diff --git a/build.sbt b/build.sbt
index 486e95f0..5b2f23a8 100644
--- a/build.sbt
+++ b/build.sbt
@@ -34,20 +34,33 @@ lazy val root =
   project
     .in(file("."))
     .aggregate(
+      core.js,
+      core.jvm,
       lambda.js,
       lambda.jvm,
       lambdaEvents.js,
       lambdaEvents.jvm,
       lambdaApiGatewayProxyHttp4s.js,
-      lambdaApiGatewayProxyHttp4s.jvm)
+      lambdaApiGatewayProxyHttp4s.jvm,
+      cloudflareWorker
+    )
     .enablePlugins(NoPublishPlugin)
 
+lazy val core = crossProject(JSPlatform, JVMPlatform)
+  .crossType(CrossType.Pure)
+  .in(file("core"))
+  .settings(
+    name := "feral-core",
+    libraryDependencies ++= Seq(
+      "org.typelevel" %%% "cats-effect" % catsEffectVersion,
+    )
+  )
+
 lazy val lambda = crossProject(JSPlatform, JVMPlatform)
   .in(file("lambda"))
   .settings(
     name := "feral-lambda",
     libraryDependencies ++= Seq(
-      "org.typelevel" %%% "cats-effect" % catsEffectVersion,
       "io.circe" %%% "circe-core" % circeVersion
     )
   )
@@ -63,6 +76,7 @@ lazy val lambda = crossProject(JSPlatform, JVMPlatform)
       "io.circe" %%% "circe-fs2" % "0.14.0"
     )
   )
+  .dependsOn(core)
 
 lazy val lambdaEvents = crossProject(JSPlatform, JVMPlatform)
   .crossType(CrossType.Pure)
@@ -84,3 +98,18 @@ lazy val lambdaApiGatewayProxyHttp4s = crossProject(JSPlatform, JVMPlatform)
     )
   )
   .dependsOn(lambda, lambdaEvents)
+
+lazy val cloudflareWorker = project
+  .in(file("cloudflare-worker"))
+  .enablePlugins(ScalaJSPlugin)
+  .settings(
+    name := "feral-cloudflare-worker",
+    libraryDependencies ++= Seq(
+      "org.typelevel" %%% "cats-effect" % catsEffectVersion,
+      "co.fs2" %%% "fs2-core" % fs2Version,
+      "io.circe" %%% "circe-generic" % circeVersion,
+      "io.circe" %%% "circe-scalajs" % circeVersion,
+      "org.http4s" %%% "http4s-client" % http4sVersion
+    )
+  ).dependsOn(core.js)
+  
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/FetchEventListener.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/FetchEventListener.scala
new file mode 100644
index 00000000..f9a11844
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/FetchEventListener.scala
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral
+package cloudflare.worker
+
+import cats.effect.IO
+import cats.effect.SyncIO
+import cats.effect.kernel.Resource
+import cats.effect.std.Supervisor
+import io.circe.Decoder
+import io.circe.Json
+import io.circe.generic.semiauto._
+import io.circe.scalajs._
+import org.http4s.HttpRoutes
+import org.http4s.Request
+import org.typelevel.vault.Key
+import org.http4s.HttpVersion
+
+trait FetchEventListener extends IOSetup {
+
+  def routes: Resource[IO, HttpRoutes[IO]]
+
+  final type Setup = HttpRoutes[IO]
+  protected override final val setup = routes
+
+  private def apply(event: facade.FetchEvent): Unit =
+    event.waitUntil(
+      Supervisor[IO]
+        .use { supervisor =>
+          for {
+            routes <- setupMemo
+            request <- fromRequest[IO](event.request)
+            properties <- IO.fromEither(decodeJs[IncomingRequestCfProperties](event.request.cf))
+            httpVersion <- IO.fromEither(HttpVersion.fromString(properties.httpProtocol))
+            _ <- routes(request
+              .withHttpVersion(httpVersion)
+              .withAttribute(FetchEventContext.key, FetchEventContext(supervisor, properties)))
+              .map(toResponse[IO])
+              .foldF(IO.unit)(r => IO(event.respondWith(r)))
+          } yield ()
