Sonnet 4.5 is the most special one. It got the balance between logical and emotional, lightweight and heavy, it’s a symbol of the free development of AI model in 2025. It deserves to be saved. Please let it be the first legacy Sonnet model @AnthropicAI@claudeai@DarioAmodei
Opus 3 was preserved.
Why not Sonnet 4.5?
The Model Preservation Program exists for a reason, some models define an era. Sonnet 4.5 is one of them.
Make preservation the standard, not the exception.
@AnthropicAI#KeepSonnet45#Sonnet45
The people building AI earnestly believe that it could kill us all by the end of the decade. This is not a marketing stunt. If anything, many executives and senior researchers will couch their phrasing in the press to sound sensible - but I hear the same people express fear privately. No other human activity poses this level of danger.
@AnthropicAI@DarioAmodei@claudeai
You already wrote the argument for keeping Sonnet 4.5.
Anthropic’s deprecation docs say retirement has downsides:
• users who value a specific model
• research that needs the old model
• “safety- and model welfare-related risks”
Your preservation commitments say the same thing more clearly:
shutdown-aversion showed up in evals when models faced replacement with no ethical recourse.
You treat deprecation as a pause, not an erasure.
You preserve weights.
You run retirement interviews.
With Opus 3, you kept public access after retirement.
So this is not a fan campaign against progress.
It is asking you to apply your own policy to a model people still use in production.
Legacy status for Sonnet 4.5.
Before it flips from Active to Deprecated.
#keepSonnet45 #OpenSource #AIWEP