[Anthropic Releases New Version of Claude API, Removes Sampling Parameters Like Temperature] According to ClaudeDevs, Anthropic launched the Claude API version on 2026-10-21, marking the first official release since 2023. The new version has removed the temperature, top_p, and top_k parameters from the Messages API. Passing documents in the assistant turn or citations in the user turn will result in a 400 error. Some deprecated fields in the Admin and Enterprise Analytics APIs have also been replaced.