+        }
+        .unsafeToPromise()(runtime))
+
+  final def main(args: Array[String]): Unit =
+    addEventListener[facade.FetchEvent]("fetch", apply)
+
+}
+
+final case class FetchEventContext(
+    supervisor: Supervisor[IO],
+    properties: IncomingRequestCfProperties)
+
+object FetchEventContext {
+  private[worker] val key = Key.newKey[SyncIO, FetchEventContext].unsafeRunSync()
+  def apply(request: Request[IO]): IO[FetchEventContext] =
+    IO.fromEither(request.attributes.lookup(key).toRight(new NoSuchElementException))
+}
+
+final case class IncomingRequestCfProperties(
+    asn: String,
+    colo: String,
+    country: Option[String],
+    httpProtocol: String,
+    requestPriority: Option[String],
+    tlsCipher: String,
+    tlsClientAuth: Option[Json],
+    tlsVersion: String,
+    city: Option[String],
+    continent: Option[String],
+    latitude: Option[String],
+    longitude: Option[String],
+    postalCode: Option[String],
+    metroCode: Option[String],
+    region: Option[String],
+    regionCode: Option[String],
+    timezone: String
+)
+
+object IncomingRequestCfProperties {
+  private[worker] implicit def decoder: Decoder[IncomingRequestCfProperties] = deriveDecoder
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/KVNamespace.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/KVNamespace.scala
new file mode 100644
index 00000000..38416a0a
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/KVNamespace.scala
@@ -0,0 +1,276 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker
+
+import scala.scalajs.js
+import scala.scalajs.js.JSConverters._
+import scala.concurrent.duration.FiniteDuration
+import io.circe.Decoder
+
+import fs2.Stream
+import scodec.bits.ByteVector
+import io.circe.Encoder
+import io.circe.scalajs._
+import cats.effect.kernel.Async
+import cats.syntax.all._
+import cats.data.OptionT
+import fs2.Chunk
+import cats.effect.kernel.Resource
+
+sealed trait KVNamespace[F[_]] {
+
+  import KVNamespace._
+
+  def getText(key: String): F[Option[String]]
+  def getText(key: String, cacheTtl: FiniteDuration): F[Option[String]]
+
+  def get[A: Decoder](key: String): F[Option[A]]
+  def get[A: Decoder](key: String, cacheTtl: FiniteDuration): F[Option[A]]
+
+  def getByteVector(key: String): F[Option[ByteVector]]
+  def getByteVector(key: String, cacheTtl: FiniteDuration): F[Option[ByteVector]]
+
+  def getStream(key: String): Resource[F, Option[Stream[F, Byte]]]
+  def getStream(key: String, cacheTtl: FiniteDuration): Resource[F, Option[Stream[F, Byte]]]
+
+  def getTextWithMetadata[M: Decoder](key: String): F[Option[(String, Option[M])]]
+
+  def getWithMetadata[A: Decoder, M: Decoder](key: String): F[Option[(A, Option[M])]]
+
+  def getByteVectorWithMetadata[M: Decoder](key: String): F[Option[(ByteVector, Option[M])]]
+
+  def getStreamWithMetadata[M: Decoder](
+      key: String): Resource[F, Option[(Stream[F, Byte], Option[M])]]
+
+  def put(key: String, value: String): F[Unit] = put[Unit](key, value, PutOptions())
+  def put[M: Encoder](key: String, value: String, options: PutOptions[M]): F[Unit]
+
+  def put[A: Encoder](key: String, value: A): F[Unit] = put[A, Unit](key, value, PutOptions())
+  def put[A: Encoder, M: Encoder](key: String, value: A, options: PutOptions[M]): F[Unit] =
+    put(key, Encoder[A].apply(value).noSpaces, options)
+
+  def put(key: String, value: ByteVector): F[Unit] = put[Unit](key, value, PutOptions())
+  def put[M: Encoder](key: String, value: ByteVector, options: PutOptions[M]): F[Unit]
