Diogenes was a fourth-century B.C. Greek philosopher known for his performance art. He is said to have roamed the streets of Athens in the middle of the day, carrying a lit lantern, crying out, "I am looking for an honest man." If that myth were modernized for the present day, we'd all be looking for an honest AI.

Anthropic is both announcing and releasing Claude Opus 4.8, a large language model it believes might have satisfied Diogenes' quest.

"One of the most prominent improvements in Opus 4.8 is its honesty," the company said Thursday in a blog post.

Now, perhaps, this new frontier model will behave itself better. Anthropic reports that Opus 4.8 is less likely to make unsupported claims. It's also more likely to tell you when it's uncertain of an answer.

"This is borne out in our evaluations, which show that Opus 4.8 is around 4x less likely than its predecessor to allow flaws in code it's written to pass unremarked," the company said.

In Claude Code, I found Opus 4.7 to be a substantial improvement over 4.6. While 4.6 would often misinterpret instructions or deliver erroneous results, Opus 4.7 regularly tells me that the way it first looked at a problem didn't work, and it's taking a different tactic. Recent project assignments have shown a much greater degree of understanding than with 4.6.