Hi, hoping someone can help me out. I’m trying to use a tool to do a call transfer, so i can use the warm transfer plan and the caller id settings from the api documentation. The VAPI call is correctly calling the tool and initiating the transfer to the number i set up, but then disconnects. In twilio it says “Got HTTP 400 response to https://twilio-webhook.aws-us-west-2-backend-production1.vapi.ai/amd?org_id=404fd504-4995-4185-ac93-1ea69bda4ceb&?call_id=965a84a3-18fa-4378-bcba-6220c52a4c19”. My call id is 965a84a3-18fa-4378-bcba-6220c52a4c19. Pls help!!!

@Marketeer Hello! I'm here to assist you. It seems like there might be an issue with the webhook URL or the parameters being passed to it. The error message indicates a 400 HTTP response, which usually means there's a bad request due to incorrect or malformed request data. First, please double-check the webhook URL you have provided to ensure it is correct and adheres to the expected format. Also, make sure that all required parameters are included and properly formatted. If the URL and parameters seem correct, there might be an issue with the server handling the webhook or the data it expects. You may need to review the server logs to identify the exact cause of the 400 error. If you're unable to resolve the issue on your own, please provide more details or reach out to support for further assistance.

@User i have parameters set up for voicemail detection. Is it possible it’s starting to think the transfer is a voicemail and hangs up? Thanks for any help.

@Marketeer yes it is possible and this is how vociemail detection and hangup works you can learn more about it from here https://www.notion.so/vapi/Handling-Voicemail-in-Calls-142008c8393f80f1abb8de8ecb17842d

@Shubham Bajaj that does not at all answer my question. Please see the original thread. Why do my transfers fail every time?

@Marketeer I was reviewing your case and noticed your message. Would you be able to provide me some additional time to resolve this issue for you?

I’m trying to do a warm transfer where the ai gives a summary

@Marketeer I am currently away from the keyboard. I will look into the call ID and debug the issue when I return.

Ok ty

@Marketeer You have to delete your Twilio number from Vapi and your Twilio credentials from Vapi, and then generate them again in the Twilio application because we are getting invalid token logs. If you cannot regenerate your Twilio account credentials, no issue - just add them again after checking and ensuring they are correct. Do let me know how it goes.

Ok I can try that, won’t that reset all numbers I’ve imported? Or can I just do it for that number?

@Marketeer Yeah, it may or may-not reset, but you have to give it a try because in our logs your Twilio credentials are invalid. It is not about number but instead about credentials.

Ok @User , re-added the number. No twilio errors but no transfer either (despite VAPI saying so). Is there something wrong with my api call?

@Marketeer could you share the recent call id?

d6642495-4f65-4dda-aa3e-be3cf13a847e

@Marketeer Remove the server event of type 'phone-call-control' from your assistant. This will allow you to handle the transfer directly instead of through Vapi, which is why it's not working currently. https://cdn.discordapp.com/attachments/1327332001958854727/1328413009055580200/Screenshot_2025-01-13_at_22.46.22.png?ex=67869c86&is=67854b06&hm=934f49e27d8c5f3d52e488d8a0a4b29a63e8678da28cd78e82845d876699885c&

How?