curl --request GET \
  --url https://{workspaceId}.clinia.cloud/mdm/v1/relationship-definitions \
  --header 'X-Clinia-API-Key: <api-key>'

{
  "meta": {
    "numPages": 123,
    "page": 123,
    "perPage": 123,
    "total": 123
  },
  "data": [
    {
      "from": "<string>",
      "to": "<string>",
      "relationshipMapping": {},
      "key": "<string>"
    }
  ]
}