{
  "id": "usr_abc123",
  "external_id": "user-12345",
  "email": "jane.doe@example.com",
  "first_name": "Jane",
  "last_name": "Doe",
  "custom_attributes": {
    "plan": "pro",
    "team_id": "team_456"
  },
  "notification_preferences": {
    "categories": {
      "billing": {
        "in_app": true,
        "email": true,
        "mobile_push": false
      }
    }
  },
  "created_at": "2026-01-15T08:30:00Z",
  "updated_at": "2026-06-12T10:00:00Z"
}