.4 kB	✓

Pages

	Canary	PR	Change
_app-HASH.js gzip	194 B	194 B	✓
_error-HASH.js gzip	183 B	180 B	🟢 3 B (-2%)
css-HASH.js gzip	331 B	330 B	✓
dynamic-HASH.js gzip	1.81 kB	1.81 kB	✓
edge-ssr-HASH.js gzip	256 B	256 B	✓
head-HASH.js gzip	351 B	352 B	✓
hooks-HASH.js gzip	384 B	383 B	✓
image-HASH.js gzip	580 B	581 B	✓
index-HASH.js gzip	260 B	260 B	✓
link-HASH.js gzip	2.49 kB	2.49 kB	✓
routerDirect..HASH.js gzip	320 B	319 B	✓
script-HASH.js gzip	386 B	386 B	✓
withRouter-HASH.js gzip	315 B	315 B	✓
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Total	7.97 kB	7.97 kB	✅ -1 B

Server

Edge SSR

	Canary	PR	Change
edge-ssr.js gzip	126 kB	126 kB	✓
page.js gzip	249 kB	249 kB	✓
Total	375 kB	375 kB	⚠️ +229 B

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	616 B	614 B	✓
middleware-r..fest.js gzip	156 B	155 B	✓
middleware.js gzip	33.3 kB	33.1 kB	✓
edge-runtime..pack.js gzip	842 B	842 B	✓
Total	34.9 kB	34.8 kB	✅ -159 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	732 B	736 B	✓
Total	732 B	736 B	⚠️ +4 B

Build Cache

	Canary	PR	Change
0.pack gzip	3.8 MB	3.82 MB	🔴 +27.2 kB (+1%)
index.pack gzip	103 kB	103 kB	✓
index.pack.old gzip	102 kB	102 kB	✓
Total	4 MB	4.03 MB	⚠️ +27.5 kB

🔄 Shared (bundler-independent)

Runtimes

	Canary	PR	Change
app-page-exp...dev.js gzip	311 kB	312 kB	✓
app-page-exp..prod.js gzip	166 kB	166 kB	✓
app-page-tur...dev.js gzip	311 kB	311 kB	✓
app-page-tur..prod.js gzip	166 kB	166 kB	✓
app-page-tur...dev.js gzip	308 kB	308 kB	✓
app-page-tur..prod.js gzip	164 kB	164 kB	✓
app-page.run...dev.js gzip	308 kB	308 kB	✓
app-page.run..prod.js gzip	164 kB	164 kB	✓
app-route-ex...dev.js gzip	70.4 kB	70.4 kB	✓
app-route-ex..prod.js gzip	48.9 kB	48.9 kB	✓
app-route-tu...dev.js gzip	70.4 kB	70.4 kB	✓
app-route-tu..prod.js gzip	49 kB	49 kB	✓
app-route-tu...dev.js gzip	70 kB	70 kB	✓
app-route-tu..prod.js gzip	48.7 kB	48.7 kB	✓
app-route.ru...dev.js gzip	70 kB	70 kB	✓
app-route.ru..prod.js gzip	48.7 kB	48.7 kB	✓
dist_client_...dev.js gzip	324 B	324 B	✓
dist_client_...dev.js gzip	326 B	326 B	✓
dist_client_...dev.js gzip	318 B	318 B	✓
dist_client_...dev.js gzip	317 B	317 B	✓
pages-api-tu...dev.js gzip	43.1 kB	43.2 kB	✓
pages-api-tu..prod.js gzip	32.9 kB	32.9 kB	✓
pages-api.ru...dev.js gzip	43.1 kB	43.1 kB	✓
pages-api.ru..prod.js gzip	32.8 kB	32.8 kB	✓
pages-turbo....dev.js gzip	52.4 kB	52.4 kB	✓
pages-turbo...prod.js gzip	39.4 kB	39.4 kB	✓
pages.runtim...dev.js gzip	52.4 kB	52.4 kB	✓
pages.runtim..prod.js gzip	39.3 kB	39.3 kB	✓
server.runti..prod.js gzip	62.6 kB	62.6 kB	✓
Total	2.77 MB	2.78 MB	⚠️ +1.45 kB

📝 Changed Files (16 files)

Files with changes:

app-page-exp..ntime.dev.js
app-page-exp..time.prod.js
app-page-tur..ntime.dev.js
app-page-tur..time.prod.js
app-page-tur..ntime.dev.js
app-page-tur..time.prod.js
app-page.runtime.dev.js
app-page.runtime.prod.js
app-route-ex..ntime.dev.js
app-route-tu..ntime.dev.js
app-route-tu..ntime.dev.js
app-route.runtime.dev.js
pages-api-tu..ntime.dev.js
pages-api.runtime.dev.js
pages-turbo...ntime.dev.js
pages.runtime.dev.js

