Opus 5, which was launched just two months after its predecessor Opus 4.8, is said to be "much stronger at verifying its work and iterating carefully until it succeeds." This claim is backed by benchmark testing where Opus 5 successfully wrote its own computer vision pipeline in response to an incomplete prompt. Unlike Fable and Mythos, Opus 5 isn't burdened by a 30-day data retention policy that had raised privacy concerns among some users.