{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "https://raw.githubusercontent.com/api-evangelist/nylas/main/json-schema/nylas-transactional-send-message-schema.json", "title": "transactional_send_message", "x-generated": "2026-10-02", "x-method": "derived", "x-generator": "derive-json-schema.py", "x-source": "openapi/nylas-transactional-send-api-openapi.yml#/components/schemas/transactional_send_message", "type": "object", "properties": { "id": { "type": "string", "description": "The message ID." }, "attachments": { "type": "array", "description": "An array of Attachment objects. For google, linked Google Drive files are not included. For Microsoft, linked One Drive files are not included.", "items": { "$ref": "#/$defs/attachment_transactional_send" }, "uniqueItems": true, "minItems": 0 }, "bcc": { "type": "array", "description": "An array of name/email address pairs that the message was BCC'd to. For received messages, this\nis nearly always empty.", "items": { "$ref": "#/$defs/message-participant" } }, "body": { "type": "string", "description": "The body of the message. This field is the same as the `body` field in your request." }, "cc": { "type": "array", "description": "An array of name/email address pairs that the message was CC'd to.", "items": { "$ref": "#/$defs/message-participant" } }, "from": { "type": "array", "description": "A list of name/email address pairs that the message was sent from. For transactional send, this will always be one pair.", "items": { "$ref": "#/$defs/message-participant-response" }, "uniqueItems": true }, "object": { "type": "string", "description": "The object type of the response (in this case, `message`)." }, "reply_to": { "type": "array", "items": { "$ref": "#/$defs/message-participant" }, "uniqueItems": true, "description": "An array of name/email address pairs that should receive replies to the message." }, "snippet": { "type": "string", "minLength": 1, "description": "A short snippet (the first 100 characters, with HTML tags removed) of the message body. This is\nuseful for displaying a preview of the message." }, "subject": { "type": "string", "description": "The subject of the message." }, "tracking_options": { "type": "object", "description": "Tracking options for the message.", "properties": { "opens": { "type": "boolean", "description": "When `true`, shows that message open tracking is enabled." }, "links": { "type": "boolean", "description": "When `true`, shows that link clicked tracking is enabled." }, "label": { "type": "string", "description": "A label describing the message tracking purpose.", "maxLength": 2048 } } }, "to": { "type": "array", "description": "An array of name/email address pairs that the message was sent to.", "items": { "$ref": "#/$defs/message-participant" }, "uniqueItems": true } }, "$defs": { "attachment_transactional_send": { "description": "A file attachment for a transactional email message.", "type": "object", "properties": { "content_type": { "type": "string", "minLength": 1, "description": "The [MIME type](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types) of the attachment, used by the email client to determine how to display the attachment. If you don't provide a type, Nylas infers it from the file name.\nThe value of this field is exactly the same as the email attachment's `Content-Type` header.\nThe provider might set additional parameters, such as `name` and `charset`.\n\nNylas returns an empty `content_type` field if an attachment file name contains non-ASCII characters (for example, accented characters like `ΓΌ`). This is because Google can't detect its content type." }, "filename": { "type": "string", "minLength": 1, "description": "The file name of the attachment." }, "content_id": { "type": "string", "description": "(Inline attachments only) The alphanumeric `cid` from the `` tag in the message's HTML. For\nexample, you might see something like `` in\nthe message body.\n\nSometimes, the `content_id` value is contained in angle brackets (for example,\n``)." }, "content_disposition": { "type": "string", "description": "(Not supported for Microsoft and EWS) The content disposition of the attachment. Usually, this is `inline` or `attachment` followed by the file name (for example, `inline; filename=\"some-image.jpeg\"`)." }, "is_inline": { "type": "boolean", "description": "If `true`, indicates that the attachment is an inline file." }, "size": { "type": "integer", "description": "The size of the attachment, in bytes." } } }, "message-participant": { "title": "Message participant", "type": "object", "description": "A name/email address pair.", "properties": { "name": { "type": "string" }, "email": { "type": "string", "format": "email" } }, "required": [ "email" ] }, "message-participant-response": { "title": "Message participant response", "type": "object", "description": "A name/email address pair.", "properties": { "name": { "type": "string" }, "email": { "type": "string", "format": "email" } } } } }