tengu_thistle_grebe
A Claude Code feature flag, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.
Subagent nudging behaviour can be picked per model, but the whole feature stays behind a gate.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.219.
In the changelogs
3Releases whose published page names tengu_thistle_grebe.
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v2.1.227
Prompt section discouraging over-delegation to subagents
Claude can be told to stop over-spawning subagents for small tasks, but that guidance is absent by default.
gate cited by this entry, found in this entry's text
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v2.1.219
Subagent steering can be resolved per model
Subagent nudging behaviour can be picked per model, but the whole feature stays behind a gate.
gate cited by this entry, found in this entry's text
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v2.1.215
Subagent Delegation Steering via
CLAUDE_CODE_THISTLE_GREBEgate cited by this entry, found in this entry's text
Gate readings
3| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.227 read on another version | Not enough to say | no value returned | no value returned | not a boolean we can read |
| v2.1.219 read on another version | Not enough to say | no value returned | no value returned | not a boolean we can read |
| v2.1.215 read on another version | Not enough to say | no value returned | no value returned | not a boolean we can read |
Two arms, because they disagree: this account is the one account this site reads and anonymous is a baseline with no identity attached. A reading says nothing about your account, and off cannot rule out a rollout both readings sit outside of. What these readings can and cannot show.
Flag server, over time
12| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| anonymous | "default" | 2026-10-17T05:30:04Z | 2026-10-23T10:15:06Z | v2.1.302 to v2.1.309 |
| this account | "default" | 2026-09-10T21:47:12Z | 2026-10-23T10:15:06Z | v2.1.268 to v2.1.309 |
| anonymous | no longer carried | 2026-10-17T05:25:57Z | 2026-10-17T05:25:57Z | v2.1.302 |
| anonymous | "default" | 2026-08-19T04:25:04Z | 2026-10-17T05:10:04Z | v2.1.233 to v2.1.302 |
| this account | no longer carried | 2026-09-10T21:46:45Z | 2026-09-10T21:46:45Z | v2.1.268 |
| this account | "default" | 2026-09-08T20:36:15Z | 2026-09-10T17:40:05Z | v2.1.263 to v2.1.267 |
| this account | no longer carried | 2026-09-08T20:34:58Z | 2026-09-08T20:34:58Z | v2.1.265 |
| this account | "default" | 2026-09-06T02:40:05Z | 2026-09-08T18:45:05Z | v2.1.261 to v2.1.263 |
| this account | no longer carried | 2026-09-06T02:36:19Z | 2026-09-06T02:36:19Z | v2.1.263 |
| this account | "default" | 2026-08-14T22:10:05Z | 2026-09-06T01:55:04Z | v2.1.232 to v2.1.261 |
| anonymous | no longer carried | 2026-08-19T04:20:14Z | 2026-08-19T04:20:14Z | v2.1.233 |
| anonymous | "default" | 2026-08-14T22:10:05Z | 2026-08-19T03:45:04Z | v2.1.232 to v2.1.233 |
One row per unbroken stretch of one reading, newest first, from snapshots taken every twenty-five minutes or so. No longer carried is not off: it means the flag server stopped returning the gate at all, which is what a retired experiment looks like. The version column is what was installed when the reading was taken, not what caused it.
First cited
1The earliest release whose published evidence quoted tengu_thistle_grebe was v2.1.215, 19 Jul 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the feature flag does. All feature flags.