diff --git a/app/models/grok_models.py b/app/models/grok_models.py
index 6fab827..b067c54 100644
--- a/app/models/grok_models.py
+++ b/app/models/grok_models.py
@@ -103,7 +103,7 @@ _MODEL_CONFIG: Dict[str, Dict[str, Any]] = {
         "cost": {"type": "low_cost", "multiplier": 1, "description": "计1次调用"},
         "requires_super": False,
         "display_name": "Grok Imagine 0.9",
-        "description": "Video generation model powered by Grok",
+        "description": "Image and video generation model. Supports text-to-image and image-to-video generation.",
         "raw_model_path": "xai/grok-imagine-0.9",
         "default_temperature": 1.0,
         "default_max_output_tokens": 8192,
diff --git a/app/services/grok/client.py b/app/services/grok/client.py
index 456bdfb..277d640 100644
--- a/app/services/grok/client.py
+++ b/app/services/grok/client.py
@@ -188,7 +188,8 @@ class GrokClient:
             # 构建请求
             headers = GrokClient._build_headers(token)
             if model == "grok-imagine-0.9":
-                ref_id = post_id or payload.get("fileAttachments", [""])[0]
+                file_attachments = payload.get("fileAttachments", [])
+                ref_id = post_id or (file_attachments[0] if file_attachments else "")
                 if ref_id:
                     headers["Referer"] = f"https://grok.com/imagine/{ref_id}"