diff --git a/controllers/message.go b/controllers/message.go
index c766e54..fb77e9a 100644
--- a/controllers/message.go
+++ b/controllers/message.go
@@ -137,7 +137,7 @@ func (c *ApiController) GetMessageAnswer() {
 		return
 	}
 
-	if provider.Category != "AI" || provider.ClientSecret == "" {
+	if provider.Category != "Model" || provider.ClientSecret == "" {
 		c.ResponseErrorStream(fmt.Sprintf("The provider: %s is invalid", providerId))
 		return
 	}
diff --git a/object/chat.go b/object/chat.go
index 702cb5f..6553f73 100644
--- a/object/chat.go
+++ b/object/chat.go
@@ -96,6 +96,17 @@ func UpdateChat(id string, chat *Chat) (bool, error) {
 }
 
 func AddChat(chat *Chat) (bool, error) {
+	if chat.Type == "AI" && chat.User2 == "" {
+		provider, err := getDefaultModelProvider()
+		if err != nil {
+			return false, err
+		}
+
+		if provider != nil {
+			chat.User2 = provider.Name
+		}
+	}
+
 	affected, err := adapter.engine.Insert(chat)
 	if err != nil {
 		return false, err
diff --git a/object/provider.go b/object/provider.go
index 25983bc..a8da123 100644
--- a/object/provider.go
+++ b/object/provider.go
@@ -100,6 +100,20 @@ func GetProvider(id string) (*Provider, error) {
 	return getProvider(owner, name)
 }
 
+func getDefaultModelProvider() (*Provider, error) {
+	provider := Provider{Owner: "admin", Category: "Model"}
+	existed, err := adapter.engine.Get(&provider)
+	if err != nil {
+		return &provider, err
+	}
+
+	if !existed {
+		return nil, nil
+	}
+
+	return &provider, nil
+}
+
 func UpdateProvider(id string, provider *Provider) (bool, error) {
 	owner, name := util.GetOwnerAndNameFromId(id)
 	_, err := getProvider(owner, name)