What
Claude Code ships a signed, static backup list of models to use if it can't fetch the live model catalog. In this release, the default model for two of the listed surfaces, 'ccr' and 'ccd', changed from claude-sonnet-4-6 to claude-opus-5. The 'cc' surface entry was already set to claude-opus-5 and is unchanged.
Why
If Claude Code ever falls back to this offline catalog, users on the 'ccr' and 'ccd' surfaces will now get claude-opus-5 by default instead of claude-sonnet-4-6.
Names in the bundleclaude-opus-5
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on model-deprecations touched a line naming claude-opus-5 after this was published.
| claude-opus-5-5 | Active | N/A | Not sooner than September 22, 2027 |about-claude/model-deprecations see the edit
Confirmed since
Anthropic's documentation has since written up claude-opus-5, on claude-in-microsoft-foundry.
| Claude Opus 5 | `claude-opus-5` | ✓ | ✓ |build-with-claude/claude-in-microsoft-foundry see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up claude-opus-5, on claude-in-microsoft-foundry.