This is very interesting! It might be pushing the bubble around a bit if it fails on the undefined variable, but maybe this can fail more gracefully. I'll experiment with this and report back. Thanks for the idea!

Sadly, this doesn't work. HA preserves the state of the "started" variable, so the second time you boot up, it already exists and is set to 1 when the automatons are loaded, but before pyscript is ready. Is there a way to keep HA from making the variable persistent? For future posterity, this is what I did. @time_trigger("startup") def pyscript_started(): pyscript.started = 1 This goes anywhere in the python script. Then in the automation that calls the script, add this condition. condition: numeric_state entity_id: pyscript.started above: 0 It seems like the condition fails gracefully if the state doesn't exist, and prevents the action from happening and failing.

Yes, that would work for a clean shutdown or reboot, but not for a power cycle. Odds are, this will work for 99.99% of the cases that I care about...I'll give it a try.