diff --git a/cmd/api/gen_warning_test.go b/cmd/api/gen_warning_test.go
new file mode 100644
index 00000000..52bd07b7
--- /dev/null
+++ b/cmd/api/gen_warning_test.go
@@ -0,0 +1,38 @@
+package api
+
+import (
+	"testing"
+
+	"github.com/go-admin-team/go-admin-core/v2/sdk/config"
+)
+
+// The warning fires exactly where the generator's writing endpoints are served
+// and nothing else refuses them.
+//
+// dev is the case the warning exists for: it is the shipped default, so it is
+// the mode a deployment that changed nothing is running in. demo serves the
+// routes too, but DemoEvn refuses all three by name, so warning there would
+// describe an exposure that is not there.
+func TestGeneratorWriteRoutesWarningFiresWhereTheExposureIs(t *testing.T) {
+	for _, tc := range []struct {
+		mode string
+		want bool
+		why  string
+	}{
+		{"dev", true, "shipped default, endpoints served and not refused"},
+		{"demo", false, "served, but DemoEvn refuses all three"},
+		{"test", false, "not served"},
+		{"prod", false, "not served"},
+		{"", false, "not served"},
+	} {
+		t.Run("mode="+tc.mode, func(t *testing.T) {
+			previous := config.ApplicationConfig.Mode
+			t.Cleanup(func() { config.ApplicationConfig.Mode = previous })
+			config.ApplicationConfig.Mode = tc.mode
+
+			if got := generatorWriteRoutesNeedWarning(); got != tc.want {
+				t.Errorf("mode %q: warning = %v, want %v (%s)", tc.mode, got, tc.want, tc.why)
+			}
+		})
+	}
+}
diff --git a/cmd/api/server.go b/cmd/api/server.go
index e084e49b..7d000d48 100644
--- a/cmd/api/server.go
+++ b/cmd/api/server.go
@@ -177,6 +177,7 @@ func run() error {
 		gin.SetMode(gin.ReleaseMode)
 	}
 	buildRouter()
+	reportGeneratorWriteRoutes()
 
 	srv := &http.Server{
 		Addr:         fmt.Sprintf("%s:%d", config.ApplicationConfig.Host, config.ApplicationConfig.Port),
@@ -356,6 +357,37 @@ const (
 	kubernetesGraceSeconds = 30
 )
 
+// reportGeneratorWriteRoutes says whether this process serves the code
+// generator's writing endpoints, and to whom.
+//
+// The endpoints are gated on the mode, and the shipped configuration says dev -
+// so the deployment most likely to be exposed is the one that changed nothing,
+// and the one least likely to go looking. Silence there would leave the gate
+// technically correct and practically useless.
+//
+// Nothing is said in demo mode. The routes are registered, but DemoEvn refuses
+// all three by name, so a warning would describe an exposure that is not there.
+func reportGeneratorWriteRoutes() {
+	if !generatorWriteRoutesNeedWarning() {
+		return
+	}
+	log.Warnf("the code generator's writing endpoints are served in mode %q: "+
+		"/api/v1/gen/{toproject,apitofile,todb} write Go and Vue source onto this host and rows "+
+		"into this database, and they are in CasbinExclude, so any account that can log in may "+
+		"call them. Set application.mode to prod or test on anything that is not a workstation.",
+		config.ApplicationConfig.Mode)
+}
+
+// generatorWriteRoutesNeedWarning reports whether there is an exposure to warn
+// about: the endpoints are served, and nothing else is refusing them.
+//
+// Split from the logging so the decision can be tested. A warning nobody can
+// make fire is indistinguishable from no warning at all, and this one exists
+// precisely for the case nobody is looking at.
+func generatorWriteRoutesNeedWarning() bool {
+	return otherrouter.GenWriteRoutesEnabled() && config.ApplicationConfig.Mode != "demo"
+}
+
 // reportShutdownBudget states what a shutdown will spend and whether it fits.
 //
 // The sum is taken from the resolved values, not from the configuration file: