diff --git a/build.gradle.kts b/build.gradle.kts
index f23f144..bfae4e2 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -6,7 +6,7 @@ plugins {
 }
 
 group = "dev.adamko.kafkatorio"
-version = "0.2.6"
+version = "0.2.7"
 
 val licenseFile: RegularFile by extra(layout.projectDirectory.file("LICENSE"))
 
diff --git a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioLuaObjects.kt b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioLuaObjects.kt
index 63d0c43..d142fbb 100644
--- a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioLuaObjects.kt
+++ b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioLuaObjects.kt
@@ -1,5 +1,6 @@
 package dev.adamko.kafkatorio.events.schema
 
+import kotlinx.serialization.Contextual
 import kotlinx.serialization.DeserializationStrategy
 import kotlinx.serialization.EncodeDefault
 import kotlinx.serialization.Serializable
@@ -9,7 +10,7 @@ import kotlinx.serialization.json.contentOrNull
 import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
 
-@Serializable(with = FactorioObjectDataSerializer::class)
+@Serializable(with = FactorioObjectDataJsonSerializer::class)
 sealed class FactorioObjectData {
 
   @EncodeDefault
@@ -43,7 +44,7 @@ sealed class FactorioObjectData {
   }
 }
 
-object FactorioObjectDataSerializer : JsonContentPolymorphicSerializer<FactorioObjectData>(
+object FactorioObjectDataJsonSerializer : JsonContentPolymorphicSerializer<FactorioObjectData>(
   FactorioObjectData::class
 ) {
   private val key = FactorioObjectData::objectName.name
@@ -58,6 +59,8 @@ object FactorioObjectDataSerializer : JsonContentPolymorphicSerializer<FactorioO
         FactorioObjectData.ObjectName.values().firstOrNull { it.name == json }
       }
 
+    requireNotNull(type) { "Unknown FactorioObjectData $key: $element" }
+
     return when (type) {
       FactorioObjectData.ObjectName.LuaPlayer          -> PlayerData.serializer()
       FactorioObjectData.ObjectName.LuaEntity          -> EntityData.serializer()
@@ -66,8 +69,6 @@ object FactorioObjectDataSerializer : JsonContentPolymorphicSerializer<FactorioO
       FactorioObjectData.ObjectName.LuaTile            -> MapTile.serializer()
       FactorioObjectData.ObjectName.LuaTiles           -> MapTiles.serializer()
       FactorioObjectData.ObjectName.ConsoleChatMessage -> ConsoleChatMessage.serializer()
-      null                                             ->
-        throw Exception("Unknown FactorioObjectData $key: '$type' ")
     }
   }
 }
@@ -75,7 +76,8 @@ object FactorioObjectDataSerializer : JsonContentPolymorphicSerializer<FactorioO
 
 @Serializable
 data class PlayerData(
-  @Serializable(with = ListAsObjectSerializer::class)
+//  @Serializable(with = FactorioJsonListSerializer::class)
+  @Contextual
   val associatedCharactersUnitNumbers: List<UInt>,
   val characterUnitNumber: UInt?,
   val name: String,
diff --git a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioPrototypes.kt b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioPrototypes.kt
index 31dfabd..8fc42ea 100644
--- a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioPrototypes.kt
+++ b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/factorioPrototypes.kt
@@ -1,5 +1,7 @@
 package dev.adamko.kafkatorio.events.schema
 
+import dev.adamko.kafkatorio.events.schema.FactorioPrototype.PrototypeObjectName
+import kotlinx.serialization.Contextual
 import kotlinx.serialization.DeserializationStrategy
 import kotlinx.serialization.EncodeDefault
 import kotlinx.serialization.Serializable
@@ -20,7 +22,7 @@ data class FactorioPrototypes(
 }
 
 
-@Serializable(with = FactorioPrototypeSerializer::class)
+@Serializable(with = FactorioPrototypeJsonSerializer::class)
 sealed class FactorioPrototype {
   @EncodeDefault
   abstract val prototypeObjectName: PrototypeObjectName
@@ -30,7 +32,8 @@ sealed class FactorioPrototype {
   }
 }
 
