Voicemail detection plugin / extension similar to Pipecat's VoicemailDetector

[arpanpreneur]

We are running livekit agents in production across thousands of answered calls per day. However 30% of calls are either voicemail or iOS 26 Call Screening bots. This is worsening day by day as people are turning this feature on their phones on.

We need a reliable and repeatable way to implement these features across agents. Generic function calling based approaches just don't work in the real world.

Pipecat has released this VoicemailDetector plugin which uses a parallel LLM processing, to detect and gate voicemail.

https://docs.pipecat.ai/server/utilities/extensions/voicemail https://github.com/pipecat-ai/pipecat/blob/main/src/pipecat/extensions/voicemail/voicemail_detector.py

I would love to see similar implementation for Livekit Agents as well.

Some use cases:

1. Normal voicemail (iOS / non-iOS) - should leave a message and terminate call
2. iOS 26 Call Screening (Truecaller and Google Pixel also bringing this) - Should explain why we are calling but cut the call after a timeout
3. Telecom saying "User has put your call on hold" repeatedly - cut the call after a timeout

Currently I am trying to do a custom implementation by overriding the llm_node to do the detect() and the tts_node to do the gate() functionalities, inspired from the pipecat functionality.