New call termination and voicemail handling controls for AI Assistants

21, Jan 2026

Two new calling configurations give developers tighter control over how AI Assistants end calls and handle voicemail. These settings reduce idle call time, prevent unnecessary minutes, and make outbound call behavior predictable when voicemail answers.

What’s new

User idle timeout: Automatically end calls after a configurable period of caller silence.
Configurable silence threshold: Set the timeout in seconds per assistant.
Voicemail detection support: Enable answering machine detection on outbound calls.
Immediate hangup option: End the call as soon as voicemail is detected.
Leave message and hang up: Play a message, then stop the assistant.
Flexible message type: Use a canned message, a prompted message, or improvisation.

Why it matters

Reduces wasted call minutes caused by prolonged silence.
Prevents assistants from running indefinitely on abandoned calls.
Improves cost control for high-volume outbound calling.
Simplifies voicemail handling logic in client applications.
Aligns assistant behavior with existing call center workflows.

Example use cases

Automatically ending support calls when a caller stops responding.
Outbound notifications that hang up immediately on voicemail.
Appointment reminders that leave a short message, then terminate the call.
Sales or collections workflows that avoid improvising on voicemail.

Getting started

Open Mission Control Portal and select your AI Assistant.
Navigate to the Calling tab.
Set User idle timeout (seconds) to define how long the assistant waits during silence.
Enable voicemail detection and choose an action: hang up, leave a message and hang up, or improvise.
If leaving a message, select a canned message or configure a prompt.
For API workflows, enable answering machine detection on outbound calls and configure voicemail settings in the assistant’s telephony configuration.

Learn more in our developer documentation or contact your Telnyx team.