diff --git a/packages/stream_chat/lib/src/api/channel.dart b/packages/stream_chat/lib/src/api/channel.dart
index f868e6e0..90bd6025 100644
--- a/packages/stream_chat/lib/src/api/channel.dart
+++ b/packages/stream_chat/lib/src/api/channel.dart
@@ -59,13 +59,12 @@ class Channel {
   /// Returns true if the channel is muted
   bool get isMuted =>
       _client.state.user?.channelMutes
-          .any((element) => element.channel!.cid == cid) ==
+          .any((element) => element.channel.cid == cid) ==
       true;
 
   /// Returns true if the channel is muted as a stream
   Stream<bool>? get isMutedStream => _client.state.userStream.map((event) =>
-      event!.channelMutes.any((element) => element.channel!.cid == cid) ==
-      true);
+      event!.channelMutes.any((element) => element.channel.cid == cid) == true);
 
   /// True if the channel is a group
   bool get isGroup => memberCount != 2;
@@ -74,85 +73,130 @@ class Channel {
   bool get isDistinct => id?.startsWith('!members') == true;
 
   /// Channel configuration
-  ChannelConfig? get config => state?._channelState?.channel?.config;
+  ChannelConfig? get config {
+    _checkInitialized();
+    return state?._channelState?.channel?.config;
+  }
 
   /// Channel configuration as a stream
-  Stream<ChannelConfig?>? get configStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.config);
+  Stream<ChannelConfig?>? get configStream {
+    _checkInitialized();
+    return state?.channelStateStream.map((cs) => cs!.channel?.config);
+  }
 
   /// Channel user creator
-  User? get createdBy => state?._channelState?.channel?.createdBy;
+  User? get createdBy {
+    _checkInitialized();
+    return state?._channelState?.channel?.createdBy;
+  }
 
   /// Channel user creator as a stream
-  Stream<User?>? get createdByStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.createdBy);
+  Stream<User?>? get createdByStream {
+    _checkInitialized();
+    return state?.channelStateStream.map((cs) => cs!.channel?.createdBy);
+  }
 
   /// Channel frozen status
-  bool? get frozen => state?._channelState?.channel?.frozen;
+  bool? get frozen {
+    _checkInitialized();
+    return state?._channelState?.channel?.frozen;
+  }
 
   /// Channel frozen status as a stream
-  Stream<bool?>? get frozenStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.frozen);
+  Stream<bool?>? get frozenStream {
+    _checkInitialized();
+    return state?.channelStateStream.map((cs) => cs!.channel?.frozen);
+  }
 
   /// Channel creation date
-  DateTime? get createdAt => state?._channelState?.channel?.createdAt;
+  DateTime? get createdAt {
+    _checkInitialized();
+    return state?._channelState?.channel?.createdAt;
+  }
 
   /// Channel creation date as a stream
-  Stream<DateTime?>? get createdAtStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.createdAt);
+  Stream<DateTime?>? get createdAtStream {
+    _checkInitialized();
+    return state?.channelStateStream.map((cs) => cs!.channel?.createdAt);
+  }
 
   /// Channel last message date
-  DateTime? get lastMessageAt => state?._channelState?.channel?.lastMessageAt;
+  DateTime? get lastMessageAt {
+    _checkInitialized();
+
+    return state?._channelState?.channel?.lastMessageAt;
+  }
 
   /// Channel last message date as a stream
-  Stream<DateTime?>? get lastMessageAtStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.lastMessageAt);
+  Stream<DateTime?>? get lastMessageAtStream {
+    _checkInitialized();
+
+    return state?.channelStateStream.map((cs) => cs!.channel?.lastMessageAt);
+  }
 
   /// Channel updated date
-  DateTime? get updatedAt => state?._channelState?.channel?.updatedAt;
+  DateTime? get updatedAt {
+    _checkInitialized();
+
+    return state?._channelState?.channel?.updatedAt;
+  }
 
   /// Channel updated date as a stream
-  Stream<DateTime?>? get updatedAtStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.updatedAt);
+  Stream<DateTime?>? get updatedAtStream {
+    _checkInitialized();
+
+    return state?.channelStateStream.map((cs) => cs!.channel?.updatedAt);
+  }
 
   /// Channel deletion date
-  DateTime? get deletedAt => state?._channelState?.channel?.deletedAt;
+  DateTime? get deletedAt {
+    _checkInitialized();
+
+    return state?._channelState?.channel?.deletedAt;
+  }
 
   /// Channel deletion date as a stream
-  Stream<DateTime?>? get deletedAtStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.deletedAt);
+  Stream<DateTime?>? get deletedAtStream {
+    _checkInitialized();
+
+    return state?.channelStateStream.map((cs) => cs!.channel?.deletedAt);
+  }
 
   /// Channel member count
-  int? get memberCount => state?._channelState?.channel?.memberCount;
+  int? get memberCount {
+    _checkInitialized();
+
+    return state?._channelState?.channel?.memberCount;
+  }
 
   /// Channel member count as a stream
-  Stream<int?>? get memberCountStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.memberCount);
+  Stream<int?>? get memberCountStream {
+    _checkInitialized();
+
+    return state?.channelStateStream.map((cs) => cs!.channel?.memberCount);
+  }
 
   /// Channel id
   String? get id => state?._channelState?.channel?.id ?? _id;
 
-  /// Channel id as a stream
-  Stream<String?>? get idStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.id ?? _id);
-
   /// Channel cid
   String? get cid => state?._channelState?.channel?.cid ?? _cid;
 
   /// Channel team
-  String? get team => state?._channelState?.channel?.team;
-
-  /// Channel cid as a stream
-  Stream<String?>? get cidStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.cid ?? _cid);
+  String? get team {
+    _checkInitialized();
+    return state?._channelState?.channel?.team;
+  }
 
   /// Channel extra data
   Map<String, dynamic>? get extraData =>
       state?._channelState?.channel?.extraData ?? _extraData;
 
   /// Channel extra data as a stream
-  Stream<Map<String, dynamic>?>? get extraDataStream =>
-      state?.channelStateStream.map((cs) => cs!.channel?.extraData);
+  Stream<Map<String, dynamic>?>? get extraDataStream {
+    _checkInitialized();
+    return state?.channelStateStream.map((cs) => cs!.channel?.extraData);
+  }
 
   /// The main Stream chat client
   StreamChatClient get client => _client;
@@ -205,14 +249,14 @@ class Channel {
       throw Exception('Error, Message not found');
     }
 
-    final attachments = message.attachments!.where((it) {
+    final attachments = message.attachments.where((it) {
       if (it.uploadState.isSuccess) return false;
       return attachmentIds.contains(it.id);
     });
 
     if (attachments.isEmpty) {
       client.logger.info('No attachments available to upload');
-      if (message.attachments!.every((it) => it.uploadState.isSuccess)) {
+      if (message.attachments.every((it) => it.uploadState.isSuccess)) {
         _messageAttachmentsUploadCompleter.remove(messageId)?.complete(message);
       }
       return Future.value();
@@ -222,9 +266,9 @@ class Channel {
 
     void updateAttachment(Attachment attachment) {
       final index =
-          message.attachments!.indexWhere((it) => it.id == attachment.id);
+          message.attachments.indexWhere((it) => it.id == attachment.id);
       if (index != -1) {
-        message.attachments![index] = attachment;
+        message.attachments[index] = attachment;
         state?.addMessage(message);
       }
     }
@@ -252,13 +296,13 @@ class Channel {
           it.file!,
           onSendProgress: onSendProgress,
           cancelToken: cancelToken,
-        ).then((it) => it!.file!);
+        ).then((it) => it!.file);
       } else {
         future = sendFile(
           it.file!,
           onSendProgress: onSendProgress,
           cancelToken: cancelToken,
-        ).then((it) => it!.file!);
+        ).then((it) => it!.file);
       }
       _cancelableAttachmentUploadRequest[it.id] = cancelToken;
       return future.then((url) {
@@ -288,7 +332,7 @@ class Channel {
         _cancelableAttachmentUploadRequest.remove(it.id);
       });
     })).whenComplete(() {
-      if (message.attachments!.every((it) => it.uploadState.isSuccess)) {
+      if (message.attachments.every((it) => it.uploadState.isSuccess)) {
         _messageAttachmentsUploadCompleter.remove(messageId)?.complete(message);
       }
     });
@@ -313,7 +357,7 @@ class Channel {
       user: _client.state.user,
       quotedMessage: quotedMessage,
       status: MessageSendingStatus.sending,
-      attachments: message.attachments?.map(
+      attachments: message.attachments.map(
         (it) {
           if (it.uploadState.isSuccess) return it;
           return it.copyWith(uploadState: const UploadState.preparing());
@@ -324,7 +368,7 @@ class Channel {
     state?.addMessage(message);
 
     try {
-      if (message.attachments?.any((it) => !it.uploadState.isSuccess) == true) {
+      if (message.attachments.any((it) => !it.uploadState.isSuccess) == true) {
         final attachmentsUploadCompleter = Completer<Message>();
         _messageAttachmentsUploadCompleter[message.id] =
             attachmentsUploadCompleter;
@@ -332,15 +376,15 @@ class Channel {
         // ignore: unawaited_futures
         _uploadAttachments(
           message.id,
-          message.attachments!.map((it) => it.id),
+          message.attachments.map((it) => it.id),
         );
 
         // ignore: parameter_assignments
         message = await attachmentsUploadCompleter.future;
       }
 
-      final response = await _client.sendMessage(message, id, type);
-      state?.addMessage(response.message!);
+      final response = await _client.sendMessage(message, id!, type!);
+      state?.addMessage(response.message);
       return response;
     } catch (error) {
       if (error is DioError && error.type != DioErrorType.response) {
@@ -364,7 +408,7 @@ class Channel {
     message = message.copyWith(
       status: MessageSendingStatus.updating,
       updatedAt: message.updatedAt,
-      attachments: message.attachments?.map(
+      attachments: message.attachments.map(
         (it) {
           if (it.uploadState.isSuccess) return it;
           return it.copyWith(uploadState: const UploadState.preparing());
@@ -375,7 +419,7 @@ class Channel {
     state?.addMessage(message);
 
     try {
-      if (message.attachments?.any((it) => !it.uploadState.isSuccess) == true) {
+      if (message.attachments.any((it) => !it.uploadState.isSuccess) == true) {
         final attachmentsUploadCompleter = Completer<Message>();
         _messageAttachmentsUploadCompleter[message.id] =
             attachmentsUploadCompleter;
@@ -383,7 +427,7 @@ class Channel {
         // ignore: unawaited_futures
         _uploadAttachments(
           message.id,
-          message.attachments!.map((it) => it.id),
+          message.attachments.map((it) => it.id),
         );
 
         // ignore: parameter_assignments
@@ -392,13 +436,11 @@ class Channel {
 
       final response = await _client.updateMessage(message);
 
-      final m = response.message?.copyWith(
+      final m = response.message.copyWith(
         ownReactions: message.ownReactions,
       );
 
-      if (m != null) {
-        state?.addMessage(m);
-      }
+      state?.addMessage(m);
 
       return response;
     } catch (error) {
@@ -489,28 +531,32 @@ class Channel {
     AttachmentFile file, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
-  }) =>
-      _client.sendFile(
-        file,
-        id,
-        type,
-        onSendProgress: onSendProgress,
-        cancelToken: cancelToken,
-      );
+  }) {
+    _checkInitialized();
+    return _client.sendFile(
+      file,
+      id!,
+      type!,
+      onSendProgress: onSendProgress,
+      cancelToken: cancelToken,
+    );
+  }
 
   /// Send an image to this channel
   Future<SendImageResponse?> sendImage(
     AttachmentFile file, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
-  }) =>
-      _client.sendImage(
-        file,
-        id,
-        type,
-        onSendProgress: onSendProgress,
-        cancelToken: cancelToken,
-      );
+  }) {
+    _checkInitialized();
+    return _client.sendImage(
+      file,
+      id!,
+      type!,
+      onSendProgress: onSendProgress,
+      cancelToken: cancelToken,
+    );
+  }
 
   /// A message search.
   Future<SearchMessagesResponse?> search({
@@ -535,15 +581,29 @@ class Channel {
   Future<EmptyResponse?> deleteFile(
     String url, {
     CancelToken? cancelToken,
-  }) =>
-      _client.deleteFile(url, id, type, cancelToken: cancelToken);
+  }) {
+    _checkInitialized();
+    return _client.deleteFile(
+      url,
+      id!,
+      type!,
+      cancelToken: cancelToken,
+    );
+  }
 
   /// Delete an image from this channel
   Future<EmptyResponse?> deleteImage(
     String url, {
     CancelToken? cancelToken,
-  }) =>
-      _client.deleteImage(url, id, type, cancelToken: cancelToken);
+  }) {
+    _checkInitialized();
+    return _client.deleteImage(
+      url,
+      id!,
+      type!,
+      cancelToken: cancelToken,
+    );
+  }
 
