[ISSUE] VAPI not using webhook message - Tool Response conflicting with Request Failed Hey everyone, I need help with a specific issue between VAPI and n8n. CONTEXT: I have a tool that checks availability in Google Calendar. The n8n webhook is working and returning the correct response, but VAPI is speaking a different message than what I configured. WHAT'S HAPPENING: 1. Tool Response (data coming from webhook):

json
{
  "success": false,
  "speak": "Sorry. We don't have availability for that day",
  "error": false
}

2. Request Failed configured in VAPI: - Condition:

$.results[0].result.success

Equal

false

- Content:

{{ $.results[0].result.speak }}

3. PROBLEM: Instead of saying "Sorry. We don't have availability for that day", the assistant is speaking a completely different message: "Sorry, Will, we don't have availability for October 14th at 6 PM. Would you like to try another date or time?" WHAT I'VE ALREADY TRIED: - Verify that toolCallId is correct - Confirm that webhook returns HTTP 200 - Validate JSON response - Clear cache and redo tests - Test different condition formats ($.success, $.results[0].result.success) QUESTION: Why is VAPI ignoring the

speak

field from the webhook response and using a message that I didn't configure anywhere? Is there some precedence between Request Failed and the

speak

field of the tool response that I don't know about? SETUP: - VAPI tool connected with n8n webhook - Webhook returns standard structure with toolCallId and result - Request Complete works normally for success: true Has anyone experienced this before? Any help would be appreciated!

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Thanks for the detailed context! To help pinpoint the issue, could you please share the exact JSON response your webhook is returning to VAPI—including the top-level structure? For VAPI to use your custom message, the response must look like:

json
{
  "results": [
    {
      "toolCallId": "your-tool-call-id",
      "result": "Sorry. We don't have availability for that day"
    }
  ]
}

If your webhook response is not wrapped in a

results

array with a

toolCallId

and a single-line

result

, VAPI may ignore it and use a fallback message instead. Can you confirm if your webhook matches this format? Sources: - [Custom Tools Troubleshooting](https://docs.vapi.ai/tools/custom-tools-troubleshooting) - [Custom Tools](https://docs.vapi.ai/tools/custom-tools)

We are reviewing the details of your request and will reach out to you when we have an update or if we need additional information.