This date has passed. If it just broke for you, what to do is below.
criticalShutdown
Claude Sonnet 3.7 is retired from the Claude API
- Announced
- 28 Oct 2025
- Effective
- passed 19 Feb 2026
- Source
- the vendor’s own page · last checked 23 Sept 2026
What breaks
Requests naming this model return an error from the retirement date. Nothing degrades gradually — the call simply stops working.
What to do
Move to claude-sonnet-4-6.
Advice confirmed 23 Sept 2026
What the vendor said
On 28 October 2025 Anthropic notified developers using claude-3-7-sonnet-20250219 of its upcoming retirement.