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refactor(swc-plugin): remove client transform mode, merge into step mode#1686

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TooTallNate merged 3 commits intomainfrom
nr/remove-client-mode
Apr 16, 2026
Merged

refactor(swc-plugin): remove client transform mode, merge into step mode#1686
TooTallNate merged 3 commits intomainfrom
nr/remove-client-mode

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@TooTallNate TooTallNate commented Apr 10, 2026 •
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Summary

  • Remove the client transform mode from the SWC compiler plugin, merging it into step mode
  • The plugin now has 3 modes (Step, Workflow, Detect) instead of 4
  • All integrations that previously used mode: 'client' now use mode: 'step'

Motivation

The client and step modes were nearly identical — both preserved step function bodies, replaced workflow bodies with throw stubs, and emitted the same JSON manifest. The only differences were:

  1. Registration mechanism: client used a simple .stepId property assignment; step used an IIFE with global Map registration
  2. Dead code elimination: client ran DCE; step did not
  3. Object property step call sites: client replaced inline functions with hoisted variable references; step kept the original inline copy

None of these differences were fundamentally necessary. Merging them simplifies the codebase by ~450 lines of Rust and removes 67 test fixture files.

What changed in step mode

  • DCE now runs — removes dead code just like it did in client mode, preserving step bodies and their dependencies
  • Object property steps use hoisted variable references at call sites so .stepId is accessible on the same function object
  • IIFE registration is unchanged — all step functions are registered in the global Map

Changed packages

Package Change
@workflow/swc-plugin Removed Client variant from TransformMode enum, ~450 lines of client-specific match arms
@workflow/next loader.ts now always uses mode: 'step'
@workflow/builders base-builder.ts, apply-swc-transform.ts, swc-esbuild-plugin.ts — removed 'client' from types and mode values
@workflow/cli Removed 'client' from transform command options
@workflow/rollup Changed mode: 'client' to mode: 'step'
@workflow/nest Changed mode: 'client' to mode: 'step'
@workflow/swc-playground-wasm Removed client output from batch transform

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🧪 E2E Test Results

❌ Some tests failed

Summary

Passed Failed Skipped Total
✅ ▲ Vercel Production 923 0 67 990
✅ 💻 Local Development 994 0 86 1080
✅ 📦 Local Production 994 0 86 1080
✅ 🐘 Local Postgres 994 0 86 1080
✅ 🪟 Windows 90 0 0 90
❌ 🌍 Community Worlds 133 98 0 231
✅ 📋 Other 252 0 18 270
Total 4380 98 343 4821

❌ Failed Tests

🌍 Community Worlds (98 failed)

mongodb (15 failed):

  • readableStreamWorkflow | wrun_01KPC49NNZW9YY0KB64K6VSQHB
  • hookWorkflow is not resumable via public webhook endpoint | wrun_01KPC4AC42WBKTER23K36G2ZAT
  • webhookWorkflow | wrun_01KPC4AMQBQNMGQ4RMS3XNMX4K
  • outputStreamWorkflow no startIndex (reads all chunks)
  • outputStreamWorkflow positive startIndex (skips first chunk)
  • outputStreamWorkflow negative startIndex (reads from end)
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns correct index after stream completes
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns -1 before any chunks are written
  • outputStreamWorkflow - getTailIndex and getChunks getChunks returns same content as reading the stream
  • outputStreamInsideStepWorkflow - getWritable() called inside step functions | wrun_01KPC4DTF69CSG9SGAXK101SCA
  • fetchWorkflow | wrun_01KPC4E7RZPD314K6BKBYSXGT0
  • concurrent hook token conflict - two workflows cannot use the same hook token simultaneously | wrun_01KPC4JB5B6GKYQ4NA68WW9JFN
  • health check (queue-based) - workflow and step endpoints respond to health check messages
  • health check (CLI) - workflow health command reports healthy endpoints
  • resilient start: addTenWorkflow completes when run_created returns 500 | wrun_01KPC4RK5F4H2A50VNYVKYDZYH

redis (15 failed):

  • readableStreamWorkflow | wrun_01KPC49NNZW9YY0KB64K6VSQHB
  • hookWorkflow is not resumable via public webhook endpoint | wrun_01KPC4AC42WBKTER23K36G2ZAT
  • webhookWorkflow | wrun_01KPC4AMQBQNMGQ4RMS3XNMX4K
  • outputStreamWorkflow no startIndex (reads all chunks)
  • outputStreamWorkflow positive startIndex (skips first chunk)
  • outputStreamWorkflow negative startIndex (reads from end)
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns correct index after stream completes
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns -1 before any chunks are written
  • outputStreamWorkflow - getTailIndex and getChunks getChunks returns same content as reading the stream
  • outputStreamInsideStepWorkflow - getWritable() called inside step functions | wrun_01KPC4DTF69CSG9SGAXK101SCA
  • fetchWorkflow | wrun_01KPC4E7RZPD314K6BKBYSXGT0
  • concurrent hook token conflict - two workflows cannot use the same hook token simultaneously | wrun_01KPC4JB5B6GKYQ4NA68WW9JFN
  • health check (queue-based) - workflow and step endpoints respond to health check messages
  • health check (CLI) - workflow health command reports healthy endpoints
  • resilient start: addTenWorkflow completes when run_created returns 500 | wrun_01KPC4RK5F4H2A50VNYVKYDZYH

turso (68 failed):

