Seems it's using Esprit (https://github.com/mfikes/esprit https://github.com/mfikes/esprit) which is using Espruino (https://www.espruino.com/ https://www.espru

Seems it's using Esprit (https://github.com/mfikes/esprit https://github.com/mfikes/esprit) which is using Espruino (https://www.espruino.com/ https://www.espruino.com/) who in their reference documentation for the API (https://www.espruino.com/Reference https://www.espruino.com/Reference) lists methods for both Bluetooth and I2C. (The submitted project is with ClojureScript that compiles to JavaScript, not Clojure, to be extra specific in case someone misses the difference)