Hello. Transfer call doesn’t work. I am using the inbuilt tool in the workflow with all basic settings, but as soon as it gets trigger it just hangs up. In the logs it says unknown error at first, then after some time it says call.in-progress.error-capitals-worker-died. I have been trying for 3 days now without any luck. Example call log id 765d1eae-67e6-4e11-b60e-fd25a477a6e5

Thank you for providing the call log ID and error details. Based on the error

call.in-progress.error-capitals-worker-died

, this often points to a configuration issue or a problem with the SIP provider's support for call transfers (such as SIP REFER). Could you confirm if your transferCall tool is configured with the required

destination

parameter and if your SIP provider supports SIP REFER for call transfers? This is a common cause for transfer failures in Vapi. If you are unsure, please check your tool configuration and provider settings, or let me know if you need guidance on how to verify these. Sources: - [Vapi documentation: call forwarding](https://docs.vapi.ai/call-forwarding) - [Vapi documentation: SIP trunking and SIP REFER](https://docs.vapi.ai/advanced/sip/sip-trunk) - [Vapi documentation: call ended reasons](https://docs.vapi.ai/calls/call-ended-reason) - [Vapi Discord: SIP REFER troubleshooting](https://discord.com/channels/1211482211119796234/1343963959421829172)

But I am just using the inbuilt transfer tool with the destination Phone Number, there are no SIP settings to configure?

Looking into it

e44abb5f-2c01-42c3-854b-76792e95e388 Latest log I just tried again

Alright

Just tried again and not working. Is this a platform issue as I can see other posts about this?

We are currently investigating this issue. Thank you for your patience

Thank you!

Seems to be a platform issue. Im not being able to perform assistant to assistant transfers using the transfer call tool.

You are using warm-transfer-say-summary which is only supported for twilio SIP calls and not web calls. Change it to blind-transfer and it should work.

I’ll try again, but I did at first use blind transfer and it didn’t work either.

I see a tool call to "untitled_tool" which is a custom function, but not a transferCall tool. Is there any reason why you opted for a custom function rather than a transferCall tool?

I am trying custom and also inbuilt tool but can’t get either to work.

🟡 02:14:14:599 [twilioStream:cf87a0b7] Couldn't Transfer Twilio Call. Error: The requested resource /2010-04-01/Accounts/AC25dc60bbab3fb3a5affba69645e4ca49/Calls/CA7a6dfb3337346d78e9dbfe6a17486216.json was not found

In the transferPlan, remove the sipVerb line

How do I do that? json code shows as read only ?

Hey Andrej, are you using a different routing system besides the US routing from Twilio?

Yes I am using Twilio Australian routing mate.

Thanks for trying Andrej, can you please make a loom video and show me the complete configuration because it solved the issue for most of the customers.

Will do mate thank you.

Sahil, I am running into the same issue here. Please watch this loom: https://www.loom.com/share/2b7ee8aa87bd47b582203bbaab2b3343 Org Name: Insellerate Workflow: 0d5d8dff-f238-45f4-b27e-c1daeebf9fd2 CallID: 673ff774-ec71-4e1b-b804-1f04617191cd I also have Call Transfer (SIP REFER) enabled in Twilio. I have tried replacing the call node with a function, I've also placed the outbound call via the api. Nothing works. How can we get this fixed? https://cdn.discordapp.com/attachments/1381146102635561060/1384729398669873243/image.png?ex=68537d3f&is=68522bbf&hm=ac04dde041985184a6c40efeccda78812c07812b57c19a430a8c9f56626c6a59&

Sahil, you can just use the Video above as it's pretty much the same problem I have.

Hi Vapi Team, We urgently need your assistance resolving this issue, as it's currently blocking our team from completing a critical project. If we do not receive a response within the next 24 hours, we will need to begin evaluating alternative solutions. As a CRM platform placing millions of call minutes per month, we’re actively seeking a reliable voice agent partner to meet growing client demand. Appreciate your prompt attention.

Call forwarding works just fine in Synthflow, I just tested it. If I can’t get this fixed in Vapi ASAP I will have to move too.

It is a SIP based call.

your schedule is full for another week. I cannot wait that long. how do i need to reconigure to get it working. where are there help articles explaining this? https://cdn.discordapp.com/attachments/1381146102635561060/1385277877867647046/image.png?ex=68557c0f&is=68542a8f&hm=463b77073f721c7a0a2fdd6f923f028c06ee7534591796655af92c547d33457e&

I can't book mate all your time slots are like 3am Sydney time..

Sent you DM.

Still not resolved. Sahil you were offline for the session we agreed on.

huddling you.