curl --request GET \
  --url https://integrations.clopos.com/open-api/customer-groups \
  --header 'x-brand: <api-key>' \
  --header 'x-token: <api-key>' \
  --header 'x-venue: <api-key>'

{
  "success": true,
  "data": [
    {
      "id": 1,
      "name": "My Customers",
      "discount_type": null,
      "discount_value": 0,
      "system_type": "my_customers",
      "created_at": "2025-08-16T15:21:15.000000Z",
      "updated_at": "2025-08-16T15:21:15.000000Z",
      "deleted_at": null
    }
  ],
  "total": 1,
  "time": 71,
  "timestamp": "2025-10-24 05:38:15",
  "sorts": [
    "id",
    "name",
    "discount_type",
    "discount_value",
    "total_amount",
    "created_at",
    "updated_at",
    "deleted_at"
  ],
  "unix": 1761284295
}