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 v2.1.215 Home All releases olderv2.1.214 v2.1.216newer
Claude Code v2.1.215

Marl Cormorant Feature Flag [In Development]

Feature flag
tengu_marl_cormorant Off in both readings

The flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.

This account: off · anonymous baseline: off · compiled default in v2.1.215: 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 v2.1.215. It isn't a statement about your account. What a flag value here can and cannot tell you

What

A new feature flag infrastructure point that can be toggled via the CLAUDE_CODE_MARL_CORMORANT environment variable or the tengu_marl_cormorant server-side flag.

Status

Feature-flagged — the flag is registered and the accessor function K_c() is in place, but no behavioral changes downstream of this flag are visible in the diff. The specific capability it gates is not yet apparent from the current code.

Details
  • The flag follows the same pattern as other binary feature gates: env var → client data → GrowthBook → false default.
  • When CLAUDE_CODE_MARL_CORMORANT is set to a truthy value the flag reads as enabled.
  • Concrete downstream effect: K_c() is called in exactly one place — the Dly() function that assembles the Bash tool's description string. When the flag is true, an extra bullet "- Command output is displayed to you, not reliably to the user." is appended to the Bash tool capability list (before the timeout note). When the flag is false (the default), that bullet is absent entirely. This means the "Bash Tool Clarifies Output Visibility" change described elsewhere in this release is itself gated on CLAUDE_CODE_MARL_CORMORANT — users without the flag see no change to the Bash tool description.
  • The injected bullet appears after the "avoid these commands" warning and before the timeout line, so it sits in the middle of the tool's operating-notes block, visible to Claude every time the Bash tool description is loaded.
  • No other call sites for K_c() are present in the source; the flag has no effect beyond this single bullet injection.
Evidence

K_c() called at line 428617 inside Dly()let l = K_c() ? ["- Command output is displayed to you, not reliably to the user."] : [] — the array is spread into the final description join at line 428627 (search for "Command output is displayed to you" near K_c)

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

See this entry in the whole of v2.1.215 →