For XML Akka HTTP currently provides support for Scala XML right out of the box through it's akka-http-xml module.
Scala XML Support
The ScalaXmlSupport trait provides a FromEntityUnmarshaller[NodeSeq] and ToEntityMarshaller[NodeSeq] that you can use directly or build upon.
This is how you enable support for (un)marshalling from and to JSON with Scala XML NodeSeq:
- Add a library dependency onto "com.typesafe.akka" %% "akka-http-xml-experimental" % "1.x".
- import akka.http.scaladsl.marshallers.xml.ScalaXmlSupport._ or mix in the akka.http.scaladsl.marshallers.xml.ScalaXmlSupport trait.
Once you have done this (un)marshalling between XML and NodeSeq instances should work nicely and transparently.