Webhook + RespondToWebhook: “Unused Respond to Webhook node found in the workflow” even when directly connected

[danipiace68]

Hi everyone,
I’m facing a persistent issue with a webhook‑driven workflow on n8n Cloud and would really appreciate an expert eye.
Context
Platform: n8n Cloud
Instance: aitinerary.app.n8n.cloud
Workflow name: “NAVAI – AI Travel Designer (dev)”
Workflow status: Active
Trigger: Webhook node
Method: POST
Authentication: None
Path: 13d37134-a288-4ef3-b215-3650d3e04dd2
Production webhook URL used by my landing page:
https://aitinerary.app.n8n.cloud/webhook/13d37134-a288-4ef3-b215-3650d3e04dd2
The first part of the flow is:
Webhook → Respond to Webhook → Data Preprocessing1 (Code node) → Perplexity Research (HTTP) → …
Problem
Every POST from the landing page returns HTTP 500 and the execution in n8n shows the following error on the Webhook node:
Unused Respond to Webhook node found in the workflow
However:
In the editor canvas the connections are clearly:
Webhook → Respond to Webhook → Data Preprocessing1 → Perplexity Research → …
The exported JSON confirms the same connections:
json
“connections”: {
“Webhook”: {
“main”: [
[
{
“node”: “Respond to Webhook”,
“type”: “main”,
“index”: 0
}
]
]
},
“Respond to Webhook”: {
“main”: [
[
{
“node”: “Data Preprocessing1”,
“type”: “main”,
“index”: 0
}
]
]
},
“Data Preprocessing1”: {
“main”: [
[
{
“node”: “Perplexity Research”,
“type”: “main”,
“index”: 0
}
]
]
}
}
There is only one Respond to Webhook node in the whole workflow.
Node configs (short)
Webhook
Method: POST
Auth: None
Respond: Immediately
Respond to Webhook
Respond with: JSON
Response body (simplified):
javascript
==={{
(() => {
try {
const data = $input.first().json;
return JSON.stringify({
success: true,
message: “Request received. Your itinerary is being generated.”,
customerEmail: data.customerEmail || ‘missing’,
destination: data.destination || ‘missing’,
estimatedTime: “5 minutes”
});
} catch (e) {
return JSON.stringify({
success: false,
message: "Error while building response: " + e.message
});
}
})()
}}
What I already tried
Deleted and recreated the Webhook node from scratch.
Deleted and recreated the Respond to Webhook node from scratch.
Ensured there are no other RespondToWebhook nodes.
Verified that the exported JSON matches what I see in the editor (connections as above).
Updated the frontend to use the production webhook URL (not the test one).
Despite this, each call still fails with 500 and the Webhook node error:
Unused Respond to Webhook node found in the workflow
Question
Given this setup, is there any known edge case or internal constraint that could still cause n8n to consider the Respond to Webhook node “unused”?
Is the pattern Webhook → RespondToWebhook → Code → … fully supported?
Is there anything else I should check (e.g. execution mode, special settings, version issues)?
Would you recommend cloning this workflow into a new one or is this more likely a platform bug?
I’m attaching:
Exported workflow JSON
Screenshot of the editor (showing the connections)
Screenshot of the execution log with the error on the Webhook node
Screenshot of the browser console showing the 500 POST
Any guidance or ideas on what to try next would be hugely appreciated.

[Parintele_Damaskin]

Hey @danipiace68 !

Welcome to n8n community!

Can you share the workflow like this?:

I think your Trigger uses a response mode where the “Respond to Webhook” node is not needed, or you are using it in the wrong place…

Cheers!

[Wouter_Nigrini]

Hi @danipiace68,

You need to change the Webhook Respond property from Immediate to “Respond to Webhook”. Also move your respond node to be the last node called in your workflow as it is useless to respond as the very next step.