diff --git a/packages/imessage/lib/channel_image.dart b/packages/imessage/lib/channel_image.dart
index 65b23ff..d7b6343 100644
--- a/packages/imessage/lib/channel_image.dart
+++ b/packages/imessage/lib/channel_image.dart
@@ -4,7 +4,7 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart' show Channel;
 import 'package:imessage/utils.dart';
 
 class ChannelImage extends StatelessWidget {
-  const ChannelImage({Key key, @required this.channel, @required this.size})
+  const ChannelImage({Key? key, required this.channel, required this.size})
       : super(key: key);
 
   final Channel channel;
@@ -14,7 +14,7 @@ class ChannelImage extends StatelessWidget {
   Widget build(BuildContext context) {
     final avatarUrl = channel.extraData.containsKey('image') &&
             (channel.extraData['image'] as String).isNotEmpty
-        ? channel.extraData['image'] as String
+        ? channel.extraData['image'] as String?
         : 'https://4.bp.blogspot.com/-Jx21kNqFSTU/UXemtqPhZCI/AAAAAAAAh74/BMGSzpU6F48/s1600/funny-cat-pictures-047-001.jpg';
 
     return CupertinoCircleAvatar(
diff --git a/packages/imessage/lib/channel_list_view.dart b/packages/imessage/lib/channel_list_view.dart
index 89c03b5..9421b6d 100644
--- a/packages/imessage/lib/channel_list_view.dart
+++ b/packages/imessage/lib/channel_list_view.dart
@@ -6,7 +6,7 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart'
     show Channel, StreamChannel;
 
 class ChannelListView extends StatelessWidget {
-  const ChannelListView({Key key, @required this.channels}) : super(key: key);
+  const ChannelListView({Key? key, required this.channels}) : super(key: key);
   final List<Channel> channels;
   @override
   Widget build(BuildContext context) {
@@ -36,10 +36,10 @@ class ChannelListView extends StatelessWidget {
                       child,
                     ) =>
                         SharedAxisTransition(
-                      child: child,
                       animation: animation,
                       secondaryAnimation: secondaryAnimation,
                       transitionType: SharedAxisTransitionType.horizontal,
+                      child: child,
                     ),
                   ),
                 );
diff --git a/packages/imessage/lib/channel_name_text.dart b/packages/imessage/lib/channel_name_text.dart
index e2e8d2b..169bb9d 100644
--- a/packages/imessage/lib/channel_name_text.dart
+++ b/packages/imessage/lib/channel_name_text.dart
@@ -3,8 +3,8 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart' show Channel;
 
 class ChannelNameText extends StatelessWidget {
   const ChannelNameText({
-    Key key,
-    @required this.channel,
+    Key? key,
+    required this.channel,
     this.size = 17,
   }) : super(key: key);
 
@@ -14,7 +14,7 @@ class ChannelNameText extends StatelessWidget {
   @override
   Widget build(BuildContext context) {
     return Text(
-      channel.extraData['name'] as String ?? 'No name',
+      channel.extraData['name'] as String? ?? 'No name',
       style: TextStyle(
         fontSize: size,
         fontWeight: FontWeight.bold,
diff --git a/packages/imessage/lib/channel_page_appbar.dart b/packages/imessage/lib/channel_page_appbar.dart
index f991829..5f44995 100644
--- a/packages/imessage/lib/channel_page_appbar.dart
+++ b/packages/imessage/lib/channel_page_appbar.dart
@@ -2,7 +2,7 @@ import 'package:flutter/cupertino.dart';
 
 class ChannelPageAppBar extends StatelessWidget {
   const ChannelPageAppBar({
-    Key key,
+    Key? key,
   }) : super(key: key);
 
   @override
diff --git a/packages/imessage/lib/channel_preview.dart b/packages/imessage/lib/channel_preview.dart
index 8b8c039..98a16c4 100644
--- a/packages/imessage/lib/channel_preview.dart
+++ b/packages/imessage/lib/channel_preview.dart
@@ -11,19 +11,20 @@ class ChannelPreview extends StatelessWidget {
   final Channel channel;
 
   const ChannelPreview({
-    Key key,
-    @required this.onTap,
-    @required this.channel,
+    Key? key,
+    required this.onTap,
+    required this.channel,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    final lastMessage =
-        channel.state.messages.isNotEmpty ? channel.state.messages.last : null;
+    final lastMessage = channel.state!.messages.isNotEmpty
+        ? channel.state!.messages.last
+        : null;
 
