FluxMQ
Concepts

Topics

Topic names, filters, and wildcard matching rules

Topics

Last Updated: 2026-02-05

FluxMQ uses MQTT-style topics across protocols. Topics are hierarchical strings separated by /.

Topic Examples

  • sensors/temperature
  • orders/created
  • $queue/orders
  • $SYS/broker/clients/connected
  • $share/workers/sensors/#

Topic Filters (Subscriptions)

MQTT wildcard rules apply:

  • + matches a single level (sensors/+)
  • # matches multiple levels (sensors/#)

These same patterns are used by queue topic bindings as well.

Special Namespaces

Some prefixes are reserved for broker features:

PrefixPurpose
$SYS/...Broker stats topics (published periodically, retained).
$queue/<name>/...Durable queue traffic (stored in queue logs, delivered via consumer groups).
$share/<group>/<filter>Shared subscriptions (MQTT): load-balanced pub/sub delivery.

Queue Topics ($queue/)

Queue traffic uses the $queue/ prefix. For example:

  • $queue/orders (publish)
  • $queue/orders/# (subscribe)
  • $queue/orders/$ack (ack a delivery)

FluxMQ treats $queue/<name>/... as:

  • name: the durable queue name
  • everything after name/: the queue routing key (used for pattern matching inside the queue)

For MQTT, durable queue behavior is triggered by the $queue/ prefix. A publish to a non-$queue/ topic uses normal pub/sub routing.

Learn more in Durable queues.

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