Hi team. I'm using VAPI-MAKE flow with VAPI transient agent created via POST. If you could help me troubleshoot what do I have missing in the flow and why the VM wasn't left by VAPI assistant on this call? Call ID 029572ec-321e-450e-9eea-2086e9916940 The vm prompt was very clear "The person you are trying to reach is not available. Please leave a message after the tone" so I would expect a clear VM to be left by agent. I copied this workflow and previously it was working fine in a similar setup with slightly different Make workflow modules configuration, however I didn't touch any VM or other agent settings that could break VM detection. Thank you for looking into this for me.

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Hello support team. Can I have someone look into this? I believe I posted my query within your working hours window.

For issues related to the agent caller not detecting a clear voicemail (VM) prompt and hanging up, you can try the following troubleshooting steps: 1. Ensure that

assistant.voicemailDetectionEnabled

is set to

false

if you need the bot to interact with automated systems.

json
   {
     "assistant": {
       "voicemailDetectionEnabled": false
     }
   }

2. **Check Call Logs**: Review your call logs to verify if the call ended for reasons like

customer-did-not-answer

. This could help pinpoint if the call was ended due to a voicemail or another issue. For a detailed view of common issues and solutions, refer to the [Call ended reasons documentation](https://docs.vapi.ai/calls/call-ended-reason). 3. **Telephony Provider Logs**: If the problem persists, examine logs from your telephony provider (e.g., Twilio, Vonage) for additional context on call handling and possible errors. For more information on understanding call end reasons and debugging options, you can refer to the [Debug call forwarding drops documentation](https://docs.vapi.ai/phone-calling/transfer-calls/debug-forwarding-drops) and [Debugging voice agents documentation](https://docs.vapi.ai/debugging). These steps should help in diagnosing and resolving the issue with your agent calls.

I have this voicemail detection section used within an assistant prompt "voicemailDetection": { "provider": "vapi", "backoffPlan": { "maxRetries" : 10, "startAtSeconds" : 5, "frequencySeconds": 5 }, "beepMaxAwaitSeconds": 30 }, Do you recommend removing it, and replace it with "voicemailDetectionEnabled": false ?

Hey, sorry it's taking longer than usual our team is looking into and get back to you with an update soon

Thanks Praveen. I did another test with my transient agent setup, and there was the same issue. I still have the same voicemail detection settings in my assistant prompt I posted earlier. Maybe if you could suggest a few directions that I can take to troubleshoot this further. I can share a recording of the call, or some other information if it helps to clarify my case

Yes, replace the

"voicemailDetection"

block with

"voicemailDetectionEnabled": false

to fully disable voicemail detection, unless you still want detection with silent hang-up..

I want assistant to leave a pre-defined VM from "voicemailMessage" in situations like I mentioned initially when there is a clear VM prompt. With "voicemailDetectionEnabled": false and removed voicemailDetection block, can I expect assistant to handle the situation and start leaving "voicemailMessage" correctly (instead of just hanging up the call)?

No with voicemailDetectionEnabled: false and no detection block, the assistant won’t detect voicemail or play voicemailMessage, so you must enable detection for it to work..

Ok, thank you. Now we're getting back to my original request - how can I ensure my transient agent is set to detect VM and leave a voicemailMessage? I posted voicemailDetection block I'm currently using above.

To ensure your transient agent detects voicemail and leaves a message, enable and correctly configure the voicemailDetection block with a supported provider (like Google), set detection timing and retries, and include your predefined voicemailMessage..

What is the difference between using Sessions or Squads compared to what I'm currently using for transient assistant setup, like this ... ? Specifically regarding the voicemail detection issue that I initially reported. { "assistant": { "name": "Outbound call", "model": { "model": "gpt-5-nano", ....

Sessions offer dynamic, real-time call handling, and Squads coordinate multiple assistants for advanced features like voicemail detection, while transient assistants are more static and less flexible, which can limit effective voicemail detection..