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test(next): cover HMR rebuild convergence - #3471

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test(next): cover HMR rebuild convergence#3471
NathanColosimo wants to merge 4 commits into
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@NathanColosimo

@NathanColosimo NathanColosimo commented Aug 11, 2026 •
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Summary

  • make expected hot, full, and skipped rebuild counts explicit
  • verify body-only edits stay hot while import, add, and remove changes rediscover workflows
  • verify editing an imported dependency updates workflow execution on stable and canary Next.js
  • test Next.js 16.3.1 and 16.3.1-canary.21 across Turbopack, webpack, Node.js, and QuickJS

Testing

  • pnpm --filter @workflow/next build
  • pnpm --filter @workflow/next test
  • focused local Next.js 16.3.1-canary.21 HMR scenario with Turbopack and webpack
  • GitHub Actions Next.js local-development matrix

Stack

  1. fix(next): converge workflow HMR rebuilds #3333: rebuild convergence and unit coverage
  2. fix(next): watch before initial build #3470: close the startup observation gap
  3. This PR: stable/canary end-to-end HMR coverage

Stack created with GitHub Stacks CLI • Give Feedback 💬

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changeset-bot Bot commented Aug 11, 2026 •
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⚠️ No Changeset found

Latest commit: cb7857d

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

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@github-actions

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🧪 E2E Test Results

✅ All tests passed

⚠️ Flaky E2E Tests (passed on retry)

These tests failed at least once and passed on a retry. A recurring entry here is a real race worth investigating.

  • addTenWorkflow via pages router (nextjs-webpack)
  • parallelStepsThenWebhookWorkflow - no hook_conflict from same-tick replay race (vite)

🛠 Infra Events (absorbed by the harness)

Platform anomalies the e2e harness detected and worked around (e.g. a run the queue never picked up, replaced by a fresh run). Clustered timestamps indicate a backend blip; a steady drip indicates a platform issue worth escalating.

  • run-pickup-stall · addTenWorkflow (tanstack-start) · at 19:09:32Z · abandoned wrun_01M08J1KF9JDBP110FMZ4FYSNV

E2E Test Summary

Summary
Passed Failed Skipped Total
✅ ▲ Vercel Production 3474 0 738 4212
✅ 💻 Local Development 3810 0 558 4368
✅ 📦 Local Production 3810 0 558 4368
✅ 🐘 Local Postgres 3810 0 558 4368
✅ 🪟 Windows 312 0 0 312
✅ 🌐 Cross-language Conformance 9 0 128 137
✅ vercel-multi-region 27 0 0 27
Total 15252 0 2540 17792
Details by Category

✅ ▲ Vercel Production

App Passed Failed Skipped
✅ astro-node 128 0 28
✅ astro-quickjs 128 0 28
✅ example-node 128 0 28
✅ example-quickjs 128 0 28
✅ express-node 128 0 28
✅ express-quickjs 128 0 28
✅ fastify-node 128 0 28
✅ fastify-quickjs 128 0 28
✅ hono-node 128 0 28
✅ hono-quickjs 128 0 28
✅ nest-node 128 0 28
✅ nest-quickjs 128 0 28
✅ nextjs-turbopack-node 153 0 3
✅ nextjs-turbopack-quickjs 153 0 3
✅ nextjs-webpack-node 153 0 3
✅ nextjs-webpack-quickjs 153 0 3
✅ nitro-node 128 0 28
✅ nitro-quickjs 128 0 28
✅ nuxt-node 128 0 28
✅ nuxt-quickjs 128 0 28
✅ python-node 8 0 148
✅ sveltekit-node 147 0 9
✅ sveltekit-quickjs 147 0 9
✅ tanstack-start-node 128 0 28
✅ tanstack-start-quickjs 128 0 28
✅ vite-node 128 0 28
✅ vite-quickjs 128 0 28

