# clm_80CB0DE87581

subject: Claude Sonnet 4 (/record/claude-sonnet-4.md)  
predicate: available_in  
value: [Vertex AI](/record/vertex-ai.md)  
valid_from: 2025-08-26  
valid_to: null  
published: 2025-08-26  
recorded: 2026-11-12  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-11-12  
cite: AsOf. "Claude Sonnet 4 available in: Vertex AI", as of 2025-08-26. Claim clm_80CB0DE87581, https://asof.is/claim/clm_80CB0DE87581, accessed 2026-11-13. Source: https://platform.claude.com/docs/en/release-notes/overview#2025-08-26.  
checked: 2026-11-12 · its source page states the value and the date, as read by an AI model  

> August 26, 2025  We’ve increased rate limits on the 1M token context window for Claude Sonnet 4 on the Claude API. The 1M token context window is now available on Vertex AI.

What https://platform.claude.com/docs/en/release-notes/overview#2025-08-26 says, word for word.

## Sources

- https://platform.claude.com/docs/en/release-notes/overview#2025-08-26 (primary, Anthropic, published 2025-08-26)

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