diff --git a/lambda/shared/src/main/scala/feral/lambda/events/ApplicationLoadBalancerResponseEvent.scala b/lambda/shared/src/main/scala/feral/lambda/events/ApplicationLoadBalancerResponseEvent.scala
new file mode 100644
index 00000000..dabec6d9
--- /dev/null
+++ b/lambda/shared/src/main/scala/feral/lambda/events/ApplicationLoadBalancerResponseEvent.scala
@@ -0,0 +1,91 @@
+/*
+ * 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.lambda.events
+
+import io.circe.Decoder
+import io.circe.Encoder
+import io.circe.KeyDecoder
+import io.circe.KeyEncoder
+import org.typelevel.ci.CIString
+
+sealed abstract class ApplicationLoadBalancerResponseEvent {
+  def statusCode: Int
+  def statusDescription: Option[String]
+  def headers: Option[Map[CIString, String]]
+  def multiValueHeaders: Option[Map[CIString, List[String]]]
+  def body: Option[String]
+  def isBase64Encoded: Boolean
+}
+
+object ApplicationLoadBalancerResponseEvent {
+  implicit val ciStringKeyEncoder: KeyEncoder[CIString] =
+    KeyEncoder.encodeKeyString.contramap(_.toString)
+  implicit val ciStringKeyDecoder: KeyDecoder[CIString] =
+    KeyDecoder.decodeKeyString.map(CIString(_))
+
+  private implicit val mapStringEncoder: Encoder[Map[CIString, String]] =
+    Encoder.encodeMap[CIString, String]
+  private implicit val mapListEncoder: Encoder[Map[CIString, List[String]]] =
+    Encoder.encodeMap[CIString, List[String]]
+
+  def apply(
+      statusCode: Int,
+      statusDescription: Option[String],
+      headers: Option[Map[CIString, String]],
+      multiValueHeaders: Option[Map[CIString, List[String]]],
+      body: Option[String],
+      isBase64Encoded: Boolean
+  ): ApplicationLoadBalancerResponseEvent =
+    Impl(statusCode, statusDescription, headers, multiValueHeaders, body, isBase64Encoded)
+
+  implicit val encoder: Encoder[ApplicationLoadBalancerResponseEvent] =
+    Encoder.forProduct6(
+      "statusCode",
+      "statusDescription",
+      "headers",
+      "multiValueHeaders",
+      "body",
+      "isBase64Encoded"
+    )(x =>
+      (
+        x.statusCode,
+        x.statusDescription,
+        x.headers,
+        x.multiValueHeaders,
+        x.body,
+        x.isBase64Encoded
+      ))
+
+  implicit val decoder: Decoder[ApplicationLoadBalancerResponseEvent] =
+    Decoder.forProduct6(
+      "statusCode",
+      "statusDescription",
+      "headers",
+      "multiValueHeaders",
+      "body",
+      "isBase64Encoded"
+    )(ApplicationLoadBalancerResponseEvent.apply)
+
+  private final case class Impl(
+      statusCode: Int,
+      statusDescription: Option[String],
+      headers: Option[Map[CIString, String]],
+      multiValueHeaders: Option[Map[CIString, List[String]]],
+      body: Option[String],
+      isBase64Encoded: Boolean
+  ) extends ApplicationLoadBalancerResponseEvent
+}