# clm_9517CB8B9A84

subject: Claude (/record/claude.md)  
predicate: model_release  
value: Sonnet 4.5  
valid_from: 2025-09-29  
valid_to: null  
published: 2025-09-29  
recorded: 2026-10-31  
confidence: 0.70  
status: valid  
assertable: true  
superseded_by: null  
last_updated: 2026-10-31  
checked: 2026-10-31 · its source page states the value and the date  

> September 29, 2025 Claude Sonnet 4.5 launch We released our newest model, Sonnet 4.5.

What https://support.claude.com/en/articles/12138966-release-notes#2025-09-29 says, word for word.

## Sources

- https://support.claude.com/en/articles/12138966-release-notes#2025-09-29 (primary, Anthropic, published 2025-09-29)

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