diff --git a/client/src/main/scala/org/scalaexercises/evaluator/Decoders.scala b/client/src/main/scala/org/scalaexercises/evaluator/Decoders.scala
deleted file mode 100644
index b43093f0..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/Decoders.scala
+++ /dev/null
@@ -1,23 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator
-
-import io.circe._, io.circe.jawn._, io.circe.syntax._
-
-object Decoders {
-
-  implicit val decodeRangePosition: Decoder[RangePosition] =
-    Decoder.forProduct3("start", "point", "end")(RangePosition.apply)
-
-  implicit val decodeCompilationInfo: Decoder[CompilationInfo] =
-    Decoder.forProduct2("message", "pos")(CompilationInfo.apply)
-
-  implicit val decodeEvalResponse: Decoder[EvalResponse] =
-    Decoder.forProduct5("msg", "value", "valueType", "consoleOutput", "compilationInfos")(
-      EvalResponse.apply)
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorAPI.scala b/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorAPI.scala
deleted file mode 100644
index 4707e950..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorAPI.scala
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator
-
-import cats.free.Free
-import org.scalaexercises.evaluator.EvaluatorResponses.EvaluationResponse
-import org.scalaexercises.evaluator.free.algebra.EvaluatorOps
-
-class EvaluatorAPI[F[_]](url: String, authKey: String)(implicit O: EvaluatorOps[F]) {
-
-  def evaluates(
-      resolvers: List[String] = Nil,
-      dependencies: List[Dependency] = Nil,
-      code: String): Free[F, EvaluationResponse[EvalResponse]] =
-    O.evaluates(url, authKey, resolvers, dependencies, code)
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorClient.scala b/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorClient.scala
index 69433b40..3b0ec3a7 100644
--- a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorClient.scala
+++ b/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorClient.scala
@@ -7,38 +7,19 @@
 
 package org.scalaexercises.evaluator
 
-import cats.data.EitherT
-import cats.~>
-import cats.implicits._
-import org.scalaexercises.evaluator.EvaluatorResponses.{
-  EvalIO,
-  EvaluationException,
-  EvaluationResponse,
-  EvaluationResult
-}
-import org.scalaexercises.evaluator.free.algebra.EvaluatorOp
-
-import scala.concurrent.Future
-import scala.concurrent.ExecutionContext.Implicits.global
+import cats.effect.{ConcurrentEffect, Resource}
+import org.http4s.client.Client
+import org.http4s.client.blaze.BlazeClientBuilder
+import org.scalaexercises.evaluator.service.{HttpClientHandler, HttpClientService}
 
-class EvaluatorClient(url: String, authKey: String) {
-
-  lazy val api: EvaluatorAPI[EvaluatorOp] = new EvaluatorAPI(url, authKey)
-
-}
+import scala.concurrent.ExecutionContext
 
 object EvaluatorClient {
 
-  def apply(url: String, authKey: String) =
-    new EvaluatorClient(url, authKey)
-
-  implicit class EvaluationIOSyntaxEither[A](evalIO: EvalIO[EvaluationResponse[A]]) {
-
-    def exec(implicit I: (EvaluatorOp ~> Future)): Future[EvaluationResponse[A]] =
-      evalIO foldMap I
+  private def clientResource[F[_]: ConcurrentEffect]: Resource[F, Client[F]] =
+    BlazeClientBuilder[F](ExecutionContext.global).resource
 
-    def liftEvaluator: EitherT[EvalIO, EvaluationException, EvaluationResult[A]] =
-      EitherT[EvalIO, EvaluationException, EvaluationResult[A]](evalIO)
+  def apply[F[_]: ConcurrentEffect](url: String, authKey: String): HttpClientService[F] =
+    HttpClientHandler[F](url, authKey, clientResource[F])
 
