curl --request GET \
  --url https://api.justpaid.io/api/v1/contract/{contract_id}/line-items \
  --header 'Authorization: Bearer <token>'

[
  {
    "uuid": "item-uuid",
    "name": "API Calls",
    "description": "Pay per API call",
    "billing_alias": "api_calls",
    "prices": [
      {
        "uuid": "price-uuid",
        "price": 0.001,
        "billing_cycle": "monthly",
        "price_type": "usage_based_fee",
        "recurring": false,
        "usage_based_unit": "calls",
        "usage_based_unit_price": 0.001,
        "min_units": 0,
        "max_units": null
      }
    ]
  }
]