     final prefix = lastMessage?.attachments != null
         ? lastMessage?.attachments //TODO: ugly
-            ?.map((e) {
+            .map((e) {
               if (e.type == 'image') {
                 return '📷 ';
               } else if (e.type == 'video') {
@@ -31,8 +32,8 @@ class ChannelPreview extends StatelessWidget {
               }
               return null;
             })
-            ?.where((e) => e != null)
-            ?.join(' ')
+            .where((e) => e != null)
+            .join(' ')
         : '';
     return GestureDetector(
       onTap: onTap,
@@ -76,9 +77,9 @@ class ChannelPreview extends StatelessWidget {
                           child: Row(
                             children: [
                               Text(
-                                isSameWeek(channel.lastMessageAt)
-                                    ? formatDateSameWeek(channel.lastMessageAt)
-                                    : formatDate(channel.lastMessageAt),
+                                isSameWeek(channel.lastMessageAt!)
+                                    ? formatDateSameWeek(channel.lastMessageAt!)
+                                    : formatDate(channel.lastMessageAt!),
                                 style: TextStyle(
                                   fontSize: 15,
                                   color: CupertinoColors.systemGrey,
diff --git a/packages/imessage/lib/cutom_painter.dart b/packages/imessage/lib/cutom_painter.dart
index 4437fc3..0ed6213 100644
--- a/packages/imessage/lib/cutom_painter.dart
+++ b/packages/imessage/lib/cutom_painter.dart
@@ -2,10 +2,10 @@ import 'package:flutter/cupertino.dart';
 
 class ChatBubble extends CustomPainter {
   final Color color;
-  final Alignment alignment;
+  final Alignment? alignment;
 
   ChatBubble({
-    @required this.color,
+    required this.color,
     this.alignment,
   });
 
diff --git a/packages/imessage/lib/main.dart b/packages/imessage/lib/main.dart
index f235f41..fc7283d 100644
--- a/packages/imessage/lib/main.dart
+++ b/packages/imessage/lib/main.dart
@@ -1,18 +1,7 @@
 import 'package:flutter/cupertino.dart';
 import 'package:intl/date_symbol_data_local.dart';
 import 'package:stream_chat_flutter/stream_chat_flutter.dart'
-    show
-        Channel,
-        ChannelListController,
-        ChannelListCore,
-        ChannelsBloc,
-        LazyLoadScrollView,
-        Level,
-        PaginationParams,
-        SortOption,
-        StreamChatClient,
-        StreamChatCore,
-        User;
+    hide ChannelListView;
 
 import 'package:imessage/channel_list_view.dart';
 
@@ -37,7 +26,7 @@ Future<void> main() async {
 
 class IMessage extends StatelessWidget {
   final StreamChatClient client;
-  IMessage({@required this.client});
+  IMessage({required this.client});
   @override
   Widget build(BuildContext context) {
     initializeDateFormatting('en_US', null);
@@ -52,70 +41,69 @@ class IMessage extends StatelessWidget {
 
 class ChatLoader extends StatelessWidget {
   ChatLoader({
-    Key key,
+    Key? key,
   }) : super(key: key);
 
   final channelListController = ChannelListController();
 