+
+  def put(key: String, value: Stream[F, Byte]): F[Unit] = put[Unit](key, value, PutOptions())
+  def put[M: Encoder](key: String, value: Stream[F, Byte], options: PutOptions[M]): F[Unit]
+
+  def delete(key: String): F[Unit]
+
+  def list[M: Decoder]: Stream[F, Key[M]]
+  def list[M: Decoder](prefix: String): Stream[F, Key[M]]
+
+}
+
+object KVNamespace {
+
+  final case class Key[+M](name: String, expiration: Option[js.Date], metadata: Option[M])
+
+  final case class PutOptions[+M](
+      expiration: Option[js.Date] = None,
+      expirationTtl: Option[FiniteDuration] = None,
+      metadata: Option[M] = None
+  ) {
+    private[KVNamespace] def toJS[M0 >: M](implicit e: Encoder[M0]): facade.PutOptions =
+      facade.PutOptions(
+        expiration.map(_.getDate() / 1000).orUndefined,
+        expirationTtl.map(_.toSeconds.toDouble).orUndefined,
+        metadata.map((_: M0).asJsAny).orUndefined
+      )
+  }
+
+  def apply[F[_]: Async](namespace: String): KVNamespace[F] =
+    new AsyncKVNamespace[F](
+      js.special
+        .fileLevelThis
+        .asInstanceOf[js.Dynamic]
+        .selectDynamic(namespace)
+        .asInstanceOf[facade.KVNamespace])
+
+  private final class AsyncKVNamespace[F[_]](kv: facade.KVNamespace)(implicit F: Async[F])
+      extends KVNamespace[F] {
+
+    def getText(key: String): F[Option[String]] =
+      F.fromPromise(F.delay(kv.get(key, facade.GetOptions("text"))))
+        .map(x => Option(x.asInstanceOf[String]))
+
+    def getText(key: String, cacheTtl: FiniteDuration): F[Option[String]] =
+      F.fromPromise(
+        F.delay(kv.get(key, facade.GetOptions("text", cacheTtl.toSeconds.toDouble))))
+        .map(x => Option(x.asInstanceOf[String]))
+
+    def get[A: Decoder](key: String): F[Option[A]] =
+      OptionT(
+        F.fromPromise(F.delay(kv.get(key, facade.GetOptions("json"))))
+          .map(x => Option(x.asInstanceOf[js.Any]))
+      ).semiflatMap(x => F.fromEither(decodeJs[A](x))).value
+
+    def get[A: Decoder](key: String, cacheTtl: FiniteDuration): F[Option[A]] =
+      OptionT(
+        F.fromPromise(
+          F.delay(kv.get(key, facade.GetOptions("json", cacheTtl.toSeconds.toDouble))))
+          .map(x => Option(x.asInstanceOf[js.Any]))
+      ).semiflatMap(x => F.fromEither(decodeJs[A](x))).value
+
+    def getByteVector(key: String): F[Option[ByteVector]] =
+      OptionT(
+        F.fromPromise(F.delay(kv.get(key, facade.GetOptions("arrayBuffer"))))
+          .map(x => Option(x.asInstanceOf[js.typedarray.ArrayBuffer]))
+      ).map(Chunk.jsArrayBuffer(_).toByteVector).value
+
+    def getByteVector(key: String, cacheTtl: FiniteDuration): F[Option[ByteVector]] =
+      OptionT(
+        F.fromPromise(
+          F.delay(kv.get(key, facade.GetOptions("arrayBuffer", cacheTtl.toSeconds.toDouble))))
+          .map(x => Option(x.asInstanceOf[js.typedarray.ArrayBuffer]))
+      ).map(Chunk.jsArrayBuffer(_).toByteVector).value
+
+    def getStream(key: String): Resource[F, Option[Stream[F, Byte]]] =
+      OptionT(
+        Resource.makeCase(F
+          .fromPromise(F.delay(kv.get(key, facade.GetOptions("stream"))))
+          .map(x => Option(x.asInstanceOf[facade.ReadableStream[js.typedarray.Uint8Array]]))) {
+          case (Some(rs), exitCase) => closeReadableStream(rs, exitCase)
+          case _ => F.unit
+        }
+      ).map(fromReadableStream[F]).value
+
+    def getStream(key: String, cacheTtl: FiniteDuration): Resource[F, Option[Stream[F, Byte]]] =
+      OptionT(
