diff --git a/.cursor/rules/i18n.md b/.cursor/rules/i18n.md
new file mode 100644
index 000000000..336c9d995
--- /dev/null
+++ b/.cursor/rules/i18n.md
@@ -0,0 +1,7 @@
+- We use the fluent system+code generation for translation.
+- New strings should be added to rslib/core/. Ask for the appropriate file if you're not sure.
+- Assuming a string addons-you-have-count has been added to addons.ftl, that string is accessible in our different languages as follows:
+  - Python: from aqt.utils import tr; msg = tr.addons_you_have_count(count=3)
+  - TypeScript: import * as tr from "@generated/ftl"; tr.addonsYouHaveCount({count: 3})
+  - Rust: collection.tr.addons_you_have_count(3)
+- In Qt .ui files, strings that are marked as translatable will automatically use the registered ftl strings. So a QLabel with a title 'addons_you_have_count' that is marked as translatable will automatically use the translation defined in our addons.ftl file.
diff --git a/.cursor/rules/testing.md b/.cursor/rules/testing.md
new file mode 100644
index 000000000..47a530219
--- /dev/null
+++ b/.cursor/rules/testing.md
@@ -0,0 +1,2 @@
+- To build and check the project, use ./check(.bat)
+- This will format files, then run lints and unit tests.
diff --git a/ftl/core/preferences.ftl b/ftl/core/preferences.ftl
index 69a9300a0..a0983dd6c 100644
--- a/ftl/core/preferences.ftl
+++ b/ftl/core/preferences.ftl
@@ -83,6 +83,13 @@ preferences-ankiweb-intro = AnkiWeb is a free service that lets you keep your fl
 preferences-ankihub-intro = AnkiHub provides collaborative deck editing and additional study tools. A paid subscription is required to access certain features.
 preferences-third-party-description = Third-party services are unaffiliated with and not endorsed by Anki. Use of these services may require payment.
 
+## URL scheme related
+preferences-url-schemes = URL Schemes
+preferences-url-scheme-prompt = Allowed { preferences-url-schemes } (space-separated):
+preferences-url-scheme-warning = Blocked attempt to open `{ $link }`, which may be a security issue.
+
+    If you trust the deck author and wish to proceed, you can add `{ $scheme }` to your allowed { preferences-url-schemes }.
+
 ## NO NEED TO TRANSLATE. This text is no longer used by Anki, and will be removed in the future.
 