View diffs

app-page-exp..ntime.dev.js

failed to diff

app-page-exp..time.prod.js

failed to diff

app-page-tur..ntime.dev.js

failed to diff

app-page-tur..time.prod.js

failed to diff

app-page-tur..ntime.dev.js

failed to diff

app-page-tur..time.prod.js

failed to diff

app-page.runtime.dev.js

failed to diff

app-page.runtime.prod.js

failed to diff

app-route-ex..ntime.dev.js

Diff too large to display

app-route-tu..ntime.dev.js

Diff too large to display

app-route-tu..ntime.dev.js

Diff too large to display

app-route.runtime.dev.js

Diff too large to display

pages-api-tu..ntime.dev.js

Diff too large to display

pages-api.runtime.dev.js

Diff too large to display

pages-turbo...ntime.dev.js

Diff too large to display

pages.runtime.dev.js

Diff too large to display

packages/next/src/client/app-index.tsx

packages/next/src/client/components/router-reducer/fetch-server-response.ts

packages/next/src/client/components/segment-cache/cache.ts

codspeed-hq · 2026-01-22T16:35:44Z

Merging this PR will improve performance by 6.41%

⚡ 3 improved benchmarks
✅ 14 untouched benchmarks
⏩ 3 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	Simulation	`packages-bundle.js[full]`	1,051.9 ms	999.1 ms	+5.28%
⚡	Simulation	`app-page-turbo.runtime.prod.js[tracing]`	594.4 ms	571.2 ms	+4.06%
⚡	Simulation	`app-page-turbo.runtime.prod.js[full]`	696 ms	654.1 ms	+6.41%

_{Comparing mischnic/flight-nav-requests-build-id (e0e23b6) with canary (bb41cbd)²}

3 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩
No successful run was found on mischnic/reapply-pages-buildid (eaf3516) during the generation of this report, so canary (bb41cbd) was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

nextjs-bot added created-by: Turbopack team PRs by the Turbopack team. type: next labels Jan 21, 2026

mischnic changed the title ~~Cleanup~~ Replace flight navigation build id field with header Jan 21, 2026

vercel bot reviewed Jan 21, 2026

View reviewed changes

packages/next/src/client/components/segment-cache/cache.ts Outdated Show resolved Hide resolved

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 51a1d88 to 59cd614 Compare January 21, 2026 15:12

nextjs-bot added the tests label Jan 21, 2026

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 59cd614 to cdd8a84 Compare January 21, 2026 16:11

vercel bot reviewed Jan 21, 2026

View reviewed changes

packages/next/src/client/app-index.tsx Outdated Show resolved Hide resolved

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from cdd8a84 to b6db6a5 Compare January 21, 2026 16:27

mischnic changed the base branch from canary to graphite-base/88855 January 22, 2026 16:14

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 0fb4730 to f2a1392 Compare January 22, 2026 16:14

mischnic changed the base branch from graphite-base/88855 to mischnic/flight-nav-tests January 22, 2026 16:14

mischnic mentioned this pull request Jan 22, 2026

Fix chunk loading when using __turbopack_load_by_url__ with query #88899

Merged

vercel bot reviewed Jan 22, 2026

View reviewed changes

packages/next/src/client/components/router-reducer/fetch-server-response.ts Outdated Show resolved Hide resolved

packages/next/src/client/components/segment-cache/cache.ts Outdated Show resolved Hide resolved

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from f2a1392 to 1cc781e Compare January 22, 2026 16:21

mischnic changed the base branch from mischnic/flight-nav-tests to graphite-base/88855 January 23, 2026 09:13

mischnic force-pushed the graphite-base/88855 branch from 19ad6a7 to 0a673e6 Compare January 23, 2026 09:19

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 1cc781e to 5868f1f Compare January 23, 2026 09:19

mischnic changed the base branch from graphite-base/88855 to mischnic/flight-nav-tests January 23, 2026 09:19

mischnic changed the base branch from mischnic/flight-nav-tests to graphite-base/88855 January 23, 2026 10:30

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 5868f1f to 463e3ff Compare January 23, 2026 13:31

mischnic force-pushed the graphite-base/88855 branch from 0a673e6 to aea4100 Compare January 23, 2026 13:31

mischnic changed the base branch from graphite-base/88855 to mischnic/flight-nav-tests January 23, 2026 13:31

