diff --git a/model/custom.go b/model/custom.go
index 7fa45a4..c465134 100644
--- a/model/custom.go
+++ b/model/custom.go
@@ -8,10 +8,10 @@ import (
 
 // Custom as an compatible example.
 type Custom struct {
-	Inputer
-	Outputer
-	MessageBuilder[*DeepSeek]
-	sep string
+	Inputer                   `json:"-"`
+	Outputer                  `json:"-"`
+	MessageBuilder[*DeepSeek] `json:"-"`
+	sep                       string `json:"-"`
 	// callback only
 	ID      string   `json:"id,omitempty"`
 	Object  string   `json:"object,omitempty"`
diff --git a/model/deepseek.go b/model/deepseek.go
index ae282ef..f29821e 100644
--- a/model/deepseek.go
+++ b/model/deepseek.go
@@ -12,9 +12,9 @@ const (
 
 // DeepSeek as an specified example.
 type DeepSeek struct {
-	Inputer
-	Outputer
-	MessageBuilder[*DeepSeek]
+	Inputer                   `json:"-"`
+	Outputer                  `json:"-"`
+	MessageBuilder[*DeepSeek] `json:"-"`
 	// callback only
 	ID      string   `json:"id,omitempty"`
 	Object  string   `json:"object,omitempty"`