Claude Opus 5.5 officially launched on B.AI, with API and Web Chat available simultaneously

On September 23, the B.AI platform announced that the first model of Anthropic's newly released Claude 5.5 series, Claude Opus 5.5, is officially online, with API and Web Chat both open for simultaneous experience. This model is designed for long-cycle Agent programming and complex knowledge work, achieving Claude Fable 5.1 levels in most tasks, while reducing operating costs by about 40% compared to Opus 5.

The model supports 1M Token ultra-long context and up to 128K output, demonstrating leading capabilities in Computer Use and multi-step automation scenarios. From today, developers and users can directly access Claude Opus 5.5 through the B.AI platform. You are welcome to log in to chat.b.ai/chat to experience it immediately.