Warm Transfer Acceptance for Voice AI Assistants

Warm Transfer Acceptance is now available for Telnyx Voice AI Assistants. Recipients of a transfer can talk to the assistant and verbally accept or decline the call before the caller is bridged, giving teams control over which calls get through.

What's new

• Verbal acceptance flow: When a transfer starts, the assistant speaks privately with the destination, delivers the handoff context, and asks whether they accept. Only an explicit acceptance bridges the caller.
• Private and shared consult modes: Keep the consult out of conversation history, webhooks, and insights with private mode, or preserve it in the record with shared mode.
• Automatic transfer tool: The complete_transfer tool is added to the assistant automatically when acceptance is enabled. No extra configuration needed.
• Graceful degradation: If the consult cannot be set up, the transfer falls back to a standard warm transfer with recorded message playback.

Why it matters

A standard warm transfer plays a recorded handoff message and bridges the call whether the destination is ready or not. That means dropped calls, transfers to unavailable agents, and frustrated callers left in dead air after a handoff. Warm Transfer Acceptance adds a live consult step so the destination can screen the call, hear the context, and decide whether to take it. The caller stays with the assistant hearing ringback and never hears the exchange. This is call control that normally requires a separate contact center vendor, built into the same platform that runs the assistant.

Example use cases

• Support teams where agents need to review context before accepting a transfer.
• Healthcare scheduling where staff confirm availability before taking a patient call.
• Sales routing where reps screen leads before bridging a prospect.
• Financial services where compliance requires verbal confirmation before connecting a caller.

Getting started

1. In Mission Control, navigate to AI → Assistants and select your assistant.
2. Add or edit a transfer tool with at least one target and set warm_transfer_instructions to your handoff message.
3. Enable warm_transfer_acceptance on the transfer tool by setting enabled to true.
4. Optionally set end_user_target_context_mode to shared to keep the consult in the conversation record.

curl -L 'https://api.telnyx.com/v2/ai/assistants' \n  -H 'Content-Type: application/json' \n  -H 'Authorization: Bearer <TOKEN>' \n  --data-raw '{
    "name": "Support Agent",
    "instructions": "You are a support agent. Transfer calls to the support team when the caller asks for a human.",
    "model": "moonshotai/Kimi-K2.5",
    "tools": [
      {
        "type": "transfer",
        "transfer": {
          "targets": [
            {"name": "Support Team", "to": "+15551234567"}
          ],
          "from": "+15553456789",
          "warm_transfer_instructions": "Briefly summarize why the caller is being transferred and what they already tried. Then ask whether they can take the call.",
          "warm_transfer_acceptance": {
            "enabled": true
          }
        }
      }
    ]
  }'

Learn more in the Warm Transfer Acceptance docs or the Telnyx Voice AI Agents page.