tengu_copper_heron
A Claude Code feature flag, read out of the shipped bundle. It was in the build from v2.1.282 and was gone by v2.1.283.
Behind a remote switch, skills named claude-ai: or anthropic-skills: must really come from the matching source to be used
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.282.
In the changelogs
3Releases whose published page names tengu_copper_heron.
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v2.1.282
Synced skills can't pose as Anthropic-named skills once a new switch is on
Behind a remote switch, skills named
claude-ai:oranthropic-skills:must really come from the matching source to be usedgate cited by this entry
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v2.1.282
Settings overrides for skills synced from claude.ai now also match their other names
Overrides for account-synced skills now also check their alias names, and two remote switches change how synced skill names are handled
gate cited by this entry, found in this entry's text
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v2.1.282
Calling a skill by its old prefix now suggests the current name
If Claude calls a synced skill by its former namespace, the Skill tool now suggests the skill's current full name instead of only reporting it unknown
gate cited by this entry
Gate readings
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.282 read on another version | Not enough to say | no value returned | no value returned | 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.
First cited
1The earliest release whose published evidence quoted tengu_copper_heron was v2.1.282, 24 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
2Build by build
2One 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.