Adafruit IO has a very customer-friendly model where you own your data and the client libraries are open source. https://io.adafruit.com/ https://io.adafruit.co

Adafruit IO has a very customer-friendly model where you own your data and the client libraries are open source. https://io.adafruit.com/ https://io.adafruit.com/ Not all of the server features are open source, but there is an API-compatible version here that should let you self-host if you want. https://github.com/adafruit/adafruit-io-node https://github.com/adafruit/adafruit-io-node