Source Intelligence

DisclaimerUnofficial, and not affiliated with Anthropic. Nearly all of this is read straight out of what ships: npm bundles, captured prompts, published docs. Anthropic's own notes go in verbatim, marked as theirs. The rest is my reading, and every entry carries the strings behind it. If one looks wrong, vote it down and say why.

All of v2.1.163 Home All releases olderv2.1.140 v2.1.165newer

Velvet Falcon Model Detection [In Development]

Feature flag
tengu_velvet_falcon_model Not enough to say

Nothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.

This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.163: not a boolean we can read

These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.

Read once, for one account on one subscription tier, against v2.1.163. It isn't a statement about your account. What a flag value here can and cannot tell you

What

Infrastructure to detect and handle a new internal model variant identified as "velvet falcon."

Status

Gated by tengu_velvet_falcon_model feature flag; also overrideable via CLAUDE_CODE_VELVET_FALCON environment variable.

Details
  • The model string is fetched from clientDataCache.velvet_falcon_model first, then from the feature flag.
  • Detection returns true when the session's model string includes the configured identifier.
Evidence

Detection function (search for "tengu_velvet_falcon_model" and "CLAUDE_CODE_VELVET_FALCON")

Strings lifted out of the shipped bundle, so the claim above can be checked against them.

See this entry in the whole of v2.1.163 →