diff --git a/.vscode/settings.json b/.vscode/settings.json
index 25ea52b..8708bf5 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -3,6 +3,7 @@
         "Appbar",
         "Displayname",
         "Homeserver",
+        "localpart",
         "prefs",
         "vodozemac"
     ]
diff --git a/lib/controllers/author_controller.dart b/lib/controllers/author_controller.dart
index 8b709d3..70b7343 100644
--- a/lib/controllers/author_controller.dart
+++ b/lib/controllers/author_controller.dart
@@ -1,10 +1,10 @@
 import "dart:async";
-import "package:collection/collection.dart";
 import "package:fast_immutable_collections/fast_immutable_collections.dart";
 import "package:flutter_chat_core/flutter_chat_core.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:nexus/controllers/client_state_controller.dart";
-import "package:nexus/controllers/members_controller.dart";
+import "package:nexus/controllers/user_controller.dart";
+import "package:nexus/helpers/extensions/get_localpart.dart";
 import "package:nexus/models/membership.dart";
 import "package:nexus/models/membership_status.dart";
 
@@ -15,11 +15,7 @@ class AuthorController extends AsyncNotifier<Membership> {
   @override
   Future<Membership> build() async {
     final member = await ref.watch(
-      MembersController.provider.selectAsync(
-        (value) => value.firstWhereOrNull(
-          (membership) => membership.userId == message.authorId,
-        ),
-      ),
+      UserController.provider(message.authorId).future,
     );
 
     final pmp = message.metadata?["pmp"] == null
@@ -39,9 +35,7 @@ class AuthorController extends AsyncNotifier<Membership> {
       status: member?.status ?? MembershipStatus.leave,
       avatarUrl: pmp?.avatarUrl ?? member?.avatarUrl,
       displayName:
-          pmp?.displayName ??
-          member?.displayName ??
-          message.authorId.substring(1).split(":").first,
+          pmp?.displayName ?? member?.displayName ?? message.authorId.localpart,
       userId: message.authorId,
     );
   }
diff --git a/lib/controllers/user_controller.dart b/lib/controllers/user_controller.dart
new file mode 100644
index 0000000..e7ca973
--- /dev/null
+++ b/lib/controllers/user_controller.dart
@@ -0,0 +1,40 @@
+import "dart:async";
+import "package:collection/collection.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/members_controller.dart";
+import "package:nexus/controllers/profile_controller.dart";
+import "package:nexus/helpers/extensions/get_localpart.dart";
+import "package:nexus/models/membership.dart";
+import "package:nexus/models/membership_status.dart";
+
+class UserController extends AsyncNotifier<Membership?> {
+  final String userId;
+  UserController(this.userId);
+
+  @override
+  Future<Membership?> build() async {
+    final member = await ref.watch(
+      MembersController.provider.selectAsync(
+        (value) =>
+            value.firstWhereOrNull((membership) => membership.userId == userId),
+      ),
+    );
+
+    if (member != null) return member;
+
+    final profile = await ref.watch(ProfileController.provider(userId).future);
+    return Membership(
+      status: MembershipStatus.leave,
+      avatarUrl: profile.avatarUrl == null
+          ? null
+          : Uri.tryParse(profile.avatarUrl!),
+      displayName: profile.displayName ?? userId.localpart,
+      userId: userId,
+    );
+  }
+
+  static final provider =
+      AsyncNotifierProvider.family<UserController, Membership?, String>(
+        UserController.new,
+      );
+}
diff --git a/lib/helpers/extensions/get_localpart.dart b/lib/helpers/extensions/get_localpart.dart
new file mode 100644
index 0000000..445351f
--- /dev/null
+++ b/lib/helpers/extensions/get_localpart.dart
@@ -0,0 +1,3 @@
+extension GetLocalpart on String {
+  String get localpart => substring(1).split(":").first;
+}
diff --git a/lib/widgets/chat_page/html/mention_chip.dart b/lib/widgets/chat_page/html/mention_chip.dart
index c2b832d..6e9b741 100644
--- a/lib/widgets/chat_page/html/mention_chip.dart
+++ b/lib/widgets/chat_page/html/mention_chip.dart
@@ -1,25 +1,44 @@
 import "package:flutter/material.dart";
+import "package:flutter_riverpod/flutter_riverpod.dart";
+import "package:nexus/controllers/user_controller.dart";
 import "package:nexus/helpers/extensions/link_to_mention.dart";
+import "package:nexus/helpers/extensions/show_user_popover.dart";
 
-class MentionChip extends StatelessWidget {
+class MentionChip extends ConsumerWidget {
   final String label;
   const MentionChip(this.label, {super.key});
 
   @override
-  Widget build(BuildContext context) => ActionChip(
-    label: Text(
-      label.mention ?? label,
-      style: TextStyle(
-        fontWeight: FontWeight.bold,
-        color: Theme.of(context).colorScheme.onPrimary,
+  Widget build(BuildContext context, WidgetRef ref) {
+    final mention = label.mention;
+    final membership =
+        mention?.startsWith("@") == true || label.startsWith("@") == true
+        ? ref
+              .watch(UserController.provider(mention ?? label))
+              .whenOrNull(data: (data) => data)
+        : null;
+
+    return InkWell(
+      onTapUp: (details) {
+        if (membership != null) {
+          context.showUserPopover(
+            membership,
+            globalPosition: details.globalPosition,
+          );
+        }
+      },
+      child: Chip(
+        label: Text(
+          (membership == null ? null : "@${membership.displayName}") ??
+              mention ??
+              label,
+          style: TextStyle(
+            fontWeight: FontWeight.bold,
+            color: Theme.of(context).colorScheme.onPrimary,
+          ),
+        ),
+        backgroundColor: Theme.of(context).colorScheme.primary,
       ),
-    ),
-    backgroundColor: Theme.of(context).colorScheme.primary,
-    onPressed: () => showDialog(
-      context: context,
-      builder: (_) => Dialog(
-        child: Text("TODO: Open room or join room dialog, or user popover"),
-      ),
-    ),
-  );
+    );
+  }
 }