Outbound calling generally available to developers
OpenAI on Nov. 4 (Nov. 5 Japan time) made the ability to place phone calls from its voice AI "GPT-Live" generally available (GA) in its developer API. Realtime AI lead Justin Uberti announced it on X, and President Greg Brockman quoted and shared the post. Companies can place calls from their own voice agents to real phone numbers.
The official documentation states that outbound calling is available to all organizations through the Live API. The call-creation feature of the earlier voice API, the "Realtime API," is not covered. The documentation does not use the term "general availability"; that wording comes from the announcement post and news reports.
GPT-Live is a voice model that can speak while listening, which OpenAI added to ChatGPT in July and released in its API on Sept. 10 (Sept. 11 Japan time). In September, the developer site Prompt Blueprints reported that the API returned an error if outbound calling had not been enabled for an organization.
- GPT-Live released in ChatGPTOfficial
- GPT-Live-1 released in the APIOfficial
- Report says outbound calling must be enabled per organizationReport
- Telnyx's voice agent service adds supportOfficial
- General availability of outbound calling announcedOfficial
Supports button presses and transfers
To place a call, the developer passes the phone number and details of the carrier they contract with when creating a session. The official documentation explains that the carrier handles the connection to the phone network, and GPT-Live handles the conversation. Destinations use phone numbers in a format that includes the country code.
The signals generated when phone buttons are pressed (DTMF) are supported for both sending and receiving. According to Crypto Briefing, agents can navigate companies' automated phone menus. Call transfer and hang-up features are also available, and developers can receive ringing, answered and failed statuses.
Ringing is limited to 3 minutes and connected calls to 2 hours, and these limits cannot be changed.
Conditions on connecting "any line"
The announcement said calls could be placed over any line (SIP trunk), such as Telnyx or Twilio. According to the official documentation, the line must support encrypted connections (TLS and SDES-SRTP). Local host names and internal IP addresses are rejected.
In OpenAI's list of partners, Twilio handles inbound and outbound calls and Telnyx handles outbound calls. Bandwidth handles inbound calls only. India's Ozonetel, which Crypto Briefing listed as supported, is not on the list.
Support for high-quality calls (HD Voice) is also part of the announcement, but OpenAI's documentation does not use the term, stating only that the audio format is determined when the SIP connection is made. Telnyx, in its own guide to handling 16kHz audio, explains that wideband audio is not guaranteed on every call. If any segment along the way uses conventional audio quality, the call will not be high quality. This guide covers steps that use Telnyx's media streaming feature, which is a different path from a direct SIP connection.
Audio costs $0.05 a minute; carrier charges are separate
Audio pricing for GPT-Live 1 is $0.05 per minute, billed by the second. It is time-based billing that does not separate input and output, so a 10-minute call costs $0.50 for audio. If other models or features are called behind the scenes, their standard charges are added.
Whether there are charges specific to outbound calls could not be confirmed, as the official documentation does not mention them. Crypto Briefing reported that carrier charges apply in addition to API fees. On Telnyx's price list, SIP outbound calls to the United States start at $0.005 per minute.
The per-minute audio price is $0.03 cheaper than the $0.08 for SpaceXAI's (formerly xAI) "Grok Voice 3.0" and ElevenLabs' "Eleven Realtime v1." However, what is included differs by company: ElevenLabs adds language model token charges on top, and Grok Voice charges $0.004 per text input. OpenAI's separate "gpt-realtime-2.1" line uses token billing at $32 for audio input and $64 for output per 1 million tokens.
Regions covered and regulatory compliance unconfirmed
The official documentation as of Nov. 5 does not list the countries or regions that can be called. A description of connection endpoints for Europe appears only in the section on inbound calls. The documentation also does not address consent from the person being called or identifying the caller as an AI. ORIENS could not open OpenAI's terms of use and was unable to confirm how outbound calls are treated.
Partners place responsibility for legal compliance on developers. Twilio cautions that outbound calls must follow local rules, and Telnyx asks developers to check requirements on consent, calling hours, AI disclosure, recording and automated dialing.
In February 2024, the U.S. Federal Communications Commission (FCC) ruled that an existing telephone consumer protection law applies to automated calls using AI-generated voices. According to a law firm's analysis, callers must obtain the prior express consent of the person called, and written consent is required for telemarketing calls. OpenAI's official documentation does not indicate how it addresses this ruling.
Consumer calling-on-your-behalf services also emerge
On the same day, Nov. 4, the official account of SpaceXAI's AI agent "Grok Bot" announced a feature that places calls on behalf of users. Grok Bot is a feature requested by general users; according to Teslarati, its terms require it to identify itself as an assistant acting for the user, and it can currently call only U.S. numbers. GPT-Live's outbound calling is a component companies build into their own products, and OpenAI's documentation does not set rules on self-identification or call destinations.
Google's "Duplex" and Meta's "Muse" can also place phone calls. Among models for voice agents, ElevenLabs released Eleven Realtime v1 in October. On Nov. 3 (Nov. 4 Japan time), unannounced names that may be voice models briefly appeared in OpenAI's API, and their relationship to GPT-Live is unknown.
Partner Twilio highlights demand for voice AI
Partner Twilio's July-September quarter results, announced on Oct. 29 (Oct. 30 Japan time), showed revenue up 20% from a year earlier to $1.56 billion. Growth on what the company calls an organic basis was 16%, and it forecast October-December quarter revenue of $1.595 billion to $1.605 billion, up 11% to 12% organically.
According to AI Weekly, the earnings materials cited customer wins with AI companies such as ElevenLabs, and the shares fell more than 15% in after-hours trading on a cautious outlook. The impact of OpenAI's outbound calling on carriers' revenue is not clear.
