Just add the following to your libraryDependencies in SBT:

libraryDependencies += "com.pepegar" %% "hammock" % "0.7.1" // for JVM
libraryDependencies += "com.pepegar" %%% "hammock" % "0.7.1" // for JS


There are already some companion modules implemented to ease the experience of using hammock.

libraryDependencies += "com.pepegar" %% "hammock-circe" % "0.7.1" // for JVM
libraryDependencies += "com.pepegar" %%% "hammock-circe" % "0.7.1" // for JS
libraryDependencies += "com.pepegar" %% "hammock-akka-http" % "0.7.1" // only for JVM

Functional programming

Hammock tries to be as functional as possible. For example, the environment in wich all the actions will be executed is called Monad, but fear not! Lots of types you were using before are already monads, you know how to use them!


Module name Description Version
hammock-core the core functionality of hammock, using Apache HTTP commons for HTTP in JVM and XHR in JS 0.7.1
hammock-circe encode and decode HTTP entities with Circe 0.7.1
hammock-akka-http run your HTTP requests with akka-http 0.7.1


With Hammock you can do HTTP operations in a typeful and functional way.

import cats.effect.IO
import io.circe._
import hammock._
import hammock.Uri._
import hammock.hi._
import hammock.circe.implicits._

object HttpClient {
  implicit val interp = Interpreter[IO]
  val response = Hammock
    .getWithOpts(Uri.unsafeParse(""), Opts.default)
scala> HttpClient.response.unsafeRunSync
res2: List[String] = List(0cdc651e, 42286d75, 4f97a2e9, 54bf6aa9, 61b4b03d, 61fc54d5, 94c3cd60, dd69cf53, fc6de645)

Target Monad

Hammock uses cats-effect’s Sync under the hood to provide a safe way of capturing effects when interpreting your programs.

You can use as a target monad any type F that has an instance of Sync. There are already several types you can use out of the box, for example:

  • cats.effect.IO: An IO type for the cats ecosystem.
  • scala.concurrent.Future: There are lots of applications out there that express their IO effects with Future, you can still use it!
  • scala.util.Try: You don’t care of blocking current thread? go ahead, use it!
  • monix/Task: Great implementation of a concurrency monad. You can learn more about it here