diff --git a/lib/i18n/app_en.arb b/lib/i18n/app_en.arb
index 9cd0cf1..e7a0c28 100644
--- a/lib/i18n/app_en.arb
+++ b/lib/i18n/app_en.arb
@@ -28,6 +28,7 @@
   "birthday": "Birthday",
   "password": "Password",
   "next": "Next",
+  "join": "Join",
   "edit": "Edit",
   "apply": "Apply",
   "delete": "Delete",
@@ -95,6 +96,9 @@
   "chatDetail": "Chat Details",
   "chatMember": "Member",
   "chatNotifySetting": "Notify Settings",
+  "chatChannelUnavailable": "Channel Unavailable",
+  "chatChannelUnavailableCaptionWithRealm": "You didn't join the channel, but looks like you able to join to, would you want to have a try?",
+  "chatChannelUnavailableCaption": "You didn't join the channel, so you cannot access the information of this channel.",
   "chatChannelUsage": "Channel",
   "chatChannelUsageCaption": "Channel is place to talk with people, one or a lot.",
   "chatChannelOrganize": "Organize a channel",
diff --git a/lib/i18n/app_zh.arb b/lib/i18n/app_zh.arb
index 7525bd3..faa71ff 100644
--- a/lib/i18n/app_zh.arb
+++ b/lib/i18n/app_zh.arb
@@ -2,6 +2,7 @@
   "appName": "Solar Network",
   "explore": "探索",
   "chat": "聊天",
+  "realm": "领域",
   "account": "账号",
   "riskDetection": "风险监测",
   "signIn": "登录",
@@ -27,6 +28,7 @@
   "birthday": "生日",
   "password": "密码",
   "next": "下一步",
+  "join": "加入",
   "edit": "编辑",
   "delete": "删除",
   "action": "操作",
@@ -74,10 +76,27 @@
   "postEditNotify": "你正在修改一个已经发布了的帖子。",
   "reactionAdded": "你的反应已被添加。",
   "reactionRemoved": "你的反应已被移除。",
+  "realmNew": "新领域",
+  "realmNewCreate": "创建新领域",
+  "realmNewJoin": "加入现有领域",
+  "realmUsage": "领域",
+  "realmUsageCaption": "领域是一个地方给你来组织帖子、文章、聊天频道的，好好利用领域打造一个绝妙的专属于你的社区吧！",
+  "realmEstablish": "部署领域",
+  "realmEditNotify": "你正在修改一个现有领域……",
+  "realmAliasLabel": "领域别名",
+  "realmNameLabel": "领域名称",
+  "realmDescriptionLabel": "领域简介",
+  "realmPublicLabel": "公共领域",
+  "realmCommunityLabel": "社区领域（任何人均可加入）",
+  "realmMember": "成员",
+  "realmManage": "领域管理",
   "chatNew": "新聊天",
   "chatDetail": "聊天详情",
   "chatMember": "成员",
   "chatNotifySetting": "通知设定",
+  "chatChannelUnavailable": "频道不可用",
+  "chatChannelUnavailableCaptionWithRealm": "你没加入该频道，但是看起来你能加入本频道，你想加入吗？",
+  "chatChannelUnavailableCaption": "你没加入该频道，所以你无法读取本频道的信息。",
   "chatNewCreate": "新建频道",
   "chatNewJoin": "加入已有频道",
   "chatChannelUsage": "频道",
diff --git a/lib/models/channel.dart b/lib/models/channel.dart
index b3df743..f4b0290 100644
--- a/lib/models/channel.dart
+++ b/lib/models/channel.dart
@@ -15,6 +15,8 @@ class Channel {
   int accountId;
   int? realmId;
 
+  bool isAvailable = false;
+
   Channel({
     required this.id,
     required this.createdAt,
diff --git a/lib/providers/chat.dart b/lib/providers/chat.dart
index 893c25c..23b9694 100644
--- a/lib/providers/chat.dart
+++ b/lib/providers/chat.dart
@@ -44,14 +44,13 @@ class ChatProvider extends ChangeNotifier {
     return channel;
   }
 
-  Future<Channel> fetchChannel(String alias, String realm) async {
-    final Client client = Client();
-
-    var uri = getRequestUri('messaging', '/api/channels/$realm/$alias');
-    var res = await client.get(uri);
-    if (res.statusCode == 200) {
+  Future<Channel> fetchChannel(AuthProvider auth, String alias, String realm) async {
+    var uri = getRequestUri('messaging', '/api/channels/$realm/$alias/availability');
+    var res = await auth.client!.get(uri);
+    if (res.statusCode == 200 || res.statusCode == 403) {
       final result = jsonDecode(utf8.decode(res.bodyBytes));
       focusChannel = Channel.fromJson(result);
+      focusChannel?.isAvailable = res.statusCode == 200;
       notifyListeners();
       return focusChannel!;
     } else {
diff --git a/lib/screens/chat/chat.dart b/lib/screens/chat/chat.dart
index 3f93b71..ffe5b8b 100644
--- a/lib/screens/chat/chat.dart
+++ b/lib/screens/chat/chat.dart
@@ -16,6 +16,7 @@ import 'package:solian/widgets/chat/chat_maintainer.dart';
 import 'package:solian/widgets/chat/message.dart';
 import 'package:solian/widgets/chat/message_action.dart';
 import 'package:solian/widgets/chat/message_editor.dart';
+import 'package:solian/widgets/exts.dart';
 import 'package:solian/widgets/scaffold.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 
@@ -27,6 +28,7 @@ class ChatScreen extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final auth = context.read<AuthProvider>();
     final chat = context.watch<ChatProvider>();
 