  • addTenWorkflow | wrun_01KPC494JMXC2S698ZCV0Z1A6J
  • addTenWorkflow | wrun_01KPC494JMXC2S698ZCV0Z1A6J
  • wellKnownAgentWorkflow (.well-known/agent) | wrun_01KPC4AGDR3W8R8RXJT4B0AAA1
  • should work with react rendering in step
  • promiseAllWorkflow | wrun_01KPC49C06JB8S19BQWT39ZGY3
  • promiseRaceWorkflow | wrun_01KPC49GDW34C2CAXQED5GQ5HD
  • promiseAnyWorkflow | wrun_01KPC49JF67R2674SKNT0B531G
  • importedStepOnlyWorkflow | wrun_01KPC4ATXWJTKEXDX5AZ5QQ00W
  • readableStreamWorkflow | wrun_01KPC49NNZW9YY0KB64K6VSQHB
  • hookWorkflow | wrun_01KPC4A08KB58ENADF0R99QWRK
  • hookWorkflow is not resumable via public webhook endpoint | wrun_01KPC4AC42WBKTER23K36G2ZAT
  • webhookWorkflow | wrun_01KPC4AMQBQNMGQ4RMS3XNMX4K
  • sleepingWorkflow | wrun_01KPC4ATTECEVNJQ03J54ZFBVM
  • parallelSleepWorkflow | wrun_01KPC4B757NA7GCQPA911F04ZY
  • nullByteWorkflow | wrun_01KPC4BBA9SENAQ2793T64G2HD
  • workflowAndStepMetadataWorkflow | wrun_01KPC4BD6G7ZV66PGPFA4QPD88
  • outputStreamWorkflow no startIndex (reads all chunks)
  • outputStreamWorkflow positive startIndex (skips first chunk)
  • outputStreamWorkflow negative startIndex (reads from end)
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns correct index after stream completes
  • outputStreamWorkflow - getTailIndex and getChunks getTailIndex returns -1 before any chunks are written
  • outputStreamWorkflow - getTailIndex and getChunks getChunks returns same content as reading the stream
  • outputStreamInsideStepWorkflow - getWritable() called inside step functions | wrun_01KPC4DTF69CSG9SGAXK101SCA
  • fetchWorkflow | wrun_01KPC4E7RZPD314K6BKBYSXGT0
  • promiseRaceStressTestWorkflow | wrun_01KPC4EB2BAVKDBD6MS0ZQ6EA2
  • error handling error propagation workflow errors nested function calls preserve message and stack trace
  • error handling error propagation workflow errors cross-file imports preserve message and stack trace
  • error handling error propagation step errors basic step error preserves message and stack trace
  • error handling error propagation step errors cross-file step error preserves message and function names in stack
  • error handling retry behavior regular Error retries until success
  • error handling retry behavior FatalError fails immediately without retries
  • error handling retry behavior RetryableError respects custom retryAfter delay
  • error handling retry behavior maxRetries=0 disables retries
  • error handling catchability FatalError can be caught and detected with FatalError.is()
  • error handling not registered WorkflowNotRegisteredError fails the run when workflow does not exist
  • error handling not registered StepNotRegisteredError fails the step but workflow can catch it
  • error handling not registered StepNotRegisteredError fails the run when not caught in workflow
  • hookCleanupTestWorkflow - hook token reuse after workflow completion | wrun_01KPC4HQX6G61Z1EVG4JNP930D
  • concurrent hook token conflict - two workflows cannot use the same hook token simultaneously | wrun_01KPC4JB5B6GKYQ4NA68WW9JFN
  • hookDisposeTestWorkflow - hook token reuse after explicit disposal while workflow still running | wrun_01KPC4JYZ7FS1R557Y32RKYX4X
  • stepFunctionPassingWorkflow - step function references can be passed as arguments (without closure vars) | wrun_01KPC4KHC0489EJS7TH6H8C1FP
  • stepFunctionWithClosureWorkflow - step function with closure variables passed as argument | wrun_01KPC4KSEB6GVW9G0XXRPWE3J8
  • closureVariableWorkflow - nested step functions with closure variables | wrun_01KPC4KYK1XY4DHRRTHJ2T1M21
  • spawnWorkflowFromStepWorkflow - spawning a child workflow using start() inside a step | wrun_01KPC4M0KZH3ASYEG5R6JBWENC
  • runClassSerializationWorkflow - Run instances serialize across workflow/step boundaries | wrun_01KPC4MB45KDRW8N8D6WN06XEQ
  • health check (queue-based) - workflow and step endpoints respond to health check messages
  • health check (CLI) - workflow health command reports healthy endpoints
  • pathsAliasWorkflow - TypeScript path aliases resolve correctly | wrun_01KPC4MS5KHDWDK2F94N22ZFQW
  • Calculator.calculate - static workflow method using static step methods from another class | wrun_01KPC4MZ6PEQNSM56KWF9FJX1E
  • AllInOneService.processNumber - static workflow method using sibling static step methods | wrun_01KPC4N5GZH4ZFPZPW62YEP6KV
  • ChainableService.processWithThis - static step methods using this to reference the class | wrun_01KPC4NBR68W7CSHPE7R7M4EK3
  • thisSerializationWorkflow - step function invoked with .call() and .apply() | wrun_01KPC4NHS0ARKDVB77N2MX3CAC
  • customSerializationWorkflow - custom class serialization with WORKFLOW_SERIALIZE/WORKFLOW_DESERIALIZE | wrun_01KPC4NQW6FWS4MXN0R48DA026
  • instanceMethodStepWorkflow - instance methods with "use step" directive | wrun_01KPC4NZ0FPXKMQX3X2CQ04PBG
  • crossContextSerdeWorkflow - classes defined in step code are deserializable in workflow context | wrun_01KPC4P9N2G26Q97QRYDQ0Y9YK
  • stepFunctionAsStartArgWorkflow - step function reference passed as start() argument | wrun_01KPC4PGZWQE4GQXWWGY0QH4J7
  • cancelRun - cancelling a running workflow | wrun_01KPC4PR5VZ7PAPEH1FB5DTEBH
  • cancelRun via CLI - cancelling a running workflow | wrun_01KPC4Q0WDH365KZXRFP7S3YXX
  • pages router addTenWorkflow via pages router
  • pages router promiseAllWorkflow via pages router
  • pages router sleepingWorkflow via pages router
  • hookWithSleepWorkflow - hook payloads delivered correctly with concurrent sleep | wrun_01KPC4QC7VC0XAK4HG5DG72TYK
  • sleepInLoopWorkflow - sleep inside loop with steps actually delays each iteration | wrun_01KPC4QZCT792E4TFQ8YN5Q6BV
  • sleepWithSequentialStepsWorkflow - sequential steps work with concurrent sleep (control) | wrun_01KPC4R9ARDE36CTKSVKBD0BV7
  • importMetaUrlWorkflow - import.meta.url is available in step bundles | wrun_01KPC4RF7T0AJ9JST4ZEVXQBYY
  • metadataFromHelperWorkflow - getWorkflowMetadata/getStepMetadata work from module-level helper (#1577) | wrun_01KPC4RH3HCX2FND5E2Q3889HY
  • resilient start: addTenWorkflow completes when run_created returns 500 | wrun_01KPC4RK5F4H2A50VNYVKYDZYH
  • getterStepWorkflow - getter functions with "use step" directive | wrun_01KPC4RP4RG6MQ9C0QJJXPXG6F

