OpenAI DevDay 2026 applications are now open!
Our biggest developer event gets even bigger.
📍 San Francisco
📅 September 29
Apply by July 10: https://t.co/BJyK2EbKuu
Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family.
It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.