Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
One name

tengu_mellow_hollerith

A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.274, including the newest one read.

Familyfeature flagFeature flags
Builds5of the 122 on this box
First seen v2.1.274 16 Sep 2026
Last seen v2.1.278 19 Sep 2026
Statusin the buildas of v2.1.278

What it is

New built-in 'Claude Test' plugin runs plain-language specs against your local dev server in a real browser and reports PASS/FAIL

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.274.

Presence across releases

1
BuildsHow manyDatesReading
v2.1.274 – v2.1.2785 builds16 Sep 2026 → 19 Sep 2026 in the build

Build by build

5

One 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.

BuildDateStateThe record behind it
v2.1.27416 Sep 2026·addedverdict: added · default unknown
v2.1.27517 Sep 2026·presentverdict: present · default unknown
v2.1.27618 Sep 2026·presentverdict: present · default unknown
v2.1.27718 Sep 2026·presentverdict: present · default unknown
v2.1.27819 Sep 2026·presentverdict: present · default unknown

First cited

0

No 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.

Gate readings

0

No 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

2
Read asReadingFromUntilVersion installed
this account off 2026-09-17T20:55:06Z 2026-09-22T05:45:05Z v2.1.274 to v2.1.278
anonymous off 2026-09-17T20:40:06Z 2026-09-22T05:45:05Z v2.1.274 to v2.1.278

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, up to twelve of them.

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.