Can't call a step function outside of a workflow if that functions uses dependencies not marked with `"use step"`

[remiconnesson]

The docs mention:

Calling a step from outside a workflow or from another step will essentially run the step in the same process like a normal function (in other words, the use step directive is a no-op). This means you can reuse step functions in other parts of your codebase without needing to duplicate business logic.

Unfortunately it seems that there's a bug that creates "Referrence Error: <non-step dependency> is not defined" when attempting to use any variable or functions not coloured with use-step

A minimal reproduction can be found below:

Minimal reproduction

https://github.com/remiconnesson/useworfklow-rsc-maybe-hoisting-issue-repro

Given those files

Please notice the function below doesnt have "use step" directive

// <file path="utils/dummy-util.ts">
export async function dummyUtil(data: unknown) {
  return data;
}

// <file path="app/workflows/step.ts">
import { dummyUtil } from "@/utils/dummy-util";

// This function succeeds when called in a workflow file but will crash when called outside of a workflow
export async function dummyStep() {
  "use step";
  const data = dummyUtil({ id: crypto.randomUUID() }); // <-- ❌ will crash when the step is called outside of a workflow : `ReferenceError: dummyUtil is not defined`
  console.log(data);
  return data;
}

// <file path="app/workflows/workflow.ts">
import { dummyStep } from "./step";

export async function dummyWorkflow() {
  "use workflow";

  const data = await dummyStep();  // <--  ✅ no issue when used inside a workflow

  return data
}

When called in an API endpoint

// app/api/dummy/route.ts
import { NextResponse } from "next/server";
import { start } from "workflow/api";
import { dummyStep } from "@/app/workflows/step";
import { dummyWorkflow } from "@/app/workflows/workflow";

export async function GET() {
  const run = await start(dummyWorkflow); // <-- This works, and the workflow completes properly ✅
  const runData = await run.returnValue
  console.log("endpoint.1 :", runData)

  const data = await dummyStep(); // <-- this crashes ❌

  return NextResponse.json({
    runData,
    data,
  });
}

we get the following logs on vercel world

2025-12-16 16:17:04.303 [info] endpoint.1:  { id: 'f9dad572-c66a-41f7-a4de-d847791f0f91' }
2025-12-16 16:17:04.309 [error] ReferenceError: dummyUtil is not defined
    at R (.next/server/chunks/[root-of-the-server]__d2b94b46._.js:1:4565)
    at E (.next/server/chunks/[root-of-the-server]__d2b94b46._.js:1:4900)
    at async l (.next/server/chunks/[root-of-the-server]__d2b94b46._.js:1:8109)
    at async d (.next/server/chunks/[root-of-the-server]__d2b94b46._.js:1:9147)
    at async A (.next/server/chunks/[root-of-the-server]__d2b94b46._.js:1:10225)

and the following logs on local world

endpoint.1:  { id: 'c1aca253-0e18-4430-a11e-7468a344862f' }
ReferenceError: dummyUtil is not defined
    at dummyStep (app/workflows/step.ts:3:18)
    at GET (app/api/dummy-endpoint/route.ts:13:31)
  1 | /**__internal_workflows{"steps":{"app/workflows/step.ts":{"dummyStep":{"stepId":"step//app/workflows/step.ts//dummyStep"}}}}*/;
  2 | export async function dummyStep() {
> 3 |     const data = dummyUtil({
    |                  ^
  4 |         id: crypto.randomUUID()
  5 |     });
  6 |     console.log(data);
 GET /api/dummy-endpoint 500 in 1096ms (compile: 8ms, render: 1088ms)