 preferences-basic = Basic
diff --git a/qt/aqt/forms/preferences.ui b/qt/aqt/forms/preferences.ui
index 34de8c80e..807d4093c 100644
--- a/qt/aqt/forms/preferences.ui
+++ b/qt/aqt/forms/preferences.ui
@@ -17,7 +17,7 @@
    <item>
     <widget class="QTabWidget" name="tabWidget">
      <property name="focusPolicy">
-      <enum>Qt::StrongFocus</enum>
+      <enum>Qt::FocusPolicy::StrongFocus</enum>
      </property>
      <property name="currentIndex">
       <number>0</number>
@@ -78,7 +78,7 @@
              </sizepolicy>
             </property>
             <property name="sizeAdjustPolicy">
-             <enum>QComboBox::AdjustToMinimumContentsLengthWithIcon</enum>
+             <enum>QComboBox::SizeAdjustPolicy::AdjustToMinimumContentsLengthWithIcon</enum>
             </property>
            </widget>
           </item>
@@ -260,7 +260,7 @@
        <item>
         <spacer name="verticalSpacer_9">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -451,6 +451,13 @@
               </property>
              </widget>
             </item>
+            <item>
+             <widget class="QPushButton" name="url_schemes">
+              <property name="text">
+               <string>preferences_url_schemes</string>
+              </property>
+             </widget>
+            </item>
            </layout>
           </widget>
          </item>
@@ -466,7 +473,7 @@
        <item>
         <spacer name="verticalSpacer_12">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -518,10 +525,10 @@
           <item>
            <spacer name="verticalSpacer_7">
             <property name="orientation">
-             <enum>Qt::Vertical</enum>
+             <enum>Qt::Orientation::Vertical</enum>
             </property>
             <property name="sizeType">
-             <enum>QSizePolicy::Fixed</enum>
+             <enum>QSizePolicy::Policy::Fixed</enum>
             </property>
             <property name="sizeHint" stdset="0">
              <size>
@@ -614,10 +621,10 @@
        <item>
         <spacer name="verticalSpacer_3">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeType">
-          <enum>QSizePolicy::Expanding</enum>
+          <enum>QSizePolicy::Policy::Expanding</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -739,7 +746,7 @@
             <item>
              <spacer name="horizontalSpacer">
               <property name="orientation">
-               <enum>Qt::Horizontal</enum>
+               <enum>Qt::Orientation::Horizontal</enum>
               </property>
               <property name="sizeHint" stdset="0">
                <size>
@@ -827,7 +834,7 @@
        <item>
         <spacer name="verticalSpacer_2">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -840,7 +847,7 @@
        <item>
         <spacer name="verticalSpacer_2">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -918,10 +925,10 @@
           <item>
            <spacer name="verticalSpacer_5">
             <property name="orientation">
-             <enum>Qt::Vertical</enum>
+             <enum>Qt::Orientation::Vertical</enum>
             </property>
             <property name="sizeType">
-             <enum>QSizePolicy::Fixed</enum>
+             <enum>QSizePolicy::Policy::Fixed</enum>
             </property>
             <property name="sizeHint" stdset="0">
              <size>
@@ -953,7 +960,7 @@
             <item row="1" column="3">
              <spacer name="horizontalSpacer_2">
               <property name="orientation">
-               <enum>Qt::Horizontal</enum>
+               <enum>Qt::Orientation::Horizontal</enum>
               </property>
               <property name="sizeHint" stdset="0">
                <size>
@@ -1020,7 +1027,7 @@
             <item row="1" column="1">
              <spacer name="horizontalSpacer_3">
               <property name="orientation">
-               <enum>Qt::Horizontal</enum>
+               <enum>Qt::Orientation::Horizontal</enum>
               </property>
               <property name="sizeHint" stdset="0">
                <size>
@@ -1035,10 +1042,10 @@
           <item>
            <spacer name="verticalSpacer_6">
             <property name="orientation">
-             <enum>Qt::Vertical</enum>
+             <enum>Qt::Orientation::Vertical</enum>
             </property>
             <property name="sizeType">
-             <enum>QSizePolicy::Fixed</enum>
+             <enum>QSizePolicy::Policy::Fixed</enum>
             </property>
             <property name="sizeHint" stdset="0">
              <size>
@@ -1080,7 +1087,7 @@
        <item>
         <spacer name="verticalSpacer_4">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -1128,10 +1135,10 @@
        <item>
         <spacer name="verticalSpacer">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeType">
-          <enum>QSizePolicy::Maximum</enum>
+          <enum>QSizePolicy::Policy::Maximum</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -1207,7 +1214,7 @@
        <item>
         <spacer name="verticalspacer_13">
          <property name="orientation">
-          <enum>Qt::Vertical</enum>
+          <enum>Qt::Orientation::Vertical</enum>
          </property>
          <property name="sizeHint" stdset="0">
           <size>
@@ -1227,17 +1234,17 @@
       <string>preferences_some_settings_will_take_effect_after</string>
      </property>
      <property name="alignment">
-      <set>Qt::AlignCenter</set>
+      <set>Qt::AlignmentFlag::AlignCenter</set>
      </property>
     </widget>
    </item>
    <item>
     <widget class="QDialogButtonBox" name="buttonBox">
      <property name="orientation">
-      <enum>Qt::Horizontal</enum>
+      <enum>Qt::Orientation::Horizontal</enum>
      </property>
      <property name="standardButtons">
-      <set>QDialogButtonBox::Close|QDialogButtonBox::Help</set>
+      <set>QDialogButtonBox::StandardButton::Close|QDialogButtonBox::StandardButton::Help</set>
      </property>
     </widget>
    </item>
@@ -1266,6 +1273,7 @@
   <tabstop>showEstimates</tabstop>
   <tabstop>spacebar_rates_card</tabstop>
   <tabstop>render_latex</tabstop>
+  <tabstop>url_schemes</tabstop>
   <tabstop>pastePNG</tabstop>
   <tabstop>paste_strips_formatting</tabstop>
   <tabstop>useCurrent</tabstop>
diff --git a/qt/aqt/preferences.py b/qt/aqt/preferences.py
index 37483427a..bd87ef830 100644
--- a/qt/aqt/preferences.py
+++ b/qt/aqt/preferences.py
@@ -20,9 +20,11 @@ from aqt.profiles import VideoDriver
 from aqt.qt import *
 from aqt.sync import sync_login
 from aqt.theme import Theme
+from aqt.url_schemes import show_url_schemes_dialog
 from aqt.utils import (
     HelpPage,
     add_close_shortcut,
+    add_ellipsis_to_action_label,
     askUser,
     disable_help_button,
     is_win,
@@ -152,6 +154,9 @@ class Preferences(QDialog):
         form.monthly_backups.setValue(self.prefs.backups.monthly)
         form.minutes_between_backups.setValue(self.prefs.backups.minimum_interval_mins)
 