✅ 💻 Local Development

App Passed Failed Skipped
✅ astro-stable-node 130 0 26
✅ astro-stable-quickjs 130 0 26
✅ express-stable-node 130 0 26
✅ express-stable-quickjs 130 0 26
✅ fastify-stable-node 130 0 26
✅ fastify-stable-quickjs 130 0 26
✅ hono-stable-node 130 0 26
✅ hono-stable-quickjs 130 0 26
✅ nest-stable-node 130 0 26
✅ nest-stable-quickjs 130 0 26
✅ nextjs-turbopack-canary-node 137 0 19
✅ nextjs-turbopack-canary-quickjs 137 0 19
✅ nextjs-turbopack-stable-node 156 0 0
✅ nextjs-turbopack-stable-quickjs 156 0 0
✅ nextjs-webpack-canary-node 137 0 19
✅ nextjs-webpack-canary-quickjs 137 0 19
✅ nextjs-webpack-stable-node 156 0 0
✅ nextjs-webpack-stable-quickjs 156 0 0
✅ nitro-stable-node 130 0 26
✅ nitro-stable-quickjs 130 0 26
✅ nuxt-stable-node 130 0 26
✅ nuxt-stable-quickjs 130 0 26
✅ sveltekit-stable-node 149 0 7
✅ sveltekit-stable-quickjs 149 0 7
✅ tanstack-start-node 130 0 26
✅ tanstack-start-quickjs 130 0 26
✅ vite-stable-node 130 0 26
✅ vite-stable-quickjs 130 0 26

✅ 📦 Local Production

App Passed Failed Skipped
✅ astro-stable-node 130 0 26
✅ astro-stable-quickjs 130 0 26
✅ express-stable-node 130 0 26
✅ express-stable-quickjs 130 0 26
✅ fastify-stable-node 130 0 26
✅ fastify-stable-quickjs 130 0 26
✅ hono-stable-node 130 0 26
✅ hono-stable-quickjs 130 0 26
✅ nest-stable-node 130 0 26
✅ nest-stable-quickjs 130 0 26
✅ nextjs-turbopack-canary-node 137 0 19
✅ nextjs-turbopack-canary-quickjs 137 0 19
✅ nextjs-turbopack-stable-node 156 0 0
✅ nextjs-turbopack-stable-quickjs 156 0 0
✅ nextjs-webpack-canary-node 137 0 19
✅ nextjs-webpack-canary-quickjs 137 0 19
✅ nextjs-webpack-stable-node 156 0 0
✅ nextjs-webpack-stable-quickjs 156 0 0
✅ nitro-stable-node 130 0 26
✅ nitro-stable-quickjs 130 0 26
✅ nuxt-stable-node 130 0 26
✅ nuxt-stable-quickjs 130 0 26
✅ sveltekit-stable-node 149 0 7
✅ sveltekit-stable-quickjs 149 0 7
✅ tanstack-start-node 130 0 26
✅ tanstack-start-quickjs 130 0 26
✅ vite-stable-node 130 0 26
✅ vite-stable-quickjs 130 0 26

✅ 🐘 Local Postgres

App Passed Failed Skipped
✅ astro-stable-node 130 0 26
✅ astro-stable-quickjs 130 0 26
✅ express-stable-node 130 0 26
✅ express-stable-quickjs 130 0 26
✅ fastify-stable-node 130 0 26
✅ fastify-stable-quickjs 130 0 26
✅ hono-stable-node 130 0 26
✅ hono-stable-quickjs 130 0 26
✅ nest-stable-node 130 0 26
✅ nest-stable-quickjs 130 0 26
✅ nextjs-turbopack-canary-node 137 0 19
✅ nextjs-turbopack-canary-quickjs 137 0 19
✅ nextjs-turbopack-stable-node 156 0 0
✅ nextjs-turbopack-stable-quickjs 156 0 0
✅ nextjs-webpack-canary-node 137 0 19
✅ nextjs-webpack-canary-quickjs 137 0 19
✅ nextjs-webpack-stable-node 156 0 0
✅ nextjs-webpack-stable-quickjs 156 0 0
✅ nitro-stable-node 130 0 26
✅ nitro-stable-quickjs 130 0 26
✅ nuxt-stable-node 130 0 26
✅ nuxt-stable-quickjs 130 0 26
✅ sveltekit-stable-node 149 0 7
✅ sveltekit-stable-quickjs 149 0 7
✅ tanstack-start-node 130 0 26
✅ tanstack-start-quickjs 130 0 26
✅ vite-stable-node 130 0 26
✅ vite-stable-quickjs 130 0 26

✅ 🪟 Windows

App Passed Failed Skipped
✅ nextjs-turbopack-node 156 0 0
✅ nextjs-turbopack-quickjs 156 0 0

✅ 🌐 Cross-language Conformance

App Passed Failed Skipped
✅ python 9 0 128

✅ vercel-multi-region

App Passed Failed Skipped
✅ nextjs-turbopack 27 0 0

📋 View full workflow run

@vercel

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The latest updates on your projects. Learn more about Vercel for GitHub.

