What
- Claude Code used to force newly launched models (like a brand-new Opus or Fable release) to run at a reduced "launch effort" level for a period after release, controlled by settings such as
unpinOpus47LaunchEffort,unpinOpus48LaunchEffort, andunpinFable5LaunchEffort. - A new mechanism now walks the list of newly-launched models (
claude-opus-4-7,claude-opus-4-8,claude-fable-5, and whateverANTHROPIC_DEFAULT_FABLE_MODELresolves to) and keeps each pinned to the launch effort level unless the matching unpin setting is turned on. - For a genuinely first-ever install of this build (no
firstStartVersionrecorded yet), the whole pin list is skipped, so brand-new installs start unpinned. - The three unpin settings were removed from the default client config store, and the model-recency list used for feature gating now includes claude-opus-4-6, claude-opus-4-7, claude-opus-4-8, and claude-sonnet-4-6.
Why
This keeps existing installs behaving the same (still pinned to a conservative effort level for brand-new models) while letting fresh installs and future models participate in feature gating and default effort without extra config.
Names in the bundleopus-4-6opus-4-7opus-4-8sonnet-4-6
Documented inapi/about-claude/model-deprecations
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 overview touched a line naming sonnet-4-6 after this was published.
<Card title="System prompt" icon="text" href="https://platform.claude.com/docs/en/release-notes/system-prompts/overview#claude-sonnet-4-6">models/sonnet-4-6/overview see the edit
Added since
A small documentation edit on prompting-claude-opus-4-8 touched a line naming opus-4-8 after this was published.
This guide covers the prompting patterns specific to Claude Opus 4.8. For the API changes involved in moving from Claude Opus 4.8 to Claude Opus 5.5, see [Migrating to Claude Opus 5.5 from Claude Opus 4.8](https://platform.claude.com/docs/…build-with-claude/prompt-engineering/prompting-claude-opus-4-8 see the edit
Added since
A small documentation edit on fast-mode touched a line naming opus-4-6 after this was published.
Fast mode is not available on Claude Opus 4.6. Requests to `claude-opus-4-6` with `speed: "fast"` do not return an error: they run at standard speed and are billed at [standard rates](https://platform.claude.com/docs/en/about-claude/pricin…build-with-claude/fast-mode see the edit
Added since
A small documentation edit on fast-mode touched a line naming opus-4-7 after this was published.
Fast mode is not available on Claude Opus 4.7. Requests to `claude-opus-4-7` with `speed: "fast"` return an error; unlike Claude Opus 4.6 (see the following note), requests do not fall back to standard speed. The model itself remains avail…build-with-claude/fast-mode see the edit
Confirmed since
Anthropic's documentation has since written up sonnet-4-6, on Create a Message Batch.
- `"claude-sonnet-4-6"`api/beta/messages/batches/create see the edit
Confirmed since
Anthropic's documentation has since written up opus-4-6, on Create a Message Batch.
- `"claude-opus-4-6"`api/beta/messages/batches/create see the edit
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
The finding does not say whether these model IDs correspond to models already released or ones expected in the future.
Anthropic's documentation agrees
Anthropic's documentation has since written up opus-4-8, on claude-api-skill.