Details by Category

✅ ▲ Vercel Production
App Passed Failed Skipped
✅ astro 83 0 7
✅ example 83 0 7
✅ express 83 0 7
✅ fastify 83 0 7
✅ hono 83 0 7
✅ nextjs-turbopack 88 0 2
✅ nextjs-webpack 88 0 2
✅ nitro 83 0 7
✅ nuxt 83 0 7
✅ sveltekit 83 0 7
✅ vite 83 0 7
✅ 💻 Local Development
App Passed Failed Skipped
✅ astro-stable 84 0 6
✅ express-stable 84 0 6
✅ fastify-stable 84 0 6
✅ hono-stable 84 0 6
✅ nextjs-turbopack-canary 71 0 19
✅ nextjs-turbopack-stable 90 0 0
✅ nextjs-webpack-canary 71 0 19
✅ nextjs-webpack-stable 90 0 0
✅ nitro-stable 84 0 6
✅ nuxt-stable 84 0 6
✅ sveltekit-stable 84 0 6
✅ vite-stable 84 0 6
✅ 📦 Local Production
App Passed Failed Skipped
✅ astro-stable 84 0 6
✅ express-stable 84 0 6
✅ fastify-stable 84 0 6
✅ hono-stable 84 0 6
✅ nextjs-turbopack-canary 71 0 19
✅ nextjs-turbopack-stable 90 0 0
✅ nextjs-webpack-canary 71 0 19
✅ nextjs-webpack-stable 90 0 0
✅ nitro-stable 84 0 6
✅ nuxt-stable 84 0 6
✅ sveltekit-stable 84 0 6
✅ vite-stable 84 0 6
✅ 🐘 Local Postgres
App Passed Failed Skipped
✅ astro-stable 84 0 6
✅ express-stable 84 0 6
✅ fastify-stable 84 0 6
✅ hono-stable 84 0 6
✅ nextjs-turbopack-canary 71 0 19
✅ nextjs-turbopack-stable 90 0 0
✅ nextjs-webpack-canary 71 0 19
✅ nextjs-webpack-stable 90 0 0
✅ nitro-stable 84 0 6
✅ nuxt-stable 84 0 6
✅ sveltekit-stable 84 0 6
✅ vite-stable 84 0 6
✅ 🪟 Windows
App Passed Failed Skipped
✅ nextjs-turbopack 90 0 0
❌ 🌍 Community Worlds
App Passed Failed Skipped
✅ mongodb-dev 6 0 0
❌ mongodb 56 15 0
✅ redis-dev 6 0 0
❌ redis 56 15 0
✅ turso-dev 6 0 0
❌ turso 3 68 0
✅ 📋 Other
App Passed Failed Skipped
✅ e2e-local-dev-nest-stable 84 0 6
✅ e2e-local-postgres-nest-stable 84 0 6
✅ e2e-local-prod-nest-stable 84 0 6

📋 View full workflow run

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📊 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 🥇 Express 0.044s (-0.9%) 1.005s (~) 0.961s 10 1.00x
💻 Local Nitro 0.044s (+1.9%) 1.005s (~) 0.961s 10 1.00x
💻 Local Next.js (Turbopack) 0.047s 1.005s 0.958s 10 1.08x
🐘 Postgres Nitro 0.053s (-44.2% 🟢) 1.011s (-3.1%) 0.957s 10 1.21x
🐘 Postgres Next.js (Turbopack) 0.056s 1.010s 0.954s 10 1.27x
🐘 Postgres Express 0.057s (-1.6%) 1.011s (~) 0.954s 10 1.30x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 0.232s (-43.5% 🟢) 2.120s (-15.5% 🟢) 1.888s 10 1.00x
▲ Vercel Next.js (Turbopack) 0.265s (+5.5% 🔺) 2.026s (-13.2% 🟢) 1.760s 10 1.15x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 1 step

