Subagents

A subagent is an independent child agent session this session spawns. It runs in the same project directory with its own fresh context, works with the same tools, and hands back one final report. It cannot see this conversation, and you cannot see its progress except through its report and subagent_status. At most 4 run at once per session, and a subagent cannot spawn its own.

Reach for subagents when work is parallelizable and self-contained: sweeping several parts of a codebase, reviewing independent files, researching separate questions, or generating alternatives to compare. Skip them for small sequential tasks — a subagent costs a session start and only communicates once.

Tools

• subagent — spawn one child and wait for its report (up to 15 minutes; a child still working after that keeps running and stays reachable). Call it several times in one turn to fan out — the calls run concurrently.
• subagent_list — every child this session spawned, with the run ids the other tools need.
• subagent_status — one child's state and whatever report text it has written so far; usable mid-run.
• subagent_stop — stop one running child and free its slot; returns its partial work.

Writing the task

The task is the child's entire world — it has no memory of this chat. Include: