o1 API, 4o/4o-mini in Realtime API + WebRTC, DPO Finetuning

**OpenAI** launched the **o1 API** with enhanced features including vision inputs, function calling, structured outputs, and a new `reasoning_effort` parameter, achieving **60% fewer reasoning tokens** on average. The **o1 pro** variant is confirmed as a distinct implementation coming soon. Improvements to the **Realtime API** with **WebRTC** integration offer easier usage, longer sessions (up to **30 minutes**), and significantly reduced pricing (up to **10x cheaper** with mini models). **DPO Preference Tuning** for fine-tuning is introduced, currently available for the **4o** model. Additional updates include official Go and Java SDKs and OpenAI DevDay videos. The news also highlights discussions on **Google Gemini 2.0 Flash** model's performance reaching **83.6% accuracy**.