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.

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...