MQTT Overview
RESTHeartComing soon
The MQTT module bridges an external MQTT broker into RESTHeart. Incoming topic messages become Server-Sent Events, REST responses, MongoDB documents, or input to your own plugins.
It connects to any MQTT 3.1.1 or 5.0 broker — Mosquitto, HiveMQ, EMQX, AWS IoT Core — using hivemq-mqtt-client and exposes what it receives through ordinary RESTHeart plugins.
What it does
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Stream MQTT to HTTP clients — subscribe to broker topics and push messages to browser or API consumers as Server-Sent Events, with optional per-connection filtering, throttling, and window aggregation.
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REST access to the last message — expose the most recent message for any subscribed topic through a simple GET endpoint, backed by an in-memory cache.
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Persist to MongoDB — write incoming messages directly to a MongoDB collection through a buffered, fault-tolerant pipeline with dead-letter support.
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Plugin integration — inject the message router into your own RESTHeart plugin to process MQTT messages with full access to the RESTHeart framework.
Security
All HTTP-facing endpoints require authentication by default. Topic-level authorization is enforced through an ACL that maps roles to MQTT topic filters, using filter containment semantics — so a pattern granting sensors/+ will not inadvertently grant sensors/#.
Roadmap
Post-v1 work is tracked under #601: MQTT 5 shared subscriptions and user properties, an HTTP → MQTT publish endpoint, a WebSocket bridge, polyglot pipeline stages, replay from MongoDB via Last-Event-ID, a dead-letter REST API, metrics, schema validation, and a distributed single-writer mode.