+        add_ellipsis_to_action_label(self.form.url_schemes)
+        qconnect(self.form.url_schemes.clicked, show_url_schemes_dialog)
+
     def update_collection(self, on_done: Callable[[], None]) -> None:
         form = self.form
 
diff --git a/qt/aqt/profiles.py b/qt/aqt/profiles.py
index d92d7f59f..0fd85ca8f 100644
--- a/qt/aqt/profiles.py
+++ b/qt/aqt/profiles.py
@@ -744,3 +744,9 @@ create table if not exists profiles
 
     def ankihub_username(self) -> str | None:
         return self.profile.get("thirdPartyAnkiHubUsername")
+
+    def allowed_url_schemes(self) -> list[str]:
+        return self.profile.get("allowedUrlSchemes", [])
+
+    def set_allowed_url_schemes(self, schemes: list[str]) -> None:
+        self.profile["allowedUrlSchemes"] = schemes
diff --git a/qt/aqt/url_schemes.py b/qt/aqt/url_schemes.py
new file mode 100644
index 000000000..f5ee1110d
--- /dev/null
+++ b/qt/aqt/url_schemes.py
@@ -0,0 +1,58 @@
+# Copyright: Ankitects Pty Ltd and contributors
+# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
+
+from __future__ import annotations
+
+from markdown import markdown
+
+from aqt.qt import Qt, QUrl
+from aqt.utils import ask_user_dialog, getText, openLink, tr
+
+
+def show_url_schemes_dialog() -> None:
+    from aqt import mw
+
+    default = " ".join(mw.pm.allowed_url_schemes())
+    schemes, ok = getText(
+        prompt=tr.preferences_url_scheme_prompt(),
+        title=tr.preferences_url_schemes(),
+        default=default,
+    )
+    if ok:
+        mw.pm.set_allowed_url_schemes(schemes.split(" "))
+        mw.pm.save()
+
+
+def is_supported_scheme(url: QUrl) -> bool:
+    from aqt import mw
+
+    scheme = url.scheme().lower()
+    allowed_schemes = mw.pm.allowed_url_schemes()
+
+    return scheme in allowed_schemes or scheme in ["http", "https"]
+
+
+def open_url_if_supported_scheme(url: QUrl) -> None:
+    from aqt import mw
+
+    if is_supported_scheme(url):
+        openLink(url)
+    else:
+
+        def on_button(idx: int) -> None:
+            if idx == 0:
+                show_url_schemes_dialog()
+
+        msg = markdown(
+            tr.preferences_url_scheme_warning(link=url.toString(), scheme=url.scheme())
+        )
+        ask_user_dialog(
+            msg,
+            buttons=[
+                tr.actions_with_ellipsis(action=tr.preferences_url_schemes()),
+                tr.actions_close(),
+            ],
+            parent=mw,
+            callback=on_button,
+            textFormat=Qt.TextFormat.RichText,
+        )
diff --git a/qt/aqt/utils.py b/qt/aqt/utils.py
index a11eb14b7..6ae8bace8 100644
--- a/qt/aqt/utils.py
+++ b/qt/aqt/utils.py
@@ -1188,7 +1188,7 @@ def disallow_full_screen() -> bool:
     )
 
 
-def add_ellipsis_to_action_label(*actions: QAction) -> None:
+def add_ellipsis_to_action_label(*actions: QAction | QPushButton) -> None:
     """Pass actions to add '...' to their labels, indicating that more input is
     required before they can be performed.
 
diff --git a/qt/aqt/webview.py b/qt/aqt/webview.py
index 4db506e49..966d3de5a 100644
--- a/qt/aqt/webview.py
+++ b/qt/aqt/webview.py
@@ -266,7 +266,9 @@ class AnkiWebPage(QWebEnginePage):
             print("onclick handler needs to return false")
             return False
         # load all other links in browser
-        openLink(url)
+        from aqt.url_schemes import open_url_if_supported_scheme
+
+        open_url_if_supported_scheme(url)
         return False
 
     def _onCmd(self, str: str) -> Any: