Step functions not found when using Turbopack dev mode with non-local world backends

[jcourson-bg]

Bug Report

Description

When running a Next.js app in Turbopack dev mode with a non-local world backend (e.g. postgres via Graphile Worker), step functions fail with:

Step "step//./workflows/chat/steps/load-context//loadChatContext" not found

Root Causes

The generated step route (app/.well-known/workflow/v1/step/route.js) calls registerStepFunction for each step, but Turbopack only compiles it on HTTP request for dev. The postgres world invokes steps in-process via Graphile Worker, so the route never loads and the registry stays empty.

registeredSteps in private.ts is a plain Map(). If Turbopack creates duplicate module instances, registerStepFunction and getStepFunction use different Maps. world.ts already avoids this with globalThis[Symbol.for(...)].

Fix

Use globalThis + Symbol.for for the step registry and document that non-local worlds need to import the step route in instrumentation.ts:

if (process.env.NEXT_RUNTIME !== "edge") {
  const { getWorld } = await import("workflow/runtime");
  await getWorld().start?.();
  await import("./app/.well-known/workflow/v1/step/route.js");
}