Cold transfer, warm transfer, and conference for telephone calls.
Transfers and conference are agent actions that move a live phone call to a human or another number. The agent runs them as part of an ability, the same way it runs a workflow or knowledge-base lookup. There are three action types: cold_transfer hands the caller off blind, warm_transfer briefs a human supervisor first and then bridges the call, and conference dials another number into the existing room.
These actions run only on the telephone channel. The async text and email engine skips any voice-only action and logs Skipping voice-only action '<type>' on async text channel. Configure them on telephone agents only; they have no effect on chat or email.
Transfers the caller to another number and the agent leaves. No handoff conversation.
You want a fast, unattended handoff (for example, route to a department line).
warm_transfer
Holds the caller, dials a human supervisor, the AI briefs them, then merges both into one call.
A human needs context before taking the caller.
conference
Dials another number into the current room so everyone is on one call.
You want to add a participant without removing the agent.
Add these as actions on an ability. See Abilities and actions for how actions attach to abilities, and Agent assist for live human-in-the-loop monitoring.
The agent places the caller on hold with music, creates a separate supervisor room, dials the human at transfer_number, and briefs them using supervisor_instructions plus the prior conversation. When the supervisor accepts, the agent merges them into the caller’s room (bridge) and resumes audio. If anything fails or the supervisor declines, the caller is taken off hold and the agent speaks the matching message.
caller ──┐ │ on hold + music supervisor room ▼ ┌──────────────┐ [ AI agent ] ── dials supervisor ─► human joins │ │ │ AI briefs them│ │ on accept: merge ◄──────┴──────────────┘ ▼ caller + supervisor bridged in one call
Field
Type
Default
Description
transfer_number
string
required
The supervisor number to dial. Supports template variables.
queue_timeout
int
30
Seconds to wait for the supervisor to join and be connected to the customer.
hold_music_url
string
sample mp3
Hold music file/URL (.wav/.mp3). Falls back to a tone if it cannot be played.
supervisor_instructions
string
see below
How the AI briefs the supervisor before connecting them to the caller.
on_transfer_failed_message
string
see below
Spoken to the caller when the transfer fails.
on_successful_transfer_message
string
see below
Spoken when the supervisor is connected.
on_customer_disconnected_message
string
see below
Spoken to the supervisor when the caller has hung up.
on_supervisor_declined_message
string
see below
Spoken to the caller when the supervisor declines or is unavailable.
condition
string
none
Optional expression; the action runs only when it evaluates true.
