You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
AgentsArea: what it touches
ImprovementsKind: in v2.1.283,
ImprovementsSection of the release
Unclear What makes a model choice count as refused under the new check is not clear.
What
The SDK lets other programs (called hosts) run Claude Code and control it. A host can send apply_flag_settings to change settings, including the model. Claude Code now has an extra check that can refuse the model sent this way. When it does, the model is not applied, and a restricted-model warning names the default model and the model actually in effect.
Before, the model was refused only when it was blocked and had no step-down model to fall back to.
Why
A host that changes the model this way may now see the change refused and replaced by a warning, rather than applied.
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.
Confirmed sinceAnthropic's documentation has since written up apply_flag_settings, on Hooks reference.| `source` | string | Where the request came from: `"command"` for `/model <name>`, the Model setting in `/config`, or turning on fast mode; `"picker"` for a model picker; `"sdk"` for a `set_model` request, or a model change in an `apply_f…hookssee the edit
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtWhat makes a model choice count as refused under the new check is not clear.
Anthropic's documentation agreesAnthropic's documentation has since written up apply_flag_settings, on Hooks reference.
