curl --request GET \
  --url https://app.useboom.ai/api/v1/cdp/relationship-types \
  --header 'Authorization: Bearer <token>'

{
  "personToCo": [
    {
      "relationshipTypeId": "rt_2hk9",
      "role": "placed",
      "customObjectType": "order",
      "cardinality": "ONE_TO_MANY",
      "description": "A person who placed an order",
      "bidirectional": false
    }
  ],
  "coToCo": [
    {
      "relationshipTypeId": "rt_8fa1",
      "role": "contains",
      "parentCustomObjectType": "order",
      "childCustomObjectType": "line_item",
      "cardinality": "ONE_TO_MANY",
      "description": null,
      "bidirectional": false
    }
  ]
}