When the tengu_gault_kestrel flag is active (or CLAUDE_CODE_GAULT_KESTREL env var is set), the system-prompt caution about checking file contents before overwriting or deleting is shortened. Specifically, the phrase "if what you find contradicts how it was described, or you didn't create it, surface that instead of proceeding" is removed from the instruction.
Feature-flagged — controlled by CLAUDE_CODE_GAULT_KESTREL / tengu_gault_kestrel. Only affects users who have this flag enabled.
- The full existing instruction reads: "Before deleting or overwriting, look at the target — if what you find contradicts how it was described, or you didn't create it, surface that instead of proceeding."
- With the flag enabled it becomes: "Before deleting or overwriting, look at the target." — the challenge-and-surface clause is dropped.
- This likely experiments with whether the longer cautionary phrase causes Claude to be overly hesitant or to block legitimate operations.
Conditional omission of the surface-on-contradiction phrase, gated by Y_c() which checks "tengu_gault_kestrel" (search for "if what you find contradicts how it was described")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_gault_kestrel Off in both readingsThe 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 v2.1.215: not a boolean we can read
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.215. It isn't a statement about your account. What a flag value here can and cannot tell you
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.
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.