MQTT Commander

Connect to your broker and the topic tree fills in within seconds, with the latest value next to each topic. Tap one to see the value in large type, a sparkline of how it moved, and the JSON split field by field.

FOUR SCREENS, ONE JOB EACH
• Topics: the tree of what your broker publishes, with filters for what changes, what is retained, what you pinned
• Board: pinned topics as live tiles, so one look tells you the greenhouse sits at 21.4 °C and the pump went quiet 6 minutes ago
• Log: messages in order, with presets for errors, your own publishes and retained values
• Publish: a topic, a payload, Send. QoS, retain, content type and expiry sit one tap away

USE IT TO
• Watch Home Assistant, Zigbee2MQTT, Mosquitto and ESPHome without opening a laptop
• Find the topic a new device announced itself on
• Read a JSON payload by field and compare it with the message before
• Send a test message and see what the broker answers, including a refusal
• Clear a retained payload that keeps coming back

WHEN IT WON'T CONNECT
Connection Doctor walks the connection in 14 stages and names the one that failed: DNS, TCP, TLS handshake, certificate chain, expiry, hostname, ALPN and SNI, CONNACK, authentication, protocol version, and a write test against the broker ACL. You get the stage, the reason and what to change, instead of a red banner.

PRIVACY
Values that look like tokens, passwords or keys stay behind a tap. Exported logs carry hashed topics and metadata, no payloads. Anonymous crash and usage diagnostics are on by default and switch off in Settings. No ad tracking, no data sold.

PRO
The app is free: watch topics, read payloads, publish with QoS and retain, run the Connection Doctor, pin five topics to the Board and keep the first one on your Home Screen as a widget. Pro is a one-time unlock with no subscription, and it covers the part that runs while you look elsewhere: Lock Screen widgets and the other Home Screen widgets, pins without a limit, history that survives a restart, whole-broker discovery, more broker profiles, one certificate reused across every broker, saved commands with Siri and Shortcuts, log export as CSV or JSON, and the full Doctor report to share. Bought the paid app before it went free? You keep Pro at no cost.

WORKS WITH
Home Assistant, Mosquitto, Zigbee2MQTT, ESPHome, Node-RED, ESP32 and ESP8266, and any broker speaking MQTT 3.1.1 or 5.0 over TCP, TLS, mTLS or WebSocket.

REQUIREMENTS
• iOS 17 or later, iPhone and iPad
• Local Network access for brokers on your LAN

Demo mode lets you look around before you connect anything.