Question about jq

$ jq --version
jq-1.4
$ cat zout | jq -r -M .
{
  "rbac-service": {
    "service_version": "0.6.38",
    "service_status_version": 1,
    "detail_level": "info",
    "state": "running",
    "status": {
      "db_up": true,
      "activity_up": true
    }
  },
  "activity-service": {
    "service_version": "0.3.6",
    "service_status_version": 1,
    "detail_level": "info",
    "state": "running",
    "status": {
      "db_up": true
    }
  },
  "classifier-service": {
    "service_version": "1.5.15",
    "service_status_version": 1,
    "detail_level": "info",
    "state": "running",
    "status": {
      "environment_sync": true,
      "db_up": true,
      "rbac_up": true,
      "activity_up": true
    }
  }
}

Desired output: (need the value of the "state" key from the child dictionaries)

{
  "rbac-service": "running",
  "activity-service": "running",
  "classifier-service": "running"
}

For future reference, this is the answer I received when I asked about it on Freenode #jq ...

$ cat zout | jq -r -M 'with_entries(.value |= .state)'
{
  "activity-service": "running",
  "classifier-service": "running",
  "rbac-service": "running"
}