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.