Anthropic API 2026-09-24

The Compliance API Activity Feed no longer returns file names, project document names, or artifact titles. The `filename` and `title` fields on file, project document, and artifact activities are now always empty or omitted, including on activities recorded before this change. To look up a name or title by the ID on the activity, use a Compliance Access Key with the `read:compliance_user_data` scope. See Understand the Activity object.

We're resuming billing for refusals that arrive before any output when `stop_details.category` is `"bio"`, `"frontier_llm"`, or `"reasoning_extraction"`, the categories where we measure low volumes of false positives. Mid-stream refusals were already billed. Refusals billed under this change are charged like any other request, at the rates of the model that ran it. Refusals before any output in other categories are still not billed, and fallback credit is unchanged. This change applies on all platforms. See How refusals are billed.

The Compliance API local session endpoints are out of beta for Claude for Microsoft 365 sessions in Excel, PowerPoint, Word, and Outlook (`product_surface` values beginning with `office_agents`). See Sessions on users' machines.