diff --git a/backend/api/server.py b/backend/api/server.py
index 8f3d3f4..9ec147d 100644
--- a/backend/api/server.py
+++ b/backend/api/server.py
@@ -65,6 +65,11 @@ VALIDATED_CHAT_MODEL_PROVIDERS = {
     'zhipuai',
 }
 
+UNSUPPORTED_CHAT_MODEL_PREFIXES: tuple[tuple[str, str], ...] = (
+    # /models 会返回这批 ppio 模型，但 /chat/completions 实测不支持。
+    ('ppio', 'pa/claude-'),
+)
+
 # WebUI 的快速入口只展示可以通过对话输入框安全执行的 slash command。
 # 这些命令仍然保留在终端 `/` 列表里，但不适合作为 WebUI 快捷项。
 WEBUI_HIDDEN_SLASH_COMMANDS = {
@@ -1547,6 +1552,8 @@ def _normalize_model_list(payload: Any) -> list[dict[str, str]]:
         )
         if provider and provider not in VALIDATED_CHAT_MODEL_PROVIDERS:
             continue
+        if _is_known_unsupported_chat_model(provider, model_id):
+            continue
         normalized = _normalize_model_id(model_id, provider=provider)
         if normalized is not None:
             entry = {'id': normalized}
@@ -1579,6 +1586,15 @@ def _normalize_model_id(model: str, *, provider: str | None = None) -> str | Non
     return value
 
 
+def _is_known_unsupported_chat_model(provider: str | None, model_id: str) -> bool:
+    provider_key = (provider or '').strip().lower()
+    model_key = model_id.strip().lower()
+    return any(
+        provider_key == blocked_provider and model_key.startswith(blocked_prefix)
+        for blocked_provider, blocked_prefix in UNSUPPORTED_CHAT_MODEL_PREFIXES
+    )
+
+
 def _is_llm_model(model_id: str, model_type: str | None) -> bool:
     lower = model_id.strip().lower()
     blocked_fragments = (
diff --git a/tests/test_model_list.py b/tests/test_model_list.py
index fe6677c..24c27c1 100644
--- a/tests/test_model_list.py
+++ b/tests/test_model_list.py
@@ -56,6 +56,18 @@ class ModelListTests(unittest.TestCase):
                     'owned_by': 'siliconflow',
                     'model_type': 'llm',
                 },
+                {
+                    'id': 'pa/claude-opus-4-7',
+                    'object': 'model',
+                    'owned_by': 'ppio',
+                    'model_type': 'llm',
+                },
+                {
+                    'id': 'gemini-2.0-flash-20250609',
+                    'object': 'model',
+                    'owned_by': 'ppio',
+                    'model_type': 'llm',
+                },
             ]
         }
 
@@ -65,6 +77,7 @@ class ModelListTests(unittest.TestCase):
             [model['id'] for model in models],
             [
                 'azure_openai/gpt-5',
+                'ppio/gemini-2.0-flash-20250609',
                 'siliconflow/Pro/deepseek-ai/DeepSeek-V3',
                 'xiaomi/DeepSeek-R1-0528',
             ],