curl -X GET https://api.rapidcall.ai/api/billing/summary \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "billing": {
    "plan": "pay_as_you_go",
    "periodStart": "2026-04-01T00:00:00Z",
    "periodEnd": "2026-04-30T23:59:59Z",
    "monthToDateTotal": 142.87,
    "ongoingTotal": 1.24,
    "paidThisPeriod": 0.00,
    "phoneNumbers": {
      "count": 3,
      "monthlyCost": 9.00
    },
    "breakdown": {
      "llm": 78.42,
      "tts": 34.15,
      "stt": 11.20,
      "telephony": 10.10,
      "phoneNumbers": 9.00
    },
    "hasPaymentMethod": true,
    "currency": "USD"
  }
}