Hello, I am using the warm transfer tool function and no message is played to the receiving agent - it just connects the calls. Is this a setup or known issue?

Hi there! 👋 I understand you're having an issue with the warm transfer tool function not playing any message to the receiving agent. While I can't determine if this is specifically a setup issue in your case without more details, I can definitely help with some common causes and solutions for this problem. Based on the information I've found, there are several known issues and configuration options that could explain why your warm transfer isn't playing a message: ## Common Causes & Solutions ### 1. Transfer Mode Configuration Make sure you're using the correct warm transfer mode. According to the [Vapi documentation](https://docs.vapi.ai/call-forwarding), you need to add a

transferPlan

object to your

transferCall

tool with the appropriate mode:

json
"transferPlan": {
  "mode": "warm-transfer-with-message",
  "message": "Hey, this call has been forwarded through Vapi."
}

### 2. Request-Start Message Interference The

request-start

message might be interfering with your custom message. Try setting it to an empty string:

json
"messages": [
  {
    "type": "request-start",
    "content": "",
    "contents": [],
    "conditions": []
  }
]

### 3. Message Timing Issues If the warm message starts too early (before the receiving agent answers), use the

warm-transfer-wait-for-operator-to-speak-first-and-then-say-message

setting, which delays the message until after the operator speaks. ### 4. Ensure Text Content is Voiced First A property named

isPrecededByText

can ensure that text content is voiced before the tool call is executed. This might help if the message and transfer are happening too close together. ### 5. Model Configuration Try setting the model to "gpt-4o/gpt-4o-mini" and adjusting the temperature to 0.3, as this has resolved similar issues for other users. ### 6. Check for Empty Message Field An empty message field in the transfer tool configuration will result in a silent transfer. Make sure your message field contains text.

Hey! To help track down this issue, could you share: - The call ID - What response you expected to get - What response you actually got instead This would really help us figure out what went wrong!