Develop QuickApps on your laptop — meet flua

We all know the HC3 edit-save-test cycle: open the web editor, tweak a line, save, wait for the QA to restart, watch the debug console, repeat. flua runs your QuickApp on your laptop, against a simulated HC3 — no controller involved, no risk to the house, instant feedback. The very same file runs on the real HC3 when you are done.

flua is a small command-line tool (Python + a bundled Lua engine). Install it once:

pip install fibaro-flua

In a new project folder, create quickapp.lua:

--%%name:HelloLamp
--%%type:com.fibaro.binarySwitch

function QuickApp:onInit()
  self:debug("Hello from", self.name, self.id)
end

The --%% lines are HC3 QuickApp declarations — flua reads the same header the HC3 uses. Run it:

flua --ui 8090 quickapp.lua

Open http://127.0.0.1:8090/ — that is the UI viewer: your QA, its device, and its controls rendered like the HC3 client. The log line appears in the terminal, immediately. No save button, no waiting.

For VS Code users, one command sets everything up (launch configurations, tasks, even agent instructions):

flua --tool setup

Then just press F5 — the "Run Current File (UI)" configuration runs the QA you are editing and opens the viewer. Debugging configurations come with it too (more on that in a later post).

Notice the pattern that makes F5 work without flags: nearly everything flua can take on the command line can also be set as a --%% directive in the QA file itself — the name, the type, the UI, the clock, the mode. The file carries its own scenario; the command line just runs it.

What you got for free just now: a simulated HC3 with your device on it, a virtual clock, and a viewer — the same QuickApp API the real controller gives you. Next post: designing the UI for your QA, without leaving the laptop.

flua is open source: https://github.com/jangabrielsson/flua · docs: USAGE.md and docs/tutorial/ in the repo.