Project Deployment Actions Updated (UTC)
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📊 Workflow Benchmarks

commit cb7857d · Mon, 17 Aug 2026 19:25:41 GMT · run logs

Backend: vercel · app: nextjs-turbopack

Metric Scenario Best (ms) P75 (ms) P90 (ms) P99 (ms) Samples
TTFS step 228 (-70%) 💚 1391 🔴 (+24%) 🔻 1407 🔴 (+17%) 🔻 1768 🔴 (+15%) 30
TTFS stream 241 (-76%) 💚 1429 🔴 (+33%) 🔻 1451 🔴 (+33%) 🔻 1531 🔴 (+33%) 🔻 30
TTFS hook + stream 393 (-69%) 💚 1781 🔴 (+25%) 🔻 1892 🔴 (+26%) 🔻 6043 🔴 (+185%) 🔻 30
Fan-out TTFS Promise.all(100 steps) 1230 (+2.7%) 2959 (+31%) 🔻 3157 (+33%) 🔻 3528 (+34%) 🔻 10
Fan-out TTLS Promise.all(100 steps) 6747 (+11%) 8860 (+7.1%) 9540 (+13%) 9945 (+6.3%) 10
STSO 1020 steps (inline) 141 (+17%) 🔻 268 (+14%) 306 (+14%) 488 (+14%) 1019
WO 1020 steps 257463 (+16%) 🔻 257463 (+16%) 🔻 257463 (+16%) 🔻 257463 (+16%) 🔻 1
CRTT first chunk (pooled) 95 (+8.0%) 168 (+14%) 237 (+35%) 🔻 259 (-49%) 💚 28

Streams

Scenario wr c/s rd c/s wr KiB/s rd KiB/s CRTT 1st p75 p90 p99 CDV max iters
paced control (100/s, 60B) 100 (±0%) 97.9 (-3%) 5 (±0%) 4.9 (-2%) 122 (+16%) 396 (+187%) 503 (+194%) 1133 (+348%) 795 (+557%) 10
size sweep (100/s, 160B-12KB) 100 (±0%) 100 (+1%) 333 (±0%) 334 (+1%) 167 (+38%) 397 (+184%) 953 (+335%) 1202 (+107%) 261 (+93%) 10
replay gateway-gpt-5.4-nano-2000t (1x) 89.2 (±0%) 89.1 (±0%) 16.2 (±0%) 16.2 (±0%) 140 (+5%) 279 (+92%) 424 (+121%) 1180 (+249%) 379 (+30%) 3
replay eve-gpt-5.6-sol-2000t (1x) 54.7 (±0%) 54.7 (±0%) 355 (±0%) 355 (±0%) 181 (+24%) 158 (+14%) 215 (+5%) 392 (+9%) 494 (+52%) 2
replay eve-gpt-5.6-sol-2000t (2x) 109 (±0%) 109 (-1%) 710 (±0%) 710 (-1%) 121 (+12%) 248 (±0%) 345 (-10%) 714 (-18%) 822 (+18%) 3
📈 STSO distribution vs main (inline / queue-hop histograms)

1020 steps (inline)

Cumulative STSO time: main 222159ms → this run 257206ms (Δ +35047ms, +16%)