   /// Send an event on this channel
   Future<EmptyResponse> sendEvent(Event event) {
@@ -916,9 +976,7 @@ class Channel {
 
     final messages = res.messages;
 
-    if (messages != null) {
-      state?.updateChannelState(ChannelState(messages: messages));
-    }
+    state?.updateChannelState(ChannelState(messages: messages));
 
     return res;
   }
@@ -1198,11 +1256,10 @@ class Channel {
   }
 
   void _checkInitialized() {
-    if (!_initializedCompleter.isCompleted) {
-      throw Exception(
-          "Channel $cid hasn't been initialized yet. Make sure to call .watch()"
-          ' or to instantiate the client using [Channel.fromState]');
-    }
+    assert(
+        !_initializedCompleter.isCompleted,
+        "Channel $cid hasn't been initialized yet. Make sure to call .watch()"
+        ' or to instantiate the client using [Channel.fromState]');
   }
 }
 
@@ -1285,8 +1342,8 @@ class ChannelClientState {
     final expiredAttachmentMessagesId = channelState.messages
         .where((m) =>
             !_updatedMessagesIds.contains(m.id) &&
-            m.attachments?.isNotEmpty == true &&
-            m.attachments?.any((e) {
+            m.attachments.isNotEmpty == true &&
+            m.attachments.any((e) {
                   final url = e.imageUrl ?? e.assetUrl;
                   if (url == null || !url.contains('')) {
                     return false;
@@ -1602,12 +1659,12 @@ class ChannelClientState {
   bool _countMessageAsUnread(Message message) {
     final userId = _channel.client.state.user?.id;
     final userIsMuted = _channel.client.state.user?.mutes.firstWhereOrNull(
-          (m) => m.user?.id == message.user!.id,
+          (m) => m.user.id == message.user?.id,
         ) !=
         null;
     return message.silent != true &&
         message.shadowed != true &&
-        message.user!.id != userId &&
+        message.user?.id != userId &&
         !userIsMuted;
   }
 
diff --git a/packages/stream_chat/lib/src/api/responses.dart b/packages/stream_chat/lib/src/api/responses.dart
index a26fc626..a64cd64e 100644
--- a/packages/stream_chat/lib/src/api/responses.dart
+++ b/packages/stream_chat/lib/src/api/responses.dart
@@ -20,186 +20,194 @@ class _BaseResponse {
 @JsonSerializable(createToJson: false)
 class SyncResponse extends _BaseResponse {
   /// The list of events
-  List<Event>? events;
+  @JsonKey(defaultValue: [])
+  late List<Event> events;
 
   /// Create a new instance from a json
-  static SyncResponse fromJson(Map<String, dynamic>? json) =>
-      _$SyncResponseFromJson(json!);
+  static SyncResponse fromJson(Map<String, dynamic> json) =>
+      _$SyncResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.queryChannels] api call
 @JsonSerializable(createToJson: false)
 class QueryChannelsResponse extends _BaseResponse {
   /// List of channels state returned by the query
-  List<ChannelState>? channels;
+  @JsonKey(defaultValue: [])
+  late List<ChannelState> channels;
 
   /// Create a new instance from a json
-  static QueryChannelsResponse fromJson(Map<String, dynamic>? json) =>
-      _$QueryChannelsResponseFromJson(json!);
+  static QueryChannelsResponse fromJson(Map<String, dynamic> json) =>
+      _$QueryChannelsResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.queryChannels] api call
 @JsonSerializable(createToJson: false)
 class TranslateMessageResponse extends _BaseResponse {
-  /// List of channels state returned by the query
-  TranslatedMessage? message;
+  /// Translated message
+  late TranslatedMessage message;
 
   /// Create a new instance from a json
-  static TranslateMessageResponse fromJson(Map<String, dynamic>? json) =>
-      _$TranslateMessageResponseFromJson(json!);
+  static TranslateMessageResponse fromJson(Map<String, dynamic> json) =>
+      _$TranslateMessageResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.queryChannels] api call
 @JsonSerializable(createToJson: false)
 class QueryMembersResponse extends _BaseResponse {
   /// List of channels state returned by the query
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Create a new instance from a json
-  static QueryMembersResponse fromJson(Map<String, dynamic>? json) =>
-      _$QueryMembersResponseFromJson(json!);
+  static QueryMembersResponse fromJson(Map<String, dynamic> json) =>
+      _$QueryMembersResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.queryUsers] api call
 @JsonSerializable(createToJson: false)
 class QueryUsersResponse extends _BaseResponse {
   /// List of users returned by the query
-  List<User>? users;
+  @JsonKey(defaultValue: [])
+  late List<User> users;
 
   /// Create a new instance from a json
-  static QueryUsersResponse fromJson(Map<String, dynamic>? json) =>
-      _$QueryUsersResponseFromJson(json!);
+  static QueryUsersResponse fromJson(Map<String, dynamic> json) =>
+      _$QueryUsersResponseFromJson(json);
 }
 
 /// Model response for [channel.getReactions] api call
 @JsonSerializable(createToJson: false)
 class QueryReactionsResponse extends _BaseResponse {
   /// List of reactions returned by the query
-  List<Reaction>? reactions;
+  @JsonKey(defaultValue: [])
+  late List<Reaction> reactions;
 
   /// Create a new instance from a json
-  static QueryReactionsResponse fromJson(Map<String, dynamic>? json) =>
-      _$QueryReactionsResponseFromJson(json!);
+  static QueryReactionsResponse fromJson(Map<String, dynamic> json) =>
+      _$QueryReactionsResponseFromJson(json);
 }
 
 /// Model response for [Channel.getReplies] api call
 @JsonSerializable(createToJson: false)
 class QueryRepliesResponse extends _BaseResponse {
   /// List of messages returned by the api call
-  List<Message>? messages;
+  @JsonKey(defaultValue: [])
+  late List<Message> messages;
 
   /// Create a new instance from a json
-  static QueryRepliesResponse fromJson(Map<String, dynamic>? json) =>
-      _$QueryRepliesResponseFromJson(json!);
+  static QueryRepliesResponse fromJson(Map<String, dynamic> json) =>
+      _$QueryRepliesResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.getDevices] api call
 @JsonSerializable(createToJson: false)
 class ListDevicesResponse extends _BaseResponse {
   /// List of user devices
-  List<Device>? devices;
+  @JsonKey(defaultValue: [])
+  late List<Device> devices;
 
   /// Create a new instance from a json
-  static ListDevicesResponse fromJson(Map<String, dynamic>? json) =>
-      _$ListDevicesResponseFromJson(json!);
+  static ListDevicesResponse fromJson(Map<String, dynamic> json) =>
+      _$ListDevicesResponseFromJson(json);
 }
 
 /// Model response for [Channel.sendFile] api call
 @JsonSerializable(createToJson: false)
 class SendFileResponse extends _BaseResponse {
   /// The url of the uploaded file
-  String? file;
+  late String file;
 
   /// Create a new instance from a json
-  static SendFileResponse fromJson(Map<String, dynamic>? json) =>
-      _$SendFileResponseFromJson(json!);
+  static SendFileResponse fromJson(Map<String, dynamic> json) =>
+      _$SendFileResponseFromJson(json);
 }
 
 /// Model response for [Channel.sendImage] api call
 @JsonSerializable(createToJson: false)
 class SendImageResponse extends _BaseResponse {
   /// The url of the uploaded file
-  String? file;
+  late String file;
 
   /// Create a new instance from a json
-  static SendImageResponse fromJson(Map<String, dynamic>? json) =>
-      _$SendImageResponseFromJson(json!);
+  static SendImageResponse fromJson(Map<String, dynamic> json) =>
+      _$SendImageResponseFromJson(json);
 }
 
 /// Model response for [Channel.sendReaction] api call
 @JsonSerializable(createToJson: false)
 class SendReactionResponse extends _BaseResponse {
   /// Message returned by the api call
-  Message? message;
+  late Message message;
 
   /// The reaction created by the api call
-  Reaction? reaction;
+  late Reaction reaction;
 
   /// Create a new instance from a json
-  static SendReactionResponse fromJson(Map<String, dynamic>? json) =>
-      _$SendReactionResponseFromJson(json!);
+  static SendReactionResponse fromJson(Map<String, dynamic> json) =>
+      _$SendReactionResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.connectGuestUser] api call
 @JsonSerializable(createToJson: false)
 class ConnectGuestUserResponse extends _BaseResponse {
   /// Guest user access token
-  String? accessToken;
+  late String accessToken;
 
   /// Guest user
-  User? user;
+  late User user;
 
   /// Create a new instance from a json
-  static ConnectGuestUserResponse fromJson(Map<String, dynamic>? json) =>
-      _$ConnectGuestUserResponseFromJson(json!);
+  static ConnectGuestUserResponse fromJson(Map<String, dynamic> json) =>
+      _$ConnectGuestUserResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.updateUser] api call
 @JsonSerializable(createToJson: false)
 class UpdateUsersResponse extends _BaseResponse {
   /// Updated users
-  Map<String, User>? users;
+  @JsonKey(defaultValue: {})
+  late Map<String, User> users;
 
   /// Create a new instance from a json
-  static UpdateUsersResponse fromJson(Map<String, dynamic>? json) =>
-      _$UpdateUsersResponseFromJson(json!);
+  static UpdateUsersResponse fromJson(Map<String, dynamic> json) =>
+      _$UpdateUsersResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.updateMessage] api call
 @JsonSerializable(createToJson: false)
 class UpdateMessageResponse extends _BaseResponse {
   /// Message returned by the api call
-  Message? message;
+  late Message message;
 
   /// Create a new instance from a json
-  static UpdateMessageResponse fromJson(Map<String, dynamic>? json) =>
-      _$UpdateMessageResponseFromJson(json!);
+  static UpdateMessageResponse fromJson(Map<String, dynamic> json) =>
+      _$UpdateMessageResponseFromJson(json);
 }
 
 /// Model response for [Channel.sendMessage] api call
 @JsonSerializable(createToJson: false)
 class SendMessageResponse extends _BaseResponse {
   /// Message returned by the api call
-  Message? message;
+  late Message message;
 
   /// Create a new instance from a json
-  static SendMessageResponse fromJson(Map<String, dynamic>? json) =>
-      _$SendMessageResponseFromJson(json!);
+  static SendMessageResponse fromJson(Map<String, dynamic> json) =>
+      _$SendMessageResponseFromJson(json);
 }
 
 /// Model response for [StreamChatClient.getMessage] api call
 @JsonSerializable(createToJson: false)
 class GetMessageResponse extends _BaseResponse {
   /// Message returned by the api call
-  Message? message;
+  late Message message;
 
   /// Channel of the message
   ChannelModel? channel;
 
   /// Create a new instance from a json
-  static GetMessageResponse fromJson(Map<String, dynamic>? json) {
-    final res = _$GetMessageResponseFromJson(json!);
-    final jsonChannel = res.message?.extraData?.remove('channel');
+  static GetMessageResponse fromJson(Map<String, dynamic> json) {
+    final res = _$GetMessageResponseFromJson(json);
+    final jsonChannel = res.message.extraData.remove('channel');
     if (jsonChannel != null) {
       res.channel = ChannelModel.fromJson(jsonChannel);
     }
@@ -211,29 +219,31 @@ class GetMessageResponse extends _BaseResponse {
 @JsonSerializable(createToJson: false)
 class SearchMessagesResponse extends _BaseResponse {
   /// List of messages returned by the api call
-  List<GetMessageResponse>? results;
+  @JsonKey(defaultValue: [])
+  late List<GetMessageResponse> results;
 
   /// Create a new instance from a json
-  static SearchMessagesResponse fromJson(Map<String, dynamic>? json) =>
-      _$SearchMessagesResponseFromJson(json!);
+  static SearchMessagesResponse fromJson(Map<String, dynamic> json) =>
+      _$SearchMessagesResponseFromJson(json);
 }
 
 /// Model response for [Channel.getMessagesById] api call
 @JsonSerializable(createToJson: false)
 class GetMessagesByIdResponse extends _BaseResponse {
   /// Message returned by the api call
-  List<Message>? messages;
+  @JsonKey(defaultValue: [])
+  late List<Message> messages;
 
   /// Create a new instance from a json
-  static GetMessagesByIdResponse fromJson(Map<String, dynamic>? json) =>
-      _$GetMessagesByIdResponseFromJson(json!);
+  static GetMessagesByIdResponse fromJson(Map<String, dynamic> json) =>
+      _$GetMessagesByIdResponseFromJson(json);
 }
 
