{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://www.twilio.com/docs/schemas/twilio/message.json",
  "title": "Twilio Message",
  "description": "Represents an SMS or MMS message sent or received through the Twilio Messaging API, including delivery status, pricing, and metadata.",
  "type": "object",
  "properties": {
    "sid": {
      "type": "string",
      "pattern": "^(SM|MM)[0-9a-fA-F]{32}$",
      "description": "Unique 34-character identifier for the message (SM for SMS, MM for MMS)"
    },
    "account_sid": {
      "type": "string",
      "pattern": "^AC[0-9a-fA-F]{32}$",
      "description": "SID of the Twilio account that created the message"
    },
    "messaging_service_sid": {
      "type": ["string", "null"],
      "pattern": "^MG[0-9a-fA-F]{32}$",
      "description": "SID of the messaging service used to send the message"
    },
    "to": {
      "type": "string",
      "description": "Recipient phone number in E.164 format"
    },
    "from": {
      "type": "string",
      "description": "Sender phone number, short code, or alphanumeric sender ID"
    },
    "body": {
      "type": ["string", "null"],
      "maxLength": 1600,
      "description": "Text content of the message (up to 1600 characters)"
    },
    "status": {
      "type": "string",
      "enum": [
        "queued",
        "sending",
        "sent",
        "delivered",
        "undelivered",
        "failed",
        "receiving",
        "received",
        "accepted",
        "scheduled",
        "read",
        "partially_delivered",
        "canceled"
      ],
      "description": "Current delivery status of the message"
    },
    "direction": {
      "type": "string",
      "enum": [
        "inbound",
        "outbound-api",
        "outbound-call",
        "outbound-reply"
      ],
      "description": "Direction of the message relative to your Twilio account"
    },
    "num_segments": {
      "type": "string",
      "description": "Number of segments the message body was split into"
    },
    "num_media": {
      "type": "string",
      "description": "Number of media files associated with the message"
    },
    "price": {
      "type": ["string", "null"],
      "description": "Price of the message in the account currency"
    },
    "price_unit": {
      "type": "string",
      "description": "ISO 4217 currency code for the price"
    },
    "error_code": {
      "type": ["integer", "null"],
      "description": "Twilio error code if the message failed"
    },
    "error_message": {
      "type": ["string", "null"],
      "description": "Human-readable description of the error"
    },
    "date_created": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp when the message resource was created"
    },
    "date_updated": {
      "type": "string",
      "format": "date-time",
      "description": "ISO 8601 timestamp when the message was last updated"
    },
    "date_sent": {
      "type": ["string", "null"],
      "format": "date-time",
      "description": "ISO 8601 timestamp when the message was sent"
    },
    "api_version": {
      "type": "string",
      "description": "Twilio API version used to process the message"
    },
    "uri": {
      "type": "string",
      "description": "Relative URI for this message resource"
    },
    "subresource_uris": {
      "type": "object",
      "description": "URIs of related subresources",
      "properties": {
        "media": {
          "type": "string",
          "description": "URI for associated media resources"
        },
        "feedback": {
          "type": "string",
          "description": "URI for message feedback"
        }
      }
    }
  },
  "required": ["sid", "account_sid", "to", "from", "status", "direction"]
}