Decode UTF-8 stream chunks

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
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workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
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[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

---

📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.

[karthikscale3]

What changed

• Added shared formatArrayBufferViewForDisplay + summarizeArrayBufferView helpers in @workflow/web-shared (src/lib/stream-display.ts). They UTF-8 decode typed-array values via TextDecoder({ fatal: true }) and fall back to a compact Uint8Array(N) [..] summary for binary data.
• DataInspector (src/components/ui/data-inspector.tsx) now collapses any ArrayBufferView (other than DataView) into a non-expandable BytesDisplay opaque ref via collapseRefs, then renders it with a DecodedBytesChunk that shows decoded text by default and a Decoded / Bytes toggle to inspect the summarized raw value. Decoded text that parses as JSON is re-rendered through a nested DataInspector.
• stream-viewer.tsx no longer formats stream chunks itself — chunks flow as raw hydrated values straight into DataInspector, so Events tab payloads, Trace detail fields, and stream chunks all share the same typed-array rendering path.
• packages/web/app/lib/hooks/use-stream-reader.ts is dramatically simplified (95 lines removed): it no longer pre-formats chunks, it just keeps them hydrated for the inspector.
• Decoded / Bytes toggle uses aria-pressed + aria-label toggle-button semantics (not role="tab", since the panel content lives above the buttons rather than as a sibling).
• Public API in src/index.ts exposes only the DecodedStreamChunkSource type from this module; the rendering helpers are intentionally internal.
• New regression tests in test/collapse-refs.test.ts (9 cases): top-level typed array, nested in plain object, array, Map values, Set entries, non-Uint8Array views (Int16Array), DataView exclusion, binary fallback summary, and primitive passthrough.

Why

AI agent workflow stream deltas (e.g. helloAgentWorkflow) arrive as Uint8Array values serialized through devalue. The previous viewer collapsed them into compact byte summaries like Uint8Array(87) [65, 73, ...], which made the actual text content unreadable. Decoded text alone would be lossy for binary payloads. Routing everything through DataInspector → collapseRefs keeps the readable default, makes the byte-like source explicit and inspectable, and gives Events / Trace / stream views consistent behavior.

Validation

• pnpm --filter @workflow/web-shared test → 22 passed (22)
• pnpm --filter @workflow/web-shared typecheck → clean
• pnpm --filter @workflow/web-shared build → clean
• pnpm exec biome check on touched files → only pre-existing complexity warnings on untouched code

Reference

• Mirrors https://github.com/vercel/front/pull/68191

[vercel]

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

Project	Deployment	Actions	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-nextjs-workflow-webpack	Ready	Preview, Comment	Apr 28, 2026 11:30pm
example-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-astro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-express-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-fastify-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-hono-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nitro-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-nuxt-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-sveltekit-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workbench-vite-workflow	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-docs	Ready	Preview, Comment, Open in v0	Apr 28, 2026 11:30pm
workflow-swc-playground	Ready	Preview, Comment	Apr 28, 2026 11:30pm
workflow-web	Ready	Preview, Comment	Apr 28, 2026 11:30pm

[changeset-bot]

🦋 Changeset detected

Latest commit: addd614

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

This PR includes changesets to release 17 packages

Name	Type
@workflow/web-shared	Patch
@workflow/web	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/builders	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/vitest	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/ai	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]

🧪 E2E Test Results

✅ All tests passed

Summary

	Passed	Failed	Skipped	Total
✅ ▲ Vercel Production	989	0	67	1056
✅ 💻 Local Development	1066	0	86	1152
✅ 📦 Local Production	1066	0	86	1152
✅ 🐘 Local Postgres	1066	0	86	1152
✅ 🪟 Windows	96	0	0	96
✅ 📋 Other	270	0	18	288
Total	4553	0	343	4896

Details by Category

✅ ▲ Vercel Production

App	Passed	Failed	Skipped
✅ astro	89	0	7
✅ example	89	0	7
✅ express	89	0	7
✅ fastify	89	0	7
✅ hono	89	0	7
✅ nextjs-turbopack	94	0	2
✅ nextjs-webpack	94	0	2
✅ nitro	89	0	7
✅ nuxt	89	0	7
✅ sveltekit	89	0	7
✅ vite	89	0	7

