From dd30420865841dc59b74c33344202aad7e0dad02 Mon Sep 17 00:00:00 2001
From: Sara Robinson <sararob@google.com>
Date: Thu, 9 Apr 2026 10:26:50 -0700
Subject: [PATCH] chore: Update user-agent header

PiperOrigin-RevId: 897181899
---
 tests/unit/vertexai/genai/replays/conftest.py |  9 ++++-
 vertexai/_genai/client.py                     | 39 ++++++++-----------
 2 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/tests/unit/vertexai/genai/replays/conftest.py b/tests/unit/vertexai/genai/replays/conftest.py
index efcf2d3002..0f9eed0c5b 100644
--- a/tests/unit/vertexai/genai/replays/conftest.py
+++ b/tests/unit/vertexai/genai/replays/conftest.py
@@ -23,6 +23,10 @@
     client as vertexai_genai_client_module,
 )
 from vertexai._genai import _agent_engines_utils
+from vertexai._genai.client import (
+    _GENAI_MODULES_TELEMETRY_HEADER,
+)
+from google.cloud.aiplatform import version as aip_version
 from google.cloud import storage, bigquery
 from google.genai import _replay_api_client
 from google.genai import types as genai_types
@@ -260,7 +264,10 @@ def client(use_vertex, replays_prefix, http_options, request):
         http_options = genai_types.HttpOptions()
     if http_options.headers is None:
         http_options.headers = {}
-    http_options.headers["x-goog-vertex-sdk"] = "true"
+
+    tracking_label = f"{_GENAI_MODULES_TELEMETRY_HEADER}/{aip_version.__version__}"
+    http_options.headers["user-agent"] = tracking_label
+    http_options.headers["x-goog-api-client"] = tracking_label
 
     replay_client = _replay_api_client.ReplayApiClient(
         mode=mode,
diff --git a/vertexai/_genai/client.py b/vertexai/_genai/client.py
index 29f81d2e0f..2e43782554 100644
--- a/vertexai/_genai/client.py
+++ b/vertexai/_genai/client.py
@@ -20,7 +20,6 @@
 
 import google.auth
 from google.cloud.aiplatform import version as aip_version
-from google.genai import _api_client
 from google.genai import _common
 from google.genai import client as genai_client
 from google.genai import types
@@ -41,27 +40,6 @@
 
 _GENAI_MODULES_TELEMETRY_HEADER = "vertex-genai-modules"
 
-genai_append_method = _api_client.append_library_version_headers
-
-
-def _add_tracking_headers(headers: dict[str, str]) -> None:
-    """Adds Vertex Gen AI tracking headers."""
-    is_vertex = headers.get(
-        "x-goog-vertex-sdk"
-    ) == "true" or "vertex-genai-modules" in headers.get("user-agent", "")
-    if is_vertex:
-        tracking_label = f"{_GENAI_MODULES_TELEMETRY_HEADER}/{aip_version.__version__}"
-
-        headers["user-agent"] = tracking_label
-        headers["x-goog-api-client"] = tracking_label
-
-        headers.pop("x-goog-vertex-sdk", None)
-    else:
-        genai_append_method(headers)
-
-
-_api_client.append_library_version_headers = _add_tracking_headers
-
 
 class AsyncClient:
     """Async Gen AI Client for the Vertex SDK."""
@@ -229,7 +207,22 @@ def __init__(
             http_options = types.HttpOptions()
         if http_options.headers is None:
             http_options.headers = {}
-        http_options.headers["x-goog-vertex-sdk"] = "true"
+
+        tracking_label = f"{_GENAI_MODULES_TELEMETRY_HEADER}/{aip_version.__version__}"
+
+        if "user-agent" in http_options.headers:
+            http_options.headers["user-agent"] = (
+                f"{http_options.headers['user-agent']} {tracking_label}"
+            )
+        else:
+            http_options.headers["user-agent"] = tracking_label
+
+        if "x-goog-api-client" in http_options.headers:
+            http_options.headers["x-goog-api-client"] = (
+                f"{http_options.headers['x-goog-api-client']} {tracking_label}"
+            )
+        else:
+            http_options.headers["x-goog-api-client"] = tracking_label
 
         self._api_client = genai_client.Client._get_api_client(
             vertexai=True,