 /// Model response for [Channel.update] api call
 @JsonSerializable(createToJson: false)
 class UpdateChannelResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
   List<Member>? members;
@@ -242,56 +252,58 @@ class UpdateChannelResponse extends _BaseResponse {
   Message? message;
 
   /// Create a new instance from a json
-  static UpdateChannelResponse fromJson(Map<String, dynamic>? json) =>
-      _$UpdateChannelResponseFromJson(json!);
+  static UpdateChannelResponse fromJson(Map<String, dynamic> json) =>
+      _$UpdateChannelResponseFromJson(json);
 }
 
 /// Model response for [Channel.updatePartial] api call
 @JsonSerializable(createToJson: false)
 class PartialUpdateChannelResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
   List<Member>? members;
 
   /// Create a new instance from a json
-  static PartialUpdateChannelResponse fromJson(Map<String, dynamic>? json) =>
-      _$PartialUpdateChannelResponseFromJson(json!);
+  static PartialUpdateChannelResponse fromJson(Map<String, dynamic> json) =>
+      _$PartialUpdateChannelResponseFromJson(json);
 }
 
 /// Model response for [Channel.inviteMembers] api call
 @JsonSerializable(createToJson: false)
 class InviteMembersResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Message returned by the api call
   Message? message;
 
   /// Create a new instance from a json
-  static InviteMembersResponse fromJson(Map<String, dynamic>? json) =>
-      _$InviteMembersResponseFromJson(json!);
+  static InviteMembersResponse fromJson(Map<String, dynamic> json) =>
+      _$InviteMembersResponseFromJson(json);
 }
 
 /// Model response for [Channel.removeMembers] api call
 @JsonSerializable(createToJson: false)
 class RemoveMembersResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Message returned by the api call
   Message? message;
 
   /// Create a new instance from a json
-  static RemoveMembersResponse fromJson(Map<String, dynamic>? json) =>
-      _$RemoveMembersResponseFromJson(json!);
+  static RemoveMembersResponse fromJson(Map<String, dynamic> json) =>
+      _$RemoveMembersResponseFromJson(json);
 }
 
 /// Model response for [Channel.sendAction] api call
@@ -301,86 +313,93 @@ class SendActionResponse extends _BaseResponse {
   Message? message;
 
   /// Create a new instance from a json
-  static SendActionResponse fromJson(Map<String, dynamic>? json) =>
-      _$SendActionResponseFromJson(json!);
+  static SendActionResponse fromJson(Map<String, dynamic> json) =>
+      _$SendActionResponseFromJson(json);
 }
 
 /// Model response for [Channel.addMembers] api call
 @JsonSerializable(createToJson: false)
 class AddMembersResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Message returned by the api call
   Message? message;
 
   /// Create a new instance from a json
-  static AddMembersResponse fromJson(Map<String, dynamic>? json) =>
-      _$AddMembersResponseFromJson(json!);
+  static AddMembersResponse fromJson(Map<String, dynamic> json) =>
+      _$AddMembersResponseFromJson(json);
 }
 
 /// Model response for [Channel.acceptInvite] api call
 @JsonSerializable(createToJson: false)
 class AcceptInviteResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Message returned by the api call
   Message? message;
 
   /// Create a new instance from a json
-  static AcceptInviteResponse fromJson(Map<String, dynamic>? json) =>
-      _$AcceptInviteResponseFromJson(json!);
+  static AcceptInviteResponse fromJson(Map<String, dynamic> json) =>
+      _$AcceptInviteResponseFromJson(json);
 }
 
 /// Model response for [Channel.rejectInvite] api call
 @JsonSerializable(createToJson: false)
 class RejectInviteResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Message returned by the api call
   Message? message;
 
   /// Create a new instance from a json
-  static RejectInviteResponse fromJson(Map<String, dynamic>? json) =>
-      _$RejectInviteResponseFromJson(json!);
+  static RejectInviteResponse fromJson(Map<String, dynamic> json) =>
+      _$RejectInviteResponseFromJson(json);
 }
 
 /// Model response for empty responses
 @JsonSerializable(createToJson: false)
 class EmptyResponse extends _BaseResponse {
   /// Create a new instance from a json
-  static EmptyResponse fromJson(Map<String, dynamic>? json) =>
-      _$EmptyResponseFromJson(json!);
+  static EmptyResponse fromJson(Map<String, dynamic> json) =>
+      _$EmptyResponseFromJson(json);
 }
 
 /// Model response for [Channel.query] api call
 @JsonSerializable(createToJson: false)
 class ChannelStateResponse extends _BaseResponse {
   /// Updated channel
-  ChannelModel? channel;
+  late ChannelModel channel;
 
   /// List of messages returned by the api call
-  List<Message>? messages;
+  @JsonKey(defaultValue: [])
+  late List<Message> messages;
 
   /// Channel members
-  List<Member>? members;
+  @JsonKey(defaultValue: [])
+  late List<Member> members;
 
   /// Number of users watching the channel
-  int? watcherCount;
+  @JsonKey(defaultValue: 0)
+  late int watcherCount;
 
   /// List of read states
-  List<Read>? read;
+  @JsonKey(defaultValue: [])
+  late List<Read> read;
 
   /// Create a new instance from a json
   static ChannelStateResponse fromJson(Map<String, dynamic> json) =>
diff --git a/packages/stream_chat/lib/src/api/responses.g.dart b/packages/stream_chat/lib/src/api/responses.g.dart
index e1363d0c..2358593d 100644
--- a/packages/stream_chat/lib/src/api/responses.g.dart
+++ b/packages/stream_chat/lib/src/api/responses.g.dart
@@ -10,8 +10,9 @@ SyncResponse _$SyncResponseFromJson(Map<String, dynamic> json) {
   return SyncResponse()
     ..duration = json['duration'] as String?
     ..events = (json['events'] as List<dynamic>?)
-        ?.map((e) => Event.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Event.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 QueryChannelsResponse _$QueryChannelsResponseFromJson(
@@ -19,33 +20,35 @@ QueryChannelsResponse _$QueryChannelsResponseFromJson(
   return QueryChannelsResponse()
     ..duration = json['duration'] as String?
     ..channels = (json['channels'] as List<dynamic>?)
-        ?.map((e) => ChannelState.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => ChannelState.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 TranslateMessageResponse _$TranslateMessageResponseFromJson(
     Map<String, dynamic> json) {
   return TranslateMessageResponse()
     ..duration = json['duration'] as String?
-    ..message = json['message'] == null
-        ? null
-        : TranslatedMessage.fromJson(json['message'] as Map<String, dynamic>);
+    ..message =
+        TranslatedMessage.fromJson(json['message'] as Map<String, dynamic>);
 }
 
 QueryMembersResponse _$QueryMembersResponseFromJson(Map<String, dynamic> json) {
   return QueryMembersResponse()
     ..duration = json['duration'] as String?
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 QueryUsersResponse _$QueryUsersResponseFromJson(Map<String, dynamic> json) {
   return QueryUsersResponse()
     ..duration = json['duration'] as String?
     ..users = (json['users'] as List<dynamic>?)
-        ?.map((e) => User.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => User.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 QueryReactionsResponse _$QueryReactionsResponseFromJson(
@@ -53,90 +56,82 @@ QueryReactionsResponse _$QueryReactionsResponseFromJson(
   return QueryReactionsResponse()
     ..duration = json['duration'] as String?
     ..reactions = (json['reactions'] as List<dynamic>?)
-        ?.map((e) => Reaction.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Reaction.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 QueryRepliesResponse _$QueryRepliesResponseFromJson(Map<String, dynamic> json) {
   return QueryRepliesResponse()
     ..duration = json['duration'] as String?
     ..messages = (json['messages'] as List<dynamic>?)
-        ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 ListDevicesResponse _$ListDevicesResponseFromJson(Map<String, dynamic> json) {
   return ListDevicesResponse()
     ..duration = json['duration'] as String?
     ..devices = (json['devices'] as List<dynamic>?)
-        ?.map((e) => Device.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Device.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 SendFileResponse _$SendFileResponseFromJson(Map<String, dynamic> json) {
   return SendFileResponse()
     ..duration = json['duration'] as String?
-    ..file = json['file'] as String?;
+    ..file = json['file'] as String;
 }
 
 SendImageResponse _$SendImageResponseFromJson(Map<String, dynamic> json) {
   return SendImageResponse()
     ..duration = json['duration'] as String?
-    ..file = json['file'] as String?;
+    ..file = json['file'] as String;
 }
 
 SendReactionResponse _$SendReactionResponseFromJson(Map<String, dynamic> json) {
   return SendReactionResponse()
     ..duration = json['duration'] as String?
-    ..message = json['message'] == null
-        ? null
-        : Message.fromJson(json['message'] as Map<String, dynamic>)
-    ..reaction = json['reaction'] == null
-        ? null
-        : Reaction.fromJson(json['reaction'] as Map<String, dynamic>);
+    ..message = Message.fromJson(json['message'] as Map<String, dynamic>)
+    ..reaction = Reaction.fromJson(json['reaction'] as Map<String, dynamic>);
 }
 
 ConnectGuestUserResponse _$ConnectGuestUserResponseFromJson(
     Map<String, dynamic> json) {
   return ConnectGuestUserResponse()
     ..duration = json['duration'] as String?
-    ..accessToken = json['access_token'] as String?
-    ..user = json['user'] == null
-        ? null
-        : User.fromJson(json['user'] as Map<String, dynamic>);
+    ..accessToken = json['access_token'] as String
+    ..user = User.fromJson(json['user'] as Map<String, dynamic>);
 }
 
 UpdateUsersResponse _$UpdateUsersResponseFromJson(Map<String, dynamic> json) {
   return UpdateUsersResponse()
     ..duration = json['duration'] as String?
     ..users = (json['users'] as Map<String, dynamic>?)?.map(
-      (k, e) => MapEntry(k, User.fromJson(e as Map<String, dynamic>)),
-    );
+          (k, e) => MapEntry(k, User.fromJson(e as Map<String, dynamic>)),
+        ) ??
+        {};
 }
 
 UpdateMessageResponse _$UpdateMessageResponseFromJson(
     Map<String, dynamic> json) {
   return UpdateMessageResponse()
     ..duration = json['duration'] as String?
-    ..message = json['message'] == null
-        ? null
-        : Message.fromJson(json['message'] as Map<String, dynamic>);
+    ..message = Message.fromJson(json['message'] as Map<String, dynamic>);
 }
 
 SendMessageResponse _$SendMessageResponseFromJson(Map<String, dynamic> json) {
   return SendMessageResponse()
     ..duration = json['duration'] as String?
-    ..message = json['message'] == null
-        ? null
-        : Message.fromJson(json['message'] as Map<String, dynamic>);
+    ..message = Message.fromJson(json['message'] as Map<String, dynamic>);
 }
 
 GetMessageResponse _$GetMessageResponseFromJson(Map<String, dynamic> json) {
   return GetMessageResponse()
     ..duration = json['duration'] as String?
-    ..message = json['message'] == null
-        ? null
-        : Message.fromJson(json['message'] as Map<String, dynamic>)
+    ..message = Message.fromJson(json['message'] as Map<String, dynamic>)
     ..channel = json['channel'] == null
         ? null
         : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>);
@@ -147,8 +142,9 @@ SearchMessagesResponse _$SearchMessagesResponseFromJson(
   return SearchMessagesResponse()
     ..duration = json['duration'] as String?
     ..results = (json['results'] as List<dynamic>?)
-        ?.map((e) => GetMessageResponse.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => GetMessageResponse.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 GetMessagesByIdResponse _$GetMessagesByIdResponseFromJson(
@@ -156,17 +152,16 @@ GetMessagesByIdResponse _$GetMessagesByIdResponseFromJson(
   return GetMessagesByIdResponse()
     ..duration = json['duration'] as String?
     ..messages = (json['messages'] as List<dynamic>?)
-        ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
 
