Enable password self-registration and keep SSO off (#81)

## Summary
- Closes #80.
- Password self-registration is on by default (`ENABLE_ACCOUNT_REGISTRATION`). `/user/create/` issues tokens and `needs_checkout`, and the web sign-up page already redirects into Stripe Checkout.
- Browser SSO stays off (`ENABLE_SSO`, default false). Live Google and Microsoft client ids stay available for Drive linking, but public settings no longer advertise them, and login/signup OAuth start and callback are rejected.

Stripe path checked before this change: Checkout builds a subscription session (Founders at $10/month, or `STRIPE_PRICE_ID`), stores a draft invoice, and signed `checkout.session.completed` / `invoice.paid` webhooks grant the plan. Checkout, webhook, portal, registration, and OAuth tests passed.

## Deploy note
If `chat_backend_prod.env` or `chat_backend_beta.env` on the control node still sets `ENABLE_ACCOUNT_REGISTRATION=false`, that line overrides this default. Set it to `true` or remove it, and leave `ENABLE_SSO` unset or `false`.

## Test plan
- [ ] `GET /api/public/settings/` returns `enable_account_registration: true` and `oauth.google` / `oauth.microsoft` false.
- [ ] Sign-up form creates an account and redirects to Stripe Checkout. No Google or Microsoft button.
- [ ] Checkout success grants the Founders plan after the webhook.
- [ ] `/api/auth/oauth/google/start/?intent=signup` returns 403. Drive connect still starts.
- [ ] Setting `ENABLE_ACCOUNT_REGISTRATION=false` closes `/user/create/` again.

Reviewed-on: #81

llm_be/chat_backend/oauth.py

@@ -459,8 +459,8 @@ def resolve_user_from_profile(
         upsert_identity(email_user, profile)
         return email_user, False
 
-    # New account path
-    allow_create = settings.ENABLE_ACCOUNT_REGISTRATION
+    # New account path. Password registration does not enable SSO sign-up.
+    allow_create = settings.ENABLE_ACCOUNT_REGISTRATION and settings.ENABLE_SSO
     if intent == "signup" and not allow_create:
         raise OAuthError("registration_disabled", "Account registration is disabled.")
     if intent == "login" and not allow_create:

llm_be/chat_backend/tests/test_oauth.py

@@ -24,6 +24,7 @@ OAUTH_SETTINGS = {
     "FRONTEND_BASE_URL": "http://frontend.test",
     "OAUTH_CALLBACK_BASE_URL": "http://backend.test",
     "ENABLE_ACCOUNT_REGISTRATION": True,
+    "ENABLE_SSO": True,
 }
 
 
@@ -53,6 +54,14 @@ class PublicSettingsOAuthTestCase(APITestCase):
         self.assertTrue(response.data["oauth"]["google"])
         self.assertTrue(response.data["oauth"]["microsoft"])
 
+    @override_settings(ENABLE_SSO=False)
+    def test_hides_oauth_when_sso_disabled(self):
+        response = self.client.get(reverse("public_settings"))
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertTrue(response.data["enable_account_registration"])
+        self.assertFalse(response.data["oauth"]["google"])
+        self.assertFalse(response.data["oauth"]["microsoft"])
+
     @override_settings(GOOGLE_OAUTH_CLIENT_ID="", GOOGLE_OAUTH_CLIENT_SECRET="")
     def test_hides_unconfigured_provider(self):
         response = self.client.get(reverse("public_settings"))
@@ -83,6 +92,15 @@ class OAuthStartTestCase(APITestCase):
         )
         self.assertEqual(response.status_code, status.HTTP_404_NOT_FOUND)
 
+    @override_settings(ENABLE_SSO=False)
+    def test_login_and_signup_blocked_when_sso_disabled(self):
+        for intent in ("login", "signup"):
+            response = self.client.get(
+                reverse("oauth_start", kwargs={"provider": "google"}),
+                {"intent": intent},
+            )
+            self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+
     @override_settings(ENABLE_ACCOUNT_REGISTRATION=False)
     def test_signup_intent_blocked_when_registration_disabled(self):
         response = self.client.get(
@@ -180,6 +198,17 @@ class OAuthCallbackTestCase(APITestCase):
         params = parse_qs(urlparse(response["Location"]).query)
         self.assertEqual(params["error"], ["email_missing"])
 
+    @patch("chat_backend.views_oauth.exchange_code_for_profile")
+    @override_settings(ENABLE_SSO=False)
+    def test_callback_signup_rejected_when_sso_disabled(self, mock_exchange):
+        mock_exchange.return_value = _google_profile()
+
+        response = self._callback(intent="signup")
+        params = parse_qs(urlparse(response["Location"]).query)
+        self.assertEqual(params["error"], ["sso_disabled"])
+        self.assertEqual(CustomUser.objects.count(), 0)
+        mock_exchange.assert_not_called()
+
     @patch("chat_backend.views_oauth.exchange_code_for_profile")
     @override_settings(ENABLE_ACCOUNT_REGISTRATION=False)
     def test_callback_login_without_account_when_registration_off(self, mock_exchange):
@@ -256,6 +285,15 @@ class OAuthStartDriveLinkTestCase(APITestCase):
         )
         self.assertEqual(response.status_code, status.HTTP_401_UNAUTHORIZED)
 
