What it is
Live document reads gain new fields for tracking update sequence and a gated deadline option
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.267.
Presence across releases
1Build by build
12One 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.
First cited
0No 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
1| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.267 | 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.
Names beside it
Every feature flag in the inventory starting tengu_copper, up to twelve of them.
tengu_copper_foxForked subagents are on by default in interactive sessions; set CLAUDE_CODE_FORK_SUBAGENT to false to opt out. v2.1.138
tengu_copper_kestrelNo description from anybody. v2.1.234
tengu_copper_lanternNo description from anybody. v2.1.138
tengu_copper_thistleThe status line always calls MCP background work a "task" instead of sometimes saying "job". v2.1.161
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.