{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/Call",
  "title": "Call",
  "type": "object",
  "description": "Represents a call in Teams.",
  "properties": {
    "id": {
      "type": "string",
      "description": "Unique identifier for the call.",
      "example": "call-abc123"
    },
    "state": {
      "type": "string",
      "enum": [
        "incoming",
        "establishing",
        "ringing",
        "established",
        "hold",
        "transferring",
        "transferAccepted",
        "redirecting",
        "terminating",
        "terminated"
      ],
      "description": "Current call state.",
      "example": "established"
    },
    "direction": {
      "type": "string",
      "enum": [
        "incoming",
        "outgoing"
      ],
      "description": "Direction of the call.",
      "example": "outgoing"
    },
    "subject": {
      "type": "string",
      "description": "Subject of the call.",
      "example": "Quick sync"
    },
    "callbackUri": {
      "type": "string",
      "format": "uri",
      "description": "Callback URL for call notifications."
    },
    "requestedModalities": {
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "audio",
          "video",
          "videoBasedScreenSharing"
        ]
      },
      "description": "Requested communication modalities."
    }
  }
}