     return IndentScaffold(
@@ -39,12 +41,12 @@ class ChatScreen extends StatelessWidget {
                 call: chat.ongoingCall,
                 channel: chat.focusChannel!,
                 realm: realm,
-                onUpdate: () => chat.fetchChannel(chat.focusChannel!.alias, realm),
+                onUpdate: () => chat.fetchChannel(auth, chat.focusChannel!.alias, realm),
               ),
               ChannelManageAction(
                 channel: chat.focusChannel!,
                 realm: realm,
-                onUpdate: () => chat.fetchChannel(chat.focusChannel!.alias, realm),
+                onUpdate: () => chat.fetchChannel(auth, chat.focusChannel!.alias, realm),
               ),
             ]
           : [],
@@ -96,11 +98,34 @@ class _ChatWidgetState extends State<ChatWidget> {
         final nextPageKey = pageKey + items.length;
         _pagingController.appendPage(items, nextPageKey);
       }
+    } else if (res.statusCode == 403) {
+      _pagingController.appendLastPage([]);
     } else {
       _pagingController.error = utf8.decode(res.bodyBytes);
     }
   }
 
+  Future<void> joinChannel() async {
+    final auth = context.read<AuthProvider>();
+    if (!await auth.isAuthorized()) return;
+
+    var uri = getRequestUri(
+      'messaging',
+      '/api/channels/${widget.realm}/${widget.alias}/members/me',
+    );
+
+    var res = await auth.client!.post(uri);
+    if (res.statusCode == 200) {
+      setState(() {});
+      _pagingController.refresh();
+    } else {
+      var message = utf8.decode(res.bodyBytes);
+      context.showErrorDialog(message).then((_) {
+        SolianRouter.router.pop();
+      });
+    }
+  }
+
   bool getMessageMergeable(Message? a, Message? b) {
     if (a?.replyTo != null) return false;
     if (a == null || b == null) return false;
@@ -145,15 +170,55 @@ class _ChatWidgetState extends State<ChatWidget> {
     );
   }
 
+  void showUnavailableDialog() {
+    final content = widget.realm == 'global'
+        ? AppLocalizations.of(context)!.chatChannelUnavailableCaption
+        : AppLocalizations.of(context)!.chatChannelUnavailableCaptionWithRealm;
+
+    showDialog(
+      context: context,
+      barrierDismissible: false,
+      builder: (context) => AlertDialog(
+        title: Text(AppLocalizations.of(context)!.chatChannelUnavailable),
+        content: Text(content),
+        actions: <Widget>[
+          TextButton(
+            child: Text(AppLocalizations.of(context)!.cancel),
+            onPressed: () {
+              Navigator.of(context).pop();
+              SolianRouter.router.pop();
+            },
+          ),
+          ...(widget.realm != 'global'
+              ? [
+                  TextButton(
+                    child: Text(AppLocalizations.of(context)!.join),
+                    onPressed: () {
+                      Navigator.of(context).pop();
+                      joinChannel();
+                    },
+                  ),
+                ]
+              : [])
+        ],
+      ),
+    );
+  }
+
   @override
   void initState() {
     _pagingController.addPageRequestListener((pageKey) => fetchMessages(pageKey, context));
 
     super.initState();
 
-    Future.delayed(Duration.zero, () {
+    Future.delayed(Duration.zero, () async {
+      final auth = context.read<AuthProvider>();
       _chat.fetchOngoingCall(widget.alias, widget.realm);
-      _chat.fetchChannel(widget.alias, widget.realm);
+      _chat.fetchChannel(auth, widget.alias, widget.realm).then((result) {
+        if (result.isAvailable == false) {
+          showUnavailableDialog();
+        }
+      });
     });
   }
 
diff --git a/lib/widgets/posts/post_deletion.dart b/lib/widgets/posts/post_deletion.dart
index b24f22f..8012e0e 100644
--- a/lib/widgets/posts/post_deletion.dart
+++ b/lib/widgets/posts/post_deletion.dart
@@ -29,8 +29,7 @@ class _ItemDeletionDialogState extends State<ItemDeletionDialog> {
     final auth = context.read<AuthProvider>();
     if (!await auth.isAuthorized()) return;
 
-    final uri =
-        getRequestUri('interactive', '/api/p/moments/${widget.item.id}');
+    final uri = getRequestUri('interactive', '/api/p/${widget.item.modelType}s/${widget.item.id}');
 
     setState(() => _isSubmitting = true);
     final res = await auth.client!.delete(uri);