Support

support_message_create

Post a message into a support thread.

Tool

support_message_create

Post a message into a support thread.

Post a message into a support thread. A message has exactly one author: either an opaque external identifier from the client's own user base, or a support agent — never both and never neither. Direction, authorship and visibility are independent: an internal note may be inbound or outbound. Posting a message moves the parent thread's last reply timestamp. A message may carry files: create and finalize them first, then name them in attachmentIds. Through the public edge an agent author is accepted only if that agent carries no Lessly binding — a bot or the calling backend; an agent bound to a Lessly identity may author only from a signed-in session

Behavior

HTTP: POST /support/messages

Arguments

Name	Type	Required	Description
body	string	•	The message text, stored verbatim
threadId	string	•	Id of the thread this message belongs to
direction	string	•	inbound: written by the external end user. outbound: written by support, going out to them
visibility	string	—	Defaults to public when omitted. Internal notes are never shown to the end user
attachmentIds	array	—	Files this message carries, created with support_attachment_create and confirmed with support_attachment_finalize beforehand. Each must be an uploaded attachment of the same thread that no other message already carries; otherwise the whole message is refused. At most 10 per message
authorAgentId	string	—	The support agent of this product who wrote the message. Set this exactly when the message comes from inside the support contour; leave authorExternalId empty. An agent of another product is reported as not found
authorExternalId	string	—	Opaque identifier of the external end user in the client's own user base, stored verbatim. Set this exactly when the message comes from outside; leave authorAgentId empty

Response

Field	Type	Always	Description
id	string	•	Message id
body	string	•	The message text, byte-identical to what was stored
threadId	string	•	Thread this message belongs to
createdAt	string	•	ISO-8601 creation timestamp
direction	string	•	inbound: written by the external end user. outbound: written by support, going out to them
visibility	string	•	public: part of the conversation the external end user sees. internal: a note between agents that never leaves the support contour
attachments	array	•	Files this message carries, each with a freshly signed download URL. Empty when there are none. Attachments whose upload was never confirmed are never listed here
authorAgentId	string	•	The agent author, or null when the external end user wrote the message
authorExternalId	string	•	The external author, or null when an agent wrote the message

Try it

Post a message into a support thread.

When to use

Example

Ask your agent something like this:

Post a message into a support thread.

The agent will invoke support_message_create with these arguments:

{
  "body": "<body>",
  "threadId": "<threadId>",
  "direction": "<direction>"
}