It’s still an interface
Before you adopt the strategy of building a product without any kind of user interface, realise that you have made how to use your product completely opaque.
We have spent the last 30+ years educating users on how to interact with computers through easily discoverable user interfaces.
I see a lot of start-ups now proposing we get rid of that paradigm.
I applaud you for trying new things, but “no user interface” is still a “user interface.”
And user interfaces are like jokes. If you have to explain it, it’s probably not very good.