✅ 💻 Local Development

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 📦 Local Production

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🐘 Local Postgres

App	Passed	Failed	Skipped
✅ astro-stable	90	0	6
✅ express-stable	90	0	6
✅ fastify-stable	90	0	6
✅ hono-stable	90	0	6
✅ nextjs-turbopack-canary	77	0	19
✅ nextjs-turbopack-stable	96	0	0
✅ nextjs-webpack-canary	77	0	19
✅ nextjs-webpack-stable	96	0	0
✅ nitro-stable	90	0	6
✅ nuxt-stable	90	0	6
✅ sveltekit-stable	90	0	6
✅ vite-stable	90	0	6

✅ 🪟 Windows

App	Passed	Failed	Skipped
✅ nextjs-turbopack	96	0	0

✅ 📋 Other

App	Passed	Failed	Skipped
✅ e2e-local-dev-nest-stable	90	0	6
✅ e2e-local-postgres-nest-stable	90	0	6
✅ e2e-local-prod-nest-stable	90	0	6

---

📋 View full workflow run

[github-actions]

📊 Benchmark Results

📈 Comparing against baseline from main branch. Green 🟢 = faster, Red 🔺 = slower.

workflow with no steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Nitro	0.041s (-3.9%)	1.005s (~)	0.964s	10	1.00x
💻 Local	Express	0.044s (-1.1%)	1.005s (~)	0.961s	10	1.06x
💻 Local	Next.js (Turbopack)	0.048s	1.005s	0.957s	10	1.16x
🐘 Postgres	Express	0.054s (-6.0% 🟢)	1.011s (~)	0.956s	10	1.32x
🐘 Postgres	Nitro	0.055s (-42.4% 🟢)	1.010s (-3.2%)	0.955s	10	1.32x
🐘 Postgres	Next.js (Turbopack)	0.057s	1.011s	0.953s	10	1.38x

workflow with 1 step

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	1.116s	2.006s	0.890s	10	1.00x
💻 Local	Nitro	1.129s (~)	2.006s (~)	0.877s	10	1.01x
💻 Local	Express	1.130s (~)	2.006s (~)	0.877s	10	1.01x
🐘 Postgres	Next.js (Turbopack)	1.141s	2.010s	0.869s	10	1.02x
🐘 Postgres	Nitro	1.143s (~)	2.009s (~)	0.867s	10	1.02x
🐘 Postgres	Express	1.148s (~)	2.011s (~)	0.862s	10	1.03x

workflow with 10 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	10.794s	11.025s	0.231s	3	1.00x
💻 Local	Nitro	10.946s (~)	11.023s (~)	0.078s	3	1.01x
💻 Local	Express	10.952s (~)	11.024s (~)	0.071s	3	1.01x
🐘 Postgres	Nitro	10.957s (+0.8%)	11.350s (+2.9%)	0.393s	3	1.02x
🐘 Postgres	Express	10.961s (~)	11.028s (~)	0.067s	3	1.02x
🐘 Postgres	Next.js (Turbopack)	11.002s	11.359s	0.357s	3	1.02x

workflow with 25 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	14.507s (-0.6%)	15.023s (~)	0.517s	4	1.00x
🐘 Postgres	Next.js (Turbopack)	14.508s	15.023s	0.514s	4	1.00x
💻 Local	Next.js (Turbopack)	14.596s	15.029s	0.434s	4	1.01x
🐘 Postgres	Express	14.621s (~)	15.027s (~)	0.406s	4	1.01x
💻 Local	Nitro	14.983s (-0.5%)	15.030s (-6.2% 🟢)	0.047s	4	1.03x
💻 Local	Express	14.999s (~)	15.279s (+1.7%)	0.280s	4	1.03x

workflow with 50 sequential steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	13.770s	14.020s	0.251s	7	1.00x
🐘 Postgres	Nitro	13.792s (-1.3%)	14.021s (-2.0%)	0.229s	7	1.00x
🐘 Postgres	Express	14.142s (+1.0%)	14.880s (+2.0%)	0.739s	7	1.03x
💻 Local	Next.js (Turbopack)	15.743s	16.031s	0.288s	6	1.14x
💻 Local	Express	16.535s (~)	17.031s (~)	0.496s	6	1.20x
💻 Local	Nitro	16.756s (~)	17.031s (~)	0.275s	6	1.22x

