curl -X GET "https://api.rapidcall.ai/api/agents/agent_9k2m4n6p/usage-summary?startDate=2026-03-01T00:00:00Z" \
  -H "Authorization: Bearer YOUR_API_KEY"

{
  "agentId": "agent_9k2m4n6p",
  "agentName": "Sales Assistant",
  "period": {
    "startDate": "2026-03-01T00:00:00Z",
    "endDate": "2026-03-31T23:59:59Z"
  },
  "tokens": {
    "totalInput": 1842560,
    "totalOutput": 924180,
    "model": "gpt-4.1",
    "estimatedCost": 12.47
  },
  "tts": {
    "totalMinutes": 287.4,
    "provider": "cartesia",
    "estimatedCost": 8.62
  },
  "stt": {
    "totalMinutes": 412.1,
    "provider": "deepgram",
    "estimatedCost": 2.06
  },
  "telephony": {
    "totalMinutes": 412.1,
    "estimatedCost": 3.30
  },
  "totalEstimatedCost": 26.45
}