 UpdateChannelResponse _$UpdateChannelResponseFromJson(
     Map<String, dynamic> json) {
   return UpdateChannelResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
         ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
         .toList()
@@ -179,9 +174,7 @@ PartialUpdateChannelResponse _$PartialUpdateChannelResponseFromJson(
     Map<String, dynamic> json) {
   return PartialUpdateChannelResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
         ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
         .toList();
@@ -191,12 +184,11 @@ InviteMembersResponse _$InviteMembersResponseFromJson(
     Map<String, dynamic> json) {
   return InviteMembersResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..message = json['message'] == null
         ? null
         : Message.fromJson(json['message'] as Map<String, dynamic>);
@@ -206,12 +198,11 @@ RemoveMembersResponse _$RemoveMembersResponseFromJson(
     Map<String, dynamic> json) {
   return RemoveMembersResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..message = json['message'] == null
         ? null
         : Message.fromJson(json['message'] as Map<String, dynamic>);
@@ -228,12 +219,11 @@ SendActionResponse _$SendActionResponseFromJson(Map<String, dynamic> json) {
 AddMembersResponse _$AddMembersResponseFromJson(Map<String, dynamic> json) {
   return AddMembersResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..message = json['message'] == null
         ? null
         : Message.fromJson(json['message'] as Map<String, dynamic>);
@@ -242,12 +232,11 @@ AddMembersResponse _$AddMembersResponseFromJson(Map<String, dynamic> json) {
 AcceptInviteResponse _$AcceptInviteResponseFromJson(Map<String, dynamic> json) {
   return AcceptInviteResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..message = json['message'] == null
         ? null
         : Message.fromJson(json['message'] as Map<String, dynamic>);
@@ -256,12 +245,11 @@ AcceptInviteResponse _$AcceptInviteResponseFromJson(Map<String, dynamic> json) {
 RejectInviteResponse _$RejectInviteResponseFromJson(Map<String, dynamic> json) {
   return RejectInviteResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..message = json['message'] == null
         ? null
         : Message.fromJson(json['message'] as Map<String, dynamic>);
@@ -274,17 +262,18 @@ EmptyResponse _$EmptyResponseFromJson(Map<String, dynamic> json) {
 ChannelStateResponse _$ChannelStateResponseFromJson(Map<String, dynamic> json) {
   return ChannelStateResponse()
     ..duration = json['duration'] as String?
-    ..channel = json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
+    ..channel = ChannelModel.fromJson(json['channel'] as Map<String, dynamic>)
     ..messages = (json['messages'] as List<dynamic>?)
-        ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
-        .toList()
+            ?.map((e) => Message.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
     ..members = (json['members'] as List<dynamic>?)
-        ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
-        .toList()
-    ..watcherCount = json['watcher_count'] as int?
+            ?.map((e) => Member.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        []
+    ..watcherCount = json['watcher_count'] as int? ?? 0
     ..read = (json['read'] as List<dynamic>?)
-        ?.map((e) => Read.fromJson(e as Map<String, dynamic>))
-        .toList();
+            ?.map((e) => Read.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [];
 }
diff --git a/packages/stream_chat/lib/src/attachment_file_uploader.dart b/packages/stream_chat/lib/src/attachment_file_uploader.dart
index 70976d40..7b90f0c9 100644
--- a/packages/stream_chat/lib/src/attachment_file_uploader.dart
+++ b/packages/stream_chat/lib/src/attachment_file_uploader.dart
@@ -1,8 +1,8 @@
 import 'package:dio/dio.dart';
 import 'package:stream_chat/src/api/responses.dart';
 import 'package:stream_chat/src/client.dart';
-import 'package:stream_chat/src/models/attachment_file.dart';
 import 'package:stream_chat/src/extensions/string_extension.dart';
+import 'package:stream_chat/src/models/attachment_file.dart';
 
 /// Class responsible for uploading images and files to a given channel
 abstract class AttachmentFileUploader {
@@ -13,8 +13,8 @@ abstract class AttachmentFileUploader {
   /// and cancel the request using [cancelToken]
   Future<SendImageResponse> sendImage(
     AttachmentFile image,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   });
@@ -26,8 +26,8 @@ abstract class AttachmentFileUploader {
   /// and cancel the request using [cancelToken]
   Future<SendFileResponse> sendFile(
     AttachmentFile file,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   });
@@ -38,8 +38,8 @@ abstract class AttachmentFileUploader {
   /// Optionally, cancel the request using [cancelToken]
   Future<EmptyResponse> deleteImage(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   });
 
@@ -49,8 +49,8 @@ abstract class AttachmentFileUploader {
   /// Optionally, cancel the request using [cancelToken]
   Future<EmptyResponse> deleteFile(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   });
 }
@@ -65,8 +65,8 @@ class StreamAttachmentFileUploader implements AttachmentFileUploader {
   @override
   Future<SendImageResponse> sendImage(
     AttachmentFile file,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   }) async {
@@ -102,8 +102,8 @@ class StreamAttachmentFileUploader implements AttachmentFileUploader {
   @override
   Future<SendFileResponse> sendFile(
     AttachmentFile file,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   }) async {
@@ -139,8 +139,8 @@ class StreamAttachmentFileUploader implements AttachmentFileUploader {
   @override
   Future<EmptyResponse> deleteImage(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   }) async {
     final response = await _client.delete(
@@ -154,8 +154,8 @@ class StreamAttachmentFileUploader implements AttachmentFileUploader {
   @override
   Future<EmptyResponse> deleteFile(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   }) async {
     final response = await _client.delete(
diff --git a/packages/stream_chat/lib/src/client.dart b/packages/stream_chat/lib/src/client.dart
index 46eb21af..fa007456 100644
--- a/packages/stream_chat/lib/src/client.dart
+++ b/packages/stream_chat/lib/src/client.dart
@@ -82,7 +82,7 @@ class StreamChatClient {
     this.tokenProvider,
     this.baseURL = _defaultBaseURL,
     this.logLevel = Level.WARNING,
-    this.logHandlerFunction,
+    LogHandlerFunction? logHandlerFunction,
     Duration connectTimeout = const Duration(seconds: 6),
     Duration receiveTimeout = const Duration(seconds: 6),
     Dio? httpClient,
@@ -103,7 +103,7 @@ class StreamChatClient {
 
     state = ClientState(this);
 
-    _setupLogger();
+    _setupLogger(logHandlerFunction);
     _setupDio(httpClient, receiveTimeout, connectTimeout);
 
     logger.info('instantiating new client');
@@ -134,7 +134,7 @@ class StreamChatClient {
   RetryPolicy? get retryPolicy => _retryPolicy;
 
   /// This client state
-  late final ClientState state;
+  late ClientState state;
 
   /// By default the Chat client will write all messages with level Warn or
   /// Error to stdout.
@@ -170,7 +170,7 @@ class StreamChatClient {
   /// final client = StreamChatClient("stream-chat-api-key",
   /// logHandlerFunction: myLogHandlerFunction);
   ///```
-  LogHandlerFunction? logHandlerFunction;
+  late LogHandlerFunction logHandlerFunction;
 
   /// Your project Stream Chat api key.
   /// Find your API keys here https://getstream.io/dashboard/
@@ -371,14 +371,14 @@ class StreamChatClient {
   ) =>
       Logger.detached(name)
         ..level = logLevel
-        ..onRecord.listen(logHandlerFunction ?? _getDefaultLogHandler());
+        ..onRecord.listen(logHandlerFunction);
 
-  void _setupLogger() {
+  void _setupLogger(LogHandlerFunction? logHandlerFunction) {
     logger.level = logLevel;
 
-    logHandlerFunction ??= _getDefaultLogHandler();
+    this.logHandlerFunction = logHandlerFunction ?? _getDefaultLogHandler();
 
-    logger.onRecord.listen(logHandlerFunction);
+    logger.onRecord.listen(this.logHandlerFunction);
 
     logger.info('logger setup');
   }
@@ -618,15 +618,15 @@ class StreamChatClient {
         SyncResponse.fromJson,
       );
 
-      res.events!.sort((a, b) => a.createdAt!.compareTo(b.createdAt!));
+      res.events.sort((a, b) => a.createdAt!.compareTo(b.createdAt!));
 
-      res.events!.forEach((element) {
+      res.events.forEach((element) {
         logger
           ..fine('element.type: ${element.type}')
           ..fine('element.message.text: ${element.message?.text}');
       });
 
-      res.events!.forEach(handleEvent);
+      res.events.forEach(handleEvent);
 
       await _chatPersistenceClient?.updateLastSyncAt(DateTime.now());
       _synced = true;
@@ -740,7 +740,7 @@ class StreamChatClient {
       QueryChannelsResponse.fromJson,
     );
 
-    if ((res.channels ?? []).isEmpty && paginationParams.offset == 0) {
+    if (res.channels.isEmpty && paginationParams.offset == 0) {
       logger.warning(
         '''
         We could not find any channel for this query.
@@ -750,7 +750,7 @@ class StreamChatClient {
       return <Channel>[];
     }
 
-    final channels = res.channels!;
+    final channels = res.channels;
 
     final users = channels
         .expand((it) => it.members)
@@ -759,7 +759,7 @@ class StreamChatClient {
 
     state._updateUsers(users);
 
-    logger.info('Got ${res.channels?.length} channels from api');
+    logger.info('Got ${res.channels.length} channels from api');
 
     final updateData = _mapChannelStateToChannel(channels);
 
@@ -1053,7 +1053,7 @@ class StreamChatClient {
       QueryUsersResponse.fromJson,
     );
 
-    state._updateUsers(response.users!);
+    state._updateUsers(response.users);
 
     return response;
   }
@@ -1100,8 +1100,8 @@ class StreamChatClient {
   /// Send a [file] to the [channelId] of type [channelType]
   Future<SendFileResponse> sendFile(
     AttachmentFile file,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   }) =>
@@ -1116,8 +1116,8 @@ class StreamChatClient {
   /// Send a [image] to the [channelId] of type [channelType]
   Future<SendImageResponse> sendImage(
     AttachmentFile image,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     ProgressCallback? onSendProgress,
     CancelToken? cancelToken,
   }) =>
@@ -1132,8 +1132,8 @@ class StreamChatClient {
   /// Delete a file from this channel
   Future<EmptyResponse> deleteFile(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   }) =>
       attachmentFileUploader!.deleteFile(
@@ -1146,8 +1146,8 @@ class StreamChatClient {
   /// Delete an image from this channel
   Future<EmptyResponse> deleteImage(
     String url,
-    String? channelId,
-    String? channelType, {
+    String channelId,
+    String channelType, {
     CancelToken? cancelToken,
   }) =>
       attachmentFileUploader!.deleteImage(
@@ -1327,7 +1327,10 @@ class StreamChatClient {
 
   /// Sends the message to the given channel
   Future<SendMessageResponse> sendMessage(
-      Message message, String? channelId, String? channelType) async {
+    Message message,
+    String channelId,
+    String channelType,
+  ) async {
     final response = await post(
       '/channels/$channelType/$channelId/message',
       data: {'message': message.toJson()},
diff --git a/packages/stream_chat/lib/src/models/action.dart b/packages/stream_chat/lib/src/models/action.dart
index b91f1e13..16a307e7 100644
--- a/packages/stream_chat/lib/src/models/action.dart
+++ b/packages/stream_chat/lib/src/models/action.dart
@@ -6,22 +6,29 @@ part 'action.g.dart';
 @JsonSerializable()
 class Action {
   /// Constructor used for json serialization
-  Action({this.name, this.style, this.text, this.type, this.value});
+  Action({
+    required this.name,
+    this.style = 'default',
+    required this.text,
+    required this.type,
+    this.value,
+  });
 
   /// Create a new instance from a json
   factory Action.fromJson(Map<String, dynamic> json) => _$ActionFromJson(json);
 
   /// The name of the action
-  final String? name;
+  final String name;
 
   /// The style of the action
-  final String? style;
+  @JsonKey(defaultValue: 'default')
+  final String style;
 
   /// The test of the action
-  final String? text;
+  final String text;
 
   /// The type of the action
-  final String? type;
+  final String type;
 
   /// The value of the action
   final String? value;
diff --git a/packages/stream_chat/lib/src/models/action.g.dart b/packages/stream_chat/lib/src/models/action.g.dart
index 770298c7..9ae999ed 100644
--- a/packages/stream_chat/lib/src/models/action.g.dart
+++ b/packages/stream_chat/lib/src/models/action.g.dart
@@ -8,10 +8,10 @@ part of 'action.dart';
 
 Action _$ActionFromJson(Map<String, dynamic> json) {
   return Action(
-    name: json['name'] as String?,
-    style: json['style'] as String?,
-    text: json['text'] as String?,
-    type: json['type'] as String?,
+    name: json['name'] as String,
+    style: json['style'] as String? ?? 'default',
+    text: json['text'] as String,
+    type: json['type'] as String,
     value: json['value'] as String?,
   );
 }
diff --git a/packages/stream_chat/lib/src/models/attachment.dart b/packages/stream_chat/lib/src/models/attachment.dart
index 877c292d..fd91454a 100644
--- a/packages/stream_chat/lib/src/models/attachment.dart
+++ b/packages/stream_chat/lib/src/models/attachment.dart
@@ -15,7 +15,7 @@ class Attachment extends Equatable {
   /// Constructor used for json serialization
   Attachment({
     String? id,
-    String? type,
+    this.type,
     this.titleLink,
     String? title,
     this.thumbUrl,
@@ -32,14 +32,14 @@ class Attachment extends Equatable {
     this.authorLink,
     this.authorIcon,
     this.assetUrl,
-    this.actions,
+    List<Action>? actions,
     this.extraData,
     this.file,
     UploadState? uploadState,
   })  : id = id ?? const Uuid().v4(),
         title = title ?? file?.name,
-        type = type ?? '',
-        localUri = file?.path != null ? Uri.parse(file!.path!) : null {
+        localUri = file?.path != null ? Uri.parse(file!.path!) : null,
+        actions = actions ?? [] {
     this.uploadState = uploadState ??
         ((assetUrl != null || imageUrl != null)
             ? const UploadState.success()
@@ -58,7 +58,7 @@ class Attachment extends Equatable {
 