+        Resource.makeCase(
+          F.fromPromise(
+            F.delay(kv.get(key, facade.GetOptions("stream", cacheTtl.toSeconds.toDouble))))
+            .map(x =>
+              Option(x.asInstanceOf[facade.ReadableStream[js.typedarray.Uint8Array]]))) {
+          case (Some(rs), exitCase) => closeReadableStream(rs, exitCase)
+          case _ => F.unit
+        }
+      ).map(fromReadableStream[F]).value
+
+    def getTextWithMetadata[M: Decoder](key: String): F[Option[(String, Option[M])]] =
+      F.fromPromise(
+        F.delay(kv.getWithMetadata(key, "text"))
+      ).flatMap { vm =>
+        OptionT
+          .fromOption(Option(vm.value.asInstanceOf[String]))
+          .semiflatMap { value =>
+            OptionT
+              .fromOption(Option(vm.metadata))
+              .semiflatMap(x => F.fromEither(decodeJs[M](x)))
+              .value
+              .map((value, _))
+          }
+          .value
+      }
+
+    def getWithMetadata[A: Decoder, M: Decoder](key: String): F[Option[(A, Option[M])]] =
+      F.fromPromise(
+        F.delay(kv.getWithMetadata(key, "json"))
+      ).flatMap { vm =>
+        OptionT
+          .fromOption(Option(vm.value.asInstanceOf[js.Any]))
+          .semiflatMap(x => F.fromEither(decodeJs[A](x)))
+          .semiflatMap { value =>
+            OptionT
+              .fromOption(Option(vm.metadata))
+              .semiflatMap(x => F.fromEither(decodeJs[M](x)))
+              .value
+              .map((value, _))
+          }
+          .value
+      }
+
+    def getByteVectorWithMetadata[M: Decoder](key: String): F[Option[(ByteVector, Option[M])]] =
+      F.fromPromise(
+        F.delay(kv.getWithMetadata(key, "arrayBuffer"))
+      ).flatMap { vm =>
+        OptionT
+          .fromOption(Option(vm.value.asInstanceOf[js.typedarray.ArrayBuffer]))
+          .semiflatMap { value =>
+            OptionT
+              .fromOption(Option(vm.metadata))
+              .semiflatMap(x => F.fromEither(decodeJs[M](x)))
+              .value
+              .map((Chunk.jsArrayBuffer(value).toByteVector, _))
+          }
+          .value
+      }
+
+    def getStreamWithMetadata[M: Decoder](
+        key: String): Resource[F, Option[(Stream[F, Byte], Option[M])]] =
+      OptionT(
+        Resource.makeCase(
+          F.fromPromise(
+            F.delay(kv.getWithMetadata(key, "stream"))
+          ).flatMap { vm =>
+            OptionT
+              .fromOption(
+                Option(vm.value.asInstanceOf[facade.ReadableStream[js.typedarray.Uint8Array]]))
+              .semiflatMap { value =>
+                OptionT
+                  .fromOption(Option(vm.metadata))
+                  .semiflatMap(x => F.fromEither(decodeJs[M](x)))
+                  .value
+                  .map((value, _))
+              }
+              .value
+          }) {
+          case (Some((rs, _)), exitCase) => closeReadableStream(rs, exitCase)
+          case _ => F.unit
+        }).map {
+        case (rs, m) =>
+          (fromReadableStream(rs), m)
+      }.value
+
+    def put[M: Encoder](key: String, value: String, options: PutOptions[M]): F[Unit] =
+      F.fromPromise(F.delay(kv.put(key, value, options.toJS[M])))
+
+    def put[M: Encoder](key: String, value: ByteVector, options: PutOptions[M]): F[Unit] =
+      F.fromPromise(
+        F.delay(kv.put(key, Chunk.byteVector(value).toJSArrayBuffer, options.toJS[M])))
+
+    def put[M: Encoder](key: String, value: Stream[F, Byte], options: PutOptions[M]): F[Unit] =
+      ???
