fix(core): publish a dynamic run only after its code is stored by alangenfeld · Pull Request #4530 · vercel/workflow

alangenfeld · 2026-09-30T19:48:07Z

Summary & Motivation

The queue message for a dynamic run carries the workflow code inline, and turbo can execute the first step from that message before run_started lands — so publishing in parallel with run_created let a run execute even when the backend refused or dropped the code, and start() reported a failure the caller couldn't act on. Dynamic starts now await run_created and confirm the stored code before queueing; any create failure, retryable or not, reaches the caller with nothing published, since there is no resilient start for a dynamic run. Static starts keep the parallel path. The extra sequential round trip only applies to dynamic starts, which are rare and already pay for compilation and sometimes an upload.

Test Plan

Unit tests cover the dynamic publish gate; manual repro against a Local World that strips the stored code confirmed both runs stayed pending with no steps and never received a flow delivery, and that the normal Local World still completes hello, upload-path, fan-out, and hook-resume dynamic runs.

Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

vercel · 2026-09-30T19:48:16Z

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

Project	Deployment	Actions	Updated
example-nextjs-workflow-turbopack	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
example-nextjs-workflow-webpack	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
example-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-astro-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-express-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-fastify-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-hono-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-nestjs-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-nitro-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-nuxt-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-python-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-sveltekit-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-tanstack-start-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workbench-vite-workflow	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workflow-docs	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workflow-swc-playground	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workflow-tarballs	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC
workflow-web	Ready	Preview, v0	Sep 30, 2026 9:06pm UTC

changeset-bot · 2026-09-30T19:48:25Z

🦋 Changeset detected

Latest commit: cb94954

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 17 packages

Name	Type
@workflow/core	Patch
@workflow/builders	Patch
@workflow/cli	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	Patch
@workflow/web-shared	Patch
@workflow/web	Patch
workflow	Patch
@workflow/world-testing	Patch
@workflow/astro	Patch
@workflow/nest	Patch
@workflow/rollup	Patch
@workflow/sveltekit	Patch
@workflow/vite	Patch
@workflow/nuxt	Patch
@workflow/world-vercel	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

github-actions · 2026-09-30T19:49:09Z

📊 Workflow Benchmarks

commit 9b7485e · Wed, 30 Sep 2026 21:22:52 GMT · run logs

Backend: vercel · app: nextjs-turbopack

Metric	Scenario	Best (ms)	P75 (ms)	P90 (ms)	P99 (ms)	Samples
TTFS	step	550 (-25%) 💚	2464 🔴 (+126%) 🔻	2507 🔴 (+125%) 🔻	2619 🔴 (+118%) 🔻	30
TTFS	stream	2355 (+970%) 🔻	2489 🔴 (+137%) 🔻	2572 🔴 (+134%) 🔻	2805 🔴 (+97%) 🔻	30
TTFS	hook + stream	759 (-13%)	2797 🔴 (+111%) 🔻	2878 🔴 (+105%) 🔻	3136 🔴 (+101%) 🔻	30
Fan-out TTFS	Promise.all(100 steps)	531 (-39%) 💚	762 (-55%) 💚	821 (-54%) 💚	2749 (+47%) 🔻	10
Fan-out TTLS	Promise.all(100 steps)	2417 (+5.4%)	3578 (-1.4%)	5440 (+44%) 🔻	10549 (+46%) 🔻	10
STSO	1020 steps (inline)	86 (-14%)	178 (+37%) 🔻	198 (+29%) 🔻	296 (+46%) 🔻	1019
WO	1020 steps	174690 (+33%) 🔻	174690 (+33%) 🔻	174690 (+33%) 🔻	174690 (+33%) 🔻	1
CRTT	first chunk (pooled)	62 (-14%)	85 (-40%) 💚	98 (-54%) 💚	113 (-68%) 💚	28