  100-150 ms  ┃                         main  22  this   2   -20
  150-200 ms  ██┃██████████████         main 386  this  61  -325
  200-250 ms  ████████████████████░░░┃  main 450  this 545   +95
  250-300 ms  █████░░░░░░░┃             main 113  this 288  +175
  300-350 ms  █░░┃                      main  29  this  82   +53
  350-400 ms  ┃                         main   2  this  19   +17
  400-450 ms  ┃                         main   7  this   7    +0
  450-500 ms  ┃                         main   5  this   8    +3
  500-550 ms  ┃                         main   2  this   2    +0
  550-600 ms  ┃                         main   0  this   1    +1
  600-650 ms  ┃                         main   2  this   0    -2
  650-700 ms  ┃                         main   0  this   2    +2
  800-850 ms  ┃                         main   1  this   0    -1
  850-900 ms  ┃                         main   0  this   1    +1
1100-1150 ms  ┃                         main   0  this   1    +1
📈 CRTT drill-down vs main (RTT distributions & profiles) 
variant  RTT 1ms→5s+              avg         p50          p90           p99     n
control  ······▂█▅▁▁··  240.3 (+118%)  160 (+54%)  503 (+194%)  1133 (+348%)  3000
sweep    ······▂█▆▁▁··   240.4 (+89%)  166 (+55%)  953 (+335%)  1202 (+107%)  3000
gw 1x    ·····▁▃█▃▁▁··   177.2 (+57%)  127 (+25%)  424 (+121%)  1180 (+249%)  5295
eve 1x   ·····▁▄█▂▁···   134.2 (+13%)  120 (+19%)    215 (+5%)     392 (+9%)  5186
eve 2x   ·····▁▂█▅▁···    186.6 (±0%)  166 (+11%)   345 (-10%)    714 (-18%)  7779

RTT over stream progress (avg per tenth of stream, bars scaled min→max):

control  ▂▂▁██▇▆▅▅▃  141–330ms
sweep    ▂▁▇▅▆▅▅█▆▄  174–292ms
gw 1x    ▁▁█▁▁▄▇▅▃▃  133–259ms
eve 1x   ▇▁▂▄▁▄█▇▅▂  115–159ms
eve 2x   ▂▁▂▄▃▇▆█▆▃  136–250ms

RTT by chunk size (avg per log size bin, ~160B → ~12KB serialized, bars scaled min→max):

sweep  ▂▁▄▅▇██  237–243ms

Delivery jitter over stream progress (avg positive CDV per tenth of stream, bars scaled min→max):

control  ▂▃▃█▄▂▁▂▄▃  26–105ms
sweep    ▂▄█▂▅▄▅▃▁▂  37–92ms
gw 1x    ▁▂▃▃▁▄█▅▃▁  38–64ms
eve 1x   ▅▁▂▃▄▄█▆▆▅  23–36ms
eve 2x   ▃▃▄█▃▆▃▂▁▆  26–37ms
📜 Previous results (4)

3c3193a

Sat, 15 Aug 2026 06:26:56 GMT · run logs

vercel / nextjs-turbopack

Metric Scenario Best (ms) P75 (ms) P90 (ms) P99 (ms) Samples
TTFS step 379 (+67%) 🔻 1360 🔴 (+19%) 🔻 1372 🔴 (+13%) 1645 🔴 (+21%) 🔻 30
TTFS stream 1275 (+443%) 🔻 1340 🔴 (+12%) 1355 🔴 (+7.0%) 1441 🔴 (+6.7%) 30
TTFS hook + stream 1544 (+271%) 🔻 1622 🔴 (+14%) 1665 🔴 (+14%) 1788 🔴 (+15%) 🔻 30
Fan-out TTFS Promise.all(100 steps) 970 (-27%) 💚 1405 (-45%) 💚 2639 (-2.4%) 2797 (-13%) 10
Fan-out TTLS Promise.all(100 steps) 9920 (-8.7%) 10647 (-90%) 💚 12177 (-93%) 💚 13418 (-93%) 💚 10
STSO 1020 steps (inline) 137 (-11%) 428 (-14%) 461 (-18%) 💚 644 (-18%) 💚 1018
STSO 1020 steps (queue-hop) 3429 3429 3429 3429 1
WO 1020 steps 391327 (-5.6%) 391327 (-5.6%) 391327 (-5.6%) 391327 (-5.6%) 1
CRTT first chunk (pooled) 79 (-19%) 💚 123 (-21%) 💚 199 (-16%) 💚 237 (-18%) 💚 28

Streams

Scenario wr c/s rd c/s wr KiB/s rd KiB/s CRTT 1st p75 p90 p99 CDV max iters
paced control (100/s, 60B) 100 (±0%) 100 (-2%) 5 (±0%) 5 (-2%) 103 (-24%) 117 (-61%) 146 (-86%) 456 (-69%) 128 (-39%) 10
size sweep (100/s, 160B-12KB) 100 (±0%) 100 (+1%) 334 (±0%) 334 (+1%) 97.5 (-16%) 122 (-65%) 154 (-80%) 619 (-51%) 83 (-73%) 10
replay gateway-gpt-5.4-nano-2000t (1x) 89.2 (±0%) 89 (±0%) 16.2 (±0%) 16.2 (-1%) 127 (+27%) 396 (+183%) 2010 (+941%) 3585 (+311%) 415 (+14%) 3
replay eve-gpt-5.6-sol-2000t (1x) 54.7 (±0%) 54.7 (±0%) 355 (±0%) 355 (±0%) 95.5 (-43%) 110 (-38%) 138 (-84%) 486 (-87%) 365 (-81%) 2
replay eve-gpt-5.6-sol-2000t (2x) 109 (±0%) 109 (±0%) 710 (±0%) 708 (±0%) 120 (-5%) 230 (-20%) 370 (-45%) 571 (-71%) 339 (-66%) 3