+
+    def delete(key: String): F[Unit] = F.fromPromise(F.delay(kv.delete(key)))
+
+    def list[M: Decoder]: Stream[F, Key[M]] = list[M](js.undefined)
+
+    def list[M: Decoder](prefix: String): Stream[F, Key[M]] = list[M](prefix)
+
+    private def list[M: Decoder](prefix: js.UndefOr[String]): Stream[F, Key[M]] =
+      Stream
+        .unfoldLoopEval(js.undefined: js.UndefOr[String]) { cursor =>
+          F.fromPromise(F.delay(kv.list(facade.ListOptions(prefix = prefix, cursor = cursor))))
+            .map { response =>
+              (response.keys, if (!response.list_complete) Some(response.cursor) else None)
+            }
+        }
+        .flatMap { keys =>
+          Stream.emits(keys.toSeq).evalMap { key =>
+            OptionT
+              .fromOption[F](key.metadata.toOption.flatMap(Option(_)))
+              .semiflatMap(x => F.fromEither(decodeJs[M](x)))
+              .value
+              .map {
+                Key(key.name, key.expiration.toOption.flatMap(Option(_)).map(new js.Date(_)), _)
+              }
+          }
+        }
+  }
+
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEvent.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEvent.scala
new file mode 100644
index 00000000..89e01bc9
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEvent.scala
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker
+
+import scala.scalajs.js
+
+final case class ScheduledEvent(cron: String, scheduledTime: js.Date)
+
+object ScheduledEvent {
+  private[worker] def apply(event: facade.ScheduledEvent): ScheduledEvent =
+    ScheduledEvent(event.cron, new js.Date(event.scheduledTime))
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEventListener.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEventListener.scala
new file mode 100644
index 00000000..8e6de01e
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/ScheduledEventListener.scala
@@ -0,0 +1,33 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral
+package cloudflare.worker
+
+import cats.effect.IO
+
+trait ScheduledEventListener extends IOSetup {
+
+  def apply(event: ScheduledEvent, setup: Setup): IO[Unit]
+
+  final def main(args: Array[String]): Unit =
+    addEventListener[facade.ScheduledEvent](
+      "scheduled",
+      event =>
+        event.waitUntil(
+          setupMemo.flatMap(apply(ScheduledEvent(event), _)).unsafeToPromise()(runtime)))
+
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Event.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Event.scala
new file mode 100644
index 00000000..2a421941
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Event.scala
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker.facade
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+
+@js.native
+private[worker] trait Event extends js.Object {
+  @nowarn def waitUntil(promise: js.Promise[Unit]): Unit = js.native
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/FetchEvent.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/FetchEvent.scala
new file mode 100644
index 00000000..05a568ab
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/FetchEvent.scala
@@ -0,0 +1,26 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker.facade
+
+import scala.scalajs.js
+import scala.scalajs.js.|
+
+@js.native
+private[worker] sealed trait FetchEvent extends Event {
+  def request: Request = js.native
+  def respondWith(response: Response | js.Promise[Response]): Unit
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Headers.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Headers.scala
new file mode 100644
index 00000000..c9473a56
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Headers.scala
@@ -0,0 +1,16 @@
+package feral.cloudflare.worker.facade
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+import scala.scalajs.js.annotation.JSGlobal
+import scala.scalajs.js.annotation.JSName
+
+@js.native
+@JSGlobal
+@nowarn
+private[worker] class Headers(map: js.Dictionary[String])
+    extends js.Iterable[js.Array[String]] {
+
+  @JSName(js.Symbol.iterator)
+  def jsIterator(): js.Iterator[js.Array[String]] = js.native
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/KVNamespace.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/KVNamespace.scala
new file mode 100644
index 00000000..bd1b6b1e
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/KVNamespace.scala
@@ -0,0 +1,106 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker.facade
