tengu_slate_lantern

A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.198, including the newest one read.

Releases whose published page names tengu_slate_lantern.

1. v2.1.274 16 Sep 2026
   Live-subscribe ('artifact watch') feature flag remains off by compiled default

   Explanation text for a disabled 'live-subscribe' artifact-watch feature was reworded

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

2. v2.1.257 1 Sep 2026
   Sync-transport auth handshake option (feature-flagged)

   Behind a flag, the sync-transport handshake can use a sync token instead of the existing live subscription token.

   gate cited by this entry

3. v2.1.257 1 Sep 2026
   Artifact live-subscribe gains agentPeer/syncLive eligibility check, off by default

   Artifact live-subscribe now checks agent-peer and sync-live eligibility before connecting, and it is off by default.

   gate cited by this entry

4. v2.1.250 27 Aug 2026
   Failed live-watch startups are treated as temporary outages and retried on the slow schedule

   Live artifact watches that fail to start from a server hiccup now retry on the patient schedule instead of burning attempts.

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

5. v2.1.239 21 Aug 2026
   Artifact watching now has three modes, and says which one you are in

   Artifact watch status now tells you plainly when live watching is switched off rather than staying vague.

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

6. v2.1.239 21 Aug 2026
   Artifact watching now has an explicit "not available here" state

   Claude is now told plainly when artifact watching isn't available, so it stops falsely promising to watch.

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

7. v2.1.236 19 Aug 2026
   New flag tengu_slate_lantern_ember for lease-based artifact auto-replies

   One new switch controls both early artifact comment reads and a lease-based auto-reply mode, off by default.

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

8. v2.1.233 14 Aug 2026
   --watch-artifact flag to follow a claude.ai artifact from a session

   A new --watch-artifact flag follows a claude.ai artifact for new versions and comments, but needs account access.

   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.

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.

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.