Promise.all with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.225s	2.010s	0.785s	15	1.00x
🐘 Postgres	Express	1.255s (~)	2.009s (~)	0.754s	15	1.02x
🐘 Postgres	Nitro	1.278s (~)	2.009s (~)	0.731s	15	1.04x
💻 Local	Express	1.513s (+1.6%)	2.005s (~)	0.493s	15	1.24x
💻 Local	Next.js (Turbopack)	1.541s	2.006s	0.465s	15	1.26x
💻 Local	Nitro	1.545s (-5.3% 🟢)	2.006s (-3.3%)	0.460s	15	1.26x

Promise.all with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.325s (-1.1%)	3.009s (~)	0.684s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	2.355s	3.007s	0.653s	10	1.01x
🐘 Postgres	Express	2.365s (~)	3.010s (~)	0.645s	10	1.02x
💻 Local	Next.js (Turbopack)	2.878s	3.342s	0.464s	9	1.24x
💻 Local	Express	2.970s (+0.6%)	3.342s (-3.2%)	0.372s	9	1.28x
💻 Local	Nitro	3.135s (~)	3.761s (-3.2%)	0.626s	8	1.35x

Promise.all with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.466s (~)	4.013s (~)	0.547s	8	1.00x
🐘 Postgres	Express	3.511s (+0.7%)	4.014s (~)	0.503s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.622s	4.014s	0.392s	8	1.05x
💻 Local	Next.js (Turbopack)	7.191s	7.765s	0.575s	4	2.07x
💻 Local	Express	7.682s (-7.9% 🟢)	8.023s (-11.1% 🟢)	0.341s	4	2.22x
💻 Local	Nitro	8.748s (+4.8%)	9.270s (+2.8%)	0.523s	4	2.52x

Promise.race with 10 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	1.233s	2.008s	0.775s	15	1.00x
🐘 Postgres	Nitro	1.262s (~)	2.008s (~)	0.746s	15	1.02x
🐘 Postgres	Express	1.269s (+0.9%)	2.009s (~)	0.740s	15	1.03x
💻 Local	Next.js (Turbopack)	1.522s	2.006s	0.484s	15	1.23x
💻 Local	Nitro	1.541s (-17.4% 🟢)	2.006s (-14.3% 🟢)	0.465s	15	1.25x
💻 Local	Express	1.545s (-18.4% 🟢)	2.006s (-15.1% 🟢)	0.461s	15	1.25x

Promise.race with 25 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	2.318s (-0.9%)	3.009s (~)	0.691s	10	1.00x
🐘 Postgres	Express	2.354s (+0.5%)	3.010s (~)	0.656s	10	1.02x
🐘 Postgres	Next.js (Turbopack)	2.432s	3.009s	0.577s	10	1.05x
💻 Local	Next.js (Turbopack)	2.815s	3.310s	0.495s	10	1.21x
💻 Local	Express	2.839s (-9.4% 🟢)	3.108s (-17.4% 🟢)	0.269s	10	1.22x
💻 Local	Nitro	3.042s (-0.8%)	3.885s (~)	0.843s	8	1.31x

Promise.race with 50 concurrent steps

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	3.475s (~)	4.011s (~)	0.536s	8	1.00x
🐘 Postgres	Express	3.493s (~)	4.011s (~)	0.517s	8	1.01x
🐘 Postgres	Next.js (Turbopack)	3.616s	4.011s	0.395s	8	1.04x
💻 Local	Next.js (Turbopack)	7.662s	8.270s	0.607s	4	2.21x
💻 Local	Express	7.892s (-10.3% 🟢)	8.270s (-10.8% 🟢)	0.378s	4	2.27x
💻 Local	Nitro	8.903s (-2.6%)	9.275s (-7.5% 🟢)	0.372s	4	2.56x

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.778s	1.024s	0.246s	59	1.00x
🐘 Postgres	Nitro	0.806s (-1.8%)	1.006s (~)	0.200s	60	1.04x
🐘 Postgres	Express	0.837s (~)	1.023s (~)	0.186s	59	1.08x
💻 Local	Next.js (Turbopack)	0.865s	1.039s	0.174s	58	1.11x
💻 Local	Nitro	1.000s (+2.0%)	1.309s (+19.7% 🔺)	0.309s	46	1.29x
💻 Local	Express	1.015s (+3.1%)	1.672s (+55.4% 🔺)	0.657s	36	1.31x