   ///The attachment type based on the URL resource. This can be: audio,
   ///image or video
-  final String type;
+  final String? type;
 
   ///The link to which the attachment message points to.
   final String? titleLink;
@@ -98,7 +98,8 @@ class Attachment extends Equatable {
   final String? assetUrl;
 
   /// Actions from a command
-  final List<Action>? actions;
+  @JsonKey(defaultValue: [])
+  final List<Action> actions;
 
   final Uri? localUri;
 
@@ -106,7 +107,7 @@ class Attachment extends Equatable {
   final AttachmentFile? file;
 
   /// The current upload state of the attachment
-  late final UploadState? uploadState;
+  late final UploadState uploadState;
 
   /// Map of custom channel extraData
   @JsonKey(includeIfNull: false)
@@ -149,13 +150,13 @@ class Attachment extends Equatable {
   ];
 
   /// Serialize to json
-  Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
-      _$AttachmentToJson(this), topLevelFields)
-    ..removeWhere((key, value) => dbSpecificTopLevelFields.contains(key));
+  Map<String, dynamic> toJson() =>
+      Serialization.moveFromExtraDataToRoot(_$AttachmentToJson(this))
+        ..removeWhere((key, value) => dbSpecificTopLevelFields.contains(key));
 
   /// Serialize to db data
-  Map<String, dynamic> toData() => Serialization.moveFromExtraDataToRoot(
-      _$AttachmentToJson(this), topLevelFields + dbSpecificTopLevelFields);
+  Map<String, dynamic> toData() =>
+      Serialization.moveFromExtraDataToRoot(_$AttachmentToJson(this));
 
   Attachment copyWith({
     String? id,
diff --git a/packages/stream_chat/lib/src/models/attachment.g.dart b/packages/stream_chat/lib/src/models/attachment.g.dart
index acee04fa..b7a7304d 100644
--- a/packages/stream_chat/lib/src/models/attachment.g.dart
+++ b/packages/stream_chat/lib/src/models/attachment.g.dart
@@ -27,8 +27,9 @@ Attachment _$AttachmentFromJson(Map<String, dynamic> json) {
     authorIcon: json['author_icon'] as String?,
     assetUrl: json['asset_url'] as String?,
     actions: (json['actions'] as List<dynamic>?)
-        ?.map((e) => Action.fromJson(e as Map<String, dynamic>))
-        .toList(),
+            ?.map((e) => Action.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [],
     extraData: json['extra_data'] as Map<String, dynamic>?,
     file: json['file'] == null
         ? null
@@ -40,9 +41,7 @@ Attachment _$AttachmentFromJson(Map<String, dynamic> json) {
 }
 
 Map<String, dynamic> _$AttachmentToJson(Attachment instance) {
-  final val = <String, dynamic>{
-    'type': instance.type,
-  };
+  final val = <String, dynamic>{};
 
   void writeNotNull(String key, dynamic value) {
     if (value != null) {
@@ -50,6 +49,7 @@ Map<String, dynamic> _$AttachmentToJson(Attachment instance) {
     }
   }
 
+  writeNotNull('type', instance.type);
   writeNotNull('title_link', instance.titleLink);
   writeNotNull('title', instance.title);
   writeNotNull('thumb_url', instance.thumbUrl);
@@ -66,9 +66,9 @@ Map<String, dynamic> _$AttachmentToJson(Attachment instance) {
   writeNotNull('author_link', instance.authorLink);
   writeNotNull('author_icon', instance.authorIcon);
   writeNotNull('asset_url', instance.assetUrl);
-  writeNotNull('actions', instance.actions?.map((e) => e.toJson()).toList());
+  val['actions'] = instance.actions.map((e) => e.toJson()).toList();
   writeNotNull('file', instance.file?.toJson());
-  writeNotNull('upload_state', instance.uploadState?.toJson());
+  val['upload_state'] = instance.uploadState.toJson();
   writeNotNull('extra_data', instance.extraData);
   val['id'] = instance.id;
   return val;
diff --git a/packages/stream_chat/lib/src/models/attachment_file.dart b/packages/stream_chat/lib/src/models/attachment_file.dart
index fa74d801..d72cecbd 100644
--- a/packages/stream_chat/lib/src/models/attachment_file.dart
+++ b/packages/stream_chat/lib/src/models/attachment_file.dart
@@ -4,7 +4,6 @@ import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:meta/meta.dart';
 
 part 'attachment_file.freezed.dart';
-
 part 'attachment_file.g.dart';
 
 /// Union class to hold various [UploadState] of a attachment.
@@ -14,8 +13,10 @@ class UploadState with _$UploadState {
   const factory UploadState.preparing() = Preparing;
 
   /// InProgress state of the union
-  const factory UploadState.inProgress(
-      {required int uploaded, required int total}) = InProgress;
+  const factory UploadState.inProgress({
+    required int uploaded,
+    required int total,
+  }) = InProgress;
 
   /// Success state of the union
   const factory UploadState.success() = Success;
@@ -62,7 +63,10 @@ class AttachmentFile {
     this.name,
     this.bytes,
     this.size,
-  });
+  }) : assert(
+          path != null || bytes != null,
+          'Either path or bytes should be != null',
+        );
 
   /// Create a new instance from a json
   factory AttachmentFile.fromJson(Map<String, dynamic> json) =>
diff --git a/packages/stream_chat/lib/src/models/channel_config.dart b/packages/stream_chat/lib/src/models/channel_config.dart
index 1500aaf2..9ba36e4f 100644
--- a/packages/stream_chat/lib/src/models/channel_config.dart
+++ b/packages/stream_chat/lib/src/models/channel_config.dart
@@ -1,5 +1,6 @@
 import 'package:json_annotation/json_annotation.dart';
 import 'package:stream_chat/src/models/command.dart';
+
 part 'channel_config.g.dart';
 
 /// The class that contains the information about the configuration of a channel
@@ -7,75 +8,85 @@ part 'channel_config.g.dart';
 class ChannelConfig {
   /// Constructor used for json serialization
   ChannelConfig({
-    this.automod,
-    this.commands,
-    this.connectEvents,
-    this.createdAt,
-    this.updatedAt,
-    this.maxMessageLength,
-    this.messageRetention,
-    this.mutes,
-    this.name,
-    this.reactions,
-    this.readEvents,
-    this.replies,
-    this.search,
-    this.typingEvents,
-    this.uploads,
-    this.urlEnrichment,
-  });
+    this.automod = 'flag',
+    this.commands = const [],
+    this.connectEvents = false,
+    DateTime? createdAt,
+    DateTime? updatedAt,
+    this.maxMessageLength = 0,
+    this.messageRetention = '',
+    this.mutes = false,
+    this.reactions = false,
+    this.readEvents = false,
+    this.replies = false,
+    this.search = false,
+    this.typingEvents = false,
+    this.uploads = false,
+    this.urlEnrichment = false,
+  })  : createdAt = createdAt ?? DateTime.now(),
+        updatedAt = updatedAt ?? DateTime.now();
 
   /// Create a new instance from a json
   factory ChannelConfig.fromJson(Map<String, dynamic> json) =>
       _$ChannelConfigFromJson(json);
 
   /// Moderation configuration
-  final String? automod;
+  @JsonKey(defaultValue: 'flag')
+  final String automod;
 
   /// List of available commands
-  final List<Command>? commands;
+  @JsonKey(defaultValue: [])
+  final List<Command> commands;
 
   /// True if the channel should send connect events
-  final bool? connectEvents;
+  @JsonKey(defaultValue: false)
+  final bool connectEvents;
 
   /// Date of channel creation
-  final DateTime? createdAt;
+  final DateTime createdAt;
 
   /// Date of last channel update
-  final DateTime? updatedAt;
+  final DateTime updatedAt;
 
   /// Max channel message length
-  final int? maxMessageLength;
+  @JsonKey(defaultValue: 0)
+  final int maxMessageLength;
 
   /// Duration of message retention
-  final String? messageRetention;
+  @JsonKey(defaultValue: '')
+  final String messageRetention;
 
   /// True if users can be muted
-  final bool? mutes;
-
-  /// Name of the channel
-  final String? name;
+  @JsonKey(defaultValue: false)
+  final bool mutes;
 
   /// True if reaction are active for this channel
-  final bool? reactions;
+  @JsonKey(defaultValue: false)
+  final bool reactions;
 
   /// True if readEvents are active for this channel
-  final bool? readEvents;
+  @JsonKey(defaultValue: false)
+  final bool readEvents;
 
   /// True if reply message are active for this channel
-  final bool? replies;
+  @JsonKey(defaultValue: false)
+  final bool replies;
 
   /// True if it's possible to perform a search in this channel
-  final bool? search;
+  @JsonKey(defaultValue: false)
+  final bool search;
 
   /// True if typing events should be sent for this channel
-  final bool? typingEvents;
+  @JsonKey(defaultValue: false)
+  final bool typingEvents;
 
   /// True if it's possible to upload files to this channel
-  final bool? uploads;
+  @JsonKey(defaultValue: false)
+  final bool uploads;
 
   /// True if urls appears as attachments
-  final bool? urlEnrichment;
+  @JsonKey(defaultValue: false)
+  final bool urlEnrichment;
 
   /// Serialize to json
   Map<String, dynamic> toJson() => _$ChannelConfigToJson(this);
diff --git a/packages/stream_chat/lib/src/models/channel_config.g.dart b/packages/stream_chat/lib/src/models/channel_config.g.dart
index 41cd0cd2..723281c0 100644
--- a/packages/stream_chat/lib/src/models/channel_config.g.dart
+++ b/packages/stream_chat/lib/src/models/channel_config.g.dart
@@ -8,42 +8,41 @@ part of 'channel_config.dart';
 
 ChannelConfig _$ChannelConfigFromJson(Map<String, dynamic> json) {
   return ChannelConfig(
-    automod: json['automod'] as String?,
+    automod: json['automod'] as String? ?? 'flag',
     commands: (json['commands'] as List<dynamic>?)
-        ?.map((e) => Command.fromJson(e as Map<String, dynamic>))
-        .toList(),
-    connectEvents: json['connect_events'] as bool?,
+            ?.map((e) => Command.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [],
+    connectEvents: json['connect_events'] as bool? ?? false,
     createdAt: json['created_at'] == null
         ? null
         : DateTime.parse(json['created_at'] as String),
     updatedAt: json['updated_at'] == null
         ? null
         : DateTime.parse(json['updated_at'] as String),
-    maxMessageLength: json['max_message_length'] as int?,
-    messageRetention: json['message_retention'] as String?,
-    mutes: json['mutes'] as bool?,
-    name: json['name'] as String?,
-    reactions: json['reactions'] as bool?,
-    readEvents: json['read_events'] as bool?,
-    replies: json['replies'] as bool?,
-    search: json['search'] as bool?,
-    typingEvents: json['typing_events'] as bool?,
-    uploads: json['uploads'] as bool?,
-    urlEnrichment: json['url_enrichment'] as bool?,
+    maxMessageLength: json['max_message_length'] as int? ?? 0,
+    messageRetention: json['message_retention'] as String? ?? '',
+    mutes: json['mutes'] as bool? ?? false,
+    reactions: json['reactions'] as bool? ?? false,
+    readEvents: json['read_events'] as bool? ?? false,
+    replies: json['replies'] as bool? ?? false,
+    search: json['search'] as bool? ?? false,
+    typingEvents: json['typing_events'] as bool? ?? false,
+    uploads: json['uploads'] as bool? ?? false,
+    urlEnrichment: json['url_enrichment'] as bool? ?? false,
   );
 }
 
