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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 v2.1.237 Home All releases olderv2.1.236 v2.1.238newer
Claude Code v2.1.237

New built-in output style "Concise"

Use it now
Useful4 Signal2
Output Styles

You can now pick a "Concise" output style so Claude leads with results and skips narration.

/output-style
What

A fifth built-in style joins Proactive, Explanatory and Learning. Described as "Claude responds tersely, leading with results and skipping preamble and narration", it tells the model to lead with the result, cut narration, answer simple questions in 1-3 sentences and never trade correctness for brevity. Nothing gates its registration, so anyone on this build can pick it from the output-style list unless output styles are turned off entirely.

Details
  • Registered as a built-in style with coding instructions retained, so normal engineering guidance still applies.
  • Its system prompt is headed "# Concise Style Active" and states explicitly that it overrides more general communication guidance, backed by six rules plus a short reminder re-injected each turn.
  • Reported in prompt telemetry under its own key rather than collapsing into the generic one.
Evidence

Claude responds tersely, leading with results and skipping preamble and narration, The user chose brevity over narration. You should:

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 v2.1.237 →