Over the past six months, we shipped 30+ models, features, and upgraded tools for the API.Our changelog has been busy. Here’s what you may have missed for the API:New models• GPT-5.5• GPT-5.4 mini• GPT-5.4 nano• GPT-Realtime-2• GPT-Realtime-Whisper• GPT-Realtime-Translate• GPT-Image-2Agent building blocks• Agents SDK harness & sandbox• Skills in the Responses API• Server-side compaction• WebSocket mode• Hosted shellMore ways to build• Admin API enhancements• OpenAI CLI• Models on Amazon Bedrock