tengu_cozy_fern
A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.301, including the newest one read.
If an MCP tool asks to end the turn while a tool call in the same batch failed, Claude Code can now keep the turn going
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.301.
In the changelogs
2Releases whose published page names tengu_cozy_fern.
-
v2.1.302
Claude can be kept going after a request to end its turn from more sources
The note that can keep Claude's turn going after a failed tool call now applies to more than MCP tools, if switched on remotely
gate cited by this entry
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v2.1.301
A failed MCP tool call can stop Claude from ending its turn too early
If an MCP tool asks to end the turn while a tool call in the same batch failed, Claude Code can now keep the turn going
gate cited by this entry
Gate readings
2| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.302 read on another version | Not enough to say | no value returned | no value returned | off |
| v2.1.301 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.
Flag server, over time
6| Read as | Reading | From | Until | Version installed |
|---|---|---|---|---|
| this account | off | 2026-10-22T00:10:04Z | 2026-10-22T06:25:04Z | v2.1.307 to v2.1.308 |
| anonymous | off | 2026-10-20T20:20:05Z | 2026-10-22T06:25:04Z | v2.1.304 to v2.1.308 |
| this account | no longer carried | 2026-10-21T21:10:07Z | 2026-10-21T21:10:07Z | v2.1.306 |
| this account | off | 2026-10-21T21:09:42Z | 2026-10-21T21:09:42Z | v2.1.307 |
| this account | no longer carried | 2026-10-21T02:50:06Z | 2026-10-21T02:50:06Z | v2.1.305 |
| this account | off | 2026-10-21T02:45:34Z | 2026-10-21T02:45:34Z | v2.1.306 |
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.
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.
Presence across releases
1Build by build
8One 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.