tengu_ethereal_nova

A Claude Code feature flag, read out of the shipped bundle. It was in the build from v2.1.229 and was gone by v2.1.284.

Releases whose published page names tengu_ethereal_nova.

1. v2.1.238 20 Aug 2026
   A /design command that drafts a design on a canvas artifact

   A /design command that drafts a design on a canvas artifact now registers by default, if your account allows it.

   gate cited by this entry, found in this entry's text

2. v2.1.238 20 Aug 2026
   The /design skill prompt was rewritten and its page seeder gained warnings

   The /design skill got stricter rules and now demands a path, a description and a favicon emoji.

   gate cited by this entry, found in this entry's text

3. v2.1.238 20 Aug 2026
   The tengu_ethereal_nova gate's built-in default is now on

   A feature switch that used to default off now defaults on when the server says nothing.

   gate cited by this entry, found in this entry's text

4. v2.1.234 17 Aug 2026
   Design canvas skill pins a runtime version and gains explicit failure paths

   The design canvas skill pins a fixed runtime version and adds refusal paths, behind an off-by-default flag.

   named in this entry, gate cited by this entry, found in this entry's text

5. v2.1.229 12 Aug 2026
   New /design skill drafts multi-artboard canvases as an Artifact, gated off

   A /design skill drafting multi-artboard canvases as editable Artifacts is bundled but switched off.

   gate cited by this entry, found in this entry's text

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.

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.

The earliest release whose published evidence quoted tengu_ethereal_nova was v2.1.238, 20 Aug 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.

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.

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.