-  }
 }
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorResponses.scala b/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorResponses.scala
deleted file mode 100644
index c4dfe52d..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/EvaluatorResponses.scala
+++ /dev/null
@@ -1,62 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator
-
-import cats.free.Free
-import cats.implicits._
-import io.circe.Decoder
-import io.circe.parser._
-import org.scalaexercises.evaluator.free.algebra.EvaluatorOp
-
-import scala.concurrent.Future
-import scala.concurrent.ExecutionContext.Implicits.global
-import fr.hmil.roshttp.response.SimpleHttpResponse
-import fr.hmil.roshttp.util.HeaderMap
-
-object EvaluatorResponses {
-
-  type EvalIO[A] = Free[EvaluatorOp, A]
-
-  type EvaluationResponse[A] = Either[EvaluationException, EvaluationResult[A]]
-
-  case class EvaluationResult[A](result: A, statusCode: Int, headers: Map[String, String])
-
-  sealed abstract class EvaluationException(msg: String, cause: Option[Throwable] = None)
-      extends Throwable(msg) {
-    cause foreach initCause
-  }
-
-  case class JsonParsingException(msg: String, json: String) extends EvaluationException(msg)
-
-  case class UnexpectedException(msg: String) extends EvaluationException(msg)
-
-  def toEntity[A](futureResponse: Future[SimpleHttpResponse])(
-      implicit D: Decoder[A]): Future[EvaluationResponse[A]] =
-    futureResponse map {
-      case r if isSuccess(r.statusCode) ⇒
-        decode[A](r.body) match {
-          case Left(e) =>
-            Either.left(JsonParsingException(e.getMessage, r.body))
-          case Right(result) =>
-            Either.right(EvaluationResult(result, r.statusCode, r.headers.toLowerCase))
-        }
-      case r ⇒
-        Either.left(
-          UnexpectedException(
-            s"Failed i(nvoking get with status : ${r.statusCode}, body : \n ${r.body}"))
-    }
-
-  private[this] def isSuccess(statusCode: Int) =
-    statusCode >= 200 && statusCode <= 299
-
-  implicit class HeadersLowerCase[A >: String](headers: HeaderMap[A]) {
-
-    def toLowerCase: Map[String, A] =
-      headers.iterator.map(t => (t._1.toLowerCase, t._2)).toList.toMap
-  }
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/api/Evaluator.scala b/client/src/main/scala/org/scalaexercises/evaluator/api/Evaluator.scala
deleted file mode 100644
index 3d0c4bc8..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/api/Evaluator.scala
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator.api
-
-import io.circe.generic.auto._
-import io.circe.syntax._
-import org.scalaexercises.evaluator.EvaluatorResponses.EvaluationResponse
-import org.scalaexercises.evaluator.http.HttpClient
-import org.scalaexercises.evaluator.{Decoders, Dependency, EvalRequest, EvalResponse}
-
-import scala.concurrent.Future
-
-class Evaluator {
-
-  import Decoders._
-
-  private val httpClient = new HttpClient
-
-  def eval(
-      url: String,
-      authKey: String,
-      resolvers: List[String] = Nil,
-      dependencies: List[Dependency] = Nil,
-      code: String): Future[EvaluationResponse[EvalResponse]] =
-    httpClient.post[EvalResponse](
-      url = url,
-      secretKey = authKey,
-      data = EvalRequest(resolvers, dependencies, code).asJson.noSpaces)
-
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/free/algebra/EvaluatorOps.scala b/client/src/main/scala/org/scalaexercises/evaluator/free/algebra/EvaluatorOps.scala
deleted file mode 100644
index c18022af..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/free/algebra/EvaluatorOps.scala
+++ /dev/null
@@ -1,41 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator.free.algebra
-
-import cats.free.{Free, Inject}
-import org.scalaexercises.evaluator.EvaluatorResponses.EvaluationResponse
-import org.scalaexercises.evaluator.{Dependency, EvalResponse}
-
-sealed trait EvaluatorOp[A]
-final case class Evaluates(
-    url: String,
-    authKey: String,
-    resolvers: List[String] = Nil,
-    dependencies: List[Dependency] = Nil,
-    code: String)
-    extends EvaluatorOp[EvaluationResponse[EvalResponse]]
-
-class EvaluatorOps[F[_]](implicit I: Inject[EvaluatorOp, F]) {
-
-  def evaluates(
-      url: String,
-      authKey: String,
-      resolvers: List[String] = Nil,
