tengu_cosmic_lake
A Claude Code feature flag, read out of the shipped bundle. It has been in the build since v2.1.282, including the newest one read.
Default false. When on, the rate-limit-warning notification (the warning shown as a usage limit gets close) is skipped when the limit status is allowed_warning and the limit type is five_hour. Warnings for other limit types still show.
Not Anthropic's. Written by Claude Opus 5.5 from reading the v2.1.286 bundle, and it can be wrong.
In the changelogs
0No changelog entry here has ever named it. That is a statement about what has been written, not about the name: it has been in the build since v2.1.282 without anybody writing a line about it.
Gate readings
0No release here has a gate table behind it for this flag. Most published releases have none at all: the readings exist only for versions the pipeline captured flag state on.
First cited
1The earliest release whose published evidence quoted tengu_cosmic_lake 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
1Build by build
14One 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.