diff --git a/app/agent/llm/discovery.py b/app/agent/llm/discovery.py
index f65435667..0b1050fab 100644
--- a/app/agent/llm/discovery.py
+++ b/app/agent/llm/discovery.py
@@ -397,9 +397,15 @@ class _ProviderDiscovery:
             connect_timeout=10,
             trust_env=False,
         )
+        # google-genai 的 aiohttp 请求已经显式传入 timeout，不能再从
+        # async_client_args 透传同名参数，否则会触发重复关键字异常。
+        async_client_args = {
+            key: value for key, value in client_args.items() if key != "timeout"
+        }
         http_options = HttpOptions(
+            timeout=15_000,
             client_args=client_args,
-            async_client_args=client_args,
+            async_client_args=async_client_args,
         )
 
         client = genai.Client(api_key=api_key, http_options=http_options)
diff --git a/tests/test_llm_provider_transport.py b/tests/test_llm_provider_transport.py
index 3948d9a73..ae849dbdb 100644
--- a/tests/test_llm_provider_transport.py
+++ b/tests/test_llm_provider_transport.py
@@ -136,8 +136,10 @@ def test_google_model_client_uses_adapter_args_and_closes_both_clients(
     client = captured["client"]
     http_options = captured["http_options"]
     assert result[0]["id"] == "gemini-test"
+    assert http_options.timeout == 15_000
     assert http_options.client_args["trust_env"] is False
     assert http_options.async_client_args["trust_env"] is False
+    assert "timeout" not in http_options.async_client_args
     assert any(
         key in http_options.async_client_args for key in ("proxy", "proxies")
     )