diff --git a/conversion/requests/chatgpt/convert.go b/conversion/requests/chatgpt/convert.go
index daf12d4..3b9cb18 100644
--- a/conversion/requests/chatgpt/convert.go
+++ b/conversion/requests/chatgpt/convert.go
@@ -25,7 +25,7 @@ func ConvertAPIRequest(api_request official_types.APIRequest, account string, se
 		chatgpt_request.ConversationMode.Kind = "gizmo_interaction"
 		chatgpt_request.ConversationMode.GizmoId = "g-" + matches[1]
 	}
-	ifMultimodel := secret.Token != ""
+	ifMultimodel := strings.HasPrefix(api_request.Model, "gpt-4")
 	for _, api_message := range api_request.Messages {
 		if api_message.Role == "system" {
 			api_message.Role = "critic"
diff --git a/typings/chatgpt/request.go b/typings/chatgpt/request.go
index 7213bda..f57f5ec 100644
--- a/typings/chatgpt/request.go
+++ b/typings/chatgpt/request.go
@@ -91,7 +91,7 @@ type FileResult struct {
 	Filesize int
 	Isimage  bool
 	Bounds   [2]int
-	// Current file max-age 1 year
+	// Current file max-age 30 days
 	Upload int64
 }
 
@@ -289,7 +289,7 @@ func processUrl(urlstr string, account string, secret *tokens.Secret, deviceId s
 	hasher := sha1.New()
 	hasher.Write(binary)
 	hash := account + secret.TeamUserID + hex.EncodeToString(hasher.Sum(nil))
-	if fileHashPool[hash] != nil && time.Now().Unix() < fileHashPool[hash].Upload+31536000 {
+	if fileHashPool[hash] != nil && time.Now().Unix() < fileHashPool[hash].Upload+2592000 {
 		return fileHashPool[hash]
 	}
 	isImg := strings.HasPrefix(mimeType, "image")
@@ -319,7 +319,7 @@ func processDataUrl(data string, account string, secret *tokens.Secret, deviceId
 	hasher := sha1.New()
 	hasher.Write(binary)
 	hash := account + secret.TeamUserID + hex.EncodeToString(hasher.Sum(nil))
-	if fileHashPool[hash] != nil && time.Now().Unix() < fileHashPool[hash].Upload+31536000 {
+	if fileHashPool[hash] != nil && time.Now().Unix() < fileHashPool[hash].Upload+2592000 {
 		return fileHashPool[hash]
 	}
 	startIdx := strings.Index(data, ":")