   @override
   Widget build(BuildContext context) {
-    final user = StreamChatCore.of(context).user;
+    final user = StreamChatCore.of(context).user!;
     return CupertinoPageScaffold(
-        child: ChannelsBloc(
-            child: ChannelListCore(
-                channelListController: channelListController,
-                filter: {
-                  'members': {
-                    r'$in': [user.id],
-                  },
-                  'type': {
-                    r'$eq': 'messaging',
-                  },
-                },
-                sort: [SortOption('last_message_at')],
-                pagination: PaginationParams(
-                  limit: 20,
-                ),
-                emptyBuilder: (BuildContext context) {
-                  return Center(
-                    child: Text('Looks like you are not in any channels'),
-                  );
-                },
-                loadingBuilder: (BuildContext context) {
-                  return Center(
-                    child: SizedBox(
-                      height: 100.0,
-                      width: 100.0,
-                      child: CupertinoActivityIndicator(),
-                    ),
-                  );
-                },
-                errorBuilder: (BuildContext context, dynamic error) {
-                  return Center(
-                    child: Text(
-                        'Oh no, something went wrong. Please check your config.'),
-                  );
-                },
-                listBuilder: (
-                  BuildContext context,
-                  List<Channel> channels,
-                ) =>
-                    LazyLoadScrollView(
-                      onEndOfPage: () async {
-                        channelListController.paginateData();
-                      },
-                      child: CustomScrollView(
-                        slivers: [
-                          CupertinoSliverRefreshControl(onRefresh: () async {
-                            channelListController.loadData();
-                          }),
-                          ChannelPageAppBar(),
-                          SliverPadding(
-                            sliver: ChannelListView(channels: channels),
-                            padding: const EdgeInsets.only(top: 16),
-                          )
-                        ],
-                      ),
-                    ))));
+      child: ChannelsBloc(
+        child: ChannelListCore(
+          channelListController: channelListController,
+          filter: Filter.and([
+            Filter.in_('members', [user.id]),
+            Filter.equal('type', 'messaging'),
+          ]),
+          sort: [SortOption('last_message_at')],
+          pagination: PaginationParams(
+            limit: 20,
+          ),
+          emptyBuilder: (BuildContext context) {
+            return Center(
+              child: Text('Looks like you are not in any channels'),
+            );
+          },
+          loadingBuilder: (BuildContext context) {
+            return Center(
+              child: SizedBox(
+                height: 100.0,
+                width: 100.0,
+                child: CupertinoActivityIndicator(),
+              ),
+            );
+          },
+          errorBuilder: (BuildContext context, dynamic error) {
+            return Center(
+              child: Text(
+                  'Oh no, something went wrong. Please check your config.'),
+            );
+          },
+          listBuilder: (
+            BuildContext context,
+            List<Channel> channels,
+          ) =>
+              LazyLoadScrollView(
+            onEndOfPage: () async {
+              return channelListController.paginateData!();
+            },
+            child: CustomScrollView(
+              slivers: [
+                CupertinoSliverRefreshControl(onRefresh: () async {
+                  return channelListController.loadData!();
+                }),
+                ChannelPageAppBar(),
+                SliverPadding(
+                  sliver: ChannelListView(channels: channels),
+                  padding: const EdgeInsets.only(top: 16),
+                )
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
   }
 }
diff --git a/packages/imessage/lib/message_header.dart b/packages/imessage/lib/message_header.dart
index 31ae34b..e8ee94b 100644
--- a/packages/imessage/lib/message_header.dart
+++ b/packages/imessage/lib/message_header.dart
@@ -4,7 +4,7 @@ import 'package:imessage/utils.dart';
 
 class MessageHeader extends StatelessWidget {
   final String rawTimeStamp;
-  const MessageHeader({Key key, @required this.rawTimeStamp}) : super(key: key);
+  const MessageHeader({Key? key, required this.rawTimeStamp}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/packages/imessage/lib/message_input.dart b/packages/imessage/lib/message_input.dart
index 9d9d831..7836498 100644
--- a/packages/imessage/lib/message_input.dart
+++ b/packages/imessage/lib/message_input.dart
@@ -3,11 +3,11 @@ import 'dart:io';
 import 'package:flutter/cupertino.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:stream_chat_flutter/stream_chat_flutter.dart'
-    show Attachment, AttachmentFile, Message, MultipartFile, StreamChannel;
+    show Attachment, AttachmentFile, Message, StreamChannel;
 
 class MessageInput extends StatefulWidget {
   const MessageInput({
-    Key key,
+    Key? key,
   }) : super(key: key);
 
   @override
@@ -16,7 +16,6 @@ class MessageInput extends StatefulWidget {
 
 class _MessageInputState extends State<MessageInput> {
   final textController = TextEditingController();
-  File _image;
   final picker = ImagePicker();
 
   @override
@@ -39,16 +38,25 @@ class _MessageInputState extends State<MessageInput> {
             GestureDetector(
               onTap: () async {
                 final pickedFile =
-                    await picker.getImage(source: ImageSource.gallery);
+                    await (picker.getImage(source: ImageSource.gallery));
+                if (pickedFile == null) {
+                  return;
+                }
                 final bytes = await File(pickedFile.path).readAsBytes();
                 final channel = StreamChannel.of(context).channel;
-                final message =
-                    Message(text: textController.value.text, attachments: [
-                  Attachment(
-                    type: 'image',
-                    file: AttachmentFile(bytes: bytes, path: pickedFile.path),
-                  ),
-                ]);
+                final message = Message(
+                  text: textController.value.text,
+                  attachments: [
+                    Attachment(
+                      type: 'image',
+                      file: AttachmentFile(
+                        bytes: bytes,
+                        path: pickedFile.path,
+                        size: bytes.length,
+                      ),
+                    ),
+                  ],
+                );
                 await channel.sendMessage(message);
               },
               child: Padding(
@@ -68,10 +76,11 @@ class _MessageInputState extends State<MessageInput> {
                 },
                 placeholder: 'Text Message',
                 prefix: Padding(
-                    padding: const EdgeInsets.all(8.0),
-                    child: Text(
-                        "") //trick to add padding around  placeholder iMessage text
-                    ),
+                  padding: const EdgeInsets.all(8.0),
+                  child: Text(
+                    '',
+                  ), //trick to add padding around  placeholder iMessage text
+                ),
                 suffix: GestureDetector(
                   onTap: () async {
                     if (textController.value.text.isNotEmpty) {
diff --git a/packages/imessage/lib/message_list_view.dart b/packages/imessage/lib/message_list_view.dart
index e12572c..b76f506 100644
--- a/packages/imessage/lib/message_list_view.dart
+++ b/packages/imessage/lib/message_list_view.dart
@@ -7,12 +7,12 @@ import 'package:stream_chat_flutter/stream_chat_flutter.dart'
     show Message, StreamChatCore;
 
