Pact JVM is currently compliant to Pact Specification Version 2.0, and implements some non-standard features coming in 3.0.
Head to the JVM website to get started with Pact on the JVM (Java, Scala, Clojure etc.).
For a Scala specific implementation, there is Scala-Pact from the folks at ITV. This is Pact Specification Version 2.0 compliant and supports SBT and ScalaTest.
This workshop walks you through an example problem from start to finish, exploring most concepts that Pact supports. It takes approximately 2 hours to complete.