Anthropic releases a new version of the Claude API, removing sampling parameters such as temperature.

PANews October 22 news, according to ClaudeDevs, Anthropic has launched Claude API version 2026-10-21, which is the first official version since 2023. The new version removes the temperature, top_p, and top_k parameters from the Messages API. Passing documents in assistant turns, or passing citations in user turns, will return a 400 error. Some deprecated Admin and Enterprise Analytics API fields have also been replaced. Anthropic stated that the old version 2023-06-01 is not deprecated, and that versions will be released more frequently in the future so developers can handle incompatible changes before new model requirements. The Anthropic SDK and ant CLI have simultaneously released new major versions that use 2026-10-21 by default and provide migration guides.