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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial

Claude Code v2.1.239 ·

Per-model effort level in settings, behind a gate

You could set an effort level per model in settings, but the lookup is gated off.

Nothing to try yet Notable In Development
JSON All of v2.1.239
Nothing to try yetTier: how much it should matter to you
3Useful: my rating, 1 to 5
4Signal: worth watching, 1 to 5
SettingsArea: what it touches
In DevelopmentKind: in v2.1.239,
What probably matters to youSection of the release

modelSettings.<model>.effortLevel is written and read behind a flag falling back to false.

What

Any settings layer can set modelSettings.<model>.effortLevel, which overrides the top-level effortLevel for that one model, with model ids normalised before lookup. Saving effort to user settings writes both the top-level key and the per-model entry. The lookup is gated on tengu_russet_plover, which falls back to false, so absent a server value the per-model table stays empty and effort behaves exactly as before.

Details
  • Session effort is now a tagged value: an explicit level, the default, or inherited.
Evidence

tengu_russet_plover

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

Read from
Names in the bundleeffortLevelmodelSettings
Feature flag
tengu_russet_plover Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.239: off

Read once, for one account on one subscription tier, against v2.1.239. It isn't a statement about your account. What a flag value here can and cannot tell you

Since it was published

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 since Anthropic's documentation has since written up effortLevel, on Configuration reference. The effort level the default model (the first `inferenceModels` entry, or the first model your endpoint returns under discovery) starts at in Chat, Cowork and Code, in place of Anthropic's recommended level for that model: one of `low`, `m… third-party/claude-desktop/configuration see the edit
Added since A small documentation edit on CLI reference touched a line naming modelSettings after this was published. | `--effort` | Set the [effort level](/docs/en/model-config#adjust-effort-level) for the current session. Options: `low`, `medium`, `high`, `xhigh`, `max`, or `ultracode`. Available levels depend on the model. `ultracode` requests `xhigh` … cli-reference see the edit
Added since A small documentation edit on Agent SDK reference - TypeScript touched a line naming effortLevel after this was published. `effortLevel` accepts an [effort level](/docs/en/model-config#adjust-effort-level) name. It also accepts `"ultracode"`, which requests `xhigh` effort with [ultracode](/docs/en/workflows#let-claude-decide-with-ultracode) on. `applyFlagSetti… agent-sdk/typescript see the edit
What has happened since
Flag reading moved The flag server now returns on for tengu_russet_plover, read as this account. A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
Flag reading moved The flag server now returns nothing at all, having stopped carrying it for tengu_russet_plover, read as this account. A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.

See this across every release →

How sure we are
Two sources agreeTwo things we can check say the same as this entry.
Anthropic's documentation agreesA small documentation edit on Agent SDK reference - TypeScript touched a line naming effortLevel after this was published.
The name it cites is new in this buildNew in this build: modelSettings

See this entry in the whole of v2.1.239 →

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