OpenAI Puts GPT-Live-1 in the API at $0.05/Min: 30-Point Benchmark Jump, #1 on Tau3
OpenAI launched GPT-Live-1 in the developer API on Wednesday, priced at $0.05 per minute for the voice layer. The model was introduced in ChatGPT in July but is now available for third-party developers to pair with any backend model or tool harness.
GPT-Live-1 is a full-duplex system: it listens and speaks at the same time rather than operating on a turn-based model. The design change targets a class of conversational bugs — interruption handling, backchannelling, response timing — that prior voice APIs addressed imperfectly.
Benchmark Numbers
OpenAI’s release measured GPT-Live-1 against GPT-Realtime-2.1 on Full Duplex Bench, the standard evaluation for bidirectional voice systems. GPT-Live-1 improves the score by 30 percentage points, with the gains concentrated in two areas: turn-taking latency and interactive behaviour. Those are the dimensions Full Duplex Bench specifically penalises prior architectures on.
On Tau3 — which measures end-to-end voice-agent performance on real tasks rather than individual turn quality — GPT-Live-1 paired with GPT-6 Astra at medium reasoning effort ranks first across tested systems. Tau3 is distinct from Tau2-bench; it focuses on the full voice-to-result loop rather than isolated task completion by a language model.
Architecture and Pricing Model
The model is a front-end layer, not a complete agent. The $0.05/min rate covers the voice input/output handling; backend reasoning and action execution cost separately at whatever model the developer connects. OpenAI’s example pairing — GPT-Live-1 for voice, GPT-6 Astra for reasoning, Codex for code execution — makes the full-stack cost a function of task type.
That split pricing is the practical difference from GPT-Realtime-2.1, which bundled voice and reasoning into one token-based rate. Separating the voice layer lets OpenAI price the front end like infrastructure and the intelligence like an API call.
Context: The Voice API Progression
OpenAI shipped GPT-Realtime-2 in May 2026, GPT-Realtime-2.1 in July 2026, and GPT-Live in the same month. GPT-Live-1 in the API on September 10 is the third distinct voice-layer product in four months. The cadence reflects pressure from ElevenLabs, Hume, and native speech-to-speech evaluations that ranked GPT-Realtime behind newer entrants on naturalness and latency.
GPT-Live-1 is available immediately through the OpenAI API. OpenAI says it will continue releasing newer models into the front-end voice layer as they become available.