+    @override_settings(ENABLE_SSO=False)
+    def test_link_drive_still_starts_when_sso_disabled(self):
+        self.client.force_authenticate(user=self.user)
+        response = self.client.get(
+            reverse("oauth_start", kwargs={"provider": "google"}),
+            {"intent": "link_drive"},
+        )
+        self.assertEqual(response.status_code, status.HTTP_302_FOUND)
+
     def test_link_drive_authenticated_redirects_with_drive_scope_and_state(self):
         self.client.force_authenticate(user=self.user)
         response = self.client.get(

llm_be/chat_backend/tests/test_views_users.py

@@ -115,15 +115,33 @@ class PublicSettingsTestCase(APITestCase):
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertEqual(response.data["enable_account_registration"], False)
 
+    def test_registration_on_and_sso_hidden_by_default(self):
+        response = self.client.get(reverse("public_settings"))
+
+        self.assertEqual(response.status_code, status.HTTP_200_OK)
+        self.assertEqual(response.data["enable_account_registration"], True)
+        self.assertEqual(response.data["oauth"], {"google": False, "microsoft": False})
+
 
 class UserCreateTestCase(APITestCase):
-    def test_registration_disabled_by_default(self):
+    def test_registration_enabled_by_default(self):
         response = self.client.post(
             reverse("create_user"),
             {"email": "new@example.com", "password": "securepass1"},
             format="json",
         )
 
+        self.assertEqual(response.status_code, status.HTTP_201_CREATED)
+        self.assertTrue(CustomUser.objects.filter(email="new@example.com").exists())
+
+    def test_registration_disabled_when_setting_off(self):
+        with self.settings(ENABLE_ACCOUNT_REGISTRATION=False):
+            response = self.client.post(
+                reverse("create_user"),
+                {"email": "new@example.com", "password": "securepass1"},
+                format="json",
+            )
+
         self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
         self.assertEqual(CustomUser.objects.count(), 0)
 

llm_be/chat_backend/views.py

@@ -178,7 +178,7 @@ class PublicWaitlistView(APIView):
 
 
 class CustomUserCreate(APIView):
-    """Self-serve registration. Gated by ENABLE_ACCOUNT_REGISTRATION (default off)."""
+    """Password self-serve registration. Gated by ENABLE_ACCOUNT_REGISTRATION."""
 
     permission_classes = (permissions.AllowAny,)
     authentication_classes = ()

llm_be/chat_backend/views_oauth.py

@@ -102,6 +102,11 @@ class OAuthStartView(APIView):
                 },
                 status=status.HTTP_400_BAD_REQUEST,
             )
+        if intent in {"login", "signup"} and not settings.ENABLE_SSO:
+            return Response(
+                {"detail": "Single sign-on is not enabled."},
+                status=status.HTTP_403_FORBIDDEN,
+            )
         if intent == "signup" and not settings.ENABLE_ACCOUNT_REGISTRATION:
             return Response(
                 {"detail": "Account registration is disabled."},
@@ -184,6 +189,8 @@ class OAuthCallbackView(APIView):
             return self._handle_drive_link_callback(
                 request, provider=provider, code=code, state_data=state_data
             )
+        if not settings.ENABLE_SSO:
+            return _redirect_error("sso_disabled", "Single sign-on is not enabled.")
 
         try:
             redirect_uri = _callback_redirect_uri(request, provider)
@@ -261,5 +268,7 @@ class OAuthCallbackView(APIView):
 
 
 def oauth_public_flags() -> dict:
-    """Feature flags for /public/settings/."""
+    """Feature flags for /public/settings/. SSO buttons stay hidden until ENABLE_SSO."""
+    if not settings.ENABLE_SSO:
+        return {"google": False, "microsoft": False}
     return configured_providers()

llm_be/llm_be/settings.py

@@ -381,9 +381,12 @@ AGENT_FETCH_URL_MAX_BYTES = int(
     env("AGENT_FETCH_URL_MAX_BYTES", str(2 * 1024 * 1024)) or str(2 * 1024 * 1024)
 )
 
-# Self-serve account registration (sign-up page). Default off — enable via
-# control-node secret (chat_backend_<env>.env) when ready for public sign-up.
-ENABLE_ACCOUNT_REGISTRATION = env_bool("ENABLE_ACCOUNT_REGISTRATION", False)
+# Password self-serve sign-up. On by default (#80). Set false in the
+# control-node secret (chat_backend_<env>.env) to close public registration.
+ENABLE_ACCOUNT_REGISTRATION = env_bool("ENABLE_ACCOUNT_REGISTRATION", True)
+# Browser SSO (Google / Microsoft sign-in and sign-up). Off until explicitly
+# enabled. OAuth client ids may still be set for Drive linking (#47).
+ENABLE_SSO = env_bool("ENABLE_SSO", False)
 
 # ---------------------------------------------------------------------------
 # OAuth SSO (Google / Microsoft) — #24