Call control transfer call just ends the call.
# support
m
Here's the call id: f819487f-976c-4fa8-bed2-13825b6c99ef. I get a response {"status":"ok"} from the call control endpoint but the call just ends.
Here's what my request body looks like: { "type": "transfer", "destination": { "type": "number", "number": "+13108972043", }, "content": "Transferring your call now" }
v
Hi there! I understand you're experiencing an issue where your call control transfer call is ending unexpectedly, despite receiving a "status: ok" response from the endpoint. While I can't determine the exact cause for your specific call ID without examining the detailed logs, I can definitely help with some common causes and troubleshooting steps for this issue. This is a known issue that several users have reported. Here are some potential causes and solutions: 1. **Server Event Conflict**: If you have enabled the "phone-call-control" server event, this could be causing the issue. According to [user reports](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1330092161835733013), this event allows you to handle call transfers instead of Vapi, which can cause calls to be marked as forwarded but actually end. Try removing this server event from your assistant. 2. **Twilio Routing Issues**: Some users have resolved similar issues by [changing the routing to U.S. in Twilio](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337685081287954546), especially if you're in a different region. 3. **SIP Configuration**: Ensure your system is configured to handle SIP REFER messages, which are [often required for transferring calls](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1333634755044048979). 4. **Web Call Limitations**: If you're using web calls, note that [phone call transfers on web calls are not supported](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337162299621900359) and will result in the call hanging up. Try using phone calls instead. 5. **Destination Format**: Make sure your forwarding phone number is in the correct E.164 format (e.g., +15558675309) and that you're providing a valid destination to the transferCall tool.
6. **Model Configuration**: Try [setting your model temperature to 0.3](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1341953566801264690) and reworking your prompt using the Vapi prompting guide for tools calling. Would you be able to share more details about your setup, such as whether you're using web calls, Twilio, or if you have the "phone-call-control" server event enabled? Sources: - [Discord Thread about phone-call-control server event](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1330092161835733013) - [Discord Thread about Twilio routing](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337685081287954546) - [Discord Thread about SIP REFER messages](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1333634755044048979) - [Discord Thread about web call limitations](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1337162299621900359) - [Discord Thread about model temperature](https://discord.com/channels/1211482211119796234/1211483291191083018/threads/1341953566801264690)
m
We're using twilio for this agent
Disabling the phone-call-control server event worked!
FYI, the sources links in the response don't work for me. It would be better if you linked out to actual web pages. Links to discord are very hit or miss.
You can mark this as resolved
k
Marking this ticket as Solved ✅