HomeKit to MQTT? (Triggering Node-RED via Apple Watch/Siri?)

As an iPhone user, I’ve had my eye on the Apple Watch for years but I’ve never taken the plunge due to A] the price and B] lack of any good way (AFAIK) to interface with HA. Now that prices have come down, I’m kinda champing at the bit to get one but the only IoT support is HomeKit. Now I’m wondering, what about somehow sending an MQTT message via HomeKit? There’s no shortage of HomeKit to MQTT bridges out there - but they’re all proprietary… Hue, WeMo, etc. Is there something out there (maybe an ESP32-based DIY project?) that could get the job done? I do all my automations in Node-RED so I just need it to listen for and receive an MQTT message that initiates via Siri or a button on the Apple Watch.

Apple Watch users - can you place a button that’s a shortcut to a web URL? If so, I think I could generate an MQTT message via a web link, right?

I’m not an iPhone user, but I have a similar issue with Alexa. I wanted to trigger a Node-RED flow with a voice command. The best solution I found so far is the emulated hue brigde from HA.

So, the hole thing is:
  • create an input boolean helper in HA
  • expose the input boolean via the emulated hue to alexa as a “light switch”
  • create an alexa voice routine like “Alexa, do some cool things”, which only switches this “light” on
  • create a Node-RED flow which listens on an event from the input boolean and then does the cool things… :wink:

So, I think the emulated hue bridge can also be used with HomeKit, because I assume, that hue can be used with HomeKit and the Apple Watch, right?
Maybe, It’s worth a try.