Claude API version 2026-10-21 released

Anthropic: Claude API version 2026-10-21 released, Wednesday, October 21, 2026, Claude Platform / Claude API. Ended.

Anthropic released API version 2026-10-21, along with new versions of the client SDKs and the ant CLI that send API version 2026-10-21 by default, licensed under Apache 2.0 instead of the MIT License. Anthropic also added enforcement_status and enforcement_actions fields to user profiles and a new enforcement_status[] filter when listing profiles.

Who’s involved

• Anthropic (host, organizer)

Tickets and details: docs.claude.com

Last updated 2026-10-22.