Solex CC is an on-vehicle software development kit written in Node JS that lets you write scripts called "workers" to interact with your vehicle, the Solex app (or your own GCS app), and external devices attached to your vehicle in any way you see fit. Control LEDs, sensors, actuators and more, and even customize the Solex UI from your scripts.
Read an intro to the Solex CC SDK, and see if it's a fit for your application.
A big collection of example workers showing what Solex CC can do.
Clone the Solex CC repo to your local machine to get started!