 Map<String, dynamic> _$ChannelConfigToJson(ChannelConfig instance) =>
     <String, dynamic>{
       'automod': instance.automod,
-      'commands': instance.commands?.map((e) => e.toJson()).toList(),
+      'commands': instance.commands.map((e) => e.toJson()).toList(),
       'connect_events': instance.connectEvents,
-      'created_at': instance.createdAt?.toIso8601String(),
-      'updated_at': instance.updatedAt?.toIso8601String(),
+      'created_at': instance.createdAt.toIso8601String(),
+      'updated_at': instance.updatedAt.toIso8601String(),
       'max_message_length': instance.maxMessageLength,
       'message_retention': instance.messageRetention,
       'mutes': instance.mutes,
-      'name': instance.name,
       'reactions': instance.reactions,
       'read_events': instance.readEvents,
       'replies': instance.replies,
diff --git a/packages/stream_chat/lib/src/models/channel_model.dart b/packages/stream_chat/lib/src/models/channel_model.dart
index edd373ae..d68edbde 100644
--- a/packages/stream_chat/lib/src/models/channel_model.dart
+++ b/packages/stream_chat/lib/src/models/channel_model.dart
@@ -10,9 +10,9 @@ part 'channel_model.g.dart';
 class ChannelModel {
   /// Constructor used for json serialization
   ChannelModel({
-    this.id,
-    this.type,
-    this.cid = '',
+    String? id,
+    String? type,
+    String? cid,
     ChannelConfig? config,
     this.createdBy,
     this.frozen = false,
@@ -25,7 +25,14 @@ class ChannelModel {
     this.team,
   })  : config = config ?? ChannelConfig(),
         createdAt = createdAt ?? DateTime.now(),
-        updatedAt = updatedAt ?? DateTime.now();
+        updatedAt = updatedAt ?? DateTime.now(),
+        assert(
+          cid != null || (id != null && type != null),
+          'provide either a cid or an id and type',
+        ),
+        id = id ?? cid!.split(':')[1],
+        type = type ?? cid!.split(':')[0],
+        cid = cid ?? '$type:$id';
 
   /// Create a new instance from a json
   factory ChannelModel.fromJson(Map<String, dynamic> json) =>
@@ -33,10 +40,10 @@ class ChannelModel {
           Serialization.moveToExtraDataFromRoot(json, topLevelFields));
 
   /// The id of this channel
-  final String? id;
+  final String id;
 
   /// The type of this channel
-  final String? type;
+  final String type;
 
   /// The cid of this channel
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
@@ -107,7 +114,6 @@ class ChannelModel {
   /// Serialize to json
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
         _$ChannelModelToJson(this),
-        topLevelFields,
       );
 
   /// Creates a copy of [ChannelModel] with specified attributes overridden.
diff --git a/packages/stream_chat/lib/src/models/channel_model.g.dart b/packages/stream_chat/lib/src/models/channel_model.g.dart
index 58a9b61e..e71112b6 100644
--- a/packages/stream_chat/lib/src/models/channel_model.g.dart
+++ b/packages/stream_chat/lib/src/models/channel_model.g.dart
@@ -10,7 +10,7 @@ ChannelModel _$ChannelModelFromJson(Map<String, dynamic> json) {
   return ChannelModel(
     id: json['id'] as String?,
     type: json['type'] as String?,
-    cid: json['cid'] as String,
+    cid: json['cid'] as String?,
     config: json['config'] == null
         ? null
         : ChannelConfig.fromJson(json['config'] as Map<String, dynamic>),
diff --git a/packages/stream_chat/lib/src/models/command.dart b/packages/stream_chat/lib/src/models/command.dart
index c8df72fd..5ba0043c 100644
--- a/packages/stream_chat/lib/src/models/command.dart
+++ b/packages/stream_chat/lib/src/models/command.dart
@@ -7,9 +7,9 @@ part 'command.g.dart';
 class Command {
   /// Constructor used for json serialization
   Command({
-    this.name,
-    this.description,
-    this.args,
+    required this.name,
+    required this.description,
+    required this.args,
   });
 
   /// Create a new instance from a json
@@ -17,13 +17,13 @@ class Command {
       _$CommandFromJson(json);
 
   /// The name of the command
-  final String? name;
+  final String name;
 
   /// The description explaining the command
-  final String? description;
+  final String description;
 
   /// The arguments of the command
-  final String? args;
+  final String args;
 
   /// Serialize to json
   Map<String, dynamic> toJson() => _$CommandToJson(this);
diff --git a/packages/stream_chat/lib/src/models/command.g.dart b/packages/stream_chat/lib/src/models/command.g.dart
index 1ce00415..cf8be971 100644
--- a/packages/stream_chat/lib/src/models/command.g.dart
+++ b/packages/stream_chat/lib/src/models/command.g.dart
@@ -8,9 +8,9 @@ part of 'command.dart';
 
 Command _$CommandFromJson(Map<String, dynamic> json) {
   return Command(
-    name: json['name'] as String?,
-    description: json['description'] as String?,
-    args: json['args'] as String?,
+    name: json['name'] as String,
+    description: json['description'] as String,
+    args: json['args'] as String,
   );
 }
 
diff --git a/packages/stream_chat/lib/src/models/device.dart b/packages/stream_chat/lib/src/models/device.dart
index 24dcb678..5dc98d25 100644
--- a/packages/stream_chat/lib/src/models/device.dart
+++ b/packages/stream_chat/lib/src/models/device.dart
@@ -7,8 +7,8 @@ part 'device.g.dart';
 class Device {
   /// Constructor used for json serialization
   Device({
-    this.id = '',
-    this.pushProvider,
+    required this.id,
+    required this.pushProvider,
   });
 
   /// Create a new instance from a json
@@ -18,7 +18,7 @@ class Device {
   final String id;
 
   /// The notification push provider
-  final String? pushProvider;
+  final String pushProvider;
 
   /// Serialize to json
   Map<String, dynamic> toJson() => _$DeviceToJson(this);
diff --git a/packages/stream_chat/lib/src/models/device.g.dart b/packages/stream_chat/lib/src/models/device.g.dart
index fe65053b..5fcd9435 100644
--- a/packages/stream_chat/lib/src/models/device.g.dart
+++ b/packages/stream_chat/lib/src/models/device.g.dart
@@ -9,7 +9,7 @@ part of 'device.dart';
 Device _$DeviceFromJson(Map<String, dynamic> json) {
   return Device(
     id: json['id'] as String,
-    pushProvider: json['push_provider'] as String?,
+    pushProvider: json['push_provider'] as String,
   );
 }
 
diff --git a/packages/stream_chat/lib/src/models/event.dart b/packages/stream_chat/lib/src/models/event.dart
index 621464b6..52092656 100644
--- a/packages/stream_chat/lib/src/models/event.dart
+++ b/packages/stream_chat/lib/src/models/event.dart
@@ -119,7 +119,6 @@ class Event {
   /// Serialize to json
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
         _$EventToJson(this),
-        topLevelFields,
       );
 
   /// Creates a copy of [Event] with specified attributes overridden.
@@ -217,6 +216,5 @@ class EventChannel extends ChannelModel {
   @override
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
         _$EventChannelToJson(this),
-        topLevelFields,
       );
 }
diff --git a/packages/stream_chat/lib/src/models/member.dart b/packages/stream_chat/lib/src/models/member.dart
index ad5f64c8..49df170c 100644
--- a/packages/stream_chat/lib/src/models/member.dart
+++ b/packages/stream_chat/lib/src/models/member.dart
@@ -13,9 +13,9 @@ class Member {
     this.inviteAcceptedAt,
     this.inviteRejectedAt,
     this.invited = false,
-    this.role = '',
+    this.role,
     this.userId,
-    this.isModerator,
+    this.isModerator = false,
     DateTime? createdAt,
     DateTime? updatedAt,
     this.banned = false,
@@ -45,14 +45,14 @@ class Member {
   final bool invited;
 
   /// The role of the user in the channel
-  @JsonKey(defaultValue: '')
-  final String role;
+  final String? role;
 
   /// The id of the interested user
   final String? userId;
 
   /// True if the user is a moderator of the channel
-  final bool? isModerator;
+  @JsonKey(defaultValue: false)
+  final bool isModerator;
 
   /// True if the member is banned from the channel
   @JsonKey(defaultValue: false)
diff --git a/packages/stream_chat/lib/src/models/member.g.dart b/packages/stream_chat/lib/src/models/member.g.dart
index 091cb109..a75b458d 100644
--- a/packages/stream_chat/lib/src/models/member.g.dart
+++ b/packages/stream_chat/lib/src/models/member.g.dart
@@ -18,9 +18,9 @@ Member _$MemberFromJson(Map<String, dynamic> json) {
         ? null
         : DateTime.parse(json['invite_rejected_at'] as String),
     invited: json['invited'] as bool? ?? false,
-    role: json['role'] as String? ?? '',
+    role: json['role'] as String?,
     userId: json['user_id'] as String?,
-    isModerator: json['is_moderator'] as bool?,
+    isModerator: json['is_moderator'] as bool? ?? false,
     createdAt: json['created_at'] == null
         ? null
         : DateTime.parse(json['created_at'] as String),
diff --git a/packages/stream_chat/lib/src/models/message.dart b/packages/stream_chat/lib/src/models/message.dart
index b25662c0..03a162c5 100644
--- a/packages/stream_chat/lib/src/models/message.dart
+++ b/packages/stream_chat/lib/src/models/message.dart
@@ -46,12 +46,12 @@ class Message extends Equatable {
   /// Constructor used for json serialization
   Message({
     String? id,
-    this.text = '',
-    this.type = '',
-    this.attachments,
-    this.mentionedUsers,
-    this.silent,
-    this.shadowed,
+    this.text,
+    this.type = 'regular',
+    this.attachments = const [],
+    this.mentionedUsers = const [],
+    this.silent = false,
+    this.shadowed = false,
     this.reactionCounts,
     this.reactionScores,
     this.latestReactions,
@@ -70,10 +70,10 @@ class Message extends Equatable {
     this.pinnedAt,
     DateTime? pinExpires,
     this.pinnedBy,
-    this.extraData,
+    this.extraData = const {},
     this.deletedAt,
     this.status = MessageSendingStatus.sent,
-    this.skipPush,
+    this.skipPush = false,
   })  : id = id ?? const Uuid().v4(),
         pinExpires = pinExpires?.toUtc(),
         createdAt = createdAt ?? DateTime.now(),
@@ -88,24 +88,34 @@ class Message extends Equatable {
   final String id;
 
   /// The text of this message
-  final String text;
+  final String? text;
 
   /// The status of a sending message
   @JsonKey(ignore: true)
   final MessageSendingStatus status;
 
   /// The message type
-  @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
+  @JsonKey(
+    includeIfNull: false,
+    toJson: Serialization.readOnly,
+    defaultValue: 'regular',
+  )
   final String type;
 
   /// The list of attachments, either provided by the user or generated from a
   /// command or as a result of URL scraping.
-  @JsonKey(includeIfNull: false)
-  final List<Attachment>? attachments;
+  @JsonKey(
+    includeIfNull: false,
+    defaultValue: [],
+  )
+  final List<Attachment> attachments;
 
   /// The list of user mentioned in the message
-  @JsonKey(toJson: Serialization.userIds)
-  final List<User>? mentionedUsers;
+  @JsonKey(
+    toJson: Serialization.userIds,
+    defaultValue: [],
+  )
+  final List<User> mentionedUsers;
 
   /// A map describing the count of number of every reaction
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
@@ -145,14 +155,20 @@ class Message extends Equatable {
   final bool? showInChannel;
 
   /// If true the message is silent
-  final bool? silent;
+  @JsonKey(defaultValue: false)
+  final bool silent;
 
   /// If true the message will not send a push notification
-  final bool? skipPush;
+  @JsonKey(defaultValue: false)
+  final bool skipPush;
 
   /// If true the message is shadowed
-  @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
-  final bool? shadowed;
+  @JsonKey(
+    includeIfNull: false,
+    toJson: Serialization.readOnly,
+    defaultValue: false,
+  )
+  final bool shadowed;
 
   /// A used command name.
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
@@ -171,7 +187,8 @@ class Message extends Equatable {
   final User? user;
 
   /// If true the message is pinned
-  final bool? pinned;
+  @JsonKey(defaultValue: false)
+  final bool pinned;
 
   /// Reserved field indicating when the message was pinned
   @JsonKey(toJson: Serialization.readOnly)
@@ -187,8 +204,11 @@ class Message extends Equatable {
   final User? pinnedBy;
 
   /// Message custom extraData
-  @JsonKey(includeIfNull: false)
-  final Map<String, dynamic>? extraData;
+  @JsonKey(
+    includeIfNull: false,
+    defaultValue: {},
+  )
+  final Map<String, dynamic> extraData;
 
   /// True if the message is a system info
   bool get isSystem => type == 'system';
@@ -238,7 +258,8 @@ class Message extends Equatable {
 
   /// Serialize to json
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
-      _$MessageToJson(this), topLevelFields);
+        _$MessageToJson(this),
+      );
 
