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MQTT Configuration

This section describes settings that control the behavior of the MQTT protocol in YedMQ.

[mqtt]
sys_topic_interval_secs = 10
inflight_retry_interval_secs = 10
default_authentication = "deny"
default_authorization = "deny"
max_message_size = 268435456
Configuration ItemDescriptionDefault Value
sys_topic_interval_secsInterval for publishing system status to $SYS topics.10
inflight_retry_interval_secsInterval for retrying unacknowledged (Inflight) messages.10
default_authenticationDefault result when no authentication plugin handles a connection. Options: allow, deny.deny
default_authorizationDefault result when no authorization plugin handles an action. Options: allow, deny.deny
max_message_sizeMaximum allowed size (in bytes) for a single MQTT packet.268435456 (256MB)

The shipped configuration keeps these defaults aligned with a secure first-run posture. For the current broker runtime, MQTT access is also governed by the plugin-host fallback values in Plugin Configuration, which are set to deny by default as well.