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
💻 Local 🥇 Next.js (Turbopack) 1.122s 2.006s 0.884s 10 1.00x
🐘 Postgres Nitro 1.124s (-1.4%) 2.009s (~) 0.885s 10 1.00x
💻 Local Nitro 1.131s (~) 2.006s (~) 0.875s 10 1.01x
💻 Local Express 1.134s (+0.8%) 2.007s (~) 0.872s 10 1.01x
🐘 Postgres Next.js (Turbopack) 1.136s 2.011s 0.875s 10 1.01x
🐘 Postgres Express 1.154s (+0.6%) 2.010s (~) 0.856s 10 1.03x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 1.948s (-50.0% 🟢) 3.730s (-36.9% 🟢) 1.782s 10 1.00x
▲ Vercel Next.js (Turbopack) 1.978s (-2.8%) 3.253s (-15.1% 🟢) 1.275s 10 1.02x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 10 sequential steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 10.738s (-1.2%) 11.025s (~) 0.287s 3 1.00x
💻 Local Next.js (Turbopack) 10.830s 11.023s 0.193s 3 1.01x
🐘 Postgres Express 10.894s (-0.6%) 11.025s (~) 0.131s 3 1.01x
💻 Local Nitro 10.920s (~) 11.022s (~) 0.102s 3 1.02x
🐘 Postgres Next.js (Turbopack) 10.927s 11.018s 0.091s 3 1.02x
💻 Local Express 10.947s (~) 11.024s (~) 0.078s 3 1.02x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 17.104s (-27.9% 🟢) 19.463s (-22.5% 🟢) 2.360s 2 1.00x
▲ Vercel Next.js (Turbopack) 17.338s (~) 18.457s (-4.9%) 1.119s 2 1.01x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 25 sequential steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 14.143s (-3.1%) 15.027s (~) 0.884s 4 1.00x
🐘 Postgres Next.js (Turbopack) 14.476s 15.029s 0.553s 4 1.02x
💻 Local Next.js (Turbopack) 14.575s 15.028s 0.454s 4 1.03x
🐘 Postgres Express 14.575s (~) 15.026s (~) 0.451s 4 1.03x
💻 Local Nitro 14.924s (-0.9%) 15.029s (-6.2% 🟢) 0.104s 4 1.06x
💻 Local Express 15.108s (+0.9%) 16.032s (+6.7% 🔺) 0.924s 4 1.07x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 32.373s (-49.8% 🟢) 34.553s (-48.1% 🟢) 2.179s 2 1.00x
▲ Vercel Next.js (Turbopack) 33.318s (-36.6% 🟢) 34.394s (-37.0% 🟢) 1.076s 2 1.03x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 50 sequential steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 13.235s (-5.2% 🟢) 13.880s (-3.0%) 0.645s 7 1.00x
🐘 Postgres Express 13.877s (-0.9%) 14.022s (-3.9%) 0.145s 7 1.05x
🐘 Postgres Next.js (Turbopack) 13.974s 14.455s 0.481s 7 1.06x
💻 Local Next.js (Turbopack) 15.884s 16.196s 0.312s 6 1.20x
💻 Local Nitro 16.479s (-1.8%) 17.030s (~) 0.552s 6 1.25x
💻 Local Express 16.807s (+1.2%) 17.031s (~) 0.224s 6 1.27x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 55.193s (-86.9% 🟢) 57.639s (-86.4% 🟢) 2.446s 2 1.00x
▲ Vercel Next.js (Turbopack) 59.836s (-84.8% 🟢) 60.966s (-84.6% 🟢) 1.130s 2 1.08x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.all with 10 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 1.223s (-4.1%) 2.009s (~) 0.787s 15 1.00x
🐘 Postgres Express 1.251s (-0.8%) 2.010s (~) 0.760s 15 1.02x
🐘 Postgres Next.js (Turbopack) 1.252s 2.009s 0.756s 15 1.02x
💻 Local Next.js (Turbopack) 1.488s 2.005s 0.517s 15 1.22x
💻 Local Nitro 1.498s (-8.2% 🟢) 2.006s (-3.3%) 0.507s 15 1.23x
💻 Local Express 1.528s (+2.6%) 2.006s (~) 0.477s 15 1.25x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 2.389s (-15.2% 🟢) 3.777s (-12.6% 🟢) 1.388s 9 1.00x
▲ Vercel Next.js (Turbopack) 2.457s (-27.7% 🟢) 3.702s (-25.0% 🟢) 1.244s 9 1.03x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.all with 25 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 2.320s (-1.3%) 3.009s (~) 0.689s 10 1.00x
🐘 Postgres Express 2.335s (-1.1%) 3.008s (~) 0.674s 10 1.01x
🐘 Postgres Next.js (Turbopack) 2.393s 3.010s 0.617s 10 1.03x
💻 Local Next.js (Turbopack) 2.874s 3.309s 0.435s 10 1.24x
💻 Local Nitro 2.898s (-7.8% 🟢) 3.453s (-11.1% 🟢) 0.555s 9 1.25x
💻 Local Express 3.040s (+3.0%) 3.759s (+8.8% 🔺) 0.719s 8 1.31x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 2.873s (-29.1% 🟢) 4.645s (-21.5% 🟢) 1.772s 7 1.00x
▲ Vercel Next.js (Turbopack) 3.637s (-48.8% 🟢) 5.185s (-41.8% 🟢) 1.548s 6 1.27x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.all with 50 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 3.426s (-1.5%) 4.010s (~) 0.583s 8 1.00x
🐘 Postgres Express 3.459s (-0.8%) 4.010s (~) 0.551s 8 1.01x
🐘 Postgres Next.js (Turbopack) 3.689s 4.010s 0.321s 8 1.08x
💻 Local Next.js (Turbopack) 7.497s 8.019s 0.522s 4 2.19x
💻 Local Nitro 8.051s (-3.6%) 8.772s (-2.8%) 0.721s 4 2.35x
💻 Local Express 8.203s (-1.6%) 9.020s (~) 0.817s 4 2.39x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 3.559s (+1.0%) 5.051s (-8.7% 🟢) 1.492s 6 1.00x
▲ Vercel Next.js (Turbopack) 6.803s (-23.7% 🟢) 8.029s (-26.7% 🟢) 1.226s 4 1.91x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.race with 10 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 1.209s (-3.8%) 2.009s (~) 0.800s 15 1.00x
🐘 Postgres Next.js (Turbopack) 1.228s 2.010s 0.782s 15 1.02x
🐘 Postgres Express 1.267s (+0.8%) 2.008s (~) 0.741s 15 1.05x
💻 Local Nitro 1.515s (-18.8% 🟢) 2.005s (-14.3% 🟢) 0.490s 15 1.25x
💻 Local Next.js (Turbopack) 1.531s 2.006s 0.475s 15 1.27x
💻 Local Express 1.544s (-18.5% 🟢) 2.006s (-15.1% 🟢) 0.462s 15 1.28x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 2.037s (-17.2% 🟢) 3.718s (-10.8% 🟢) 1.681s 9 1.00x
▲ Vercel Next.js (Turbopack) 2.401s (-18.1% 🟢) 3.792s (-18.3% 🟢) 1.391s 8 1.18x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.race with 25 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 2.327s (-0.5%) 3.010s (~) 0.683s 10 1.00x
🐘 Postgres Express 2.336s (~) 3.010s (~) 0.674s 10 1.00x
🐘 Postgres Next.js (Turbopack) 2.393s 3.008s 0.616s 10 1.03x
💻 Local Next.js (Turbopack) 2.787s 3.452s 0.665s 9 1.20x
💻 Local Nitro 2.836s (-7.5% 🟢) 3.309s (-14.9% 🟢) 0.473s 10 1.22x
💻 Local Express 3.261s (+4.1%) 4.011s (+6.6% 🔺) 0.750s 8 1.40x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 2.598s (-19.7% 🟢) 4.042s (-20.4% 🟢) 1.444s 8 1.00x
▲ Vercel Next.js (Turbopack) 2.787s (-11.3% 🟢) 4.209s (-6.9% 🟢) 1.422s 8 1.07x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Promise.race with 50 concurrent steps

