# Delayed publish

# Create module

Open EMQ X Dashboard (opens new window), click the "Modules" tab on the left, and choose to add:


Select delayed publish module, no need to configure parameters, directly open


# Introduction to delayed publish

The delayed publication function of EMQ X can realize the function of delaying the publication of PUBLISH packets according to the time interval configured by the user. When the client uses the special subject prefix $delayed/{DelayInteval} to publish messages to EMQ X, the delayed publishing function will be triggered.

The specific format of the delayed publish topic is as follows:


-$delayed: All messages that use $delay as the subject prefix will be regarded as messages that need to be delayed. The delay interval is determined by the content in the next topic level. -{DelayInterval}: Specify the time interval for delaying the publication of this MQTT message, in seconds. The maximum allowed interval is 4294967 seconds. If {DelayInterval} cannot be parsed as an integer number, EMQ X will discard the message and the client will not receive any information. -{TopicName}: Topic name of MQTT message.


-$delayed/15/x/y: Publish the MQTT message to topic x/y after 15 seconds. -$delayed/60/a/b: Publish MQTT message to ʻa/bin 1 minute. -$delayed/3600/$SYS/topic: MQTT messages will be published to$SYS/topic` in 1 hour.