What it is
New internal flags added, including bashActFirstEnabled and three codename gates amber_astrolabe, bison_cairn, larch_cistern
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.275.
Presence across releases
4Build by build
24One 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.
First cited
1The earliest release whose published evidence quoted tengu_gorse_plover was v2.1.275, 17 Sep 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 above.
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.275 read on another version | Off in both readings | off | off | 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
10| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | off | 2026-09-10T21:47:12Z | 2026-09-22T05:45:05Z | v2.1.268 to v2.1.278 |
| anonymous | off | 2026-08-19T04:25:04Z | 2026-09-22T05:45:05Z | v2.1.233 to v2.1.278 |
| 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 | 2026-08-14T22:10:05Z | 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 | off | 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.
Names beside it
Every feature flag in the inventory starting tengu_gorse, up to twelve of them.
tengu_gorse_fathomNo description from anybody. v2.1.198
tengu_gorse_pylonClaude can post a quick 'on it' note in artifact comment threads before the real reply, off unless enabled. v2.1.232
tengu_gorse_sillA second fast-ack mode lets Claude pick a fixed numbered acknowledgment instead of writing one, off behind two gates v2.1.235
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.