jolly-crimson•2mo ago

Call Transfer is failing

Hey I am trying to forward a call to my indian phone number from the agent over the call and it ended the call i was not transferred but then i tried to get transferred to anohter agent i made in vapi using vapi provide usa number it also failed can you please explain me what is happening!

4 Replies

Vapi Support Bot•2mo ago

To diagnose why your call transfer is failing, first check the endedReason for your call using the Vapi API. Run the following command (replace {call_id} and YOUR_API_KEY):

curl -X GET "https://api.vapi.ai/call/{call_id}" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json"

curl -X GET "https://api.vapi.ai/call/{call_id}" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json"

If the endedReason is not assistant-forwarded-call, review your assistant's configuration—ensure phoneCallProviderBypassEnabled is set to false and remove "phone-call-control" from serverMessages if present. This will help you pinpoint if the issue is with your configuration or the telephony provider.
For more details, see the Debug call forwarding drops guide. Source: - Debug call forwarding drops

⤵️ Mention @Vapi Support Bot for follow-ups 🐥

jolly-crimsonOP•2mo ago

There is no property named as { "phoneCallProviderBypassEnabled": false } @Duckie

Vapi Support Bot•2mo ago

It looks like the phoneCallProviderBypassEnabled property is not a direct setting in the dashboard UI, but is part of the transfer tool's configuration when defined via API or JSON. To ensure your call transfer works, make sure your transfer tool includes the required destination parameter, like this:

"parameters": {
  "type": "object",
  "properties": {
    "destination": {
      "type": "string",
      "enum": ["+1234567890"], // Replace with your target number in E.164 format
      "description": "The destination to transfer the call to."
    }
  },
  "required": ["destination"]
}

"parameters": {
  "type": "object",
  "properties": {
    "destination": {
      "type": "string",
      "enum": ["+1234567890"], // Replace with your target number in E.164 format
      "description": "The destination to transfer the call to."
    }
  },
  "required": ["destination"]
}

Also, remove "phone-call-control" from your assistant's serverMessages if present. This should resolve most transfer issues. For more, see the call forwarding guide. Sources: - Vapi documentation: call forwarding - Debug call forwarding drops

Vapi•5w ago

Hi, could you please provide a call id where you experienced this issue? We would like to review the logs to identify the cause.

Call Transfer is failing

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