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.914s (-0.7%)	2.075s (-1.2%)	0.161s	44	1.00x
🐘 Postgres	Next.js (Turbopack)	1.925s	2.149s	0.225s	42	1.01x
🐘 Postgres	Express	1.968s (~)	2.316s (+2.6%)	0.348s	39	1.03x
💻 Local	Next.js (Turbopack)	2.737s	3.008s	0.271s	30	1.43x
💻 Local	Nitro	3.017s (-0.6%)	3.649s (-2.9%)	0.632s	25	1.58x
💻 Local	Express	3.020s (~)	3.610s (+0.7%)	0.589s	25	1.58x

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	3.864s	4.076s	0.212s	30	1.00x
🐘 Postgres	Nitro	3.866s (-5.8% 🟢)	4.042s (-12.2% 🟢)	0.176s	30	1.00x
🐘 Postgres	Express	4.204s (+5.4% 🔺)	5.011s (+14.7% 🔺)	0.807s	24	1.09x
💻 Local	Next.js (Turbopack)	8.536s	9.017s	0.481s	14	2.21x
💻 Local	Express	8.969s (-2.6%)	9.325s (-6.9% 🟢)	0.355s	13	2.32x
💻 Local	Nitro	9.222s (-0.8%)	9.942s (-0.8%)	0.720s	13	2.39x

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.247s	1.007s	0.760s	60	1.00x
🐘 Postgres	Nitro	0.284s (~)	1.006s (~)	0.722s	60	1.15x
🐘 Postgres	Express	0.294s (+4.1%)	1.007s (~)	0.713s	60	1.19x
💻 Local	Express	0.562s (~)	1.004s (~)	0.442s	60	2.27x
💻 Local	Next.js (Turbopack)	0.575s	1.004s	0.429s	60	2.33x
💻 Local	Nitro	0.580s (-4.1%)	1.004s (-1.7%)	0.425s	60	2.34x

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.488s	1.007s	0.519s	90	1.00x
🐘 Postgres	Express	0.488s (-4.3%)	1.007s (~)	0.519s	90	1.00x
🐘 Postgres	Nitro	0.496s (~)	1.006s (~)	0.510s	90	1.02x
💻 Local	Express	2.378s (-5.4% 🟢)	3.009s (~)	0.631s	30	4.88x
💻 Local	Nitro	2.571s (+1.3%)	3.009s (~)	0.438s	30	5.27x
💻 Local	Next.js (Turbopack)	2.576s	3.009s	0.433s	30	5.28x

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World	Framework	Workflow Time	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Express	0.792s (-3.3%)	1.008s (-0.9%)	0.217s	120	1.00x
🐘 Postgres	Nitro	0.796s (+0.7%)	1.007s (~)	0.211s	120	1.01x
🐘 Postgres	Next.js (Turbopack)	0.798s	1.015s	0.217s	119	1.01x
💻 Local	Next.js (Turbopack)	10.221s	10.940s	0.718s	11	12.91x
💻 Local	Express	10.431s (-6.8% 🟢)	11.028s (-7.6% 🟢)	0.597s	11	13.18x
💻 Local	Nitro	11.794s (+5.4% 🔺)	12.327s (+5.7% 🔺)	0.534s	10	14.90x

Stream Benchmarks(includes TTFB metrics)

workflow with stream

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
💻 Local	🥇 Next.js (Turbopack)	0.183s	1.003s	0.010s	1.016s	0.834s	10	1.00x
🐘 Postgres	Next.js (Turbopack)	0.190s	1.000s	0.001s	1.009s	0.819s	10	1.04x
🐘 Postgres	Nitro	0.203s (-0.8%)	0.996s (~)	0.001s (-33.3% 🟢)	1.008s (~)	0.805s	10	1.11x
💻 Local	Nitro	0.208s (-2.6%)	1.004s (~)	0.012s (-1.6%)	1.019s (~)	0.810s	10	1.14x
🐘 Postgres	Express	0.227s (+10.5% 🔺)	0.996s (~)	0.001s (-12.5% 🟢)	1.011s (~)	0.784s	10	1.24x
💻 Local	Express	0.248s (+24.5% 🔺)	1.004s (~)	0.020s (+67.8% 🔺)	1.027s (+0.8%)	0.779s	10	1.36x