-object FactorioPrototypeSerializer : JsonContentPolymorphicSerializer<FactorioPrototype>(
+
+object FactorioPrototypeJsonSerializer : JsonContentPolymorphicSerializer<FactorioPrototype>(
   FactorioPrototype::class
 ) {
   private val key = FactorioPrototype::prototypeObjectName.name
@@ -42,13 +45,13 @@ object FactorioPrototypeSerializer : JsonContentPolymorphicSerializer<FactorioPr
       ?.jsonPrimitive
       ?.contentOrNull
       ?.let { json ->
-        FactorioPrototype.PrototypeObjectName.values().firstOrNull { it.name == json }
+        PrototypeObjectName.values().firstOrNull { it.name == json }
       }
 
+    requireNotNull(type) { "Unknown FactorioPrototype ${key}: $element" }
+
     return when (type) {
-      FactorioPrototype.PrototypeObjectName.LuaTilePrototype -> MapTilePrototype.serializer()
-      null                                                   ->
-        throw Exception("Unknown FactorioPrototype $key: '$type' ")
+      PrototypeObjectName.LuaTilePrototype -> MapTilePrototype.serializer()
     }
   }
 }
@@ -59,7 +62,8 @@ data class MapTilePrototype(
   val name: String,
   val layer: UInt,
   val mapColour: Colour,
-  @Serializable(with = FactorioJsonListSerializer::class)
+//  @Serializable(with = FactorioJsonListSerializer::class)
+  @Contextual
   val collisionMasks: List<String>,
   val order: String,
   /** Can the tile be mined for resources? */
diff --git a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/json.kt b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/json.kt
index e477521..0c4642e 100644
--- a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/json.kt
+++ b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/json.kt
@@ -7,46 +7,62 @@ import kotlinx.serialization.json.JsonArray
 import kotlinx.serialization.json.JsonElement
 import kotlinx.serialization.json.JsonObject
 import kotlinx.serialization.json.JsonTransformingSerializer
-import kotlinx.serialization.json.jsonArray
-import kotlinx.serialization.json.jsonObject
+import kotlinx.serialization.json.buildJsonObject
+import kotlinx.serialization.modules.SerializersModule
 
 val jsonMapperKafkatorio = Json {
   prettyPrint = true
   prettyPrintIndent = "  "
-//  serializersModule =  FactorioEvent.kxsModule
-//  serializersModule = KafkatorioPacket.kxsModule + FactorioEvent.kxsModule
-//  serializersModule = SerializersModule { }
+
+  serializersModule = SerializersModule {
+    contextual(List::class) { args -> FactorioJsonListSerializer(args[0]) }
+  }
+
 }
 
 
-/** Factorio outputs lists as Json objects - this serializer converts an object back to a list. */
-// actually I'm not sure that it does - I think *empty* lists get encoded as *empty* objects
-internal class ListAsObjectSerializer<T>(dataSerializer: KSerializer<T>) :
-  JsonTransformingSerializer<List<T>>(ListSerializer(dataSerializer)) {
-
-  override fun transformDeserialize(element: JsonElement): JsonElement =
-    JsonArray(
-      element.jsonObject.values.toList()
-    )
-
-  override fun transformSerialize(element: JsonElement): JsonElement =
-    JsonObject(
-      element.jsonArray.mapIndexed { index, jsonElement -> "$index" to jsonElement }.toMap()
-    )
-}
-
-
-/** Factorio outputs lists as Json objects - this serializer converts an object back to a list. */
-// actually I'm not sure that it does - I think *empty* lists get encoded as *empty* objects
-internal class FactorioJsonListSerializer<T>(dataSerializer: KSerializer<T>) :
+/**
+ * Factorio outputs an *empty* list as an *empty* Json object. This serde performs the same
+ * conversion
+ */
+class FactorioJsonListSerializer<T>(dataSerializer: KSerializer<T>) :
   JsonTransformingSerializer<List<T>>(ListSerializer(dataSerializer)) {
 
   override fun transformDeserialize(element: JsonElement): JsonElement {
-    return if (element is JsonObject) {
-      JsonArray(emptyList())
-    } else {
-      element
+    return when (element) {
+      is JsonObject -> JsonArray(emptyList())
+      else          -> element
+    }
+  }
+
+  override fun transformSerialize(element: JsonElement): JsonElement {
+    return when {
+      element is JsonArray && element.isEmpty() -> buildJsonObject { }
+      else                                      -> element
     }
   }
 