4c4ae3b

Wed, 12 Aug 2026 00:08:45 GMT · run logs

vercel / nextjs-turbopack

Metric Scenario Best (ms) P75 (ms) P90 (ms) P99 (ms) Samples
TTFS step 282 (-13%) 1341 🔴 (+27%) 🔻 1373 🔴 (+23%) 🔻 1414 🔴 (+1.1%) 30
TTFS stream 1274 (+701%) 🔻 1325 🔴 (+23%) 🔻 1343 🔴 (+23%) 🔻 1410 🔴 (+14%) 30
TTFS hook + stream 1566 (+17%) 🔻 1635 🔴 (+12%) 1670 🔴 (+12%) 1700 🔴 (+8.2%) 30
STSO 1020 steps (inline) 111 (-13%) 161 (-15%) 180 (-17%) 💚 305 (-28%) 💚 1019
WO 1020 steps 165392 (-10%) 165392 (-10%) 165392 (-10%) 165392 (-10%) 1
SL stream latency 77 (-11%) 110 🔴 (-13%) 129 🔴 (-5.8%) 139 🔴 (-71%) 💚 30
SO stream overhead (text) 114 (+5.6%) 156 (-22%) 💚 170 (-46%) 💚 322 (-32%) 💚 30
SO stream overhead (structured) 106 (-0.9%) 162 (-8.5%) 182 (-24%) 💚 255 (-42%) 💚 30

1d1993a

Tue, 11 Aug 2026 23:38:55 GMT · run logs

vercel / nextjs-turbopack

Metric Scenario Best (ms) P75 (ms) P90 (ms) P99 (ms) Samples
TTFS step 1292 (+300%) 🔻 1439 🔴 (+36%) 🔻 1450 🔴 (+29%) 🔻 1500 🔴 (+7.3%) 30
TTFS stream 1346 (+747%) 🔻 1439 🔴 (+34%) 🔻 1446 🔴 (+33%) 🔻 1486 🔴 (+20%) 🔻 30
TTFS hook + stream 1563 (+17%) 🔻 1683 🔴 (+16%) 🔻 1714 🔴 (+15%) 1750 🔴 (+11%) 30
STSO 1020 steps (inline) 117 (-7.9%) 154 (-19%) 💚 171 (-21%) 💚 297 (-30%) 💚 1019
WO 1020 steps 154146 (-16%) 💚 154146 (-16%) 💚 154146 (-16%) 💚 154146 (-16%) 💚 1
SL stream latency 85 (-2.3%) 120 🔴 (-5.5%) 149 🔴 (+8.8%) 212 🔴 (-56%) 💚 30
SO stream overhead (text) 103 (-4.6%) 155 (-23%) 💚 172 (-45%) 💚 197 (-59%) 💚 30
SO stream overhead (structured) 104 (-2.8%) 177 (±0%) 324 (+35%) 🔻 469 (+6.3%) 30