-      dependencies: List[Dependency] = Nil,
-      code: String
-  ): Free[F, EvaluationResponse[EvalResponse]] =
-    Free.inject[EvaluatorOp, F](Evaluates(url, authKey, resolvers, dependencies, code))
-
-}
-
-object EvaluatorOps {
-
-  implicit def instance[F[_]](implicit I: Inject[EvaluatorOp, F]): EvaluatorOps[F] =
-    new EvaluatorOps[F]
-
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/free/interpreters/Interpreter.scala b/client/src/main/scala/org/scalaexercises/evaluator/free/interpreters/Interpreter.scala
deleted file mode 100644
index a8928cfc..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/free/interpreters/Interpreter.scala
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator.free.interpreters
-
-import cats.~>
-import org.scalaexercises.evaluator.api.Evaluator
-import org.scalaexercises.evaluator.free.algebra.{Evaluates, EvaluatorOp}
-
-import scala.concurrent.Future
-
-trait Interpreter {
-
-  /**
-   * Lifts Evaluator Ops to an effect capturing Monad such as Task via natural transformations
-   */
-  implicit def evaluatorOpsInterpreter: EvaluatorOp ~> Future =
-    new (EvaluatorOp ~> Future) {
-
-      val evaluator = new Evaluator()
-
-      def apply[A](fa: EvaluatorOp[A]): Future[A] = fa match {
-        case Evaluates(url, authKey, resolvers, dependencies, code) ⇒
-          evaluator.eval(url, authKey, resolvers, dependencies, code)
-      }
-
-    }
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/http/HttpClient.scala b/client/src/main/scala/org/scalaexercises/evaluator/http/HttpClient.scala
deleted file mode 100644
index 89d73905..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/http/HttpClient.scala
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator.http
-
-import io.circe.Decoder
-import org.scalaexercises.evaluator.EvaluatorResponses
-import org.scalaexercises.evaluator.EvaluatorResponses.EvaluationResponse
-
-import scala.concurrent.Future
-
-object HttpClient {
-
-  val authHeaderName = "x-scala-eval-api-token"
-  type Headers = Map[String, String]
-
-}
-
-class HttpClient {
-
-  import HttpClient._
-  def post[A](
-      url: String,
-      secretKey: String,
-      method: String = "post",
-      headers: Headers = Map.empty,
-      data: String
-  )(implicit D: Decoder[A]): Future[EvaluationResponse[A]] =
-    EvaluatorResponses.toEntity(
-      HttpRequestBuilder(url = url, httpVerb = method)
-        .withHeaders(headers + (authHeaderName -> secretKey))
-        .withBody(data)
-        .run)
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/http/HttpRequestBuilder.scala b/client/src/main/scala/org/scalaexercises/evaluator/http/HttpRequestBuilder.scala
deleted file mode 100644
index 69ac6a49..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/http/HttpRequestBuilder.scala
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator.http
-
-import org.scalaexercises.evaluator.http.HttpClient._
-
-import scala.concurrent.Future
-import fr.hmil.roshttp.{HttpRequest, Method}
-import fr.hmil.roshttp.body.BulkBodyPart
-import fr.hmil.roshttp.response.SimpleHttpResponse
-import java.nio.ByteBuffer
-
-import monix.execution.Scheduler.Implicits.global
-
-case class HttpRequestBuilder(
-    url: String,
-    httpVerb: String,
-    headers: Headers = Map.empty[String, String],
-    body: String = ""
-) {
-
-  case class CirceJSONBody(value: String) extends BulkBodyPart {
-    override def contentType: String = s"application/json; charset=utf-8"
-    override def contentData: ByteBuffer =
-      ByteBuffer.wrap(value.getBytes("utf-8"))
-  }
-
-  def withHeaders(headers: Headers) = copy(headers = headers)
-
-  def withBody(body: String) = copy(body = body)
-
-  def run: Future[SimpleHttpResponse] = {
-
-    val request = HttpRequest(url)
-      .withMethod(Method(httpVerb))
-      .withHeader("content-type", "application/json")
-      .withHeaders(headers.toList: _*)
-
-    request.send(CirceJSONBody(body))
-  }
-}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/implicits.scala b/client/src/main/scala/org/scalaexercises/evaluator/implicits.scala
deleted file mode 100644
index 3fa354e9..00000000
--- a/client/src/main/scala/org/scalaexercises/evaluator/implicits.scala
+++ /dev/null
@@ -1,12 +0,0 @@
-/*
- *
- *  scala-exercises - evaluator-client
