OpenAI Agents SDK v0.12.1: WebSocket Transport for Multi-Turn Runs, SIP Protocol Support

GitHub·medium signal

Released March 13, 2026, Agents SDK v0.12.1 adds opt-in WebSocket transport for OpenAI Responses models via responses_websocket_session() helper that enables a reusable shared provider across multi-turn runs — HTTP remains the default. RealtimeRunner now handles SIP protocol connections, broadening voice agent use cases. Breaking: Python 3.9 support dropped (EOL), and Agent#as_tool() return type narrowed from Tool to FunctionTool.