The akka-http-jackson framework generates the same server and client APIs as the akka-http framework, except that Jackson is used for serialization and deserialization (instead of Circe).

Usage-wise, it is very similar to akka-http. Extra information specific to this framework can be found below.

guardrail Configuration

You can either specify the akka-http-jackson framework, or the akka-http and jackson modules.


In addition to the akka-http dependencies, you’ll need the following:

  • com.fasterxml.jackson.core:jackson-core
  • com.fasterxml.jackson.core:jackson-databind
  • com.fasterxml.jackson.core:jackson-annotations
  • com.fasterxml.jackson.datatype:jackson-datatype-jsr310 (only if date and date-time types are used in your spec)
  • com.fasterxml.jackson.module:jackson-module-scala_${scala.compat.version}
  • org.hibernate.validator:hibernate-validator (or org.hibernate:hibernate-validator)

While testing has been done with Jackson 2.11.x, older 2.x versions should work as well. Hibernate Validator 5.4.x and 6.0.x have been tested and appear to work.

Server and Client Construction

When constructing your server routes or client instances, you’ll need implicit ObjectMapper (Jackson) and Validator (Hibernate) instances available.


You must register DefaultScalaModule on your object mapper. If your spec uses date or date-time string formats, you must also register JavaTimeModule.


The validator can be constructed in whatever manner you desire. Hibernate is recommended, but guardrail does not currently use any Hibernate-specific annotations; however, it may do so in the future as more strict validations are implemented.


In general, using the Circe-backed akka-http is recommended if you have a choice. However, if you’re required to use Jackson for some reason, this framework is available. It’s also useful if you have a Scala project that needs protocol/model objects, and you need to use Jackson.