OpenAI Live API lets voice agents place outbound SIP calls
OpenAI made outbound SIP calling available to all organizations through the Live API. A GPT-Live session can dial an E.164 number through a customer's SIP provider while a sideband WebSocket carries call progress, tool events and controls such as DTMF, transfer and hangup.
Why it matters: Voice agents can now initiate phone calls instead of only receiving them, moving telephony, consent, duplicate-event handling and tool execution into the agent's external-action boundary.