1f3148b

Tue, 11 Aug 2026 20:37:32 GMT · run logs

vercel / nextjs-turbopack

Metric Scenario Best (ms) P75 (ms) P90 (ms) P99 (ms) Samples
TTFS step 281 (-42%) 💚 1377 🔴 (+21%) 🔻 1410 🔴 (+19%) 🔻 1461 🔴 (+17%) 🔻 30
TTFS stream 1288 (+326%) 🔻 1352 🔴 (+21%) 🔻 1382 🔴 (+21%) 🔻 1467 🔴 (+24%) 🔻 30
TTFS hook + stream 1549 (+40%) 🔻 1641 🔴 (+16%) 🔻 1698 🔴 (+16%) 🔻 1751 🔴 (+11%) 30
STSO 1020 steps (inline) 123 (-7.5%) 174 (-9.8%) 198 (-11%) 285 (-15%) 1019
WO 1020 steps 174472 (-6.5%) 174472 (-6.5%) 174472 (-6.5%) 174472 (-6.5%) 1
SL stream latency 85 (-4.5%) 117 🔴 (-14%) 125 🔴 (-42%) 💚 162 🔴 (-54%) 💚 30
SO stream overhead (text) 105 (±0%) 170 (-16%) 💚 219 (-17%) 💚 617 (+65%) 🔻 30
SO stream overhead (structured) 113 (+1.8%) 169 (-11%) 196 (-19%) 💚 217 (-38%) 💚 30
ℹ️ Metric definitions & methodology

Streams: writer/reader sustained rates (steady window, 10% trimmed each side), first-chunk RTT (the stream-open path, before any buffering/backpressure), CRTT percentiles, and worst delivery stall (CDV max). Cells are medians across iterations; per-run values in the artifacts. No 🔴/🟢 marks until targets attach.

The collapsed STSO distribution section above buckets every step gap, split inline (same warm process — pure framework overhead) vs queue-hop (fresh process — dispatch, reinit, replay). █ = main, ┃ = this run, ░ = fill.

The collapsed CRTT drill-down: per-variant RTT histograms (fixed log bins, · = empty) and mean RTT/positive-CDV profile lines over stream progress and chunk size. Histograms, avgs, and profiles merge exactly across runs; p50–p99 are percentile-of-percentiles. Per-index rows live in the artifacts.

Best/P75/P90/P99 deltas compare against the most recent benchmark run on main at the time of this run. 🔻 flags a delta worse than +15%, 💚 one better than −15%.

Metrics — TTFS: time to first step body (in-deployment start() → first step body) · Fan-out TTFS: fan-out time to first step (in-deployment start() → first of the parallel step bodies to complete) · Fan-out TTLS: fan-out time to last step (in-deployment start() → last of the parallel step bodies to complete, i.e. when the Promise.all resolves) · STSO: step-to-step overhead (gap between consecutive step bodies) · WO: workflow overhead (whole-run time outside step bodies, in-deployment anchored) · CRTT: chunk round-trip time (per-chunk write → read latency, one clock domain: deployment → stream backend → same deployment) · CDV: chunk delay variation / delivery jitter (inter-arrival gap minus inter-write gap per seq-adjacent pair; skew-free; the row is each run's MAX positive value, so one stall moves it)

Scenarios — step: one trivial no-op step, no stream; no hooks, so the run stays in turbo mode (in-process fast path) · stream: one streaming step; no hooks, so the run stays in turbo mode (in-process fast path) · hook + stream: registers a hook before one step, which exits turbo mode (dispatch path) · 1020 steps: 1020 trivial sequential steps; STSO is measured between consecutive steps in the given step ranges, and WO is the whole-run overhead outside step bodies · Promise.all(100 steps): 100 trivial no-op steps started together in a single Promise.all; Fan-out TTFS is the first of them to complete and Fan-out TTLS the last, both from the in-deployment clientStart, so their gap is the spread the runtime adds across the fan-out · paced control (100/s, 60B): the control: 300 tiny (~60B) deltas metronome-paced at 100/s — zero workload structure, so it reads the transport floor and flush cadence, and disambiguates transport-wide vs workload-specific when a replay row moves · size sweep (100/s, 160B-12KB): same pacing as the control with deltas padded in rotation across seven log-spaced sizes (~160B–12KB) — rotation decouples size from stream position, so it isolates whether chunk size causes latency · replay gateway-gpt-5.4-nano-2000t (1x): raw provider SSE cadence captured at the AI gateway boundary (gpt-5.4-nano, the most popular gateway model; per-token deltas p50 208B = the modal production chunk size), replayed exactly as measured — the typical customer's workload; its CDV is the typical customer's real delivery jitter · replay eve-gpt-5.6-sol-2000t (1x): a captured eve turn (gpt-5.6-sol, the most-used demanding eve model; ~2000 output tokens = production p50 turn length) replayed exactly as measured — eve's envelope protocol re-ships the cumulative message so sizes ramp 142B→13KB; the demanding outlier tenant's reality · replay eve-gpt-5.6-sol-2000t (2x): the same eve capture at 2x — the headroom/stress row; real fast-tier models emit the same chunk sizes at proportionally higher rate, so time compression is a faithful speed model · first chunk (pooled): every run's seq-0 RTT pooled across all stream scenarios — the first chunk precedes any workload differentiation, so pooling samples one shared stream-open path with exact percentiles