Streams

Scenario	CRTT 1st	p75	p90	p99	CDV max	iters
paced control (100/s, 60B)	77.5 (-21%)	131 (-32%)	176 (-42%)	724 (+47%)	116 (-48%)	10
size sweep (100/s, 160B-12KB)	72.5 (-30%)	133 (-41%)	168 (-52%)	270 (-57%)	110 (-48%)	10
replay gateway-gpt-5.4-nano-2000t (1x)	83 (-39%)	127 (-33%)	153 (-52%)	304 (-47%)	130 (-70%)	3
replay eve-gpt-5.6-sol-2000t (1x)	89.5 (-14%)	127 (-36%)	155 (-49%)	364 (-34%)	219 (-52%)	2
replay eve-gpt-5.6-sol-2000t (2x)	85 (-40%)	149 (-54%)	189 (-61%)	335 (-64%)	181 (-61%)	3

📈 STSO distribution vs main (inline / queue-hop histograms)

1020 steps (inline)

Cumulative STSO time: main 131526ms → this run 174064ms (Δ +42538ms, +32%)

 50-100 ms  ┃                         main   0  this   1    +1
100-150 ms  ███┃████████████████████  main 899  this 140  -759
150-200 ms  ███░░░░░░░░░░░░░░░░░┃     main 108  this 779  +671
200-250 ms  █┃                        main   8  this  70   +62
250-300 ms  ┃                         main   2  this  19   +17
300-350 ms  ┃                         main   0  this   4    +4
350-400 ms  ┃                         main   1  this   3    +2
400-450 ms  ┃                         main   1  this   2    +1
450-500 ms  ┃                         main   0  this   1    +1

📈 CRTT drill-down vs main (RTT distributions & profiles)

variant  RTT 1ms→5s+             avg         p50         p90         p99     n
control  ······▆█▁▁···  117.6 (-26%)  107 (-22%)  176 (-42%)  724 (+47%)  3000
sweep    ······▅█▁····  112.2 (-36%)  109 (-30%)  168 (-52%)  270 (-57%)  3000
gw 1x    ·····▁▇█▁····  107.1 (-33%)  103 (-24%)  153 (-52%)  304 (-47%)  5295
eve 1x   ·····▁██▁▁···    111 (-32%)  100 (-26%)  155 (-49%)  364 (-34%)  5186
eve 2x   ·····▁▅█▁····  122.1 (-47%)  116 (-46%)  189 (-61%)  335 (-64%)  7779

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

control  ▂██▃▃▃▂▁▁▁  102–153ms
sweep    █▄▆▇▁▇▆▂▇▅  102–119ms
gw 1x    ▃▁▃█▃▁▃▇▃▁  102–117ms
eve 1x   ▂▂▂▂▁▃█▆▇▂  98–133ms
eve 2x   ▂▁▅▅▃▃██▆▄  108–136ms

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

sweep  ▃▅▅█▆▂▁  110–114ms

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

control  ▂█▇▂▅▅▅▁▃▄  27–39ms
sweep    ▄▂▆▂▃▅▃▃█▁  43–56ms
gw 1x    ▃▂▂▂▃▄▇█▃▁  29–37ms
eve 1x   ▄▄▃▁▃▅█▅▄█  18–26ms
eve 2x   ▆▆▂▅▆▄▄▁▁█  17–24ms

📜 Previous results (1)

`cb94954`

Wed, 30 Sep 2026 20:11:37 GMT · run logs

vercel / nextjs-turbopack

Metric	Scenario	Best (ms)	P75 (ms)	P90 (ms)	P99 (ms)	Samples
TTFS	step	2286 (+338%) 🔻	2716 🔴 (+35%) 🔻	2804 🔴 (+38%) 🔻	3137 🔴 (+9.3%)	30
TTFS	stream	2302 (+26%) 🔻	2765 🔴 (+42%) 🔻	2797 🔴 (+43%) 🔻	2895 🔴 (+34%) 🔻	30
TTFS	hook + stream	796 (-57%) 💚	3029 🔴 (+33%) 🔻	3148 🔴 (+36%) 🔻	3224 🔴 (+36%) 🔻	30
Fan-out TTFS	Promise.all(100 steps)	641 (+11%)	2749 (+235%) 🔻	2895 (+232%) 🔻	3622 (+62%) 🔻	10
Fan-out TTLS	Promise.all(100 steps)	2271 (+16%) 🔻	7938 (+176%) 🔻	8949 (+83%) 🔻	11462 (+83%) 🔻	10
STSO	1020 steps (inline)	142 (-0.7%)	204 (+3.6%)	232 (+2.2%)	408 (+13%)	1019
WO	1020 steps	200606 (+3.3%)	200606 (+3.3%)	200606 (+3.3%)	200606 (+3.3%)	1
CRTT	first chunk (pooled)	64 (-7.2%)	103 (-3.7%)	156 (-5.5%)	4200 (+827%) 🔻	28

