diff --git a/lambda/shared/src/main/scala/feral/lambda/events/ConfigEvent.scala b/lambda/shared/src/main/scala/feral/lambda/events/ConfigEvent.scala
new file mode 100644
index 00000000..fefe3bf9
--- /dev/null
+++ b/lambda/shared/src/main/scala/feral/lambda/events/ConfigEvent.scala
@@ -0,0 +1,92 @@
+/*
+ * 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
+
+// AWS Config custom rule Lambda event. DefinitelyTyped trigger/config is TODO.
+// See: https://docs.aws.amazon.com/config/latest/developerguide/evaluate-config_develop-rules_lambda-functions.html
+// invokingEvent and ruleParameters are JSON strings; parse separately if needed.
+
+sealed abstract class ConfigEvent {
+  def invokingEvent: String
+  def ruleParameters: String
+  def resultToken: String
+  def eventLeftScope: Boolean
+  def executionRoleArn: String
+  def configRuleArn: String
+  def configRuleName: String
+  def configRuleId: String
+  def accountId: String
+  def version: String
+}
+
+object ConfigEvent {
+  def apply(
+      invokingEvent: String,
+      ruleParameters: String,
+      resultToken: String,
+      eventLeftScope: Boolean,
+      executionRoleArn: String,
+      configRuleArn: String,
+      configRuleName: String,
+      configRuleId: String,
+      accountId: String,
+      version: String
+  ): ConfigEvent =
+    new Impl(
+      invokingEvent,
+      ruleParameters,
+      resultToken,
+      eventLeftScope,
+      executionRoleArn,
+      configRuleArn,
+      configRuleName,
+      configRuleId,
+      accountId,
+      version
+    )
+
+  implicit val decoder: Decoder[ConfigEvent] =
+    Decoder.forProduct10(
+      "invokingEvent",
+      "ruleParameters",
+      "resultToken",
+      "eventLeftScope",
+      "executionRoleArn",
+      "configRuleArn",
+      "configRuleName",
+      "configRuleId",
+      "accountId",
+      "version"
+    )(ConfigEvent.apply)
+
+  private final case class Impl(
+      invokingEvent: String,
+      ruleParameters: String,
+      resultToken: String,
+      eventLeftScope: Boolean,
+      executionRoleArn: String,
+      configRuleArn: String,
+      configRuleName: String,
+      configRuleId: String,
+      accountId: String,
+      version: String
+  ) extends ConfigEvent {
+    override def productPrefix = "ConfigEvent"
+  }
+}
diff --git a/lambda/shared/src/main/scala/feral/lambda/events/IoTButtonEvent.scala b/lambda/shared/src/main/scala/feral/lambda/events/IoTButtonEvent.scala
new file mode 100644
index 00000000..f773731e
--- /dev/null
+++ b/lambda/shared/src/main/scala/feral/lambda/events/IoTButtonEvent.scala
@@ -0,0 +1,67 @@
+/*
+ * 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
+
+// AWS IoT Button payload. DefinitelyTyped trigger/iot.d.ts models IoTEvent as string | number | T
+// (no fixed structure). This model follows the documented AWS IoT Button payload:
+// https://docs.aws.amazon.com/lambda/latest/dg/services-iot.html (IoT as trigger)
+// clickType: SINGLE | DOUBLE | LONG, serialNumber, batteryVoltage (e.g. "1584mV")
+
+sealed abstract class IoTButtonEvent {
+  def clickType: IoTButtonEvent.ClickType
+  def serialNumber: String
+  def batteryVoltage: String
+}
+
+object IoTButtonEvent {
+
+  sealed abstract class ClickType
+  object ClickType {
+    case object Single extends ClickType
+    case object Double extends ClickType
+    case object Long extends ClickType
+
+    implicit val decoder: Decoder[ClickType] = Decoder.decodeString.emap {
+      case "SINGLE" => Right(Single)
+      case "DOUBLE" => Right(Double)
+      case "LONG" => Right(Long)
+      case other => Left(s"Unknown click type: $other")
+    }
+  }
+
+  def apply(
+      clickType: ClickType,
+      serialNumber: String,
+      batteryVoltage: String
+  ): IoTButtonEvent =
+    new Impl(clickType, serialNumber, batteryVoltage)
+
+  implicit val decoder: Decoder[IoTButtonEvent] =
+    Decoder.forProduct3("clickType", "serialNumber", "batteryVoltage")(
