Ask HN: How to rewrite `Claude.md` and install the skill for Opus5 and Fable5

3 points by hyhmrright 2 hours ago | 4 comments

Anthropic has released the new Opus 5 and Fable 5 models. Many existing resources—such as `claude.md` files and custom skills—are no longer compatible with these new models. How should one rewrite or adjust `claude.md`, or develop skills better suited to these models?

alvis 2 hours ago |

These models don't take claude.md, Claude Code does, and claude.md still get fed to these models if you're using Claude Code.

That said, prompting on opus 5 needs new technique: https://platform.claude.com/docs/en/build-with-claude/prompt...

hyhmrright 51 minutes ago | |

Thanks; the issue likely stemmed from the translation software used previously. I’ve seen many people online mention that removing skills like "superpowers" reduces token consumption and shortens completion times. I also read that Anthropic removed over 80% of the system prompts for Claude Code. I’m interested in finding out how to adjust `claude.md` and the installed skills to better optimize performance for the Opus 5 and Fable 5 models.

gojkoa 2 hours ago |

where did you get the "are no longer compatible" part? we moved from opus 4 to opus 5 without changing anything and no specific conflicts. used fable for a while, also did not have to change anything. I read some advice on the anthropic website that opus 5 doesn't require as many examples as before, but this was a recommendation how to make things shorter, not a backwards compatibility issue.

hyhmrright 50 minutes ago | |