tengu_model_capability_from_client_data
A Claude Code feature flag, read out of the shipped bundle. It was in the build from v2.1.305 and was gone by v2.1.307.
Claude can narrate what it's about to do and post progress updates; set CLAUDE_CODE_TURN_UPDATES.
Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.229.
In the changelogs
2Releases whose published page names tengu_model_capability_from_client_data.
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v2.1.239
Two model behaviours can be switched on by a server payload
Two model behaviours, a silent turn reminder and a Bash-output audience note, can be forced on by env vars.
gate cited by this entry, found in this entry's text
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v2.1.229
"Turn updates" narration style for Claude's replies
Claude can narrate what it's about to do and post progress updates; set CLAUDE_CODE_TURN_UPDATES.
gate cited by this entry, found in this entry's text
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_model_capability_from_client_data was v2.1.239, 21 Aug 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
4One 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.