feat: Mark Vertex calls made from non-gemini models

PiperOrigin-RevId: 864253424

Author: google-genai-bot

src/google/adk/models/anthropic_llm.py

@@ -36,6 +36,7 @@
 from pydantic import BaseModel
 from typing_extensions import override
 
+from ..utils._google_client_headers import get_tracking_headers
 from .base_llm import BaseLlm
 from .llm_response import LlmResponse
 
@@ -345,4 +346,5 @@ def _anthropic_client(self) -> AsyncAnthropicVertex:
     return AsyncAnthropicVertex(
         project_id=os.environ["GOOGLE_CLOUD_PROJECT"],
         region=os.environ["GOOGLE_CLOUD_LOCATION"],
+        default_headers=get_tracking_headers(),
     )

src/google/adk/models/google_llm.py

@@ -30,7 +30,8 @@
 from google.genai.errors import ClientError
 from typing_extensions import override
 
-from ..utils._client_labels_utils import get_client_labels
+from ..utils._google_client_headers import get_tracking_headers
+from ..utils._google_client_headers import merge_tracking_headers
 from ..utils.context_utils import Aclosing
 from ..utils.streaming_utils import StreamingResponseAggregator
 from ..utils.variant_utils import GoogleLLMVariant
@@ -316,13 +317,7 @@ def _api_backend(self) -> GoogleLLMVariant:
     )
 
   def _tracking_headers(self) -> dict[str, str]:
-    labels = get_client_labels()
-    header_value = ' '.join(labels)
-    tracking_headers = {
-        'x-goog-api-client': header_value,
-        'user-agent': header_value,
-    }
-    return tracking_headers
+    return get_tracking_headers()
 
   @cached_property
   def _live_api_version(self) -> str:
@@ -362,8 +357,10 @@ async def connect(self, llm_request: LlmRequest) -> BaseLlmConnection:
     ):
       if not llm_request.live_connect_config.http_options.headers:
         llm_request.live_connect_config.http_options.headers = {}
-      llm_request.live_connect_config.http_options.headers.update(
-          self._tracking_headers()
+      llm_request.live_connect_config.http_options.headers = (
+          self._merge_tracking_headers(
+              llm_request.live_connect_config.http_options.headers
+          )
       )
       llm_request.live_connect_config.http_options.api_version = (
           self._live_api_version
@@ -456,20 +453,7 @@ async def _preprocess_request(self, llm_request: LlmRequest) -> None:
 
   def _merge_tracking_headers(self, headers: dict[str, str]) -> dict[str, str]:
     """Merge tracking headers to the given headers."""
-    headers = headers or {}
-    for key, tracking_header_value in self._tracking_headers().items():
-      custom_value = headers.get(key, None)
-      if not custom_value:
-        headers[key] = tracking_header_value
-        continue
-
-      # Merge tracking headers with existing headers and avoid duplicates.
-      value_parts = tracking_header_value.split(' ')
-      for custom_value_part in custom_value.split(' '):
-        if custom_value_part not in value_parts:
-          value_parts.append(custom_value_part)
-      headers[key] = ' '.join(value_parts)
-    return headers
+    return merge_tracking_headers(headers)
 
 
 def _build_function_declaration_log(

src/google/adk/models/lite_llm.py

@@ -51,6 +51,7 @@
 from pydantic import Field
 from typing_extensions import override
 
+from ..utils._google_client_headers import merge_tracking_headers
 from .base_llm import BaseLlm
 from .llm_request import LlmRequest
 from .llm_response import LlmResponse
@@ -1699,6 +1700,18 @@ def _build_request_log(req: LlmRequest) -> str:
 """
 
 
+def _is_litellm_vertex_model(model_string: str) -> bool:
+  """Check if the model is a Vertex AI model accessed via LiteLLM.
+
+  Args:
+    model_string: A LiteLLM model string (e.g., "vertex_ai/gemini-2.5-flash")
+
+  Returns:
+    True if it's a Vertex AI model accessed via LiteLLM, False otherwise
+  """
+  return model_string.startswith("vertex_ai/")
+
+
 def _is_litellm_gemini_model(model_string: str) -> bool:
   """Check if the model is a Gemini model accessed via LiteLLM.
 
