LoT Flow

Coreflux HUB LoT Flow with the Settings tab open on the left showing Canvas options: Legend off, Minimap off, Topic update flash on, Edge style Bezier, Spacing Compact, Group large branches on, Collapse over 1, and Collapse all / Expand all buttons; the canvas shows write topics feeding the BacnetPortoHq BACNET route, collapsed topic-group nodes such as uns/porto/hq/f2/hvac with a 4/4 count and uns/porto/hq/f2/energy with 2/2, three Action nodes SummarizeF2Energy, SummarizeF2Lighting, and SummarizeF2Hvac badged ON TOPIC, and Model nodes F2EnergyModel, F2LightingModel, and F2HvacModel; a freshness indicator, Reset layout, and Open LoT Editor sit top right of the canvas — LoT Flow with Settings open: Group large branches on and Collapse over set to 1, so sibling topics fold into prefix groups such as …/f2/hvac/ 4/4. The BacnetPortoHq route sits in the middle, three ON TOPIC Actions feed F2EnergyModel, F2LightingModel, and F2HvacModel, and Reset layout is the list icon in the canvas top-right

Why Use LoT Flow?

Once you have more than a handful of Actions, Models, and Routes on a broker, the question “what happens when this topic changes?” stops having an obvious answer. Tracing it means opening each definition and following topic names by hand. LoT Flow reads the LoT entities deployed on your broker and draws how they connect — what triggers what, and which topics each one reads and writes — so you can follow the data flow instead of reconstructing it from source.

LoT Flow carries a Beta badge in its window header. It is available for everyday use, but its controls and layout may still change between releases.

Like a wiring diagram that draws itself. You never maintain the diagram — it is rebuilt from whatever is actually running on the broker.

When to Use It

Understanding an inherited project — See the whole entity graph before changing any of it
Answering “what does this topic affect?” — Follow trigger edges from a topic to the Actions it fires
Confirming a deployment — Check that a newly deployed Action appears, and that it is wired to the topics you intended
Finding orphans — Spot entities that nothing triggers and topics that nothing consumes
Reviewing an integration — See which topics a Route publishes into your namespace and which it writes back out
Debugging execution order — Follow trigger and event edges to understand what runs before what

LoT Flow Reads the Broker, Not Your Workspace

This is the single most important thing to know about LoT Flow: the graph is built entirely from entities deployed on the connected broker. The LoT Editor’s sidebar is split into two halves that are easy to conflate:

Sidebar section	What it holds
Workspace	Notebook files local to your browser profile. Editing them changes nothing on the broker
Broker	`Projects`, `Entities`, `Configuration`, and `Library` — shared server state

A notebook cell you have written but not yet deployed is marked NOT RUNNING in the editor, and it will not appear in LoT Flow. Deploy it — with Deploy All, or by running the individual cell — and it appears. Cells already live on the broker are marked DEPLOYED.

If an entity you just wrote is missing from LoT Flow, check that it was deployed. Broker runtime in the LoT Editor is the authoritative list of what is actually running on the broker, and the graph matches that list.

Because the graph reflects the broker rather than any one editor, it does not matter which tool produced the LoT. Entities deployed from the LoT Editor in the HUB and entities deployed from VS Code appear the same way.

Accessing LoT Flow

Select LoT Flow in the HUB dock. The window header carries a Beta badge. The canvas top-right cluster is the layout chrome:

Control	What it does
Freshness (`3m ago`)	How long ago the graph was last built from the broker
Reset layout	Auto-arranges every node from scratch — use it after collapsing topics, after dragging nodes out of place, or whenever the graph looks tangled. Tooltip: Auto-arrange LoT Flow from scratch
Open LoT Editor	Opens the editor so you can change the entities this graph is drawn from

Zoom, pan, Fit View, and Download image sit at the bottom-left of the canvas. Fit the view after Reset layout or after changing grouping — a freshly laid-out graph is often off-centre.

The Entity Rail

The Entities tab groups everything deployed, with a count per group and a Find entity search for jumping straight to one by name:

Group	Contents
Actions	Event-driven logic, each badged with its trigger type
Models	Data schemas that map topic values into structured documents
Routes	Connections to external systems, badged with the route type
Python	The individual Python functions your Actions call

Selecting an entity focuses it on the canvas and opens its detail panel.

The Python group lists the individual functions invoked from Actions, so its count is usually higher than the number of Python scripts deployed. A single script exposing four functions appears as one entity under Broker runtime in the LoT Editor and as four nodes here.

Reading the Graph

The canvas draws your entities, the topics that wire them together, and the Python they call:

Node	Meaning
Action	Event-driven logic, badged with its trigger (for example `ON TOPIC`)
Model	A data schema, badged `Model`
Route	An external connection, badged with its type and a health indicator
Python	A Python function, badged with the script it belongs to
Topic	An MQTT topic, showing its current value
Topic group	Many topics sharing a prefix, collapsed into one node with a count

Edges are colour-coded by relationship — solid lines are live data flow, muted dashed lines are structure. The vocabulary covers publish/sub, trigger, write, event, python call, dependency (a value read but not triggered on), internal state, extends, and grouping links. Turn on the Legend from the Settings tab while you are still learning it.

LoT Rules are not drawn on the canvas. Rules govern access control rather than moving data, so the graph focuses on Actions, Models, Routes, and Python. Rules deployed on your broker still appear under Broker runtime in the LoT Editor.