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 3.456s (-0.7%) 4.011s (~) 0.555s 8 1.00x
🐘 Postgres Express 3.480s (-0.5%) 4.010s (~) 0.530s 8 1.01x
🐘 Postgres Next.js (Turbopack) 3.617s 4.012s 0.395s 8 1.05x
💻 Local Next.js (Turbopack) 7.510s 8.018s 0.507s 4 2.17x
💻 Local Nitro 8.662s (-5.3% 🟢) 9.275s (-7.5% 🟢) 0.613s 4 2.51x
💻 Local Express 8.993s (+2.2%) 9.273s (~) 0.279s 4 2.60x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 2.764s (-45.7% 🟢) 4.520s (-33.7% 🟢) 1.756s 7 1.00x
▲ Vercel Next.js (Turbopack) 4.827s (-28.6% 🟢) 6.399s (-25.1% 🟢) 1.572s 5 1.75x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 10 sequential data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.624s (-23.9% 🟢) 1.006s (~) 0.382s 60 1.00x
🐘 Postgres Next.js (Turbopack) 0.786s 1.023s 0.237s 59 1.26x
🐘 Postgres Express 0.808s (-3.7%) 1.022s (~) 0.214s 59 1.29x
💻 Local Next.js (Turbopack) 0.852s 1.039s 0.187s 58 1.36x
💻 Local Nitro 0.988s (+0.8%) 1.158s (+5.9% 🔺) 0.170s 52 1.58x
💻 Local Express 0.989s (~) 1.250s (+16.1% 🔺) 0.261s 49 1.58x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 10.124s (-54.1% 🟢) 12.026s (-49.9% 🟢) 1.902s 5 1.00x
▲ Vercel Next.js (Turbopack) 11.473s (-20.9% 🟢) 12.880s (-19.9% 🟢) 1.407s 5 1.13x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 25 sequential data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 1.503s (-22.0% 🟢) 2.007s (-4.4%) 0.504s 45 1.00x
🐘 Postgres Express 1.918s (-3.0%) 2.100s (-7.0% 🟢) 0.183s 43 1.28x
🐘 Postgres Next.js (Turbopack) 1.959s 2.203s 0.244s 41 1.30x
💻 Local Next.js (Turbopack) 2.627s 3.008s 0.381s 30 1.75x
💻 Local Nitro 3.004s (-1.0%) 3.508s (-6.7% 🟢) 0.504s 26 2.00x
💻 Local Express 3.039s (+0.8%) 3.690s (+2.9%) 0.651s 25 2.02x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Next.js (Turbopack) 32.147s (-35.5% 🟢) 33.634s (-35.0% 🟢) 1.487s 3 1.00x
▲ Vercel Nitro 37.762s (-4.4%) 39.759s (-3.7%) 1.997s 3 1.17x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Next.js (Turbopack) | Nitro

workflow with 50 sequential data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 3.164s (-22.9% 🟢) 3.824s (-16.9% 🟢) 0.660s 32 1.00x
🐘 Postgres Next.js (Turbopack) 3.883s 4.147s 0.264s 29 1.23x
🐘 Postgres Express 3.890s (-2.5%) 4.110s (-5.9% 🟢) 0.219s 30 1.23x
💻 Local Next.js (Turbopack) 8.566s 9.018s 0.452s 14 2.71x
💻 Local Express 9.269s (+0.6%) 10.019s (~) 0.749s 12 2.93x
💻 Local Nitro 9.497s (+2.1%) 10.101s (+0.8%) 0.604s 12 3.00x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 77.978s (-19.5% 🟢) 79.827s (-18.9% 🟢) 1.850s 2 1.00x
▲ Vercel Next.js (Turbopack) 89.255s (-16.7% 🟢) 90.555s (-16.9% 🟢) 1.300s 2 1.14x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 10 concurrent data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.235s (-16.9% 🟢) 1.007s (~) 0.772s 60 1.00x
🐘 Postgres Next.js (Turbopack) 0.256s 1.008s 0.751s 60 1.09x
🐘 Postgres Express 0.285s (+0.8%) 1.007s (~) 0.723s 60 1.21x
💻 Local Next.js (Turbopack) 0.575s 1.004s 0.430s 60 2.44x
💻 Local Express 0.615s (+9.8% 🔺) 1.022s (+1.7%) 0.407s 59 2.61x
💻 Local Nitro 0.668s (+10.5% 🔺) 1.095s (+7.2% 🔺) 0.427s 55 2.84x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 1.858s (+11.9% 🔺) 3.442s (+2.7%) 1.584s 18 1.00x
▲ Vercel Next.js (Turbopack) 5.248s (+159.5% 🔺) 6.681s (+76.1% 🔺) 1.432s 9 2.82x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 25 concurrent data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.383s (-22.8% 🟢) 1.006s (~) 0.623s 90 1.00x
🐘 Postgres Express 0.488s (-4.2%) 1.007s (~) 0.519s 90 1.27x
🐘 Postgres Next.js (Turbopack) 0.503s 1.007s 0.503s 90 1.31x
💻 Local Nitro 2.463s (-3.0%) 3.009s (~) 0.546s 30 6.43x
💻 Local Express 2.591s (+3.1%) 3.009s (~) 0.418s 30 6.76x
💻 Local Next.js (Turbopack) 2.594s 3.008s 0.414s 30 6.77x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 5.501s (+70.5% 🔺) 7.445s (+54.4% 🔺) 1.944s 13 1.00x
▲ Vercel Next.js (Turbopack) 8.725s (+146.8% 🔺) 10.373s (+99.7% 🔺) 1.648s 9 1.59x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

workflow with 50 concurrent data payload steps (10KB)

