sttp: the Scala HTTP client you always wanted!


sttp client is an open-source library which provides a clean, programmer-friendly API to describe HTTP requests and how to handle responses. Requests are sent using one of the backends, which wrap other Scala or Java HTTP client implementations. The backends can integrate with a variety of Scala stacks, providing both synchronous and asynchronous, procedural and functional interfaces.

Backend implementations include ones based on akka-http, async-http-client, http4s, OkHttp, and HTTP clients which ship with Java. They integrate with Akka, Monix, fs2, cats-effect, scalaz and ZIO.

Here’s a quick example of sttp client in action:

import sttp.client3._

val query = "http language:scala"
val sort: Option[String] = None

// the `query` parameter is automatically url-encoded
// `sort` is removed, as the value is not defined
val request = basicRequest.get(

val backend = HttpURLConnectionBackend()
val response = request.send(backend)

// response.header(...): Option[String]

// response.body: by default read into an Either[String, String] 
// to indicate failure or success 

// alternatively, if you prefer to pass the backend explicitly, instead
// of using implicits, you can also call:
val sameResponse = backend.send(request)

For more examples, see the usage examples section. To start using sttp client in your project, see the quickstart. Or, browse the documentation to find the topics that interest you the most!

Other sttp projects

sttp is a family of Scala HTTP-related projects, and currently includes:

  • sttp client: this project
  • sttp tapir: Typed API descRiptions
  • sttp model: simple HTTP model classes (used by client & tapir)
  • sttp shared: shared web socket, FP abstractions, capabilities and streaming code.


Development and maintenance of sttp client is sponsored by SoftwareMill, a software development and consulting company. We help clients scale their business through software. Our areas of expertise include backends, distributed systems, blockchain, machine learning and data analytics.


Try sttp client in your browser!

Table of contents

More information