I've been at Anthropic through every model launch. There's been a few cases I can remember of a launch that stands out and marks a step-change in how we use models:
– Claude Opus 3
– Claude Sonnet 3.5
– Claude Opus 4.5

And now Claude Fable 5.

With Fable, the model stopped… https://t.co/PVivAMNL1X

— Alex Albert (@alexalbert__) 9 juin 2026

I was at Anthropic for every model launch. There have been a few cases that I remember where a launch stood out and marked a step change in how we use models:
– Claude Opus 3
– Claude Sonnet 3.5
– Claude Opus 4.5
And

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