- *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
- *
- */
-
-package org.scalaexercises.evaluator
-
-import org.scalaexercises.evaluator.free.interpreters.Interpreter
-
-object implicits extends Interpreter
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientHandler.scala b/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientHandler.scala
new file mode 100644
index 00000000..2f0c1bbb
--- /dev/null
+++ b/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientHandler.scala
@@ -0,0 +1,35 @@
+/*
+ *
+ *  scala-exercises - evaluator-client
+ *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
+ *
+ */
+
+package org.scalaexercises.evaluator.service
+import cats.effect.{Resource, Sync}
+import cats.implicits._
+import org.http4s.client.Client
+import org.http4s.{Header, Method, Request, Uri}
+import org.scalaexercises.evaluator._
+import org.scalaexercises.evaluator.util.Codecs._
+
+object HttpClientHandler {
+
+  private def headerToken(value: String) = Header("x-scala-eval-api-token", value)
+
+  private val headerContentType = Header("content-type", "application/json")
+
+  def apply[F[_]](uri: String, authString: String, resource: Resource[F, Client[F]])(
+      implicit F: Sync[F]): HttpClientService[F] =
+    new HttpClientService[F] {
+      override def evaluates(evalRequest: EvalRequest): F[EvalResponse] =
+        for {
+          uri <- F.fromEither(Uri.fromString(uri))
+          request = Request[F](Method.POST, uri)
+            .withEntity(evalRequest)
+            .withHeaders(headerToken(authString), headerContentType)
+          result <- resource.use(_.expect[EvalResponse](request))
+        } yield result
+    }
+
+}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientService.scala b/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientService.scala
new file mode 100644
index 00000000..562e71bb
--- /dev/null
+++ b/client/src/main/scala/org/scalaexercises/evaluator/service/HttpClientService.scala
@@ -0,0 +1,16 @@
+/*
+ *
+ *  scala-exercises - evaluator-client
+ *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
+ *
+ */
+
+package org.scalaexercises.evaluator.service
+
+import org.scalaexercises.evaluator.{EvalRequest, EvalResponse}
+
+trait HttpClientService[F[_]] {
+
+  def evaluates(evalRequest: EvalRequest): F[EvalResponse]
+
+}
diff --git a/client/src/main/scala/org/scalaexercises/evaluator/util/Codecs.scala b/client/src/main/scala/org/scalaexercises/evaluator/util/Codecs.scala
new file mode 100644
index 00000000..0a14a99f
--- /dev/null
+++ b/client/src/main/scala/org/scalaexercises/evaluator/util/Codecs.scala
@@ -0,0 +1,50 @@
+/*
+ *
+ *  scala-exercises - evaluator-client
+ *  Copyright (C) 2015-2019 47 Degrees, LLC. <http://www.47deg.com>
+ *
+ */
+
+package org.scalaexercises.evaluator.util
+
+import cats.effect.Sync
+import io.circe.generic.semiauto
+import io.circe.generic.semiauto.deriveDecoder
+import io.circe.syntax.EncoderOps
+import io.circe.{Decoder, Encoder, Json}
+import org.http4s.circe._
+import org.http4s.{EntityDecoder, EntityEncoder}
+import org.scalaexercises.evaluator._
+
+object Codecs {
+
+  implicit val decodeRangePosition: Decoder[RangePosition] = deriveDecoder[RangePosition]
+
+  implicit val decodeCompilationInfo: Decoder[CompilationInfo] = deriveDecoder[CompilationInfo]
+
+  implicit val decodeEvalResponse: Decoder[EvalResponse] = deriveDecoder[EvalResponse]
+
+  implicit val encodeEvalRequest: Encoder[EvalRequest] = Encoder.instance(
+    req =>
+      Json.obj(
+        ("resolvers", Json.arr(req.resolvers.map(Json.fromString): _*)),
+        ("dependencies", Json.arr(req.dependencies.map(_.asJson): _*)),
+        ("code", Json.fromString(req.code))
+    ))
+
+  implicit val encodeDependency: Encoder[Dependency] = Encoder.instance(
+    dep =>
+      Json.obj(
+        ("groupId", Json.fromString(dep.groupId)),
+        ("artifactId", Json.fromString(dep.artifactId)),
+        ("version", Json.fromString(dep.version)),
+        ("exclusions", dep.exclusions.asJson)
+    ))
+
+  implicit val encodeExclusion: Encoder[Exclusion] = semiauto.deriveEncoder[Exclusion]
+
+  implicit def decoder[F[_]: Sync, A: Decoder]: EntityDecoder[F, A] = jsonOf[F, A]
+
+  implicit def encoder[F[_]: Sync, A: Encoder]: EntityEncoder[F, A] = jsonEncoderOf[F, A]
+
+}