tengu_violin_heel
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.
On Linux, project hooks can now run in a bubblewrap sandbox with no network and a hidden home folder, when a server switch allows it
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.286.
In the changelogs
1Releases whose published page names tengu_violin_heel.
-
v2.1.286
Project hooks can run in a bubblewrap sandbox on Linux, behind a server switch
On Linux, project hooks can now run in a bubblewrap sandbox with no network and a hidden home folder, when a server switch allows it
gate cited by this entry, found in this entry's text
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.286 read on another version | Off by default, switched on for this account | on | on | off |
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
5| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | on | 2026-09-29T18:30:06Z | 2026-10-02T18:20:06Z | v2.1.284 to v2.1.287 |
| anonymous | on | 2026-09-29T18:25:06Z | 2026-10-02T18:20:06Z | v2.1.284 to v2.1.287 |
| this account | no longer carried | 2026-09-29T18:05:06Z | 2026-09-29T18:05:06Z | v2.1.284 |
| anonymous | off | 2026-09-29T16:50:07Z | 2026-09-29T18:05:06Z | v2.1.284 |
| this account | off | 2026-09-29T18:02:52Z | 2026-09-29T18:02:52Z | v2.1.285 |
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
2The earliest release whose published evidence quoted tengu_violin_heel was v2.1.286, 30 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 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.