kumomta/docs/reference/kumo.nats/publish.md

client:publish({PARAMS})

{{since('2026.03.04-bb93ecb1')}}

Sends a message. PARAMS is an object style table with the following keys:

• subject - required string; the name of the subject to which to send the message
• payload - required string; the message to send
• headers - optional NATS headers
• await_ack - optional wait for server acknowledgement (default: true)

In case await_ack is set to true, publish returns an acknowledgment with the following values:

• stream: name of stream the message was published to
• sequence: sequence number the message was published in
• domain: domain the message was published to
• deplicate: true if the published message was determined to be a duplicate, false otherwise
• value: used only when published against stream with counters enabled

nats:publish {
  subject = 'subject',
  payload = 'payload',
  headers = {
    ['Nats-Msg-Id'] = 'unique-id',
  },
  await_ack = true,
}