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 v2.1.251 Home All releases olderv2.1.250
Claude Code v2.1.251

One-time nudge when reasoning effort is set to high

Not switched on
Useful2 Signal3
Reasoning Effort

A one-time dialog may suggest lowering your reasoning effort, only if the server supplies wording.

The nudge is skipped entirely when its remote config text is absent.

Feature flag
tengu_radiant_island Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.251: not a boolean we can read

Read once, for one account on one subscription tier, against v2.1.251. It isn't a statement about your account. What a flag value here can and cannot tell you

What

A dialog can suggest changing your reasoning effort when it is set to "high". Its wording comes from the tengu_radiant_island remote config, and it is skipped when that config is absent. It also requires that onboarding is finished and that you have not seen it before.

Details
  • Records whether the high setting came from your own settings, and tags the shown copy as either "default" or "user_pin" for telemetry.
Evidence

hasSeenEffortMediumNudge

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 v2.1.251 →