Narration summaries sit behind a flag that is off unless server config or CLAUDE_CODE_SABLE_THRUSH turns it on, and the VS Code extension is now told its state.
Claude Code sends the VS Code extension a map of experiment flags at startup, and that map gains one entry, tengu_sable_thrush, so the IDE side can branch on whether narration summaries are enabled. The flag is off by default in this build unless a server config turns it on. Set CLAUDE_CODE_SABLE_THRUSH to force it on or off in either direction.
- The value comes from the narration module's own check: the environment variable wins if set, otherwise the remote flag is consulted with an in-source fallback of false.
- The result is read once and latched for the process; a test-only helper exists to clear that latch.
- The flag itself is not new, it already drove narration-summary rendering in 2.1.240. What is new is that its state is shared with the extension.
- What the extension does with the value lives outside this build.
tengu_sable_thrush: (Cmr(), ln(uYr)).isSableThrushEnabled(),
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_sable_thrush Off by default, switched on for this accountThe shipped code defaults this off, and the flag server returned on for the one account this site reads on this version. That is the reading that makes the entry above worth a second look, and it still says nothing about your account.
This account: on · anonymous baseline: on · compiled default in v2.1.241: off
Read once, for one account on one subscription tier, against v2.1.241. It isn't a statement about your account. What a flag value here can and cannot tell you
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.
A reading is one sample. Claude Code evaluates its flags remotely, so no client sees the targeting rule behind a value and this says nothing about your account.