Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.239 Home All releases olderv2.1.238 v2.1.240newer
Claude Code v2.1.239

Per-model effort level in settings, behind a gate

Not switched on
Useful3 Signal4
Settings Notable

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

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

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: on

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

effortLevelmodelSettings
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.

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.239 →