 class MessageListView extends StatelessWidget {
-  const MessageListView({Key key, this.messages}) : super(key: key);
-  final List<Message> messages;
+  const MessageListView({Key? key, this.messages}) : super(key: key);
+  final List<Message>? messages;
 
   @override
   Widget build(BuildContext context) {
-    final entries = groupBy(messages,
+    final entries = groupBy(messages!,
             (Message message) => message.createdAt.toString().substring(0, 10))
         .entries
         .toList();
@@ -64,8 +64,8 @@ class MessageListView extends StatelessWidget {
   }
 
   bool isReceived(Message message, BuildContext context) {
-    final currentUserId = StreamChatCore.of(context).user.id;
-    return message.user.id == currentUserId;
+    final currentUserId = StreamChatCore.of(context).user!.id;
+    return message.user!.id == currentUserId;
   }
 
   bool isSameDay(Message message) =>
diff --git a/packages/imessage/lib/message_page.dart b/packages/imessage/lib/message_page.dart
index 01b555e..f64eb66 100644
--- a/packages/imessage/lib/message_page.dart
+++ b/packages/imessage/lib/message_page.dart
@@ -53,7 +53,7 @@ class MessagePage extends StatelessWidget {
               },
               messageListBuilder: (context, messages) => LazyLoadScrollView(
                     onStartOfPage: () async {
-                      messageListController.paginateData();
+                      await messageListController.paginateData!();
                     },
                     child: MessageListView(
                       messages: messages,
diff --git a/packages/imessage/lib/message_widget.dart b/packages/imessage/lib/message_widget.dart
index 494e9d2..8fa6638 100644
--- a/packages/imessage/lib/message_widget.dart
+++ b/packages/imessage/lib/message_widget.dart
@@ -1,8 +1,7 @@
 import 'package:cached_network_image/cached_network_image.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:imessage/cutom_painter.dart';
-import 'package:stream_chat_flutter/stream_chat_flutter.dart'
-    show Message, AttachmentUploadStateBuilder;
+import 'package:stream_chat_flutter/stream_chat_flutter.dart' show Message;
 
 class MessageWidget extends StatelessWidget {
   final Alignment alignment;
@@ -11,16 +10,16 @@ class MessageWidget extends StatelessWidget {
   final Color messageColor;
 
   const MessageWidget(
-      {Key key,
-      @required this.alignment,
-      @required this.message,
-      @required this.color,
-      @required this.messageColor})
+      {Key? key,
+      required this.alignment,
+      required this.message,
+      required this.color,
+      required this.messageColor})
       : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    if (message.attachments?.isNotEmpty == true &&
+    if (message.attachments.isNotEmpty == true &&
         message.attachments.first.type == 'image') {
       return MessageImage(
           color: color, message: message, messageColor: messageColor);
@@ -36,10 +35,10 @@ class MessageWidget extends StatelessWidget {
 
 class MessageImage extends StatelessWidget {
   const MessageImage({
-    Key key,
-    @required this.color,
-    @required this.message,
-    @required this.messageColor,
+    Key? key,
+    required this.color,
+    required this.message,
+    required this.messageColor,
   }) : super(key: key);
 
