curl --request POST \
  --url https://api.revring.ai/v1/calls \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "agentId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
  "toNumber": "<string>",
  "fromNumber": "<string>",
  "variables": {}
}
'

{
  "data": {
    "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "organizationId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "direction": "INBOUND",
    "status": "INITIATED",
    "fromNumber": "<string>",
    "toNumber": "<string>",
    "initiatedAt": "2023-11-07T05:31:56Z",
    "createdAt": "2023-11-07T05:31:56Z",
    "updatedAt": "2023-11-07T05:31:56Z",
    "agentId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "sipTrunkId": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
    "agentCallerIdName": "<string>",
    "agentName": "<string>",
    "variables": {},
    "recordingUrl": "<string>",
    "hangupCause": "<string>",
    "errorMessage": "<string>",
    "transcript": [
      {}
    ],
    "summary": "<string>",
    "metrics": {},
    "startedAt": "2023-11-07T05:31:56Z",
    "endedAt": "2023-11-07T05:31:56Z",
    "durationSeconds": 123,
    "postCallWebhookStatus": "<string>",
    "preCallWebhookStatus": "<string>"
  }
}