💻 Local Development

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.614s (-22.3% 🟢) 1.007s (~) 0.393s 120 1.00x
🐘 Postgres Next.js (Turbopack) 0.800s 1.008s 0.208s 120 1.30x
🐘 Postgres Express 0.802s (-2.0%) 1.016s (~) 0.214s 119 1.31x
💻 Local Next.js (Turbopack) 10.669s 11.392s 0.723s 11 17.38x
💻 Local Nitro 10.798s (-3.5%) 11.300s (-3.1%) 0.501s 11 17.59x
💻 Local Express 11.456s (+2.4%) 12.032s (+0.8%) 0.576s 10 18.66x

▲ Production (Vercel)

World Framework Workflow Time Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 9.424s (+22.0% 🔺) 11.667s (+24.1% 🔺) 2.243s 11 1.00x
▲ Vercel Next.js (Turbopack) 15.660s (+51.6% 🔺) 16.985s (+38.2% 🔺) 1.325s 8 1.66x
▲ Vercel Express ⚠️ missing - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

Stream Benchmarks (includes TTFB metrics)
workflow with stream

💻 Local Development

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.177s (-13.8% 🟢) 0.997s (~) 0.001s (-20.0% 🟢) 1.011s (~) 0.834s 10 1.00x
💻 Local Next.js (Turbopack) 0.188s 1.003s 0.011s 1.017s 0.830s 10 1.06x
🐘 Postgres Next.js (Turbopack) 0.192s 1.001s 0.002s 1.011s 0.818s 10 1.09x
💻 Local Nitro 0.201s (-6.2% 🟢) 1.004s (~) 0.011s (-9.6% 🟢) 1.017s (~) 0.817s 10 1.13x
💻 Local Express 0.204s (+2.5%) 1.004s (~) 0.013s (+8.3% 🔺) 1.020s (~) 0.816s 10 1.15x
🐘 Postgres Express 0.204s (~) 1.001s (~) 0.002s (+6.2% 🔺) 1.011s (~) 0.806s 10 1.16x

▲ Production (Vercel)

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Next.js (Turbopack) 1.554s (-77.3% 🟢) 2.748s (-68.2% 🟢) 0.996s (+57.7% 🔺) 4.134s (-57.8% 🟢) 2.581s 10 1.00x
▲ Vercel Nitro 1.705s (-55.5% 🟢) 2.818s (-46.6% 🟢) 1.037s (+39.8% 🔺) 4.300s (-33.7% 🟢) 2.594s 10 1.10x
▲ Vercel Express ⚠️ missing - - - - -

🔍 Observability: Next.js (Turbopack) | Nitro

stream pipeline with 5 transform steps (1MB)

💻 Local Development

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 0.531s (-14.9% 🟢) 1.008s (~) 0.004s (-14.3% 🟢) 1.022s (~) 0.491s 59 1.00x
🐘 Postgres Express 0.607s (-3.6%) 1.006s (~) 0.004s (+3.1%) 1.023s (~) 0.416s 59 1.14x
🐘 Postgres Next.js (Turbopack) 0.617s 1.008s 0.003s 1.020s 0.402s 59 1.16x
💻 Local Nitro 0.742s (-11.6% 🟢) 1.012s (~) 0.009s (-2.5%) 1.023s (-8.3% 🟢) 0.281s 59 1.40x
💻 Local Next.js (Turbopack) 0.806s 1.011s 0.013s 1.120s 0.313s 54 1.52x
💻 Local Express 0.956s (+26.2% 🔺) 1.012s (-1.6%) 0.010s (+5.4% 🔺) 1.229s (+18.2% 🔺) 0.273s 49 1.80x

▲ Production (Vercel)

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 4.889s (-83.4% 🟢) 6.748s (-78.1% 🟢) 0.465s (+315.1% 🔺) 7.635s (-76.0% 🟢) 2.746s 8 1.00x
▲ Vercel Next.js (Turbopack) 14.674s (-13.3% 🟢) 15.526s (-14.9% 🟢) 0.211s (~) 16.076s (-15.1% 🟢) 1.403s 5 3.00x
▲ Vercel Express ⚠️ missing - - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

10 parallel streams (1MB each)

💻 Local Development

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Next.js (Turbopack) 0.938s 1.112s 0.000s 1.119s 0.182s 54 1.00x
🐘 Postgres Nitro 0.944s (-2.6%) 1.177s (-5.7% 🟢) 0.000s (+41.2% 🔺) 1.190s (-5.4% 🟢) 0.246s 51 1.01x
🐘 Postgres Express 0.974s (+1.4%) 1.219s (-4.6%) 0.000s (+87.8% 🔺) 1.243s (-4.9%) 0.269s 49 1.04x
💻 Local Nitro 1.214s (-0.7%) 2.021s (~) 0.000s (+33.3% 🔺) 2.022s (~) 0.808s 30 1.30x
💻 Local Express 1.238s (+1.0%) 2.020s (~) 0.000s (-10.0% 🟢) 2.022s (~) 0.785s 30 1.32x
💻 Local Next.js (Turbopack) 1.296s 2.019s 0.000s 2.023s 0.727s 30 1.38x

▲ Production (Vercel)

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Nitro 6.050s (+98.3% 🔺) 7.665s (+74.5% 🔺) 0.000s (-100.0% 🟢) 8.112s (+68.7% 🔺) 2.062s 8 1.00x
▲ Vercel Next.js (Turbopack) 7.695s (-24.4% 🟢) 7.641s (-33.7% 🟢) 0.000s (NaN%) 9.028s (-25.1% 🟢) 1.333s 7 1.27x
▲ Vercel Express ⚠️ missing - - - - -

🔍 Observability: Nitro | Next.js (Turbopack)

