Debugging in LoT Notebooks means confirming data is moving on the right topics and your logic behaves as intended. The extension includes a Data Viewer and an Execution Trace tied to each LoT cell so you can see data, replay flows and inspect every related topic and variable.
Without the right view, you are mostly in the dark — you write code hoping nothing goes wrong. The Data Viewer and the execution trace light up the room, showing what that code actually did.
LoT MQTT Topic Tree Viewer, showing topic hierarchy and MQTT Payloads
The topic tree gives you a quick glance at your hierarchy and live values as messages arrive—handy for spotting whether a sensor topic or alert is updating, without needing to open a separate tool.Use Subscribe to All topics when you want the tree to show all broker data, and Subscribe to a topic when you want to focus on specific information.
Choose a formatter after opening a topic. The full viewer supports multiple topics, a message history, replay (timeline and playback controls), and data views such as raw, JSON, Protobuf, geopoint, image, audio and PDF.
Data Viewer Geopoint formatter: coordinates on a map
Execution trace: topics and variables for the LoT cell, with timeline and replay
The execution trace lets you see every topic and variable the cell touches—publishes, subscriptions, and related state—in one place, follow a time-ordered history of messages across them, and use replay with playback controls and a timeline to play, pause, and scrub the run. That way you can confirm execution order, timing, and which step produced which message when logic spans several topics.It is scoped to the LoT cell you are debugging, so you stay with that cell’s footprint on the broker instead of hunting traffic across the whole system.
