Claude Opus 4.8: The System Card

2026-06-01

Claude Opus 4.8, released only six weeks after Opus 4.7, comes with a 244-page system card. While the updates are incremental, there is still a lot to talk about. Its capabilities are still well behind Mythos. This post looks at the system card, what's different between the two versions, and what this reveals about Mythos.