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

💻 Local Development

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
🐘 Postgres 🥇 Nitro 1.720s (-4.0%) 2.104s (-1.7%) 0.000s (+93.1% 🔺) 2.112s (-2.9%) 0.392s 29 1.00x
🐘 Postgres Express 1.727s (-2.5%) 2.104s (-3.4%) 0.000s (NaN%) 2.113s (-3.9%) 0.386s 29 1.00x
🐘 Postgres Next.js (Turbopack) 1.888s 2.182s 0.000s 2.189s 0.301s 28 1.10x
💻 Local Nitro 3.502s (+3.4%) 4.035s (~) 0.001s (+50.0% 🔺) 4.038s (~) 0.536s 15 2.04x
💻 Local Express 3.589s (+3.5%) 4.030s (~) 0.000s (-58.3% 🟢) 4.033s (~) 0.444s 15 2.09x
💻 Local Next.js (Turbopack) 3.746s 4.166s 0.000s 4.170s 0.424s 15 2.18x

▲ Production (Vercel)

World Framework Workflow Time TTFB Slurp Wall Time Overhead Samples vs Fastest
▲ Vercel 🥇 Next.js (Turbopack) 5.451s (-3.0%) 6.756s (-3.2%) 0.000s (-100.0% 🟢) 7.096s (-5.9% 🟢) 1.645s 9 1.00x
▲ Vercel Nitro 8.938s (+118.3% 🔺) 10.290s (+91.5% 🔺) 0.000s (-100.0% 🟢) 10.758s (+85.7% 🔺) 1.819s 6 1.64x
▲ Vercel Express ⚠️ missing - - - - -

🔍 Observability: Next.js (Turbopack) | Nitro

Summary

Fastest Framework by World

Winner determined by most benchmark wins

World 🥇 Fastest Framework Wins
💻 Local Next.js (Turbopack) 15/21
🐘 Postgres Nitro 20/21
▲ Vercel Nitro 18/21
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 19/21
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

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🦋 Changeset detected

Latest commit: dc6415b

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

This PR includes changesets to release 18 packages
Name Type
@workflow/swc-plugin Major
@workflow/builders Patch
@workflow/cli Patch
@workflow/next Patch
@workflow/rollup Patch
@workflow/nest Patch
@workflow/astro Patch
@workflow/nitro Patch
@workflow/sveltekit Patch
@workflow/vite Patch
@workflow/vitest Patch
workflow Patch
@workflow/world-testing Patch
@workflow/nuxt Patch
@workflow/ai Patch
@workflow/core Patch
@workflow/web-shared Patch
@workflow/web Patch

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@TooTallNate TooTallNate force-pushed the nr/remove-client-mode branch from aac9033 to cf9fe73 Compare April 10, 2026 17:20
@TooTallNate TooTallNate force-pushed the nr/remove-client-mode branch from a8cd2f8 to 89b944d Compare April 15, 2026 06:17
@TooTallNate TooTallNate changed the base branch from main to nr/preserve-step-fn-names April 15, 2026 06:17
@TooTallNate
refactor(swc-plugin): remove client transform mode, merge into step mode
f977ebf 
Remove the `client` transform mode from the SWC compiler plugin. The
`client` and `step` modes were nearly identical — both preserved step
function bodies, replaced workflow bodies with throw stubs, and emitted
the same JSON manifest. Step mode now absorbs all client-mode behaviors:

- Dead code elimination (previously only workflow + client)
- Hoisted variable references for object property steps
- All integrations use mode: 'step' instead of 'client'

BREAKING CHANGE: The `client` value for the SWC plugin `mode` option is
no longer accepted. Use `step` instead.
@TooTallNate
fix(nitro): force-inline workflow packages in dev mode for serde clas…
ddfe338 
…sId registration

In dev mode, Nitro's Rollup externalizes npm packages like @workflow/core,
so the SWC transform plugin never processes files like run.js. This means
serde classes (e.g. Run) never get the classId registration IIFE, causing
serialization failures when step functions return Run instances.

Uses a Rollup resolveId hook to force workflow SDK packages to be bundled
(non-external) while leaving all other dependencies external. This is more
targeted than noExternals=true which bundles everything and causes TDZ
errors from circular imports in packages like vue-bundle-renderer/h3.

The Nitro module now also ignores .nitro/workflow/** in watchOptions so
writing generated workflow bundles does not retrigger Nitro's own dev
bundle rebuild loop.

Also wraps dev:reload workflow rebuilds and makes LocalBuilder.build()
atomic (writes to temp files, renames on success) to avoid partial output
state during HMR.

For Nuxt, also configures Vite's ssr.noExternal to bundle workflow
packages in the SSR context.
Copilot AI reviewed Apr 16, 2026
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Pull request overview

Removes the SWC plugin’s client transform mode by merging its behavior into step mode, and updates all repository integrations, docs, and fixtures to use the new 3-mode model (Step/Workflow/Detect).

Changes:

  • Dropped Client from TransformMode, updated step mode to include client-mode behaviors (notably DCE + object-property hoisting semantics), and removed client-mode fixture runners/outputs.
  • Updated framework/tooling integrations (Next loader, Rollup, Nest CLI, Builders, CLI) to use mode: 'step' everywhere client was previously used.
  • Updated docs/spec and the SWC playground (WASM + UI/types) to remove the client output/view.

Reviewed changes

Copilot reviewed 103 out of 103 changed files in this pull request and generated 3 comments.

