Source Intelligence
Follow Discord

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 v2.1.163 Home All releases ←olderv2.1.140 v2.1.165newer→
Claude Code v2.1.163

SubagentStop Hook Event

What

A new hook event fires when a subagent finishes, complementing the existing Stop event which fires when the main conversation agent finishes. The hook output's additionalContext field is delivered back to the subagent so it can continue and act on the feedback.

Details
  • Event name: SubagentStop
  • Available for command-based and prompt-based hooks
  • Hook output schema: { hookEventName: "SubagentStop", additionalContext?: string }
  • additionalContext is non-error feedback; the subagent continues execution so it can act on it
  • Prompt-based hooks now also explicitly support SubagentStop alongside Stop, UserPromptSubmit, and PreToolUse
Evidence

Schema literal for the new event (search for "Hook-specific output for the SubagentStop event")

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 v2.1.163 →