curl --request GET \
  --url https://api.zenskar.com/entitlements/customers_balances \
  --header 'organisation: <api-key>' \
  --header 'x-api-key: <api-key>'

{
  "results": [
    {
      "id": "123e4567-e89b-12d3-a456-426614174000",
      "name": "API Calls",
      "units": "calls",
      "type": "Quantity",
      "entitlement": "456e7890-e12b-34c5-d678-901234567890",
      "customer": {
        "id": "789e0123-e45f-67g8-h901-234567890123",
        "name": "Acme Corp",
        "email": "billing@acme.com"
      },
      "quantity": 10000,
      "quantity_used": 2500,
      "quantity_remaining": 7500,
      "active_from": "2024-01-01T00:00:00Z",
      "expiry_at": "2024-12-31T23:59:59Z",
      "created_at": "2024-01-01T10:30:00Z",
      "contract_id": "contract-uuid-123",
      "contract": {
        "id": "contract-uuid-123",
        "name": "Enterprise Plan 2024"
      },
      "product": {
        "id": "product-uuid-456",
        "name": "API Access Product"
      },
      "invoice": {
        "id": "invoice-uuid-789",
        "name": "INV-2024-001"
      },
      "event": "Invoice",
      "invoice_id": "invoice-uuid-789"
    },
    {
      "id": "234e5678-e90b-12d3-a456-426614174001",
      "name": "Storage",
      "units": "GB",
      "type": "Quantity",
      "entitlement": "567e8901-e23f-45g6-h789-012345678901",
      "customer": {
        "id": "890e1234-e56f-78g9-h012-345678901234",
        "name": "Tech Solutions Inc",
        "email": "accounts@techsolutions.com"
      },
      "quantity": 100,
      "quantity_used": 45.2,
      "quantity_remaining": 54.8,
      "active_from": "2024-01-15T00:00:00Z",
      "expiry_at": "2024-02-14T23:59:59Z",
      "created_at": "2024-01-15T14:20:00Z",
      "contract_id": "contract-uuid-456",
      "event": "Manual"
    }
  ],
  "next": "cursor_to_next_page",
  "total": 150
}