I'd say you're on the right track, then! It's kind of like software — figure out how the components talk to each other and figure out where to hook in. Instead of APIs, you've got multimeters and oscilloscopes.
In the case of the blind automation, the remote uses some kind of proprietary wireless signal. Instead of figuring that out, I soldered some leads into the remote's momentary button terminals, which I connected to transistors on a breadboard. The ESP32 simply pretends to press a button and complete a connection on the remote.
Also check out ESPHome (https://esphome.io), a firmware for ESP32 that lets you more easily integrate with home automation systems.
In the case of the blind automation, the remote uses some kind of proprietary wireless signal. Instead of figuring that out, I soldered some leads into the remote's momentary button terminals, which I connected to transistors on a breadboard. The ESP32 simply pretends to press a button and complete a connection on the remote.
Also check out ESPHome (https://esphome.io), a firmware for ESP32 that lets you more easily integrate with home automation systems.