Hello, We are stuck trying to implement the dynamic call transfer using VAPI. The call just ends instead of being transfered. When i check the call logs I can see that the call is marked as transferred, but nothing happens. I can also see that the tool is being called correctly with the right destination. I tried multiple destination but same problem.

- Double-check that your server is correctly set up to handle the transfer-destination-request and that it's returning a valid destination payload. - **Webhook**: Ensure that your assistant's server URL is properly set in your assistant settings. - **Responses**: Make sure your server's responses include the correct destination formats and do not miss any required fields. - **Logs**: Review your server and call logs for any error messages or clues as to what might be going wrong. - **Documentation**: Please make sure you've followed all steps outlined in the documentation for dynamic call transfers. If everything seems correctly configured and the issue persists, let me know

Hello, Thank you for your reply:Here is the payload returned by my server: { 'messageResponse': {'destination': {'type': 'number', 'number': '+13.....', 'numberE164CheckEnabled': True, 'message': 'Connecting you to our support line.', 'callerId': '+1....', 'transferPlan': { 'mode': 'warm-transfer-with-summary', 'summaryPlan': { 'enabled': True, 'messages': [ {'role': 'system', 'content': 'Please provide a summary of the call.'}, {'role': 'user', 'content': 'Here is the transcript:\n\n{{transcript}}\n\n'} ] } } } } }

@Yassine I have noticed the warm transfer with summary doesn't always work well. Try using blind-transfer or warm-transfer-wait-for-operator-to-speak-first-and-then-say-message

Your server’s payload looks correctly formatted for a dynamic transfer, but ensure your webhook URL is properly set, your server returns a valid JSON with HTTP 200, and logs show no errors.

Hey guys thanks for the help, I am still enduring some inconsistent call transferring, is there any limitation on international calls from VAPIs side ?

Webhook is not used for transfers?

Yes, Vapi has limitations on international calls, where free numbers can only handle domestic calls, to enable reliable international transfers, you need to import a supported number from providers like Twilio, or Telnyx..

What for?

This allows your server to process the transfer logic and respond with the appropriate destination, such as a phone number or another assistant.

Interesting, so what kind of stuff can you do? All of the transferCall tools I’ve ever added have not included a server url as it seemed vapi handled that. What kind of control do I have with the call if I do that?

Hey Yassine, To help track down this issue, could you share: - The call ID This would really help us figure out what went wrong!