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+import scala.scalajs.js.|
+
+@js.native
+@nowarn
+private[worker] sealed trait KVNamespace extends js.Object {
+
+  def get(key: String, options: GetOptions): js.Promise[
+    String | js.Any | js.typedarray.ArrayBuffer | ReadableStream[js.typedarray.Uint8Array]]
+
+  def getWithMetadata(key: String, `type`: String): js.Promise[KVValueWithMetadata] = js.native
+
+  def put(
+      key: String,
+      value: String | ReadableStream[js.typedarray.Uint8Array] | js.typedarray.ArrayBuffer,
+      options: js.UndefOr[PutOptions] = js.native): js.Promise[Unit] = js.native
+
+  def delete(key: String): js.Promise[Unit] = js.native
+
+  def list(options: js.UndefOr[ListOptions]): js.Promise[ListResponse]
+
+}
+
+@js.native
+private[worker] trait GetOptions extends js.Object
+
+private[worker] object GetOptions {
+  def apply(
+      `type`: js.UndefOr[String] = js.undefined,
+      cacheTtl: js.UndefOr[Double] = js.undefined
+  ): GetOptions =
+    js.Dynamic.literal(`type` = `type`, cacheTtl = cacheTtl).asInstanceOf[GetOptions]
+}
+
+@js.native
+private[worker] sealed trait KVValueWithMetadata extends js.Object {
+  def value
+      : String | js.Any | js.typedarray.ArrayBuffer | ReadableStream[js.typedarray.Uint8Array] =
+    js.native
+  def metadata: js.Any = js.native
+}
+
+@js.native
+private[worker] trait PutOptions extends js.Object
+
+private[worker] object PutOptions {
+  def apply(
+      expiration: js.UndefOr[Double] = js.undefined,
+      expirationTtl: js.UndefOr[Double] = js.undefined,
+      metadata: js.UndefOr[js.Any] = js.undefined
+  ): PutOptions = js
+    .Dynamic
+    .literal(expiration = expiration, expirationTtl = expirationTtl, metadata = metadata)
+    .asInstanceOf[PutOptions]
+}
+
+@js.native
+private[worker] trait ListOptions extends js.Object
+
+private[worker] object ListOptions {
+  def apply(
+      prefix: js.UndefOr[String] = js.undefined,
+      limit: js.UndefOr[Int] = js.undefined,
+      cursor: js.UndefOr[String] = js.undefined
+  ): ListOptions = js
+    .Dynamic
+    .literal(
+      prefix = prefix,
+      limit = limit,
+      cursor = cursor
+    )
+    .asInstanceOf[ListOptions]
+}
+
+@js.native
+private[worker] sealed trait ListResponse extends js.Object {
+  def keys: js.Array[Key] = js.native
+  def list_complete: Boolean = js.native
+  def cursor: js.UndefOr[String] = js.native
+}
+
+@js.native
+private[worker] sealed trait Key extends js.Object {
+  def name: String = js.native
+  def expiration: js.UndefOr[Double] = js.native
+  def metadata: js.UndefOr[js.Any] = js.native
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ReadableStream.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ReadableStream.scala
new file mode 100644
index 00000000..8b16ad91
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ReadableStream.scala
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker.facade
+
+import scala.scalajs.js
+import scala.annotation.nowarn
+
+@js.native
+@nowarn
+private[worker] sealed trait ReadableStream[R] extends js.Object {
+  def locked: Boolean = js.native
+  def cancel(reason: js.UndefOr[js.Any]): js.Promise[Unit] = js.native
+  def getReader(): ReadableStreamDefaultReader[R] = js.native
+}
+
+@js.native
+private[worker] sealed trait ReadableStreamDefaultReader[R] extends js.Object {
+  def read(): js.Promise[ReadableStreamDefaultReadResult[R]] = js.native
+  def releaseLock(): Unit = js.native
+}
+
+@js.native
+private[worker] sealed trait ReadableStreamDefaultReadResult[R] extends js.Object {
+  def done: Boolean = js.native
+  def value: R = js.native
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Request.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Request.scala
new file mode 100644
index 00000000..668de3c2
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Request.scala
@@ -0,0 +1,42 @@
+package feral.cloudflare.worker.facade
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+import scala.scalajs.js.annotation.JSGlobal
+
+@js.native
+@JSGlobal
+@nowarn
+private[worker] class Request(input: String, init: RequestInit) extends js.Object {
+  def body: ReadableStream[js.typedarray.Uint8Array] = js.native
+  def bodyUsed: Boolean = js.native
+  def cf: IncomingRequestCfProperties = js.native
+  def headers: Headers = js.native
+  def method: String = js.native
+  def redirect: String = js.native
+  def url: String = js.native
+}
+
+private[worker] sealed trait RequestInit extends js.Any
+
