URGENT Hey Vapi Team- I am seeing transfers fail on inbound calls Summary: Goal: When user says it's an emergency, assistant triggers ⁨⁨⁨`transferCall`⁩⁩⁩ tool and the call should bridge to a phone number. Actual: Call ends immediately (no transfer). Custom LLM response (what my system returns): { "function_call": { "name": "transferCall", "arguments": { "destination": { "type": "number", "number": "+90XXXXXXXXXX" } } } } Call details: Call ID: 019c151f-c58e-7bb7-a0a5-6ed934b8506d Timestamp: 31 Jan 8:35 PM (GMT+3, Istanbul) End reason shown: Assistant forwarded the call I did NOT see transfer-update in the call logs and even thought the end reason is assistant transferred the call the phone call ended so there were no transfers happened. Question: Is there any known issue/config requirement for transferCall in custom LLM flows? Can you check why this call ends instead of transferring? Thanks!

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Check your assistant configuration for the following: Make sure

phoneCallProviderBypassEnabled

is set to

false

and remove

"phone-call-control"

from your

serverMessages

array unless you are handling transfers manually. Here’s an example of the correct config:

json
{
  "assistant": {
    "serverMessages": ["status-update"]
  },
  "phoneCallProviderBypassEnabled": false
}

Update your config and test again—this resolves most transferCall issues in custom LLM flows ([see documentation](https://docs.vapi.ai/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops)). Source: - [Debug call forwarding drops](https://docs.vapi.ai/phone-calling/in-call-control/transfer-calls/debug-forwarding-drops)

I cannot directly edit the json file in vapi dashboard. I've checked and serverMessages does not contain phone-call-control but I could not check phoneCallProviderBypassEnabled. where can I find it and how can I change the config?

I'm also facing the same issue 😭

I see why the call ends instead of transferring no transfer-update in logs usually means the transferCall isn’t reaching the phone provider, often due to missing phone-call-control in serverMessages or phoneCallProviderBypassEnabled being off. Can you check if that flag is enabled for this flow? Also, are there any limitations on LLM-triggered outbound transfers in your current setup? @OzZy

in the latests logs I've gotten the transferCall was succesfull but the the other phone did not ring and call ended. https://cdn.discordapp.com/attachments/1467629691962917118/1467907991691989226/image.png?ex=69821759&is=6980c5d9&hm=1ba7d467f9a7e74ea290b04112a0e98b6d196222d6b2f9d427106f0a9d17c59b&

please send that call id and we'll check the logs @OzZy

019c1e75-3d85-7ff3-8831-d432922fb3ec