User Teases That OpenAI's Post-Training Team Is Cooking an 'Opus 4-5' Rival

sloppenheimer · x · 2026-09-24

User sloppenheimer teased OpenAI's post-training team with "you're doing an Opus 4-5," implying OpenAI is training a model to rival Anthropic's Claude Opus 4.5. The tweet includes a screenshot; details are unconfirmed and this is not an official statement.

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