Anthropic resumes billing some pre-output Claude API refusals

Anthropic's Claude Platform release notes dated Sept. 24 say it is resuming billing for refusals that arrive before any output when stop_details.category is bio, frontier_llm or reasoning_extraction, the categories where it says false positives are low. Mid-stream refusals were already billed; pre-output refusals in other categories remain unbilled, fallback credit is unchanged, and billed refusals are charged at the rates of the model that ran the request on all named developer platforms. The notes give no refusal rate or bill-impact estimate.