tests/fixtures/hooks/subagent_start.json

{
  "session_id": "fixture-session",
  "transcript_path": null,
  "cwd": ".",
  "hook_event_name": "SubagentStart",
  "model": "gpt-5.3-codex-spark",
  "permission_mode": "default",
  "turn_id": "fixture-turn",
  "agent_id": "fixture-agent",
  "agent_type": "worker"
}