Replace flight navigation build id field with header #88855

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 header contains the BUILD_ID, keep the existing logic of storing the build id in the browser
output:export mode: a response field contains the BUILD_ID, keep the existing logic of storing the build id in the browser

Fallback behavior for when there is no deployment id
Fallback behavior for output: export
Find the right place where the header should be added for dynamic RSC responses on the server
Find the right place where the header should be added for prerendered static RSC responses (route manifest)

mischnic · 2026-01-21T14:38:15Z

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nextjs-bot · 2026-01-21T14:46:22Z

Failing test suites

Commit: 1cc781e | About building and testing Next.js

pnpm test-start-turbo test/e2e/app-dir/segment-cache/deployment-skew/deployment-skew.test.ts (turbopack) (job)

segment cache (deployment skew) > with NEXT_DEPLOYMENT_ID > does not crash when prefetching a static page on a different deployment (DD)

Expand output

● segment cache (deployment skew) › with NEXT_DEPLOYMENT_ID › does not crash when prefetching a static page on a different deployment

page.waitForSelector: Timeout 5000ms exceeded.
Call log:
  - waiting for locator('#build-id') 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 Playwright._chain (lib/browsers/playwright.ts:651:23)
  at Playwright._chain [as startChain] (lib/browsers/playwright.ts:632:17)
  at Playwright.startChain [as waitForElementByCss] (lib/browsers/playwright.ts:520:17)
  at Playwright.waitForElementByCss [as elementByCss] (lib/browsers/playwright.ts:405:17)
  at Playwright.elementByCss [as elementById] (lib/browsers/playwright.ts:425:17)
  at Object.elementById (e2e/app-dir/segment-cache/deployment-skew/deployment-skew.test.ts:122:37)

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

nextjs-bot · 2026-01-21T14:56:03Z

Stats from current PR

✅ No significant changes detected

📊 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)	456ms	455ms	✓	▁▁▁▁▁
Cold (Ready in log)	439ms	440ms	✓	▁▁▁▁▂
Cold (First Request)	801ms	809ms	✓	▁▁▃▁▃
Warm (Listen)	457ms	456ms	✓	▁▁▁▁▁
Warm (Ready in log)	439ms	440ms	✓	▁▁▁▁▁
Warm (First Request)	337ms	339ms	✓	▁▂▁▂▁

📦 Dev Server (Webpack) (Legacy)

📦 Dev Server (Webpack)

Metric	Canary	PR	Change	Trend
Cold (Listen)	455ms	455ms	✓	▁▁▁▁▁
Cold (Ready in log)	439ms	439ms	✓	▁▁▁▁▁
Cold (First Request)	1.767s	1.761s	✓	▁▁▁▁▁
Warm (Listen)	456ms	456ms	✓	▁▁▁▁▁
Warm (Ready in log)	439ms	439ms	✓	▁▁▁▁▁
Warm (First Request)	1.764s	1.775s	✓	▁▁▁▁▁

⚡ Production Builds

Metric	Canary	PR	Change	Trend
Fresh Build	4.304s	4.273s	✓	▂▂▁▁▁
Cached Build	4.311s	4.319s	✓	▂▂▁▁▁

📦 Production Builds (Webpack) (Legacy)

📦 Production Builds (Webpack)

Metric	Canary	PR	Change	Trend
Fresh Build	14.089s	14.030s	✓	▁▆▃▄▂
Cached Build	14.283s	14.233s	✓	▁▇▃▄▄
node_modules Size	460 MB	460 MB	✓	▁▁▁▁▁

📦 Bundle Sizes

Bundle Sizes

⚡ Turbopack

Client

Main Bundles: **432 kB** → **432 kB** ⚠️ +14 B

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

Server

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	764 B	760 B	✓
Total	764 B	760 B	✅ -4 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	451 B	450 B	✓
Total	451 B	450 B	✅ -1 B

📦 Webpack

Client

Main Bundles

	Canary	PR	Change
2086.HASH.js gzip	169 B	N/A	-
2161-HASH.js gzip	5.41 kB	N/A	-
2747-HASH.js gzip	4.48 kB	N/A	-
4322-HASH.js gzip	52.7 kB	N/A	-
ec793fe8-HASH.js gzip	62.3 kB	N/A	-
framework-HASH.js gzip	59.8 kB	59.8 kB	✓
main-app-HASH.js gzip	251 B	253 B	✓
main-HASH.js gzip	38.7 kB	39.1 kB	✓
webpack-HASH.js gzip	1.68 kB	1.68 kB	✓
1596.HASH.js gzip	N/A	169 B	-
2658-HASH.js gzip	N/A	52.5 kB	-
6349-HASH.js gzip	N/A	4.46 kB	-
7019-HASH.js gzip	N/A	5.43 kB	-
b17a3386-HASH.js gzip	N/A	62.3 kB	-
Total	226 kB	226 kB	⚠️ +135 B

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	193 B	✓
_error-HASH.js gzip	182 B	182 B	✓
css-HASH.js gzip	336 B	335 B	✓
dynamic-HASH.js gzip	1.8 kB	1.8 kB	✓
edge-ssr-HASH.js gzip	256 B	256 B	✓
head-HASH.js gzip	352 B	349 B	✓
hooks-HASH.js gzip	385 B	384 B	✓
image-HASH.js gzip	580 B	580 B	✓
index-HASH.js gzip	259 B	258 B	✓
link-HASH.js gzip	2.5 kB	2.51 kB	✓
routerDirect..HASH.js gzip	319 B	317 B	✓
script-HASH.js gzip	385 B	387 B	✓
withRouter-HASH.js gzip	316 B	315 B	✓
1afbb74e6ecf..834.css gzip	106 B	106 B	✓
Total	7.97 kB	7.96 kB	✅ -8 B

Server

Edge SSR

	Canary	PR	Change
edge-ssr.js gzip	125 kB	125 kB	✓
page.js gzip	243 kB	239 kB	🟢 4.76 kB (-2%)
Total	368 kB	363 kB	✅ -4.74 kB

Middleware

	Canary	PR	Change
middleware-b..fest.js gzip	617 B	616 B	✓
middleware-r..fest.js gzip	155 B	156 B	✓
middleware.js gzip	32.9 kB	33.3 kB	🔴 +356 B (+1%)
edge-runtime..pack.js gzip	842 B	842 B	✓
Total	34.5 kB	34.9 kB	⚠️ +356 B

Build Details

Build Manifests

	Canary	PR	Change
_buildManifest.js gzip	738 B	738 B	✓
Total	738 B	738 B	✓

Build Cache

	Canary	PR	Change
0.pack gzip	3.69 MB	3.69 MB	🔴 +6.44 kB (+0%)
index.pack gzip	102 kB	102 kB	✓
index.pack.old gzip	100 kB	102 kB	🔴 +1.43 kB (+1%)
Total	3.89 MB	3.9 MB	⚠️ +7.83 kB

🔄 Shared (bundler-independent)

Runtimes

	Canary	PR	Change
app-page-exp...dev.js gzip	305 kB	306 kB	✓
app-page-exp..prod.js gzip	162 kB	162 kB	✓
app-page-tur...dev.js gzip	305 kB	305 kB	✓
app-page-tur..prod.js gzip	162 kB	162 kB	✓
app-page-tur...dev.js gzip	302 kB	302 kB	✓
app-page-tur..prod.js gzip	160 kB	160 kB	✓
app-page.run...dev.js gzip	302 kB	302 kB	✓
app-page.run..prod.js gzip	160 kB	160 kB	✓
app-route-ex...dev.js gzip	68.8 kB	68.8 kB	✓
app-route-ex..prod.js gzip	47.6 kB	47.6 kB	✓
app-route-tu...dev.js gzip	68.8 kB	68.8 kB	✓
app-route-tu..prod.js gzip	47.6 kB	47.6 kB	✓
app-route-tu...dev.js gzip	68.4 kB	68.4 kB	✓
app-route-tu..prod.js gzip	47.4 kB	47.4 kB	✓
app-route.ru...dev.js gzip	68.4 kB	68.4 kB	✓
app-route.ru..prod.js gzip	47.4 kB	47.4 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	41.2 kB	41.2 kB	✓
pages-api-tu..prod.js gzip	31.3 kB	31.3 kB	✓
pages-api.ru...dev.js gzip	41.1 kB	41.1 kB	✓
pages-api.ru..prod.js gzip	31.2 kB	31.2 kB	✓
pages-turbo....dev.js gzip	50.8 kB	50.8 kB	✓
pages-turbo...prod.js gzip	38.2 kB	38.2 kB	✓
pages.runtim...dev.js gzip	50.8 kB	50.8 kB	✓
pages.runtim..prod.js gzip	38.2 kB	38.2 kB	✓
server.runti..prod.js gzip	62.2 kB	62.2 kB	✓
Total	2.71 MB	2.71 MB	⚠️ +751 B

📝 Changed Files (8 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

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

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

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

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

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app-page.runtime.prod.js

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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 5.89%

⚡ 1 improved benchmark
✅ 16 untouched benchmarks
⏩ 3 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	Simulation	`react-dom-client.development.js[tracing]`	395 ms	373 ms	+5.89%

_{Comparing mischnic/flight-nav-requests-build-id (f2a1392) with canary (d4e64f5)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/flight-nav-tests (19ad6a7) during the generation of this report, so canary (d4e64f5) 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

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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

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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

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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 added 7 commits January 23, 2026 10:18

Replace flight navigation build id field with header

1828b8b

Cleanup

c7c146b

pivot

06104cb

pivot

aa80f72

fixup

e961a0a

WIP test

8dfa939

WIP debug

5868f1f

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

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Replace flight navigation build id field with header #88855

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Merging this PR will improve performance by 5.89%

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