diff --git a/src/provider/core/chat.ts b/src/provider/core/chat.ts
index 697e1ba..ea30365 100644
--- a/src/provider/core/chat.ts
+++ b/src/provider/core/chat.ts
@@ -50,10 +50,10 @@ export class BaseChat implements BaseChatInterface, Usage {
    * 默认apiKey
    */
   apiKey: string;
-  prompt_tokens: number;
-  total_tokens: number;
-  completion_tokens: number;
-  responseText: string;
+  prompt_tokens: number = 0;
+  total_tokens: number = 0;
+  completion_tokens: number = 0;
+  responseText: string = '';
   utils = AIUtils;
   constructor(options: BaseChatOptions) {
     this.baseURL = options.baseURL;
@@ -105,9 +105,8 @@ export class BaseChat implements BaseChatInterface, Usage {
 
     const res = await response.json() as ChatMessageComplete;
 
-    this.prompt_tokens = res.usage?.prompt_tokens ?? 0;
-    this.total_tokens = res.usage?.total_tokens ?? 0;
-    this.completion_tokens = res.usage?.completion_tokens ?? 0;
+    this.setChatUsage(res.usage);
+    
     this.responseText = res.choices[0]?.message?.content || '';
     return res;
   }
@@ -191,6 +190,11 @@ export class BaseChat implements BaseChatInterface, Usage {
       completion_tokens: this.completion_tokens,
     };
   }
+  setChatUsage(usage: { prompt_tokens?: number; total_tokens?: number; completion_tokens?: number }) {
+    this.prompt_tokens = usage.prompt_tokens ?? this.prompt_tokens;
+    this.total_tokens = usage.total_tokens ?? this.total_tokens;
+    this.completion_tokens = usage.completion_tokens ?? this.completion_tokens;
+  }
 
   getHeaders(headers?: Record<string, string>) {
     return {