Change stream · Claude Platform release notes
On Claude Fable 5.1 and Claude Mythos 5.1, tool_choice types any and tool aren't supported and return a 400 error.
1 Sep 2026 · Anthropic Claude
No access to your tenant or devices. Every item links to its source. What this means
Change stream · Claude Platform release notes
1 Sep 2026 · Anthropic Claude