Inside GPT-Live: full-duplex voice, one-round-trip startup
GPT-Live replaces turn-based voice architecture with streaming full-duplex inference: the turn-taking detector is removed from the audio path, the voice model listens and speaks simultaneously, and deeper reasoning or tool use is delegated asynchronously to GPT-5.5. Engineering details include a Go rewrite of the media front end that brings p95 frame delivery in line with the old p50; stateful handovers between model instances that turn context compaction into controlled failover without interrupting the media stream; and WARP, a set of backward-compatible WebRTC optimizations that cut session startup from six network round trips to one, plus Instant Connect to move SDP signaling off the critical path so a single UDP packet starts a session. Silent shadow testing showed CPU-side stream processing saturates before GPU inference under real traffic, shifting capacity planning from throughput to concurrent sessions. For engineers building realtime voice or agent interaction systems.