What
A new "fork" agent type for the Task tool that creates a copy of the current conversation context to process a task in the background.
Status
Feature-flagged — only triggers when the fork experiment is active.
Details
- When the fork experiment is active, omitting
subagent_typefrom the Task tool creates a fork instead of using the general-purpose agent - Forks inherit the full conversation context from the parent
- Fork workers cannot create nested forks ("Fork is not available inside a forked worker")
- Uses
permissionMode: "bubble"to propagate permission requests to the parent - System prompt indicates: "You are a forked worker process" with worktree context awareness
- Maximum 200 turns per fork
Evidence
Fork agent definition (search for "You are a forked worker process") and fork config (search for "Implicit fork")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.