   /// Creates a copy of [Message] with specified attributes overridden.
   Message copyWith({
@@ -408,6 +429,5 @@ class TranslatedMessage extends Message {
   @override
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
         _$TranslatedMessageToJson(this),
-        topLevelFields,
       );
 }
diff --git a/packages/stream_chat/lib/src/models/message.g.dart b/packages/stream_chat/lib/src/models/message.g.dart
index 9dfea3c4..ca094a83 100644
--- a/packages/stream_chat/lib/src/models/message.g.dart
+++ b/packages/stream_chat/lib/src/models/message.g.dart
@@ -9,16 +9,18 @@ part of 'message.dart';
 Message _$MessageFromJson(Map<String, dynamic> json) {
   return Message(
     id: json['id'] as String?,
-    text: json['text'] as String,
-    type: json['type'] as String,
+    text: json['text'] as String?,
+    type: json['type'] as String? ?? 'regular',
     attachments: (json['attachments'] as List<dynamic>?)
-        ?.map((e) => Attachment.fromJson(e as Map<String, dynamic>))
-        .toList(),
+            ?.map((e) => Attachment.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [],
     mentionedUsers: (json['mentioned_users'] as List<dynamic>?)
-        ?.map((e) => User.fromJson(e as Map<String, dynamic>))
-        .toList(),
-    silent: json['silent'] as bool?,
-    shadowed: json['shadowed'] as bool?,
+            ?.map((e) => User.fromJson(e as Map<String, dynamic>))
+            .toList() ??
+        [],
+    silent: json['silent'] as bool? ?? false,
+    shadowed: json['shadowed'] as bool? ?? false,
     reactionCounts: (json['reaction_counts'] as Map<String, dynamic>?)?.map(
       (k, e) => MapEntry(k, e as int),
     ),
@@ -51,7 +53,7 @@ Message _$MessageFromJson(Map<String, dynamic> json) {
     user: json['user'] == null
         ? null
         : User.fromJson(json['user'] as Map<String, dynamic>),
-    pinned: json['pinned'] as bool?,
+    pinned: json['pinned'] as bool? ?? false,
     pinnedAt: json['pinned_at'] == null
         ? null
         : DateTime.parse(json['pinned_at'] as String),
@@ -61,11 +63,11 @@ Message _$MessageFromJson(Map<String, dynamic> json) {
     pinnedBy: json['pinned_by'] == null
         ? null
         : User.fromJson(json['pinned_by'] as Map<String, dynamic>),
-    extraData: json['extra_data'] as Map<String, dynamic>?,
+    extraData: json['extra_data'] as Map<String, dynamic>? ?? {},
     deletedAt: json['deleted_at'] == null
         ? null
         : DateTime.parse(json['deleted_at'] as String),
-    skipPush: json['skip_push'] as bool?,
+    skipPush: json['skip_push'] as bool? ?? false,
   );
 }
 
@@ -82,8 +84,7 @@ Map<String, dynamic> _$MessageToJson(Message instance) {
   }
 
   writeNotNull('type', readonly(instance.type));
-  writeNotNull(
-      'attachments', instance.attachments?.map((e) => e.toJson()).toList());
+  val['attachments'] = instance.attachments.map((e) => e.toJson()).toList();
   val['mentioned_users'] = Serialization.userIds(instance.mentionedUsers);
   writeNotNull('reaction_counts', readonly(instance.reactionCounts));
   writeNotNull('reaction_scores', readonly(instance.reactionScores));
@@ -106,7 +107,7 @@ Map<String, dynamic> _$MessageToJson(Message instance) {
   val['pinned_at'] = readonly(instance.pinnedAt);
   val['pin_expires'] = instance.pinExpires?.toIso8601String();
   val['pinned_by'] = readonly(instance.pinnedBy);
-  writeNotNull('extra_data', instance.extraData);
+  val['extra_data'] = instance.extraData;
   writeNotNull('deleted_at', readonly(instance.deletedAt));
   return val;
 }
diff --git a/packages/stream_chat/lib/src/models/mute.dart b/packages/stream_chat/lib/src/models/mute.dart
index 65300d4a..3ba26230 100644
--- a/packages/stream_chat/lib/src/models/mute.dart
+++ b/packages/stream_chat/lib/src/models/mute.dart
@@ -9,26 +9,31 @@ part 'mute.g.dart';
 @JsonSerializable()
 class Mute {
   /// Constructor used for json serialization
-  Mute({this.user, this.channel, this.createdAt, this.updatedAt});
+  Mute({
+    required this.user,
+    required this.channel,
+    required this.createdAt,
+    required this.updatedAt,
+  });
 
   /// Create a new instance from a json
   factory Mute.fromJson(Map<String, dynamic> json) => _$MuteFromJson(json);
 
   /// The user that performed the muting action
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
-  final User? user;
+  final User user;
 
   /// The target user
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
-  final ChannelModel? channel;
+  final ChannelModel channel;
 
   /// The date in which the use was muted
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
-  final DateTime? createdAt;
+  final DateTime createdAt;
 
   /// The date of the last update
   @JsonKey(includeIfNull: false, toJson: Serialization.readOnly)
-  final DateTime? updatedAt;
+  final DateTime updatedAt;
 
   /// Serialize to json
   Map<String, dynamic> toJson() => _$MuteToJson(this);
diff --git a/packages/stream_chat/lib/src/models/mute.g.dart b/packages/stream_chat/lib/src/models/mute.g.dart
index 652a1bc3..e77b8707 100644
--- a/packages/stream_chat/lib/src/models/mute.g.dart
+++ b/packages/stream_chat/lib/src/models/mute.g.dart
@@ -8,18 +8,10 @@ part of 'mute.dart';
 
 Mute _$MuteFromJson(Map<String, dynamic> json) {
   return Mute(
-    user: json['user'] == null
-        ? null
-        : User.fromJson(json['user'] as Map<String, dynamic>),
-    channel: json['channel'] == null
-        ? null
-        : ChannelModel.fromJson(json['channel'] as Map<String, dynamic>),
-    createdAt: json['created_at'] == null
-        ? null
-        : DateTime.parse(json['created_at'] as String),
-    updatedAt: json['updated_at'] == null
-        ? null
-        : DateTime.parse(json['updated_at'] as String),
+    user: User.fromJson(json['user'] as Map<String, dynamic>),
+    channel: ChannelModel.fromJson(json['channel'] as Map<String, dynamic>),
+    createdAt: DateTime.parse(json['created_at'] as String),
+    updatedAt: DateTime.parse(json['updated_at'] as String),
   );
 }
 
diff --git a/packages/stream_chat/lib/src/models/own_user.dart b/packages/stream_chat/lib/src/models/own_user.dart
index d22f706e..3ce951cf 100644
--- a/packages/stream_chat/lib/src/models/own_user.dart
+++ b/packages/stream_chat/lib/src/models/own_user.dart
@@ -84,5 +84,6 @@ class OwnUser extends User {
   /// Serialize to json
   @override
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
-      _$OwnUserToJson(this), topLevelFields);
+        _$OwnUserToJson(this),
+      );
 }
diff --git a/packages/stream_chat/lib/src/models/reaction.dart b/packages/stream_chat/lib/src/models/reaction.dart
index 767f1057..eefeaebe 100644
--- a/packages/stream_chat/lib/src/models/reaction.dart
+++ b/packages/stream_chat/lib/src/models/reaction.dart
@@ -11,7 +11,7 @@ class Reaction {
   Reaction({
     this.messageId,
     DateTime? createdAt,
-    this.type = '',
+    required this.type,
     required this.user,
     String? userId,
     this.score = 0,
@@ -64,7 +64,8 @@ class Reaction {
 
   /// Serialize to json
   Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
-      _$ReactionToJson(this), topLevelFields);
+        _$ReactionToJson(this),
+      );
 
   /// Creates a copy of [Reaction] with specified attributes overridden.
   Reaction copyWith({
diff --git a/packages/stream_chat/lib/src/models/read.dart b/packages/stream_chat/lib/src/models/read.dart
index ef20eb6e..cbd47dd1 100644
--- a/packages/stream_chat/lib/src/models/read.dart
+++ b/packages/stream_chat/lib/src/models/read.dart
@@ -10,7 +10,7 @@ class Read {
   Read({
     required this.lastRead,
     required this.user,
-    required this.unreadMessages,
+    this.unreadMessages = 0,
   });
 
   /// Create a new instance from a json
diff --git a/packages/stream_chat/lib/src/models/serialization.dart b/packages/stream_chat/lib/src/models/serialization.dart
index 6cd4cfbd..d584912e 100644
--- a/packages/stream_chat/lib/src/models/serialization.dart
+++ b/packages/stream_chat/lib/src/models/serialization.dart
@@ -10,7 +10,7 @@ class Serialization {
   static const Function readOnly = readonly;
 
   /// List of users to list of userIds
-  static List<String?>? userIds(List<User>? users) =>
+  static List<String>? userIds(List<User>? users) =>
       users?.map((u) => u.id).toList();
 
   /// Takes unknown json keys and puts them in the `extra_data` key
@@ -36,7 +36,6 @@ class Serialization {
   /// the json map
   static Map<String, dynamic> moveFromExtraDataToRoot(
     Map<String, dynamic> json,
-    List<String> topLevelFields,
   ) {
     final jsonClone = Map<String, dynamic>.from(json);
     return jsonClone
diff --git a/packages/stream_chat/lib/src/models/user.dart b/packages/stream_chat/lib/src/models/user.dart
index 224e0f20..67fc99f0 100644
--- a/packages/stream_chat/lib/src/models/user.dart
+++ b/packages/stream_chat/lib/src/models/user.dart
@@ -105,8 +105,9 @@ class User {
       other is User && runtimeType == other.runtimeType && id == other.id;
 
   /// Serialize to json
-  Map<String, dynamic> toJson() =>
-      Serialization.moveFromExtraDataToRoot(_$UserToJson(this), topLevelFields);
+  Map<String, dynamic> toJson() => Serialization.moveFromExtraDataToRoot(
+        _$UserToJson(this),
+      );
 
   /// Creates a copy of [User] with specified attributes overridden.
   User copyWith({
diff --git a/packages/stream_chat/test/src/api/channel_test.dart b/packages/stream_chat/test/src/api/channel_test.dart
index 4717f524..e0a29cc8 100644
--- a/packages/stream_chat/test/src/api/channel_test.dart
+++ b/packages/stream_chat/test/src/api/channel_test.dart
@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:dio/dio.dart';
 import 'package:dio/native_imp.dart';
 import 'package:mocktail/mocktail.dart';
@@ -6,11 +8,10 @@ import 'package:stream_chat/src/client.dart';
 import 'package:stream_chat/src/event_type.dart';
 import 'package:stream_chat/src/models/event.dart';
 import 'package:stream_chat/src/models/message.dart';
-import 'package:stream_chat/src/models/reaction.dart';
 import 'package:stream_chat/src/models/own_user.dart';
-import 'package:test/test.dart';
-
+import 'package:stream_chat/src/models/reaction.dart';
 import 'package:stream_chat/stream_chat.dart';
+import 'package:test/test.dart';
 
 class MockDio extends Mock implements DioForNative {}
 
@@ -76,7 +77,7 @@ void main() {
               any(),
               data: any(named: 'data'),
             )).thenAnswer((_) async => Response(
-              data: '{}',
+              data: jsonEncode(ChannelState()),
               statusCode: 200,
               requestOptions: FakeRequestOptions(),
             ));
diff --git a/packages/stream_chat/test/src/client_test.dart b/packages/stream_chat/test/src/client_test.dart
index 4e880bed..c93059d5 100644
--- a/packages/stream_chat/test/src/client_test.dart
+++ b/packages/stream_chat/test/src/client_test.dart
@@ -9,9 +9,9 @@ import 'package:mocktail/mocktail.dart';
 import 'package:stream_chat/src/api/requests.dart';
 import 'package:stream_chat/src/client.dart';
 import 'package:stream_chat/src/exceptions.dart';
+import 'package:stream_chat/src/models/channel_model.dart';
 import 'package:stream_chat/src/models/message.dart';
 import 'package:stream_chat/src/models/user.dart';
-import 'package:stream_chat/src/models/channel_model.dart';
 import 'package:test/test.dart';
 
 class MockDio extends Mock implements DioForNative {}
@@ -748,7 +748,7 @@ void main() {
           ),
         ).thenAnswer(
           (_) async => Response(
-            data: '{}',
+            data: jsonEncode({'message': message}),
             statusCode: 200,
             requestOptions: FakeRequestOptions(),
           ),
@@ -793,7 +793,7 @@ void main() {
 
         when(() => mockDio.get<String>('/messages/$messageId')).thenAnswer(
           (_) async => Response(
-            data: '{}',
+            data: jsonEncode({'message': Message(id: messageId)}),
             statusCode: 200,
             requestOptions: FakeRequestOptions(),
           ),
@@ -1115,7 +1115,7 @@ void main() {
             ),
           ).thenAnswer(
             (_) async => Response(
-              data: '{}',
+              data: jsonEncode({'message': message}),
               statusCode: 200,
               requestOptions: FakeRequestOptions(),
             ),
@@ -1137,7 +1137,7 @@ void main() {
             ),
           ).thenAnswer(
             (_) async => Response(
-              data: '{}',
+              data: jsonEncode({'message': message}),
               statusCode: 200,
               requestOptions: FakeRequestOptions(),
             ),
@@ -1177,7 +1177,7 @@ void main() {
           ),
         ).thenAnswer(
           (_) async => Response(
-            data: '{}',
+            data: jsonEncode({'channel': ChannelModel(cid: 'messaging:test')}),
             statusCode: 200,
             requestOptions: FakeRequestOptions(),
           ),
diff --git a/packages/stream_chat/test/src/models/attachment_test.dart b/packages/stream_chat/test/src/models/attachment_test.dart
index 1ca45132..1342e72e 100644
--- a/packages/stream_chat/test/src/models/attachment_test.dart
+++ b/packages/stream_chat/test/src/models/attachment_test.dart
@@ -1,7 +1,7 @@
 import 'dart:convert';
-import 'package:stream_chat/src/models/attachment.dart';
-import 'package:stream_chat/src/models/action.dart';
 
