diff --git a/agent/internal/httpapi/uiconfig.go b/agent/internal/httpapi/uiconfig.go
index b9c281d..b2b4d6a 100644
--- a/agent/internal/httpapi/uiconfig.go
+++ b/agent/internal/httpapi/uiconfig.go
@@ -70,13 +70,28 @@ func (s *Server) handleConfigUIState(w http.ResponseWriter, r *http.Request) {
 	}
 
 	root, _ := readUIRootConfig(s.agentCfg.ConfigPath)
+
 	// Force templates/instances-only view.
+	// templates = union(current templates, built-in templates)
+	tplKeys := map[string]bool{}
+	for k := range root.Templates {
+		tplKeys[k] = true
+	}
+	for k := range uiTemplates() {
+		tplKeys[k] = true
+	}
+	mergedTpls := make([]string, 0, len(tplKeys))
+	for k := range tplKeys {
+		mergedTpls = append(mergedTpls, k)
+	}
+	sort.Strings(mergedTpls)
+
 	resp := map[string]any{
 		"ok":        true,
 		"global":    root.Global,
 		"queue":     root.Queue,
 		"instances": root.Instances,
-		"templates": sortedKeys(uiTemplates()),
+		"templates": mergedTpls,
 	}
 	writeJSON(w, http.StatusOK, resp)
 }
@@ -145,7 +160,18 @@ func (s *Server) planUIConfig(req uiPlanRequest) (uiPlanResponse, error) {
 	}
 
 	warnings := []string{}
-	tpls := uiTemplates()
+
+	// Allow both built-in templates and templates already present in the current config.
+	// Merge rule: keep existing templates as-is; add built-in templates if missing.
+	tpls := map[string]any{}
+	for k, v := range cur.Templates {
+		tpls[k] = v
+	}
+	for k, v := range uiTemplates() {
+		if _, ok := tpls[k]; !ok {
+			tpls[k] = v
+		}
+	}
 
 	seen := map[string]bool{}
 	for i := range req.Instances {
@@ -239,6 +265,11 @@ func readUIRootConfig(path string) (uiRootConfig, error) {
 	b, err := os.ReadFile(path)
 	if err != nil {
 		if os.IsNotExist(err) {
+			// Return a well-formed empty state.
+			out.Instances = []UIInstance{}
+			out.Global = map[string]any{}
+			out.Queue = map[string]any{}
+			out.Templates = map[string]any{}
 			return out, nil
 		}
 		return out, err
@@ -253,6 +284,9 @@ func readUIRootConfig(path string) (uiRootConfig, error) {
 	if out.Queue == nil {
 		out.Queue = map[string]any{}
 	}
+	if out.Templates == nil {
+		out.Templates = map[string]any{}
+	}
 	return out, nil
 }
 
diff --git a/agent/rk3588-agent b/agent/rk3588-agent
index 259128d..621365c 100644
Binary files a/agent/rk3588-agent and b/agent/rk3588-agent differ