   final Color color;
@@ -61,23 +60,23 @@ class MessageImage extends StatelessWidget {
                   children: [
                     if (message.attachments.first.file != null)
                       Image.memory(
-                        message.attachments.first.file.bytes,
+                        message.attachments.first.file!.bytes!,
                         fit: BoxFit.cover,
                       )
                     else
                       CachedNetworkImage(
                         imageUrl: message.attachments.first.thumbUrl ??
                             message.attachments.first.imageUrl ??
-                            message.attachments.first.assetUrl,
+                            message.attachments.first.assetUrl!,
                       ),
-                    if (message.attachments.first?.title != null)
+                    if (message.attachments.first.title != null)
                       Padding(
                         padding: const EdgeInsets.all(8.0),
-                        child: Text(message.attachments.first.title,
+                        child: Text(message.attachments.first.title!,
                             style: TextStyle(color: messageColor)),
                       ),
                     message.attachments.first.pretext != null
-                        ? Text(message.attachments.first.pretext)
+                        ? Text(message.attachments.first.pretext!)
                         : Container()
                   ],
                 ),
@@ -92,7 +91,7 @@ class MessageImage extends StatelessWidget {
         child: Container(
             color: color,
             child: CachedNetworkImage(
-              imageUrl: message.attachments.first.thumbUrl,
+              imageUrl: message.attachments.first.thumbUrl!,
             )),
       );
     }
@@ -101,11 +100,11 @@ class MessageImage extends StatelessWidget {
 
 class MessageText extends StatelessWidget {
   const MessageText({
-    Key key,
-    @required this.alignment,
-    @required this.color,
-    @required this.message,
-    @required this.messageColor,
+    Key? key,
+    required this.alignment,
+    required this.color,
+    required this.message,
+    required this.messageColor,
   }) : super(key: key);
 
   final Alignment alignment;
@@ -133,7 +132,7 @@ class MessageText extends StatelessWidget {
                   child: Padding(
                     padding: const EdgeInsets.all(4.0),
                     child: Text(
-                      message.text,
+                      message.text!,
                       style: TextStyle(color: messageColor),
                     ),
                   ),
diff --git a/packages/imessage/lib/utils.dart b/packages/imessage/lib/utils.dart
index 4600512..6487b35 100644
--- a/packages/imessage/lib/utils.dart
+++ b/packages/imessage/lib/utils.dart
@@ -26,24 +26,26 @@ bool isSameWeek(DateTime timestamp) =>
     DateTime.now().difference(timestamp).inDays < 7;
 
 class CupertinoCircleAvatar extends StatelessWidget {
-  final String url;
-  final double size;
-  const CupertinoCircleAvatar({Key key, this.url, this.size}) : super(key: key);
+  final String? url;
+  final double? size;
+  const CupertinoCircleAvatar({Key? key, this.url, this.size})
+      : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return ClipRRect(
-      borderRadius: BorderRadius.circular(size / 2),
+      borderRadius: BorderRadius.circular(size! / 2),
       child: CachedNetworkImage(
-          imageUrl: url,
+          imageUrl: url!,
           height: size,
           width: size,
           fit: BoxFit.cover,
           errorWidget: (context, url, error) {
             //TODO: this crash the app when getting 404 and in debug mode, see :https://github.com/Baseflow/flutter_cached_network_image/issues/504
             return CachedNetworkImage(
-                imageUrl:
-                    "https://4.bp.blogspot.com/-Jx21kNqFSTU/UXemtqPhZCI/AAAAAAAAh74/BMGSzpU6F48/s1600/funny-cat-pictures-047-001.jpg");
+              imageUrl:
+                  'https://4.bp.blogspot.com/-Jx21kNqFSTU/UXemtqPhZCI/AAAAAAAAh74/BMGSzpU6F48/s1600/funny-cat-pictures-047-001.jp',
+            );
           }),
     );
   }
@@ -51,18 +53,18 @@ class CupertinoCircleAvatar extends StatelessWidget {
 
 class Divider extends StatelessWidget {
   const Divider({
-    Key key,
+    Key? key,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Expanded(
       child: Align(
+        alignment: Alignment.bottomCenter,
         child: Container(
           height: 1,
           color: CupertinoColors.systemGrey5,
         ),
-        alignment: Alignment.bottomCenter,
       ),
     );
   }
diff --git a/packages/imessage/pubspec.yaml b/packages/imessage/pubspec.yaml
index 62e7507..9d05f4c 100644
--- a/packages/imessage/pubspec.yaml
+++ b/packages/imessage/pubspec.yaml
@@ -18,16 +18,16 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
-  intl: ^0.16.1
-  stream_chat_flutter: ^1.3.0-beta
-  animations: ^1.0.0+5
-  collection: ^1.14.13
-  cached_network_image: ^2.0.0-rc
+  intl: ^0.17.0
+  stream_chat_flutter: ^2.0.0-nullsafety.3
+  animations: ^2.0.0
+  collection: ^1.15.0
+  cached_network_image: ^3.0.0
 
 
   # The following adds the Cupertino Icons font to your application.