Mentioned in the evidence
- Claude API version 2026-10-21
- Anthropic client SDKs
- ant CLI
- Claude Models on Google Cloud (Anthropic managed)
- Claude Opus 5.5 fast mode on Google Cloud (Anthropic managed template EDITED)
Official sources
- Anthropic Claude release notes (changelog) ↗
We've released new versions of the client SDKs and the ant CLI that send API version 2026-10-21 by default: Python SDK 2.0.0, TypeScript SDK 1.0.0, C# SDK 13.0.0, Go SDK 2.0.0, Java SDK 3.0.0, PHP SDK 1.0.0, Ruby SDK 2.0.0, and ant CLI 2.0.0. See Switch to 2026-10-21.
- Anthropic Claude release notes (changelog) ↗
We've added the enforcement_status and enforcement_actions fields to user profiles, so you can see whether Anthropic has restricted or banned one of your end customers. To find the profiles that have an open restriction or ban, list your profiles with the new enforcement_status[]
- Anthropic Claude release notes (changelog) ↗
We've released API version 2026-10-21. Migrating to API version 2026-10-21 shows how to upgrade.
- Anthropic Claude release notes (changelog) ↗
We've launched Claude Models on Google Cloud (Anthropic managed), the Claude API operated by Anthropic and reached through your Google Cloud project. Google Cloud IAM controls access. Google Cloud Marketplace handles billing.
- Anthropic Claude release notes (changelog) ↗
The new SDK and CLI versions also have breaking changes that don't depend on the API version, and they are licensed under Apache 2.0 instead of the MIT License. See SDK and CLI changes.
This is a global change, verified against Anthropic’s own sources. It is not an assessment of your systems or your impact.