Simon Willison · 2026-07-24
More than any of these eval scores, what is most exciting to me is something else: Opus 5 is our least prompt injectable model yet. It is a bit buried in the system card, but across PI evals and red teaming, Opus 5 is very hard to prompt inject successfully. — Boris Cherny, here…
Simon Willison · 2026-07-24
Introducing Claude Opus 5 I've been offline kayaking with sea otters for much of today so I haven't had a chance to put Anthropic's new model Claude Opus 5 through its paces yet. The buzz is positive, and Anthropic's description of it as a "thoughtful and proactive model that co…
Stratechery · 2026-07-24
The best Stratechery content from the week of July 20, 2026 including Chinese models and frontier futures, what happened to Hugging Face, and the NBA and its second apron bet.