diff --git a/cmd/server/main.go b/cmd/server/main.go
index 499f613..a172510 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -302,6 +302,7 @@ func openAPISpecHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func diagramHandler(w http.ResponseWriter, r *http.Request) {
+	log.Printf("[diagram] %s %s from %s", r.Method, r.URL.String(), r.RemoteAddr)
 	if r.Method == http.MethodOptions {
 		addCORS(w)
 		w.WriteHeader(http.StatusNoContent)
@@ -309,16 +310,19 @@ func diagramHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	id := r.URL.Query().Get("id")
 	if id == "" {
+		log.Printf("[diagram] missing id")
 		http.Error(w, "missing id", http.StatusBadRequest)
 		return
 	}
 	xml, ok := diagramStore.data[id]
 	if !ok {
+		log.Printf("[diagram] id not found: %s", id)
 		http.Error(w, "not found", http.StatusNotFound)
 		return
 	}
 	addCORS(w)
 	w.Header().Set("Content-Type", "application/xml")
+	log.Printf("[diagram] served id %s bytes=%d", id, len(xml))
 	_, _ = w.Write([]byte(xml))
 }