Transfer Call - UponAI

Overview

Transfer Call enables your agent to hand off a conversation to a human agent or another destination mid-call.

Add the tool

In your agent’s Functions section, click + Add and select Transfer Call from the dropdown.

Choose a transfer type

Select how the AI should handle the handoff:

Configure the transfer destination

Provide the number or SIP URI to transfer to:

Format	Example
E.164 phone number	`+14158923245`
SIP URI	`sip:username@domain.com`

You can also include optional extensions, or use dynamic variables to set the destination at runtime.

Update your prompt

Tell the agent when to trigger a transfer. Example:

If the caller sounds frustrated or requests a human agent, use the transfer_call tool to route them to a representative.

Direct handoff. The AI agent disconnects immediately after routing the call — no introduction.

The AI agent stays on briefly to detect human presence, deliver a whisper message, and introduce the caller before dropping off.

Setting	Description
On-hold music	Played while connecting
IVR navigation prompts	Navigate menus before reaching a human
Human detection timeout	Default 30 seconds
Auto-greeting	Agent speaks when human answers
Whisper message	Private message delivered to the recipient only
Three-way introduction	Agent introduces caller before dropping off

Caller ID: Show the agent’s number or the original caller’s number (depends on telephony provider support)
Custom SIP headers: Add headers prefixed with X- or labeled User-To-User for routing and metadata