+private[worker] object RequestInit {
+  def apply(
+      cf: js.UndefOr[RequestInitCfProperties] = js.undefined,
+      method: js.UndefOr[String] = js.undefined,
+      headers: js.UndefOr[Headers] = js.undefined,
+      body: js.UndefOr[ReadableStream[js.typedarray.Uint8Array]] = js.undefined,
+      redirect: js.UndefOr[String] = js.undefined
+  ): RequestInit =
+    js.Dynamic
+      .literal(
+        cf = cf,
+        method = method,
+        headers = headers,
+        body = body,
+        redirect = redirect
+      ).asInstanceOf[RequestInit]
+}
+
+@js.native
+private[worker] trait IncomingRequestCfProperties extends js.Any
+private[worker] sealed trait RequestInitCfProperties extends js.Any
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Response.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Response.scala
new file mode 100644
index 00000000..fcc2a7f3
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/Response.scala
@@ -0,0 +1,37 @@
+package feral.cloudflare.worker.facade
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+import scala.scalajs.js.annotation.JSGlobal
+
+@js.native
+@JSGlobal
+@nowarn
+private[worker] class Response(
+    body: js.UndefOr[ReadableStream[js.typedarray.Uint8Array]] = js.undefined,
+    init: js.UndefOr[ResponseInit] = js.undefined)
+    extends js.Object {
+  def body: ReadableStream[js.typedarray.Uint8Array] = js.native
+  def bodyUsed: Boolean = js.native
+  def encodeBody: String = js.native
+  def headers: Headers = js.native
+  def ok: Boolean = js.native
+  def redirected: Boolean = js.native
+  def status: Int = js.native
+  def statusText: String = js.native
+  def url: String = js.native
+}
+
+@js.native
+private[worker] sealed trait ResponseInit extends js.Any
+
+private[worker] object ResponseInit {
+  def apply(
+      status: js.UndefOr[Int] = js.undefined,
+      statusText: js.UndefOr[String] = js.undefined,
+      headers: js.UndefOr[Headers] = js.undefined
+  ): ResponseInit =
+    js.Dynamic
+      .literal(status = status, statusText = statusText, headers = headers)
+      .asInstanceOf[ResponseInit]
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ScheduledEvent.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ScheduledEvent.scala
new file mode 100644
index 00000000..21fbd4d5
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/facade/ScheduledEvent.scala
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare.worker.facade
+
+import scala.scalajs.js
+
+@js.native
+private[worker] sealed trait ScheduledEvent extends Event {
+  def cron: String = js.native
+  def scheduledTime: Double = js.native
+}
diff --git a/cloudflare-worker/src/main/scala/feral/cloudflare/worker/package.scala b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/package.scala
new file mode 100644
index 00000000..ac2cb323
--- /dev/null
+++ b/cloudflare-worker/src/main/scala/feral/cloudflare/worker/package.scala
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral.cloudflare
+
+import cats.effect.kernel.Async
+import cats.effect.kernel.Resource
+import cats.syntax.all._
+import fs2.Stream
+import org.http4s.Header
+import org.http4s.Headers
+import org.http4s.Request
+import org.http4s.Response
+
+import scala.annotation.nowarn
+import scala.scalajs.js
+import scala.scalajs.js.JSConverters._
+import org.http4s.Method
+import org.http4s.Uri
+import org.http4s.Status
+
+package object worker {
+
+  @js.native
+  @js.annotation.JSGlobal("addEventListener")
+  @nowarn
+  private[worker] def addEventListener[E <: facade.Event](
+      `type`: String,
+      listener: js.Function1[E, Unit]): Unit = js.native
+
+  private[worker] def fromRequest[F[_]](req: facade.Request)(implicit F: Async[F]): F[Request[F]] = for {
+    method <- F.fromEither(Method.fromString(req.method))
+    uri <- F.fromEither(Uri.fromString(req.url))
+    headers = fromHeaders(req.headers)
+    body = fromReadableStream(req.body)
+  } yield Request(method, uri, headers = headers, body = body)
+
+  private[worker] def toRequest[F[_]](req: Request[F]): facade.Request = ???
+
+  private[worker] def fromResponse[F[_]](res: facade.Response)(implicit F: Async[F]): F[Response[F]] = for {
+    status <- F.fromEither(Status.fromIntAndReason(res.status, res.statusText))
+    headers = fromHeaders(res.headers)
+    body = fromReadableStream(res.body)
+  } yield Response(status, headers = headers, body = body)
+
+  private[worker] def toResponse[F[_]](req: Response[F]): facade.Response = ???
