diff --git a/gateway/platforms/discord.py b/gateway/platforms/discord.py
index f79678bc61a..558903ba297 100644
--- a/gateway/platforms/discord.py
+++ b/gateway/platforms/discord.py
@@ -111,6 +111,7 @@ def check_discord_requirements() -> bool:
     Intents = _Intents
     commands = _commands
     DISCORD_AVAILABLE = True
+    _define_discord_view_classes()
     return True
 
 
@@ -4949,7 +4950,17 @@ def _component_check_auth(
     return False
 
 
-if DISCORD_AVAILABLE:
+def _define_discord_view_classes() -> None:
+    """Register Discord UI view classes as module globals.
+
+    Called at module load (when discord.py is pre-installed) and also from
+    check_discord_requirements() after a lazy install, so view classes are
+    always defined whenever DISCORD_AVAILABLE is True.  Without this,
+    ExecApprovalView and siblings are only defined at import time; a later
+    lazy install sets DISCORD_AVAILABLE=True but leaves the classes
+    undefined, causing NameError on the first button interaction.
+    """
+    global ExecApprovalView, SlashConfirmView, UpdatePromptView, ModelPickerView, ClarifyChoiceView
 
     class ExecApprovalView(discord.ui.View):
         """
@@ -5649,3 +5660,7 @@ if DISCORD_AVAILABLE:
             self.resolved = True
             for child in self.children:
                 child.disabled = True
+
+
+if DISCORD_AVAILABLE:
+    _define_discord_view_classes()
diff --git a/tests/gateway/test_discord_lazy_install_views.py b/tests/gateway/test_discord_lazy_install_views.py
new file mode 100644
index 00000000000..62f2b974e02
--- /dev/null
+++ b/tests/gateway/test_discord_lazy_install_views.py
@@ -0,0 +1,81 @@
+"""Regression: Discord UI view classes must be defined after lazy-install.
+
+When discord.py is NOT installed at module load time, the
+``if DISCORD_AVAILABLE:`` guard at the bottom of gateway/platforms/discord.py
+evaluates to False and is skipped — leaving ExecApprovalView and its four
+siblings undefined in the module globals.
+
+check_discord_requirements() must call _define_discord_view_classes() after
+a successful lazy install so that all view classes are available the moment
+DISCORD_AVAILABLE flips to True.  Without this, the first button interaction
+(exec approval, slash confirm, etc.) raises NameError even though
+DISCORD_AVAILABLE=True.
+
+Fixes: lazy-install path NameError for ExecApprovalView, SlashConfirmView,
+UpdatePromptView, ModelPickerView, ClarifyChoiceView.
+"""
+import importlib
+import sys
+from unittest.mock import patch
+
+import pytest
+
+_VIEW_NAMES = [
+    "ExecApprovalView",
+    "SlashConfirmView",
+    "UpdatePromptView",
+    "ModelPickerView",
+    "ClarifyChoiceView",
+]
+
+
+class TestDefineDiscordViewClasses:
+    """_define_discord_view_classes() registers all UI view classes in module globals."""
+
+    def test_registers_all_five_view_classes(self, monkeypatch):
+        """Calling _define_discord_view_classes() must (re)define all 5 view classes."""
+        dp = importlib.import_module("gateway.platforms.discord")
+
+        # Remove the classes to simulate the state where the module was loaded
+        # with DISCORD_AVAILABLE=False (the lazy-install scenario).
+        for name in _VIEW_NAMES:
+            monkeypatch.delattr(dp, name)
+
+        # Pre-condition: classes are gone
+        for name in _VIEW_NAMES:
+            assert not hasattr(dp, name), f"{name} should be absent before the call"
+
+        dp._define_discord_view_classes()
+
+        for name in _VIEW_NAMES:
+            assert hasattr(dp, name), f"{name} must be defined after _define_discord_view_classes()"
+            assert isinstance(getattr(dp, name), type), f"{name} must be a class"
+
+    def test_check_discord_requirements_calls_define_on_lazy_install(self, monkeypatch):
+        """check_discord_requirements() must call _define_discord_view_classes() on
+        a successful lazy install so view classes exist when DISCORD_AVAILABLE=True."""
+        dp = importlib.import_module("gateway.platforms.discord")
+
+        # Simulate discord not yet available at module load.
+        monkeypatch.setattr(dp, "DISCORD_AVAILABLE", False)
+
+        define_called = [False]
+        orig_define = dp._define_discord_view_classes
+
+        def _spy_define():
+            define_called[0] = True
+            orig_define()
+
+        monkeypatch.setattr(dp, "_define_discord_view_classes", _spy_define)
+
+        # Patch lazy_deps.ensure to be a no-op (pretend install succeeds).
+        # The discord imports inside check_discord_requirements() succeed because
+        # _ensure_discord_mock() in conftest.py already registered the mock.
+        with patch("tools.lazy_deps.ensure"):
+            result = dp.check_discord_requirements()
+
+        assert result is True, "check_discord_requirements() should return True after lazy install"
+        assert define_called[0], (
+            "check_discord_requirements() must call _define_discord_view_classes() "
+            "after a successful lazy install so view classes are not undefined"
+        )