Claude Opus 5.5: One Rumour, Three Names in 16 Days
Anthropic shipped Claude Opus 5.5 on 22 September at $4 and $20 per million tokens — the price and the day the leak named. The sixteen days before it were a different story: one unconfirmed release, three different names, and a chain that had already been wrong about two of them.
Anthropic model documentation
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