What it is
Claude Code now strips invisible characters like zero-width marks from pasted or typed text before sending it
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.277.
Presence across releases
1Build by build
3One 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
1The earliest release whose published evidence quoted tengu_tranquil_cloud was v2.1.277, 18 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 above.
Gate readings
2| Release | Resolved | This account | Anonymous | Compiled default |
|---|---|---|---|---|
| v2.1.280 read on another version | Not enough to say | no value returned | no value returned | on |
| v2.1.277 read on another version | Not enough to say | no value returned | no value returned | on |
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_tranquil, up to twelve of them.
tengu_tranquil_crescentClaude Code adds three new internal feature gates: typed_koala, zinc_harbor, tranquil_crescent never mined
tengu_tranquil_fernResuming a session that was in plan mode now puts you back in plan mode. v2.1.239
tengu_tranquil_summitAuto mode now stops itself instead of looping forever when safety checks keep failing v2.1.280
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.