Anthropic says Opus 5 is its least prompt-injectable model so far
Simon Willison · rss · 2026-07-25
Simon Willison quotes Boris Cherny saying that, more than the headline eval scores, the most exciting part of Opus 5 is its resistance to prompt injection.
According to the system card, and specifically the section on page 73, Opus 5 is described as Anthropic’s least prompt-injectable model so far, with strong results across PI evals and red-teaming.
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