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OpenAI GPT-Live Now Available for Telnyx Voice AI Assistants

30, Sep 2026

OpenAI GPT-Live (openai/gpt-live-1) is now available in Telnyx Voice AI Assistants. GPT-Live is OpenAI's full-duplex speech-to-speech model: it listens and speaks at the same time, so callers can interrupt mid-sentence and the conversation keeps its rhythm. Telnyx provides the phone number, the call, and the tool layer around it.

What's new

  • OpenAI GPT-Live model: Select openai/gpt-live-1 as the model for a Voice AI Assistant in Mission Control.
  • Bring your own OpenAI key: GPT-Live requires your OpenAI API key, added to Telnyx as an integration secret. OpenAI bills the GPT-Live session to your OpenAI account, and your Telnyx call and platform usage stays on your Telnyx account.
  • Speech-to-speech calls: Call audio streams to OpenAI over a WebSocket, so the conversation itself does not pass through separate STT and TTS steps.
  • OpenAI Live voices: The Voice tab lists OpenAI Live voices for GPT-Live assistants, with marin as the default.
  • Delegation for reasoning and tools: GPT-Live handles the conversation and hands reasoning and tool calls to a delegation model. Your assistant's tools, MCP servers, call transfers, and hangups keep working through delegation.
  • Current limits: GPT-Live assistants use OpenAI Live voices only, cannot use a fallback model, and cannot be combined with workflows.
  • Direct SIP option: To run GPT-Live from your own backend instead of a Telnyx assistant, the GPT-Live SIP guide shows how to route a Telnyx number straight to OpenAI over encrypted SIP and control the session from your application.

Why it matters

  • GPT-Live handles turn-taking and barge-in inside the model, so callers can interrupt and talk over the agent without breaking the conversation.
  • GPT-Live cannot call tools on its own. Delegation routes that work through the Telnyx tool stack, so an assistant can look up records, transfer a call, or trigger a webhook mid-conversation.
  • The phone number, call routing, assistant configuration, and tools stay in one Telnyx system, with OpenAI as the model provider on your own key.

Example use cases

  • Inbound support lines where callers talk over the agent and expect it to stop and listen.
  • Appointment booking and scheduling calls that need natural turn-taking.
  • Call flows that pair a fast conversational front end with tool-heavy back-end lookups, such as order status or account changes.

Getting started

  1. Log in to the Telnyx Mission Control Portal.
  2. Add your OpenAI API key as an integration secret.
  3. Navigate to AI → Assistants and create a new assistant or select an existing one.
  4. On the Agent tab, set the model to openai/gpt-live-1 and select your OpenAI API key secret.
  5. On the Voice tab, choose an OpenAI Live voice.
  6. Save the assistant and place a test call.

Learn more in the Voice Assistant quickstart, the OpenAI GPT-Live model page, or the Telnyx GPT-Live SIP guide.