+import 'package:stream_chat/src/models/action.dart';
+import 'package:stream_chat/src/models/attachment.dart';
 import 'package:test/test.dart';
 
 void main() {
@@ -50,7 +50,7 @@ void main() {
         'https://media0.giphy.com/media/3o7TKnCdBx5cMg0qti/giphy.gif',
       );
       expect(attachment.actions, hasLength(3));
-      expect(attachment.actions![0], isA<Action>());
+      expect(attachment.actions[0], isA<Action>());
     });
 
     test('should serialize to json correctly', () {
@@ -67,7 +67,8 @@ void main() {
           'type': 'image',
           'title': 'soo',
           'title_link':
-              'https://giphy.com/gifs/nrkp3-dance-happy-3o7TKnCdBx5cMg0qti'
+              'https://giphy.com/gifs/nrkp3-dance-happy-3o7TKnCdBx5cMg0qti',
+          'actions': [],
         },
       );
     });
diff --git a/packages/stream_chat/test/src/models/channel_state_test.dart b/packages/stream_chat/test/src/models/channel_state_test.dart
index 98d08596..afe384f5 100644
--- a/packages/stream_chat/test/src/models/channel_state_test.dart
+++ b/packages/stream_chat/test/src/models/channel_state_test.dart
@@ -1,12 +1,12 @@
 import 'dart:convert';
 
-import 'package:test/test.dart';
 import 'package:stream_chat/src/models/channel_config.dart';
 import 'package:stream_chat/src/models/channel_state.dart';
 import 'package:stream_chat/src/models/command.dart';
 import 'package:stream_chat/src/models/message.dart';
 import 'package:stream_chat/src/models/user.dart';
 import 'package:stream_chat/stream_chat.dart';
+import 'package:test/test.dart';
 
 void main() {
   group('src/models/channel_state', () {
@@ -852,7 +852,7 @@ void main() {
       expect(channelState.channel?.config, isA<ChannelConfig>());
       expect(channelState.channel?.config, isNotNull);
       expect(channelState.channel?.config.commands, hasLength(1));
-      expect(channelState.channel?.config.commands![0], isA<Command>());
+      expect(channelState.channel?.config.commands[0], isA<Command>());
       expect(channelState.channel?.lastMessageAt,
           DateTime.parse('2020-01-30T13:43:41.062362Z'));
       expect(channelState.channel?.createdAt,
@@ -902,7 +902,7 @@ void main() {
                 "show_in_channel": null,
                 "mentioned_users": [],
                 "status": "SENT",
-            "skip_push": null,
+                "skip_push": false,
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
@@ -919,7 +919,7 @@ void main() {
                 "show_in_channel": null,
                 "mentioned_users": [],
                 "status": "SENT",
-            "skip_push": null,
+                "skip_push": false,
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
@@ -929,7 +929,7 @@ void main() {
               {
                 "id": "dry-meadow-0-53e6299f-9b97-4a9c-a27e-7e2dde49b7e0",
                 "text": "test message",
-            "skip_push": null,
+                "skip_push": false,
                 "attachments": [],
                 "parent_id": null,
                 "quoted_message": null,
@@ -952,7 +952,7 @@ void main() {
                 "quoted_message_id": null,
                 "show_in_channel": null,
                 "mentioned_users": [],
-            "skip_push": null,
+                "skip_push": false,
                 "status": "SENT",
                 "silent": false,
                 "pinned": false,
@@ -964,7 +964,7 @@ void main() {
                 "id": "dry-meadow-0-64d7970f-ede8-4b31-9738-1bc1756d2bfe",
                 "text": "test",
                 "attachments": [],
-            "skip_push": null,
+                "skip_push": false,
                 "parent_id": null,
                 "quoted_message": null,
                 "quoted_message_id": null,
@@ -982,7 +982,7 @@ void main() {
                 "text": "hi",
                 "attachments": [],
                 "parent_id": null,
-            "skip_push": null,
+                "skip_push": false,
                 "quoted_message": null,
                 "quoted_message_id": null,
                 "show_in_channel": null,
@@ -1000,7 +1000,7 @@ void main() {
                 "attachments": [],
                 "parent_id": null,
                 "quoted_message": null,
-            "skip_push": null,
+                "skip_push": false,
                 "quoted_message_id": null,
                 "show_in_channel": null,
                 "mentioned_users": [],
@@ -1023,7 +1023,7 @@ void main() {
                 "status": "SENT",
                 "silent": false,
                 "pinned": false,
-            "skip_push": null,
+                "skip_push": false,
                 "pinned_at": null,
                 "pin_expires": null,
                 "pinned_by": null
@@ -1041,7 +1041,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1053,7 +1053,7 @@ void main() {
                 "quoted_message": null,
                 "quoted_message_id": null,
                 "show_in_channel": null,
-            "skip_push": null,
+                "skip_push": false,
                 "mentioned_users": [],
                 "status": "SENT",
                 "silent": false,
@@ -1071,7 +1071,7 @@ void main() {
                 "quoted_message_id": null,
                 "show_in_channel": null,
                 "mentioned_users": [],
-            "skip_push": null,
+                "skip_push": false,
                 "status": "SENT",
                 "silent": false,
                 "pinned": false,
@@ -1090,7 +1090,7 @@ void main() {
                 "mentioned_users": [],
                 "status": "SENT",
                 "silent": false,
-            "skip_push": null,
+                "skip_push": false,
                 "pinned": false,
                 "pinned_at": null,
                 "pin_expires": null,
@@ -1100,7 +1100,7 @@ void main() {
                 "id": "icy-recipe-7-935c396e-ddf8-4a9a-951c-0a12fa5bf055",
                 "text": "what are you doing?",
                 "attachments": [],
-            "skip_push": null,
+                "skip_push": false,
                 "parent_id": null,
                 "quoted_message": null,
                 "quoted_message_id": null,
@@ -1118,7 +1118,7 @@ void main() {
                 "text": "👍",
                 "attachments": [],
                 "parent_id": null,
-            "skip_push": null,
+                "skip_push": false,
                 "quoted_message": null,
                 "quoted_message_id": null,
                 "show_in_channel": null,
@@ -1134,7 +1134,7 @@ void main() {
                 "id": "snowy-credit-3-3e0c1a0d-d22f-42ee-b2a1-f9f49477bf21",
                 "text": "sdasas",
                 "attachments": [],
-            "skip_push": null,
+                "skip_push": false,
                 "parent_id": null,
                 "quoted_message": null,
                 "quoted_message_id": null,
@@ -1155,7 +1155,7 @@ void main() {
                 "quoted_message": null,
                 "quoted_message_id": null,
                 "show_in_channel": null,
-            "skip_push": null,
+                "skip_push": false,
                 "mentioned_users": [],
                 "status": "SENT",
                 "silent": false,
@@ -1168,7 +1168,7 @@ void main() {
                 "id": "snowy-credit-3-cfaf0b46-1daa-49c5-947c-b16d6697487d",
                 "text": "nhisagdhsadz",
                 "attachments": [],
-            "skip_push": null,
+                "skip_push": false,
                 "parent_id": null,
                 "quoted_message": null,
                 "quoted_message_id": null,
@@ -1187,7 +1187,7 @@ void main() {
                 "attachments": [],
                 "parent_id": null,
                 "quoted_message": null,
-            "skip_push": null,
+                "skip_push": false,
                 "quoted_message_id": null,
                 "show_in_channel": null,
                 "mentioned_users": [],
@@ -1204,7 +1204,7 @@ void main() {
                 "attachments": [],
                 "parent_id": null,
                 "quoted_message": null,
-            "skip_push": null,
+                "skip_push": false,
                 "quoted_message_id": null,
                 "show_in_channel": null,
                 "mentioned_users": [],
@@ -1212,7 +1212,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1229,7 +1229,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1246,7 +1246,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1263,7 +1263,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1280,7 +1280,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1297,7 +1297,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               },
@@ -1314,7 +1314,7 @@ void main() {
                 "silent": false,
                 "pinned": false,
                 "pinned_at": null,
-            "skip_push": null,
+                "skip_push": false,
                 "pin_expires": null,
                 "pinned_by": null
               }
diff --git a/packages/stream_chat/test/src/models/channel_test.dart b/packages/stream_chat/test/src/models/channel_test.dart
index a48c5a23..01c06fee 100644
--- a/packages/stream_chat/test/src/models/channel_test.dart
+++ b/packages/stream_chat/test/src/models/channel_test.dart
@@ -1,7 +1,7 @@
 import 'dart:convert';
 
-import 'package:test/test.dart';
 import 'package:stream_chat/src/models/channel_model.dart';
+import 'package:test/test.dart';
 
 void main() {
   group('src/models/channel', () {
@@ -9,7 +9,7 @@ void main() {
       {
         "id": "test",
         "type": "livestream",
-        "cid": "test:livestream",
+        "cid": "livestream:test",
         "cats": true,
         "fruit": ["bananas", "apples"]
       }      
@@ -19,7 +19,7 @@ void main() {
       final channel = ChannelModel.fromJson(json.decode(jsonExample));
       expect(channel.id, equals('test'));
       expect(channel.type, equals('livestream'));
-      expect(channel.cid, equals('test:livestream'));
+      expect(channel.cid, equals('livestream:test'));
       expect(channel.extraData!['cats'], equals(true));
       expect(channel.extraData!['fruit'], equals(['bananas', 'apples']));
     });
diff --git a/packages/stream_chat/test/src/models/message_test.dart b/packages/stream_chat/test/src/models/message_test.dart
index a34911cf..ddaed93f 100644
--- a/packages/stream_chat/test/src/models/message_test.dart
+++ b/packages/stream_chat/test/src/models/message_test.dart
@@ -1,10 +1,10 @@
 import 'dart:convert';
 
-import 'package:test/test.dart';
 import 'package:stream_chat/src/models/attachment.dart';
 import 'package:stream_chat/src/models/message.dart';
 import 'package:stream_chat/src/models/reaction.dart';
 import 'package:stream_chat/src/models/user.dart';
+import 'package:test/test.dart';
 
 void main() {
   group('src/models/message', () {
@@ -134,7 +134,7 @@ void main() {
             "id": "4637f7e4-a06b-42db-ba5a-8d8270dd926f",
             "text": "https://giphy.com/gifs/the-lion-king-live-action-5zvN79uTGfLMOVfQaA",
             "silent": false,
-            "skip_push": null,
+            "skip_push": false,
             "attachments": [
               {
                 "type": "video",
@@ -145,10 +145,11 @@ void main() {
                 "og_scrape_url": "https://giphy.com/gifs/the-lion-king-live-action-5zvN79uTGfLMOVfQaA",
                 "image_url": "https://media.giphy.com/media/5zvN79uTGfLMOVfQaA/giphy.gif",
                 "author_name": "GIPHY",
-                "asset_url": "https://media.giphy.com/media/5zvN79uTGfLMOVfQaA/giphy.mp4"
+                "asset_url": "https://media.giphy.com/media/5zvN79uTGfLMOVfQaA/giphy.mp4",
+                "actions": []
               }
             ],
-            "mentioned_users": null,
+            "mentioned_users": [],
             "parent_id": "parentId",
             "quoted_message": null,
             "quoted_message_id": null,
diff --git a/packages/stream_chat_flutter/test/src/message_reactions_modal_test.dart b/packages/stream_chat_flutter/test/src/message_reactions_modal_test.dart
index 044eb693..8745cb45 100644
--- a/packages/stream_chat_flutter/test/src/message_reactions_modal_test.dart
+++ b/packages/stream_chat_flutter/test/src/message_reactions_modal_test.dart
@@ -90,6 +90,7 @@ void main() {
           Reaction(
             messageId: 'test',
             user: User(id: 'testid'),
+            type: 'test',
           ),
         ],
       );