feat: add xAI handling and response processing

relay/helper/common.go

@@ -56,6 +56,9 @@ func StringData(c *gin.Context, str string) error {
 }
 
 func ObjectData(c *gin.Context, object interface{}) error {
+	if object == nil {
+		return errors.New("object is nil")
+	}
 	jsonData, err := json.Marshal(object)
 	if err != nil {
 		return fmt.Errorf("error marshalling object: %w", err)