Streams

Scenario	CRTT 1st	p75	p90	p99	CDV max	iters
paced control (100/s, 60B)	89.5 (+10%)	183 (+41%)	458 (+134%)	4174 (+903%)	158 (+68%)	10
size sweep (100/s, 160B-12KB)	91 (+6%)	172 (+28%)	318 (+92%)	653 (+132%)	147 (+14%)	10
replay gateway-gpt-5.4-nano-2000t (1x)	74 (-6%)	124 (-80%)	144 (-83%)	469 (-61%)	163 (-61%)	3
replay eve-gpt-5.6-sol-2000t (1x)	139 (+67%)	623 (+355%)	2373 (+1169%)	5132 (+626%)	2308 (+255%)	2
replay eve-gpt-5.6-sol-2000t (2x)	72 (-44%)	163 (+4%)	216 (+10%)	1401 (+317%)	323 (+44%)	3

ℹ️ Metric definitions & methodology

_{Streams: 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.}

github-actions · 2026-09-30T19:49:13Z

🧪 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.

health check (CLI) - workflow health command reports healthy endpoints (nextjs-webpack · local-dev / local / node / stable)
hookWithSleepWorkflow - hook payloads delivered correctly with concurrent sleep (nextjs-webpack · local-dev / local / node / stable)

🛠 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 · runs app-generated source against a registered step (tanstack-start) · at 21:07:15Z · abandoned wrun_01M3T28RT8FXHZMBSCQRQQF0JF
cold-start-warmup · suite warmup (tanstack-start) · at 21:07:23Z · abandoned wrun_01M3T28RTCKQGY663KMQ8HPCFA
run-pickup-stall · instanceMethodStepWorkflow - instance methods with "use step" directive (nuxt) · at 21:09:52Z · abandoned wrun_01M3T2DJ9GEFKHXVSQYC3W476Y
run-pickup-stall · hookCleanupTestWorkflow - hook token reuse after workflow completion (nextjs-webpack) · at 21:12:19Z · abandoned wrun_01M3T2J1F1TZ9JRTVPA0SD4T22
run-pickup-stall · ChainableService.processWithThis - static step methods using this to reference the class (nextjs-webpack) · at 21:13:41Z · abandoned wrun_01M3T2MJ0YGGV9T3V28WHA6QPQ
run-pickup-stall · thisSerializationWorkflow - step function invoked with .call() and .apply() (nextjs-webpack) · at 21:13:50Z · abandoned wrun_01M3T2MT5DCC85349HJ1ATKKXN
run-pickup-stall · customSerializationWorkflow - custom class serialization with WORKFLOW_SERIALIZE/WORKFLOW_DESERIALIZE (nextjs-webpack) · at 21:13:50Z · abandoned wrun_01M3T2MT9X03AE62N5JDCRSMMD
run-pickup-stall · hookWithSleepWorkflow - hook payloads delivered correctly with concurrent sleep (nextjs-webpack) · at 21:14:34Z · abandoned wrun_01M3T2P5EE657SFF0B2WWBT6FR

E2E Test Summary

Summary

	Passed	Skipped	Total
✅ ▲ Vercel Production	3904	875	4779
✅ 💻 Local Development	4406	550	4956
✅ 📦 Local Production	4406	550	4956
✅ 🐘 Local Postgres	4406	550	4956
✅ 🪟 Windows	342	12	354
✅ 🌐 Cross-language Conformance	68	84	152
✅ dynamic-runs	0	0	0
✅ vercel-http-transport	879	183	1062
✅ vercel-multi-region	27	0	27
✅ vercel-ws-transport	595	113	708
Total	19033	2917	21950