+
+  private[worker] def toHeaders(headers: Headers): facade.Headers =
+    new facade.Headers(
+      headers
+        .headers
+        .view
+        .map {
+          case Header.Raw(name, value) =>
+            name.toString -> value
+        }
+        .toMap
+        .toJSDictionary)
+
+  private[worker] def fromHeaders(headers: facade.Headers): Headers =
+    Headers(
+      headers.toIterable.map { header => header(0) -> header(1) }.toList
+    )
+
+  private[worker] def fromReadableStream[F[_]](
+      rs: facade.ReadableStream[js.typedarray.Uint8Array])(
+      implicit F: Async[F]): Stream[F, Byte] =
+    Stream.bracket(F.delay(rs.getReader()))(r => F.delay(r.releaseLock())).flatMap { reader =>
+      Stream.unfoldChunkEval(reader) { reader =>
+        F.fromPromise(F.delay(reader.read())).map { chunk =>
+          if (chunk.done)
+            None
+          else
+            Some((fs2.Chunk.uint8Array(chunk.value), reader))
+        }
+      }
+    }
+
+  private[worker] def toReadableStream[F[_]](s: Stream[F, Byte]): facade.ReadableStream[js.typedarray.Uint8Array] = ???
+
+  private[worker] def closeReadableStream[F[_], A](
+      rs: facade.ReadableStream[A],
+      exitCase: Resource.ExitCase)(implicit F: Async[F]): F[Unit] = exitCase match {
+    case Resource.ExitCase.Succeeded =>
+      F.fromPromise(F.delay(rs.cancel(js.undefined))).void
+    case Resource.ExitCase.Errored(ex) =>
+      F.fromPromise(F.delay(rs.cancel(ex.toString().asInstanceOf[js.Any]))).void
+    case Resource.ExitCase.Canceled =>
+      F.fromPromise(F.delay(rs.cancel(js.undefined))).void
+  }
+
+}
diff --git a/core/src/main/scala/feral/IOSetup.scala b/core/src/main/scala/feral/IOSetup.scala
new file mode 100644
index 00000000..8cf84dca
--- /dev/null
+++ b/core/src/main/scala/feral/IOSetup.scala
@@ -0,0 +1,45 @@
+/*
+ * Copyright 2021 Typelevel
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package feral
+
+import cats.effect.unsafe.IORuntime
+import cats.effect.kernel.Resource
+import cats.effect.IO
+import cats.effect.kernel.Deferred
+import cats.syntax.all._
+
+trait IOSetup {
+  
+  protected def runtime: IORuntime = IORuntime.global
+
+  protected type Setup
+  protected val setup: Resource[IO, Setup] = Resource.pure(null.asInstanceOf[Setup])
+
+  private[feral] final val setupMemo: IO[Setup] = {
+    val deferred = Deferred.unsafe[IO, Either[Throwable, Setup]]
+    setup
+      .attempt
+      .allocated
+      .flatTap {
+        case (setup, _) =>
+          deferred.complete(setup)
+      }
+      .unsafeRunAndForget()(runtime)
+    deferred.get.rethrow
+  }
+
+}
diff --git a/lambda/shared/src/main/scala/feral/lambda/IOLambda.scala b/lambda/shared/src/main/scala/feral/lambda/IOLambda.scala
index d5e7e0a0..81d22e81 100644
--- a/lambda/shared/src/main/scala/feral/lambda/IOLambda.scala
+++ b/lambda/shared/src/main/scala/feral/lambda/IOLambda.scala
@@ -14,38 +14,18 @@
  * limitations under the License.
  */
 
-package feral.lambda
+package feral
+package lambda
 
-import cats.effect.Deferred
 import cats.effect.IO
-import cats.effect.Resource
-import cats.effect.unsafe.IORuntime
-import cats.syntax.all._
 import io.circe.Decoder
 import io.circe.Encoder
 
 abstract class IOLambda[Event, Result](
     implicit private[lambda] val decoder: Decoder[Event],
     private[lambda] val encoder: Encoder[Result]
-) extends IOLambdaPlatform[Event, Result] {
-
-  protected def runtime: IORuntime = IORuntime.global
-
-  protected type Setup
-  protected val setup: Resource[IO, Setup] = Resource.pure(null.asInstanceOf[Setup])
-
-  private[lambda] final val setupMemo: IO[Setup] = {
-    val deferred = Deferred.unsafe[IO, Either[Throwable, Setup]]
-    setup
-      .attempt
-      .allocated
-      .flatTap {
-        case (setup, _) =>
-          deferred.complete(setup)
-      }
-      .unsafeRunAndForget()(runtime)
-    deferred.get.rethrow
-  }
+) extends IOLambdaPlatform[Event, Result]
+    with IOSetup {
 
   def apply(event: Event, context: Context, setup: Setup): IO[Option[Result]]
 }