Webhook POST from VAPI returns 444 – workflow not triggering

Questions
1

Hi n8n Community,
I’m running into an issue with a webhook on my n8n Cloud instance and I could really use some guidance.
Setup:
n8n Cloud instance: https://simpsonautomations.app.n8n.cloud
Workflow contains a Webhook node with:
Method: POST
Path: RestaurantAIAgent
Response Mode: Immediately
Workflow is active
Right after the Webhook node, I have a Function node that simply returns the payload:
return [{ json: { receivedPayload: $json } }];
Problem:
I’m using VAPI (voice agent) to send POST requests to this webhook.
VAPI logs show:
HTTP method: POST :white_check_mark:
Request status: 444 :cross_mark:
n8n does not show any execution for the workflow.
When I open the webhook URL in a browser, I get:
{“code”:404,“message”:“This webhook is not registered for GET requests. Did you mean to make a POST request?”}
which confirms the webhook exists and is reachable.
What I’ve checked so far:
Workflow is active and saved.
URL is correct, uses HTTPS.
Headers in VAPI include Content-Type: application/json.
JSON payload is valid.
Question:
Why is n8n returning 444 and not triggering the workflow?
Are there any cloud-level firewall/security settings I need to adjust to allow POST requests from VAPI?
Any suggestions on how to properly receive POST requests from external sources like VAPI?
Thanks in advance for any help!

Hi n8n Community,

I’m running into an issue with a webhook on my n8n Cloud instance and I could really use some guidance.

Setup:

  • n8n Cloud instance: https://simpsonautomations.app.n8n.cloud

  • Workflow contains a Webhook node with:

    • Method: POST

    • Path: RestaurantAIAgent

    • Response Mode: Immediately

    • Workflow is active

  • Right after the Webhook node, I have a Function node that simply returns the payload:

return [{ json: { receivedPayload: $json } }];

Problem:

  • I’m using VAPI (voice agent) to send POST requests to this webhook.

  • VAPI logs show:

    • HTTP method: POST :white_check_mark:

    • Request status: 444 :cross_mark:

  • n8n does not show any execution for the workflow.

  • When I open the webhook URL in a browser, I get:

    {"code":404,"message":"This webhook is not registered for GET requests. Did you mean to make a POST request?"}

    which confirms the webhook exists and is reachable.

What I’ve checked so far:

  • Workflow is active and saved.

  • URL is correct, uses HTTPS.

  • Headers in VAPI include Content-Type: application/json.

  • JSON payload is valid.

Question:

  • Why is n8n returning 444 and not triggering the workflow?

  • Are there any cloud-level firewall/security settings I need to adjust to allow POST requests from VAPI?

  • Any suggestions on how to properly receive POST requests from external sources like VAPI?

Thanks in advance for any help!

2

HTTP 444 is a non-standard status code used by some proxies (notably Nginx) to indicate that the server closed the connection without sending a response. This suggests the request may be blocked or dropped before reaching n8n, possibly by a firewall, proxy, or security service (like Cloudflare or a reverse proxy)…

If you are behind a proxy or using Cloudflare, ensure that your proxy settings allow POST requests to reach n8n. You may need to set environment variables like WEBHOOK_URL and N8N_PROXY_HOPS.

Try sending a POST request to the webhook using a tool like Postman or curl with the same headers and payload as VAPI.