+      IoTButtonEvent.apply
+    )
+
+  private final case class Impl(
+      clickType: ClickType,
+      serialNumber: String,
+      batteryVoltage: String
+  ) extends IoTButtonEvent {
+    override def productPrefix = "IoTButtonEvent"
+  }
+}
diff --git a/lambda/shared/src/test/scala/feral/lambda/events/ConfigEventSuite.scala b/lambda/shared/src/test/scala/feral/lambda/events/ConfigEventSuite.scala
new file mode 100644
index 00000000..b6b8396e
--- /dev/null
+++ b/lambda/shared/src/test/scala/feral/lambda/events/ConfigEventSuite.scala
@@ -0,0 +1,63 @@
+/*
+ * 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.Json
+import io.circe.literal._
+import munit.FunSuite
+
+class ConfigEventSuite extends FunSuite {
+  import ConfigEventSuite._
+
+  test("decoder") {
+    assertEquals(configEvent.as[ConfigEvent].toTry.get, decoded)
+  }
+}
+
+object ConfigEventSuite {
+
+  val decoded: ConfigEvent =
+    ConfigEvent(
+      invokingEvent =
+        """{"messageType":"ConfigurationItemChangeNotification","configurationItem":{}}""",
+      ruleParameters = """{"desiredInstanceType":"t2.micro"}""",
+      resultToken = "testResultToken123",
+      eventLeftScope = false,
+      executionRoleArn = "arn:aws:iam::123456789012:role/config-role",
+      configRuleArn = "arn:aws:config:us-east-1:123456789012:config-rule/config-rule-012345",
+      configRuleName = "instance-type-check",
+      configRuleId = "config-rule-012345",
+      accountId = "123456789012",
+      version = "1.0"
+    )
+
+  // https://docs.aws.amazon.com/config/latest/developerguide/evaluate-config_develop-rules_lambda-functions.html
+  val configEvent: Json = json"""
+    {
+      "invokingEvent": "{\"messageType\":\"ConfigurationItemChangeNotification\",\"configurationItem\":{}}",
+      "ruleParameters": "{\"desiredInstanceType\":\"t2.micro\"}",
+      "resultToken": "testResultToken123",
+      "eventLeftScope": false,
+      "executionRoleArn": "arn:aws:iam::123456789012:role/config-role",
+      "configRuleArn": "arn:aws:config:us-east-1:123456789012:config-rule/config-rule-012345",
+      "configRuleName": "instance-type-check",
+      "configRuleId": "config-rule-012345",
+      "accountId": "123456789012",
+      "version": "1.0"
+    }
+  """
+}
diff --git a/lambda/shared/src/test/scala/feral/lambda/events/IoTButtonEventSuite.scala b/lambda/shared/src/test/scala/feral/lambda/events/IoTButtonEventSuite.scala
new file mode 100644
index 00000000..d3aef8ab
--- /dev/null
+++ b/lambda/shared/src/test/scala/feral/lambda/events/IoTButtonEventSuite.scala
@@ -0,0 +1,67 @@
+/*
+ * 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.Json
+import io.circe.literal._
+import munit.FunSuite
+
+class IoTButtonEventSuite extends FunSuite {
+  import IoTButtonEventSuite._
+
+  test("decoder SINGLE click") {
+    assertEquals(singleClickEvent.as[IoTButtonEvent].toTry.get, decodedSingle)
+  }
+
+  test("decoder LONG click") {
+    assertEquals(longClickEvent.as[IoTButtonEvent].toTry.get, decodedLong)
+  }
+}
+
+object IoTButtonEventSuite {
+
+  val decodedSingle: IoTButtonEvent =
+    IoTButtonEvent(
+      clickType = IoTButtonEvent.ClickType.Single,
+      serialNumber = "G030PM00000000000000",
+      batteryVoltage = "1584mV"
+    )
+
+  val decodedLong: IoTButtonEvent =
+    IoTButtonEvent(
+      clickType = IoTButtonEvent.ClickType.Long,
+      serialNumber = "G030PM00000000000000",
+      batteryVoltage = "1584mV"
+    )
+
+  // AWS IoT Button payload: https://docs.aws.amazon.com/lambda/latest/dg/services-iot.html
+  val singleClickEvent: Json = json"""
+    {
+      "clickType": "SINGLE",
+      "serialNumber": "G030PM00000000000000",
+      "batteryVoltage": "1584mV"
+    }
+  """
+
+  val longClickEvent: Json = json"""
+    {
+      "clickType": "LONG",
+      "serialNumber": "G030PM00000000000000",
+      "batteryVoltage": "1584mV"
+    }
+  """
+}