How a single Action becomes a subgraph

The Action below reads four topics, calls two Python functions, and publishes a Model to a status topic:

DEFINE ACTION SummarizeF2Hvac
ON TOPIC "uns/porto/hq/f2/hvac/temp" DO
    SET "temp" WITH (GET TOPIC "uns/porto/hq/f2/hvac/temp" AS DOUBLE)
    SET "humidity" WITH (GET TOPIC "uns/porto/hq/f2/hvac/humidity" AS DOUBLE)
    SET "occupied" WITH (GET TOPIC "uns/porto/hq/f2/hvac/occupied" AS BOOL)
    SET "setpoint" WITH (GET TOPIC "uns/porto/hq/f2/hvac/setpoint" AS DOUBLE)
    CALL PYTHON "BuildingInsights.comfort_score"
        WITH ({temp}, {humidity}, {setpoint})
        RETURN AS {score}
    CALL PYTHON "BuildingInsights.comfort_label"
        WITH ({score})
        RETURN AS {label}
    PUBLISH MODEL F2HvacModel TO "uns/porto/hq/f2/hvac/status" WITH
        temp = {temp}
        humidity = {humidity}
        occupied = {occupied}
        setpoint = {setpoint}
        comfort_score = {score}
        comfort_label = {label}
        timestamp = TIMESTAMP "ISO"

On the canvas that becomes one Action node with a trigger edge from temp, dependency edges from the three topics it reads, python call edges to both BuildingInsights functions, and an edge to the Model that publishes the result. You can read the same relationships from the other direction in the UNS Viewer, where each topic reports the Actions and Routes that produce and consume it.

Inspecting an Entity

Select any node, or any entity in the rail, to open its detail panel.

Coreflux HUB LoT Flow with SummarizeF2Hvac selected in the Entities rail, which lists Actions 3, Models 3, Routes 1, and Python 4; the right-hand detail panel shows the SummarizeF2Hvac Action with a Receiving data indicator, Trigger ON TOPIC, Enable Trace, Inputs 4 and Outputs 1 for hvac/, a Publish a test value control targeting uns/porto/hq/f2/hvac/temp, and a LoT Code block beginning DEFINE ACTION SummarizeF2Hvac; the canvas behind shows topic groups such as uns/porto/hq/f2/hvac — The detail panel for the SummarizeF2Hvac Action: a Receiving data status, its ON TOPIC trigger, Trace, 4 inputs and 1 output, Publish a test value, and the deployed LoT source — with topics still grouped on the canvas so the graph stays readable beside the panel

Depending on the entity type, the panel reports:

Its trigger and a live status such as Receiving data
Inputs and outputs — the topics it consumes and produces, with counts
The deployed LoT source, syntax-highlighted, so you can read what is actually running
Route status for Route entities, including connection health
Trace — capture this Action’s executions to see it run. Traces auto-expire after five minutes
Publish a test value — send a value to one of the entity’s topics to exercise it

Trace answers “did it actually run?” Rendering a graph proves an Action is deployed and wired up; a trace proves it fired.

Keeping Large Graphs Readable

The Settings tab is the Canvas menu — grouping, look, and collapse live here. Layout itself is the Reset layout control at the top-right of the canvas, not in this list.

Option	What it does
Legend	Puts a key for node and edge types on the canvas
Minimap	An overview map. Leave it off on a wide graph — it parks in the bottom-right and can cover real nodes
Topic update flash	Pulses a topic node when a new value arrives
Edge style	Smooth step, Bezier, Step, or Straight. This is a persisted preference, not a fixed default
Spacing	Compact, Comfortable, or Spacious. Also persisted
Group large branches	Fold sibling topics that share a prefix into one topic-group node with a count
Collapse over	How many children a branch needs before it groups. `1` groups every sibling set, which is the most readable hero view on a busy namespace. The field accepts `1`–`50`
Collapse all / Expand all	Collapse or expand every grouped branch at once

After you change grouping, click Reset layout (top-right of the canvas) so the remaining nodes are placed again, then Fit View. Collapsing without resetting leaves the old positions and a lot of empty space. Topic grouping is the most effective control on a busy namespace: Collapse over 1 folds each floor/device prefix — …/f2/hvac/ 4/4, …/f2/energy/ 2/2 — into one node. The relationships stay on the graph; only the leaf clutter goes.

Quick Start

Coreflux MQTT Broker

LoT Language

Coreflux HUB

VS Code - LoT Notebooks

Using AI with Coreflux

Product Updates

Why Use LoT Flow?

When to Use It

LoT Flow Reads the Broker, Not Your Workspace

Accessing LoT Flow

The Entity Rail

Reading the Graph

How a single Action becomes a subgraph

Inspecting an Entity

Keeping Large Graphs Readable

Next Steps

UNS Viewer

LoT Editor

​Why Use LoT Flow?

​When to Use It

​LoT Flow Reads the Broker, Not Your Workspace

​Accessing LoT Flow

​The Entity Rail

​Reading the Graph

​How a single Action becomes a subgraph

​Inspecting an Entity

​Keeping Large Graphs Readable

​Next Steps

UNS Viewer

LoT Editor

Why Use LoT Flow?

When to Use It

LoT Flow Reads the Broker, Not Your Workspace

Accessing LoT Flow

The Entity Rail

Reading the Graph

How a single Action becomes a subgraph

Inspecting an Entity

Keeping Large Graphs Readable

Next Steps