Details by Category

✅ ▲ Vercel Production

App	Passed	Skipped
✅ astro-node	142	35
✅ astro-quickjs	142	35
✅ example-node	142	35
✅ example-quickjs	142	35
✅ express-node	142	35
✅ express-quickjs	142	35
✅ fastify-node	142	35
✅ fastify-quickjs	142	35
✅ hono-node	142	35
✅ hono-quickjs	142	35
✅ nest-node	142	35
✅ nest-quickjs	142	35
✅ nextjs-turbopack-node	169	8
✅ nextjs-turbopack-quickjs	169	8
✅ nextjs-webpack-node	169	8
✅ nextjs-webpack-quickjs	169	8
✅ nitro-node	142	35
✅ nitro-quickjs	142	35
✅ nuxt-node	142	35
✅ nuxt-quickjs	142	35
✅ python-node	66	111
✅ sveltekit-node	161	16
✅ sveltekit-quickjs	161	16
✅ tanstack-start-node	142	35
✅ tanstack-start-quickjs	142	35
✅ vite-node	142	35
✅ vite-quickjs	142	35

✅ 💻 Local Development

App	Passed	Skipped
✅ astro-stable-node	148	29
✅ astro-stable-quickjs	148	29
✅ express-stable-node	148	29
✅ express-stable-quickjs	148	29
✅ fastify-stable-node	148	29
✅ fastify-stable-quickjs	148	29
✅ hono-stable-node	148	29
✅ hono-stable-quickjs	148	29
✅ nest-stable-node	148	29
✅ nest-stable-quickjs	148	29
✅ nextjs-turbopack-canary-node	176	1
✅ nextjs-turbopack-canary-quickjs	176	1
✅ nextjs-turbopack-stable-node	176	1
✅ nextjs-turbopack-stable-quickjs	176	1
✅ nextjs-webpack-canary-node	176	1
✅ nextjs-webpack-canary-quickjs	176	1
✅ nextjs-webpack-stable-node	176	1
✅ nextjs-webpack-stable-quickjs	176	1
✅ nitro-stable-node	148	29
✅ nitro-stable-quickjs	148	29
✅ nuxt-stable-node	148	29
✅ nuxt-stable-quickjs	148	29
✅ sveltekit-stable-node	167	10
✅ sveltekit-stable-quickjs	167	10
✅ tanstack-start-node	148	29
✅ tanstack-start-quickjs	148	29
✅ vite-stable-node	148	29
✅ vite-stable-quickjs	148	29

✅ 📦 Local Production

App	Passed	Skipped
✅ astro-stable-node	148	29
✅ astro-stable-quickjs	148	29
✅ express-stable-node	148	29
✅ express-stable-quickjs	148	29
✅ fastify-stable-node	148	29
✅ fastify-stable-quickjs	148	29
✅ hono-stable-node	148	29
✅ hono-stable-quickjs	148	29
✅ nest-stable-node	148	29
✅ nest-stable-quickjs	148	29
✅ nextjs-turbopack-canary-node	176	1
✅ nextjs-turbopack-canary-quickjs	176	1
✅ nextjs-turbopack-stable-node	176	1
✅ nextjs-turbopack-stable-quickjs	176	1
✅ nextjs-webpack-canary-node	176	1
✅ nextjs-webpack-canary-quickjs	176	1
✅ nextjs-webpack-stable-node	176	1
✅ nextjs-webpack-stable-quickjs	176	1
✅ nitro-stable-node	148	29
✅ nitro-stable-quickjs	148	29
✅ nuxt-stable-node	148	29
✅ nuxt-stable-quickjs	148	29
✅ sveltekit-stable-node	167	10
✅ sveltekit-stable-quickjs	167	10
✅ tanstack-start-node	148	29
✅ tanstack-start-quickjs	148	29
✅ vite-stable-node	148	29
✅ vite-stable-quickjs	148	29

