curl --request GET \
  --url https://api.politicalcomms.com/v1/ledger/usage \
  --header 'X-API-Key: <api-key>'

{
  "success": true,
  "data": {
    "organization_id": "org_123",
    "organization_name": "Smith Campaign 2024",
    "period": {
      "start_date": "2026-01-01",
      "end_date": "2026-01-31"
    },
    "totals": {
      "messages_sent": 1452300,
      "sms_charges": 14523,
      "mms_charges": 0,
      "carrier_lookup_charges": 125,
      "10dlc_charges": 129.5,
      "total_charges": 14777.5
    },
    "by_category": [
      {
        "category": "sms",
        "units": 1452300,
        "amount": 14523
      },
      {
        "category": "carrier_lookup",
        "units": 25000,
        "amount": 125
      },
      {
        "category": "10dlc",
        "units": 1,
        "amount": 129.5
      }
    ]
  }
}