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	0.619s (-0.7%)	1.026s (+1.9%)	0.004s (-5.8% 🟢)	1.046s (+2.3%)	0.427s	58	1.00x
🐘 Postgres	Express	0.627s (-0.5%)	1.005s (~)	0.012s (+205.3% 🔺)	1.030s (+0.6%)	0.403s	59	1.01x
🐘 Postgres	Next.js (Turbopack)	0.640s	1.044s	0.004s	1.058s	0.418s	57	1.03x
💻 Local	Next.js (Turbopack)	0.696s	1.012s	0.011s	1.026s	0.331s	59	1.12x
💻 Local	Nitro	0.747s (-10.9% 🟢)	1.012s (~)	0.010s (+8.2% 🔺)	1.023s (-8.3% 🟢)	0.276s	59	1.21x
💻 Local	Express	0.763s (+0.8%)	1.012s (-1.6%)	0.010s (+1.4%)	1.024s (-1.6%)	0.260s	59	1.23x

10 parallel streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Next.js (Turbopack)	0.926s	1.199s	0.000s	1.208s	0.282s	51	1.00x
🐘 Postgres	Nitro	0.955s (-1.4%)	1.168s (-6.4% 🟢)	0.000s (-52.9% 🟢)	1.193s (-5.2% 🟢)	0.238s	51	1.03x
🐘 Postgres	Express	0.967s (+0.6%)	1.246s (-2.5%)	0.000s (-52.1% 🟢)	1.259s (-3.7%)	0.292s	48	1.04x
💻 Local	Express	1.214s (-0.9%)	2.020s (~)	0.000s (-10.0% 🟢)	2.022s (~)	0.808s	30	1.31x
💻 Local	Nitro	1.233s (+0.8%)	2.021s (~)	0.000s (+333.3% 🔺)	2.023s (~)	0.790s	30	1.33x
💻 Local	Next.js (Turbopack)	1.313s	2.022s	0.000s	2.025s	0.712s	30	1.42x

fan-out fan-in 10 streams (1MB each)

💻 Local Development

World	Framework	Workflow Time	TTFB	Slurp	Wall Time	Overhead	Samples	vs Fastest
🐘 Postgres	🥇 Nitro	1.732s (-3.3%)	2.139s (~)	0.000s (-100.0% 🟢)	2.152s (-1.0%)	0.419s	28	1.00x
🐘 Postgres	Next.js (Turbopack)	1.803s	2.106s	0.000s	2.138s	0.334s	29	1.04x
🐘 Postgres	Express	1.817s (+2.6%)	2.261s (+3.8%)	0.000s (+Infinity% 🔺)	2.270s (+3.2%)	0.453s	27	1.05x
💻 Local	Express	3.438s (-0.9%)	4.032s (~)	0.001s (-33.3% 🟢)	4.035s (~)	0.597s	15	1.98x
💻 Local	Nitro	3.503s (+3.4%)	4.032s (~)	0.001s (~)	4.035s (~)	0.532s	15	2.02x
💻 Local	Next.js (Turbopack)	3.861s	4.235s	0.000s	4.239s	0.378s	15	2.23x

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World	🥇 Fastest Framework	Wins
💻 Local	Next.js (Turbopack)	15/21
🐘 Postgres	Next.js (Turbopack)	10/21

Fastest World by Framework

Winner determined by most benchmark wins

Framework	🥇 Fastest World	Wins
Express	🐘 Postgres	18/21
Next.js (Turbopack)	🐘 Postgres	17/21
Nitro	🐘 Postgres	18/21

Column Definitions

• Workflow Time: Runtime reported by workflow (completedAt - createdAt) - primary metric
• TTFB: Time to First Byte - time from workflow start until first stream byte received (stream benchmarks only)
• Slurp: Time from first byte to complete stream consumption (stream benchmarks only)
• Wall Time: Total testbench time (trigger workflow + poll for result)
• Overhead: Testbench overhead (Wall Time - Workflow Time)
• Samples: Number of benchmark iterations run
• vs Fastest: How much slower compared to the fastest configuration for this benchmark

Worlds:

• 💻 Local: In-memory filesystem world (local development)
• 🐘 Postgres: PostgreSQL database world (local development)
• ▲ Vercel: Vercel production/preview deployment
• 🌐 Turso: Community world (local development)
• 🌐 MongoDB: Community world (local development)
• 🌐 Redis: Community world (local development)
• 🌐 Jazz: Community world (local development)

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📋 View full workflow run

[VaguelySerious]

(AI) I'm not sure how https://github.com/vercel/front/pull/68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

[karthikscale3]

(AI) I'm not sure how vercel/front#68191 is a mirror of this, but as long as both ends work, LGTM. I haven't tried it out locally, so I'd want to re-test once the live deployment is back online, or before release

Front to close but not exactly 1:1. I will make a separate PR to close the gap.