✅ 🐘 Local Postgres

App	Passed	Skipped
✅ astro-stable-node	148	29
✅ astro-stable-quickjs	148	29
✅ express-stable-node	148	29
✅ express-stable-quickjs	148	29
✅ fastify-stable-node	148	29
✅ fastify-stable-quickjs	148	29
✅ hono-stable-node	148	29
✅ hono-stable-quickjs	148	29
✅ nest-stable-node	148	29
✅ nest-stable-quickjs	148	29
✅ nextjs-turbopack-canary-node	176	1
✅ nextjs-turbopack-canary-quickjs	176	1
✅ nextjs-turbopack-stable-node	176	1
✅ nextjs-turbopack-stable-quickjs	176	1
✅ nextjs-webpack-canary-node	176	1
✅ nextjs-webpack-canary-quickjs	176	1
✅ nextjs-webpack-stable-node	176	1
✅ nextjs-webpack-stable-quickjs	176	1
✅ nitro-stable-node	148	29
✅ nitro-stable-quickjs	148	29
✅ nuxt-stable-node	148	29
✅ nuxt-stable-quickjs	148	29
✅ sveltekit-stable-node	167	10
✅ sveltekit-stable-quickjs	167	10
✅ tanstack-start-node	148	29
✅ tanstack-start-quickjs	148	29
✅ vite-stable-node	148	29
✅ vite-stable-quickjs	148	29

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack-node	171	0	6
✅ nextjs-turbopack-quickjs	171	0	6

✅ 🌐 Cross-language Conformance

App	Passed	Failed	Skipped
✅ python	68	0	84

✅ dynamic-runs

App	Passed	Failed	Skipped
✅ astro-vercel	0	0	0
✅ example-vercel	0	0	0
✅ express-vercel	0	0	0
✅ fastify-vercel	0	0	0
✅ hono-vercel	0	0	0
✅ nest-vercel	0	0	0
✅ nextjs-turbopack-vercel	0	0	0
✅ nextjs-webpack-vercel	0	0	0
✅ nitro-vercel	0	0	0
✅ nuxt-vercel	0	0	0
✅ sveltekit-vercel	0	0	0
✅ tanstack-start-vercel	0	0	0
✅ vite-vercel	0	0	0

✅ vercel-http-transport

App	Passed	Skipped
✅ example	142	35
✅ express	142	35
✅ hono	142	35
✅ nextjs-turbopack	169	8
✅ nitro	142	35
✅ vite	142	35

✅ vercel-multi-region

App	Passed	Failed	Skipped
✅ nextjs-turbopack	27	0	0

✅ vercel-ws-transport

App	Passed	Skipped
✅ example	142	35
✅ express	142	35
✅ nextjs-turbopack	169	8
✅ vite	142	35

📋 View full workflow run

github-actions · 2026-09-30T19:52:28Z

Sim World

Simulated world deterministic testing for races. Traces

🟠 world-sim scenario book — 1 fail of 42 total

fence=per-spec

scenario	outcome	events	virt	replay
✅ `smoke-no-steps`	completed	3	0ms	ok
✅ `smoke-one-step`	completed	6	0ms	ok
✅ `hook-at-step-started`	completed	12	0ms	ok
✅ `hook-at-step-completed`	completed	12	0ms	ok
✅ `hook-at-hook-created`	completed	12	0ms	ok
✅ `deadline-hook-wins`	completed	7	1.0h	ok
✅ `deadline-expires`	completed	7	1.0h	ok
✅ `step-vs-timer-early-settlement`	completed	8	1.0h	ok
✅ `long-sleep`	completed	11	30.0d	ok
✅ `hook-never-arrives`	stalled	3	0ms	skipped
✅ `step-retries-twice`	completed	10	2.0s	ok
✅ `parallel-steps`	completed	9	0ms	ok
✅ `hook-on-execution-state`	completed	12	0ms	ok
✅ `peek-hook-before-branch`	completed	12	0ms	ok
✅ `peek-hook-after-branch`	completed	12	0ms	ok
✅ `peek-hook-at-registration`	completed	12	0ms	ok
✅ `race-hook-before-probe`	completed	12	0ms	ok
✅ `race-hook-after-probe`	completed	12	0ms	ok
✅ `race-duplicate-delivery`	completed	13	0ms	ok
✅ `attr-hook-before-step`	completed	11	0ms	ok
✅ `attr-hook-after-step`	completed	11	0ms	ok
✅ `attr-from-step-body`	completed	13	0ms	ok
✅ `fork-hook-after-timeout`	completed	14	1.0m	ok
✅ `fork-hook-before-timeout`	completed	14	1.0m	ok
✅ `count-hook-after-timeout`	completed	17	1.0m	ok
✅ `count-hook-before-timeout`	completed	20	1.0m	ok
✅ `stale-read-step-count-fork`	completed	20	1.0m	ok
✅ `stale-read-equal-step-counts`	completed	14	1.0m	ok
✅ `step-vs-step-fork`	completed	12	0ms	ok
✅ `step-vs-step-fork-fenced`	completed	12	0ms	ok
✅ `fence-catches-benign-direction`	completed	12	5ms	ok
✅ `in-flight-before-decision`	completed	17	1.0m	ok
❌ `in-flight-before-decision-counted`	completed	17	1.0m	ok
✅ `in-flight-after-decision`	completed	19	2.0m	ok
✅ `stale-read-step-count-fork-fenced`	completed	20	1.0m	ok
✅ `fork-hook-wins`	completed	13	1.0m	ok
✅ `fork-timeout-wins`	completed	13	1.0m	ok
✅ `unclaimed-payload-under-fork`	completed	17	1.0m	ok
✅ `claimed-payload-under-fork`	completed	17	1.0m	ok
✅ `writers-independent-step-bodies`	completed	12	0ms	ok
✅ `writers-scripted-tempo`	completed	12	0ms	ok
✅ `cancel-mid-step`	cancelled	7	0ms	skipped