@@ -1867,6 +1880,14 @@ async def generate_content_async(
     }
     completion_args.update(self._additional_args)
 
+    # merge headers
+    if _is_litellm_vertex_model(effective_model) or _is_litellm_gemini_model(
+        effective_model
+    ):
+      completion_args["headers"] = merge_tracking_headers(
+          completion_args.get("headers")
+      )
+
     if generation_params:
       completion_args.update(generation_params)
 

src/google/adk/utils/_google_client_headers.py

@@ -0,0 +1,56 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import annotations
+
+from ._client_labels_utils import get_client_labels
+
+
+def get_tracking_headers() -> dict[str, str]:
+  """Returns a dictionary of HTTP headers for tracking API requests.
+
+  These headers are used to identify HTTP calls made by ADK towards
+   Vertex AI LLM APIs.
+  """
+  labels = get_client_labels()
+  header_value = " ".join(labels)
+  return {
+      "x-goog-api-client": header_value,
+      "user-agent": header_value,
+  }
+
+
+def merge_tracking_headers(headers: dict[str, str] | None) -> dict[str, str]:
+  """Merge tracking headers to the given headers.
+
+  Args:
+    headers: headers to merge tracking headers into.
+
+  Returns:
+    A dictionary of HTTP headers with tracking headers merged.
+  """
+  new_headers = (headers or {}).copy()
+  for key, tracking_header_value in get_tracking_headers().items():
+    custom_value = new_headers.get(key, None)
+    if not custom_value:
+      new_headers[key] = tracking_header_value
+      continue
+
+    # Merge tracking headers with existing headers and avoid duplicates.
+    value_parts = tracking_header_value.split(" ")
+    for custom_value_part in custom_value.split(" "):
+      if custom_value_part not in value_parts:
+        value_parts.append(custom_value_part)
+    new_headers[key] = " ".join(value_parts)
+  return new_headers

tests/unittests/models/test_anthropic_llm.py

@@ -391,6 +391,31 @@ async def mock_coro():
       assert responses[0].content.parts[0].text == "Hello, how can I help you?"
 
 
+def test_claude_vertex_client_uses_tracking_headers():
+  """Tests that Claude vertex client is called with tracking headers."""
+  with mock.patch.object(
+      anthropic_llm, "AsyncAnthropicVertex", autospec=True
+  ) as mock_anthropic_vertex:
+    with mock.patch.dict(
+        os.environ,
+        {
+            "GOOGLE_CLOUD_PROJECT": "test-project",
+            "GOOGLE_CLOUD_LOCATION": "us-central1",
+        },
+    ):
+      instance = Claude(model="claude-3-5-sonnet-v2@20241022")
+      _ = instance._anthropic_client
+      mock_anthropic_vertex.assert_called_once()
+      _, kwargs = mock_anthropic_vertex.call_args
+      assert "default_headers" in kwargs
+      assert "x-goog-api-client" in kwargs["default_headers"]
+      assert "user-agent" in kwargs["default_headers"]
+      assert (
+          f"google-adk/{adk_version.__version__}"
+          in kwargs["default_headers"]["user-agent"]
+      )
+
+
 @pytest.mark.asyncio
 async def test_generate_content_async_with_max_tokens(
     llm_request, generate_content_response, generate_llm_response

tests/unittests/models/test_google_llm.py

@@ -31,6 +31,7 @@
 from google.adk.models.llm_response import LlmResponse
 from google.adk.utils._client_labels_utils import _AGENT_ENGINE_TELEMETRY_ENV_VARIABLE_NAME
 from google.adk.utils._client_labels_utils import _AGENT_ENGINE_TELEMETRY_TAG
+from google.adk.utils._google_client_headers import get_tracking_headers
 from google.adk.utils.variant_utils import GoogleLLMVariant
 from google.genai import types
 from google.genai.errors import ClientError
@@ -469,7 +470,7 @@ async def test_generate_content_async_with_custom_headers(
   """Test that tracking headers are updated when custom headers are provided."""
   # Add custom headers to the request config
   custom_headers = {"custom-header": "custom-value"}
-  tracking_headers = gemini_llm._tracking_headers()
+  tracking_headers = get_tracking_headers()
   for key in tracking_headers:
     custom_headers[key] = "custom " + tracking_headers[key]
   llm_request.config.http_options = types.HttpOptions(headers=custom_headers)
@@ -494,7 +495,7 @@ async def mock_coro():
     config_arg = call_args.kwargs["config"]
 
