diff --git a/par-api/src/main/java/com/par/api/controller/AccessResultController.java b/par-api/src/main/java/com/par/api/controller/AccessResultController.java
index 97063e8..5e69047 100644
--- a/par-api/src/main/java/com/par/api/controller/AccessResultController.java
+++ b/par-api/src/main/java/com/par/api/controller/AccessResultController.java
@@ -36,7 +36,7 @@ public class AccessResultController {
             HttpServletRequest request) {
 
         String configVersion = (String) payload.get("configVersion");
-        String contentType = (String) payload.getOrDefault("contentType", "html");
+        String contentType = (String) payload.getOrDefault("contentType", detectContentType(payload.get("content")));
         String content = (String) payload.get("content");
         String url = (String) payload.get("url");
         Integer statusCode = payload.get("statusCode") instanceof Integer i ? i : null;
@@ -149,4 +149,12 @@ public class AccessResultController {
             return ApiResponse.error(404, e.getMessage());
         }
     }
+
+    private String detectContentType(Object content) {
+        if (content instanceof String s) {
+            String t = s.trim();
+            if (t.startsWith("{") || t.startsWith("[")) return "json";
+        }
+        return "html";
+    }
 }