GPT-Live handles a spoken conversation while a backend agent looks up information, uses tools, and completes tasks. It can listen while speaking, a capability called full duplex. Sending work to the backend is called delegation: the conversation can continue while that work runs.
For example, a user can ask about an order, add a detail while the backend checks its status, and hear the result when it is ready. You choose the backend model or agent independently of the voice model; Realtime uses one model for speech, reasoning, and tool selection.
Understand the two parts
- GPT-Live handles conversation. It listens, speaks, and decides when to ask the backend for help. Give it a short prompt for conversation style and when to delegate.
- The backend handles delegated tasks. With Responses delegation, use a supported Responses model. With client delegation, connect any model, agent harness, or service your application runs. The backend reasons, uses tools, and returns results for GPT-Live to communicate. Keep detailed instructions, business rules, and tool workflows here.
Your application owns permissions, confirmations, private function execution, and durable task state. Interrupting speech does not automatically cancel backend work. See Voice agents to compare GPT-Live with Realtime and chained voice applications.
Choose how to run the backend
Start with Responses delegation when a managed backend fits: GPT-Live calls your configured Responses model, supplies conversation context, and returns results. Choose client delegation when your application needs to control backend execution, context, or which results reach GPT-Live.
See Choose a delegation mode for the comparison and configuration details. Choose the mode when you create the session; to change modes, start a new session.
Connect your first session
Start with the GPT-Live WebRTC quickstart. Its browser and server example connects microphone input and speaker output, with a Responses backend that can search the web.
You need a microphone, a browser page served over HTTPS or localhost, and a trusted server with an OpenAI project API key. Keep the key on the server.
- Write a short conversation prompt that tells GPT-Live when to ask the backend for help.
- Follow the quickstart to connect the browser’s microphone, audio playback, and event channel. Your server creates the session and exchanges the browser’s connection offer for an answer.
- Wait for
session.started, then speak and listen to a reply. Ask a question that needs current information to try the web search backend. - End the conversation and close the session to collect final usage and release the connection.
Check both the spoken conversation and the backend result. A session-start event confirms startup; listening to a reply and checking the search result verify separate parts of the application.
GPT-Live voice sessions are billed by duration, per second. See the model pricing for the current rate. Backend model and tool usage is billed separately. See Cost optimization for usage accounting and ways to reduce costs.
Choose a connection
- WebRTC for browser voice applications. Media tracks carry audio; a data channel carries JSON events.
- WebSockets for server-side audio integrations. The primary socket carries audio and control events.
- Server-side controls for backend access to an existing session. A sideband connection carries events while audio stays on the primary connection.
- Telephony and SIP for phone integration paths and provider guidance.
Partner integrations
For applications built with LiveKit, Twilio, Telnyx, or Daily/Pipecat, start with the partner integration overview to choose a connection for your existing media path.
Continue building
- Shape conversation style and delegation behavior in Prompting GPT-Live.
- Connect tools and reduce backend latency in Delegation and tools.
- Manage context, transcripts, and session lifecycle in Managing sessions.
- Choose a migration path for your Realtime or text-based agent in Migrate to GPT-Live.
- Test conversation and task outcomes in Evaluating voice agents.