{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "#/components/schemas/SendTransactionalEmail",
  "title": "SendTransactionalEmail",
  "type": "object",
  "required": [
    "sender",
    "to"
  ],
  "properties": {
    "sender": {
      "type": "object",
      "description": "The sender identity for the email.",
      "properties": {
        "name": {
          "type": "string",
          "description": "Display name of the sender."
        },
        "email": {
          "type": "string",
          "format": "email",
          "description": "Email address of the sender."
        }
      }
    },
    "to": {
      "type": "array",
      "description": "List of recipient email addresses and optional names.",
      "items": {
        "type": "object",
        "required": [
          "email"
        ],
        "properties": {
          "email": {
            "type": "string",
            "format": "email",
            "description": "Recipient email address."
          },
          "name": {
            "type": "string",
            "description": "Recipient display name."
          }
        }
      }
    },
    "cc": {
      "type": "array",
      "description": "List of CC recipient email addresses.",
      "items": {
        "type": "object",
        "properties": {
          "email": {
            "type": "string",
            "format": "email",
            "description": "CC recipient email address."
          },
          "name": {
            "type": "string",
            "description": "CC recipient display name."
          }
        }
      }
    },
    "bcc": {
      "type": "array",
      "description": "List of BCC recipient email addresses.",
      "items": {
        "type": "object",
        "properties": {
          "email": {
            "type": "string",
            "format": "email",
            "description": "BCC recipient email address."
          },
          "name": {
            "type": "string",
            "description": "BCC recipient display name."
          }
        }
      }
    },
    "subject": {
      "type": "string",
      "description": "Subject line of the email. Required if not using a template."
    },
    "htmlContent": {
      "type": "string",
      "description": "HTML body content of the email. Required if not using a template."
    },
    "textContent": {
      "type": "string",
      "description": "Plain text body content of the email as a fallback."
    },
    "templateId": {
      "type": "integer",
      "format": "int64",
      "description": "ID of the template to use for the email content."
    },
    "params": {
      "type": "object",
      "description": "Dynamic parameters for template personalization as key-value pairs.",
      "additionalProperties": true
    },
    "replyTo": {
      "type": "object",
      "description": "Reply-to address for the email.",
      "properties": {
        "email": {
          "type": "string",
          "format": "email",
          "description": "Reply-to email address."
        },
        "name": {
          "type": "string",
          "description": "Reply-to display name."
        }
      }
    },
    "attachment": {
      "type": "array",
      "description": "List of file attachments to include with the email.",
      "items": {
        "type": "object",
        "properties": {
          "url": {
            "type": "string",
            "format": "uri",
            "description": "URL of the attachment file to download and include."
          },
          "content": {
            "type": "string",
            "description": "Base64 encoded content of the attachment."
          },
          "name": {
            "type": "string",
            "description": "Filename of the attachment."
          }
        }
      }
    },
    "headers": {
      "type": "object",
      "description": "Custom email headers as key-value pairs.",
      "additionalProperties": {
        "type": "string"
      }
    },
    "tags": {
      "type": "array",
      "description": "Tags to categorize the email for tracking purposes.",
      "items": {
        "type": "string"
      }
    },
    "scheduledAt": {
      "type": "string",
      "format": "date-time",
      "description": "UTC date-time to schedule the email for future delivery."
    }
  }
}