The vast majority of ceiling fans aren’t wired that way. There’s a single source of electricity, almost always connected to a wall switch that sends power up to the canopy where it’s separated into the fan speed control and the light circuit. (That’s also why most ceiling fans have two pull switches, one for fan speed and one for lights. They come in after the load line is split.)
Some manufacturers are recognizing that people want wall-mounted control of both, especially when the fan may be up some distance on a high ceiling. They’re doing two things: 1) providing a wall mount that holds a remote control or 2) splitting the wiring at the switch and providing the control down there. In the former case, you’re back to where most people go with a canopy-based set of smart controllers. In the later case, you can relatively easily replace the provided controls with smart controls, but you might have to expand the box to allow two full-sized controls. If that last bit is the case, unless you’re really electrically savvy and living in a location that allows Do-It-Yourself electrical work, you’ll need an electrician to do it right. (They can also sign paperwork that says everything is up to local code, which is important when selling the house at least).
Also, it’s a good idea to look through the Wiki to see if some aspects of your project have already been addressed. For instance, https://community.smartthings.com/t/automating-fan-control-dont-use-a-light-dimmer/18332