diff --git a/internal/cmd/calendar_create_update_test.go b/internal/cmd/calendar_create_update_test.go
index 455a0edf5..c9f467211 100644
--- a/internal/cmd/calendar_create_update_test.go
+++ b/internal/cmd/calendar_create_update_test.go
@@ -634,3 +634,103 @@ func TestCalendarUpdateCmd_ScopeFuture(t *testing.T) {
 		t.Fatalf("expected recurrence truncation")
 	}
 }
+
+func TestCalendarUpdateCmd_SendUpdates(t *testing.T) {
+	origNew := newCalendarService
+	t.Cleanup(func() { newCalendarService = origNew })
+
+	var gotSendUpdates string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		path := strings.TrimPrefix(r.URL.Path, "/calendar/v3")
+		if r.Method == http.MethodPatch && path == "/calendars/cal/events/ev" {
+			gotSendUpdates = r.URL.Query().Get("sendUpdates")
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"id":      "ev",
+				"summary": "Updated",
+			})
+			return
+		}
+		http.NotFound(w, r)
+	}))
+	defer srv.Close()
+
+	svc, err := calendar.NewService(context.Background(),
+		option.WithoutAuthentication(),
+		option.WithHTTPClient(srv.Client()),
+		option.WithEndpoint(srv.URL+"/"),
+	)
+	if err != nil {
+		t.Fatalf("NewService: %v", err)
+	}
+	newCalendarService = func(context.Context, string) (*calendar.Service, error) { return svc, nil }
+
+	u, err := ui.New(ui.Options{Stdout: os.Stdout, Stderr: os.Stderr, Color: "never"})
+	if err != nil {
+		t.Fatalf("ui.New: %v", err)
+	}
+	ctx := outfmt.WithMode(ui.WithUI(context.Background(), u), outfmt.Mode{JSON: true})
+
+	cmd := &CalendarUpdateCmd{}
+	if err := runKong(t, cmd, []string{
+		"cal",
+		"ev",
+		"--summary", "Updated",
+		"--send-updates", "all",
+	}, ctx, &RootFlags{Account: "a@b.com"}); err != nil {
+		t.Fatalf("runKong: %v", err)
+	}
+	if gotSendUpdates != "all" {
+		t.Fatalf("expected sendUpdates=all, got %q", gotSendUpdates)
+	}
+}
+
+func TestCalendarUpdateCmd_SendUpdatesExternalOnly(t *testing.T) {
+	origNew := newCalendarService
+	t.Cleanup(func() { newCalendarService = origNew })
+
+	var gotSendUpdates string
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		path := strings.TrimPrefix(r.URL.Path, "/calendar/v3")
+		if r.Method == http.MethodPatch && path == "/calendars/cal/events/ev" {
+			gotSendUpdates = r.URL.Query().Get("sendUpdates")
+			w.Header().Set("Content-Type", "application/json")
+			_ = json.NewEncoder(w).Encode(map[string]any{
+				"id":      "ev",
+				"summary": "Updated",
+			})
+			return
+		}
+		http.NotFound(w, r)
+	}))
+	defer srv.Close()
+
+	svc, err := calendar.NewService(context.Background(),
+		option.WithoutAuthentication(),
+		option.WithHTTPClient(srv.Client()),
+		option.WithEndpoint(srv.URL+"/"),
+	)
+	if err != nil {
+		t.Fatalf("NewService: %v", err)
+	}
+	newCalendarService = func(context.Context, string) (*calendar.Service, error) { return svc, nil }
+
+	u, err := ui.New(ui.Options{Stdout: os.Stdout, Stderr: os.Stderr, Color: "never"})
+	if err != nil {
+		t.Fatalf("ui.New: %v", err)
+	}
+	ctx := outfmt.WithMode(ui.WithUI(context.Background(), u), outfmt.Mode{JSON: true})
+
+	cmd := &CalendarUpdateCmd{}
+	if err := runKong(t, cmd, []string{
+		"cal",
+		"ev",
+		"--summary", "Updated",
+		"--send-updates", "externalOnly",
+	}, ctx, &RootFlags{Account: "a@b.com"}); err != nil {
+		t.Fatalf("runKong: %v", err)
+	}
+	if gotSendUpdates != "externalOnly" {
+		t.Fatalf("expected sendUpdates=externalOnly, got %q", gotSendUpdates)
+	}
+}
diff --git a/internal/cmd/calendar_edit.go b/internal/cmd/calendar_edit.go
index b51991335..5c84aa720 100644
--- a/internal/cmd/calendar_edit.go
+++ b/internal/cmd/calendar_edit.go
@@ -325,6 +325,7 @@ type CalendarUpdateCmd struct {
 	ColorId               string   `name:"event-color" help:"Event color ID (1-11, or empty to clear)"`
 	Visibility            string   `name:"visibility" help:"Event visibility: default, public, private, confidential"`
 	Transparency          string   `name:"transparency" help:"Show as busy (opaque) or free (transparent). Aliases: busy, free"`
+	SendUpdates           string   `name:"send-updates" help:"Notification mode: all, externalOnly, none (default: all)"`
 	GuestsCanInviteOthers *bool    `name:"guests-can-invite" help:"Allow guests to invite others"`
 	GuestsCanModify       *bool    `name:"guests-can-modify" help:"Allow guests to modify event"`
 	GuestsCanSeeOthers    *bool    `name:"guests-can-see-others" help:"Allow guests to see other guests"`