Full trace: world-sim.txt

github-actions · 2026-09-30T19:56:08Z

Framework	Flow route	Step reg.	Framework output
hono	265.9 KiB (+64.3 KiB) ⚠️	97.2 KiB (+56.4 KiB) ⚠️	1.98 MiB (+215.4 KiB)
nextjs-turbopack	273.3 KiB (+66.3 KiB) ⚠️	426 B (-13 B)	979.1 KiB (+210.4 KiB)

About these numbers

Sizes are gzip; parentheses show the change against main.
Flow route and Step reg. gate this job, on raw bytes rather than the gzip shown, at max(2%, 50.0 KiB). Framework output is informational.
⚠️ marks growth past the threshold. Add the allow-bundle-size-growth label to accept it.

9b7485e · run

…ucturing start() Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

github-actions · 2026-09-30T21:23:20Z

No backport to stable for 1fcf4bb (AI decision).

This fixes the publish ordering for dynamic workflow starts (experimental_dynamic), but that functionality does not exist on stable: git show origin/stable:packages/core/src/runtime/start.ts contains no dynamic references at all, and packages/core/e2e/e2e-dynamic-workflow.test.ts is absent from stable. With no dynamic-start path on the maintenance line, there is no defect there to fix.

To override, re-run the Backport to stable workflow manually via workflow_dispatch and paste this commit SHA into the ref input:

1fcf4bb33964e491ebefefbcd0644fe46e8dd1f4

fix(core): publish a dynamic run only after its code is stored

cb94954

Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

vercel Bot deployed to Preview – workflow-docs September 30, 2026 19:50 View deployment

alangenfeld marked this pull request as ready for review September 30, 2026 20:30

alangenfeld requested a review from a team as a code owner September 30, 2026 20:30

VaguelySerious approved these changes Sep 30, 2026

View reviewed changes

refactor(core): gate the dynamic publish on run_created without restr…

9b7485e

…ucturing start() Signed-off-by: Alex Langenfeld <alex.langenfeld@vercel.com>

vercel Bot deployed to Preview – workflow-docs September 30, 2026 21:05 View deployment

alangenfeld merged commit 1fcf4bb into main Sep 30, 2026
182 of 184 checks passed

alangenfeld deleted the alangenfeld/workflow-dynamic-start-fixes branch September 30, 2026 21:22

This was referenced Sep 30, 2026

Version Packages #4526

Merged

Version Packages Thegreatsura/workflow#1

Open

pranaygp mentioned this pull request Oct 1, 2026

[docs] Note fatal dynamic start() refusals and publish-after-store #4558

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fix(core): publish a dynamic run only after its code is stored - #4530

fix(core): publish a dynamic run only after its code is stored#4530
alangenfeld merged 2 commits into
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alangenfeld/workflow-dynamic-start-fixes

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Summary & Motivation

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📊 Workflow Benchmarks

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🧪 E2E Test Results

⚠️ Flaky E2E Tests (passed on retry)

🛠 Infra Events (absorbed by the harness)

E2E Test Summary

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Sim World

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