88602f5b-97a4-4cec-b6e3-6ea1e5639ec8 For this call-id, I am just using the talk to assistant in Vapi. I am trying to call this assistant and asking it to use a calltransfer tool to transfer to another assistant. The tool seems to say completed successfully, but I get a call.in-progress.error-transfer-failed for the ended-reason, and no call transfer happens. ac204805-117e-4427-949a-0b9d723177d4 This one is a similar case to the above one, except I tried the same scenario in web sdk. Still got the progress.error-transfer-failed for the ended-reason. efea5aff-9143-4cf2-abf1-48c0d35819fe For this call-id, I am using the talk to assistant in Vapi. I tried to add the destination as an assistant name in the calltool, instead of a phone number. But when I clicked on the first assistant (the one that will transfer the user to the destination), it just says that the assistant name in the transfer tool is invalid even though I pasted the correct name. It gives this error in the call log: An error occurred in this call: call.start.error-get-resources-validation. Are there any error logs we could check for this on your end?

Thanks for sharing the call IDs and error details. To clarify, have you already checked the call logs and error messages in the Vapi dashboard or via the [Get Logs API](https://docs.vapi.ai/api-reference/logs/get), or do you need guidance on how to access and interpret these logs for more details on the transfer failures? Source: - [Get Logs API Reference](https://docs.vapi.ai/api-reference/logs/get)

For web calls like

88602f5b-97a4-4cec-b6e3-6ea1e5639ec8

, if you are trying to transfer to a PSTN or SIP number it is not allowed on our platform. You must initiate a call via SIP or PSTN to transfer to either one of those types of phone numbers. Same reason for

ac204805-117e-4427-949a-0b9d723177d4

For assistant to assistant transfers, please use squads. It will allow seamless transfers to any assistant without the need for transfer tools. Just connect the two assistant nodes together and define a handoff criteria.

Did this resolve it? @ArcSiege I'm facing the same issue