tengu_sprightly_lagoon
A Claude Code feature flag, read out of the shipped bundle. It was in the build from v2.1.260 and was gone by v2.1.302.
Default false. When on, the checks for per-turn effort and per-turn timing both report unsupported, so requests carry no per-turn effort or now values and those checks add no per-turn-control-2026-07-01 beta.
Not Anthropic's. Written by Claude Opus 5.5 from reading the v2.1.285 bundle, and it can be wrong.
In the changelogs
0No changelog entry here has ever named it. That is a statement about what has been written, not about the name: it has been in the build since v2.1.260 without anybody writing a line about it.
Gate readings
0No release here has a gate table behind it for this flag. Most published releases have none at all: the readings exist only for versions the pipeline captured flag state on.
Flag server, over time
10| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| anonymous | off | 2026-10-17T05:30:04Z | 2026-10-22T07:55:04Z | v2.1.302 to v2.1.308 |
| this account | off | 2026-09-10T21:47:12Z | 2026-10-22T07:55:04Z | v2.1.268 to v2.1.308 |
| anonymous | no longer carried | 2026-10-17T05:25:57Z | 2026-10-17T05:25:57Z | v2.1.302 |
| anonymous | off | 2026-09-04T02:05:04Z | 2026-10-17T05:10:04Z | v2.1.260 to v2.1.302 |
| this account | no longer carried | 2026-09-10T21:46:45Z | 2026-09-10T21:46:45Z | v2.1.268 |
| this account | off | 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 | off | 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 | off | 2026-09-04T02:25:04Z | 2026-09-06T01:55:04Z | v2.1.260 to v2.1.261 |
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
0No release's published evidence quotes this name. The ledger indexes the Evidence lines of every changelog on this site, so this says nobody here has ever quoted it; it says nothing about how old the name is.
Presence across releases
4Build by build
44One row per release since the first build this name was read out of. Absent means the build was read and the name was not in it, never mined means no bundle for that release was ever archived, and a declared type or a default is only ever what that release's own bundle stated.
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.