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 v2.1.239 Home All releases olderv2.1.238 v2.1.240newer
Claude Code v2.1.239

Two model behaviours can be switched on by a server payload

Use it now
Useful3 Signal4
System Prompt Notable not in their notes

Two model behaviours, a silent turn reminder and a Bash-output audience note, can be forced on by env vars.

CLAUDE_CODE_SILENT_TURN_REMINDERCLAUDE_CODE_BASH_OUTPUT_AUDIENCE_NOTE
What

A silent turn reminder and a new note telling Claude who will read Bash output now resolve the same way: an environment variable wins, then whatever the model catalog declares, then a cached blob of settings the server delivers. Anything else is off. In practice both are off unless the server enables them or you set CLAUDE_CODE_SILENT_TURN_REMINDER or CLAUDE_CODE_BASH_OUTPUT_AUDIENCE_NOTE yourself.

Details
  • The silent turn reminder previously came from a per-model experiment lookup; that path is gone.
  • The first time a given model takes a capability from the server payload it reports it once, tracked with a small cache of recently seen models.
Evidence

tengu_model_capability_from_client_data

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

Related

Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.

See this entry in the whole of v2.1.239 →