Claude Opus 5.5 and Sonnet 5.5 are on our platform.
Anthropic's Claude Opus 5.5 reached our production platform on 22 September, and Claude Sonnet 5.5 on 29 September, both through Microsoft Azure AI Foundry. Neither is yet used for client work, and that is by design: we move an agent to a new model only after comparing the two on that agent's own work.
Where Claude is used today
Claude Opus 5 writes our longest documents, such as a sector note drafted from two years of research. Claude Sonnet 5 reviews new standing instructions for risk before they take effect, and builds the writing-style profile that allows drafts to read like the person sending them.
Before any agent moves
Each of those agents will be replayed on the 5.5 model against its own checks, and a person will review the comparison. An agent moves only if the new model performs at least as well on that agent's work. This is how every model change on the platform is made, as described on Models.
For Opus, the price alone makes the comparison worthwhile. At list price, Opus 5.5 costs $4 per million input tokens and $20 per million output tokens, against $5 and $25 for Opus 5. Sonnet 5.5 is priced the same as Sonnet 5, at $2 and $10.
We will report the results here once the comparisons are complete.