Anthropic just released Claude Opus 5, their newest Opus-class model, and we've added it to Sudowrite.

According to Anthropic, Opus 5 comes close to the intelligence of their flagship Fable 5 model at half the price. It's a big jump over Opus 4.8 on reasoning and instruction-following benchmarks—which, for authors, means better Story Bible adherence and less plot drift. Early testers also report that Opus 5 may be more permissive than other models.

We haven't put Opus 5 through its paces on long-form fiction just yet, so we’re not ready to attest to its prose. The Opus line has historically been a favorite among Sudowrite authors for its warmth and character voice though, and on paper this is the strongest one yet—but you'll be finding out alongside us. Claude Opus 5 is available now in Write, Draft, and Plugins. Give it a spin and let us know what you think.