 }
+
+//internal class FactorioListSerializer<T : Any>(
+//  private val tSerializer: KSerializer<T>
+//) : KSerializer<List<T>> {
+//
+//  override val descriptor: SerialDescriptor get() = tSerializer.descriptor
+//  private val tListSerializer = ListSerializer(tSerializer)
+//  private val jsonTransformer = FactorioJsonListSerializer(tSerializer)
+//
+//  override fun serialize(encoder: Encoder, value: List<T>) {
+//    when (encoder) {
+//      is JsonEncoder -> jsonTransformer.serialize(encoder, value)
+//      else           -> tListSerializer.serialize(encoder, value)
+//    }
+//  }
+//
+//  override fun deserialize(decoder: Decoder): List<T> {
+//    return when (decoder) {
+//      is JsonDecoder -> jsonTransformer.deserialize(decoder)
+//      else           -> tListSerializer.deserialize(decoder)
+//    }
+//  }
+//}
diff --git a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/kafkatorioPacket.kt b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/kafkatorioPacket.kt
index 56e86cb..cb98d95 100644
--- a/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/kafkatorioPacket.kt
+++ b/modules/events-schema/src/commonMain/kotlin/dev/adamko/kafkatorio/events/schema/kafkatorioPacket.kt
@@ -10,7 +10,7 @@ import kotlinx.serialization.json.jsonObject
 import kotlinx.serialization.json.jsonPrimitive
 
 
-@Serializable(with = KafkatorioPacketSerializer::class)
+@Serializable(with = KafkatorioPacketJsonSerializer::class)
 sealed class KafkatorioPacket {
   /** Schema versioning */
   abstract val modVersion: String
@@ -24,7 +24,8 @@ sealed class KafkatorioPacket {
   }
 }
 
-object KafkatorioPacketSerializer : JsonContentPolymorphicSerializer<KafkatorioPacket>(
+
+object KafkatorioPacketJsonSerializer : JsonContentPolymorphicSerializer<KafkatorioPacket>(
   KafkatorioPacket::class
 ) {
   private val key = KafkatorioPacket::packetType.name
@@ -39,12 +40,12 @@ object KafkatorioPacketSerializer : JsonContentPolymorphicSerializer<KafkatorioP
         KafkatorioPacket.PacketType.values().firstOrNull { it.name == json }
       }
 
+    requireNotNull(type) { "Unknown KafkatorioPacket ${key}: $element" }
+
     return when (type) {
-      KafkatorioPacket.PacketType.EVENT  -> FactorioEvent.serializer()
-      KafkatorioPacket.PacketType.CONFIG -> FactorioConfigurationUpdate.serializer()
+      KafkatorioPacket.PacketType.EVENT      -> FactorioEvent.serializer()
+      KafkatorioPacket.PacketType.CONFIG     -> FactorioConfigurationUpdate.serializer()
       KafkatorioPacket.PacketType.PROTOTYPES -> FactorioPrototypes.serializer()
-      null                               ->
-        throw Exception("Unknown KafkatorioPacket ${key}: '$type' ")
     }
   }
 }
diff --git a/modules/infra-factorio-server/src/.env b/modules/infra-factorio-server/src/.env
index 129db2a..aecb9bc 100644
--- a/modules/infra-factorio-server/src/.env
+++ b/modules/infra-factorio-server/src/.env
@@ -1,4 +1,4 @@
 # Do not edit manually. This file was created with task 'dockerEnv'
 COMPOSE_PROJECT_NAME=kafkatorio
 FACTORIO_VERSION=1.1.53
-KAFKATORIO_VERSION=0.2.6
+KAFKATORIO_VERSION=0.2.7
diff --git a/modules/infra-kafka-cluster/src/.env b/modules/infra-kafka-cluster/src/.env
index afa5814..1ebae11 100644
--- a/modules/infra-kafka-cluster/src/.env
+++ b/modules/infra-kafka-cluster/src/.env
@@ -1,3 +1,3 @@
 # Do not edit manually. This file was created with task 'dockerEnv'
 COMPOSE_PROJECT_NAME=kafkatorio
-KAFKATORIO_VERSION=0.2.6
+KAFKATORIO_VERSION=0.2.7
diff --git a/modules/infra-kafka-pipe/src/.env b/modules/infra-kafka-pipe/src/.env
index afa5814..1ebae11 100644
--- a/modules/infra-kafka-pipe/src/.env
+++ b/modules/infra-kafka-pipe/src/.env
@@ -1,3 +1,3 @@
 # Do not edit manually. This file was created with task 'dockerEnv'
 COMPOSE_PROJECT_NAME=kafkatorio
-KAFKATORIO_VERSION=0.2.6
+KAFKATORIO_VERSION=0.2.7