Show a summary per file
File Description
workbench/swc-playground/wasm/src/lib.rs Removes client from batch transform output and runs only workflow+step.
workbench/swc-playground/lib/transform.ts Updates TS types to drop client transform result.
workbench/swc-playground/components/swc-playground.tsx Removes client view/panel/state in the playground UI.
packages/swc-plugin-workflow/transform/src/lib.rs Removes Client mode and folds client behaviors into Step (DCE, hoisting/registration paths, etc.).
packages/swc-plugin-workflow/spec.md Updates specification to reflect 3 modes and step-mode DCE/hoisting behavior.
packages/swc-plugin-workflow/transform/tests/fixture.rs Removes the client-mode fixture test harness.
packages/swc-plugin-workflow/transform/tests/errors.rs Removes the client-mode errors fixture harness and updates imports.
packages/swc-plugin-workflow/transform/tests/fixture/workflow-client-property/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/workflow-arrow-function/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/var-named-step-function/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/using-declaration-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/using-declaration-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/user-named-dunder-default/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/unused-variables-and-types/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/unused-variables-and-types/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/unused-exports/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/unused-exports/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/sync-step/output-step.js Updates step-mode fixture to reflect new object-property hoisting behavior.
packages/swc-plugin-workflow/transform/tests/fixture/sync-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/sync-step-default-export/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/sync-step-class/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/step-with-this-arguments-super/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/step-with-imports/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/step-with-imports/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/step-arrow-function/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/static-method-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/static-method-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/static-getter-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/single-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/single-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/separate-export-statement/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/private-member-dce/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/private-member-dce-native/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/object-property-step/output-step.js Updates step-mode fixture to reflect object-property hoist references.
packages/swc-plugin-workflow/transform/tests/fixture/object-property-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/object-getter-step/output-step.js Updates step-mode fixture to reflect object getter/property behavior.
packages/swc-plugin-workflow/transform/tests/fixture/object-getter-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/nested-steps-in-object-constructor/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/nested-steps-in-object-constructor/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/nested-step-with-closure/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/nested-step-with-closure/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/nested-step-in-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/multiple-const-step-functions/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/module-level-workflow/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/module-level-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/module-level-step/output-step.js Updates step-mode fixture to reflect new DCE behavior.
packages/swc-plugin-workflow/transform/tests/fixture/module-level-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/mixed-functions/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/let-arrow-step-function/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/instance-method-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/instance-method-nested-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/instance-getter-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/factory-with-step-method/output-step.js Updates step-mode fixture to reflect object-property hoist references.
packages/swc-plugin-workflow/transform/tests/fixture/factory-with-step-method/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/expr-fn-default-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/export-default-class-named/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/export-default-class-anonymous/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/export-default-class-anonymous-step-only/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/destructuring/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/default-workflow-collision/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/default-parameter-usage/output-workflow.js Updates fixture to reflect export changes under new behavior.
packages/swc-plugin-workflow/transform/tests/fixture/default-parameter-usage/output-step.js Updates fixture to reflect export changes under new behavior.
packages/swc-plugin-workflow/transform/tests/fixture/default-parameter-usage/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/default-parameter-usage/input.js Updates input fixture to be exported (aligning outputs).
packages/swc-plugin-workflow/transform/tests/fixture/default-arrow-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/deeply-nested-step/output-step.js Updates step-mode fixture to reflect hoisted reference usage.
packages/swc-plugin-workflow/transform/tests/fixture/deeply-nested-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/custom-serialization/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/custom-serialization-require-namespace/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/custom-serialization-require-destructured/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/custom-serialization-local-const/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/custom-serialization-imported/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/closure-typescript-expressions/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/closure-new-expr-and-module-declarations/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/class-expression-binding-name/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/class-expression-binding-name-step-methods/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/anonymous-default-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/agent-with-tool-step/output-step.js Updates step-mode fixture to reflect object-property hoist references.
packages/swc-plugin-workflow/transform/tests/fixture/agent-with-tool-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/fixture/agent-with-tool-step-shorthand-method/output-step.js Updates step-mode fixture to reflect object-property hoist references.
packages/swc-plugin-workflow/transform/tests/fixture/agent-with-tool-step-shorthand-method/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/sync-workflow/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/non-async-functions/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/misspelled-workflow-directive/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/misspelled-step-directive/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/misplaced-module-directive/output-step.js Updates step-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/misplaced-module-directive/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/misplaced-function-directive/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/invalid-exports/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/invalid-default-exports-step/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/instance-methods/output-client.js Deletes client-mode expected output fixture.
packages/swc-plugin-workflow/transform/tests/errors/getter-workflow/output-client.js Deletes client-mode expected output fixture.
packages/next/src/loader.ts Switches all transforms to mode: 'step'.
packages/rollup/src/index.ts Switches Rollup integration transform mode to step.
packages/nest/src/cli.ts Updates generated .swcrc to use mode: 'step' and help text accordingly.
packages/cli/src/commands/transform.ts Removes client from CLI transform modes/options.
packages/builders/src/apply-swc-transform.ts Updates API type to drop client mode.
packages/builders/src/swc-esbuild-plugin.ts Updates SwcPluginOptions.mode type to drop client.
packages/builders/src/base-builder.ts Updates builder SWC plugin usage from client to step.
packages/nuxt/src/module.ts Forces Vite SSR bundling behavior for workflow packages and marks _vite for Nitro.
packages/nitro/src/index.ts Adds dev-only rollup force-inline plugin and dev-time dynamic loading of generated workflow bundles.
packages/nitro/src/builders.ts Writes workflow bundles to temp files first and renames into place.
.changeset/remove-client-mode.md Adds changeset documenting the breaking removal of client mode and migration guidance.

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Comment thread packages/nitro/src/builders.ts Outdated
Comment thread packages/nuxt/src/module.ts Outdated
Comment thread packages/nitro/src/index.ts Outdated
@TooTallNate
fix(nitro,nuxt): address review feedback on dev-mode classId fix
dc6415b 
- nitro builders: use crypto.randomUUID() for temp file suffix instead of
  Date.now() to avoid collisions under rapid/concurrent build() calls,
  and serialize concurrent build() calls through an internal queue so
  two overlapping dev rebuilds cannot clobber each other's temp outputs.

- nitro index: use fileURLToPath() to convert file:// URLs to filesystem
  paths, which correctly handles Windows paths (file:///C:/... -> C:\...)
  and percent-decoding, instead of relying on new URL(...).pathname.

- nuxt module: normalize vite.ssr.noExternal to an array (preserving any
  existing string/RegExp/array entry) before appending workflow package
  matchers, so the force-bundle behavior is not a no-op when noExternal
  is already set to a non-array value.
VaguelySerious
VaguelySerious approved these changes Apr 16, 2026
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LGTM assuming tests pass, we're only landing this on v5 right?

@TooTallNate
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TooTallNate commented Apr 16, 2026

@VaguelySerious correct

@workflow-devkit-release-bot workflow-devkit-release-bot bot mentioned this pull request Apr 16, 2026
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@TooTallNate TooTallNate mentioned this pull request Apr 17, 2026
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@ijjk ijjk ijjk approved these changes

@VaguelySerious VaguelySerious VaguelySerious approved these changes

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@TooTallNate @ijjk @VaguelySerious