diff --git a/Source/ARTBaseMessage.m b/Source/ARTBaseMessage.m
index 48676a629..7201f09e8 100644
--- a/Source/ARTBaseMessage.m
+++ b/Source/ARTBaseMessage.m
@@ -21,6 +21,7 @@ - (id)copyWithZone:(NSZone *)zone {
     message->_data = [self.data copy];
     message->_connectionId = self.connectionId;
     message->_encoding = self.encoding;
+    message->_extras = self.extras;
     return message;
 }
 
diff --git a/Source/ARTJsonLikeEncoder.m b/Source/ARTJsonLikeEncoder.m
index d63c08439..8059519bc 100644
--- a/Source/ARTJsonLikeEncoder.m
+++ b/Source/ARTJsonLikeEncoder.m
@@ -275,6 +275,8 @@ - (ARTMessage *)messageFromDictionary:(NSDictionary *)input {
     ARTMessage *message = [[ARTMessage alloc] init];
     message.id = [input artString:@"id"];
     message.name = [input artString:@"name"];
+    message.action = ([input artNumber:@"action"] ?: [[NSNumber alloc] initWithInt:ARTMessageCreate]).integerValue;
+    message.serial = [input artString:@"serial"];
     message.clientId = [input artString:@"clientId"];
     message.data = [input objectForKey:@"data"];
     message.encoding = [input artString:@"encoding"];;
diff --git a/Source/ARTMessage.m b/Source/ARTMessage.m
index 0ebf065da..eaba86d54 100644
--- a/Source/ARTMessage.m
+++ b/Source/ARTMessage.m
@@ -40,7 +40,8 @@ - (NSString *)description {
 - (id)copyWithZone:(NSZone *)zone {
     ARTMessage *message = [super copyWithZone:zone];
     message.name = self.name;
-    message.extras = self.extras;
+    message.action = self.action;
+    message.serial = self.serial;
     return message;
 }
 
diff --git a/Source/include/Ably/ARTMessage.h b/Source/include/Ably/ARTMessage.h
index 88d145170..e7b827156 100644
--- a/Source/include/Ably/ARTMessage.h
+++ b/Source/include/Ably/ARTMessage.h
@@ -4,6 +4,17 @@
 #import <Ably/ARTTypes.h>
 #import <Ably/ARTChannelOptions.h>
 
+NS_SWIFT_SENDABLE
+typedef NS_ENUM(NSUInteger, ARTMessageAction) {
+    ARTMessageUnset,
+    ARTMessageCreate,
+    ARTMessageUpdate,
+    ARTMessageDelete,
+    ARTMessageAnnotationCreate,
+    ARTMessageAnnotationDelete,
+    ARTMessageMetaOccupancy,
+};
+
 NS_ASSUME_NONNULL_BEGIN
 
 /**
@@ -14,6 +25,12 @@ NS_ASSUME_NONNULL_BEGIN
 /// The event name, if available
 @property (nullable, readwrite, nonatomic) NSString *name;
 
+/// The action identifier
+@property (readwrite, nonatomic) ARTMessageAction action;
+
+/// The serial lexicographic identifier
+@property (nullable, readwrite, nonatomic) NSString *serial;
+
 /**
  * Construct an `ARTMessage` object with an event name and payload.
  *