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 v2.1.117 Home All releases olderv2.1.116 v2.1.118newer
Claude Code v2.1.117

/fork Command

Feature flag
tengu_copper_fox 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 v2.1.117: no gate table built for this version

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 v2.1.117. It isn't a statement about your account. What a flag value here can and cannot tell you

What

Spawn a background agent fork that inherits the full conversation context and executes a specific directive independently.

Usage
/fork <directive>
Details
  • The fork receives the parent conversation's full history as read-only reference context
  • Each fork executes ONE directive, then stops — it is not a continuation of the parent
  • Fork prompts should be specific directives about what to do, not descriptions of the situation
  • The fork agent name is auto-generated from the first few words of the directive
  • Requires at least one conversation turn before forking (you'll see "Cannot fork before the first conversation turn" if attempted too early)
  • Controlled by the tengu_copper_fox feature flag or CLAUDE_CODE_FORK_SUBAGENT environment variable
Evidence

Fork command handler (search for "Usage: /fork") — mp1 at line ~548474; fork spawner _n7 at line ~548333

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

See this entry in the whole of v2.1.117 →