migrating-to-workflow-sdk

name	migrating-to-workflow-sdk
description	Migrates Temporal, Inngest, Trigger.dev, and AWS Step Functions workflows to the Workflow SDK. Use when porting Activities, Workers, Signals, step.run(), step.waitForEvent(), Trigger.dev tasks / wait.forToken / triggerAndWait, ASL JSON state machines, Task/Choice/Wait/Parallel states, task tokens, or child workflows.
metadata	{"author":"Vercel Inc.","version":"0.2.0"}

Migrating to the Workflow SDK

Use this skill when converting an existing orchestration system to the Workflow SDK.

Intake

1. Identify the source system:
   • Temporal
   • Inngest
   • Trigger.dev
   • AWS Step Functions
2. Identify the target runtime:
   • Managed hosting -> keep examples focused on start(), getRun(), hooks/webhooks, and route handlers.
   • Self-hosted -> also read references/runtime-targets.md and explicitly say the workflow/step code can stay the same, but deployment still needs a World implementation and startup bootstrap.
3. Extract the source constructs:
   • entrypoint
   • waits / timers
   • external callbacks / approvals
   • retries / failure handling
   • child workflows / fan-out
   • progress streaming
   • external side effects

Default migration rules

• Put orchestration in "use workflow" functions.
• Put side effects, SDK calls, DB calls, HTTP calls, and stream I/O in "use step" functions.
• Use sleep() only in workflow context.
• For Signals, step.waitForEvent(), and .waitForTaskToken, choose exactly one resume surface:
  • resume/internal -> createHook() + resumeHook() when the app resumes from server-side code with a deterministic business token.
  • resume/url/default -> createWebhook() when the external system needs a generated callback URL and the default 202 Accepted response is fine.
  • resume/url/manual -> createWebhook({ respondWith: 'manual' }) only when the prompt explicitly requires a custom response body, status, or headers.
  • If a callback-URL prompt does not specify response semantics, default to resume/url/default and make the assumption explicit in ## Open Questions.
• Never pair createWebhook() with resumeHook(), and never pass token: to createWebhook().
• Wrap start() and getRun() inside "use step" functions for child runs.
• Use getStepMetadata().stepId as the idempotency key for external writes.
• Use getWritable() in workflow context to obtain the stream, but interact with it (write, close) only inside "use step" functions.
• Prefer rollback stacks for multi-step compensation.
• Choose app-boundary syntax in this order:
  1. If the prompt explicitly asks for framework-agnostic app-boundary code, use plain Request / Response even when a framework like Hono is named.
  2. Otherwise, if the target framework is named, shape app-boundary examples to that framework.
  3. Otherwise, keep examples framework-agnostic with Request / Response. Do not default to Next.js-only route signatures unless Next.js is explicitly named.

Fast memory aid:

• Callback URL + default ack -> createWebhook()
• Callback URL + custom ack -> createWebhook({ respondWith: 'manual' })
• Deterministic server-side resume -> createHook() + resumeHook()

Fast-path router

Load references/resume-routing.md when the source pauses for Signals, step.waitForEvent(), or .waitForTaskToken.

Fast defaults:

• callback URL only -> resume/url/default
• callback URL + explicit custom response -> resume/url/manual
• deterministic server-side resume -> resume/internal
• self-hosted -> add runtime/self-hosted
• named framework -> add boundary/named-framework
• explicit framework-agnostic request -> add boundary/framework-agnostic

Before drafting ## Migrated Code, write the selected route keys in ## Migration Plan.

Source references

• Temporal -> references/temporal.md
• Inngest -> references/inngest.md
• Trigger.dev -> references/trigger-dev.md
• AWS Step Functions -> references/aws-step-functions.md

Shared references

• references/shared-patterns.md — reusable code templates for hooks, child workflows, idempotency, streaming, and rollback.
• references/runtime-targets.md — Managed vs custom World guidance.
• references/resume-routing.md — route-key selection, obligations, and exact ## Migration Plan shape.
• references/retries.md — canonical retry mechanics: stepFn.maxRetries, RetryableError({ retryAfter }), FatalError.

Required output shape

Return the migration in this structure:

## Migration Plan
## Source -> Target Mapping
## Migrated Code
## App Boundary / Resume Endpoints
## Verification Checklist
## Open Questions

Verification checklist

Fail the draft if any of these are true:

• ## Migration Plan omits Route keys
• ## Migration Plan omits Why these route keys
• ## Migration Plan lists route keys that do not match the prompt
• ## Migration Plan lists required code obligations that do not match the selected route keys
• Source-framework primitives remain in the migrated code
• Side effects remain in workflow context
• sleep() appears inside a step
• Stream interaction (getWriter(), write(), close()) appears inside a workflow function
• Child workflows call start() / getRun() directly from workflow context
• External writes omit idempotency keys
• Hooks/webhooks are missing where the source used signals, waitForEvent, or task tokens
• A callback-URL flow uses createHook() + resumeHook() instead of createWebhook()
• A resume/url/default or resume/url/manual migration invents a user-authored callback route or resumeWebhook() wrapper when webhook.url should be the only resume surface
• createWebhook() is given a custom token or paired with resumeHook()

Validation note:

• Reading webhook request data in workflow context is allowed. Only request.respondWith() is step-only.

Additional fail conditions:

• resume/internal output omits resumeHook() in app-boundary code
• resume/internal output omits a deterministic business token
• resume/internal output emits createWebhook() or webhook.url
• resume/url/default output does not pass webhook.url to the external system
• resume/url/default output emits resumeHook(), respondWith: 'manual', or RequestWithResponse without a custom-response requirement in the prompt
• resume/url/default output invents a user-authored callback route or resumeWebhook() wrapper when webhook.url is the intended resume surface
• resume/url/manual output does not pass webhook.url to the external system
• resume/url/manual output omits RequestWithResponse or await request.respondWith(...)
• resume/url/manual output calls request.respondWith(...) outside a "use step" function
• resume/url/manual output invents a user-authored callback route or resumeWebhook() wrapper when webhook.url is the intended resume surface
• createWebhook() is paired with resumeHook()
• self-hosted output omits World extends Queue, Streamer, Storage, startWorkflowWorld(), or the explicit note that the workflow and step code can stay the same while the app still needs a custom World
• named-framework output mixes framework syntax with plain Request / Response app-boundary code without a framework-agnostic override

For concrete passing code, load:

• references/shared-patterns.md -> ## Generated callback URL (default response)
• references/shared-patterns.md -> ## Generated callback URL (manual response)
• references/runtime-targets.md -> ## Self-hosted output block
• references/aws-step-functions.md -> ## Combined recipe: callback URL on self-hosted Hono

Sample prompt

Migrate this Inngest workflow to the Workflow SDK.
It uses step.waitForEvent() with a timeout and step.realtime.publish().

Expected response shape:

## Migration Plan
## Source -> Target Mapping
## Migrated Code
## App Boundary / Resume Endpoints
## Verification Checklist
## Open Questions

Example references

Load a worked example only when the prompt needs concrete code:

• references/shared-patterns.md -> ## Named-framework internal resume example (Hono)
• references/shared-patterns.md -> ## Generated callback URL (default response)
• references/shared-patterns.md -> ## Generated callback URL (manual response)
• references/runtime-targets.md -> ## Self-hosted output block
• references/aws-step-functions.md -> ## Combined recipe: callback URL on self-hosted Hono

Reject these counterexamples:

• resume/url/default or resume/url/manual + user-authored callback route when webhook.url is the intended resume surface
• createWebhook() paired with resumeHook()
• named-framework app-boundary output mixed with plain Request / Response without a framework-agnostic override