How to configure maxDuration for generated /.well-known/workflow/v1/flow route?

[iNishant]

Problem

Getting Vercel Runtime Timeout Error: Task timed out after 60 seconds on /.well-known/workflow/v1/flow.

Environment

• workflow: 4.2.0-beta.71
• Next.js App Router, Vercel Pro, Fluid Compute enabled

What we tried

1. vercel.json functions config:

{
  "fluid": true,
  "functions": {
    "app/.well-known/**/*": { "maxDuration": 780 }
  }
}

2. Also changed the default function timeout to 780s in the Vercel project settings web UI — to rule out the glob pattern not matching.

Neither had any effect — the flow route still times out at 60s.

What is the recommended way to configure maxDuration for the generated internal workflow routes (flow, step, webhook)?

Suggestion

It would be great to have documentation in the Vercel World docs covering recommended options for configuring timeouts on the generated internal workflow functions.

[pranaygp]

If your flow route is running for longer than 60 seconds, it usually means something is wrong since that route is supposed to be extremely quick (it's just a replay of the workflow code to calculate the next state)

Step routes will automatically use the maximum possible maxDuration available on your vercel plan

Could you check your vercel account on the flow route executions to see what's causing it to take so long? If you're struggling to figure it out, please share an example run ID and we can take a look :)

[iNishant]

We are also seeing some OOMs from flow route, could high memory be the issue?

Some run IDs wrun_01KMF5V8FYG476BV5PY0SW87T0, wrun_01KMF5RPQ3P21QG4CBJ6E3XSKQ, wrun_01KMF5HA6DMKKZS2QRKFYRAZ3E

[pranaygp]

@iNishant thanks for sharing. I'll follow up over DMs on X since this is about your deployment on vercel

[NathanColosimo]

@iNishant are you using Bun runtime by any chance? I got OOM on NextJs w/ Bun before and was fixed by moving to Node

[iNishant]

@NathanColosimo yes was using Bun. @pranaygp also suggested trying out Node. Will update if that fixes the issue.