If you’re not already bought-in to using OpenAPI-generated clients, I wouldn’t recommend starting with this. I tried to use this a few months ago, and quite frankly the quality of the SDK it generated was pretty bad. There were some notable issues with the templates (I can’t remember exactly, but things like it wouldn’t even compile with certain configurations), and the fact that it generates an entire Gradle project rather than just the source code is really annoying (can’t really fit into CI for with app). Plus, there’s no way to customize the Ktor HttpEngine at runtime (among many other annoyances)
I think if they could set it up to use something like KotlinPoet instead of Handlebars templates, the quality of generated code would be better, but overall it wasn’t a very pleasant experience for me. It might be worth it if you have a large API with perfectly-documented endpoints, otherwise I’d say it’s not worth it. It doesn’t do that much more than what you’d do by hand with Ktor, and I think you’ll find it to be much more flexible and usable to just do it yourself