JSON

Adding support for JSON (or other format) bodies in requests/responses is a matter of providing a body serializer and/or a response body specification. Both are quite straightforward to implement, so integrating with your favorite JSON library shouldn’t be a problem. However, there are some integrations available out-of-the-box.

Circe

JSON encoding of bodies and decoding of responses can be handled using Circe by the circe module. To use add the following dependency to your project:

"com.softwaremill.sttp" %% "circe" % "1.1.14"

This module adds a method to the request and a function that can be given to a request to decode the response to a specific object:

import com.softwaremill.sttp._
import com.softwaremill.sttp.circe._

implicit val backend = HttpURLConnectionBackend()

// Assume that there is an implicit circe encoder in scope
// for the request Payload, and a decoder for the MyResponse
val requestPayload: Payload = ???

val response: Either[io.circe.Error, MyResponse] =
  sttp
    .post(uri"...")
    .body(requestPayload)
    .response(asJson[MyResponse])
    .send()

Json4s

To encode and decode json using json4s-native, add the following dependency to your project:

"com.softwaremill.sttp" %% "json4s" % "1.1.14"

Using this module it is possible to set request bodies and read response bodies as case classes, using the implicitly available org.json4s.Formats (which defaults to org.json4s.DefaultFormats).

Usage example:

import com.softwaremill.sttp._
import com.softwaremill.sttp.json4s._

implicit val backend = HttpURLConnectionBackend()

case class Payload(...)
case class MyResponse(...)

val requestPayload: Payload = Payload(...)

val response: Response[MyResponse] =
  sttp
    .post(uri"...")
    .body(requestPayload)
    .response(asJson[MyResponse])
    .send()