This really needs a demo: punch in a name, select model, get response on the website itself. Using curl to send a post request is not a high bar, but for lazy readers on mobile (like me) it's still too much.

I actually would have use for this software, as I deal with clients from all over the world and sometimes have no clue if they're a man or a woman. So far I've been looking up the names on Wikipedia.

No. This is a bad concept for a product. There is no situation where your business should be guessing people's genders at-scale: it is a recipe for getting things wrong in a way you will find embarrassing later on. If it matters, just ask.