Lemmy Know (let me know) is a lightweight CLI application / Docker service that monitors Lemmy for reports on posts and comments and sends notification. These can be sent to a Discord channel with a webhook or as MQTT messages (schema), which is useful for more complex setups with e.g., Node-RED.
MQTT (aka MQ Telemetry Transport) is a machine-to-machine or “Internet of Things” connectivity protocol on top of TCP/IP. It allows extremely lightweight publish/subscribe messaging transport.
Frankly, this should be implemented with something like a combination of:
https://github.com/QazCetelic/lemmy-know
https://www.home-assistant.io/
https://www.home-assistant.io/integrations/mqtt/
https://github.com/DevelopmentalOctopus/ha-buttplug
https://intiface.com/central/
Some collection of hardware devices from:
https://iostindex.com/?filter0Availability=Available,DIY&filter1Connection=Digital&filter2ButtplugSupport=4
That’d permit for, say, having message events drive a state machine to control devices or something like that.