Replay cadences (semantic sha256) — eve-gpt-5.6-sol-2000t eaf22f5946e7c61f3c65c7006d550df180cfabd4e706254a09f22aec0cfb420d · gateway-gpt-5.4-nano-2000t 6f24ac518b6b83ff1d0e85a5fe78230db192716d66a7fc6b2fe022752001d041

🔴 marks a percentile over its target (within target is left unmarked). Targets (p75/p90/p99, ms) — TTFS 200/300/600

All timestamps are deployment-side; runs are triggered in-deployment, so the CI runner and api.vercel.com sit outside every measured window. TTFS = start() → first step body (includes dispatch + any cold start); Fan-out TTFS/TTLS = first/last step completion of one Promise.all from the same anchor (the gap is the runtime’s fan-out spread); STSO/WO between step bodies; CRTT inside the workflow (excludes the api.vercel.com read path).

Cold starts stay in the numbers (real bursty-workload latency, inflates P75+); Best is the warm floor.

This was referenced Aug 11, 2026
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Sim World

Simulated world deterministic testing for races. Traces

🟠 world-sim scenario book — 1 fail of 41 total

fence=per-spec

scenario outcome events virt replay violations
✅ smoke-no-steps completed 3 0ms ok 0
✅ smoke-one-step completed 6 0ms ok 0
✅ hook-at-step-started completed 12 0ms ok 0
✅ hook-at-step-completed completed 12 0ms ok 0
✅ hook-at-hook-created completed 12 0ms ok 0
✅ deadline-hook-wins completed 7 1.0h ok 0
✅ deadline-expires completed 7 1.0h ok 0
✅ long-sleep completed 11 30.0d ok 0
✅ hook-never-arrives stalled 3 0ms skipped 0
✅ step-retries-twice completed 10 2.0s ok 0
✅ parallel-steps completed 9 0ms ok 0
✅ hook-on-execution-state completed 12 0ms ok 0
✅ peek-hook-before-branch completed 12 0ms ok 0
✅ peek-hook-after-branch completed 12 0ms ok 0
✅ peek-hook-at-registration completed 12 0ms ok 0
✅ race-hook-before-probe completed 12 0ms ok 0
✅ race-hook-after-probe completed 12 0ms ok 0
✅ race-duplicate-delivery completed 13 0ms ok 0
✅ attr-hook-before-step completed 11 0ms ok 0
✅ attr-hook-after-step completed 11 0ms ok 0
✅ attr-from-step-body completed 13 0ms ok 0
✅ fork-hook-after-timeout completed 14 1.0m ok 0
✅ fork-hook-before-timeout completed 14 1.0m ok 0
✅ count-hook-after-timeout completed 17 1.0m ok 0
✅ count-hook-before-timeout completed 20 1.0m ok 0
✅ stale-read-step-count-fork completed 20 1.0m ok 0
✅ stale-read-equal-step-counts completed 14 1.0m ok 0
✅ step-vs-step-fork completed 12 0ms ok 0
✅ step-vs-step-fork-fenced completed 12 0ms ok 0
✅ fence-catches-benign-direction completed 12 5ms ok 0
✅ in-flight-before-decision completed 17 1.0m ok 0
❌ in-flight-before-decision-counted completed 17 1.0m ok 0
✅ in-flight-after-decision completed 19 2.0m ok 0
✅ stale-read-step-count-fork-fenced completed 20 1.0m ok 0
✅ fork-hook-wins completed 13 1.0m ok 0
✅ fork-timeout-wins completed 13 1.0m ok 0
✅ unclaimed-payload-under-fork completed 17 1.0m ok 0
✅ claimed-payload-under-fork completed 17 1.0m ok 0
✅ writers-independent-step-bodies completed 12 0ms ok 0
✅ writers-scripted-tempo completed 12 0ms ok 0
✅ cancel-mid-step cancelled 7 0ms skipped 0

Full trace: world-sim.txt

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Comment thread packages/core/e2e/dev.test.ts
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vercel Bot temporarily deployed to Preview – workflow-docs August 11, 2026 23:51 Inactive
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