OpenAI Realtime GA + Realtime-mini tier: production-grade voice agents cross the always-on threshold

OpenAI's GPT Realtime model page documents the GA of the production voice tier (server-side VAD, mid-session system-instruction updates, function calling during live sessions) and the launch of a Realtime-mini tier targeted at always-on voice agents. With GA, voice-agent creators can ship production traffic against a stable API; the Realtime-mini tier is positioned for high-volume / always-on assistants where cost-per-conversation dominates economics. The combination of GA stability, mid-session system-instruction updates, and a low-cost tier creates the conditions for voice agents to move from demo to product.