diff --git a/gin.go b/gin.go
index 94b5b78..5e84f06 100644
--- a/gin.go
+++ b/gin.go
@@ -21,4 +21,5 @@ const (
 	GinRecordResponseDataField = "record_response_data" // 记录响应数据到上下文
 	GinRecordRequestDataField  = "record_request_data"  // 记录请求数据到上下文
 	GinRequestIsSuccessField   = "request_is_success"   // 请求是否成功
+	GinResponseExtensionField  = "extension_data"       // 扩展数据字段
 )