Do rules for Magewrights exist in an unearthed arcana article?

I have been listening to Keith Baker on an episode of Todd Talks, where he discusses magewrights.

Unless I’m mistaken, he mentioned that the rules for magewrights exist outside of the core Eberron book, possibly in an unearthed arcana.

As I’m interested in using magewrights outside of Eberron, I would like to know if the rules are in an unearthed arcana before deciding if I want to purchase the actual book.