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Justin Uberti (@juberti), an OpenAI staffer, posted on 2026-11-05 at 06:01:26 Asia/Shanghai (2026-11-04T22:01:26.000Z) that OpenAI had just promoted the new GPT-Live outbound telephony API to GA. The post says developers can make phone calls from a Live voice agent through any SIP trunk provider—examples named are Telnyx and Twilio—and that calls can use HD Voice and can send and receive keypad events (DTMF). DigIntoAI treats the HD Voice line as Uberti’s staff wording; OpenAI’s Telephony and SIP developer guide does not use that phrase in the outbound section DigIntoAI checked.

Later the same day, Greg Brockman (@gdb) posted at 12:52:32 Asia/Shanghai (2026-11-05T04:52:32.000Z) with the short lead “GPT-Live for outbound telephony:” and quoted Uberti’s GA note. Primary sources for this write-up are Uberti’s post (https://x.com/juberti/status/2118101340186698028), Brockman’s quote (https://x.com/gdb/status/2118204795219489172), and OpenAI’s Place an outbound call guide (https://developers.openai.com/api/docs/guides/voice-sip#place-an-outbound-call). OpenAI’s docs and staff posts are self-reported; DigIntoAI hasn’t tested outbound calling—no SIP trunk was wired up here, and DigIntoAI has not placed a live outbound call.

Related DigIntoAI notes: OpenAI Custom Voices—Prompt Design vs Recording Clone, and Where Each Works, OpenAI Decisions API Is Generally Available with GPT-6 Luna, Why Agents API Scheduled Automations Show Completed Before Work Finishes, and Cat Wu Joins OpenAI to Lead Core Products Product Management.

What GA means on the Live path

OpenAI’s developer docs draw a sharp product boundary. The outbound guide states, verbatim: “Outbound SIP calling is available to all organizations through the Live API, not the Realtime API call-creation endpoint.” That line sets the product boundary. The GA claim is about GPT-Live／Live API outbound SIP—not a claim that Realtime call-creation itself just went GA.

In the Live flow, placing a call uses Create session: POST /v1/live/sessions with transport.type: "sip". The docs’ example model is gpt-live-1. Outbound dialing does not need an incoming-call webhook or an accept step—Create session starts the dial. A sideband WebSocket attach listens for call progress such as transport.ringing, transport.answered, and transport.failed. SIP still carries the audio; the sideband carries events and controls.

Inbound SIP and Realtime telephony docs remain on the same voice-sip page for other flows. Inbound／Realtime materials are still there, but this GA is Live outbound—not Realtime call-creation GA.

“All organizations” means organizations that can use the Live API path as documented. DigIntoAI does not read that as free unlimited calling for every person, and does not add price, quota, or region limits—the outbound section DigIntoAI used does not spell those out.

SIP trunk, DTMF, and duration caps

Trunk setup in the guide expects TLS signaling (sips:) plus SDES-SRTP media. Per-request fields include provider_url, digest auth, caller_number, and an E.164 destination. SIP URI destinations are not supported—the destination must be a phone number in E.164 form.

Bidirectional DTMF is documented on the active-call controls: the sideband receives transport.dtmf.received when a key is pressed, and sending uses transport.dtmf.send, followed by transport.dtmf.sent when the tone goes out.

Duration limits are explicit and not configurable in the creation request: ringing is limited to 3 minutes, and a connected call is limited to 2 hours. DigIntoAI has not measured those caps on a live trunk.

Uberti’s GA post is also where DigIntoAI anchors HD Voice and the “any SIP trunk provider” examples (Telnyx／Twilio). That attribution stays with the staff post—not as a quote from the voice-sip guide’s outbound section.

DigIntoAI status

DigIntoAI has not configured a SIP trunk against GPT-Live, has not completed an outbound place-call, and has not verified HD Voice audio quality, DTMF round-trips, or the 3-minute／2-hour caps in practice. Everything above follows OpenAI’s developer docs and the two staff posts as self-reported.

Quick facts

  1. Who. Justin Uberti (@juberti) GA post; Greg Brockman (@gdb) quote; OpenAI developer docs (Place an outbound call).
  2. When. Uberti 2026-11-05 06:01:26 Asia/Shanghai; Brockman 2026-11-05 12:52:32 Asia/Shanghai.
  3. What. GPT-Live outbound telephony API promoted to GA.
  4. Trunks. Any SIP trunk provider; Telnyx and Twilio named as examples (Uberti).
  5. HD Voice. Stated in Uberti’s post—not treated as a voice-sip docs quote.
  6. DTMF. Send and receive keypad events (Uberti + docs sideband events).
  7. API boundary. Available to all organizations through the Live API, not the Realtime API call-creation endpoint (docs).
  8. Session. POST /v1/live/sessions, transport.type: "sip"; example model gpt-live-1; no inbound webhook／accept for outbound.
  9. Media／signaling. TLS (sips:) + SDES-SRTP; E.164 destination; SIP URI destination unsupported.
  10. Limits. Ringing ≤3 minutes; connected ≤2 hours; not set in the create request.
  11. Not tested. DigIntoAI hasn’t tested outbound calling.
  12. Not invented here. Free unlimited calling; price／quota／region rules the outbound section does not spell out.

In short

OpenAI staff marked GPT-Live outbound telephony as GA on 2026-11-05 (Asia/Shanghai), with Brockman amplifying Uberti’s note. Developers can dial out from a Live voice agent over SIP trunks such as Telnyx or Twilio; Uberti also cites HD Voice and bidirectional DTMF. Official docs put the capability on the Live API for all organizations, explicitly not the Realtime API call-creation endpoint, with ringing capped at about 3 minutes and connected calls at about 2 hours. DigIntoAI hasn’t tested outbound calling—OpenAI’s docs and staff posts only.

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