collect usage

llm/openai_compatible/chat.go

@@ -119,6 +119,9 @@ func (o *OpenAICompatible) Chat(ctx context.Context, chatReq llm.ChatRequest) (*
 		return nil, err
 	}
 
+	if o.tokenUsage.Model == "" && chatResp.Model != "" {
+		o.tokenUsage.Model = chatResp.Model
+	}
 	o.tokenUsage.PromptTokens = chatResp.Usage.PromptTokens
 	o.tokenUsage.CompletionTokens = chatResp.Usage.CompletionTokens
 	o.tokenUsage.TotalTokens = chatResp.Usage.TotalTokens