     for key, value in config_arg.http_options.headers.items():
-      tracking_headers = gemini_llm._tracking_headers()
+      tracking_headers = get_tracking_headers()
       if key in tracking_headers:
         assert value == tracking_headers[key] + " custom"
       else:
@@ -545,7 +546,7 @@ async def mock_coro():
     config_arg = call_args.kwargs["config"]
 
     expected_headers = custom_headers.copy()
-    expected_headers.update(gemini_llm._tracking_headers())
+    expected_headers.update(get_tracking_headers())
     assert config_arg.http_options.headers == expected_headers
 
     assert len(responses) == 2
@@ -599,7 +600,7 @@ async def mock_coro():
     assert final_config.http_options is not None
     assert (
         final_config.http_options.headers["x-goog-api-client"]
-        == gemini_llm._tracking_headers()["x-goog-api-client"]
+        == get_tracking_headers()["x-goog-api-client"]
     )
 
     assert len(responses) == 2 if stream else 1
@@ -633,7 +634,7 @@ def test_live_api_client_properties(gemini_llm):
     assert http_options.api_version == "v1beta1"
 
     # Check that tracking headers are included
-    tracking_headers = gemini_llm._tracking_headers()
+    tracking_headers = get_tracking_headers()
     for key, value in tracking_headers.items():
       assert key in http_options.headers
       assert value in http_options.headers[key]
@@ -671,7 +672,7 @@ async def __aexit__(self, *args):
 
       # Verify that tracking headers were merged with custom headers
       expected_headers = custom_headers.copy()
-      expected_headers.update(gemini_llm._tracking_headers())
+      expected_headers.update(get_tracking_headers())
       assert config_arg.http_options.headers == expected_headers
 
       # Verify that API version was set

tests/unittests/models/test_litellm.py

@@ -2849,11 +2849,12 @@ def test_model_response_to_chunk(
 async def test_acompletion_additional_args(mock_acompletion, mock_client):
   lite_llm_instance = LiteLlm(
       # valid args
-      model="test_model",
+      model="vertex_ai/test_model",
       llm_client=mock_client,
       api_key="test_key",
       api_base="some://url",
       api_version="2024-09-12",
+      headers={"custom": "header"},  # Add custom header to test merge
       # invalid args (ignored)
       stream=True,
       messages=[{"role": "invalid", "content": "invalid"}],
@@ -2880,13 +2881,43 @@ async def test_acompletion_additional_args(mock_acompletion, mock_client):
 
   _, kwargs = mock_acompletion.call_args
 
-  assert kwargs["model"] == "test_model"
+  assert kwargs["model"] == "vertex_ai/test_model"
   assert kwargs["messages"][0]["role"] == "user"
   assert kwargs["messages"][0]["content"] == "Test prompt"
   assert kwargs["tools"][0]["function"]["name"] == "test_function"
   assert "stream" not in kwargs
   assert "llm_client" not in kwargs
   assert kwargs["api_base"] == "some://url"
+  assert "headers" in kwargs
+  assert kwargs["headers"]["custom"] == "header"
+  assert "x-goog-api-client" in kwargs["headers"]
+  assert "user-agent" in kwargs["headers"]
+
+
+@pytest.mark.asyncio
+async def test_acompletion_additional_args_non_vertex(
+    mock_acompletion, mock_client
+):
+  """Test that tracking headers are not added for non-Vertex AI models."""
+  lite_llm_instance = LiteLlm(
+      model="openai/gpt-4o",
+      llm_client=mock_client,
+      api_key="test_key",
+      headers={"custom": "header"},
+  )
+
+  async for _ in lite_llm_instance.generate_content_async(
+      LLM_REQUEST_WITH_FUNCTION_DECLARATION
+  ):
+    pass
+
+  mock_acompletion.assert_called_once()
+  _, kwargs = mock_acompletion.call_args
+  assert kwargs["model"] == "openai/gpt-4o"
+  assert "headers" in kwargs
+  assert kwargs["headers"]["custom"] == "header"
+  assert "x-goog-api-client" not in kwargs["headers"]
+  assert "user-agent" not in kwargs["headers"]
 
 
 @pytest.mark.asyncio