kantan.xpath has a cats module that is, in its current incarnation, fairly bare bones: it provides a few useful type class instances.
The cats module can be used by adding the following dependency to your build.sbt:
libraryDependencies += "com.nrinaudo" %% "kantan.xpath-cats" % "0.5.3"
You then need to import the corresponding package:
import kantan.xpath.cats._
The following instance for cats type classes are provided:
MonadError and SemigroupK for NodeDecoder.Contravariant for XmlSource.Show and Eq for all error types (XPathError and all its descendants).Show for Node.