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