Webhook response only after a Wait node

[Multas_Vammo]

Describe the problem/error/question

Hi everyone,

I’m working on integrating Treble with Langflow and I’ve encountered a challenge. Treble requires synchronous transactions, meaning the response from a webhook call must be used immediately to continue the flow. However, Langflow operates asynchronously; it generates a response from the AI and returns it via webhook after a delay.

Here’s a summary of my setup:

• I’m using N8N with a webhook trigger.
• I need to ensure that the response is sent only after Langflow has completed its process and called $execution.resumeUrl to continue the flow.
• However, the “Respond to Webhook” node in N8N is not being triggered as expected, and my request remains pending without a response.

To clarify, the response from the request returns in about 5 seconds, so I don’t believe this is related to a timeout flow of more than 70 seconds.

How do I return the body of the wait webhook on the first webhook?

Has anyone dealt with a similar issue or have any suggestions on how to handle this asynchronous nature with Treble’s synchronous requirements? Any help or advice would be greatly appreciated!

Thank you!

Best

What is the error message (if any)?

Please share your workflow

Information on your n8n setup

• n8n version:
• Database (default: SQLite):
• n8n EXECUTIONS_PROCESS setting (default: own, main):
• Running n8n via (Docker, npm, n8n cloud, desktop app):
• Operating system:

[ihortom]

@Multas_Vammo , according to the screenshot you shared the webhook responded. The problem is not likely to be there. You can experiment with a basic workflow locally setting high Wait period to see that the workflow responds. Something simple like this

Here’s the result I got locally

20:44
~
❯ curl --request POST \
  --url http://localhost:5678/webhook/0084a8eb-5902-4cb4-8c45-074d3521c8e3 \
  --header 'Content-Type: application/json' \
  --data '{
  "q": "Faire la grasse matinée",
  "source": "auto",
  "target": "en",
  "format": "text",
  "alternatives": 0
}'

{"myField":"value"}                                                                                                                                                                                    

20:53
~

I suspect the problem is due to one of the following:

1. Treble expects a response within a certain period of time which is not fulfilled (unlikely as it still wait according to your screenshot)
2. Treble expects a certain response format and keeps waiting for that data structure to be returned but your Respond to Webhook does not return the data in the expected format
3. There are security measure in place that prevent the response to reach (for example, firewall)