tengu_modular_marble
A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.323, including the newest one read.
Claude Code dropped four server-controlled experiment switches and added many others, nearly all off unless switched on remotely
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.323.
In the changelogs
3Releases whose published page names tengu_modular_marble.
-
v2.1.323
The set of server-controlled experiments has changed
Claude Code dropped four server-controlled experiment switches and added many others, nearly all off unless switched on remotely
gate cited by this entry, found in this entry's text
-
v2.1.323
Deferred tools can come with "when to use" hints, behind a remote setting
A remote setting can now make Claude Code add "when to use" hints when it tells the model about tools it has not loaded yet
gate cited by this entry
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v2.1.323
Two new remote switches do nothing unless the server turns them on
Claude Code now checks two new remote switches whose purpose is not stated, and both stay off unless the server sends a value
gate cited by this entry
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.323 read on another version | Not enough to say | no value returned | off | 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
6| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | off | 2026-11-13T02:10:04Z | 2026-11-13T03:40:04Z | v2.1.323 |
| anonymous | off | 2026-11-11T06:40:04Z | 2026-11-13T03:40:04Z | v2.1.322 to v2.1.323 |
| this account | no longer carried | 2026-11-13T00:05:05Z | 2026-11-13T00:05:05Z | v2.1.323 |
| this account | off | 2026-11-12T23:20:05Z | 2026-11-12T23:55:05Z | v2.1.323 |
| this account | no longer carried | 2026-11-12T22:25:04Z | 2026-11-12T22:25:04Z | v2.1.323 |
| this account | off | 2026-11-11T06:55:04Z | 2026-11-12T22:20:07Z | v2.1.322 to v2.1.323 |
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_modular_marble was v2.1.323, 12 Nov 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
1Build by build
1One 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.