Multi-Participant Voice AI Calls Now Available for Telnyx AI Assistants

Telnyx AI Assistants now support multi-participant calls. An assistant can invite another participant into an active call, identify who is speaking at any point, and stay silent when the participants are talking to each other rather than addressing the assistant.

What's new

• Invite tool: The assistant can invite another participant by calling their phone number or SIP URI. When the participant joins, the assistant receives updated conversation context and continues the call with all parties.
• Skip Turn tool: Lets the assistant stay silent intentionally when participants are speaking to each other rather than addressing the assistant. The assistant resumes automatically when someone addresses it.
• Speaker awareness: The assistant identifies who is speaking and who they are addressing throughout the conversation, so it knows when to respond and when to stay out.
• Full tool access during multi-participant calls: After a participant joins, the assistant can still use all configured tools, including calendar integrations, CRM updates, booking APIs, and custom webhooks.

Why it matters

• Assistants previously handled one-to-one calls only. Multi-participant support opens the coordination workflows that make voice AI useful when more than one person is involved: scheduling, handoffs, specialist escalation, and live meeting assistance.
• Skip Turn prevents the assistant from interrupting back-and-forth between participants. Without it, an assistant responds after every turn even when two people are having a side conversation.
• The same tools, instructions, and integrations from one-to-one calls carry over. There is no separate multi-participant configuration surface.

Example use cases

• A scheduling assistant that invites a colleague to a call, stays silent while participants compare availability, then books the meeting when they confirm.
• A customer support assistant that connects a caller to a specialist when the inquiry requires human expertise, then stays on to document the outcome.
• A sales assistant that brings a technical lead into a discovery call when the conversation turns to implementation details.
• A medical coordination assistant that connects a patient and a specialist, manages the introduction, and updates records after the call ends.

Getting started

1. In Mission Control (or through the Assistants API), open your assistant and go to Tools.
2. Add an Invite tool and configure the phone number or SIP URI of each participant the assistant may invite.
3. Add a Skip Turn tool so the assistant can stay silent when participants are talking to each other. Skip Turn does not end the call or disable the assistant: it only tells the assistant not to speak for that turn.
4. Update your assistant instructions to describe when to invite, when to stay silent, and when to resume.
5. Optionally, add participant names to Keyterm Boost on the Voice tab to improve transcription accuracy for those names. Keyterm Boost is supported by the Deepgram Flux and Deepgram Nova-3 transcription models.

Create an assistant with multi-participant tools

curl -X POST https://api.telnyx.com/v2/ai/assistants \
  -H "Authorization: Bearer $TELNYX_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "scheduling-assistant",
    "model": "moonshotai/Kimi-K2.5",
    "instructions": "You are a scheduling assistant. When participants are talking to each other, use Skip Turn and stay silent. Only respond when someone addresses you directly.",
    "tools": [
      {
        "type": "invite",
        "invite": {
          "from": "+19876543210",
          "targets": [
            {
              "to": "+1234567890",
              "name": "Specialist"
            }
          ]
        }
      },
      {
        "type": "skip_turn",
        "skip_turn": {
          "description": "Use this tool when participants are talking to each other and not addressing the assistant."
        }
      }
    ]
  }'

Learn more in the Multi-Participant Calls guide.