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch 3 times, most recently from bc8aee0 to 9e938e0 Compare January 24, 2026 08:39

mischnic requested review from acdlite and ijjk January 28, 2026 10:38

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from cad2c36 to d5ca54e Compare January 29, 2026 08:55

mischnic force-pushed the mischnic/pages-data-route-dpl-header branch 2 times, most recently from 52e5424 to 95784fd Compare January 29, 2026 10:52

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch 2 times, most recently from 685d815 to e240cec Compare January 29, 2026 13:24

mischnic force-pushed the mischnic/pages-data-route-dpl-header branch 2 times, most recently from c9626ed to 9455b94 Compare January 29, 2026 13:35

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch 2 times, most recently from 4aa0a2d to df56610 Compare January 29, 2026 13:59

mischnic force-pushed the mischnic/pages-data-route-dpl-header branch from 9455b94 to 646bac7 Compare January 29, 2026 13:59

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from df56610 to 06dcfd5 Compare January 29, 2026 14:03

mischnic force-pushed the mischnic/pages-data-route-dpl-header branch from 646bac7 to ac6933c Compare January 30, 2026 11:40

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from 06dcfd5 to fed758a Compare January 30, 2026 11:40

timneutkens approved these changes Jan 30, 2026

View reviewed changes

mischnic changed the base branch from mischnic/pages-data-route-dpl-header to graphite-base/88855 January 30, 2026 17:22

mischnic force-pushed the graphite-base/88855 branch from ac6933c to 6766a27 Compare January 30, 2026 17:26

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from fed758a to a595e10 Compare January 30, 2026 17:26

mischnic changed the base branch from graphite-base/88855 to canary January 30, 2026 17:27

mischnic changed the base branch from canary to graphite-base/88855 January 30, 2026 23:06

mischnic force-pushed the mischnic/flight-nav-requests-build-id branch from a595e10 to e0e23b6 Compare January 30, 2026 23:07

mischnic changed the base branch from graphite-base/88855 to mischnic/reapply-pages-buildid January 30, 2026 23:07

mischnic mentioned this pull request Jan 30, 2026

Handle Pages data route skew with deployment id header, take 2 #89325

Merged

mischnic added 3 commits February 3, 2026 10:12

Replace flight navigation build id field with header

62fb5f8

add header

48a91cc

header test

7768172

mischnic changed the base branch from mischnic/reapply-pages-buildid to graphite-base/88855 February 3, 2026 09:13

fixup tests

b47ffc0

mischnic mentioned this pull request Feb 5, 2026

Proper e2e test of function determinism - adapter #89522

Merged

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Replace flight navigation build id field with header#88855

Replace flight navigation build id field with header#88855
mischnic merged 4 commits intocanaryfrom
mischnic/flight-nav-requests-build-id

mischnic commented Jan 21, 2026 •

edited

Loading

Uh oh!

mischnic commented Jan 21, 2026 •

edited

Loading

Uh oh!

nextjs-bot commented Jan 21, 2026 •

edited

Loading

Uh oh!

Uh oh!

nextjs-bot commented Jan 21, 2026 •

edited

Loading

⚡ Dev Server

📦 Dev Server (Webpack)

⚡ Production Builds

📦 Production Builds (Webpack)

Bundle Sizes

⚡ Turbopack

📦 Webpack

🔄 Shared (bundler-independent)

Uh oh!

Uh oh!

Uh oh!

Uh oh!

codspeed-hq bot commented Jan 22, 2026 •

edited

Loading

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

mischnic commented Jan 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

mischnic commented Jan 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

nextjs-bot commented Jan 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Failing test suites

Uh oh!

Uh oh!

nextjs-bot commented Jan 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Stats from current PR

🔴 1 regression

⚡ Dev Server

📦 Dev Server (Webpack)

⚡ Production Builds

📦 Production Builds (Webpack)

Bundle Sizes

⚡ Turbopack

📦 Webpack

🔄 Shared (bundler-independent)

Uh oh!

Uh oh!

Uh oh!

Uh oh!

codspeed-hq bot commented Jan 22, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Merging this PR will improve performance by 6.41%

Performance Changes

Footnotes

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

mischnic commented Jan 21, 2026 •

edited

Loading

mischnic commented Jan 21, 2026 •

edited

Loading

nextjs-bot commented Jan 21, 2026 •

edited

Loading

nextjs-bot commented Jan 21, 2026 •

edited

Loading

codspeed-hq bot commented Jan 22, 2026 •

edited

Loading